US Patent 7247118 Limited slip differential device

A limited slip differential device has differential gears, a clutch to limit the differential function of the differential gears, and a electromagnetic solenoid including a plunger and a coil. The plunger is set to move forward to engage the clutch by electromagnetic force of the coil in a differential limit state and move backward by a return spring to disengage said clutch in a differential limitless state. The plunger contacts with a contacting member in at least one state of the differential limit state and the differential limitless state, and their contact area is set smaller than a facing area between them in at least the one state.