A device for protecting an electric pump against overpressures, which comprises a main body which forms a cavity with an axis of extension which is substantially parallel to an axis of extension of the main body and a flow control element which can slide in the cavity along the axis of extension of the cavity between a closed position, in which the flow control element affects an inlet of the cavity which can be connected fluidically to a delivery port of an electric pump, and an open position, in which the flow control element clears at least partially the inlet so as to place it in fluidic connection with an outlet of said cavity, elastic means designed to push the flow control element in response to the pressure that is present in the delivery port.

A board surface of a control board is disposed on an outward side of a motor in a radial direction in a posture along an axial direction. A rotation angle sensor is disposed on a rear side of a control board in the axial direction. A power supply input portion on the control board is disposed in an end portion on the rear side in the axial direction. A main body of a motor includes the control board and a wiring assembly electrically connecting a connector and the rotation angle sensor to each other. The wiring assembly includes a power supply input wiring, a sensor wiring, and a wiring holder holding the power supply input wiring and the sensor wiring.

A board surface of a control board is disposed on an outward side of a motor in a radial direction in a posture along an axial direction. A rotation angle sensor is disposed on a rear side of a control board in the axial direction. A power supply input portion on the control board is disposed in an end portion on the rear side in the axial direction. A main body of a motor includes the control board and a wiring assembly electrically connecting a connector and the rotation angle sensor to each other. The wiring assembly includes a power supply input wiring, a sensor wiring, and a wiring holder holding the power supply input wiring and the sensor wiring.

Variable displacement pump has first control hydraulic chamber 21 giving force to cam ring 5 in direction that decreases volume variation of each pump chamber 13 by internal pressure, second control hydraulic chamber 22 giving force to cam ring in direction that increases volume variation of each pump chamber by internal pressure, first seal surface 44 formed on both end surfaces of cam ring, which are in sliding-contact with both opposing inside surfaces of pump body 1 and cover member 2, and sealing gap between each pump chamber and first control hydraulic chamber, and second seal surface 45 sealing gap between each pump chamber and second control hydraulic chamber at outlet section side. Radial direction width W2 of second seal surface is greater than that W1 of first seal surface. Increase in weight of the pump can be suppressed while suppressing increase in pump control pressure against intention of control.

A fuel flow control assembly for an aircraft engine. The assembly includes a gear arrangement having a shaft. Also included is a bearing structure operatively coupled to each shaft. Further included is a pressure pad disposed adjacent the bearing structure, the pressure pad having a radially extending port for receiving a fuel flow. Yet further included is a flow metering device in flow communication with the port of the pressure pad to restrict the fuel flow at a low pressure operating condition and open the port to increase the fuel flow at a high pressure operating condition.

A fuel flow control assembly for an aircraft engine. The assembly includes a gear arrangement having a shaft. Also included is a bearing structure operatively coupled to each shaft. Further included is a pressure pad disposed adjacent the bearing structure, the pressure pad having a radially extending port for receiving a fuel flow. Yet further included is a flow metering device in flow communication with the port of the pressure pad to restrict the fuel flow at a low pressure operating condition and open the port to increase the fuel flow at a high pressure operating condition.

The invention concerns a method for operating a gear pump, in particular for delivering engine oil in an oil circuit of a vehicle, wherein a delivery device is provided with at least two gear wheels, in particular with external toothing or configured as spur gears and arranged in a housing, wherein by means of the gear wheels a fluid to be conveyed can be delivered starting from at least one housing inlet through to at least one housing outlet, and wherein the gear wheels are arranged behind each other viewed in the axial direction (x). According to the invention, an adjustment device is provided, by means of which the gear wheels can be twisted and/or displaced relative to each other depending on the pressure conditions inside the housing, in particular depending on the vacuum pressure at the housing inlet and/or depending on the fluid back-pressure at the housing outlet.

The invention concerns a method for operating a gear pump, in particular for delivering engine oil in an oil circuit of a vehicle, wherein a delivery device is provided with at least two gear wheels, in particular with external toothing or configured as spur gears and arranged in a housing, wherein by means of the gear wheels a fluid to be conveyed can be delivered starting from at least one housing inlet through to at least one housing outlet, and wherein the gear wheels are arranged behind each other viewed in the axial direction (x). According to the invention, an adjustment device is provided, by means of which the gear wheels can be twisted and/or displaced relative to each other depending on the pressure conditions inside the housing, in particular depending on the vacuum pressure at the housing inlet and/or depending on the fluid back-pressure at the housing outlet.

Methods and apparatus pertaining to positive displacement pumps, and further to hydraulic actuation systems. In some embodiments the pumps are gear pumps with bi-directional operation. In some embodiments the actuation system includes a motor-driven, reversible operation gear pump providing fluid under pressure to a rod and cylinder.

Methods and apparatus pertaining to positive displacement pumps, and further to hydraulic actuation systems. In some embodiments the pumps are gear pumps with bi-directional operation. In some embodiments the actuation system includes a motor-driven, reversible operation gear pump providing fluid under pressure to a rod and cylinder.