Factors affecting robot performance and service life?

Factors affecting robot performance and service life

In recent years, there has been an increasing demand from all walks of life to incorporate more industrial robots into production lines, from modern automobile manufacturing to 3C (computer, communications and consumer electronics) product manufacturing. Compared with the special automation equipment on the traditional production line, the robot has flexible operation and outstanding ability, so it is especially suitable for multi-variety and small batch production in order to quickly respond to market changes and consumer needs.
An industrial robot is a three-axis or multi-axis multi-purpose robotic arm controlled by an automatic programmable controller.

The purpose of this article is to discuss various factors that affect the service life and performance of industrial robot joints.

Thermal effect

Temperature is the main factor affecting the service life of industrial robots. As an example of mechatronics technology, the robot joint module integrates a large number of components, including frameless motors, servo drives, special reducer systems, brakes, encoders/resolvers, torque sensors, connecting cables, etc., into a single housing. Minimize the occupied space. In normal operation, there are various heat sources in the robot joint shell, such as gear transmission system, motor winding, brake coil (if applicable), and other electrical/electronic components.
Among them, if a harmonic reducer is used, this transmission system is usually the main heat source, and its total power loss is as high as 30%. This is mainly due to gear meshing friction, viscous shear friction in the lubricant, and metal flexspline Repeat the energy of deformation multiple times in each circle. Other major heat sources include motor windings and brake coils.
Failure to effectively dissipate heat will cause the robot to heat up quickly, reducing the performance of various key components.
 Strain wave transmission
The output shaft of the robot joint module usually rotates at a low speed of 10-40 rpm. The motor usually rotates at a high speed (for example, 1000-4000 rpm for a short time during the joint movement of the robot), so a reducer is used in the robot. This type of reducer system is used in robots to reduce the speed and significantly increase the acceleration torque on the output side of the reducer. This type of reducer system achieves extremely high torque density (torque per unit volume) and torque ratio (torque per mass) relative to its compact size.
The unique performance of the strain wave transmission structure makes it widely used in industry, especially in robots. This is due to its single-stage high transmission ratio, almost zero backlash, simple structure, accurate torque transmission, and high positioning Accuracy/repeatability. The strain wave gear is composed of three main components: an elliptical wave generator, a flexible gear, and a rigid tooth
Wheel (Figure 3). Among them, the flexible gear is the most critical component to realize the long service life of the transmission system. During operation, it will be affected by the amount of elastic deformation generated by the constantly changing elliptical wave generator rotation, and it must also rotate with the smallest angle deflection. Therefore, the flexible gear must be flexible in the radial direction but rigid in the tangential direction in order to accurately transmit the rotational movement.

web:/