Patent ID: 7144347

Claim:
A differential limiting device for a vehicle comprising: a housing rotatable about a rotational axis; first and second inner shafts arranged in the housing in tandem on the rotational axis and each rotatable relative to the housing; a ring gear provided in the housing to be rotatable bodily with the first inner shaft; a sun gear provided on the second inner shaft in the housing to be rotatable bodily with the second inner shaft; a planetary carrier rotatable bodily with the housing in the housing and provided with a support portion; at least one planetary gear rotatably carried by the support portion of the planetary carrier in meshing engagement with the sun gear and the ring gear; a cam ring provided in tandem with the second inner shaft in axial alignment and rotatable relative to the second inner shaft; a pilot clutch for transmitting drive power between the housing and the cam ring when in friction engagement, to selectively effect relative rotation between the cam ring and the second inner shaft; pilot clutch control means for controlling the friction engagement of the pilot clutch; a cam mechanism including cam grooves formed on mutually facing end surfaces of the cam ring and the second inner shaft and cam followers held in the cam grooves for axially moving the second inner shaft upon relative rotation between the cam ring and the second inner shaft; and a main clutch provided for transmitting drive power between the housing rotatable bodily with the planetary carrier and the first inner shaft rotatable bodily with the ring gear, with outer and inner clutch plates thereof being spline-engaged respectively with the housing and the first inner shaft, whereby the main clutch operates to limit the relative rotation between the planetary carrier and the ring gear when brought into friction engagement by the axial movement of the second inner shaft.