This article takes an in depth look at gears and their applications.
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A gear is a rotary circular mechanism with teeth in its structure, designed to transfer torque and speed from one shaft to another.
Gears, also known as cogs, have teeth cut into the cogwheel or gear wheel. These teeth mesh together to transfer torque and speed. Gears are mechanical devices that operate on the lever principle, allowing changes in direction, speed, and torque of the power device. As simple machines, gears come in various sizes, each producing different amounts of torque, thereby providing a mechanical advantage. The speed depends on the rotational speed and diameter of the two meshed gears. All gear teeth are shaped the same and are evenly spaced to provide torque and prevent slipping. When two or more meshing gears work in sequence, they form a transmission or gear train. A linear toothed strip is called a rack, and when gears mesh in a linear direction, they produce translation.
Gears can be classified by both shape and shaft position. The shapes of gears can be involute, cycloid, or trochoidal. Regarding shaft positions, gears can be categorized as parallel shaft gears, intersecting shaft gears, or non-parallel/non-intersecting shaft gears. Gears are usually mounted on objects or attached to them using shafts or a base. Typically, the toothed component is fixed to the shaft, and when a driving force is applied, the shaft rotates. This rotation causes the driven gear to also rotate, resulting in a rotary motion. Gears are characterized by their radius and the number of teeth they have.
The gear radius varies depending on which part of the gear is being examined. The most relevant measurements are the root radius and the addendum radius. The root radius is measured from the center of the gear to the base of the teeth and defines the cutter fillet radius, which is the fillet curve at the base of a gear tooth next to the cutter tooth tip. This fillet is a critical part of the gear, as it must endure maximum bending stress concentration, and it cannot always be accurately measured. The difference between these measurements is crucial for understanding the gear's geometry and performance.
The addendum radius is the height a tooth extends beyond the pitch circle or pitch line, measured from the center of the gear to the top of the tooth. The addendum circle, which includes the addendum radius, represents the outer boundary for external gears and the inner boundary for internal gears. The addendum radius is also referred to as the pitch radius, as it is the distance from the center of the gear to the pitch point.
The dimensions of the radius vary depending on the type of gear. The pitch radius and addendum radius contribute to the diameter of the pitch circle.
The teeth of gears are the components that enable contact with other gears, facilitating a change in motion. The pitch, defined as the distance between identical points on adjacent gear teeth, is a key measurement in gear design. Gears are fundamentally defined by their teeth, which are crucial in preventing slippage during power transmission. Historically, gear teeth have been known as cogs, with their structure, placement, and profile being integral to the performance and functionality of the gear.
Gear teeth are typically cut into a blank but can also be inserted individually. When gears are made from blanks, the entire gear must be replaced if the teeth weaken and fail. The type of gear determines the placement and angle of the teeth, which can be either straight or helical. Teeth can be positioned around the outer circumference of the gear, internally on the inner portion, or flattened around the circumference.
While the basic structure of gear teeth may appear simple, it involves complex considerations and precise mathematical calculations to determine their exact design.
Involute gear teeth are the most commonly used for both drive and driven gears. Their shape is determined by the diameter of the base circle. Standard involute teeth can mesh with any gear that has the same pitch, pressure angle, and helix angle. Contact occurs at a single point where two involutes of the same spiral intersect.
Some of the factors used in the design of gear teeth include:
Gears are used to transfer rotational motion from one axis to another and to modify the output speed of a shaft. They are particularly effective for handling high loads because their teeth provide precise control over shaft movement.
Addendum - The teeth of gears extend outward for external gears and inward for internal gears from the pitch circle. This extension, known as the addendum, is the radial distance between the pitch diameter and the outer diameter of the gear. The tops of the gear teeth define the addendum circle.
Axis - The axis determines the direction of gear movement and how that motion is transmitted. Parallel axes are the most common configuration, where two axes remain parallel to each other. In contrast, intersecting axes are perpendicular and are used to alter the direction of motion. While parallel and intersecting axes are the most common, there are also gears with non-parallel and non-intersecting axes.
Base Circle - The base circle is a theoretical construct used to generate the involute curve, which is essential for creating gear tooth profiles.
Circular Pitch - TThe circular pitch is the distance measured along the pitch circle from a fixed point on one tooth to the same fixed point on an adjacent tooth. This measurement is taken along an arc rather than a straight line due to the curvature of the gear. For gears to mesh properly, the circular pitch, or the space between the teeth, must be equal for both gears.
Since the formula for calculating circular pitch involves π (pi), the module—a unit for gear tooth size—is used to simplify calculations. Modules are easier to work with than circular pitch because they are rational numbers.
Dedendum - The dedendum is the depth of a gear tooth between the pitch circle and the minor or inside diameter.
Diametral Pitch (DP) - The diametral pitch is the ratio of the number of teeth to the pitch diameter. For gears to mesh correctly, they must have the same diametral pitch. In the United States and the United Kingdom, it is expressed as the number of teeth per inch. As the number of teeth per inch increases, the profile of the teeth becomes smaller. Thus, a larger diametral pitch value results in smaller teeth on the gear.
Fillet - The gear tooth fillet, also known as the trochoid, is formed as a byproduct of the gear cutting process and is located just before the cutter tip impression on a gear tooth.
Form Diameter - The form diameter, or involute form diameter (TIF), is an imaginary circle created by connecting the trochoid or fillet curves of a gear's teeth. This diameter is smaller than the base circle diameter.
Gear Ratio - The gear ratio shows how many times a gear must turn for another gear to complete one full rotation. It directly measures the ratio of the rotational speeds between two or more interlocking gears. If the drive gear receiving power is larger than the driven gear, the driven gear will rotate faster. Conversely, if the drive gear is smaller than the driven gear, the drive gear will turn faster.
Pitch Circle - The pitch circle defines the size of a gear and must be tangent to another gear to ensure proper meshing. It is an imaginary circle that passes through the teeth of a gear, with a radius that allows it to make contact with a similar circle on a mating gear.
Pitch Diameter - The pitch diameter, identified by dm or d2, is the diameter of the pitch circle and is used to calculate how far away two gears should be from one another. It is equal to the widths of the threads and grooves. The pitch diameter is the width of the cylinder as it intersects the major and minor diameter or pitch line. It is an important part of determining the compatibility of gears and used as a frame of reference for thread measurement.
Pressure Angle - The pressure angle is the angle between a line tangent to the pitch circle and a normal line to the tooth profile at the pitch circle. It is determined by the tool used to shape the involute curve of the gear teeth. Standard pressure angles are 14.5°, 20°, and 25°. This angle affects how gears engage and how force is distributed along the teeth. For two gears to mesh properly, they must have the same pressure angle.
Teeth - Gear teeth can project outward or inward depending on the gear design. When teeth project outward, they are located on the circumference of the gear and are used to transmit rotation. In contrast, inward-projecting teeth form internal gears, which mesh with external gears and are commonly used in planetary gear systems.
The definition of gears is largely based on the profile of their teeth, which typically feature an involute curve. Other profiles include the cycloidal and trochoidal tooth shapes, which are specialized for specific applications. The involute profile is particularly effective for transmitting power smoothly.
The profile of a gear tooth is one side of a tooth’s cross section between the outside circle and the root circl
Top Land - The top land of a gear tooth is the flat surface at the tooth's tip. Its width, known as the face width, matches the spacing between adjacent teeth.
Tooth Thickness - The tooth thickness (ts) is the arc length between the opposing faces of a tooth, measured along the pitch circle. It is calculated from other dimensions of the gear teeth rather than measured directly.
Tooth Face - The tooth face is the mating surface located between the addendum circle and the pitch circle. It refers to the portion of the tooth that extends beyond the pitch surface.
Tooth Flank - The tooth flank is the surface between the tip and root surfaces of a gear tooth. It includes the addendum flank, dedendum flank, and blending surface.
Fillet Radius - The fillet radius of a gear tooth, located at its base, is the area where bending stress concentration is highest. It features a subtle profile and can be challenging to define and inspect.
Tooth Pitch - Tooth pitch is the distance between two points on adjacent teeth, measured at the pitch line. It is described using terms such as diametral pitch, circular pitch, and module. In the United States, diametral pitch is the most commonly used measurement.
Pitch Point - The pitch point of a gear tooth is the point where the pitch circles of two meshing gears are tangent to each other, located on the line of centers. The position of the pitch point determines the velocity ratio between the two gears.
Face Width - The face width is the length of a gear tooth along its axial plane. Increasing the face width enhances both the tooth's bending strength and surface strength. If the face width is smaller than the mating part, this portion is referred to as the effective face width.
Gears are mechanical devices, typically circular, with teeth around their edges or on their tops. They are used in various machines to transmit rotational force and torque. Gears operate in pairs, with the teeth of one gear engaging with those of the other to prevent slipping. When gear pairs are circular, the rotational speed and torque produced remain constant. However, if the gears are non-circular, the speed and torque ratio can vary.
To maintain constant speed and consistent torque, it is crucial to precisely shape the gear profile. When the smaller gear, known as the pinion, is the driving gear, it will reduce speed and increase torque. Conversely, if the pinion is on the driven shaft, the speed will increase while the torque decreases. The shafts that hold the gear pairs should be positioned close together but with sufficient spacing. These shafts can be parallel, non-parallel, intersecting, or non-intersecting. Gears connect through rotating shafts, which function as levers. The primary purpose of gears is to transfer energy or rotation from one part to another. Multiple gears can be connected simultaneously. In gear systems, three key outcomes can occur:
When two meshed gears are involved, with one having 40 teeth and the other 20 teeth, the smaller gear with 20 teeth will rotate at twice the speed of the larger gear with 40 teeth to maintain synchronization. This leads to higher speed but reduced force for the smaller gear.
If the smaller gear has more teeth than the larger one, its speed will decrease and the force will increase. This means that the smaller gear will require more force to rotate.
When two interconnected gears rotate, one will turn clockwise while the other turns counterclockwise. To change the direction of rotation or angles, specialized gears designed for this purpose are required.
Industrial applications use a variety of gears, each designed for specific purposes. The main characteristics that vary among these gears include:
Most gears are typically circular in shape, though they can also be elliptical, triangular, or square. Circular gears provide a consistent gear ratio, meaning the input ratio directly translates to the output ratio, applicable to both rotational speed and torque. In contrast, non-circular gears result in a variable gear ratio, causing the speed and torque to fluctuate, alternately increasing and decreasing.
The design and configuration of gear teeth are crucial characteristics of a gear. Each type of gear has a distinct tooth design, which is influenced by factors such as:
The structure of gear teeth depends on the type of gear and its intended application. Teeth can either be cut directly into the gear or inserted separately. Over time, teeth may wear out. If the teeth are cut directly into the gear, the entire gear must be replaced when they wear down. However, if the teeth are inserted separately and become worn, they can be replaced individually, which reduces replacement costs and allows for customization based on the application.
Gear teeth can be inserted either externally or internally. External teeth face outward from the gear's center, while internal teeth face toward the center. In a gear pair, the placement of teeth is crucial for determining rotational direction. If both gears in the pair have external teeth, they will rotate in opposite directions. To achieve the same rotational direction for both gears, an idler gear is placed between them, which reverses the rotation. If the gear pair consists of one gear with external teeth and the other with internal teeth, both gears will rotate in the same direction, eliminating the need for an idler gear and making this arrangement suitable for many applications.
Another key characteristic of gear teeth is the tooth profile, which is the cross-sectional shape of the tooth and affects speed and friction in the gear. There are several types of tooth profiles, with the most common being involute, trochoid, and cycloid. Involute gears have a curve that forms a locus shape, providing constant pressure and consistent performance, making it the most widely used profile for various applications. Trochoidal gears are often used in pumps, while cycloidal gears are employed in pressure blowers and clocks.
Gears are classified based on the positional relationship of their axes and gear pairs. The three main classifications are parallel axis, intersecting axis, and non-parallel/non-intersecting axis. In parallel axis configurations, the shafts are aligned parallel to each other. In intersecting axis configurations, the shafts are positioned at an angle or perpendicular to each other. Non-parallel and non-intersecting gears transmit rotational force through slippage between the gear tooth surfaces.
The term "parallel axis gear configuration" refers to power transmission between parallel shafts where the gears mesh to create rolling contact, achieving efficiency levels of 98% to 99.5%. In this setup, the gears are mounted on shafts aligned in the same plane, and the driven gear rotates in the opposite direction to the drive gear, which further enhances efficiency. This configuration provides high transmission of motion and rotation between the connected gears.
The types of gears used for the parallel gear configuration are double helical, helical, herringbone element, and spur gears, with spur and helical being the most commonly used. Spur gears are low cost and have a simple design but produce a great deal of noise and may not be ideal for large amounts of torque because of the one to one tooth contact.
For high torque applications, helical gears are the better choice. They have angled teeth that increase the ratio of contact and run quieter. The disadvantage of helical gears for parallel axis configurations is the axial thrust force produced by the helix form.
Gears with a parallel axis configuration offer excellent reliability, ease of maintenance, and a minimal number of components. This setup is the most common gear arrangement and includes a pinion and gears. Parallel gears are often categorized into configurations such as double increaser, reduction, triple increaser, or reduction gear.
The intersecting gear configuration features two axes that cross at a single point within the same plane. A crucial aspect of this configuration is ensuring the gears are correctly aligned with one another, with the mounting distance being a key design parameter. This distance involves aligning the locating surface on the back of one gear with the plane of the action apex. For optimal contact, the gear base cone apex, the mating pinion base cone apex, and the plane of apex must align precisely.
Intersecting gears are housed in a gear enclosure that supports the gear shafts and includes bores for their support. A crucial aspect of the housing is its ability to keep the gear and pinion axes aligned during rotation. The housing is designed to ensure that the pinion axis rotation is properly maintained.
The shafts for intersecting gears are positioned at an angle, allowing for adjustments in torque and speed based on their design. This configuration helps save space, enhances lubrication, and reduces stress on the gear teeth.
Bevel gears are typically used for applications where gears intersect at a right angle. Although they are more costly and transmit less torque compared to parallel shaft gear arrangements, they are designed with a cone shape and angled teeth along the sides of the cone. As one bevel gear turns, it drives another conical gear, altering the force and angle of power transmission.
When describing gears, it is typically understood that gears mesh securely to transmit power or force, with the teeth of one gear interlocking tightly with those of another. However, this is not the case for non-parallel and non-intersecting gears. In these configurations, rotational power is transmitted through relative slippage between the gear tooth surfaces. The rotating shafts of these gear pairs are aligned on a cross axis, resulting in lower rotary motion and reduced transmission power efficiency.
Similar to intersecting gears, non-parallel and non-intersecting gears are positioned at right angles to each other. These are referred to as skew bevel gears or spiral gears. Although they are perpendicular, they do not intersect. Non-parallel and non-intersecting configurations often involve helical gears with angled teeth that are placed perpendicularly to each other.
Another type of non-parallel and non-intersecting gear arrangement is the worm gear system, which includes a worm gear (or threaded shaft) and a spur gear. As the worm gear rotates, its threaded teeth move by a distance equal to the pitch of the screw threads. This rotation of the worm gear drives the spur gear.
The hypoid gear configuration, a type of non-parallel and non-intersecting gear setup, closely resembles intersecting gears. It features a pinion that meshes with a larger gear. As the pinion rotates at high speed, the larger gear rotates more slowly. The axes of the two gears are offset, which classifies them as non-parallel and non-intersecting gears.
When selecting gears for a specific application, several important factors should be considered. These include the material used in gear construction, surface treatments, the number and angle of teeth, and the type of lubricant.
A crucial aspect of gear production is selecting materials that balance strength, durability, and cost. The choice of materials depends on the specific requirements of the gear being manufactured. Additionally, it's important to find a combination of physical properties that meet the application’s needs while staying within the project’s budget.
Gears can be made from a variety of materials, including steel, brass, bronze, cast iron, ductile iron, aluminum, powdered metals, and various durable plastics. Among these, steel is the most commonly used due to its high strength-to-weight ratio, wear resistance, superior physical properties, and cost-effectiveness.
Gears can be made from a variety of materials, including steel, brass, bronze, cast iron, ductile iron, aluminum, powdered metals, and various durable plastics. Among these, steel is the most commonly used due to its high strength-to-weight ratio, wear resistance, superior physical properties, and cost-effectiveness.
Gears can be made from a variety of materials, including steel, brass, bronze, cast iron, ductile iron, aluminum, powdered metals, and various durable plastics. Among these, steel is the most commonly used due to its high strength-to-weight ratio, wear resistance, superior physical properties, and cost-effectiveness.
Cold rolled steel is an iron-based alloy with varying chemical compositions, typically featuring low carbon content. For gear manufacturing, low to medium carbon steel is commonly used. Cold rolled steel is first hot rolled and then subjected to additional processes to enhance its dimensional and mechanical properties. During cold rolling, heated steel is cooled and passed through rollers at room temperature under high pressure. This costly process achieves precise dimensional tolerances and an improved surface finish.
For gears, cold rolled steel is processed into sheets or plates of varying thicknesses suitable for different manufacturing methods. This process results in steel that is 20% stronger than hot rolled steel, making it ideal for high-stress applications. Cold rolled steel also provides a superior surface finish, allowing for the production of gears with a smooth, even, and shiny surface. Additionally, because cold rolled steel does not shrink after forming, gears made from it are dimensionally accurate and precise.
Hot rolled steel is not used for the manufacture of gears due to its rough scaly surface and oily finish. Although hot rolled steel costs less, has high strength, and is available in large quantities, it is unable to produce components that have tight tolerances and precision shapes, which automatically disqualifies it from gear production.
Tool steel alloys, which contain high levels of carbon and chromium along with varying amounts of molybdenum, cobalt, vanadium, and other key elements, are ideal for gear production. These alloys are well-suited for handling high loads, enduring impact at room temperature, and providing exceptional wear resistance. Tool steels are typically available in an annealed condition, which softens the material for easier machining or forming. Notable grades of tool steel include MTEK A2, MTEK A6, MTEK D2, MTEK D5, and MTEK H13.
Tool steel is widely used because of its hardness, wear resistance, toughness, and ability to withstand high temperatures. It is classified into seven categories: water-hardened, hot-worked, cold-worked, shock-resistant, mold steel, and special-purpose. Among these, cold-worked tool steel is the most commonly used for gear production.
The strength and carbide formation of tool steels result from their high carbon content, while nickel and cobalt contribute to their resistance to high temperatures. Carbide-forming metals such as chromium, molybdenum, tungsten, and vanadium enhance the hardness and wear resistance of tool steels. The carbon content in tool steels typically ranges from 0.7% to 1.5% by weight, with some grades containing up to 2.1%.
The manufacture of gears using tool steel includes cutting, forming, shearing, and stamping of sheets or plates of the metal.
For gears that require superior strength, iron alloys are the preferred material, with carbon steel being suitable for all types of gearing applications. Carbon steel is favored for its machinability, wear resistance, ability to be hardened, wide availability, and cost-effectiveness. Carbon steel is categorized into mild steel, medium carbon steel, and high carbon steel. Mild steel contains less than 0.3% carbon, while high carbon steel contains more than 0.6% carbon. All three types of carbon steel—mild, medium, and high—are used to manufacture spur gears, helical gears, gear racks, bevel gears, and worm gears.
Carbon steels can be hardened using induction or laser methods. Other steels, which have elements like aluminum, chromium, copper, and nickel added, are stronger and easier to machine. These alloyed steels offer better corrosion resistance compared to carbon steel and are used to manufacture the same types of gears as mild, medium, and high carbon steel alloys. The enhanced strength of these special alloyed steels allows gears to handle heavier loads and provides greater wear resistance.
Stainless steel is a specialized alloy containing 11% chromium and additional elements like nickel, manganese, silicon, phosphorus, sulfur, and nitrogen. It is classified into four main types: ferritic, austenitic, martensitic, and precipitation-hardened, each with unique properties and characteristics.
Ferritic stainless steels belong to the 400 series, whereas austenitic stainless steels are part of the 300 series. Among these, stainless steel alloy 304, with 18% chromium and 8% nickel, is the most widely used and popular. For gear production, stainless steel 303 is preferred due to its 17% chromium content and an added 1% sulfur, which enhances its machinability.
For applications requiring gears with enhanced corrosion protection, stainless steel 316 is used, which contains 16% chromium, 10% nickel, and 2% molybdenum. Gears typically manufactured from stainless steels 316 and 303 include spur gears, helical gears, and bevel gears.
Copper alloys are used to manufacture gears that need to withstand corrosive environments or require non-magnetic properties. Common copper alloys used for gears include brass, phosphor bronze, and aluminum bronze. Brass, an alloy of copper and zinc, alters the ductility of the material.
Brass with low zinc content is highly ductile, while high zinc content makes it less ductile. The copper in brass enhances machinability and provides antimicrobial properties. Brass gears, including spur gears and gear racks, are commonly used in low-load applications like instrument drives.
Phosphor bronze, an alloy of copper, tin, and phosphorus, benefits from the addition of tin, which strengthens the copper and improves its corrosion resistance. Phosphorus enhances the wear resistance and stiffness of the alloy. This makes phosphor bronze an excellent choice for high-friction components. It is particularly well-suited for worm gears, as it resists degradation when lubricated.
Another highly durable and wear-resistant copper alloy is aluminum bronze, which combines aluminum, iron, nickel, manganese, and copper. This alloy offers superior wear resistance compared to phosphor bronze, with added iron contributing to its enhanced durability. Its exceptional resistance makes it suitable for gears exposed to oxidation, salt water, and organic acids. Aluminum bronze can handle significantly larger loads than phosphor bronze, making it ideal for heavy-duty applications. It is commonly used to produce crossed-axis helical gears and worm wheels.
One advantage of bronze gears is their self-lubricating properties, which reduce the need for lubrication in worm gear assemblies. This feature simplifies maintenance and ensures smoother operation with reduced friction loss..
Aluminum alloy gears offer a high strength-to-weight ratio and are often used as an alternative to iron gears. Aluminum is approximately one-third the weight of steel alloys of the same size, making it advantageous for applications where weight is a concern. The passivation layer on aluminum provides protection against oxidation and corrosion. While aluminum alloy gears are more costly than carbon steel gears, they are less expensive than stainless steel gears and their ease of machining helps mitigate the higher cost.
The aluminum alloys commonly used in gear manufacturing are 2024, 6061, and 7075. Alloy 2024, which includes aluminum and copper, shares similarities with aluminum bronze, offering increased strength due to its copper content but reduced corrosion resistance. Alloy 7075, comprising zinc, magnesium, and aluminum, is known for its high strength and resistance to stress loading. Alloy 6061, made from aluminum, silicon, and magnesium, provides medium strength with good weldability and corrosion resistance.
All three of the alloys can be heat treated to improve their hardness. The gears that are made from aluminum include spur gears, helical gears, straight tooth bevel gears, and gear racks. Aluminum gears are used for moderate temperature applications since they begin to degrade at 204°C (400°F).
The plastics commonly used in gear production include polyacetal, polyphenylene sulfide, nylon, polyamide, polycarbonate, and polyurethane. These materials are chosen for their reliability and their resistance to heat, pressure, and corrosion.
While plastic gears can be manufactured from a single polymer, their properties and performance are significantly enhanced when different plastics are blended. Combining various plastics improves their resistance to tension, pressure, heat, and corrosion by leveraging the beneficial properties of each material.
One challenge with metal gears is the noise they generate during operation. Plastic gears, with their lower density, reduce resonance and create a quieter working environment. This sound-dampening quality makes plastic gears a highly desirable option for noise-sensitive applications.
Two key factors contributing to the popularity of plastic gears are their cost and effectiveness. The materials used to manufacture plastic gears are significantly cheaper than those for other gear types. Additionally, plastic gears offer excellent longevity, making them cost-effective over time due to their durable performance.
The primary choice for plastic gears is thermoplastic polyesters, which are more dimensionally stable than nylon. Nylon's tendency to absorb moisture can alter its properties and dimensions. Thermoplastic polyesters are favored for their dimensional stability and self-lubricating properties.
rewrite;The list of the benefits of plastic gears is very long and includes design flexibility, low cost, weight that is 15% to 20% less than steel, noise reduction, efficiency, accuracy, and durability. All of these characteristics are a necessity for gears that are normally constantly in motion and under stress. The efficiency of plastics is based on their low friction coefficient since less horsepower is required to operate them.
Understanding the various types of gears is crucial for selecting the right one to ensure effective force transmission in mechanical designs. Key factors in gear selection include its dimensions, such as module, number of teeth, angle, and face width.
A gearbox, or gear drive, is engineered to enhance torque from a drive motor, decrease the motor's speed, and alter the rotational direction of shafts. It connects to equipment or motors through couplings, belts, chains, or shafts. At the core of a gearbox are its gears, which work in pairs, engaging with one another to transmit power.
Gears play a crucial role in the effective operation of processes, equipment, machines, and complex mechanisms. They efficiently transfer motion, force, power, and torque between various components. Gears are categorized by type, class, and their specific functions, each designed to optimize performance. A clear understanding of the different gear types and their parameters is essential for effective planning and operation of equipment and systems.
Bevel gears are conical in shape and the teeth of this gear are placed around its conical surface. These gears are used in applications where there is a need for change around its axis of rotation. These gears transmit energy and power to the intersecting shafts by changing its rotation. The configuration angles that are required for bevel gears is usually 90 degrees though not always. Bevel gears are made with cast steel, plain carbon steel, and alloy steels. All have different characteristics and can be used according to their applications.
Crown bevel gears, also known as face gears and contrate gears, have helical teeth in the form of a spiral with a pitch angle that is equal to 90°. They mesh with other bevel gears, spur gears, and a pinion system to change rotary motion at a right angle. The projection of the teeth at a right angle to the plane of the wheel gives them the appearance of being a crown. Unlike conical bevel gears, crown bevel gears are cylindrical to be paired with other gears according to tooth design.
Crown gears are frequently used in applications where low noise is essential. They interact with a rack's interlocking cog, enabling the gear to move smoothly along the rack. While crown gears fell out of favor early in the 20th century, they have seen a resurgence due to the industry's shift towards energy-efficient and technologically advanced drives. The optimal integration of crown gears with motors, gearboxes, and control systems is leading to notable energy savings.
Crown gears are increasingly used due to the decentralization of drive technology, which is essential for the flexibility of modern industrial operations and the growing number of drives. The demand for efficient transmissions has led to a greater need for crown gearboxes to meet these requirements.
Hypoid bevel gears transmit rotational power between shafts positioned at right angles, making them ideal for heavy-duty truck drive trains. In a hypoid gear set, the smaller pinion gear shaft is offset from the larger crown gear shaft, so the gears do not intersect. This offset allows the pinion to have a larger diameter and a greater spiral angle, enhancing the contact area and tooth strength..
The spiral angle of hypoid bevel gears facilitates smooth meshing between the pinion and crown gears. This design increases tooth strength and contact area, allowing for a wider range of gear ratios and the transmission of higher torque. The benefits include reduced wear, lower friction, minimized energy loss, and enhanced efficiency.
Hypoid gear sets can distribute loads across multiple teeth simultaneously, with an average contact ratio of 2.2:1 to 2.9:1. This extended tooth-to-tooth contact allows hypoid gears to transmit higher torque compared to similarly sized bevel gears.
The advantages of hypoid gears have made them increasingly popular for speed reduction in power transmission and motion control systems. To accommodate this trend, manufacturers are designing motor flanges with hypoid gearboxes, enabling various motors to be mounted directly onto the gearbox housing.
Bevel gears are widely used across industries such as cement, beverage, food, mining, energy, and bulk handling. They are commonly employed in medium to large conveyors, crushing equipment, water treatment systems, and mixers.
Miter gears are employed for right-angle drives with a 1:1 gear ratio between intersecting shafts, particularly in applications requiring high efficiency. For proper meshing, miter gears must have the same number of teeth, pitch, and pressure angle. They can be used in sets of more than two gears. The axial thrust generated by miter gears necessitates the use of ball bearings or sleeve bearings to absorb this force and prevent separation. Miter gears are mounted at right angles, and hardened miter gears offer 50% more horsepower capacity and greater wear resistance compared to non-hardened miter gears.
Miter bevel gears are widely used for their ability to handle high speeds and torque loads smoothly and quietly. However, their use is limited to changing the direction of transmission because they cannot alter the transmission speed, as they have the same number of teeth. When miter bevel gears have spiral teeth, they are paired with right and left-handed configurations.
Spiral bevel gears have a curved angle of teeth placement. It is more angled and also provides gradual teeth to teeth contact than that of straight bevel gears. This gradual engagement of teeth greatly reduces the vibration and the noise that is produced even at high velocities. Spiral bevel gears are also available in left and right hand angled teeth. Spiral bevel gears are difficult to manufacture and have a structure. However they have greater tooth strength, smooth operations, and low noise during operations.
Straight bevel gears are the most commonly used gears in many industries, because the tooth design is so simple and can be manufactured easily. The teeth of straight bevel gears are designed so that when a perfectly matched straight bevel gear comes in contact, it fits with each other at once and not gradually. This adjustment of teeth produces lots of noise while working and also increases the stress that is produced on the gear’s teeth. All these reduce the lifespan and durability of the gear and machine.
Zerol gears are the combination of both spiral and straight gears. These gears have all the characteristics of both kinds of gears. Zerol gears have curved teeth that are placed straight on the conical surface. This means that zerol gears are used in the same applications as that of straight gears, however, zerol gears are much quieter and have less friction compared to straight gears. Additionally zerol gears are not placed at any angle therefore, these can rotate in any direction and are also available in both left hand and right hand design.
Internal gears are the ones which have teeth that are placed on the inside of the diameter of the cylinder. Internal gears are the best to use for high transmission of energy in small areas, low noise production, less vibration, low speed reduction, and low cost. Internal gears are also called ring gears and are ideally used for areas where there are space issues. The mating of external gears results in rotation in opposite direction and if there is mating of external and internal mesh then the rotation will be in the same direction.
The material used for manufacturing internal gears depends on its application. Usually, forged steel, cast and ground steel, aluminum, and plastic material are used.
A helical gear is a type of gear that has parallel configuration. This type of gear is also used for non parallel and non intersecting configuration. The teeth of helical gears are twisted around the cylindrical body and angled towards the gear face. Helical gears are designed with left and right hand angled teeth. Each gear pair is composed of a right and left hand gear of the same helix angle. This angled tooth design gives helical gear an advantage because it can mate with other gears differently than those of straight cut teeth. If the mated pair is perfectly matched to each other then the contact level between the corresponding teeth is at a maximum and at intervals, rather than the whole tooth engagement at once. This engagement will help in reducing the noise created from machines and also lower the impact on the teeth.
Some disadvantages of helical gears are that it may work with great efficiency but its capacity is quite less than that of spur gears. Along with that the tooth design of these gears is quite difficult to manufacture and also costs a lot. Single helical gears also create axial thrusts thus; there is a need for thrust bearing in the applications that use single helical gears. This necessity also increases the cost related issues of these gears. Helical gears are made of aluminum, bronze, steel, and nylon. Other subtypes of helical gears are:
Left handed and right handed helical gears that have the same twist angle are referred to as double helical gears, which transmit rotational motion between two parallel shafts. They have the same advantages as other helical gear, including strength and low resonance, with the added advantage of being able to cancel thrust forces with their combination of right and left hand twists. The unfortunate aspect of double helical gears is the extra amount of effort that is necessary to manufacture them.
Double helical gears and herringbone gears are the same type of gear but with slight difference between the gears, which is a groove that is in the center of double helical gears while the groove is absent from herringbone gears. The configuration of double helical gears with two helical gears at the same angle with opposing thrust forces enables them to annihilate each other's thrust forces to overcome axial thrust.
Herringbone gears are double helical gears that have adjoining gear teeth. As with double helical gears, the teeth on herringbone gears are right and left hand gear teeth that have the appearance of the letter V and are designed to cancel out their mutual thrust. Like most helical gears, herringbone gears operate quietly, smoothly, and at high speeds. One of their main characteristics, like most helical gears, is the engagement of multiple teeth during each rotation, which distributes the load and is the reason for their quiet operation.
The teeth of herringbone gears can be manufactured such that tooth tips align with opposite tooth tips or with the opposite gears tooth trough. They are manufactured in pairs and are more expensive than other helical gears due to their complex tooth profile. In some cases, two opposite hand helical gears that are adjacent with a milled center, flat groove. As with most gears, herringbone gears are mounted on a hub or shaft with a hub being cylindrical and placed on one or both sides of the gear.
Shaft mountings of herringbone gears include keyway, set screw, split, or simple bore. Of the four mounting types, keyway mountings can only be used with shafts that have a cutout while set screw, split, and simple bore mountings do not require a special type of shaft.
Screw gears are also a sub type of helical gears and they are used for non parallel and non intersecting configurations. Herringbone gears are employed as right hand and left hand pairs but screw gears are employed for the same hand pair. These types of gears are usually low capacity and low efficiency and cannot be used for high power applications.
Helical gears are widely used in industries like cement, beverage, food, mining, marine, energy, forest, and bulk material handling. Its applications are for medium to large conveyors, mixers, large pumps, water treatments, and crushers. Double helical gears and herringbone gears are used in mining, marine, and heavy industries. It is also used in milling, steam turbines, and ship propulsions.
Single helical gears have a single row of teeth that are cut at an angle to the axis of the gear along a spiral path in a single left hand or right hand helix. They are able to develop axial thrust and radial thrust with low power transmission. The common helix angle for single helical gears is between 15o and 45o since high helix angles cannot be used. Single helical gears mate slowly, which results in reduced vibrations, noise, and teeth wear. Like spur gears, single helical gears are used to transmit motion and power between parallel shafts. Unlike spur gears, single helical gears have to be used in pairs due to the angle of their teeth.
The versatility of single helical gears makes it possible to mount them parallel to each other or on shafts at right angles to each other, an arrangement that is similar to worm gear and shaft configurations. The gradual engagement and quick release of single helical gears eliminates the shock and jar that is found in spur gear teeth operating under heavy loads. Shaft support bearings for single helical gears have to be strong because of the end load that is produced by their use.
Different types of plastic gears are now widely used in the engineering industry for manufacturing gears. Plastic gears are becoming the first choice of many industries due to their wide range of applications and its availability to work in all types of configuration. Plastic gears are used in a parallel axis configuration such as helical cylindrical gears, double helical gears, and spur cylindrical gears. It is also available for non parallel configuration such as bevel gears, screw gears, and worm gears. Plastic is also used in gears that are used for special applications such as internal gears and rack and pinion gears.
A variety of plastic gears can be made according to the application and can be differentiated on the basis of shape and shaft position. Plastic material is melted and can be molded into any required shape. The material could be PVC, Teflon, or nylon.
Plastic gears are the best option in industries because these are noise dampening, less vibratory, manage the impact load, low cost, low weight, reduced coefficient of friction, absorbs shocks, low maintenance and protects the teeth from wear and tear by distributing the load. Along with all these advantages there are some disadvantages of using plastic gears. These gears have low capacity of load carrying, can be negatively affected by certain chemicals, high cost of initial molds and greater dimensional instability.
Plastic gears are widely used in cameras, toys, electronic equipment, wall clocks, projectors, speedometers and many other home appliances that use plastic gears in their working.
Rack and pinion is a gear pair and it consists of a gear rack and a gear that is cylindrical in shape known as pinion. The gear rack is a flat bar that has infinite radius and it also has straight teeth that are inserted on the surface of the bar. The configuration of these gears is dependent on the type of pinion gear with which these are mated. If it is mated with a spur gear then it is parallel and if it is mated with a helical gear then it is angled. Both these designs can be used in a rack. The rotational movement can be changed into linear one and linear can be changed into rotational one. One rack and pinion gear advantage is the design of this gear. It is also the simplest to manufacture and is also low in cost. But there are some limitations to this design in that the transmission of energy cannot continue in one direction for infinite time. The motion can be limited by the length of the rack, and a great space present between the mated pair which will create a lot of friction and stress on the teeth of the gear.
The material that is used in rack and pinion gears are aluminum and steel. This gives maximum strength to these gears.
Rack and pinion gears are commonly used in the automotive industry in steering systems and also in weighing scales.
Spur gears are the most common type of gear. They have a circular or cylindrical body with teeth that are cut straight and are aligned parallel to the gear shafts. Mated pairs of spur gears are placed in a parallel axis configuration for transmission of motion and power. The mating of spur gears depends on their application, since they can be mated with other spur gears, internal gears, or a planetary gear.
Spur gears are widely used because their tooth design is simple, allow for a high degree of precision, and are easy to manufacture. The drawbacks to spur gears is their inability to handle axial loads, high speed, and large loads. As with many forms of gears, spur gears create a great deal of noise when operating in high speed applications. Regardless of these complications, spur gears have a very high efficiency rating.
Spur gears are made from brass, steel, and plastics and are divided into external gears and internal gears.
The distinctive feature of external spur gears is the placement of their teeth on the external circumference of the gear with the teeth jutting out and away from the center of the gear. The teeth of an external gear are cut on the outside surface of the cylinder, pointing away from the center. During motion and transmission of power, the input and output shafts move smoothly in opposite directions as the external gear teeth mesh.
When external gears mesh, they have a narrow contact surface due to the convex pairing of the flanks of the teeth, which leads to high tooth loads, referred to as Hertzian contact stress, causing extensive wear on the gears and flanks of their teeth . When an external gear is pair with an internal gear, a convex or concave flank pairing occurs, which results in a larger contact area and lower tooth loads and reduced wear. The pairing results in higher torque transmission than would be possible between two external paired gears.
External gears are the most popular type of gear and considered to be the simplest gear system having straight teeth that are parallel to their axis. In all instances, external gears are used to transmit rotary motion between parallel shafts and have a small gear, or pinion, that drives a larger gear. The contact between the gears is noisy, which increases at high speeds. Since external gears are frictionless, they provide a smooth ride.
Unlike external gears, internal gear teeth point inward, toward the center of the cylinder. The teeth have the same shape as that of other spur gears with the differentiating factors being their location and their direction. The appearance of an internal gear is that of a smooth circle with teeth cut into the inner portion of the circumference of the circle. This view of internal gears has led to them being named ring gears due to their resemblance to a special form of ring.
The design of internal gears places the centers of their mating gears closer together than is possible with external gears, which makes them ideal for applications where space is a problem. Their increased area contact makes it possible for internal gears to produce stronger drive due to the increased area contact with less sliding. One of the most popular uses for internal gears is as part of planetary gear systems, also known as epicyclic gears, to serve as the support for the sun and its planets.
One of the benefits of internal gears is the protection they offer against the intrusion of dirt, dust, and other obstructions. The limited use of internal gears is due to their complexity and the high cost of manufacturing them.
The spur gears are widely used in many industries such as food, forest, unit handling, beverage, automotive, and energy. It has a variety of applications such as uses in clocks, washing machines, watering systems, small conveyors, package handling equipment, automotives, planetary gear sets, and many more.
Worm gears are also called cylindrical gears or screw shaped gears. It consists of a worm wheel and a worm or screw shaped gear. These gears are manufactured to work with non parallel and non intersecting configurations. The design and angle of these gears is such that the worm can make the wheels rotate but the wheels cannot change the rotation of the screw or worm. This mechanism works in machines that require self locking ability. These gears have a high gear ratio and capacity making them suitable for work in a quieter environment and producing less noise. Some disadvantages include low transmission power and a lot of friction that is produced during functioning. This friction requires lots of lubrication for these gears to run smoothly.
The material that is used for manufacturing worm gears is steel for the worm or the screw that is placed in between and bronze or cast iron for the gears. This combination gives a high speed of rotation to these gears.
Worm gears are used in food, beverage, automotive, forest, energy, and unit handling industries for small conveyors, package handling equipment, lifts, elevators, and farm machinery.
Differential gears are made up of two halves of an axle with a gear placed on the ends of each half, which are connected by a third gear to form three sides of a square. In some instances, a fourth gear is added to complete the square. To complete the set, a ring gear is added to the differential casing that holds the three or four core gears in place, which is connected to the drive shaft by a pinion to power the wheels.
This arrangement of gears is the most common form of differential gear set, is referred to as an open differential gear set, and is used to develop more complicated differential gear sets. It enables the axle of a vehicle to corner smoothly and is less expensive to produce than more complicated differential gears.
Although open differential gears are commonly used, they are the foundation for all forms of differential gears including locked, welded and spool, limited slip, torsen (torque sensing), active, and torque vectoring. Each of the different types of differentials are designed to control torque, slippage, and other factors related to differential gear performance.
The term industrial gears covers a wide range of gears that transfer power between systems, allow for a variety of speeds and loads, and achieve a fixed range of input speeds and loads. The list of industrial gears includes all of the gears described above each of which is included in a system, process, or special configuration.
The standards for industrial gears have been established by industries, applications, and regions of the country. Standards for gears in the United States are in compliance with the American Gear Manufacturing Association (AGMA), which assists in setting up the global standards of the International Standards Organization (ISO).
Industrial gearboxes enhance the output torque and alter motor speeds with a shaft of a motor linked to the gearbox. The gear ratio of the gearbox determines the output torque and speed depending on the arrangement of the gears. The designs of gearboxes vary according to the industry for which they are manufactured with the different industrial uses being agricultural, construction, mining, and equipment for automotive production. The various configurations of gearboxes are available individually or in combination depending on the application.
The most commonly used types of industrial gearboxes are helical, coaxial helical inline, bevel helical, skew bevel helical, worm reduction, and planetary, each of which is used to improve a company’s efficiency and industrial capacity. They are an essential component to the production of products and assisting in the maintenance of industrial systems.
There are several factors that distinguish nylon gears from traditional metal gears with their lubricity and noise reduction being two of their most outstanding qualities. Nylon is a strong engineering plastic with exceptional wear qualities and properties. It is often used for the manufacture of bearings and bushings due to its lubricity.
For certain applications, nylon is stronger than steel and lasts longer. There is a long list of different types of nylon, each of which has been engineered to meet the needs of different applications. As part of the research regarding the use of nylon, different polyamides have been developed, some with one monomer and others with two monomers with each having different properties. When two types of nylon are polymerized together, they form a copolymer that is identified with a dash between the numbers. The distinctions for nylons continues with new combinations being constantly developed.
Of the long list of nylons, the nylon that is used to manufacture gears is PA610 or nylon 610, which is tough, rigid, and heat resistant with low moisture absorption and resistance to UV, chemicals, wear, and zinc chloride solutions. Since it can be used for injection molding and extrusion, it is the ideal nylon for the manufacture of high precision gears used in a variety of climatic conditions.
Planetary gears, also known as epicyclic gears, are a multi-gear set that includes an internal gear, a central gear or sun, a planetary carrier, and one or more other gears known as planets. All of the gears in the set are spur gears, including the internal gear. The multiple gears in a planetary gear make it easy to adjust, change, and convert gear ratios. The engineering of the components provides stability due to the even distribution of mass and rotational stiffness.
The types of planetary gears are categorized by their performance, efficiency, and versatility with all types being able to change two inputs into a single output. They provide exceptional torque with proportional stiffness and little noise. The types of planetary gears include single stage, multi-stage, inline, offset, right angle, harmonic, simpson, Ravigneaux, and differential. These nine types are a small sampling of the many types of planetary gears and does not include ones that have been specially designed for unique applications.
There are an endless number of functions that planetary gears perform, which include speed reduction, increase torque, and sharing a load with multiple gears due to the even distribution of a load that makes planetary gears resistant to damage. Planetary gears are used in rugged applications because of the load distribution and their robust design that is able to handle high torque and reductions.
Rear end gears provide mechanical leverage that multiplies torque to help engines move machines. As the gear ratio gets higher, rear end gears provide more leverage to help with acceleration. The gear ratio of a rear end gear refers to the gear ratio between the driven gear or ring and the drive gear or pinion, which is calculated by dividing the number of teeth of the ring gear by the number of drive gear teeth.
The purpose of rear end gears is to ensure that a vehicle can handle different rotational speeds when turning corners and being reversed. Their structure includes bevel gears, spur gears, and planetary gears. A typical rear end gear set includes bevel gears, an axle, shafts, and a carrier with teeth that come in several varieties and are arranged into an epicyclic configuration that makes it possible to attach axles that turn at different speeds. These components are used to multiply the torque from the engine and transmission and assist in the operation of a machine or the movement of a vehicle.
The ratio of rear end gears can be explained with an understanding that higher ratios of rear end gears provide better acceleration or torque while lower gear ratios offer fuel economy and better top speeds. Rear end gears have exceptionally high performance when transmitting motion and force and offer high reliability and longevity.
Small gears turn very quickly with less force and are used to increase the force of other, larger gears. They rotate at a faster speed and require less force. The principle of gear transmission ratio is when two gears of different diameters mesh and rotate together, the gear with the larger diameter will rotate slower than the smaller gear. How the gears are arranged, small to large or large to small, determines the amount of speed that will be generated by their connecting.
To increase speed, a larger gear receives power from the motor. As it turns once, the speed of the smaller gear greatly increases because one turn of the larger gear makes the smaller gear turn multiple times and faster. In many cases, one turn of a larger gear can cause a smaller gear to turn four times faster.
If a small gear is providing the power to turn a larger gear, movement will be slower since multiple turns of the smaller gear produces one turn of the larger gear. This motion produces higher torque and force making it possible to slowly move large loans.
The relationship between large and small gears is mainly seen in spur gears with different diameters. Several small gears can be found in planetary gears and are used for the same principle of changing torque, power, and speed. In the case of planetary gears, the sun gear or central gear is normally larger than the planet gears and receives the power that is to be changed and transmitted.
Spline gears are rods, such as drive shafts, that have teeth to transfer torque between machine parts by meshing with the teeth on a mating piece internal spline shaft. They are like gears in that they have teeth along their exterior that lock in place with the teeth of their mated internal spline shaft. Spline gears are unlike gears in that they use all their teeth to transfer torque while gears transfer torque one tooth at a time. They mesh with an equal number of teeth with their mating piece.
The manufacture of spline gears takes several different forms and includes broaching, shaping, milling, hobbing, rolling, grinding, and extruding. The most common forms of spline gears are parallel key spline gears, involute splines that are related to involute gears, and serrations. Internal spline gears are made the same way as external spline shafts with the only exception being the use of hobbing due to accessibility problems.
Splined gears or shafts transfer torque using an externally splined shaft mated with an internal shaft with slots for the external shaft’s teeth. The driven shaft can be the internal or external one. Spline gears have their teeth built into the full length of the shaft, which makes them more efficient at preventing rotation and transmitting torque.
Sprockets are wheels with teeth or notches around their circumference that are able to engage chains or belts that have the same thickness and pitch. They have the appearance of gears but are not designed to mesh with one another. Sprockets are commonly seen on bicycles and motorcycles as the chain drive. They are made from steel and aluminum with steel being the more durable and long lasting.
The parts of sprockets include the number of their teeth, their pitch and outside diameters, and the pitch per tooth. Much like the diameter of gears, the pitch diameter is the diameter of a sprocket that is the circumference of the sprocket beneath its teeth while the outside diameter is the circumference at the end tips of the teeth. The pitch is the measurement of each tooth that needs to fit into the pins on a chain and is precision calculated.
Double duty sprockets have two teeth per pitch to advance a second set of teeth when one set wears out. Hunting tooth sprockets have an uneven number of teeth that change every time the sprocket rotates to save on tooth wear. Segmental rim sprockets make it possible to remove the rim of the sprocket without the need to disturb the chain. When higher torque is required, multiple strand sprockets are used that are capable of handling higher power such as being powered by a drive shaft.
Sprockets that are fitted to a shaft are pilot bore and taper bush. The common use for pilot bore sprockets is on industrial machinery. They have a cylindrical projection that is drilled to the size of the bore and are fixed to a shaft using grub screws, pins, or locking bushings. Taper bush sprockets have a split through the taper and flange for clamping on a shaft.
Gears are an industry essential that are used for the transmission of motion and power in clocks, instruments, machinery, vehicles, and industrial equipment. They are engineered to reduce or increase speed in motorized implements and change the direction of power smoothly and efficiently. Since their introduction thousands of years ago, gears have become an essential tool for the innovations and improvements of industry.
Made from highly durable materials, gears play a key role in the productivity of machines and the operations of manufacturing. Each type of gear has varied elements, characteristics, advantages, and properties that meet the requirements and specifications for motion or power transmission. The wide variety and number of gears makes it possible to find a gear for every application.
One of the main functions of gears is to change the rotation speed of power with engines being the most common example. Gears regulate power by their ratios with different sizes of gears used to increase or decrease transmitted power by their rotation.
During the transmission of power, gears intermesh with other gears without slipping and strongly retain their connections. The motor in a machine may not be designed to move a shaft directly and uses gears to transmit power to the shaft to power a tool.
Torque is the rotating force that is produced by motors and engines that is adjusted through the use of gears, gear sets, gearboxes, and gear assemblies. Smaller gears produce less torque while large gears produce higher amounts of torque. When a small gear is the drive gear to power a large gear, the amount of torque increases and speed decreases. Taken in reverse, when a large gear is the drive gear and a small gear is the powered gear, the amount of torque decreases and speed increases.
A common use for gears is the changing the direction of rotation or movement, which is completed by the specific design of gear pairs. The rotational direction of a motor is dependent on the rotation of a shaft with the direction of the rotation capable of being changed by the configuration of the gears.
Gearboxes are one of the most common uses of gears and are made up of an assortment of gear types contained in a housing. Gearboxes contain worm, bevel, helical, and spur gears that are engineered to change torque, speed, power, motion, and force. Gearboxes are a foundational part of motor driven vehicles and gas powered machinery.
A bevel gear is a toothed rotating machine element used to transfer mechanical energy or shaft power between shafts that are intersecting, either perpendicular or at an angle. This results in a change in the axis of rotation of the shaft power...
A gear is a particular kind of simple machine that controls the strength or direction of a force. A gear train is made up of multiple gears that are combined and connected by their teeth. These gear trains allow energy to move from...
A planetary gear is an epicyclic gear that consists of a central gear, referred to as the sun gear and serves as the input gear, which has three or more gears that rotate around it that are referred to as planets...
A plastic gear is a toothed wheel made up of engineering plastic materials that work with others to alter the relation between the speed of an engine and the speed of the driven parts. The engineering plastic materials used in manufacturing plastic gears can be...
A spur gear is a cylindrical toothed gear with teeth that are parallel to the shaft and is used to transfer mechanical motion and control speed, power, and torque between shafts. They are the most popular types of cylindrical gears and...
A worm gear is a staggered shaft gear that creates motion between shafts using threads that are cut into a cylindrical bar to provide speed reduction. The combination of a worm wheel and worm are the components of a worm gear...
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A lead screw is a kind of mechanical linear actuator that converts rotational motion into linear motion. Its operation relies on the sliding of the screw shaft and the nut threads with no ball bearings between them. The screw shaft and the nut are directly moving against each other on...
Powder metallurgy is a manufacturing process that produces precision and highly accurate parts by pressing powdered metals and alloys into a rigid die under extreme pressure. With the development and implementation of technological advances...
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