Crossed cylindrical roller slewing bearing is a type of crossed roller bearing. It is mainly composed of two races, a single row of crossed cylindrical rollers, a cage (spacer block), a sealing device and other parts. It is widely used in the waist rotation of robots such as handling and palletizing, rotary disks with high precision and rigidity on automation lines, welding station turntables, large-diameter rotary disks, tower cranes with medium and larger diameters, and truck cranes. Below, we will introduce you to the features of crossed cylindrical roller slewing ring.
1. Cross cylindrical turntable bearing can carry loads in all directions
The crossed cylindrical turntable bearing has only one row of rolling elements, but the rolling elements are short cylindrical rollers. The axes of adjacent rollers are arranged in a 90° cross arrangement, and the inner and outer rings each have two raceways. Half of the rollers bear downward axial force, and half bear upward axial force. This bearing can withstand radial forces, axial forces and overturning moments. Usually the length of the cylindrical roller should be 0.5~1mm shorter than its diameter, the integral structure is simple and the rigidity is good.
2. Isolation block of crossed cylindrical turntable bearing
Crossed Cylindrical Roller Slewing Bearings are available with or without spacers. Most slewing bearings used in construction machinery do not have spacers.
3. The clearance of the crossed cylindrical turntable bearing can adjust
Cylindrical cross-roller slewing bearings are mostly made into separate types to facilitate installation of rolling elements and adjustment of clearance. But there are also integral ones, like four-point contact balls, which use filling holes to fill the rollers, and use options to adjust the axial clearance. After the rollers are full, some clearance is also required, and the total clearance between the rollers is usually about 0.5d in the circumferential direction.
4. Cross cylindrical turntable bearing can effectively prevent the increase of rotational torque
The rollers used in the internal structure of the crossed cylindrical roller slewing bearing are arranged at 90° perpendicular to each other. Spacers or spacers are installed between the rollers, which can prevent the inclination of the rollers or the mutual friction between the rollers, and effectively prevent the increase of the rotational torque. In addition, there is no contact or locking phenomenon of one of the rollers.
5. The crossed cylindrical turntable bearing can rotate with high precision
The clearance of the non-standard cross-roller slewing bearing can be adjusted because its inner and outer rings are divided structures, and high-precision rotary motion can be obtained even if preload is applied.
6. The operation of the crossed cylindrical turntable bearing is easy
The divided inner or outer ring, after the rollers and spacers are installed, are fixed together with the cross-roller slew ring to prevent separation from each other, so the installation of the cross-roller ring is very simple.
7. The crossed cylindrical turntable bearing can prevent the roller from falling sideways
The mutual friction between the rollers is eliminated by the spacer, and the rollers can be prevented from falling sideways, so that a stable rotational torque can be obtained.
8. The cross cylindrical turntable bearing greatly improves the rigidity
Different from the use of double row angular contact ball bearings, since the rollers are arranged vertically and crossed, only one crossed roller collar can bear loads in all directions, and the rigidity is increased by more than 3 to 4 times.
The above is an introduction to the characteristics of the cylindrical cross-roller slewing bearing. In fact, the slew bearing design structure and application of the crossed cylindrical roller slewing bearing is basically the same as that of the four-point contact ball slewing bearing, except that the rolling elements change from steel balls to rollers, and the contact between the rolling elements and the inner and outer rings changes from point contact to line contact.