Abstract: Bearing hubs are typically machined in a lathe. Strict tolerances must be observed because, if the bearing fits too tightly in the hub, it may “lock up” and will not turn. An approach to relax the strict tolerances associated with these bearing hubs is to cut threads or parallel grooves (circumferentially) in the surface in contact with the outer race of the bearing. These threads or the high points between the grooves will deform (crush) when the bearing race is pressed in. The strain, then, in the bearing race is lessened due to the plastic strain of the hub, reducing the chance the bearing will lock up.

Abstract: The shaft monitoring device for monitoring the rotation of a shaft about a longitudinal axis is comprised of an encoder, a stationary housing, and a shaft-engaging member rotatably attached to the stationary housing. The encoder has a target and a proximity sensor located within the housing. The housing is mounted to a stationary object such as a block-type bearing supporting one end of the rotating shaft to be monitored. A first end of the shaft-engaging member is placed against the shaft. The first end firmly engages the rotating shaft, thereby allowing the shaft-engaging member to rotate in unison with the rotating shaft. As the shaft rotates, the target attached to a second end of the shaft-engaging member also rotates in unison. As the target passes over the end of the proximity sensor, the sensor reads the presence of the target and closes a switch. Each time the switch is closed, a pulse is generated.