Abstract: An automatic transmission including an input shaft connected to an output shaft of an engine. A first clutch of a first planetary gear unit is positioned between the input and first output shafts while a third clutch of a third planetary gear unit is interposed between the second and third output shafts. Each of the first and third clutches are engaged by the action of flyweights operated by centrifugal force and disengaged by thrust exerted on helical gears of the planetary gear units. A second planetary gear unit includes a second clutch interposed between the first and the second output shafts. Control means control the second clutch so as to engage the first and the second output shaft or disengage the first and the second output shafts from each other and provide smooth shockless upshifting and downshifting of the automatic transmission.

Abstract: A centrifugal friction clutch for an automatic transmission includes axially movable friction elements supported on and rotated with an input member. Axially slidable clutch elements are supported on a clutch cover, wherein centrifugal weights held by spring members are disposed at predetermined positions on the clutch cover. First retaining means on the clutch cover press the friction members and clutch members against each other so that power can be transmitted when the centrifugal weights are displaced. A first spring bearing member contacting one end of each of the spring members urges the centrifugal weights toward their initial positions while a second spring bearing member contacting the other end of each of the spring members is held in place on the clutch cover by second retaining means engaging the clutch cover. The first and second bearing members are axially movable relative to the input member.

Abstract: An automatic transmission for a vehicle comprises: an input shaft (2) connected to the output shaft of an engine; a first planetary gear unit (10) including a helical sun gear (12), helical planet pinions (13) supported for rotation on a planet carrier (14), and a helical ring gear (11); a first clutch (17) interposed between the input shaft (2) and the first output shaft (15) and capable of being engaged by an action of flyweights operated by centrifugal force and of being disengaged by thrust exerted on the helical gears; a second planetary gear unit (20) including a helical sun gear (22), helical planet pinions (23) supported for rotation on a planet carrier (24), and a helical ring gear (21); a second clutch (27) interposed between the first output shaft (15) and the second output shaft (25) and capable of being engaged by the action of flyweights operated by centrifugal force and of being disengaged by thrust exerted on the helical gears; and a two-speed transmission unit (30) including a first high-spee

Abstract: A variable speed gearing system includes two clutch units 30, 50 placed side by side in the axial direction and provides a plurality of transmission gear ratios in response to the state of engagement of clutches 31, 51 of the two clutch units 30, 50. Axially movable members 26a, 48a of the two clutch units 30, 50 are arranged in such a manner as to confront each other. A damper mechanism 60 is constituted by the combination of a piston member 62 provided on one of the confronting axially movable members 26a, 48a and a cylinder member 61 provided on the other thereof.

Abstract: A clutch disk made of a C/C composite for a wet multi-plate clutch is comprised of a disk body, and a pair of friction layers integral with and on opposite sides of the disk body for sliding contact with clutch plates. A relationship of V.sub.2 >V.sub.1 is established between the porosity V.sub.1 of the disk body and the porosity V.sub.2 of the friction layer, and the porosity V.sub.2 of the friction layer 4 is set in a range of 20%.ltoreq.V.sub.2 .ltoreq.60%, which provides a clutch disk with sufficient strength and excellent sliding characteristics.

Abstract: A cooling structure of a power transmission apparatus is provided. The power transmission apparatus has an electromagnetic clutch including a fixed outer member with an exciting coil and a rotary inner member adapted to be fixed to the outer member by controlling electric energy provided to the exciting coil, and a gear device connected to the inner member of the electromagnetic clutch. A cooling apparatus is positioned between the outer member and a gear case member housing the gear device, for cooling both of the electromagnetic clutch and the gear device concurrently.

Abstract: The apparatus comprises a planetary gear device and a magnetic particle type electromagnet clutch. The planetary gear device has a gear element connected to an input member, another gear element connected to an output member and a remaining other gear element. The electromagnetic clutch has a fixed member provided with a exciting coil and a rotary member adapted to be fixed to the fixed member by controlling intensity of electric current in the exciting coil. The rotary member is connected to the remaining other gear element.

Abstract: An centrifugal friction clutch for an automatic speed changing device to changeover speed change stage automatically in accordance with a change of rotational speed is provided.

Abstract: A swash-plate, plunger-type hydraulic pressure apparatus, which may operate as a hydraulic pump or motor, includes a cylinder block, an annular array of plungers slidably held in the cylinder block, a swash plate, a plurality of shoes angularly movably coupled respectively to the ends of the plungers, and a retainer plate mounted adjacent the swash plate and holding the shoes in slidable contact with the sliding surface. The shoes have respective annular grooves defined in the outer cylindrical surfaces thereof. The retainer plate has a plurality of shoe holding holes defined therein and a like plurality of cutout openings extending from the holes. The shoe holding holes communicate with one of outer and inner circumferential edges of the retainer plate through the cutout openings, respectively. The cutout openings have a width slightly larger than the outside diameter of the annular grooves, whereby the annular grooves can be inserted into the shoe holding holes, respectively, through the cutout openings.

Abstract: A plunger and swash-plate type hydraulic pump or motor with a retainer plate 30 that presses a slidable abutment 22 of each of a plurality of shoe members 20 against a slidably abutting surface 8a of a swash-plate 8 in such a manner that a neck 21 of each shoe member is inserted into each of a plurality of insertion holes 31 of the retainer plate 30. An imaginary center plane C.sub.3 or C.sub.4 of the part of the inner surface of each of the insertion holes 31 which abuts against the outer periphery 21a of the neck 21 is coincident with the center O.sub.2 around which each of the shoe members 20 swings relatively to the plunger 10 in the axial direction of each of the insertion holes 31.

Abstract: A hydraulically operated continuously variable transmission includes a hydraulic pump coupled to an input shaft, a hydraulic motor coupled to an output shaft, a closed hydraulic circuit interconnecting the hydraulic pump and the hydraulic motor, a hydraulic actuator for actuating a controlled member in the closed hydraulic circuit, an auxiliary pump connectable to the closed hydraulic circuit and the hydraulic actuator, a supply oil passage for supplying oil discharged from the auxiliary pump to the hydraulic actuator, and a control valve coupled between the supply oil passage, the closed hydraulic circuit, and an oil tank. The control valve comprises a hydraulic chamber communicating with the supply oil passage, a spring, and a spool disposed between the hydraulic chamber and the spring.

Abstract: A hydraulically operated continuously variable transmission comprises a hydraulic pump and a hydraulic motor having a motor cylinder including an integral tubular member. A distribution disc is coupled to the motor cylinder at one end of the tubular portion and has oil passages communicating with the hydraulic pump and the hydraulic motor. A hollow fixed shaft is inserted in the tubular member, and a distribution ring is axially movably mounted on the fixed shaft and has an end face slidably held against the distribution disc. A mechanical seal assembly includes an annular rotatable seal member rotatably disposed in the tubular member, and an annular fixed seal member axially movably, but nonrotatably, mounted on the fixed shaft.

Abstract: A hydraulically operated continuously variable transmission includes a hydraulic motor coupled to an output shaft and having a motor swash plate and a motor cylinder supporting an annular array of slidable motor plungers held in slidable contact with the motor swash plate, a distribution member integral with the motor cylinder, a hydraulic pump coupled to an input shaft in sliding contact with the distribution member and having a pump swash plate movable with the motor cylinder and a pump cylinder supporting an annular array of slidable pump plungers held in slidable contact with the pump swash plate, a closed hydraulic circuit interconnecting the hydraulic pump and the hydraulic motor, the pump cylinder being coaxially surrounded by the motor cylinder with a hydraulically hermetic chamber defined therebetween, and a replenishing pump operatively coupled to the input shaft and connected to the closed hydraulic circuit through a replenishing oil passage.

Abstract: A hydraulic motor and a hydraulic pump are interconnected by a closed hydraulic circuit. A lubricating chamber is defined around the sliding surfaces of the swash plate and the plungers of at least one of the hydraulic pump and the hydraulic motor. A shuttle valve has two input ports connected to respective oil passages, the shuttle valve being shiftable to connect the one of the oil passages which is of lower oil pressure to the output port of the shuttle valve when the differential pressure between the oil passages is relatively large. A first relief valve is opened to communicate the output port to the lubricating chamber when the oil pressure in the output port exceeds a first pressure level. A second relief valve connected between the first relief valve and the lubricating chamber is opened when the oil pressure between the first relief valve and the lubricating chamber exceeds a second pressure level lower than the first pressure level.

Abstract: A hydraulically operated continuously variable transmission includes a hydraulic pump coupled to an input shaft, a hydraulic motor coupled to an output shaft, a closed hydraulic circuit interconnecting the hydraulic pump and the hydraulic motor, and a control valve coupled to an inlet of the hydraulic pump and openable for discharging working oil from the hydraulic pump when the pressure of oil in the inlet of the hydraulic pump is below a prescribed pressure level. The transmission also includes a hydraulically hermetic chamber defined between the pump and motor cylinders and accommodating therein the pump swash plate and the pump plungers, and oil discharge means disposed in the motor cylinder for discharging oil from the hydraulically hermetic chamber when the pressure of oil in the hydraulically hermetic chamber is below a prescribed pressure level.

Abstract: A continuously variable transmission employing a hydraulic motor and a hydraulic pump that are interconnected by a closed hydraulic circuit. An oil chamber is defined between the pump cylinder of the hydraulic pump and the motor cylinder of the hydraulic motor. A common oil cooling unit is connected through oil passages to the closed hydraulic circuit and the oil chamber for cooling heated oil supplied therefrom. The common oil cooling unit effectively cools the oil from the two sources since the heat developed in the oil from the two sources generally varies inversely during different modes of operation.

Abstract: A hydraulically operated continuously variable transmission for an automobile includes a hydraulic pump coupled to an input shaft and having an outlet port, a hydraulic motor coupled to an output shaft, at least one of the hydraulic pump and the hydraulic motor being of the variable-displacement type, a closed hydraulic circuit interconnecting the hydraulic pump and the hydraulic motor, and a device for selectively making and breaking the hydraulic circuit respectively by opening and closing the outlet port. The device comprises a valve body for closing the outlet port, a valve holder for driving the valve body to selectively open and close the outlet port, and a spring for normally urging the valve body in a direction to close the outlet port, the valve body and the valve holder being held in engagement with each other for relative displacement in directions to open and close the outlet port.

Abstract: A hydraulically operated swash-plate apparatus includes a cylinder block rotatably supported in a case and having a plurality of axial cylinders arranged in an annular pattern, the case having an end plate for bearing a thrust load from the cylinder block, a plurality of plungers received respectively in the cylinders, a swash plate supported in the case by trunnions and slidably held against the free ends of the plungers, an actuator for tilting the swash plate, the plungers being movable into and out of the respective cylinders by a stroke which is variable according to the angle of inclination of the swash plate, a support member by which the trunnions are rotatably supported, and a tension member coupling the end plate and the support member to each other. The apparatus also includes a stopper mounted in the case for engaging a back of the swash plate to limit the maximum angle of inclination of the swash plate.

Abstract: A hydraulically operated continuously variable transmission includes a hydraulic pump coupled to an input shaft, a variable-displacement hydraulic motor coupled to an output shaft, and a closed hydraulic circuit interconnecting the hydraulic pump and the hydraulic motor and including a passage connecting the inlet and outlet ports of the hydraulic pump. A servomotor makes and breaks the hydraulic circuit respectively by opening and closing the outlet port. A clutch valve continuously varies the cross-sectional area of the passage to change the amount of power transmitted between the hydraulic pump and the hydraulic motor. A control system independently controls the servomotor and the clutch valve, the control system being arranged to hold the servomotor in a position to open the outlet port when the clutch valve is opened beyond a prescribed degree.

Abstract: A hydraulically operated, swash-plate apparatus such as a hydraulically operated continuously variable transmission includes a cylinder block rotatably supported in a case and having a plurality of axial cylinders arranged in an annular pattern, plungers received respectively in the cylinders, and a swash plate supported in the case and slidably held against the free ends of the plungers through a shoe therebetween. The plungers are movable into and out of the respective cylinders by a stroke determined by the angle of inclination of the swash plate. The shoe having a body and a sliding surface disposed thereon and slidably held against the swash plate and made of a material having a coefficient of thermal expansion different from that of the body of the shoe. The sliding surface becomes convex at a temperature upon operation of the apparatus.