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.

An internal gear pump or motor includes inner and outer rotors that mesh together. An internal electric motor or generator may include a stator supported by a support element that passes through bearings of the outer rotor and the inner rotor may act as a rotor of the electric motor or generator. With or without the stator, the support element may support bearings of the inner rotor. The support element may be, for example, an eccentric shaft. Fluids may be supplied via the support element, if present, for cooling, lubrication or to flush a working fluid out of portions of the pump or motor, such as bearings. Flushing may also occur via channels in the housing with or without the presence of the support element. Axial faces of one of a pair of adjacent elements, for example the inner rotor and the outer rotor, may include portions for improved axial sealing and wearing in of the other of the pair. Fluid may enter and exit chambers between the inner and outer rotors by radial ports.

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 fluid pumping device is disclosed. The fluid pumping device includes a housing having a front end and a rear end, a fluid discharge opening in the front end of the housing, a pump assembly, a crank assembly rotatably connected to the pump assembly wherein the crank assembly operates the pump assembly, and a fluid storage reservoir connected to the gear housing from which fluid is drawn into the gear housing to be pumped through the fluid discharge opening.

Compression of water vapour as R718 is disclosed with and without addition of additives as an aqueous solution in rotational displacement machines, i.e. refrigeration, air-conditioning and heat pump technology. To largely avoid over or under-compression, it is proposed for the easiest possible adaptation of the currently effective internal volume ratio as so-called iV value in the displacer that the compressor housing starting from the outlet side with rotor profile length L.sub.R over a length L.sub.iV comprises planar, i.e. flat iV disks (3.sub.j) with the index j for 1?j?n; n is the number of disks; n?1 with a width b.sub.j per iV disk having planar surfaces P.sub.F preferably perpendicular to the neutral axis A.sub.N. The iV disks are displaced in a targeted manner individually by movement control devices (5.sub.j) per iV disk in each case by a distance s.sub.i where 0<s.sub.i?s.sub.j.

A pump for fluid material includes a housing and a rotor member within the housing mounted to rotate between a passageway end plate and a drive end plate each having inward facing cam surfaces. The housing, plates, and rotor member in assembly form a passageway between a passageway cam surface and a first side of the rotor member. This places the passageway's intake opening and discharge opening in communication with each other along the passageway. The rotor member's vane elements are configured to slide laterally and move reciprocally as the rotor member rotates, moving the fluid material being fed into the intake opening, through the passageway, and finally out the discharge opening.

A water pump with a pump body, a chamber defined inside the pump body, and a rotor rotatable inside the chamber around a rotation axis with a plurality of vanes movable along respective radial directions. A tilting stator is arranged inside the chamber in an eccentric position with respect to the rotor. The tilting stator is pivoted at a rotation pin. A ring is interposed between the tilting stator and the rotor and is in contact with a radially inner surface of the tilting stator and with radially outer ends of the vanes. Adjusting members for adjusting the pump displacement are active on the tilting stator to move the tilting stator with respect to the rotor and place the tilting stator in at least one predetermined operating position defined between a maximum eccentricity position and a minimum eccentricity position.

A water pump with a stator, a chamber defined inside the stator, a ring arranged inside said chamber having a radially outer surface in contact with a radially inner surface of the stator, and a rotor arranged inside the ring and rotatable around a rotation axis. The rotor has a plurality of vanes movable along respective radial directions and having respective radially outer ends in contact with a radially inner surface of the ring. The ring is made of a material having a friction coefficient lower than friction coefficient of metal materials.

An internal gear pump or motor includes inner and outer rotors that mesh together. An internal electric motor or generator may include a stator supported by a support element that passes through bearings of the outer rotor and the inner rotor may act as a rotor of the electric motor or generator. With or without the stator, the support element may support bearings of the inner rotor. The support element may be, for example, an eccentric shaft. Fluids may be supplied via the support element, if present, for cooling, lubrication or to flush a working fluid out of portions of the pump or motor, such as bearings. Flushing may also occur via channels in the housing with or without the presence of the support element. Axial faces of one of a pair of adjacent elements, for example the inner rotor and the outer rotor, may include portions for improved axial sealing and wearing in of the other of the pair. Fluid may enter and exit chambers between the inner and outer rotors by radial ports.

An impeller 1 for a pump includes a cylindrical bush 13 rotatably held at an eccentric position within a cylindrical pump housing via a rotating shaft 3 and a plurality of vanes 11 that are fixed to an outer circumferential face of the bush 13 and radially extend to divide the inside of the pump housing into a plurality of compartments 14, each of the vanes 11 being made of a rubber-like elastic material and being formed inclined in a rotational direction of the bush 13 relative to a radial direction from the rotating shaft 3 of the bush 13.