Method for setting the axial end play of tapered roller bearings

Abstract

A motor support bearing assembly is provided for a live axle used in locomotives. A wheel is press fit on each end of the axle under high pressure, with a gear secured between the wheels adjacent the pinion end of the axle. The motor support bearing assembly is located between the plain end wheel at the commutator end and the axle gear at the other end, and includes a housing, a tapered roller bearing adjacent the plain end wheel, and another tapered roller bearing adjacent the axle gear. In the motor support bearing assembly process, a master spacer made of hardened metal is placed in a selected space in the assembly. The plain end wheel is pressed onto the axle under high pressure. Axial end play in the motor support bearings is set by applying a spike of additional pressure to the plain end wheel, pressing the bearings together tightly and in some cases pre-loading the bearings. The master spacer is then removed and replaced by a slightly smaller shim, which releases pressure on the bearings and creates end play. The shim can be replaced by a still smaller shim if additional end play is desired. In this manner, and play is reduced significantly. In addition, the pressure with which the assembly is made makes a tighter assembly which lasts longer. Both the reduced end play and the tighter assembly improve performance over time.