Four-point contact ball bearing

Abstract

The present invention provides a four-point contact bearing where heat generation and wear can be constrained by controlling increase in frictional torque in operation under a preload, noise and vibration in high speed rotation are reduced, and bearing life is extended. In a four-point contact bearing (11), d is the diameter of each of balls (17), Dp the pitch circle diameter of the balls (17) arranged between both raceway surfaces (13a, 15a), Ll the distance, on the pitch circle diameter Dp, between adjacent ones of the balls (17), r a curvature radius of grooves as raceway surfaces (13a, 15a) circumscribing the balls (17) on an outer and an inner raceway (13, 15), and alpha a contact angle between each of the raceway surfaces (13a, 15a) and each ball (17). The values of d, Dp, Ll, r, and alpha are defined by predetermined relationships, so that increase in frictional torque is controlled for constrained heat generation and wear even under a preload where an axial clearance (SA) is negative.

Description

technical field [0001] The present invention relates to a four-point contact ball bearing, and more particularly, relates to an improvement of an ultra-thin-wall four-point contact ball bearing, which can suppress the heat generation and wear of the bearing by suppressing the increase of the friction torque during operation under the action of a preload , and in addition to achieving low-noise and low-vibration operation during high-speed rotation, it can also improve bearing life. Background technique [0002] Figure 13 An example of a CT scanner device as a medical instrument is shown. The CT scanner apparatus 1 irradiates X-rays, which are generated by an X-ray tube 2 and whose intensity is limited to a predetermined value by a wedge filter (not shown) and a slit (not shown), onto an object 3 . X-rays transmitted through object 3 are received by detector 5 . A computer (not shown) receiving the output of this detector 5 forms an X-ray transmission image. [0003] A cy...

AI Technical Summary

Problems solved by technology

Therefore, when the bearing rotates at a high speed under the preload, excessive sliding may occur at the point contact portion between the ball and the raceway surface, and this may cause an increase in frictional moment, which can seriously reduce the life of the bearing. heat generation and wear

[0019] Even with the open cage described in patent document 2, this problem cannot be solved

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