Yutaka Giken Co., Ltd.

Other

Kabushiki Kaisha Yutaka Giken

Koji Inoue

Tokuji Yoshimoto

Yasushi Yamamoto

Nobuyuki Iwao

Hidetaka Koga

Yoshihisa Sugimura

Kousaku Suzuki

Takashi Ogai

A lockup clutch for a torque converter includes a pump extension, a receiving plate connected to the pump extension defining a hydraulic pressure chamber communicating with a portion between a pump impeller and a turbine impeller, a pressing plate opposed to the receiving plate for movement toward and away from the receiving plate, an annular friction clutch plate interposed between the receiving plate and the pressing plate and connected to the turbine impeller, a return spring for biasing the pressing plate in a retracting direction, and an escape bore permitting the inside and outside of the receiving plate to communicate with each other on the side of an inner periphery of the friction clutch plate. When the rotational speed of the pump impeller is increased to a value equal to or higher than a predetermined value, the pressing plate clamps the friction clutch plate in cooperation with the receiving plate under the action of a centrifugal hydraulic pressure within the hydraulic pressure chamber. Thus, the lockup clutch needs no special control but has a simple structure.

Lockup clutch for torque converter

In a fluid coupling with a baffle plate protruding on the side of an inner peripheral surface of a circulating circuit, a clutch chamber is defined between a back of a turbine impeller and a side cover covering the back of the impeller, to communicate with an outer periphery of the circulating circuit. The clutch chamber is divided by a clutch piston into an inner chamber portion on the side of the turbine impeller and an outer chamber portion on the side of the side cover. The clutch piston is axially movably connected to the turbine impeller, thereby constituting a lock-up clutch, so that a first oil passage leading to the outer chamber portion and a second oil passage leading to an inner periphery of the circulating circuit are put into alternate communication with a discharge portion of an oil pump and with an oil reservoir in a switched manner.

Fluid coupling with baffle plate

A torque converter includes a turbine impeller integrally connected to a pump impeller, a side-cover having a boss and covering the turbine impeller, and a turbine shaft extending through the boss and connected to the turbine impeller. A radial bearing and a one-way clutch are disposed axially adjacent to each other between the boss of the side-cover and the turbine shaft. The radial bearing serves to retain the boss and the turbine shaft concentrically, and the one-way clutch connects the turbine shaft and the side-cover to each other, when a back load is applied to the turbine shaft. Therefore, a load received by a clutch element of the one-way clutch such as a sprag between the turbine shaft and the side-cover is equalized. Thus, when a back load is applied to the turbine shaft, a slipping between the turbine impeller and the pump impeller is prevented, thereby providing a good engine brake effect.

Torque converter

In a transmitting system for a small-sized vehicle in which a crankshaft and an input shaft of a transmission are connected to each other through a fluid transmitting device such as a torque converter. A primary reducing device, the fluid transmitting device and a shifting clutch are disposed on the crankshaft sequentially from one side of a crankcase supporting the crankshaft with a bearing interposed therebetween toward the outside, and the axial movements of the input member, the pump impeller and the turbine impeller on the crankshaft are restrained by the bearing and a nut threadedly fitted at a tip end of the crankshaft. Thus, a creep phenomenon of the fluid transmitting device can be eliminated by controlling the shifting clutch, and the shifting operation of the transmission can be conducted lightly. Moreover, the transmitting system is of a simple construction and improved in assemblability.

Transmitting system for small-sized vehicle

In a weld-coupling portion 3 which is formed by fitting an inner peripheral surface 2b of an end portion of a pump shell 2 to a lower-step surface 4a of a stepped portion 4 formed on an outer peripheral surface of an end portion of a front cover 1 of a torque converter and then welding them together while abutting an end surface 2a of the end portion of the pump shell 2 with a stepped surface 4a of the stepped portion 4 of the front cover 1, the weld-coupling portion 3 is cut down to a level of the lower-step surface 4a of the front cover 1 in such a predetermined cutting width as to evenly cut a front cover side and a pump shell side of the weld-coupling portion 3 in order to separate the front cover 1 and the pump shell 2 apart. A new replacement of the pump shell 2N which has an end portion whose length is larger than that of the end portion of a cut pump shell 2C (not illustrated) by the cutting width W is fit to the lower-step surface 4a of the stepped portion of the end portion of the cut front cover 1C. The end surface 2a of the end portion is abutted with the stepped surface 4b of the end portion of the cut front cover 1C to thereby weld-recouple the cut front cover 1C and the new pump shell 2N.

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Hamamatsu, Japan

Koji Inoue