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Why are harmonic drives used in robotics?
Harmonic drives were once popular for robot arms, because they provide huge gear reductions in a small space.
What is the purpose of a harmonic drive?
Harmonic Drive developed a unique gear tooth profile that optimizes the tooth engagement. This tooth profile (the “S tooth”) enables up to 30% of the total number of teeth to be engaged simultaneously. Additionally the large tooth root radius increases the tooth strength compared with an involute tooth.
What are the two advantages of harmonic gears?
Compared to classical toothed gears, harmonic drives have numerous advantages, but there are some disadvantages as well. Their main advantages include: high torque capacity, excellent positioning accuracy and repeatability, compact design, zero backlash, high single-stage reduction ratios and high torsion stiffness.
What is harmonic drive in robotics?
Harmonic Drive® rotary actuators are the easiest solution for your high precision motion control applications. Performance matched precision gearing, motors, and encoders are designed to provide a power dense, cost effective solution.
Is Harmonic Drive back drivable?
Backdrivability of a harmonic drive, when used as torque increaser, means that the output shaft can be rotated via finite amount of torque. A high ratio harmonic drive is non-backdrivable because its output shaft cannot be turned by applying a torque on it.
How are gears used in robotics?
In Robotics Gears are used to transfer rotational forces between axles. They can change speed and direction. The axles can stand in any orientation, however not all orientation can be done with 2 gears. Commonly gears are used to reduce the speed of a motor.
How is strain wave gearing used in robotics?
Strain wave gearing is commonly used in robotics and aerospace. It can provide gear reduction but may also be used to increase rotational speed, or for differential gearing . The basic concept of strain wave gearing (SWG) was introduced by C.W. Musser in a 1957 patent while he was an advisor at United Shoe Machinery Corp (USM).
What is the gear set for Harmonic Drive SE?
Harmonic Drive SE strain wave gear set consisting of wave generator bearing (top left), flexspline cup (top right) and circular spline ring (bottom).
How is the gearing reduction ratio of a strain wave calculated?
For a strain wave gearing mechanism, the gearing reduction ratio can be calculated from the number of teeth on each gear, in a similar manner to a cycloidal drive : For example, if there are 202 teeth on the circular spline and 200 on the flex spline, the reduction ratio is (200 − 202)/200 = −0.01
Who is the inventor of the harmonic gearbox?
Our RDrive servos use harmonic gearboxes that are based on strain-wave gearing that was invented in 1957 by C.W. Musser. Since then, the technology has evolved to provide the following benefits: Almost-zero backlash | Enhanced performance, improved positioning accuracy, and a long and maintenance-free service life of servo motors.