A hydraulic arrangement for a vehicle transmission includes a hydraulic system path leading to a hydraulic system circuit with a system pressure, a hydraulic lubrication path leading to a hydraulic lubrication circuit with a lubrication pressure, and a branching point connected to an output side of the system and lubrication paths. A variable displacement pump or a pump combination includes at least two fixed displacement pumps hydraulically connected to an input side of the branching point, and a variable displacement pump or at least one fixed displacement pump are hydraulically connected to the output side of the branching point and integrated into the hydraulic system path.

A hydraulic system (1) for a transmission (2) of a motor vehicle (3) includes a pump system (5) with a first pressure outlet (6) and a second pressure outlet (7), a primary circuit (11), a secondary circuit (12), and a system pressure valve (8) that has a system pressure valve slide (9). A secondary pump pressure (P.sub.Psek) output from the second pressure outlet (7) of the pump system (5) is fed to a radial pressure surface (26) of the system pressure valve slide (9), and therefore an axial load based on the secondary pump pressure (P.sub.Psek) acts upon the radial pressure surface (26) of the system pressure valve slide (9) such that the system pressure valve slide (9) tends to move counter to a mechanical preload force out of a first switching position into a second switching position.

A drop-in lube boost valve assembly replaces an OE lube boost valve assembly in a vehicle transmission hydraulic circuit. The OE valve assembly has a valve body with inlet, balancing and outlet ports. The drop-in valve assembly includes a sleeve having inlet and outlet ports, and a bore extending between and fluidically connecting the ports. The drop-in valve ports are spaced from each other. The sleeve includes valve and spring chambers. A valve has a valve face, a sealing portion and a spring stem and is positioned in the sleeve with the sealing portion positioned in the sleeve bore. A spring is positioned on the spring stem. The valve reciprocates in the sleeve between an open state in which the sealing portion does not overlie the sleeve outlet port and a closed state in which the sealing portion overlies and closes off the outlet port.

A hydraulic controlling system including: a cooling and lubricating oil line and a main controlling oil line; an oil-liquid storage; a first pump, wherein an inlet of the first pump is connected to the oil-liquid storage and an outlet of the first pump is connected to the main controlling oil line; a second pump, wherein an inlet of the second pump is connected to the oil-liquid storage and an outlet of the second pump selectively communicates with the cooling and lubricating oil line or the main controlling oil line; and a gearbox-gear-shifting oil line including a gear-shifting-pressure regulating valve, a plurality of gear-shifting-flow-rate controlling valves and a plurality of gear-shifting selector valves. The gear-shifting-flow-rate controlling valves are connected to the main controlling oil line via the gear-shifting-pressure regulating valve. At least some of the gear-shifting-flow-rate controlling valves are connected to a gear-shifting executing piston via the gear-shifting selector valves.

The “factory installed” pressure regulator valve of an automotive transmission is replaced by a pressure regulator valve having two separate valve components conjointly movable together in a bore. A protrusion or protuberance extending from the center of one end of one of the valve components defines a fulcrum which abuts against an adjacent end of the other valve component as the two valve components move conjointly and in direct contact with each other within the bore during operation of the pressure regulator valve. Preferably, an opening is provided in a land in one of the valve components to vent hydraulic fluid (transmission oil) to prevent a pressure build-up in the bore which might separate the two valve components from each other during reciprocating movement of the valve components in the bore.

An automatic transmission comprising a control valve body adapted to control oil flow within the transmission, a torque converter having a torque converter clutch operable in one of an open and an applied condition, a first control circuit between the control valve body and the torque converter and a second control circuit between the control valve body and the torque converter, a first oil path that provides a fluid connection between the first control circuit and the torque converter, a second oil path that provides a fluid connection between the second control circuit and the torque converter, a third oil path that provides a fluid connection between the second control circuit and the torque converter clutch, and an orifice that provides a fluid connection between the second control circuit and the torque converter.

A continuous variable transmission (CVT) hydraulic pressure control device includes: a pressure regulation valve regulating an operation pressure of oil supplied to a friction element of a forward-rearward device; and a switch valve to respectively switch oil discharge paths through which the oil supplied to the friction element is discharged, respectively by a pilot pressure from the pressure regulation valve and an elastic force of a return spring. In particular, the oil discharge paths switched by the switch valve have oil flow resistances different from each other.

An automatic transmission comprising a control valve body adapted to control oil flow within the transmission, a torque converter having a torque converter clutch operable in one of an open and an applied condition, a first control circuit between the control valve body and the torque converter and a second control circuit between the control valve body and the torque converter, a first oil path that provides a fluid connection between the first control circuit and the torque converter, a second oil path that provides a fluid connection between the second control circuit and the torque converter, a third oil path that provides a fluid connection between the second control circuit and the torque converter clutch, and an orifice that provides a fluid connection between the second control circuit and the torque converter.

A hydraulic control apparatus includes an output-side oil passage into which oil from a first oil passage and oil from a second oil passage flow, and a pressure regulating check valve regulating a hydraulic pressure in the second oil passage. The pressure regulating check valve includes first and second elastic portions housed in a spool hole between a valve body and a bottom of the spool hole. A natural length of the second elastic portion is shorter than a distance between the valve body and the bottom when the valve body closes an inflow hole. The second elastic portion applies an elastic force to the valve body in a state in which the valve body opens the inflow hole.

A vehicle power transmission device includes: a continuously variable transmission including a primary pulley, a secondary pulley, and a transmission belt wound between the primary pulley and the secondary pulley; a belt running clutch of hydraulic type for transmitting power to the continuously variable transmission; and a hydraulic control circuit controlling the continuously variable transmission and the belt running clutch. The hydraulic control circuit includes a fail-safe valve switching a communication destination of an oil supply passage for supplying a hydraulic fluid to the belt running clutch to one of a first oil passage supplied with a control hydraulic pressure and a second oil passage supplied with a hydraulic pressure higher than the control hydraulic pressure, the fail-safe valve connecting the oil supply passage with the second oil passage when the fail-safe valve is switched to a failure position. The second oil passage is provided with an orifice.