Patent ID: 9657790
Date: 2017-05-23
CPC Classifications: A01G,B05B,B60T,F16D

Claim:
1. A rotational speed control device comprising: a housing containing a viscous fluid; a shaft disposed in the housing and rotatable relative to the housing; a hub assembly secured to the shaft for rotation with the shaft; a rotor coupled with the shaft by way of the hub assembly, wherein the rotor rotates with the shaft until a force on the rotor due to an increase in shearing of the viscous fluid exceeds a friction force between the rotor and the hub assembly, resulting in rotation of the shaft and the hub assembly relative to the rotor; and a spring disposed in the housing and acting on the rotor, the spring biasing the rotor axially on the shaft in a low torque direction, wherein a braking torque between the rotor and the housing is varied according to an axial position of the rotor on the shaft, wherein the hub assembly comprises a hub member having hub threads, and wherein the rotor comprises a thread segment frictionally engaging the hub threads.