An oil pump having a pump housing with a suction-side inlet and with a pressure-side first outlet, which is coupled to a first pump chamber, and with a pressure-side second outlet, which is coupled to a second pump chamber having a first pump rotor which is situated in the first pump chamber so as to be rotatable about a first axis, and having a second pump rotor which is situated in the second pump chamber so as to be rotatable about a second axis, wherein the pump rotors are arranged in a plane, oriented substantially perpendicular to the axes of the pump housing and are coupled by way of an external circumferential toothing.

A pump apparatus includes a shaft, a first pump, and a second pump. The first pump includes a first driving gear disposed on the shaft in a first phase and rotatable with the shaft to feed a first operating fluid. The second pump includes a second driving gear disposed on the shaft in a second phase shifted from the first phase. The second driving gear is coaxial with the first driving gear and rotatable with the shaft to feed a second operating fluid.

A two stage pump (2, 4), where the high pressure stage (4) is a gear pump (11, 12), comprises a driving of the other stage (2) by a support shaft (74), mounted in the driven pinion (12), the shaft (74) being driven by the drive shaft (21), by means of a pair of toothed wheels (77, 79) adjacent to the rest of the stage (4), which can allow different rotation speeds between the two stages (2, 4). The support shaft (74) may be supported by stops and hydrodynamic bearings, directly integrated and lubricated in the driven pinion, which make the design lighter and more compact. The shaft (74) and the toothed wheels (77, 79) ingeniously transmit the loads from the stage (2) to the stage (4) in such a way as to cancel out the usual hydraulic loads, stemming from pressure, and mechanical, forces stemming from rotational drivings on the driven pinion (12).

A pump includes a housing, a drive shaft, a centrifugal pump portion having an impeller, and a gear pump portion having first and second gears. The impeller and one of the first and second gears are mounted to the drive shaft to drive the centrifugal pump portion and the gear pump portion at the same rotational speed. The gear pump can be a crescent internal gear (CIG) pump. The drive shaft can be rotated by a magnetic drive. The drive shaft can include a longitudinal bore in fluid communication with a cavity in the magnetic drive and with a discharge of the centrifugal pump portion to circulate working fluid through the magnetic drive to cool the drive. An impeller can be coupled to an inlet of the centrifugal pump portion.

An oil pump having a pump housing with a suction-side inlet and with a pressure-side first outlet, which is coupled to a first pump chamber, and with a pressure-side second outlet, which is coupled to a second pump chamber having a first pump rotor which is situated in the first pump chamber so as to be rotatable about a first axis, and having a second pump rotor which is situated in the second pump chamber so as to be rotatable about a second axis, wherein the pump rotors are arranged in a plane, oriented substantially perpendicular to the axes of the pump housing and are coupled by way of an external circumferential toothing.

A pump system includes a turbine shaft including a turbine disposed thereon to rotate the turbine shaft at a turbine shaft speed due to fluid flow through the turbine, a centrifugal pump directly connected to the turbine shaft and configured to pump hydraulic fluid at the turbine shaft speed, a bleed port disposed downstream of the centrifugal pump, and a valve configured to be fluidly connected to the bleed port and configured to meter flow to the turbine to regulate the turbine shaft speed at least partially as a function of pressure from the bleed port.

A pump device includes a shaft, a first gear pair, a second gear pair, a support pin, and a casing. The first gear pair includes a first driving gear which is disposed on the shaft and is rotatable together with the shaft, and a first driven gear driven by the first driving gear. The second gear pair includes a second driving gear which is disposed on the shaft coaxially with the first driving gear and is rotatable together with the shaft, and a second driven gear driven by the second driving gear and arranged coaxially with the first driven gear. The support pin penetrates the first driven gear and the second driven gear and rotatably supporting the first driven gear and the second driven gear. The casing covers the first gear pair and the second gear pair. The support pin is fitted to the casing to be fixed.

A pump-regulator combination includes first and second pumps, a control valve, first orifice, and pilot valve. The first pump is configured to pump fluid from a tank to a first point. The control valve is configured to control pressure and/or delivery flow at the first point by adjusting a displacement volume of the first pump. The second pump is configured to pump fluid from the tank to a second point, through the first orifice, and back to the tank. A highest load pressure of the actuator is connected to a third point. The pilot valve includes an adjustable second orifice connected to the third point, via a fourth point, and the tank to pass fluid from the actuator to the tank. A pressure at the second point acts to close the second orifice. A pressure of the fourth point acts to adjust the control valve.

A pump device having a vane-type pump has a check valve in a fluid duct which leads from a pressure region to an under-vane region. The check valve blocks in the direction of the pressure region, preventing pressure from escaping from the under-vane region into the pressure region during the start-up of the vane-type pump.

A fluid pump includes a housing. A delivery portion includes a delivery pump element disposed within the housing. A return portion includes a return pump element disposed within the housing. A motor is disposed within the housing that drives the delivery pump element and the return pump element via a drive shaft. The delivery portion is configured to deliver fluid from a reservoir to a drive unit. The return pump element is configured to deliver the fluid from a sump assembly of the drive unit to the reservoir.