RA7008UUCC0P5 70*86*8mm crossed roller bearing

RA7008UUCC0P5 70*86*8mm crossed roller bearing

Model RA (Separable Outer Ring Type for Inner Ring Rotation)

A compact type similar to model RB with the thinnest possible inner and outer rings. Optimal for locations requiring a light-weight and compact design such as the swivel portions of robots and manipulators.

Structure and Features

       With the Cross-Roller Ring, cylindrical rollers are arranged with each roller perpendicular to the adjacent

roller, in a 90° V groove, separated from each other by a spacer retainer. This design allows

just one bearing to receive loads in all directions including radial, axial and moment loads.

Since the Cross-Roller Ring achieves high rigidity despite the minimum possible dimensions of the

inner and outer rings, it is optimal for applications such as joints and swiveling units of industrial

robots, swiveling tables of machining centers, rotary units of manipulators, precision rotary tables,

medical equipment, measuring instruments and IC manufacturing machines.

High Rotation Accuracy

       The spacer retainer fitting among cross-arrayed rollers prevents rollers from skewing and the rotational

torque from increasing due to friction between rollers. Unlike conventional types using steel sheet retainers, the Cross-Roller Ring does not cause unilateral contact of roller or seize. Thus, even under a preload, the Cross-Roller Ring provides stable rotation.

       Since the inner and outer rings are designed to be separable, the bearing clearance can be adjusted.

In addition, a preload can be applied. These features enable accurate rotation.

Easy Handling

      The inner and outer rings, which are separable, are secured to the Cross-Roller Ring body after being installed with rollers and spacer retainers in order to prevent the rings from separating from each other. Thus, it is easy to handle the rings when installing the Cross-Roller Ring.

Skewing Prevention

       The spacer retainer keeps rollers in their proper position, thereby preventing them from skewing(tilted rollers). This eliminates friction between rollers, and therefore secures a stable rotational torque.

       Increased Rigidity (Three to Four Times Greater than the Conventional Type) Unlike the thin angular ball bearings installed in double rows, the cross array of rollers allows a single Cross-Roller Ring unit to receive loads in all directions, increasing the rigidity to three to four times greater than the conventional type.