Patent ID: 6685594
Filing Date: 2004-02-03
Classification: B60K,F16D,F16H

Abstract:
A differential limiting device of a differential device mounted on a four wheel drive vehicle having an engine for providing driving power to a front drive shaft and to a rear drive shaft, an automatic transmission mechanically and coaxially connected to a crankshaft of said engine for changing a rotational speed of the crankshaft in accordance with driving conditions, and a transmission output shaft included in said automatic transmission and coaxially connected to said crankshaft via a transmission input shaft for transmitting said driving power to both drive shafts, said differential device having a carrier directly and coaxially connected to said transmission output shaft for absorbing a relative rotational difference between said front drive shaft and said rear drive shaft, said differential limiting device coaxially mounted on said rear drive shaft for limiting said relative rotational difference, said differential limiting device comprising:a clutch mechanism coaxially aligned with said rear drive shaft for engaging and for disengaging said rear drive shaft with said carrier; a clutch piston coaxially mounted on said rear drive shaft for being rotatable therewith and for pressing said clutch mechanism by being retractably movable in an axial direction of said rear drive shaft; a protrusion provided to protrude from an end surface of said carrier so as to confront with said clutch piston; and a cam surface formed on an end surface of said clutch piston for engaging with said protrusion by slidably contacting with said cam surface so as to effectively perform a differential function of said differential limiting device by a relatively axial movement of said protrusion; wherein said differential limiting device is a planetary gear differential device including a sun gear provided on said rear drive shaft and a plurality of pinions meshed with said sun gear and supported on pinion shafts in said carrier; and wherein said protrusion is provided to protrude from said end surface of said pinion shaft so as to confront with said clutch piston.