Rotary pulse generator having preset sensor gap

摘要

A rotary pulse generator is disclosed for attachment to a rotary machine, such as a motor, having a rotary shaft extending therefrom. The generator includes a rotor which is secured to the shaft for rotation therewith. The rotor has a circumferential surface carrying an annular periodic pulse generating pattern, such as a magnetic pattern. A stator housing is secured to the machine. The stator housing carries a stator assembly including a sensor which is spaced radially from the rotor by a sensor gap. The sensor senses the pulse generating pattern and serves to provide pulses or the like having a frequency related to the angular velocity of the rotor. The sensor assembly includes a support block and a sensor support mounted to the support block for movement relative thereto between a retracted position located away from the rotor and a contact position wherein the sensor block contacts the rotor. A first means serves to drive the sensor block from the retracted position until the sensor block engages the rotor in the contact position. A second means drives the sensor block in a second direction away from the contact position toward the retracted position by a predetermined amount that defines the sensor gap.