Methods and systems for a transmission are provided herein. In one example, a hydraulic system is provided that includes a boost pump, a relief valve in fluidic communication with the boost pump and a reservoir, and a plurality of control valves in fluidic communication with the boost pump, positioned downstream of the relief valve, and in fluidic communication with a plurality of hydraulic devices. The hydraulic system further includes a controller designed to actively adjust a position of the relief valve based on an aggregate hydraulic pressure demand of the plurality of hydraulic devices to alter a boost pressure of a hydraulic fluid supplied to the plurality of control valves.

The present invention is a hydraulic pressure control device for an automatic transmission that performs a gear shift by switching between engagement and disengagement of a plurality of friction engagement elements and includes solenoid valves, provided corresponding to the friction engagement elements, respectively, that switches between engagement and disengagement of the friction engagement elements by switching between supply and non-supply of hydraulic pressures to the friction engagement elements, and a control device that switches between supply and non-supply of the hydraulic pressures to the friction engagement elements by supplying a predetermined control current to the solenoid valves, in which the control device supplies a fixation preventing current lower than the control current to at least one of the solenoid valves corresponding to the friction engagement elements in a disengagement state of the plurality of friction engagement elements.

A powertrain system including an engine and transmission is described, and includes a temperature sensor disposed to monitor a hydraulic fluid for the transmission. A method for monitoring the temperature sensor includes monitoring engine operation including engine coolant temperature and monitoring a signal output from the temperature sensor. An indicated temperature slope is determined based upon the signal output from the temperature sensor, and a temperature region associated with the engine coolant temperature is determined. Performance of the temperature sensor is evaluated based upon the indicated temperature slope and minimum and maximum temperature slope thresholds that are associated with the temperature region.

A hydraulic system (HY) for a motor vehicle transmission (G) includes at least one pump (P), two pump output lines (P1, P2) for supplying a first pressure circuit (1) and a second pressure circuit (2), and an electromagnetically actuated, first pressure control valve (EDS1), the inlet (EDS11) of which is connected to the first pressure circuit (1) and the outlet (EDS12) of which is connected to a first control surface (PVC) of a spring-loaded shut-off valve (PV). The shut-off valve (PV) is configured for connecting, in a non-actuated condition, the second pump output line (P2) to the second pressure circuit (2) and, in the condition actuated via the first control surface (PVC), disconnecting the second pump output line (P2) from the second pressure circuit (2). A motor vehicle transmission (G) including such a hydraulic system (HY) and a drive train including such a motor vehicle transmission (G) are also provided.

A hydraulic control device that includes a normally closed first solenoid valve, a first check valve, a failsafe valve, and a second check valve, wherein the first movable member of the first check valve is biased to cut off the communication between the first input port and the first drain port in case of the failure in which no current is applied to the first solenoid valve.

An electromagnetic actuator. The electromagnetic armature includes: an armature movable in an axial direction in an armature space; a magnetic coil for generating a magnetic field to move the armature; an operating element motion-coupled to the armature; and a flux-directing part, disposed at an axial end of the magnetic coil, having a recess which extends in the axial direction and in which the operating element is displaceably disposed, the flux-directing part being embodied in two parts. The flux-directing part is embodiment in two parts from a base part facing toward the armature and a top part facing away from the armature. The operating element is mounted, displaceably in the axial direction, in a first bearing point embodied on the top part and in a second bearing point embodied on the base part.

A hydraulic control system includes a linear solenoid valve, an ON-OFF solenoid valve and a hydraulically-operated frictional engagement device. A first hydraulic pressure is regulated by the linear solenoid valve within a predetermined pressure-regulation control range, and is supplied to the frictional engagement device. In a state in which the frictional engagement device is placed in a predetermined engaged state based on the first hydraulic pressure, a second hydraulic pressure, which is higher than the pressure-regulation control range, is supplied from the ON-OFF solenoid valve to the frictional engagement device, such that the frictional engagement device is placed in a fully engaged state with a high engaging torque based on the second hydraulic pressure.

Methods and systems for a transmission are provided herein. In one example, a hydraulic system is provided that includes a boost pump, a relief valve in fluidic communication with the boost pump and a reservoir, and a plurality of control valves in fluidic communication with the boost pump, positioned downstream of the relief valve, and in fluidic communication with a plurality of hydraulic devices. The hydraulic system further includes a controller designed to actively adjust a position of the relief valve based on an aggregate hydraulic pressure demand of the plurality of hydraulic devices to alter a boost pressure of a hydraulic fluid supplied to the plurality of control valves.

A hydraulic control system includes a linear solenoid valve, an ON-OFF solenoid valve and a hydraulically-operated frictional engagement device. A first hydraulic pressure is regulated by the linear solenoid valve within a predetermined pressure-regulation control range, and is supplied to the frictional engagement device. In a state in which the frictional engagement device is placed in a predetermined engaged state based on the first hydraulic pressure, a second hydraulic pressure, which is higher than the pressure-regulation control range, is supplied from the ON-OFF solenoid valve to the frictional engagement device, such that the frictional engagement device is placed in a fully engaged state with a high engaging torque based on the second hydraulic pressure.

Methods and systems for a transmission are provided herein. In one example, a hydraulic system is provided that includes a boost pump, a relief valve in fluidic communication with the boost pump and a reservoir, and a plurality of control valves in fluidic communication with the boost pump, positioned downstream of the relief valve, and in fluidic communication with a plurality of hydraulic devices. The hydraulic system further includes a controller designed to actively adjust a position of the relief valve based on an aggregate hydraulic pressure demand of the plurality of hydraulic devices to alter a boost pressure of a hydraulic fluid supplied to the plurality of control valves.