Gear Boxes 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 boxes and through the internal configuration of gears of gear boxes, 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 boxes 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 Boxes 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 Boxes are used in a variety of industries:

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

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

Bevel Gear Boxes

Bevel gear boxes are mainly used in right angle, low gear ratio applications, due to their shafts perpendicular arrangement to one another. Bevel gear boxes make it possible to change operating angles. Two different types of bevel gear boxes includes straight and spiral. Straight bevel gear boxes 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 boxes are typically constructed of cast iron, aluminum alloy or other steel materials.

Helical Gear Boxes

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

Spur Gear Boxes

Spur gear boxes are compact, cost-effective, efficient and readily available. Spur gear boxes are available in a 10:1 ratio per stage, made with straight teeth mounted on a parallel shaft. The noise level of spur gear boxes 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 boxes are widely used in applications requiring an increase or reduction in speed and high output torque. Spur gear boxes are typically constructed with metals such as steel or brass, and plastics such as nylon or polycarbonate.

Worm Gear Boxes

Worm gear boxes 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 boxes are typically constructed of aluminum, stainless steel and cast iron.

Planetary Gear Boxes

Planetary gear boxes are named so due to their resemblance of the solar system. Planetary gear boxes 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 boxes are used in applications requiring low backlash, compact size, high efficiency, resistance to shock, and high torque to weight ratio.

The price of gear boxes varies and is typically affected by size, accuracy specifications, backlash, and the gear ratio, as well as the specific manufacturer. Gear Boxes with a backlash in the range of 30 arc-minutes may cost as low as $500. The cost for gear boxes with a backlash value under 5 arc-minutes will cost more than gear boxes 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 Boxes
• High-Grade Gear Boxes
• Right-Angle Planetary Gear Boxes
• Rotating Output Flange Gear Boxes

All gear boxes 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 boxes 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.

Advantages of Gear Boxes

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

Disadvantages of Gear Boxes

• 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 boxes bi-directional?
A. Yes, planetary and spur gear boxes 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 boxes?
A. Anaheim Automation’s motors can be assembled with gear boxes to meet the necessary requirements of an application. Motors and gear boxes 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 boxes?
A. The lifetime of motors and gear boxes 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 boxes. 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 boxes would be used for right-angle applications?
A. A bevel and worm gear boxes 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 boxes with curved teeth are utilized in high performance, high speed applications. Worm gear boxes 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 boxes.

Q. Can gear boxes be backdriven?

A. Some gear boxes, such as spur gear boxes can be backdriven, while some, such as the worm gear boxes cannot be backdriven.

Q. How many planet gears are there in gear boxes?
A. The amount of planetary gears in gear boxes differs based on specific application requirements. Most planetary gear boxes 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 boxes and controls the speed at which gear boxes rotate. The configuration below illustrates the driver controlling the external motor, which is connected as the input shaft of gear boxes. As a result, when drivers are powered, motor shafts rotate inside gear boxes causing the output shaft of gear boxes to rotate. The output speed and torque is dependent on the internal configuration of the gearbox.

When considering gear boxes, 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 boxes 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 boxes. 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 boxes. 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 boxes. 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 boxes 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 Boxes" segment of this guide are bevel, helical, cycloid, spur and worm.

Backlash
Backlash is the angle in which the output shaft of gear boxes 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 boxes vary from one gearbox type to another, as well as differences between manufacturers. Most gear boxes are constructed from steel materials such as iron, aluminum and brass. Unlike other gearbox types, spur gear boxes 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 boxes are typically used in low-speed applications. These gear boxes can be noisy, and may have lower overall efficiency. Helical gear boxes are typically used in high-speed applications. These gear boxes are quieter in operation than straight gear teeth gear boxes, which may improve their overall efficiency.

Q. Are planetary and spur bevel gear box types bi-directional? A. Yes, planetary and spur bevel gear boxes are designed to be used for bi-directional operation. The direction the input shaft rotates and gear arrangement of the bevel gear box will determine the rotation of the output shaft. Q. Can Anaheim Automation’s motors be combined with a bevel gear box? A. Anaheim Automation’s motors can be assembled with a bevel gear box to meet the necessary requirements of an application. Motors and bevel gear boxes 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 bevel gear box? A. The lifetime of a motor and bevel gear box 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 bevel gear box. Anaheim Automation’s experienced Application Engineers are available to provide recommendations on the best products for your specific application criteria. Q. What type of bevel gear box would be used for right angle applications? A. A bevel and worm bevel gear boxes are mainly utilized in right angle applications. They offer high efficiency and low gear ratios. A straight bevel bevel gear box with straight cut teeth are utilized in slow speed applications, whereas spiral bevel bevel gear boxes with curved teeth are utilized in high performance, high speed applications. Worm bevel gear boxes 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 bevel gear box. Q. Can a bevel gear box be backdriven? A. Some bevel gear box types, such as a spur bevel gear box can be backdriven, while some, such as the worm bevel gear box cannot be backdriven. Q. How many planet gears are there in a bevel gear box? A. The amount of planetary gears in a bevel gear box differs based on specific application requirements. Most planetary bevel gear box 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.

When considering a bevel gear box, 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 bevel gear box 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 bevel gear box. 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 bevel gear box 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 bevel gear box. 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 bevel gear box 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 Bevel Gear Boxes segment of this guide are bevel, helical, cycloid, spur and worm. Backlash Backlash is the angle in which the output shaft of a bevel gear box 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.

There are many types of gear boxes manufactured throughout the world. One of the main differences between each individual gear box is their performance characteristics. Choosing from the various gear box types is application dependent. A gear box is available in many sizes, ratios, efficiencies and backlash characteristics. All of these design factors will affect the performance and cost of a gear box. There are several gear box types which are listed below: Bevel Gear Box A bevel gear box is mainly used in right angle, low gear ratio applications, due to their shafts perpendicular arrangement to one another. A bevel gear box makes it possible to change operating angles. Two different types of bevel gear boxes includes straight and spiral. A straight bevel gear box is used for slow speed applications, and have straight and tapered teeth. The spiral bevel gear box has curved and oblique teeth, and are used mainly for high-performance, high speed applications. A bevel gear box is typically constructed of cast iron, aluminum alloy or other steel materials. Helical Gear Box Unlike spur gears, gears on a helical gear box 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 box is compact, efficient and available in a 5:1 ratio per stage. A helical gear box can be used on non-parallel and perpendicular shafts. These gear box types are applicable in high horsepower and efficient applications. A helical gear box is typically constructed with cast iron, aluminum alloy or iron material. Spur Gear Box A spur gear box is compact, cost-effective, efficient and readily available. A spur gear boxe 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 box is relatively high due to colliding teeth of the gears. In comparison with a worm gear box, they are more expensive, noisier and have less shock capability. The spur gear box is widely used in applications requiring an increase or reduction in speed and high output torque. A spur gear box is typically constructed with metals such as steel or brass, and plastics such as nylon or polycarbonate. Worm Gear Box A worm gear box can handle high shock loads, and is low in noise and maintenance-free, but less efficient than other gear box types. It is also available in right angle configuration. The worm gear box 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 box is turned off, it is held in a locked position. A worm gear box is typically constructed of aluminum, stainless steel and cast iron. Planetary Gear Box A planetary gear box is named so due to their resemblance of the solar system. A planetary gear box 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 box is used in applications requiring low backlash, compact size, high efficiency, resistance to shock, and high torque to weight ratio.

Advantages of Gear Boxes • Low noise level • High efficiency • High reduction ratios • Increase/Decrease output torque • Increase/Decrease output speed • Durable Disadvantages of Gear Boxes • 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 boxes varies and is typically affected by size, accuracy specifications, backlash, and the gear ratio, as well as the specific manufacturer. Gear Boxes with a backlash in the range of 30 arc-minutes may cost as low as $500. The cost for gear boxes with a backlash value under 5 arc-minutes will cost more than gear boxes 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 Boxes • High-Grade Gear Boxes • Right-Angle Planetary Gear Boxes • Rotating Output Flange Gear Boxes

Q. Are planetary and spur gear boxes bi-directional? A. Yes, planetary and spur gear boxes 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 boxes? A. Anaheim Automation’s motors can be assembled with gear boxes to meet the necessary requirements of an application. Motors and gear boxes 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 boxes? A. The lifetime of motors and gear boxes 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 boxes. 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 boxes would be used for right-angle applications? A. A bevel and worm gear boxes 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 boxes with curved teeth are utilized in high performance, high speed applications. Worm gear boxes 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 boxes. Q. Can gear boxes be backdriven? A. Some gear boxes, such as spur gear boxes can be backdriven, while some, such as the worm gear boxes cannot be backdriven. Q. How many planet gears are there in gear boxes? A. The amount of planetary gears in gear boxes differs based on specific application requirements. Most planetary gear boxes 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 boxes and controls the speed at which gear boxes rotate. The configuration below illustrates the driver controlling the external motor, which is connected as the input shaft of gear boxes. As a result, when drivers are powered, motor shafts rotate inside gear boxes causing the output shaft of gear boxes to rotate. The output speed and torque is dependent on the internal configuration of the gearbox.

All gear boxes 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 boxes 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 boxes, 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 boxes 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 boxes. 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 boxes. 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 boxes. 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 boxes 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 Boxes segment of this guide are bevel, helical, cycloid, spur and worm. Backlash Backlash is the angle in which the output shaft of gear boxes 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 boxes vary from one gearbox type to another, as well as differences between manufacturers. Most gear boxes are constructed from steel materials such as iron, aluminum and brass. Unlike other gearbox types, spur gear boxes 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 boxes are typically used in low-speed applications. These gear boxes can be noisy, and may have lower overall efficiency. Helical gear boxes are typically used in high-speed applications. These gear boxes are quieter in operation than straight gear teeth gear boxes, which may improve their overall efficiency.

There are many types of gear boxes manufactured throughout the world. One of the main differences between individual gear boxes is their performance characteristics. Choosing from the various gearbox types is application dependent. Gear Boxes are available in many sizes, ratios, efficiencies and backlash characteristics. All of these design factors will affect the performance and cost of these gear boxes. There are several types of gear boxes which are listed below: Bevel Gear Boxes Bevel gear boxes are mainly used in right angle, low gear ratio applications, due to their shafts perpendicular arrangement to one another. Bevel gear boxes make it possible to change operating angles. Two different types of bevel gear boxes includes straight and spiral. Straight bevel gear boxes 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 boxes are typically constructed of cast iron, aluminum alloy or other steel materials. Helical Gear Boxes Unlike spur gears, gears on helical gear boxes are cut at angles which allow for gradual contact between the gear teeth. This design provides for a smooth and quiet operation. Helical gear boxes are compact, efficient and available in a 5:1 ratio per stage. Helical gear boxes can be used on non-parallel and perpendicular shafts. These types of gear boxes are applicable in high horsepower and efficient applications. Helical gear boxes are typically constructed with cast iron, aluminum alloy or iron material. Spur Gear Boxes Spur gear boxes are compact, cost-effective, efficient and readily available. Spur gear boxes are available in a 10:1 ratio per stage, made with straight teeth mounted on a parallel shaft. The noise level of spur gear boxes 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 boxes are widely used in applications requiring an increase or reduction in speed and high output torque. Spur gear boxes are typically constructed with metals such as steel or brass, and plastics such as nylon or polycarbonate. Worm Gear Boxes Worm gear boxes 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 boxes are typically constructed of aluminum, stainless steel and cast iron. Planetary Gear Boxes Planetary gear boxes are named so due to their resemblance of the solar system. Planetary gear boxes 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 boxes are used in applications requiring low backlash, compact size, high efficiency, resistance to shock, and high torque to weight ratio.

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

Q. Are planetary and spur gear box types bi-directional? A. Yes, planetary and spur gear boxes are designed to be used for bi-directional operation. The direction the input shaft rotates and gear arrangement of the planetary gear box will determine the rotation of the output shaft. Q. Can Anaheim Automation’s motors be combined with a planetary gear box? A. Anaheim Automation’s motors can be assembled with a planetary gear box to meet the necessary requirements of an application. Motors and planetary gear boxes 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 planetary gear box? A. The lifetime of a motor and planetary gear box 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 planetary gear box. Anaheim Automation’s experienced Application Engineers are available to provide recommendations on the best products for your specific application criteria. Q. What type of planetary gear box would be used for right angle applications? A. A bevel and worm planetary gear boxes are mainly utilized in right angle applications. They offer high efficiency and low gear ratios. A straight bevel planetary gear box with straight cut teeth are utilized in slow speed applications, whereas spiral bevel planetary gear boxes with curved teeth are utilized in high performance, high speed applications. Worm planetary gear boxes 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 planetary gear box. Q. Can a planetary gear box be backdriven? A. Some planetary gear box types, such as a spur gear box can be backdriven, while some, such as the worm gear box cannot be backdriven. Q. How many planet gears are there in a planetary gear box? A. The amount of planetary gears in a planetary gear box differs based on specific application requirements. Most planetary planetary gear box 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.

When considering a planetary gear box, 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 planetary gear box 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 planetary gear box. 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 planetary gear box 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 planetary gear box. 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 planetary gear box 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 Planetary Gear Boxes segment of this guide are bevel, helical, cycloid, spur and worm. Backlash Backlash is the angle in which the output shaft of a planetary gear box 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.

There are many types of gear boxes manufactured throughout the world. One of the main differences between each individual gear box is their performance characteristics. Choosing from the various gear box types is application dependent. A gear box is available in many sizes, ratios, efficiencies and backlash characteristics. All of these design factors will affect the performance and cost of a gear box. There are several gear box types which are listed below: Bevel Gear Box A bevel gear box is mainly used in right angle, low gear ratio applications, due to their shafts perpendicular arrangement to one another. A bevel gear box makes it possible to change operating angles. Two different types of bevel gear boxes includes straight and spiral. A straight bevel gear box is used for slow speed applications, and have straight and tapered teeth. The spiral bevel gear box has curved and oblique teeth, and are used mainly for high-performance, high speed applications. A bevel gear box is typically constructed of cast iron, aluminum alloy or other steel materials. Helical Gear Box Unlike spur gears, gears on a helical gear box 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 box is compact, efficient and available in a 5:1 ratio per stage. A helical gear box can be used on non-parallel and perpendicular shafts. These gear box types are applicable in high horsepower and efficient applications. A helical gear box is typically constructed with cast iron, aluminum alloy or iron material. Spur Gear Box A spur gear box is compact, cost-effective, efficient and readily available. A spur gear boxe 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 box is relatively high due to colliding teeth of the gears. In comparison with a worm gear box, they are more expensive, noisier and have less shock capability. The spur gear box is widely used in applications requiring an increase or reduction in speed and high output torque. A spur gear box is typically constructed with metals such as steel or brass, and plastics such as nylon or polycarbonate. Worm Gear Box A worm gear box can handle high shock loads, and is low in noise and maintenance-free, but less efficient than other gear box types. It is also available in right angle configuration. The worm gear box 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 box is turned off, it is held in a locked position. A worm gear box is typically constructed of aluminum, stainless steel and cast iron. Planetary Gear Box A planetary gear box is named so due to their resemblance of the solar system. A planetary gear box 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 box is used in applications requiring low backlash, compact size, high efficiency, resistance to shock, and high torque to weight ratio.

Advantages of Planetary Gear Boxes • Low noise level • High efficiency • High reduction ratios • Increase/Decrease output torque • Increase/Decrease output speed • Durable Disadvantages of Planetary Gear Boxes • 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 planetary gear boxes varies and is typically affected by size, accuracy specifications, backlash, and the gear ratio, as well as the specific manufacturer. Planetary Gear Boxes with a backlash in the range of 30 arc-minutes may cost as low as $500. The cost for planetary gear boxes with a backlash value under 5 arc-minutes will cost more than planetary gear boxes 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 Boxes • High-Grade Gear Boxes • Right-Angle Planetary Gear Boxes • Rotating Output Flange Gear Boxes

Q. Are planetary and spur gear boxes bi-directional? A. Yes, planetary and spur gear boxes 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 planetary gear boxes? A. Anaheim Automation’s motors can be assembled with planetary gear boxes to meet the necessary requirements of an application. Motors and planetary gear boxes 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 planetary gear boxes? A. The lifetime of motors and planetary gear boxes 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 planetary gear boxes. Anaheim Automation’s experienced Application Engineers are available to provide recommendations on the best products for your specific application criteria. Q. What types of planetary gear boxes would be used for right-angle applications? A. A bevel and worm planetary gear boxes 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 planetary gear boxes with curved teeth are utilized in high performance, high speed applications. Worm planetary gear boxes 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 planetary gear boxes. Q. Can planetary gear boxes be backdriven? A. Some planetary gear boxes, such as spur gear boxes can be backdriven, while some, such as the worm gear boxes cannot be backdriven. Q. How many planet gears are there in planetary gear boxes? A. The amount of planetary gears in planetary gear boxes differs based on specific application requirements. Most planetary gear boxes 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 planetary gear boxes and controls the speed at which planetary gear boxes rotate. The configuration below illustrates the driver controlling the external motor, which is connected as the input shaft of planetary gear boxes. As a result, when drivers are powered, motor shafts rotate inside planetary gear boxes causing the output shaft of planetary gear boxes to rotate. The output speed and torque is dependent on the internal configuration of the gearbox.

All gear boxes 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 boxes work relatively the same. Planetary gearboxes are 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 planetary gear boxes, 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 planetary gear boxes 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 planetary gear boxes. 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 planetary gear boxes. 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 planetary gear boxes. 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 planetary gear boxes 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 Planetary Gear Boxes segment of this guide are bevel, helical, cycloid, spur and worm. Backlash Backlash is the angle in which the output shaft of planetary gear boxes 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.