BALL BEARING UNIT WITH AN IMPROVED BALL RETAINING CAGE

摘要

A ball bearing unit comprises an outer race (30), one or two inner races (31, 32), one or two series of balls (14) arranged between the inner race and the outer race. The balls have a diameter (D14) and centres (C14) arranged along a pitch line (P14) having a diameter (d14). The bearing unit comprises at least one cage (10) for keeping the balls (14) equally spaced along said pitch line. The cage forms a plurality of sockets (13) for receiving the balls (14). Each socket (13) forms a part of a hollow spherical surface (S) having a centre (C13) and a diameter (D13) slightly greater than the diameter (D14) of the balls (14). The centres (C13) of the spherical surfaces (S) are arranged along a circumference (P13) having a diameter (d13). The diameter (d13) of the circumference (P13) passing through the centres of the spherical surfaces (S) is smaller than the diameter (d14) of the pitch line (P14) passing through the centres (C14) of the balls (14).