Rotating Characteristics of the Needle Bearing

Abstract

Skewing of needle rollers and it's influences on rotating characteristics of the needle bearing are investigated theoretically and experimentally, and the results obtained are summarized as follows. (1) There are two states of skew angle θ. For θ<θ₁, rollers can rotate normally, and θ of each roller is not allways constant. When θ exceeds θ₁, θ increases rapidly up to θ₂, and the pressure between rollers and friction moment increases extreamely. As the inner-race contacts nearer the roller-end, θ becomes to this state more easily. (2) Circumferential clearance C.C. and diametrical clearance D.C. have not any direct relations to θ for θ<θ₁. But, to extend operating condition free from extreme temperature rise and failure of the bearing, it is profitable to make C.C. small and θ_D.C.max larger than θ_C.C.max. Where, θ_D.C.max and θ_C.C.max are max. skew angles calculated for D.C. and C.C. respectively. (3) It is presumed that rollers having long effective length and large end diameter are profitable. (4) The thrust force is induced by skewing of rollers and linearly proportional to the bearing load.