What are the categories of industrial robot bearings?

As one of the key components of industrial robots, industrial robot bearings are most suitable for the joints or rotating parts of industrial robots, the rotating table of machining centers, the rotating part of manipulators, precision rotating tables, medical instruments, measuring instruments, and IC manufacturing. devices and so on. The industrial robot bearings mainly include two categories, one is equal-section thin-walled bearings, and the other is cross-cylindrical roller bearings. In addition, there are harmonic reducer bearings, linear bearings, joint bearings, etc., but mainly the first two bearings.

Features of industrial robot bearings:

1. It can withstand comprehensive loads in axial, radial and overturning directions;

2. Thin-walled bearings;

3. High rotary positioning accuracy. Any bearing that meets this design requirement can be used in industrial robot arms, rotary joints, chassis, etc.

Types of Industrial Robot Bearings

1. Cross roller bearing

Crossed roller bearings are cylindrical rollers or tapered rollers arranged vertically on the 90-degree V-shaped groove rolling surface through spacers, so crossed roller bearings can bear radial loads, axial loads and moment loads and other multi-directional loads. The size of the inner and outer rings is miniaturized, and the extremely thin form is even closer to the limit of small size, and has high rigidity, and the precision can reach P5, P4, and P2 levels. Therefore, it is suitable for joints and rotating parts of industrial robots, rotating tables of machining centers, precision rotating tables, medical equipment, calculators, military industry, IC manufacturing equipment and other equipment.

(1) Excellent rotation accuracy

The internal structure of the crossed roller bearing adopts rollers arranged vertically and crosswise at 90°, and spacers or spacers are installed between the rollers, which can prevent the inclination of the rollers and grind each other between the rollers, effectively preventing the rotation torque increase. In addition, there will be no one-sided contact phenomenon or locking of the rollers; at the same time, because the inner and outer rings are divided, the gap can be adjusted, and high-precision rotary motion can be obtained even if preload is applied.

(2) Simplified operation and installation

The outer ring or inner ring divided into two parts is fixed together after the rollers and cages are installed, so the installation operation is very simple.

(3) Withstand large axial and radial loads

Because the rollers are vertically arranged on the 90° V-groove rolling surface through the spacer, this design enables the crossed roller bearing to withstand large radial loads, axial loads and moment loads, etc. direction load.

(4) Significantly save installation space

The size of the inner and outer rings of the crossed roller bearing is minimized, especially the ultra-thin structure is a small size close to the limit, and has high rigidity, so it is most suitable for the joints or rotating parts of industrial robots, and the rotation of machining centers It can be used in a wide range of applications such as worktables, manipulator rotating parts, precision rotary tables, medical instruments, measuring instruments, and IC manufacturing equipment.

Crossed Roller Bearing Type

RB type (outer ring split type, for inner ring rotation)

This series of models is the basic type of crossed cylindrical roller bearings. The size of the inner and outer rings is miniaturized to a minimum. Its structure is that the outer ring is a split type and the inner ring is an integrated design. It is suitable for parts that require high rotation accuracy of the inner ring. 

RE type (inner ring split type, for outer ring rotation)

This series of models is a new type produced by the design concept of RB type, and the main dimensions are the same as RB type. Its structure is that the inner ring is a split type, and the outer ring is an integrated design, which is suitable for parts that require high rotation accuracy of the outer ring.

RU type (integrated inner and outer rings)

This series of models does not need a fixed flange and a support seat because the mounting holes have been processed. In addition, due to the integrated inner and outer ring structure with seats, installation has little effect on performance, so stable rotation accuracy and torque can be obtained.can be used for outer ring and inner ring rotation.

CRB type (outer ring split type, for inner ring rotation)

Its structure is that the outer ring is a split type, the inner ring is an integrated design, and it is a full complement roller bearing without a cage. It is suitable for parts requiring high rotation precision of the inner ring.

CRBC type (outer ring split type, for inner ring rotation)

Its structure is that the outer ring is a split type, the inner ring is an integrated design, and it is a full complement roller bearing with a cage. It is suitable for parts requiring high rotation precision of the inner ring.

CRBH type (inner and outer ring integrated type)

The inner and outer rings of this series of models are of integral structure, which is used for the rotation of the outer ring and the inner ring.

RA type (outer ring split type, for inner ring rotation)

This series of models is a compact type that reduces the thickness of the inner and outer rings of the RB type to the limit. Suitable for parts requiring light weight and compact design, such as industrial robots and manipulator rotating parts.

RA-C type (single crack type)

The main dimensions are the same as Type RA. Since this model has a notched outer ring structure, the outer ring also has high rigidity, so it can also be used for outer ring rotation.

XR/JXR Type (Cross Tapered Roller Bearing)

This type of bearing has two sets of raceways and rollers, which are combined at right angles to each other, and the rollers are staggered. The cross-sectional height of the bearing is similar to that of a single row bearing, thus saving space and housing material. The large taper angle and taper geometry design make the overall effective span of the bearing several times the width of the bearing itself. Crossed tapered rollers can withstand high overturning moments and are suitable for machine tools, including vertical boring and grinding machine tables, machine tool precision circular indexing tables, large hobbing machines, turrets, industrial robots, etc.

2. Equal cross-section thin-walled bearings

Equal cross-section thin-walled bearings are composed of seven open series and five sealed series. There are three types of open series: radial contact type C, angular contact type A and four-point contact type X. Advantages of thin-walled equal-section bearings: thin-walled bearings realize extremely thin bearing sections, and also realize miniaturization and light weight of products. The variety of products expands its range of uses.

Product features of thin-walled equal-section bearings: In order to obtain low friction torque, high rigidity, and good rotation accuracy of the bearing, steel balls with small outer diameters are used. The use of the hollow shaft ensures light weight and space for wiring. The thin-walled 6700 and 6800 series have various forms of dust cover, flanged form, stainless steel form, wide form, etc., with a complete range.

The main applications of thin-walled and equal-section bearings are: stepping motors, medical equipment, office equipment, testing instruments, deceleration and transmission devices, robots, optical imaging equipment, and rotary encoders.

Thin-walled equal-section bearings are also called thin-walled ring bearings. They have high precision, are very quiet and have a strong load-carrying capacity. Thin-wall ring bearings can be deep groove ball bearings, four-point contact bearings, angular contact ball bearings, and the cross-section of thin-wall equal-section bearings is mostly square. In these series, the cross-section remains the same even with larger shaft diameters and bearing bores. These bearings are therefore called constant section. It is this characteristic that distinguishes thin-walled ring bearings in the standard ISO series from conventional bearings.

Therefore, larger cross-sections can be selected and bearings with higher load carrying capacity can be used without having to change the shaft diameter. Thin-walled ring bearings can be designed as extremely lightweight bearings that require little space.

The above is the relevant introduction about the bearing categories of industrial robots. In the actual use process, it can be selected according to the needs, so that the use efficiency of industrial robots can be improved to a certain extent.