Patent ID: 7216723

Claim:
A pulse torque generator comprising: an input shaft having an axis and an inner peripheral surface, the input shaft being connected to a drive source and rotatable about the axis, the input shaft being provided with a hollow section extending in an axial direction of the input shaft and including at least one magnetic section and at least one non magnetic section, the hollow section providing a hollow space; an output shaft rotatably extending through the hollow space and having an outer peripheral surface, an annular gap being defined between the inner peripheral surface and the outer peripheral surface; a magnetic fluid encapsulated in the annular gap; and at least one magnetic field generating unit disposed at a radially outside of the hollow section, the magnetic section and the non-magnetic section being alternately confrontable with the magnetic field generating unit by the rotation of the input shaft, the magnetic fluid providing a magnetic bridge bridging between the input shaft and the output shaft each time the magnetic section is brought into confrontation with the magnetic field generating unit for pulsatingly transmitting rotation of the input shaft to the output shaft through the magnetic fluid bridge.