Nissan Motor Company Limited

Hiroaki Kuramoto

Hiromasa Sakai

Motoharu Nishio

Yasushi Narita

Tatsuya Nagato

Kazuhiro Yamada

Masaki Nakano

Hiroyuki Hirano

Toshikazu Oshidari

Shinichiro Joe

Hirofumi Shimizu

Eio Sagara

Masayoshi Kimura

Manzaburou Abe

A clutch apparatus includes a torque cam mechanism and a clutch actuator for compressing a clutch disc pack for clutch engagement through the torque cam mechanism. The clutch actuator includes a first fluid chamber for pushing the torque cam mechanism from a first position for all-time clutch disengagement, to a second position toward the clutch disc pack, and a second fluid chamber for pushing the torque cam mechanism from the second position to a third position for all-time clutch engagement toward the clutch disc pack. At the second position, the torque cam mechanism functions as a one-way clutch by extending axially in response to relative rotation between both sides in one rotational direction.

Clutch and infinitely variable transmission

In an infinitely variable transmission, a continuously variable transmission ( ) outputs the rotation of an input shaft ( ) at an arbitrary speed ratio, and a fixed speed ratio transmission ( ) outputs the rotation of the input shaft ( ) at a fixed speed ratio. A planetary gear set ( ) varies the rotation direction and speed of the output shaft ( ) according to the difference of the output rotation speed of the fixed speed ratio transmission ( ) and the output rotation speed of the continuously variable transmission ( ). A sensor ( ) which detects the rotation speed of the input shaft ( ) and a sensor ( ) which detects the output rotation speed of the continuously variable transmission ( ) are provided, and a microprocessor ( ) precisely calculates the rotation direction and rotation speed of the output shaft ( ) from these rotation speeds.

Control of infinitely variable transmission

An infinite Speed ratio continuously variable transmission comprises a power recirculation mode clutch ( ) and direct mode clutch ( ). At least one of the power recirculation mode clutch ( ) and direct mode clutch ( ) comprises an electromagnetic two-way clutch. The electromagnetic two-way clutch maintains the engaged state during excitation and can transmit drive force from both the drive side and non-drive side. On the other hand, when there is a change-over from the energized state to the non-energized state, a one-way clutch state is obtained wherein drive force is permitted only in the transmission direction of drive force in the instant of the change-over to non-excitation. When a drive force is input in the reverse direction to the drive force transmitted in the one-way clutch state, the one-way clutch state is disengaged, and the disengaged state of the clutch is maintained until subsequent re-excitation. Therefore, change-over of the clutch at the rotation synchronous point RSP where the power recirculation mode and direct mode are changed over, can be performed rapidly.

Infinite speed ratio continuously variable transmission

In an infinite speed ratio transmission comprising a continuously variable transmission (,), reduction gear unit (,) and planetary gear set (,), the speed ratio of the continuously variable transmission (,) is controlled by a step motor (,). A range selected by a selector lever (,) is detected by a sensor (,). When the selected range has changed from a stationary range to one of a forward motion range and a reverse motion range, a microprocessor (,) first drives the step motor (,) to a predetermined position (S,, S,). Subsequently, by driving the step motor (,) to an operating position corresponding to a geared neutral point at which the output rotation speed of the infinite speed ratio transmission is zero (S,, S,, S,, S,, S,, S,), the undesirable effects of hysteresis occurring in a relation between the operating position of the step motor (,) and the speed ratio of the continuously variable transmission (,) according to a torque shift of the continuously variable transmission (,) are avoided.

Controller for infinite speed ratio transmission

A creep torque is controlled in a non-finite speed ratio transmission device, wherein a planetary gear unit (,) varies a rotation direction of a final output shaft (,) according to a relative rotation of a toroidal continuously variable transmission (,) and fixed speed ratio transmission (,). The controller comprises a hydraulic cylinder (,) which varies the speed ratio of the toroidal continuously variable transmission (,) by driving a trunnion (,), a shift control valve (,) which supplies a hydraulic pressure to the hydraulic cylinder (,) according to a displacement position, a step motor (,) which displaces the shift control valve (,) according to a command signal, and a mechanical feedback member (,) which feeds back the speed ratio of the toroidal continuously variable transmission (,) to the shift control valve (,). The controller further comprises a sensor (,) which detects a running state of a vehicle, a sensor (,) which detects the real speed ratio of the continuously variable transmission (,), and a microprocessor (,) which outputs the command signal. When the vehicle running state corresponds to a predetermined state, the microprocessor (,) outputs a new command signal based on a required creep torque and the real speed ratio of the continuously variable transmission (,) to the step motor (,).

Speed ratio controller and control method of non-finite speed ratio transmission device

When the pressure of a discharge fluid of an electric pump (1) exceeds a predetermined relief pressure, relief valve (6) discharges a part of the fluid to a drain passage (5). A sensor (8, 10, 11) detects a drain flowrate of the drain passage (5), and feedback control of the rotation speed of the electric pump (1) is performed so that the drain flowrate coincides with a predetermined flowrate. Due to this feedback control, the necessary fluid pressure is maintained while suppressing the drain flowrate to the minimum.

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Yokosuka, Japan

Hiroaki Kuramoto