Ntn Corporation

Kenichiro Itoh

Makoto Yasui

Isao Hori

Shiro Goto

Kenro Adachi

Takayuki Norimatsu

Ken Yamamoto

Koji Akiyoshi

Katsuhisa Suzuki

Hiromi Nojiri

Shiro Gotoh

Kohji Akiyoshi

A two-way clutch is provided which comprises an inner member formed with a plurality of pockets opening toward its outer peripheral surface, an outer member mounted on the inner member and formed with a plurality of pockets opening toward its inner peripheral surface, a cam ring formed with a cam surface on its inner peripheral surface, a plurality of block members received in the pockets of the inner member so as to protrude in a diametric direction, a plurality of resilient members received in the pockets of the inner member for biasing the block members radially outwardly, and a switch spring mounted to the inner member for maintaining a predetermined phase of the cam ring relative to the inner ring. With this construction, the inner and outer members can be engaged through the block members to transmit power by aligning the pockets of the inner and outer members with each other and by controlling the phase of the cam ring. Also, a rotation transmission device is provided which includes a first rotary member, a second rotary member, the above-described two-way clutch, and an electromagnetic clutch.

Two-way clutch and rotation transmission device

A rotation transmission device is mounted in a drive train of a four-wheel drive vehicle to selectively distribute driving force to selected vehicle wheels according to the travel condition of the vehicle. This device includes an outer ring and an input shaft. A cylindrical face is formed on one of the opposed surfaces of the outer ring and the input shaft, while cam faces are formed on the other opposed surface to define a wedge-shaped space between the cylindrical face and each cam face. Rollers are mounted in pockets formed in a retainer mounted between the input shaft and the outer ring. An electromagnetic clutch is coupled to the retainer. A switch spring is mounted between the retainer and the input shaft. A two-way clutch is provided between the outer ring and the input shaft. A control unit controls the two-way clutch by adjusting the amount of current fed through a coil of the electromagnetic clutch according to the travel condition of the vehicle, thus selectively distributing driving force to selected vehicle wheels. A method of controlling the rotation transmission device is also proposed. Also, another transmission device is proposed which is mounted in the transfer of a vehicle.

Rotation transmission device

A hub clutch assembly is designed so that fluid pressure is used only while the driving mode is being changed over between a four-wheel drive position and a two-wheel drive position, while eliminating the necessity of holding a coupling member in position once the driving mode has been changed over. A driven member and a driving member are coupled together and uncoupled from each other by a slider which is moved under a negative or positive air pressure. A spring is used to maintain the slider in the two-wheel drive position, while a magnet is used to maintain the slider in the four-wheel drive position.

Hub clutch assembly

A rotation transmission device mounted on a 4WD car can stop the front drive train during 2WD mode, and also permits smooth changeover from 2WD to 4WD even while the vehicle is moving. The rotation transmission device is mounted in a transfer which transmits the output of the engine transmission to the rear propeller shaft through an input shaft and to the front propeller shaft through a silent chain. The rotation transmission device includes a two-way clutch through which the rotation of the input shaft is selectively transmitted to a chain sprocket, an electromagnetic clutch for selectively locking and unlocking the two-way clutch, and a multiple disk clutch provided between the two-way clutch and the electromagnetic clutch to function as a synchronizer that permits smooth mode change from 2WD to 4WD even while the vehicle is moving.

A hub clutch assembly is designed so that fluid pressure is used only while the driving mode is being changed over between a four-wheel position and a two-wheel drive positions, while eliminating the necessity of holding a coupling member in position once the driving mode has been changed over. A driven member and a driving member are coupled together and uncoupled from each other by a slider which is moved under a negative or positive air pressure. A spring is used to maintain the slider in the drive position, while a magnet is used to maintain the slider in the four-wheel drive position.

A rotation transmission device has a driving member and a driven member rotatably mounted one inside the other. A plurality of engaging elements are mounted between the driving member and the driven member so as to engage with the driving member and the driven member when the driving member and the driven member rotate relative to each other in either direction. A cage is mounted between the driving member and the driven member for keeping the engaging elements apart from one another by a predetermined distance. A turning force imparting mechanism is coupled to the cage for moving the engaging elements to an engageable position by turning the cage in one direction relative to the driving member, and a locking mechanism is provided between the cage and the driven member for detachably coupling the cage to the driven member and remote-controlled through a cable connected to the locking mechanism and extending out of the rotation transmission device.

Rotation transmission device for connecting and disconnecting the

An automotive power transmission device which can change over the driving mode between two-wheel drive and four-wheel drive mode. The device when combined with a differential as an integral unit can be assembled easily. This device includes an axle made up of axially separated first and second portions, a differential coupled to one end of the first portion of the axle and having a differential cover, and a clutch device coupled to the other end of the first portion of the axle which is enclosed in the differential cover. The clutch includes an inner ring connected to the differential, an outer ring connected to a vehicle wheel and rotatably mounted around the inner ring, sprags and cages mounted between the inner and outer rings, a biasing member for biasing and rotating the cages relative to the inner ring, and a locking system for detachably coupling the cage and the outer ring together. While the transfer is set in the two-wheel drive mode, the outer ring is allowed to free-run. During the four-wheel drive mode, the rotation of the axle is transmitted to the wheels through the inner ring, sprags and outer ring.

Power transmission device

A rotation transmission device which has a driving member, a driven member, engaging elements mounted between them, and a device for mechanically changing over the transmission and cut-off of turning effort and which restricts the operation of the changeover device as necessary. Between the outer ring as a driven member and the inner member as a driving member, a retainer holding the sprags spaced from one another is mounted. In the inner member are housed a solenoid and a coupling member engaging the outer ring. The solenoid is actuated by contact of a brush against a slip ring, so that the coupling member couples the outer ring with the inner member, thus causing the sprags to be inoperative.

Rotational transmission device

A hub clutch capable of automatically engaging and disengaging the front wheel axle to and from the wheel hubs according to the difference in rotational speeds therebetween. It has an inner ring coupled to the front wheel axle, an outer ring coupled to the wheel hub, a first retainer and a second retainer provided between the inner and outer rings, and sprags held by the first and second retainers. To one end of the first retainer is coupled a switch spring for producing a turning effort. A turning effort imparting device is coupled to its other end through a one-way clutch. While the vehicle is moving forward, the sprags are kept in a forward-travel ready-to-engage position, with the one-way clutch idling. When the vehicle begins to move backward, the one-way clutch locks, so that the sprags are inclined in the opposite direction to assume a backward-travel ready-to-engage position. When the wheel hub begins to rotate faster than the front wheel axle, the outer ring will overrun the sprags, disengaging the front wheels.

Hub clutch device

A device for mechanically changing over the direction of transmission of turning force in which engaging elements are mounted between its driving member and driven member. It prevents the generation of abnormal noise resulting from the repeated engagement and disengagement of engaging elements when turning force is applied from the driven member. Sprags and sprag-supporting retainers are provided between an outer ring as driven member and an inner member as driving member. Also an elastic member is mounted between the outer ring and the inner member. When turning force is transmitted from the outer ring to the inner member, the inner member and one of the retainers begin rotating first, biased by the elastic member. The retainers thus rotate relative to each other, inclining the sprags in the same direction as the inner member to a ready-to-engage position. The sprags are thus prevented from repeatedly engaging and disengaging, so that there will be no abnormal noise.

A mechanical device to be mounted on a four-wheel drive vehicle capable of transmitting driving force to the rear wheels while the vehicle is being accelerated and cutting off the transmission of driving force to the rear wheels while being braked. This device has an inner member to be coupled in series with a differential or a limited slip differential device, and an outer ring. On the opposite surfaces of the inner member and the outer ring are formed a cylindrical surface and a plurality of cam surfaces, between which are defined wedge-shaped spaces. A retainer is provided between the inner member and the outer ring. It is formed with pockets to receive rollers as engaging elements. A turning effort imparting device is coupled to the retainer through a one-way clutch. A torsion coil spring for producing turning effort is mounted between the retainer and the inner member. When the one-way clutch is switched on or off, the direction of turning effort applied to the retainer changes, so that the direction in which the rotation of the retainer delays with respect to the inner member is reversed. The rollers are thus kept in one of the two opposite engageable positions when the inner member is rotating in either direction.

A large-diameter retainer and a small-diameter retainer for retaining sprags are mounted between the inner member as the driving member and the outer ring as the driven member. The large-diameter retainer is coupled with the inner member with a play in the direction of rotation. A switch spring is attached to one end of both of the retainers. To the other end, a turning effort imparting mechanism is coupled through a one-way clutch. The outer ring is coupled with the output shaft with a play in the direction of rotation which is set to be larger than the abovesaid play. When the inner member rotates, the large-diameter retainer will rotate first to tilt the sprags. After the play in the direction of rotation has disappeared, the coupling member between the outer ring and the output shaft will rotate. Thus, the sprags are always brought to correct ready-to-engage positions.

Growing community of inventors

Shizuoka, Japan

Kenichiro Itoh