Resin pulley

Abstract

A pair of annular grooves (19) are formed in the outside-diameter surface of an outer race (11) of a rolling bearing (10) in which a pulley body (30) is molded from a resin, a linear knurl is molded by rolling in the outside-diameter surface of an annular protruding section (20) formed between the pair of annular grooves (19), and groove-shaped recesses (21) and projections (22), both of which reach the pair of annular grooves (19) at both ends, are provided alternately in the circumferential direction. The diameter ([phi]B) of a circle through the groove bottoms of the recesses (21) is greater than the diameter ([phi]A) of a circle through the groove bottom of either annular groove (19) ([phi]B > [phi]A). The pulley body (30) is molded from a resin on the outside-diameter surface of the outer race (11), and protruding parts (36), formed by filling the groove-shaped recesses (21) with a melted resin which is then solidified, are engaged with the projections (22) to prevent creeping.

Description

technical field [0001] The present invention relates to a resin pulley for guiding the movement of a timing belt of an automobile engine and a belt for driving an auxiliary machine. Background technique [0002] Idle pulleys that guide the movement of timing belts and auxiliary drive belts, and tension pulleys used to adjust belt tension are widely used in rolling bearings in terms of weight reduction and cost reduction. A resin pulley with a pulley body made of synthetic resin molded on the outer diameter surface of the outer ring. [0003] In the above-mentioned resin pulley, the material of the outer ring in the rolling bearing and the material of the pulley body have different coefficients of linear expansion, and therefore, the holding force of the outer ring of the pulley body may decrease due to the difference in the amount of thermal expansion due to temperature rise, Thereby, relative sliding (creep) occurs between the outer ring and the pulley main body. [0004]...

AI Technical Summary

Problems solved by technology

[0009] However, in the case of preventing mutual creep between the outer ring and the pulley main body by knurling, if the groove depth of the groove-shaped recesses of the ruled knurling is shallow, it cannot play a large role in preventing creep. effect, so it is necessary to form a relatively deep groove-shaped recess

[0010] At this time, in the resin pulleys described in Patent Documents 1 and 2, locking grooves are formed on the outer diameter surface of the outer ring, and knurling is performed on the bottom surface of the locking grooves to form groove-shaped recesses and protrusions. Knurls are arranged alternately in the circumferential direction. Therefore, if the groove depth of the groove-shaped recesses becomes deeper, the machining load applied to the outer ring will increase and the outer ring will deform.

Due to this deformation, when the rolling bearing rotates, abnormal noise or chattering occurs, thereby reducing the rotation accuracy, resulting in a decrease in the function of the bearing, and there are some cases where a deep groove-shaped recess that is highly effective in preventing creep cannot be formed. bad situation

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