A fluid pumping system for a vehicle having an internal combustion engine comprises a housing, an electric motor, a rotatable first input adapted to be driven by the internal combustion engine, a rotatable second input driven by the electric motor, and a pump. The pump includes a drum selectively rotated about a drum axis of rotation by one of the first input and the second input, and a pump rotor selectively rotated by the other of the first input and the second input. The drum includes a cam ring having a cavity in receipt of the pump rotor. The drum includes a first fluid inlet port and a second fluid inlet port on opposite sides of the drum such that fluid entering the cavity through the first and second fluid ports flows axially in a direction parallel to the drum axis of rotation. The drum includes a radially extending outlet port such that pumped fluid flows radially out of the cavity. The housing contains the electric motor and the pump.

A fluid pumping system comprises a housing, an electric motor, a rotatable first input, a rotatable second input driven by the electric motor, a gerotor including an inner rotor, an outer rotor; and a cam ring in sliding receipt of the outer rotor. The cam ring is selectively rotatable by one of the first input and the second input. The inner rotor is rotatable by the other of the first input and the second input. The housing includes a first fluid inlet passage on a first side of the cam ring and a second fluid inlet passage on an opposite side of the cam ring. Fluid entering a cavity between the inner rotor and the outer rotor flows parallel to the axis of rotation of the first input. The cam ring includes a radially extending outlet port and pumped fluid flows radially out of the cavity.

A fluid pumping system comprises a housing, an electric motor, a rotatable first input, a rotatable second input driven by the electric motor, a gerotor including an inner rotor, an outer rotor; and a cam ring in sliding receipt of the outer rotor. The cam ring is selectively rotatable by one of the first input and the second input. The inner rotor is rotatable by the other of the first input and the second input. The housing includes a first fluid inlet passage on a first side of the cam ring and a second fluid inlet passage on an opposite side of the cam ring. Fluid entering a cavity between the inner rotor and the outer rotor flows parallel to the axis of rotation of the first input. The cam ring includes a radially extending outlet port and pumped fluid flows radially out of the cavity.

A fluid pumping system for a vehicle having an internal combustion engine comprises a housing, an electric motor, a rotatable first input adapted to be driven by the internal combustion engine, a rotatable second input driven by the electric motor, and a pump. The pump includes a drum selectively rotated about a drum axis of rotation by one of the first input and the second input, and a pump rotor selectively rotated by the other of the first input and the second input. The drum includes a cam ring having a cavity in receipt of the pump rotor. The drum includes a first fluid inlet port and a second fluid inlet port on opposite sides of the drum such that fluid entering the cavity through the first and second fluid ports flows axially in a direction parallel to the drum axis of rotation. The drum includes a radially extending outlet port such that pumped fluid flows radially out of the cavity. The housing contains the electric motor and the pump.

A screw compressor includes a casing, a screw rotor, a discharge passage, and at least one muffler space. The casing includes a cylindrically-shaped cylinder, a main body surrounding a vicinity of the cylinder, and a high-pressure fluid passage provided between the main body and the cylinder. The screw rotor includes a plurality of helical grooves. The screw rotor is inserted into the cylinder to define fluid chambers. A fluid is sucked into the fluid chambers to compress the fluid. The discharge passage is disposed in the casing. The discharge passage guides the fluid that has been discharged from the fluid chambers to the high-pressure fluid passage. The at least one muffler space is disposed in the casing. The at least one muffler space communicates with the discharge passage so as to reduce a pressure fluctuation of the fluid flowing from the discharge passage to the high-pressure fluid passage.

An oil pump driving device includes an oil pump to be driven by either of an engine and an electric motor, and is short in axial dimension. The oil pump driving device includes a first one-way clutch for transmitting motive power from the engine only in one direction, and a second one-way clutch for transmitting motive power from the electric motor only in the above one direction. The first one-way clutch is disposed within an opening formed in a partition wall of a transmission case. The oil pump includes a rotor having an inner peripheral portion defining a hollow space. The second one-way clutch is disposed inside of the inner peripheral portion of the rotor.

A screw compressor includes a casing, a screw rotor, a discharge passage, and at least one muffler space. The casing includes a cylindrically-shaped cylinder, a main body surrounding a vicinity of the cylinder, and a high-pressure fluid passage provided between the main body and the cylinder. The screw rotor includes a plurality of helical grooves. The screw rotor is inserted into the cylinder to define fluid chambers. A fluid is sucked into the fluid chambers to compress the fluid. The discharge passage is disposed in the casing. The discharge passage guides the fluid that has been discharged from the fluid chambers to the high-pressure fluid passage. The at least one muffler space is disposed in the casing. The at least one muffler space communicates with the discharge passage so as to reduce a pressure fluctuation of the fluid flowing from the discharge passage to the high-pressure fluid passage.

An oil pump driving device of which the oil pump can be driven by either of an engine and an electric motor, and which is short in axial dimension. The oil pump driving device includes a first one-way clutch for transmitting motive power from the engine only in one direction, and a second one-way clutch for transmitting motive power from the electric motor only in the above one direction. The first one-way clutch is disposed within an opening formed in a partition wall of a transmission case. The oil pump includes a rotor having an inner peripheral portion defining a hollow space. The second one-way clutch is disposed inside of the inner peripheral portion of the rotor.

A pumping device for pumping oil in a transmission system of a hybrid drive for a motor vehicle has an oil pump and a direct drive for driving the rotor and an electric drive for driving a rotor part that surrounds the rotor. A stationary housing surrounds the rotor part and has an inlet connection and an outlet connection of the oil pump. The oil pump allows a selective drive via the direct drive or the electric drive in a simple manner.

An air compressor includes an internal combustion engine for driving an air compressing part that generates compressed air, which is stored in an air-storage tank. At a point in time when the air pressure inside the air-storage tank has increased to a first set pressure, the supply of fuel to the engine is cut off, thereby stopping the engine and the combustion of fuel. At a point in time when the air pressure inside the air-storage tank has decreased from the first set pressure to a second set pressure, a starter motor is started up to resume the operation of the engine.