Toyota Jidosha Kabushiki Kaisha

Keisuke Takimura

Nobuaki Katayama

Kan Sasaki

Takeharu Koide

Fumitomo Tsuchiya

Kinya Yoshii

Hideo Hamano

In a power transfer device for four-wheel drive including a differential arranged to split the driving torque from a power transmission into two torque delivery paths, a first output shaft assembly in drive connection to the differential to transfer the split driving torque to front or rear-wheel drive axles and a second output shaft assembly in drive connection to the differential to transfer the split driving torque to rear or front-wheel drive axles, one of the output shaft assemblies being composed of a pair of split shafts, a shift mechanism includes a clutch sleeve slidably mounted on one of the split shafts for rotation therewith and shiftable between a first position where it is engaged with the other split shaft and a second position where it is disengaged from the other split shaft, a manually operated plug member rotatably coupled within a corresponding bore in the peripheral wall of a housing of the transfer device, and a fastening bolt threaded into the peripheral wall of the housing to fasten the plug member to the housing at a rotated position, the plug member having an inner end portion integrally provided with an eccentric cam pin which is engaged with an annular groove formed on the clutch sleeve.

Power transfer device for four-wheel drive

In combination with a power transmission for an automotive vehicle, a power transfer device includes a transfer casing secured at one side thereof to a casing of the power transmission, a ring gear rotatably mounted within the transfer casing to be applied with driving power from the power transmission through a center differential, and an output shaft assembly mounted within the transfer casing to transmit the driving power from the ring gear to a propeller shaft. The output shaft assembly includes a drive pinion integrally formed with an internally splined hollow shaft portion rotatably mounted within the transfer casing and being in mesh with the ring gear, and an externally splined slide shaft axially slidably coupled within the hollow shaft portion of the drive pinion for rotation therewith and having an output end portion for drive connection to the propeller shaft.

Output shaft assembly in power transfer device

A power transfer device for four-wheel drive includes a center differential of the bevel gear type arranged to split the driving torque from a power transmission into two torque delivery paths respectively for front-wheel drive and rear-wheel drive, a front-drive differential of the bevel gear type arranged coaxially with the center differential at one side thereof to transfer the split driving torque from a side gear of the center differential to front-wheel axles, an output gear for rear-wheel drive arranged coaxially with the center differential at the other side thereof to transfer the split driving torque from another side gear of the center differential to rear-wheel axles, and a limited-slip differential in the form of a viscous coupling assembled with a mounting case for the output gear to effect limited-slip torque proportional to the difference in rotational speed between the side gears. In the transfer device, a clutch mechanism is arranged between the center differential and the mounting case for the output gear to selectively render the limited-slip differential inoperative.

A support structure of a power transfer device arranged in parallel with an internal combustion engine and integrally assembled with a transmission unit secured at one side thereof to a cylinder block of the engine, which includes a first stiffener fastened at one end thereof to an end portion of a casing of the power transfer device and at another end thereof to the cylinder block of the engine, a second stiffener fastened at one end thereof to an intermediate portion of the power transfer casing and at another end thereof to the cylinder block of the engine, and a third stiffener fastened at one end thereof to a casing of the transmission unit and at another end thereof to the cylinder block of the engine, wherein the stiffeners are made of cast iron.

Support structure of power transfer device in combination with

A power transmission for automotive vehicles includes a trans-axle housing formed therein with first, second and third compartments which are in open communication with each other and store therein an amount of lubricating oil, a change-speed gear transmission mounted within the first compartment, a first transfer gear mechanism mounted within the second compartment and in drive connection with the gear transmission, and a second transfer gear mechanism mounted within the third compartment and in drive connection coaxially with the first transfer gear mechanism. For sufficient lubrication of the second transfer gear mechanism, an oil pump is mounted within the first compartment to be driven by the output drive power from the gear transmission and is connected to a communication passage extending to the third compartment through the second compartment to introduce lubricating oil discharged from the oil pump into the third compartment.

Power transmission for automotive vehicle

In combination with a power transmission, a power transfer device comprises a transfer casing detachably secured to a transmission casing, a first differential rotatable within the transmission casing and having a first gear casing driven by an output gear of the transmission, a second differential coaxial with the first differential having a second gear casing integral with an output element of the first differential and rotatable within the first gear casing, a carrier member rotatably mounted within the transfer casing and arranged coaxially with the first and second differentials, a first axle connected with an output element of the second differential and extending outwardly from the transmission casing, a second axle connected with another output element of the second differential and extending outwardly from the transfer casing through the carrier member, a hollow shaft in surrounding relationship with the second axle and connected at its opposite ends with another output element of the first differential and the carrier member, and a clutch sleeve slidably mounted on the hollow shaft to be engaged with the first gear casing. The clutch sleeve is arranged to be axially slidably coupled with the carrier member and to be positioned by engagement with the carrier member.

The present invention relates to a transaxle mechanism for use in a four-wheel drive system of an automotive vehicle. The four-wheel vehicle drive system includes a central differential gear assembly, a front-wheel differential gear assembly, a ring gear and a bevel gear. The central differential gear assembly includes: a toothed wheel which engages with a transmission output gear of a power transmission gear unit; a central differential case fixed to the toothed wheel; a central pinion cross shaft fixed to the central differential case; central differential bevel pinions mounted rotatably on the central pinion cross shaft and central side bevel gears engaging with the central differential bevel pinion. The front-wheel differential gear assembly include; a front-wheel differential case fixed to one of the central side bevel gears; a front-wheel pinion cross shaft fixed to the front-wheel differential case; front-wheel differential bevel pinions mounted rotatably on the front wheel pinion cross shaft; front-wheel side bevel gears engaging with the front wheel differential bevel pinions and being secured to front wheel shafts. A second of the central side bevel gear has a hollow shaft portion within which one of the front shafts is inserted and a hub case is fixed to the hollow shaft portion of the second of central side bevel gear. The ring gear fixed to the hub case and the ring gear engages with the bevel gear which is connected to a propeller shaft. The ring gear is located apart from the central differential gear assembly and is located adjacent to the central longitudinal line of the vehicle.

Four-wheel vehicle drive system

A differential gear for automotive vehicles comprising a washer interposed between the backs of pinions and the inner surface of a differential casing and fitted to a pinion shaft. The washer has at most a thickness of l tan.alpha. wherein l represents a displacement from an uncompressed condition of a spring washer to a compressed condition thereof exhibiting a predetermined pressure against the side gears. With this arrangement, the pinions may be installed into the differential casing without applying any pressure through the spring washers to the side gears, and after installation of the pinions into the differential casing, pressure between the meshed gear teeth of the side gears and the pinions may be desirably determined.

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Toyota, Japan

Keisuke Takimura