As one of the key supporting parts of industrial robots, industrial robot bearings mainly include two types of bearings for industrial robots, one is a thin-walled bearing of equal cross-section, and the other is a cross roller bearing. In addition, there are harmonic reducer bearings, linear bearings, joint bearings and so on, but mainly the first two bearings.
The development of modern industrial robots tends to be lighter. For bearings to be installed in a limited space, they must be small and light, that is, lightweight. But at the same time, the high load, high rotation accuracy, high running stability, high positioning speed, high repeated positioning accuracy, long life, and high reliability of the robot require the supporting robot bearings must have high load capacity, high precision, high Stiffness, low friction torque, long life, high reliability performance. Lightweight and high performance are a contradiction.
1. Thin-walled equal-section bearings
Different from ordinary bearings, the cross-section of each series of thin-walled bearings of equal section is mostly square, and the size is designed to be a fixed value: the cross-sectional size in the same series is constant, it does not increase with the increase of the inner diameter size , So it is called a thin-walled bearing of equal section. Equal cross-section thin-walled ball bearings include thin-walled four-point contact ball bearing series, thin-walled angular contact ball bearing series and thin-walled deep groove ball bearing series. They are mostly used in the waist, elbow and wrist of industrial robots. 3. Limited parts. In the case of the same inner diameter size, thin-walled equal-section ball bearings have more steel balls than standard rolling bearings. Therefore, the internal force distribution of the bearing is improved, the elastic deformation at the contact between the steel ball and the channel is reduced, and the bearing Carrying capacity.
2. Thin-wall cross roller bearings
The internal structure of the thin-walled cross-cylinder roller bearing adopts rollers arranged at 90° to cross each other perpendicularly. A single bearing can simultaneously bear the combined action of radial force, bidirectional axial force and overturning moment. There is a spacer between the rollers Or the isolation block can prevent the tilt of the rollers or the mutual grinding between the rollers, which effectively prevents the increase of the friction torque. In addition, the vertical cross arrangement of the rollers can avoid the locking phenomenon of the rollers; at the same time, because the inner and outer rings of the bearing are divided structures, the gap is adjustable, and even if pressure is applied, higher rotation accuracy can be obtained. Crossed roller bearings are widely used in industrial robots for waist rotation, articulated robot shoulders, arms, wrists and other rotating parts due to their light composite structure, high rotation accuracy, good rigidity and stable friction torque.
3.RV reducer bearing
4. Special bearing for harmonic reducer
Harmonic reducer is a kind of controlled elastic deformation of flexible wheel by wave generator, which uses flexible elastic deformation of flexible bearing to transmit motion and power. It is characterized by compact structure, high motion accuracy, large transmission ratio, and multi-purpose. For small and medium torque robot joints.
Harmonic reducer bearings can be divided into two categories: CSF/CSG series harmonic reducer bearings with split outer ring and integral inner ring, and SHF/SHG series harmonic reducer bearings with integral inner and outer ring according to the occasion of use. The rolling elements of the harmonic reducer bearings are cylindrical rollers, which are distributed in V-shaped raceways arranged vertically at 90 degrees to each other. The structural characteristics of the harmonic reducer bearing make a harmonic reducer bearing can withstand axial load, radial load and overturning torque in all directions at the same time, and has high stiffness, rotation accuracy and composite bearing capacity; The robot harmonic reducer bearing also belongs to the cross roller bearing series. The bearing has high precision, flexible operation, small clearance and small error. The compact shape and the bearing have mounting holes for customers to install directly. It is suitable for various types of harmonics. Wave reducer. Such bearings account for approximately 35% of China’s industrial robot bearing market. And it’s growing fast.
Harmonic reducer special cross roller bearings, outer ring and inner ring are also integral structure, but the inner ring and harmonic reducer rigid wheel is an integrated structure, further reducing the thickness and weight of the harmonic reducer, using Special materials and heat treatment process make it have excellent performance, suitable for SHD series harmonic reducer.
It is one of the core components of the harmonic reducer. The elastic deformation of the flexible bearing achieves the requirement of high reduction ratio, and the life of the harmonic reducer depends largely on the life of the flexible bearing. The flexible bearing continuously changes with the elastic deformation of the flexible wheel during the work, and not only bears the cyclic stress load, but also withstands the alternating stress load.