Industrial robot bearings are mainly equal-section thin-walled bearings and crossed cylindrical roller bearings, in addition to these there are also harmonic reducer bearings, linear bearings, joint bearings, etc. Industrial robot bearings are mainly used in the joint parts or rotating parts of industrial robots, rotary tables of machining centres, rotating parts of robots, precision rotary tables, medical instruments, measuring instruments, IC manufacturing devices and other applications.
The development of modern industrial robots tends to be lightweight. Bearings have to be mounted in a limited space and must be small and light in weight, i.e. lightweight. However, at the same time, the high load, high rotary accuracy, high running smoothness, high positioning speed, high repeat positioning accuracy, long life and high reliability of the robot require that the supporting robot bearings must have high bearing capacity, high accuracy, high rigidity, low friction torque, long life and high reliability.
Industrial robot bearing selection method
1.Model selection
①Thin-walled bearings with equal cross-section
Mainly including thin-walled four-point contact ball bearings, thin-walled angular contact ball bearings, thin-walled deep groove ball bearings, suitable for industrial robots abdomen, elbow, wrist, require precision to P5 level, life of 6000 hours or more.
②Thin-walled crossed cylindrical roller bearings
Crossed roller bearings with its light composite structure, high rotary accuracy, good rigidity, stable friction torque and other good performance is widely used in industrial robots waist rotary, articulated robot shoulder, arm, wrist and other rotary parts. The requirement is that the precision should reach P4 level and the life time should be more than 6000 hours.
③RV reducer bearings
A variety of thin-walled bearings, cylindrical roller cage assemblies, etc. are widely used in industrial robots, requiring precision up to P4 level, temperature rise not more than 30°C and a life of more than 6,000 hours.
④Harmonic Reducer Bearings
Harmonic reducer is a kind of relying on the wave generator to make the flexible wheel produce controlled elastic deformation, using the flexible bearing controlled elastic deformation to transmit motion and power, its characteristics are compact structure, high accuracy of motion, large transmission ratio, mostly used in small and medium torque robot joints. They require an accuracy of P5 (partly P4) and a life of 6,000 hours or more.
Robot harmonic reducer bearings are also part of the crossed roller bearing series, with high precision, flexible running, small clearance and small errors; compact in shape, the bearings come with mounting holes for direct installation by customers and are suitable for various types of harmonic reducers. This type of bearing accounts for about 35% of the industrial robot bearing market and is growing rapidly.
The bearing type is generally selected by the user's technical personnel according to the supporting product's use conditions and bearing load on the bearing.
2. Selection of bearing clearance
Users in the purchase of bearings will generally only inform in what model, grade, rarely will the bearing clearance requirements, need to understand clearly the bearing conditions of use, which bearing speed, temperature, with tolerance are directly related to the choice of bearing clearance.
3.grease selection
The choice of grease is generally based on the bearing speed, temperature resistance, noise requirements and starting torque and other aspects of the choice.
4.The choice of bearing seal type
Seals are divided into contact sealing and non-contact sealing, contact sealing dustproof performance is good but the starting torque is large, non-contact sealing starting torque is small, but the sealing performance is not contact good.