Power transfer device for four wheel drive

Claim 2

A power transfer device for four-wheel drive in combination with a power transmission having a transmission casing secured at one side thereof to a cylinder block of an internal combustion engine, an input shaft rotatably mounted within said transmission casing and arranged coaxially with a crankshaft of said engine, an output shaft rotatably mounted within said transmission casing in parallel with said input shaft, a change-speed gearing mounted on said input and oitput shafts, and an output gear integral with said output saaft, the power transfer device being characterized by: a transfer casing detachably secured at one side thereof to said transmissioi casing; a first inner casing rotatably mounted within said transmission casing; a second inner casing rotatably mounted within said transfer casing and arranged coaxially with said first inner casing; an output gearing assembled within said transfer casing; a first ring gear integral with said first inner casing and in mesh with said output gear on said output shaft; a second ring gear integral with said second inner casing and drivingly connected to said output gearing; a first differential gear unit rotatably assembled within said first inner casing; a first wheel axle drivingly connected at its inner end with said first differential gear unit and extending outwardly through said first inner casing; a second wheel axle drivingly connected at its inner end with said first differential gear unit and extending outwardly through said second inner casing; a second differential gear unit rotatably assembled within said second inner casing in surrounding relationship with said seccnd wheel axle and drivingly connected to said first inner casing and to said first differential gear unit; and means for locking said second differential gear unit.

Claim 3

A power transfer device as claimed in Claim 1, characterized in that said transfer casing is located at the rear of said engine in such a manner that said first and second wheel axles are arranged in parallel with said input and output shafts.

Claim 4

A power transfer device as claimed in Claim 1, characterized in that said first inner casing is rotatably supported by a pair of axially spaced bearings carried on said transmission casing, and said second inner casing is rotatably supported by a pair of axially spaced bearings carried on said transfer casing.

Claim 5

A power transfer device as claimed in Claim 1, characterized in that said first differential gear unit is arranged to provide a front-wheel drive, and said output gearing is arranged to provide a rear-wheel drive.

Claim 6

A power transfer device as claimed in Claim 1, characterized in that a first hollow shaft is arranged in surrounding relationship with said second wheel axle to drivingly connect said first differential gear unit to said second differential gear unit, and a second hollow shaft is arranged in surrounding relationship with said first hollow shaft to drivingly connect said first inner casing to said second differential gear unit.

Claim 7

A power transfer device as claimed in Claim 1, characterized in that the component parts of said first differential gear unit are substantially common to those of an original differential gear unit for front-wheel drive assembled within said transmission casing.

Claim 8

A power transfer device for four-wheel drive in combination with a power transmission having a transmission casing secured to one side thereof to a cylinder block of an internal combustion engine, an input shaft rotatably mounted within said transmission casing and arranged coaxially with a crankshaft of said engine, an output shaft rotatably mounted within said transmission casing in parallel with said input shaft, a change-speed gearing mounted on said input and cutput shafts, and an output gear integral with said output shaft, the power transfer device being characterized by: a transfer casing detachably secured to one side thereof to said transmission casing; a first inner casing rotatably mounted within said transmission casing; a second inner casing rotatably mounted within said transfer casing and arranged coaxially with said first inner casing; ; a drive pinion integral with a pinion shaft rotatably mounted within said transfer casing for connection to rear-wheel axles; a first ring gear integral with said first inner casing and in mesh with said output gear on said output shaft; a second ring gear integral with said second inner casing and in mesh with said drive pinion; a first differential gear unit for front-wheel drive assembled within said first inner casing and including a first gear case rotatably mounted within said first inner casing, a pinion journalled on said first gear case, and a pair of side gears journalled on said first gear case and in mesh with said pinion; a pair of first and second front-wheel axles -espectively connected at tieir inner ends to said side gears, said first front-wheel axle extending outwardly through said first inner caging, and said second front-wheel axle extending outwardly through said second inner casing; a second differential gear unit assembled within said sccona inner casing and including a second gear case rotatably mounted within said second inner casing, a pair of side gears journalled on said second gear case, and a pinion journalled on said second gear case and in mesh with said side gears, one of said side gears being integrally connected to said second inner casing; a first hollow shaft arranged in surrounding relationship with said second front-wheel axle between said first and second inner casings and being integrally connected at one end thereof with said first gear case and at the other end thereof with the other side gear of said second differential gear unit; a second hollow shaft arranged in surrounding relationship with said firs: hollow shaft between said first and second inner casings and being integrally connected at one end thereof with said first inner casing and at the other end thereof with said second gear case of said second differential gear unit; and means for locking relative rotation of said side gears in said second differential gear unit.

Claim 9

A power transfer device for four-wheel drive in combination with a power transmission having a transmission casing secured to one side thereof to a cylinder block of an internal combustion engine, an input shaft rotatably mounted within said transmission casing and arranged coaxially with a crankshaft of said engine, an output shaft rotatably mounted within said transmission casing in parallel with said input shaft, a change-speed gearing mounted on said input and cutput shafts, and an output gear integral with said output shaft, the power transfer device being characterized by: a transfer casing detachably secured to one side thereof to said transmission casing; a first inner casing rotatably mounted within said transmission casing; a second inner casing rotatably mounted within said transfer casing and arranged coaxially with said first inner casing; ; a drive pinion integral with a pinion shaft rotatably mounted within said transfer casing for connection to rear-wheel axles; a first ring gear integral with said first inner casing and in mesh with said output gear on said output shaft; a second ring gear integral with said second inner casing and in mesh with said drive pinion; a first differential gear unit for front-wheel drive assembled within said first inner casing and including a first gear case rotatably mounted within said first inner casing, a pinion journalled on said first gear case, and a pair of side gears journalled on said first gear case and in mesh with said pinion; a pair of first and second front-wheel axles -espectively connected at tieir inner ends to said side gears, said first front-wheel axle extending outwardly through said first inner caging, and said second front-wheel axle extending outwardly through said second inner casing; a second differential gear unit assembled within said sccona inner casing and including a second gear case rotatably mounted within said second inner casing, a pair of side gears journalled on said second gear case, and a pinion journalled on said second gear case and in mesh with said side gears, one of said side gears being integrally connected to said second inner casing; a first hollow shaft arranged in surrounding relationship with said second front-wheel axle between said first and second inner casings and being integrally connected at one end thereof with said first gear case and at the other end thereof with the other side gear of said second differential gear unit; a second hollow shaft arranged in surrounding relationship with said firs: hollow shaft between said first and second inner casings and being integrally connected at one end thereof with said first inner casing and at the other end thereof with said second gear case of said second differential gear unit; and means for locking relative rotation of said side gears in said second differential gear unit.

Claim 10

A power transfer device as claimed in Claim 7, characterized in that said second inner casing is rotatably supported by a pair of axially spaced bearings carried on said transfer casing.

Claim 11

A power transfer device as claimed in Claim 7, characterized in that said transfer casing is located at the rear of said engine in such a manner that said front-wheel axles are arranced in parallel with said input and output shafts, and characterized in that said pinion shaft is arranged in a fore-and-aft direction of the vehicle.

Claim 12

1C. A power transfer device as claimed in Claim 7, characterized in that said means for locking said side gears in said second differential gear unit is a user actuable sleeve member axially slidably mounted on said second front-wheel axle to be moved to a first position in which the one of said side gears is disengaged from said second gear case and moved to a second position in which the one of said side gears is in engagement with said second gear case.