A gear reducer is a mechanical device utilized to increase the output torque or change the speed (RPM) of a motor. The motor’s shaft is attached to one end of the gear reducer and through the internal configuration of gears of a gear reducer, provides a given output torque and speed determined by the gear ratio.

Advancements in technology and the evolution of gears have made a more efficient and powerful gear reducer to be developed and manufactured at lower costs. Toothed gear systems have evolved from fixed axis gear systems to new and improved gears including helical, cycloid, spur, worm and planetary gear systems. A gear reducer is widely used in applications that require desired output speed (RPM), control the direction of rotation, and to translate torque or power from one input shaft to another.

A gear reducer is used in a variety of industries:

• Aerospace – In the aerospace industry, a gear reducer is used in space and air travel, i.e. Airplanes, missiles, space vehicles, space shuttles and engines.
• Agriculture – In the agriculture industry, a gear reducer is used for plowing, irrigation, pest and insect control, tractors and pumps.
• Automotive – In the automotive industry, a gear reducer is used in cars, helicopters, buses and motorcycles.
• Construction – In the construction industry, a gear reducer is used in heavy machinery such as cranes, forklifts, bulldozers and tractors.
• Food Processing – In the food processing industry, a gear reducer is used in conveyor systems, the processing of meat and vegetable products, and packaging applications.
• Marine Industry – In the marine industry, a gear reducer is used on boats and yatchs.
• Medical – In the medical industry, a gear reducer is used in surgical tables, patient beds, medical diagnostic machines, dental equipment and MRI and CAT scan machines.
• Power Plants – In power plants, a gear reducer is implemented in transformers, generators and turbines.

There are many types of gear reduceres manufactured throughout the world. One of the main differences between each individual gear reducer is their performance characteristics. Choosing from the various gear reducer types is application dependent. A gear reducer is available in many sizes, ratios, efficiencies and backlash characteristics. All of these design factors will affect the performance and cost of a gear reducer. There are several gear reducer types which are listed below:

Bevel Gear Reducer

A bevel gear reducer is mainly used in right angle, low gear ratio applications, due to their shafts perpendicular arrangement to one another. A bevel gear reducer makes it possible to change operating angles. Two different types of bevel gear reduceres includes straight and spiral. A straight bevel gear reducer is used for slow speed applications, and have straight and tapered teeth. The spiral bevel gear reducer has curved and oblique teeth, and are used mainly for high-performance, high speed applications. A bevel gear reducer is typically constructed of cast iron, aluminum alloy or other steel materials.

Helical Gear Reducer

Unlike spur gears, gears on a helical gear reducer is cut at angles which allow for gradual contact between the gear teeth. This design provides for a smooth and quiet operation. A helical gear reducer is compact, efficient and available in a 5:1 ratio per stage. A helical gear reducer can be used on non-parallel and perpendicular shafts. These gear reducer types are applicable in high horsepower and efficient applications. A helical gear reducer is typically constructed with cast iron, aluminum alloy or iron material.

Spur Gear Reducer

A spur gear reducer is compact, cost-effective, efficient and readily available. A spur gear reducere is available in a 10:1 ratio per stage, made with straight teeth mounted on a parallel shaft. The noise level of a spur gear reducer is relatively high due to colliding teeth of the gears. In comparison with a worm gear reducer, they are more expensive, noisier and have less shock capability. The spur gear reducer is widely used in applications requiring an increase or reduction in speed and high output torque. A spur gear reducer is typically constructed with metals such as steel or brass, and plastics such as nylon or polycarbonate.

Worm Gear Reducer

A worm gear reducer can handle high shock loads, and is low in noise and maintenance-free, but less efficient than other gear reducer types. It is also available in right angle configuration. The worm gear reducer configuration allows the worm to turn the gear with ease; however, the gear cannot turn the worm. The prevention of the gear to move the worm can be utilized as a braking system. When the gear reducer is turned off, it is held in a locked position. A worm gear reducer is typically constructed of aluminum, stainless steel and cast iron.

Planetary Gear Reducer

A planetary gear reducer is named so due to their resemblance of the solar system. A planetary gear reducer consists of three main components: sun gear, ring gear and two or more planet gears. The sun gear is the located in the center, the ring gear is the outermost gear, and the planet gears are the gears surrounding the sun gear inside the ring gear. A planetary gear reducer is used in applications requiring low backlash, compact size, high efficiency, resistance to shock, and high torque to weight ratio.

The price of a gear reducer varies and is typically affected by size, accuracy specifications, backlash, and the gear ratio, as well as the specific manufacturer. A gear reducer with a backlash in the range of 30 arc-minutes may cost as low as $500. The cost for a gear reducer with a backlash value under 5 arc-minutes will cost more than a gear reducer with high backlash values. Below is a list of gear reducer products offered by Anaheim Automation. Comprehensive specifications and pricing is available on our website at AnaheimAutomation.com, for each of the offered types:

• Economy Gear Reducer
• High-Grade Gear Reducer
• Right-Angle Planetary Gear Reducer
• Rotating Output Flange Gear Reducer

Each gear reducer works in a similar fashion. The directions the gears rotate are dependent on the input direction and orientation of the gears. For example, if the initial gear is rotating in a clockwise direction, the gear it engages will rotate counterclockwise. This continues down the line for multiple gears. The combination of different size gears and the number of teeth on each gear plays a significant role in the output torque and speed of the shaft. High gear ratios allow for more output torque and lower speeds, while lower gear ratios allow for higher output speed and less output torque.

A planetary gear reducer works relatively the same. A planetary gear reducer system is constructed with three main components: a central sun gear, a planet carrier (carrying one or more planet gears) and an annulus (an outer ring). The central sun gear is orbited by planet gears (of the same size) mounted to the planet carrier. The planet gears are meshed with the sun gear while the outer rings teeth mesh with the planet gears. There are several configurations for a gear reducer system. Typical configurations consist of three components: the input, the output and one stationary component.

For example: one possible configuration is the sun gear as the input, the annulus as the output and the planet carrier remaining stationary. In this configuration, the input shaft rotates the sun gear, the planet gears rotate on their own axes, simultaneously applying a torque to the rotating planet carrier that in turn applies torque to the output shaft (which in this case is the annulus). The rate at which the gears rotate (gear ratio) is determined by the number of teeth in each gear. The torque (power output) is determined by both the number of teeth and by which component in the planetary system is stationary.

Advantages of a Gear Reducer

• Low noise level
• High efficiency
• High reduction ratio
• Increase/Decrease output torque
• Increase/Decrease output speed
• Durable

Disadvantages of a Gear Reducer

• More costly than other drive systems
• Proper lubrication is necessary for smooth running
• Poorly cut teeth may result in excessive vibration and noise during operation
• Quality matters and adds to cost

Q. Are planetary and spur gear reducer types bi-directional?
A. Yes, planetary and spur gear reduceres are designed to be used for bi-directional operation. The direction the input shaft rotates and gear arrangement of the gear reducer will determine the rotation of the output shaft.

Q. Can Anaheim Automation’s motors be combined with a gear reducer?
A. Anaheim Automation’s motors can be assembled with a gear reducer to meet the necessary requirements of an application. Motors and gear reduceres can be purchased separately or be purchased as an assembled unit. Customization is available. Minimum purchase requirements and a Non-Cancellable/Non-Returnable agreement will apply.

Q. What is the lifetime of an Anaheim Automation motor and gear reducer?
A. The lifetime of a motor and gear reducer varies by user application. Certain factors determine the lifetime of a product, such as environment, radial loads (torque), duty cycle, and input power. All these factors play a role in the lifetime of a motor and gear reducer. Anaheim Automation’s experienced Application Engineers are available to provide recommendations on the best products for your specific application criteria.

Q. What type of gear reducer would be used for right angle applications?
A. A bevel and worm gear reduceres are mainly utilized in right angle applications. They offer high efficiency and low gear ratios. A straight bevel gear reducer with straight cut teeth are utilized in slow speed applications, whereas spiral bevel gear reduceres with curved teeth are utilized in high performance, high speed applications. Worm gear reduceres are also available with right angle configurations. They are able to sustain high shock loads, low in noise, maintenance-free but are less efficient than a bevel gear reducer.

Q. Can a gear reducer be backdriven?
A. Some gear reducer types, such as a spur gear reducer can be backdriven, while some, such as the worm gear reducer cannot be backdriven.

Q. How many planet gears are there in a gear reducer?
A. The amount of planetary gears in a gear reducer differs based on specific application requirements. Most planetary gear reducer types consist of two or more planetary gears.

Q. What is the difference between straight cut gears and helical gears?
A. Straight cut gears have straight and tapered teeth, and are used for low speed applications. Helical gears are cut at angles to allow gradual contact between the gear teeth. This allows for smooth and quiet operation. Helical gears are applicable in high horsepower and efficient applications.

The output of a motor (i.e. stepper, brushless, AC and brush motors) is used as the input of the gear reducer and controls the speed at which the gear reducer rotates. The configuration below illustrates the driver controlling the external motor, which is connected as the input shaft of the gear reducer. As a result, when the driver is powered, the motor shaft rotates inside the gear reducer causing the output shaft of the gear reducer to rotate. The output speed and torque is dependent on the internal configuration of the gear reducer.

When considering a gear reducer, many factors need to be considered to meet specific application requirements:

Gear Ratio
Gear ratios are defined as the correlation between the numbers of teeth of two different gears. Commonly, the number of teeth a gear has is proportional to its circumference. This means that the gear with a larger circumference will have more gear teeth; therefore the relationship between the circumferences of the two gears can also give an accurate gear ratio. For example, if one gear has 36 teeth while another gear has 12 teeth, the gear ratio would be 3:1.

Output Torque
Output torque of the gear reducer is dependent on the gear ratio used. To obtain a high output torque, a large gear ratio would be selected. Using a large gear ratio will lower the output shaft speed of the motor. Inversely, using a lower gear ratio, a smaller output torque value would be delivered into the system, with a greater motor speed at the output shaft of the gear reducer. This statement illustrates the relationship that both torque and speed are inversely proportional to one another.

Speed (RPM)
Speed is proportional to the gear ratio of the gear reducer system. For example, if the input gear has more teeth than the output gear, the result will be an increase in speed at the output shaft. On the other hand, having the reverse scenario with more gear teeth at the output compared to the input will result in a decrease of speed at the output shaft. In general, the output speed can be determined by dividing the input speed by the gear ratio. The higher the ratio the lower the output speed will be and vice versa.

Gear Arrangement
Gear arrangement is an ingenious engineering design that offers various benefits over the traditional fixed axis gear system design. The unique combination of both power transmission efficiency and compact size allows for a lower loss in efficiency of the gear reducer. The more efficient the gear arrangement, (i.e. spur, helical, planetary and worm) the more energy it will allow to be transmitted and converted into torque, rather than energy lost in heat.

Another application factor to be taken into account when selecting a gear reducer is load distribution. Since the load being transmitted is shared among multiple planets, the torque capacity is increased. The higher number of planets in a gear system will increase the load ability and enhance torque density. Gear arrangements improve stability and rotational stiffness because of a balanced system, but it is a complex and more costly design.

One example is a gear arrangement that is a traditional fixed axis gear system with a pinion driving a larger gear on an axis parallel to the shaft. Or, there may be a planetary gear design system with a sun gear (pinion) surrounded by more than one gear (planet gears) and is encompassed in an outer ring gear. The two systems are similar in ratio and volume, but the planetary gear design has three times the higher torque density and three times the stiffness due to the increased number of gear contacts. Fixed Axis Gear System:
   Volume = 1, Torque = 1, Stiffness = 1
Planetary Gear System:
   Volume =1, Torque = 3, Stiffness = 3
Other gear arrangements as mentioned in the "Types of Gear Reduceres" segment of this guide are bevel, helical, cycloid, spur and worm.

Backlash
Backlash is the angle in which the output shaft of a gear reducer can rotate without the input shaft moving, or the gap between the teeth of two adjacent gears. It is not necessary to consider backlash for applications which do not involve load reversals. However, in precision applications with load reversals like robotics, automation, CNC machines, etc., backlash is crucial for accuracy and positioning.

The physical components of a gear reducer varies from one gear reducer type to another, as well as differences between manufacturers. Most gear reducer types are constructed from steel materials such as iron, aluminum and brass. Unlike other gear reducer types, spur gear reduceres can also be made with plastics such as polycarbonate or nylon. Other than the raw materials used, the orientation of the gear teeth play a major role in the overall efficiency, torque and speed of the system. A straight gear teeth gear reducer is typically used in low-speed applications. This can cause the gear reducer to be noisy, and lower its overall efficiency. A helical gear reducer is typically used in high-speed applications. This type of gear reducer is quieter in operation than a straight gear teeth gear reducer, which may improve the overall efficiency.

Advantages of a Gear Reducer • Low noise level • High efficiency • High reduction ratios • Increase/Decrease output torque • Increase/Decrease output speed • Durable Disadvantages of a Gear Reducer • More costly than other drive systems • Proper lubrication is necessary for smooth running • Poorly cut teeth may result in excessive vibration and noise during operation • Quality matters and adds to cost

The price of a gear reducer varies and is typically affected by size, accuracy specifications, backlash, and the gear ratio, as well as the specific manufacturer. A gear reducer with a backlash in the range of 30 arc-minutes may cost as low as $500. The cost for a gear reducer with a backlash value under 5 arc-minutes will cost more than a gear reducer with high backlash values. Below is a list of gear reducer products offered by Anaheim Automation. Comprehensive specifications and pricing is available on our website at AnaheimAutomation.com, for each of the offered types: • Economy Gear Reducer • High-Grade Gear Reducer • Right-Angle Planetary Gear Reducer • Rotating Output Flange Gear Reducer

Q. Are planetary and spur gear reducer types bi-directional? A. Yes, planetary and spur gear reduceres are designed to be used for bi-directional operation. The direction the input shaft rotates and gear arrangement of the gear reducer will determine the rotation of the output shaft. Q. Can Anaheim Automation’s motors be combined with a gear reducer? A. Anaheim Automation’s motors can be assembled with a gear reducer to meet the necessary requirements of an application. Motors and gear reduceres can be purchased separately or be purchased as an assembled unit. Customization is available. Minimum purchase requirements and a Non-Cancellable/Non-Returnable agreement will apply. Q. What is the lifetime of an Anaheim Automation motor and gear reducer? A. The lifetime of a motor and gear reducer varies by user application. Certain factors determine the lifetime of a product, such as environment, radial loads (torque), duty cycle, and input power. All these factors play a role in the lifetime of a motor and gear reducer. Anaheim Automation’s experienced Application Engineers are available to provide recommendations on the best products for your specific application criteria. Q. What type of gear reducer would be used for right angle applications? A. A bevel and worm gear reduceres are mainly utilized in right angle applications. They offer high efficiency and low gear ratios. A straight bevel gear reducer with straight cut teeth are utilized in slow speed applications, whereas spiral bevel gear reduceres with curved teeth are utilized in high performance, high speed applications. Worm gear reduceres are also available with right angle configurations. They are able to sustain high shock loads, low in noise, maintenance-free but are less efficient than a bevel gear reducer. Q. Can a gear reducer be backdriven? A. Some gear reducer types, such as a spur gear reducer can be backdriven, while some, such as the worm gear reducer cannot be backdriven. Q. How many planet gears are there in a gear reducer? A. The amount of planetary gears in a gear reducer differs based on specific application requirements. Most planetary gear reducer types consist of two or more planetary gears. Q. What is the difference between straight cut gears and helical gears? A. Straight cut gears have straight and tapered teeth, and are used for low speed applications. Helical gears are cut at angles to allow gradual contact between the gear teeth. This allows for smooth and quiet operation. Helical gears are applicable in high horsepower and efficient applications.

Each gear reducer works in a similar fashion. The directions the gears rotate are dependent on the input direction and orientation of the gears. For example, if the initial gear is rotating in a clockwise direction, the gear it engages will rotate counterclockwise. This continues down the line for multiple gears. The combination of different size gears and the number of teeth on each gear plays a significant role in the output torque and speed of the shaft. High gear ratios allow for more output torque and lower speeds, while lower gear ratios allow for higher output speed and less output torque. A planetary gear reducer works relatively the same. A planetary gear reducer system is constructed with three main components: a central sun gear, a planet carrier (carrying one or more planet gears) and an annulus (an outer ring). The central sun gear is orbited by planet gears (of the same size) mounted to the planet carrier. The planet gears are meshed with the sun gear while the outer rings teeth mesh with the planet gears. There are several configurations for a gear reducer system. Typical configurations consist of three components: the input, the output and one stationary component. For example: one possible configuration is the sun gear as the input, the annulus as the output and the planet carrier remaining stationary. In this configuration, the input shaft rotates the sun gear, the planet gears rotate on their own axes, simultaneously applying a torque to the rotating planet carrier that in turn applies torque to the output shaft (which in this case is the annulus). The rate at which the gears rotate (gear ratio) is determined by the number of teeth in each gear. The torque (power output) is determined by both the number of teeth and by which component in the planetary system is stationary.

The output of a motor (i.e. stepper, brushless, AC and brush motors) is used as the input of the gear reducer and controls the speed at which the gear reducer rotates. The configuration below illustrates the driver controlling the external motor, which is connected as the input shaft of the gear reducer. As a result, when the driver is powered, the motor shaft rotates inside the gear reducer causing the output shaft of the gear reducer to rotate. The output speed and torque is dependent on the internal configuration of the gear reducer.

When considering a gear reducer, many factors need to be considered to meet specific application requirements: Gear Ratio Gear ratios are defined as the correlation between the numbers of teeth of two different gears. Commonly, the number of teeth a gear has is proportional to its circumference. This means that the gear with a larger circumference will have more gear teeth; therefore the relationship between the circumferences of the two gears can also give an accurate gear ratio. For example, if one gear has 36 teeth while another gear has 12 teeth, the gear ratio would be 3:1. Output Torque Output torque of the gear reducer is dependent on the gear ratio used. To obtain a high output torque, a large gear ratio would be selected. Using a large gear ratio will lower the output shaft speed of the motor. Inversely, using a lower gear ratio, a smaller output torque value would be delivered into the system, with a greater motor speed at the output shaft of the gear reducer. This statement illustrates the relationship that both torque and speed are inversely proportional to one another. Speed (RPM) Speed is proportional to the gear ratio of the gear reducer system. For example, if the input gear has more teeth than the output gear, the result will be an increase in speed at the output shaft. On the other hand, having the reverse scenario with more gear teeth at the output compared to the input will result in a decrease of speed at the output shaft. In general, the output speed can be determined by dividing the input speed by the gear ratio. The higher the ratio the lower the output speed will be and vice versa. Gear Arrangement Gear arrangement is an ingenious engineering design that offers various benefits over the traditional fixed axis gear system design. The unique combination of both power transmission efficiency and compact size allows for a lower loss in efficiency of the gear reducer. The more efficient the gear arrangement, (i.e. spur, helical, planetary and worm) the more energy it will allow to be transmitted and converted into torque, rather than energy lost in heat. Another application factor to be taken into account when selecting a gear reducer is load distribution. Since the load being transmitted is shared among multiple planets, the torque capacity is increased. The higher number of planets in a gear system will increase the load ability and enhance torque density. Gear arrangements improve stability and rotational stiffness because of a balanced system, but it is a complex and more costly design. One example is a gear arrangement that is a traditional fixed axis gear system with a pinion driving a larger gear on an axis parallel to the shaft. Or, there may be a planetary gear design system with a sun gear (pinion) surrounded by more than one gear (planet gears) and is encompassed in an outer ring gear. The two systems are similar in ratio and volume, but the planetary gear design has three times the higher torque density and three times the stiffness due to the increased number of gear contacts. Fixed Axis Gear System: Volume = 1, Torque = 1, Stiffness = 1 Planetary Gear System: Volume =1, Torque = 3, Stiffness = 3 Other gear arrangements as mentioned in the Types of Gear Reduceres segment of this guide are bevel, helical, cycloid, spur and worm. Backlash Backlash is the angle in which the output shaft of a gear reducer can rotate without the input shaft moving, or the gap between the teeth of two adjacent gears. It is not necessary to consider backlash for applications which do not involve load reversals. However, in precision applications with load reversals like robotics, automation, CNC machines, etc., backlash is crucial for accuracy and positioning.

The physical components of a gear reducer varies from one gear reducer type to another, as well as differences between manufacturers. Most gear reducer types are constructed from steel materials such as iron, aluminum and brass. Unlike other gear reducer types, spur gear reduceres can also be made with plastics such as polycarbonate or nylon. Other than the raw materials used, the orientation of the gear teeth play a major role in the overall efficiency, torque and speed of the system. A straight gear teeth gear reducer is typically used in low-speed applications. This can cause the gear reducer to be noisy, and lower its overall efficiency. A helical gear reducer is typically used in high-speed applications. This type of gear reducer is quieter in operation than a straight gear teeth gear reducer, which may improve the overall efficiency.

There are many types of gear reducers manufactured throughout the world. One of the main differences between each individual gear reducer is their performance characteristics. Choosing from the various gear reducer types is application dependent. A gear reducer is available in many sizes, ratios, efficiencies and backlash characteristics. All of these design factors will affect the performance and cost of a gear reducer. There are several gear reducer types which are listed below: Bevel Gear Reducer A bevel gear reducer is mainly used in right angle, low gear ratio applications, due to their shafts perpendicular arrangement to one another. A bevel gear reducer makes it possible to change operating angles. Two different types of bevel gear reducers includes straight and spiral. A straight bevel gear reducer is used for slow speed applications, and have straight and tapered teeth. The spiral bevel gear reducer has curved and oblique teeth, and are used mainly for high-performance, high speed applications. A bevel gear reducer is typically constructed of cast iron, aluminum alloy or other steel materials. Helical Gear Reducer Unlike spur gears, gears on a helical gear reducer is cut at angles which allow for gradual contact between the gear teeth. This design provides for a smooth and quiet operation. A helical gear reducer is compact, efficient and available in a 5:1 ratio per stage. A helical gear reducer can be used on non-parallel and perpendicular shafts. These gear reducer types are applicable in high horsepower and efficient applications. A helical gear reducer is typically constructed with cast iron, aluminum alloy or iron material. Spur Gear Reducer A spur gear reducer is compact, cost-effective, efficient and readily available. A spur gear reducere is available in a 10:1 ratio per stage, made with straight teeth mounted on a parallel shaft. The noise level of a spur gear reducer is relatively high due to colliding teeth of the gears. In comparison with a worm gear reducer, they are more expensive, noisier and have less shock capability. The spur gear reducer is widely used in applications requiring an increase or reduction in speed and high output torque. A spur gear reducer is typically constructed with metals such as steel or brass, and plastics such as nylon or polycarbonate. Worm Gear Reducer A worm gear reducer can handle high shock loads, and is low in noise and maintenance-free, but less efficient than other gear reducer types. It is also available in right angle configuration. The worm gear reducer configuration allows the worm to turn the gear with ease; however, the gear cannot turn the worm. The prevention of the gear to move the worm can be utilized as a braking system. When the gear reducer is turned off, it is held in a locked position. A worm gear reducer is typically constructed of aluminum, stainless steel and cast iron. Planetary Gear Reducer A planetary gear reducer is named so due to their resemblance of the solar system. A planetary gear reducer consists of three main components: sun gear, ring gear and two or more planet gears. The sun gear is the located in the center, the ring gear is the outermost gear, and the planet gears are the gears surrounding the sun gear inside the ring gear. A planetary gear reducer is used in applications requiring low backlash, compact size, high efficiency, resistance to shock, and high torque to weight ratio.

A gear reducer is a mechanical device utilized to increase the output torque or change the speed (RPM) of a motor. The motor’s shaft is attached to one end of the gear reducer and through the internal configuration of gears of a gear reducer, provides a given output torque and speed determined by the gear ratio.

Advancements in technology and the evolution of gears have made a more efficient and powerful gear reducer to be developed and manufactured at lower costs. Toothed gear systems have evolved from fixed axis gear systems to new and improved gears including helical, cycloid, spur, worm and planetary gear systems. A gear reducer is widely used in applications that require desired output speed (RPM), control the direction of rotation, and to translate torque or power from one input shaft to another. A gear reducer is used in a variety of industries: • Aerospace – In the aerospace industry, a gear reducer is used in space and air travel, i.e. airplanes, missiles, space vehicles, space shuttles and engines. • Agriculture – In the agriculture industry, a gear reducer is used for plowing, irrigation, pest and insect control, tractors and pumps. • Automotive – In the automotive industry, a gear reducer is used in cars, helicopters, buses and motorcycles. • Construction – In the construction industry, a gear reducer is used in heavy machinery such as cranes, forklifts, bulldozers and tractors. • Food Processing – In the food processing industry, a gear reducer is used in conveyor systems, the processing of meat and vegetable products, and packaging applications. • Marine Industry – In the marine industry, a gear reducer is used on boats and yatchs. • Medical – In the medical industry, a gear reducer is used in surgical tables, patient beds, medical diagnostic machines, dental equipment and MRI and CAT scan machines. • Power Plants – In power plants, a gear reducer is implemented in transformers, generators and turbines.

Advantages of Gear Reducers • Low noise level • High efficiency • High reduction ratios • Increase/Decrease output torque • Increase/Decrease output speed • Durable Disadvantages of Gear Reducers • More costly than other drive systems • Proper lubrication is necessary for smooth running • Poorly cut teeth may result in excessive vibration and noise during operation • Quality matters and adds to cost

The price of gear reducers varies and is typically affected by size, accuracy specifications, backlash, and the gear ratio, as well as the specific manufacturer. Gear Reducers with a backlash in the range of 30 arc-minutes may cost as low as $500. The cost for gear reducers with a backlash value under 5 arc-minutes will cost more than gear reducers with high backlash values. Below is a list of gearbox products offered by Anaheim Automation. Comprehensive specifications and pricing is available on our website at AnaheimAutomation.com, for each of the offered types: • Economy Gear Reducers • High-Grade Gear Reducers • Right-Angle Planetary Gear Reducers • Rotating Output Flange Gear Reducers

Q. Are planetary and spur gear reducers bi-directional? A. Yes, planetary and spur gear reducers are designed to be used for bi-directional operation. The direction the input shaft rotates and gear arrangement of the gearbox will determine the rotation of the output shaft. Q. Can Anaheim Automation’s motors be combined with gear reducers? A. Anaheim Automation’s motors can be assembled with gear reducers to meet the necessary requirements of an application. Motors and gear reducers can be purchased separately or be purchased as an assembled unit. Customization is available. Minimum purchase requirements and a Non-Cancellable/Non-Returnable agreement will apply. Q. What is the lifetime of Anaheim Automation’s motors and gear reducers? A. The lifetime of motors and gear reducers varies by user application. Certain factors determine the lifetime of a product, such as environment, radial loads (torque), duty cycle, and input power. All these factors play a role in the lifetime of motors and gear reducers. Anaheim Automation’s experienced Application Engineers are available to provide recommendations on the best products for your specific application criteria. Q. What types of gear reducers would be used for right-angle applications? A. A bevel and worm gear reducers are mainly utilized in right angle applications. They offer high efficiency and low gear ratios. A straight bevel gearbox with straight cut teeth are utilized in slow speed applications, whereas spiral bevel gear reducers with curved teeth are utilized in high performance, high speed applications. Worm gear reducers are also available with right angle configurations. They are able to sustain high shock loads, low in noise, maintenance-free but are less efficient than bevel gear reducers. Q. Can gear reducers be backdriven? A. Some gear reducers, such as spur gear reducers can be backdriven, while some, such as the worm gear reducers cannot be backdriven. Q. How many planet gears are there in gear reducers? A. The amount of planetary gears in gear reducers differs based on specific application requirements. Most planetary gear reducers consist of two or more planetary gears. Q. What is the difference between straight cut gears and helical gears? A. Straight cut gears have straight and tapered teeth, and are used for low speed applications. Helical gears are cut at angles to allow gradual contact between the gear teeth. This allows for smooth and quiet operation. Helical gears are applicable in high horsepower and efficient applications.

The output of a motor (i.e. stepper, brushless, AC and brush motors) is used as the input of gear reducers and controls the speed at which gear reducers rotate. The configuration below illustrates the driver controlling the external motor, which is connected as the input shaft of gear reducers. As a result, when drivers are powered, motor shafts rotate inside gear reducers causing the output shaft of gear reducers to rotate. The output speed and torque is dependent on the internal configuration of the gearbox.

All gear reducers work in a similar fashion. The directions the gears rotate are dependent on the input direction and orientation of the gears. For example, if the initial gear is rotating in a clockwise direction, the gear it engages will rotate counterclockwise. This continues down the line for multiple gears. The combination of different size gears and the number of teeth on each gear plays a significant role in the output torque and speed of the shaft. High gear ratios allow for more output torque and lower speeds, while lower gear ratios allow for higher output speed and less output torque. Planetary gear reducers work relatively the same. A planetary gearbox system is constructed with three main components: a central sun gear, a planet carrier (carrying one or more planet gears) and an annulus (an outer ring). The central sun gear is orbited by planet gears (of the same size) mounted to the planet carrier. The planet gears are meshed with the sun gear while the outer rings teeth mesh with the planet gears. There are several configurations for a gearbox system. Typical configurations consist of three components: the input, the output and one stationary component. For example: one possible configuration is the sun gear as the input, the annulus as the output and the planet carrier remaining stationary. In this configuration, the input shaft rotates the sun gear, the planet gears rotate on their own axes, simultaneously applying a torque to the rotating planet carrier that in turn applies torque to the output shaft (which in this case is the annulus). The rate at which the gears rotate (gear ratio) is determined by the number of teeth in each gear. The torque (power output) is determined by both the number of teeth and by which component in the planetary system is stationary.

When considering gear reducers, many factors need to be considered to meet specific application requirements: Gear Ratio Gear ratios are defined as the correlation between the numbers of teeth of two different gears. Commonly, the number of teeth a gear has is proportional to its circumference. This means that the gear with a larger circumference will have more gear teeth; therefore the relationship between the circumferences of the two gears can also give an accurate gear ratio. For example, if one gear has 36 teeth while another gear has 12 teeth, the gear ratio would be 3:1. Output Torque Output torque of gear reducers is dependent on the gear ratio used. To obtain a high output torque, a large gear ratio would be selected. Using a large gear ratio will lower the output shaft speed of the motor. Inversely, using a lower gear ratio, a smaller output torque value would be delivered into the system, with a greater motor speed at the output shaft of the gear reducers. This statement illustrates the relationship that both torque and speed are inversely proportional to one another. Speed (RPM) Speed is proportional to the gear ratio of gear reducers. For example, if the input gear has more teeth than the output gear, the result will be an increase in speed at the output shaft. On the other hand, having the reverse scenario with more gear teeth at the output compared to the input will result in a decrease of speed at the output shaft. In general, the output speed can be determined by dividing the input speed by the gear ratio. The higher the ratio the lower the output speed will be and vice versa. Gear Arrangement Gear arrangement is an ingenious engineering design that offers various benefits over the traditional fixed axis gear system design. The unique combination of both power transmission efficiency and compact size allows for a lower loss in efficiency of gear reducers. The more efficient the gear arrangement, (i.e. spur, helical, planetary and worm) the more energy it will allow to be transmitted and converted into torque, rather than energy lost in heat. Another application factor to be taken into account when selecting gear reducers is load distribution. Since the load being transmitted is shared among multiple planets, the torque capacity is increased. The higher number of planets in a gear system will increase the load ability and enhance torque density. Gear arrangements improve stability and rotational stiffness because of a balanced system, but it is a complex and more costly design. One example is a gear arrangement that is a traditional fixed axis gear system with a pinion driving a larger gear on an axis parallel to the shaft. Or, there may be a planetary gear design system with a sun gear (pinion) surrounded by more than one gear (planet gears) and is encompassed in an outer ring gear. The two systems are similar in ratio and volume, but the planetary gear design has three times the higher torque density and three times the stiffness due to the increased number of gear contacts. Fixed Axis Gear System: Volume = 1, Torque = 1, Stiffness = 1 Planetary Gear System: Volume =1, Torque = 3, Stiffness = 3 Other gear arrangements as mentioned in the Types of Gear Reducers segment of this guide are bevel, helical, cycloid, spur and worm. Backlash Backlash is the angle in which the output shaft of gear reducers can rotate without the input shaft moving, or the gap between the teeth of two adjacent gears. It is not necessary to consider backlash for applications which do not involve load reversals. However, in precision applications with load reversals like robotics, automation, CNC machines, etc., backlash is crucial for accuracy and positioning.

The physical components of gear reducers vary from one gearbox type to another, as well as differences between manufacturers. Most gear reducers are constructed from steel materials such as iron, aluminum and brass. Unlike other gearbox types, spur gear reducers can also be made with plastics such as polycarbonate or nylon. Other than the raw materials used, the orientation of the gear teeth play a major role in the overall efficiency, torque and speed of the system. Straight gear teeth gear reducers are typically used in low-speed applications. These gear reducers can be noisy, and may have lower overall efficiency. Helical gear reducers are typically used in high-speed applications. These gear reducers are quieter in operation than straight gear teeth gear reducers, which may improve their overall efficiency.

There are many types of gear reducers manufactured throughout the world. One of the main differences between individual gear reducers is their performance characteristics. Choosing from the various gearbox types is application dependent. Gear Reducers are available in many sizes, ratios, efficiencies and backlash characteristics. All of these design factors will affect the performance and cost of these gear reducers. There are several types of gear reducers which are listed below: Bevel Gear Reducers Bevel gear reducers are mainly used in right angle, low gear ratio applications, due to their shafts perpendicular arrangement to one another. Bevel gear reducers make it possible to change operating angles. Two different types of bevel gear reducers includes straight and spiral. Straight bevel gear reducers are used for slow speed applications, and have straight and tapered teeth. The spiral bevel gearbox has curved and oblique teeth, and are used mainly for high-performance, high speed applications. Bevel gear reducers are typically constructed of cast iron, aluminum alloy or other steel materials. Helical Gear Reducers Unlike spur gears, gears on helical gear reducers are cut at angles which allow for gradual contact between the gear teeth. This design provides for a smooth and quiet operation. Helical gear reducers are compact, efficient and available in a 5:1 ratio per stage. Helical gear reducers can be used on non-parallel and perpendicular shafts. These types of gear reducers are applicable in high horsepower and efficient applications. Helical gear reducers are typically constructed with cast iron, aluminum alloy or iron material. Spur Gear Reducers Spur gear reducers are compact, cost-effective, efficient and readily available. Spur gear reducers are available in a 10:1 ratio per stage, made with straight teeth mounted on a parallel shaft. The noise level of spur gear reducers is relatively high due to colliding teeth of the gears. In comparison with a worm gearbox, they are more expensive, noisier and have less shock capability. Spur gear reducers are widely used in applications requiring an increase or reduction in speed and high output torque. Spur gear reducers are typically constructed with metals such as steel or brass, and plastics such as nylon or polycarbonate. Worm Gear Reducers Worm gear reducers can handle high shock loads, and are low in noise and maintenance-free, but are less efficient than other gearbox types. They are also available in right angle configuration. The worm gearbox configuration allows the worm to turn the gear with ease; however, the gear cannot turn the worm. The prevention of the gear to move the worm can be utilized as a braking system. When the gearbox is turned off, it is held in a locked position. Worm gear reducers are typically constructed of aluminum, stainless steel and cast iron. Planetary Gear Reducers Planetary gear reducers are named so due to their resemblance of the solar system. Planetary gear reducers consist of three main components: sun gear, ring gear and two or more planet gears. The sun gear is the located in the center, the ring gear is the outermost gear, and the planet gears are the gears surrounding the sun gear inside the ring gear. Planetary gear reducers are used in applications requiring low backlash, compact size, high efficiency, resistance to shock, and high torque to weight ratio.

Gear Reducers are mechanical devices utilized to increase the output torque or change the speed (RPM) of a motor. Motor shafts are attached to one end of the gear reducerses and through the internal configuration of gears of gear reducers, providing a given output torque and speed determined by the gear ratio.

Advancements in technology and the evolution of gears have made more efficient and powerful gear reducers to be developed and manufactured at lower costs. Toothed gear systems have evolved from fixed axis gear systems to new and improved gears including helical, cycloid, spur, worm and planetary gear systems. Gear Reducers are widely used in applications that require desired output speed (RPM), control the direction of rotation, and to translate torque or power from one input shaft to another. Gear Reducers are used in a variety of industries: • Aerospace – In the aerospace industry, gear reducers are used in space and air travel, i.e. airplanes, missiles, space vehicles, space shuttles and engines. • Agriculture – In the agriculture industry, gear reducers are used for plowing, irrigation, pest and insect control, tractors and pumps. • Automotive – In the automotive industry, gear reducers are used in cars, helicopters, buses and motorcycles. • Construction – In the construction industry, gear reducers are used in heavy machinery such as cranes, forklifts, bulldozers and tractors. • Food Processing – In the food processing industry, gear reducers are used in conveyor systems, the processing of meat and vegetable products, and packaging applications. • Marine Industry – In the marine industry, gear reducers are used on boats and yatchs. • Medical – In the medical industry, gear reducers are used in surgical tables, patient beds, medical diagnostic machines, dental equipment and MRI and CAT scan machines. • Power Plants – In power plants, gear reducers are implemented in transformers, generators and turbines.

Advantages of a Planetary Gear Reducer • Low noise level • High efficiency • High reduction ratios • Increase/Decrease output torque • Increase/Decrease output speed • Durable Disadvantages of a Planetary Gear Reducer • More costly than other drive systems • Proper lubrication is necessary for smooth running • Poorly cut teeth may result in excessive vibration and noise during operation • Quality matters and adds to cost

The price of a planetary gear reducer varies and is typically affected by size, accuracy specifications, backlash, and the gear ratio, as well as the specific manufacturer. A planetary gear reducer with a backlash in the range of 30 arc-minutes may cost as low as $500. The cost for a planetary gear reducer with a backlash value under 5 arc-minutes will cost more than a planetary gear reducer with high backlash values. Below is a list of planetary gear reducer products offered by Anaheim Automation. Comprehensive specifications and pricing is available on our website at AnaheimAutomation.com, for each of the offered types: • Economy Planetary Gear Reducer • High-Grade Planetary Gear Reducer • Right-Angle Planetary Planetary Gear Reducer • Rotating Output Flange Planetary Gear Reducer