A pump is formed by a housing (10) having an inlet (11) for connection to a source of fluid and an outlet (12) for pumped fluid. A rotor (15) is rotatable within the housing and the inlet (11) and the outlet (12) are spaced apart around the path of the rotor (15) in the housing. The rotor (15) has surfaces (16a, 16b, 16c, 16d) that form, with the housing (10), closed chambers (18a, 18b, 18c, 18d) which travel around the housing (10) to convey fluid from the inlet (11) to the outlet (12). The housing (10) carries a seal (14) that is located between the inlet (11) and the outlet (12) in the direction of travel of the rotor (15). The seal (14) co-operates with the rotor surfaces (16a, 16b, 16c, 16d) as the surfaces (16a, 16b, 16c, 16d) pass between the outlet (12) and the inlet (11) to prevent the formation of a chamber during said passage and so prevent fluid flow from the outlet (12) to the inlet (11). Such a pump is easily and cheaply produced and is particularly useful in medical applications.

A hydraulic pump is described comprising a rotor provided for rotation about a longitudinal axis (X-X) within a housing. The pump comprises a plurality of chambers for pumping a fluid that are provided by longitudinally extending recesses in a circumferential outer surface of the rotor. During use the recesses are moved across a circumferential inner surface of the housing, and in so doing, are moved over an inlet port in the housing to draw fluid into the chamber and then over an outlet port in the housing to discharge the fluid. The hydraulic pump further comprises a roller that is mounted in a longitudinally extending pocket of the housing. The roller is positioned after the outlet port in a direction of the rotor's rotation and is arranged to follow the outer surface of the rotor and seal against each recess as it is drawn past the roller, thereby directing fluid from the chamber into the outlet port.

An outlet gasket which has a gasket structure made of a gasket material, for sealing off a first pressure outlet and a second pressure outlet of a pump, the gasket structure including: a first sealing stay which circumferentially encloses a first fluid passage of the outlet gasket, provided for the first pressure outlet, in a seal in an axial plan view onto the outlet gasket; and a second sealing stay which circumferentially encloses a second fluid passage of the outlet gasket, provided for the second pressure outlet and located laterally next to the first fluid passage, in a seal in the plan view, wherein the gasket structure forms the sealing stays contiguously as a unit, and/or the outlet gasket includes a support structure on which the sealing stays are arranged.

A piston compressor having at least two piston/working space combinations, wherein each piston/working space combination includes at least one fluid inlet channel and one fluid outlet channel, the at least one fluid inlet channel being connected fluidically to a low pressure collecting volume, and/or the at least one fluid outlet channel being connected fluidically to a high pressure collecting volume, wherein the low pressure collecting volume comprises a first part collecting volume and at least one second part collecting volume, the first part collecting volume and the second part collecting volume being connected fluidically to one another via a first overflow channel and at least one second overflow channel, and/or the high pressure collecting volume comprises a first part collecting volume and at least one second part collecting volume.

A piston compressor having at least two piston/working space combinations, wherein each piston/working space combination includes at least one fluid inlet channel and one fluid outlet channel, the at least one fluid inlet channel being connected fluidically to a low pressure collecting volume, and/or the at least one fluid outlet channel being connected fluidically to a high pressure collecting volume, wherein the low pressure collecting volume comprises a first part collecting volume and at least one second part collecting volume, the first part collecting volume and the second part collecting volume being connected fluidically to one another via a first overflow channel and at least one second overflow channel, and/or the high pressure collecting volume comprises a first part collecting volume and at least one second part collecting volume.

A rotary compressor includes a cylinder with a vane slot and a suction port. A vane is slidably disposed in the vane slot. The suction port guides fluid to a compression chamber at one circumferential end of the vane slot. The suction port may be formed in a recessed manner in a radial direction such that at least an end of the suction port in contact with an inner circumferential surface of the cylinder forms a slot shape extending between opposite axial side surfaces of the cylinder. A circumferential length of the suction port is reduced from conventional suction ports as a result of the slot configuration, thereby advancing the compression start angle, and a partition wall portion between the suction port and the vane slot may have elasticity, thereby suppressing close contact between the vane and the vane slot.

A method of casting a rotor using a cavity and core mold allows a longitudinal slot oriented transversely to the axis of rotation to be finish ground to high precision and tight tolerances by casting the slot to have a wider section which extends from the axis to a radius greater than the radii of the hubs of the rotor, and a narrower section which extends from the wider section to the outer surface of the rotor. The geometrical relation of the slot sections to the hubs as cast permits the grinding step to be performed without forming a leak path in either of the hubs.

A method of casting a rotor using a cavity and core mold allows a longitudinal slot oriented transversely to the axis of rotation to be finish ground to high precision and tight tolerances by casting the slot to have a wider section which extends from the axis to a radius greater than the radii of the hubs of the rotor, and a narrower section which extends from the wider section to the outer surface of the rotor. The geometrical relation of the slot sections to the hubs as cast permits the grinding step to be performed without forming a leak path in either of the hubs.

The present disclosure relates to a variable displacement vane pump, in particular for oil, comprising a body having a cavity wherein a movable ring slides in the longitudinal direction over the rotor which rotates around an axis and which is provided with vanes which are radially supported on the inner surface of the fixed ring of fixed eccentricity relative to the rotation axis of the rotor, and with movement means in the longitudinal direction of the movable ring according to a pilot pressure between a position corresponding to the maximum volume of the plurality of chambers, the return elastic spring being in this position at its maximum length, and a predetermined end position corresponding to the minimum volume of the plurality of chambers, the return elastic spring being in this position at its minimum length by action of the displacement in the longitudinal direction of the movable wall which occurs simultaneously to the longitudinal displacement of the plurality of vanes and of the movable ring.

A rotary apparatus comprises a housing, a rotor, and a face seal. The rotor is mounted for rotation relative to the housing. The housing and the rotor cooperate to provide an annular clearance passage therebetween. The face seal is positioned in communication with the clearance passage and establishes a sealed connection between the housing and the rotor to block ingress of debris from the clearance passage. The housing or the rotor comprises a knife partially defining the clearance passage to cut debris that may enter the clearance passage. The rotary apparatus may be used, for example, in a shaft assembly or a final drive.