The example embodiment relates to a pressure measuring unit for determining the oil pressure in a motor vehicle transmission, including a circuit carrier, a pressure sensor, an electrical interface, a mechanical interface and a hydraulic interface. The pressure sensor is electrically connected to the circuit carrier by means of the electrical interface and mechanically connected to the circuit carrier by means of the mechanical interface on the first side of the circuit carrier. The hydraulic interface connecting the pressure measuring unit to a user hydraulic component is arranged on a side of the circuit carrier that is situated opposite the first side, and wherein an opening is arranged in the circuit carrier for pressure equalization between the pressure sensor and the hydraulic interface.

An oil supply device comprises a main pump driven by an engine and capable of supplying oil to an automatic transmission and to a hydraulic control valve, an electric motor, a subsidiary pump driven by the electric motor that raises the pressure of a portion of the oil discharged from the main pump and supplies the oil to the hydraulic control valve, and a motor controller which controls driving of the electric motor on the basis of the pressure of the oil supplied to the automatic transmission. The motor controller implements control to drive the subsidiary pump by the electric motor to raise the pressure of a portion of the oil discharged from the main pump to a prescribed pressure or above and supply the oil to the hydraulic control valve when the pressure of the oil supplied to the automatic transmission is less than the prescribed pressure.

A transmission includes an input shaft coupled to a prime mover, a countershaft, main shaft, and an output shaft, with gears between the countershaft and the main shaft. A shift actuator selectively couples the input shaft to the main shaft by rotatably coupling gears between the countershaft and the main shaft. The shift actuator is mounted on an exterior wall of a housing including the countershaft and the main shaft. An integrated actuator housing includes a single external power access for the shift actuator. A controller interprets controls the shift actuator with actuating and opposing pulses, and interprets a shaft displacement angle, determines if the transmission is in an imminent zero or zero torque region, and performs a transmission operation in response to the transmission in the imminent zero or zero torque region.

An apparatus for controlling an electric oil pump (EOP) includes a controller calculating first revolutions per minute (RPM), second RPM and third RPM, the first RPM being EOP RPM required for control of a brake in a transmission, the second RPM being EOP RPM required for cooling of a plurality of motors, and the third RPM being EOP RPM required for lubrication of the plurality of motors, the controller comparing the second RPM with the third RPM and driving the EOP at an RPM obtained by adding the first RPM to the greater of the second RPM and the third RPM.

The disclosure provides a control device of an automatic transmission for vehicle, which can improve the responsiveness to switching to a reverse stage. The automatic transmission includes: planetary gear mechanisms which transmit the driving force input to an input shaft to an output member; and first to third clutches and first to fourth brakes as engagement mechanisms capable of establishing shift stages by switching a transmission path of the driving force in the planetary gear mechanisms. The control device executes a reverse preparation process for starting engagements of the first and third clutches and the third brake and stopping rotation of the input shaft when the reverse stage is selected when the fourth brake (mechanical engagement mechanism) is in a unidirectional rotation allowed state (first state) and the vehicle is traveling at a vehicle speed greater than a highest vehicle speed at which the reverse stage is establishable.

A hydraulic system for an automatic transmission of a motor vehicle, including a high pressure circuit in which a pressure accumulator, at least one clutch and a gear selector are connected, and comprising a low pressure circuit for cooling the clutch, wherein the high pressure circuit and the low pressure circuit have at least one hydraulic pump that can be driven by an electric motor, and including a control unit that actuates the electric motor of the hydraulic pump when a pressure accumulator charging requirement is detected, wherein the high and low pressure circuits are connected via a bypass line to an integrated accumulator charging valve.

For a hybrid vehicle including an engine, a motor generator, and a belt-type continuously variable transmission, a controller performs a low speed position return expediting control in response to a downshift request accompanying deceleration. During the low speed position return expediting control, the controller increases a differential pressure between a primary pressure and a secondary pressure and cause a downshift toward a lowest speed position transmission ratio by reducing the primary pressure, and further reduces the primary pressure when the secondary pressure becomes greater than or equal to a trigger threshold value during the downshift; and terminates the low speed position return expediting control when an actual secondary pressure decreases to a secondary pressure minimum level. The controller further sets a secondary pressure lower limit higher than the secondary pressure minimum level during the low speed position return expediting control.

A hydraulic system for an automatic transmission of a motor vehicle. A high-pressure circuit, in which a pressure accumulator, at least one clutch, and gear selectors and a hydraulic pump, which can be operated by an electronic control unit and by which the accumulator pressure in the high-pressure circuit can be increased in charging operation. A clutch valve that can be operated by the control unit is arranged in a clutch path between the pressure accumulator and a clutch hydraulic cylinder of the clutch, using which clutch valve a hydraulic pressure applied to the clutch hydraulic cylinder can be adjusted, and a safety valve that can be operated by the control unit is arranged upstream of the clutch valve.

A work vehicle includes an engine, a speed changing apparatus that includes a hydrostatic stepless speed changing mechanism and is configured to subject motive power transmitted from the engine to speed changing and output the motive power, a travelling apparatus configured to travel on the motive power received from the speed changing apparatus, a speed detector configured to detect a speed of the travelling apparatus, a pressure detector configured to detect a hydraulic pressure in a closed circuit of the hydrostatic stepless speed changing mechanism, and a controller.

A method for rocking a vehicle free. The vehicle comprises a drive aggregate (2), a transmission (4), shifting elements (10), and a starting element (5). The rocking free process is carried out as a function of actuation of an accelerator pedal (11) by the driver or a torque delivered by the drive aggregate (2) as a function of the actuation of the accelerator pedal. The shifting element (10) is controlled such that reduced actuation of the accelerator pedal or reduced torque delivered by the drive aggregate (2), reduces a control pressure of the shifting element (10) of the transmission (4) down to a filling pressure or a pressure that corresponds to the filling pressure, and increased actuation of the accelerator pedal or increased torque delivered by the drive aggregate (2), increases the control pressure of the shifting element (10) and the shifting element is operated in a slipping mode.