A delivery device for a motor vehicle for delivering oil from an oil sump to a lubricating oil circuit of internal combustion engine has, as an oil pump, a double-stroke vane-type pump with positive guidance of vanes. A direct drive of the vane-type pump by means of the internal combustion engine is configured for an operating point P2. An increased or reduced oil demand is compensated by means of an activatable electric drive. A compact oil pump of very small dimensions may thus be used.

In a compression unit, an upper compression unit suction tube is connected to an upper suction hole of an upper cylinder, and a lower compression unit suction tube is connected to a lower suction hole of a lower cylinder. In an accumulator shell of an accumulator vessel, an accumulator suction tube, an upper gas-liquid separation tube, and a lower gas-liquid separation tube penetrate a side wall of the accumulator shell, and are fixed by welding to a first through hole, a second through hole, and a third through hole of the accumulator shell, respectively. The upper gas-liquid separation tube is connected to the upper compression unit suction tube via an upper connecting tube outside the accumulator shell. The lower gas-liquid separation tube is connected to the lower compression unit suction tube via a lower connecting tube outside the accumulator shell.

In a compression unit, an upper compression unit suction tube is connected to an upper suction hole of an upper cylinder, and a lower compression unit suction tube is connected to a lower suction hole of a lower cylinder. In an accumulator shell of an accumulator vessel, an accumulator suction tube, an upper gas-liquid separation tube, and a lower gas-liquid separation tube penetrate a side wall of the accumulator shell, and are fixed by welding to a first through hole, a second through hole, and a third through hole of the accumulator shell, respectively. The upper gas-liquid separation tube is connected to the upper compression unit suction tube via an upper connecting tube outside the accumulator shell. The lower gas-liquid separation tube is connected to the lower compression unit suction tube via a lower connecting tube outside the accumulator shell.

A water pump for a marine engine includes a cap covering an internal cavity of the pump's housing when the pump is operating. The cap functions as a tool to remove a damaged or worn impeller from inside the internal cavity. A threaded hub of the cap engages internal threads of the impeller to assist a user in removing the impeller for replacement. A cap lock ring threaded onto the pump housing retains the cap over the internal cavity. A rotatable drive shaft has splines which mate with a splined portion of the impeller to rotate the impeller. The cap lock ring is disengaged from the housing and the cap removed to enable a person to use the threaded hub of the cap to remove the impeller.

A delivery device for a motor vehicle for delivering oil from an oil sump to a lubricating oil circuit of internal combustion engine has, as an oil pump, a double-stroke vane-type pump with positive guidance of vanes. A direct drive of the vane-type pump by means of the internal combustion engine is configured for an operating point P2. An increased or reduced oil demand is compensated by means of an activatable electric drive. A compact oil pump of very small dimensions may thus be used.

A device usable as an impeller has a plurality of vanes rotating eccentrically about a shaft. Eccentric rotation is enabled by a cam mounted on the shaft. The vanes are received within slots in a rotor which surrounds the shaft and rotates about an axis coaxial with the shaft. The rotor rotates within a housing having a cylindrical surface facing the rotor. The surface is eccentric to the shaft. The vanes execute reciprocal motion upon rotation of the rotor. The vane motion is constrained so that the edges of the vanes remain proximate to the cylindrical surface during rotation.

A device usable as an impeller has a plurality of vanes rotating eccentrically about a shaft. Eccentric rotation is enabled by a cam mounted on the shaft. The vanes are received within slots in a rotor which surrounds the shaft and rotates about an axis coaxial with the shaft. The rotor rotates within a housing having a cylindrical surface facing the rotor. The surface is eccentric to the shaft. The vanes execute reciprocal motion upon rotation of the rotor. The vane motion is constrained so that the edges of the vanes remain proximate to the cylindrical surface during rotation.

An oil pump includes: an annular stator (2) having coils (22); a cylindrical outer rotor (3) having a plurality of permanent magnets (24); an inner rotor (4) positioned eccentrically to an inner peripheral side of the outer rotor (3); six linkage plates (5) which link between the outer rotor (3) and the inner rotor (4); and a drive shaft (6) on which the inner rotor (4) is attached. A pump action is obtained by rotating the outer rotor (3) and the inner rotor (action is obtained by rotating the outer rotor (3) and the inner rotor (4). Each of linkage plates (5) has a symmetrical cross sectional shape. A torque transmission is possible in the same way even if the outer rotor (3) is at a drive side and even if the inner rotor (4) is at the drive side.