Patent ID: 9245454
Filing Date: 2016-01-26
CPC Classification: A63B,A63F,F16D,G09B

Claim Text:
1. A rotary actuator comprising: a solenoid which generates a magnetic field, thereby forming flux lines, in response to a current being applied thereto; a cylindrical rotor which surrounds inner, outer and top surfaces of the solenoid, the rotor having a rotary shaft disposed in an opened central portion of the solenoid, and being freely rotatable about the rotary shaft; a cylindrical housing which surrounds inner, outer and bottom surfaces of the solenoid, the housing being configured such that the housing engages with the rotor; and a magnetorheological fluid which is injected into the housing and disposed inside gaps among the solenoid, the rotor and the housing, the magnetorheological fluid generating magnetic chains along the flux lines in response to the magnetic field being generated, wherein a cross-section of the rotor is configured such that a thickness of walls of the rotor which surround the inner and outer surfaces of the solenoid decreases in a top-to-bottom direction, and a space having a predetermined width is defined around the rotary shaft, whereby the rotor engages with the housing which has a corresponding configuration.