In the manufacturing process of cross cylindrical roller bearings, the axial clearance of the bearings after assembly sometimes meets the design requirements, while the rotational flexibility is poor or even stuck.Therefore, the reasons affecting the activity of cross roller bearing rotatory recording are analyzed as follows.

I. structure analysis of cross cylindrical roller bearing

The structure of cross cylindrical roller bearing is shown in FIG. 1. Its adjacent rollers are arranged in a 90-degree cross arrangement, and the inner ring or outer ring is divided into upper and lower parts, which is convenient for installing rollers and adjusting axial clearance, and can bear axial, radial load and overturning torque.

II. Reasons affecting the rotational flexibility of cross cylindrical roller bearing

The reasons that influence the rotational flexibility of cross-cylindrical roller bearing are mainly from the two aspects of design and machining, which are embodied in the following aspects:

1. The length and size of cylindrical roller are not qualified relative to its diameter, causing chord arc interference between the end face of roller and raceway.

2. The raceway roundness value required by the design is inappropriate or the machining value is out of tolerance.

3. The raceway oil groove is processed too shallow or the groove bottom of the raceway oil groove is tangent to the junction of the raceway, and the chamfering Angle of the end face of the cylindrical roller is too small.

4. The diameter surface of ring stop and the coaxial machining of raceway are out of tolerance.

5. Excessive parallelism of fitting surface or end facing raceway.

6. The coaxiality of the upper and lower raceways of the integral ring is out of tolerance.

7. Mix different types of cylindrical rollers with similar sizes for assembly.

cross roller bearing rotation record activity of effective solutions

III .The problem of rotational flexibility must be solved from two aspects: design and machining.

1. Problems needing attention in the design of cross roller bearing

In order to avoid chord – arc interference, the length of roller must be L.And the diameter of the roller d.Satisfy the following relations:

2. Problems needing attention in machining of cross roller bearing

Before machining the diameter surface of the stop steps and raceway, the diameter surface and raceway should be benchmarked to each other, and the machining can be done after alignment, and the processing is best done in a clamping process.

Processing ring width, joint surface and before the race, must make the bedding, after processing, check the difference of parallel `, d control within the bearing axial clearance value.

When grinding raceway, the machining accuracy of the machine tool is required to meet the process requirements. The clamping force of the clamp is along the axial direction of the ring to ensure the roundness and coaxiality of the raceway.The two raceways of the integral ring had better be ground at the same time or completed in a clamping process.

Raceway oil groove had better be changed to figure 2 shape, make h car = h+ train h, train h=/4 X raceway allowance,h shall not be less than 0.7mm, and the chamfering of rollers shall be controlled according to relevant standards.
In a word, we should strengthen the management of production site and technology to avoid problems in product design or processing, so as to ensure product quality.