Abstract: A variable displacement vane pump, including a pump body, a driving shaft, a rotor, a cam ring swingable around a swing fulcrum, first and second support members on opposite axial sides of the cam ring, a suction port and a discharge port disposed on at least one of the support members, a seal dividing a space on an outer circumferential side of the cam ring into a first fluid pressure chamber defined in a direction in which the cam ring is swung to cause increase in a flow rate of a working fluid discharged, and a second fluid pressure chamber defined in a direction in which the cam ring is swung to cause decrease in the flow rate of the working fluid discharged, and a plunger biasing the cam ring from a side of the second fluid pressure chamber toward a side of the first fluid pressure chamber.

Abstract: A variable displacement vane pump, including a pump body, a driving shaft, a rotor, a cam ring swingable around a swing fulcrum, first and second support members on opposite axial sides of the cam ring, a suction port and a discharge port disposed on at least one of the support members, a seal dividing a space on an outer circumferential side of the cam ring into a first fluid pressure chamber defined in a direction in which the cam ring is swung to cause increase in a flow rate of a working fluid discharged, and a second fluid pressure chamber defined in a direction in which the cam ring is swung to cause decrease in the flow rate of the working fluid discharged, and a plunger biasing the cam ring from a side of the second fluid pressure chamber toward a side of the first fluid pressure chamber.

Abstract: In a fluid control valve, a valve spool doubling as a plunger of a solenoid is slidably installed on a shaft member, i.e., the valve spool and the shaft member are joined by providing therebetween an annular clearance. The shaft member is formed with three or more pressure chambers and radial restriction holes in constant communication with the pressure chambers. The pressure chambers and the radial restriction holes are arranged at equal circumferential intervals and in constant communication with an outside pressure source so that the annular clearance is maintained uniform, i.e., the valve spool is self-centered relative to the shaft member by the effect of the fluid pressure supplied to the pressure chambers at all times.

Abstract: A variable displacement radial piston pump includes a plurality of pump sections which are grouped into two. A first group of pump sections are communicable through a first discharge passage with a third discharge passage. A second group of pump sections are communicable through a second discharge passage with the third discharge passage. A control valve is provided for selectively supplying discharge from said first and second groups of pump sections to the third discharge passage and thereby stepwisely varying the discharge through the third discharge passage.

Abstract: A transmission belt comprises a plurality of chains and a plurality of load blocks. For lateral insertion of the plurality of chains, each of the load blocks including chain receiving portions which open laterally to allow the lateral insertion. Link plates of each chain include concaves for receiving chain receiving portion defining edges to provide drive connection between the chain and the load blocks via the chain receiving portions.

Abstract: According to a hydraulic pressure control system for a continuously variable transmission embodying the present invention, a hydraulic fluid pressure supplied to pulleys is increased temporarily during a transient period where the transmission upshifts from a reduction ratio to a smaller reduction ratio as a result of a predetermined movement of a manual selector valve. The level of the hydraulic fluid pressure is allowed to return to the previous low level after the transient period.

Abstract: A power transmission belt adapted for use in a pulley transmission, comprises a plurality of chains which are arranged in parallel with their pins of each chain positioned out of alignment with the pins of the adjacent chain, and a plurality of load blocks surrounding said plurality of chains. The load blocks functions to provide positive interference among vibrations of the chains so that the amplitude of vibration of the whole assembly is reduced.

Abstract: After the throttle opening degree has exceeded a predetermined value, a target value in engine speed that varies in correspondance with the throttle opening degree is modified to vary in a second pattern whereby the continuously variable transmission is shifted to a predetermined reduction ratio and then kept operating at the predetermined reduction ratio so as to allow the engine speed to increase with the variation in vehicle speed, thus providing an increased acceleration feel.

Abstract: The invention provides an apparatus wherein a parameter indicative of the actual position of a shift actuator is reset periodically when the transmission shift to the largest reduction ratio by such operation is prevented when the vehicle speed is greater than a predetermined vehicle speed value, such as 10 km/h.

Abstract: A control device for an automatic transmission comprises an electromagnetic valve that is subject to pulse duty factor control and generates an adjustment pressure variable in a first pattern after a rod of a shift operation mechanism has moved into an overstroke range beyond a maximum reduction ratio position. The adjustment pressure is variable in a second pattern when the rod fails to move into the overstroke range. An adjustment pressure change-over valve is formed integral with the rod and applies the adjustment pressure to a servo actuating pressure regulator valve (i.e., a throttle valve) when the motor vehicle is at a standstill and the engine idles so as to effect a creep torque control. When the motor vehicle starts moving at a speed above a certain vehicle speed, the adjustment pressure change-over valve applies the adjustment pressure to a lock-up control valve, thereby to effect a lock-up control.

Abstract: In a line pressure control device for a hydraulic control system of an automatic transmission, a vacuum diaphram unit is constructed to apply upon a valve spool of a throttle valve or a regulator valve such a force that reduces with increasing intake manifold vacuum when the intake manifold vacuum is lower than a first predetermined value and such a force that increases with increasing intake manifold vacuum when the intake manifold vacuum is higher than a second predetermined value.

Abstract: A fluid pressure control valve for a hydraulic actuator has a valve body having a valve bore and a fluid port for discharging a fluid toward the hydraulic actuator, and a spool slidably received in the valve bore. The spool has a cylindrical spool section slidably fitted in the valve bore for closing the fluid port and a tapered spool section having a conical shape for opening the fluid port through annular open clearance of a variable area between the concial surface of the spool and the cylindrical surface of the valve bore. Between the cylindrical ad tapered spool sections, there is formed an annular groove or an annular face forming a step for preventing particles of dust suspended in the fluid from being bitten between the tapered spool section and the cylindrical surface of the valve bore by traping the particles.

Abstract: A hydraulic control system is provided wherein a predetermined delay is provided by controlling the flow of fluid from or to frictional element which contributes to shifting into a neutral state within the transmission. With this delay, the engine can sustain rotational speed necessary for restarting upon resumption of fuel supply even after the manual valve is shifted to the neutral state during running condition of an automotive vehicle where the fuel supply to the engine is interrupted.

Abstract: The method features in that the speed at which a shift actuator operates in effecting an upshifting is slower than the speed at which the shift actuator operates in effecting a downshifting.

Abstract: The reduction ratio of a continuously variable transmission is controlled by a stepper motor. The stepper motor is controlled such that each of rotary positions thereof corresponds uniquely to a desired optimum reduction ratio indicative signal indicative of a desired optimum reduction ratio. The desired optimum reduction ratio indicative signal is generated for operating condition of an automotive vehicle.

Abstract: A method and an apparatus controls a reduction ratio of a continuously variable transmission of an automotive vehicle, wherein the reduction ratio is increased when the depression degree of the accelerator pedal is increased rapidly for ensuring quick acceleration. When the depression degree of the accelerator pedal is decreased rapidly, the reduction ratio is held for a predetermined period of time. Under this condition, the reduction ratio may be controlled to accomplish a predetermined deceleration.

Abstract: A method and an apparatus for controlling the reduction ratio of a continuously variable transmission are disclosed wherein normally the reduction ratio is controlled in response to a desired optimum reduction ratio indicative signal obtained by retrieving the data stored in a memory versus engine load and vehicle speed, but when more vehicle acceleration is needed, the reduction ratio is controlled by a corrected desired optimum reduction ratio indicative signal to increase the reduction ratio.

Abstract: A continuously variable V-belt transmission has a change-direction gearing upstream of a drive pulley, and a hydraulic control system. The hydraulic control system comprises a shift control valve for controlling the distribution of fluid pressure between the drive and driven pulleys, a pitot tube for generating an engine revolution speed indicative signal fluid pressure, a pitot tube for generating a drive pulley revolution speed indicative signal fluid pressure indicative of not only of a revolution speed of the drive pulley in the forward direction but also of a revolution speed of the drive pulley in the reverse direction, and a shift prohibiting valve for prohibiting the supply of fluid pressure to at least one of the cylinder chambers of the drive and driven pulley until a difference between the engine revolution speed indicative signal oil pressure and the drive pulley revolution speed indicative oil pressure is less than a predetermined value.

Abstract: A control system for a hydraulic clutch comprises a starting valve and a complete engagement control valve coupled with the starting valve. The starting valve supplies to the clutch a regulated fluid pressure which is elevated in accordance with a revolution speed of an engine when it is in a start fluid pressure regulating state and which is higher than the regulated fluid pressure provided in said start fluid pressure regulating state when it is in said complete engagement fluid pressure regulating state when it is in a complete engagement fluid pressure regulating state. The complete engagement control valve shifts the starting valve from the start fluid pressure regulating state to the complete engagement fluid pressure regulating state when the vehicle speed exceeds a complete engagement vehicle speed.

Abstract: A continuously variable transmission includes a V-belt running over a drive pulley and a driven pulley. Upon rapid shifting in reduction ratio, a line pressure is increased temporarily to provide a proper V-belt gripping force to prevent slipping of the V-belt.