Abstract: A hydraulic oil deterioration ratio estimating apparatus in a vehicle includes a torque converter, an automatic transmission, an oil temperature detector, an engine speed detector, an input shaft rotation speed detector, an output shaft rotation speed detector, and a hydraulic oil deterioration ratio estimator. The hydraulic oil deterioration ratio estimator is configured to estimate a deterioration ratio of hydraulic oil. The hydraulic oil deterioration ratio estimator includes a first thermal deterioration ratio calculator, a second thermal deterioration ratio calculator, a third thermal deterioration ratio calculator, a mechanical deterioration ratio calculator, and a deterioration ratio comparator. The first thermal deterioration ratio calculator is configured to calculate a first thermal deterioration ratio of the hydraulic oil during stoppage of the vehicle based on an estimated value of a change in temperature of the hydraulic oil from the stoppage of the vehicle to start of the vehicle.

Abstract: A hydraulic oil deterioration ratio estimating apparatus in a vehicle includes a torque converter, an automatic transmission, an oil temperature detector, an engine speed detector, an input shaft rotation speed detector, an output shaft rotation speed detector, and a hydraulic oil deterioration ratio estimator. The hydraulic oil deterioration ratio estimator is configured to estimate a deterioration ratio of hydraulic oil. The hydraulic oil deterioration ratio estimator includes a first thermal deterioration ratio calculator, a second thermal deterioration ratio calculator, a third thermal deterioration ratio calculator, a mechanical deterioration ratio calculator, and a deterioration ratio comparator. The first thermal deterioration ratio calculator is configured to calculate a first thermal deterioration ratio of the hydraulic oil during stoppage of the vehicle based on an estimated value of a change in temperature of the hydraulic oil from the stoppage of the vehicle to start of the vehicle.

Abstract: A hydraulic fluid change indicating device for an automatic transmission includes a first deterioration rate calculating unit; a deterioration acceleration coefficient calculating unit; and a thermal hydraulic fluid deterioration calculating unit for calculating a thermal hydraulic fluid deterioration according to the first deterioration rate and the deterioration acceleration coefficient. The device further includes a second deterioration rate calculating unit according to an engine speed, input shaft speed, and output shaft speed; a mechanical hydraulic fluid deterioration calculating unit for calculating a mechanical fluid deterioration according to the second deterioration rate; and a determining unit for determining whether or not the thermal hydraulic fluid deterioration or the mechanical hydraulic fluid deterioration is greater than a predetermined hydraulic fluid change threshold.

Abstract: A hydraulic fluid change indicating device for an automatic transmission includes a first deterioration rate calculating unit; a deterioration acceleration coefficient calculating unit; and a thermal hydraulic fluid deterioration calculating unit for calculating a thermal hydraulic fluid deterioration according to the first deterioration rate and the deterioration acceleration coefficient. The device further includes a second deterioration rate calculating unit according to an engine speed, input shaft speed, and output shaft speed; a mechanical hydraulic fluid deterioration calculating unit for calculating a mechanical fluid deterioration according to the second deterioration rate; and a determining unit for determining whether or not the thermal hydraulic fluid deterioration or the mechanical hydraulic fluid deterioration is greater than a predetermined hydraulic fluid change threshold.

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 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 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 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 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.

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 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 hydraulically hermetic chamber is defined in surrounding relations to at least one of the hydraulic pump and the hydraulic motor. The hydraulically hermetic chamber is connected to a replenshing pump by a relief valve which is openable at a pressure level. A pressure control valve is disposed in a discharge passageway of the hydraulically hermetic chamber and openable at a first pressure level lower than the pressure level for the relief valve. In another embodiment, a second pressure control valve is connected to a junction between the first pressure control valve and the lubricating chamber and openable at a second pressure level lower than the second pressure level.

Abstract: In a hydraulic transmission comprising: an input shaft connected to a flywheel of a crankshaft of an engine through a rotary container of a centrifugal oil filter; and an oil supply pump adapted to be driven by the input shaft, wherein the rotary container has its inside communicating at one side with a discharge port of the supply pump and at the other with a transmission oil circuit, a shock absorbing system characterized: in that a torque absorbing member is interposed between the rotary container connected to the input shaft and a thrust plate fitted rotatably on the outer circumference of the container, the torque absorbing member being adapted to be deformed in response to the relative rotations of the two; and in that the thrust plate is connected the flywheel.