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Comparison of Performance Characteristics of Crossed Roller Bearings and Crossed Roller Slewing Bearings

2022-05-26

Crossed cylindrical roller bearings and crossed roller slewing bearings (crossed cylindrical roller slewing rings) are very similar in structure and function. Such as high precision, stable torque, long life and so on. On the CNC machine tool turntable and indexing table, on the CNC vertical grinder, machine tool direct drive motor and other mechanical equipment, the shoulder, waist, wrist, elbow, knuckle and other parts of industrial robots are abandoned, as well as in high-precision medical equipment. More and more traditional designs on precision CNC machining equipment such as optical equipment and optical equipment use precision crossed roller bearings with improved performance.

 

Slewing Bearings

 

Cross-roller slewing bearing is commonly known as cross-roller slewing bearing or cross-roller slewing bearing in China. Large and resistant to damage. Cross-roller slewing bearings are often used in large rotating devices such as bucket wheels, overweight transportation machinery, port machinery, mining machinery, park amusement machines, chargers, construction machinery, and missile launch pads, and play a very important role in construction machinery products. . Precision crossed cylindrical roller bearings have the advantages of high rotation accuracy, strong deformation resistance, large load capacity, and flexible structural design. They are widely used in joints and rotating parts of industrial robots, digital rotary tables, precision test turntables, optical telescopes, large radars Antennas and other precision equipment. As a key component of precision rotating equipment, slewing bearing plays a very important role. The main factors affecting the bearing rotation accuracy are bearing manufacturing accuracy and bearing stiffness.

 

The rollers on a crossed roller bearing are usually arranged in a criss-cross arrangement using cylindrical or tapered rollers in a single channel groove. The rollers are spaced by brass retainers or engineering plastic separating blocks. Offers high rotational accuracy, load-carrying capacity, small form factor, high rotational speed and stiffness for a variety of uses. Crossed roller bearings are suitable for industrial robot joints, digital turntables, DD motors, medical equipment, etc.

 

Advantages of Crossed Roller Bearings

 

1. Crossed roller bearings can be easily assembled in all directions of the main shaft, and mass production is carried out through standardization and serialization, and the assembly is relatively convenient.

 

2. Crossed roller bearings can bear both radial and axial loads, so the structure of crossed roller bearings can be much simpler than that of multi-group combined bearings.

 

3. Crossed roller bearings consume less lubricating oil due to high rotational efficiency and low calorific value.

 

4. The radius and axial size of the crossed roller bearing may be limited, so depending on the space, high precision and high rigidity conditions that require less space conditions and dimensions can be used.

 

Crossed roller slewing bearings and crossed roller bearings have advantages that traditional bearings cannot surpass in all aspects. The following are the characteristics of crossed roller slewing bearings. Schematic diagram of the internal structure of the crossed roller slewing bearing

 

It consists of compact structure, light weight, high manufacturing precision, small assembly interval, high installation precision requirements, 1:1 cross roller arrangement, axial force overturning moment and two races that can bear large radial force at the same time. Since the rollers are vertically aligned with each other on the 90 V-groove rolling surfaces through clearance retainers, crossed roller slewing bearings can withstand higher radial, axial and moment loads in all directions.

 

The main characteristics of crossed roller slewing bearing:

 

First, the structural side crossed roller slewing bearing is relatively simple. Considerable axial and radial load forces and overturning moments can be obtained by intersecting rows of cylindrical rolling elements on a single roller. In addition, the crossed roller slewing bearing does not cause contact or locking on one side of the rollers. The inner and outer rings of the standard crossed roller slewing bearing have a split structure, so the spacing can be adjusted, and high-precision rotational motion can be obtained even under preload.

 

Compared with ordinary slewing bearings, the advantages of crossed roller slewing bearings:

 

1. The level of precision that crossed roller slewing bearings can achieve is much higher than that of ordinary slewing bearings. The achievable radial runout and axial runout are much higher than ordinary slewing bearings.

 

2. The rigidity of the crossed roller slewing bearing is much larger than that of the ordinary slewing bearing, and the working noise is smaller than that of the crossed roller bearing. Therefore, it is recommended to choose the crossed roller slewing bearing in a low-noise working environment.

 

3. Structure Side Crossed Roller Slewing Bearing Compared with ordinary slewing bearing, the structure of crossed roller slewing bearing is relatively simple. Considerable bearing orientations, radial load forces and overturning moments can be obtained by intersecting rows of cylindrical rolling elements on a single roller. To achieve the same effect, ordinary slewing bearings must be arranged on three rows of rollers in sequence through three rows of cylindrical rolling elements. In this way, crossed roller slewing bearings are much smaller and lighter than ordinary three-row roller slewing bearings.

 

Slewing Bearings

 

In terms of structure, the structure of crossed roller slewing bearing and crossed roller bearing is much simpler than that of traditional bearings. With multiple rows of cylindrical rolling elements, considerable axial and radial load forces and overturning moments can be obtained. The structure is relatively simple. Existing bearings must be arranged in the order of multiple sets of bearings to achieve the same effect. This provides great convenience for design and assembly. Compared with the traditional bearing, the cross-roller slewing bearing structure and the single-row roller structure of the cross-roller bearing occupy much less equipment space and greatly reduce the difficulty of assembly.