Understand the technical terms in servo planetary reducer

In some technical documents or communication documents of servo planetary reducer, we often see professional terms such as reduction ratio, rated output torque, speed, backlash and so on. For some friends who are not familiar with the reducer, they may be confused. In order to solve the doubts of these friends, the reducer manufacturer-Fu Bao Science and Technology Xiaobian will explain the meaning and function of these technical terms.

1. Deceleration ratio

Deceleration ratio is the ratio of torque to rotational speed between input force and output force of servo planetary reducer, where torque is in direct proportion and rotational speed is in inverse proportion. The reduction ratio burdens the work of reducing the moment of inertia of the mechanism, so that the same motor can drive the mechanism with greater moment of inertia.

2. Backlash

Backlash is also known as backlash and return clearance. Backlash is one of the precision marks of servo planetary reducer, and is generally expressed in angular unit Arc minutes or angular minutes (1 arc minute is equal to one sixtieth of 1 degree). Refers to the angle that the reducer can rotate when the gearbox is fixed at the input end, which is the clearance value between gear sets. If the mechanism itself is light load and has no reverse demand, the backlash can be ignored; Back clearance is very important for accuracy and positioning in precision applications such as robots, automation or CNC, which need to be reversed.

3. Rated output torque

The output torque is an important parameter for selecting the servo planetary reducer. The motor can provide a large output torque after the reduction ratio, but the gear set still has the strength limit. Therefore, when the ratio is too large, the gear of the reducer has doubts about overload. At this time, the products with a larger order must be considered according to the rated output torque.

4. Rotational speed

The output rotational speed of the product is inversely proportional to the gear ratio. After passing through the reduction gear set, the high rotational speed of the motor will be converted into a lower rotational speed, and then output by the output end of the reducer, which is the basic function of the reducer.

5. Axial radial force

The service life of the servo planetary reducer is generally 20,000 hours, and the service life of the product depends on the bearings used. When the bearing speed is high and the stress is large, the service life of the product will be shortened. Based on the output speed of 100rpm, the maximum stress capacity of the bearing life of 20,000 hours is calculated, which is the allowable axial radial force marked by the reducer parameters.

6. Torsional rigidity

Although the servo planetary reducer is rigid, it will still be deformed when stressed. Therefore, the reducer manufacturer will provide the torque value required for each deformation of 1 arc minute (1/60th degree) for users' reference.

7. Moment of inertia

Although the servo planetary reducer can reduce the moment of inertia of the mechanical end and the load of the motor end, it still has its own moment of inertia. In addition, when the product has poor concentricity and the gear set interferes, it will produce redundant moment of inertia. Therefore, the reducer manufacturer will generally provide the maximum moment of inertia of the product for the user's reference.