A rotary vane pump including a housing, and a motor. The motor includes a shaft which is coupled to a rotor. The rotor defines a plurality of slots. A plurality of free moving vanes are disposed within the slots. In one example, the rotor is formed from a first material and the plurality of vanes are formed from the first material and impregnated with a second material. The first material can be a carbon material. The second material can be a resin material, an antimony material, a copper material, or a silver material.

A reversible pneumatic vane motor includes a stator housing with a pressure air inlet passage and an exhaust air outlet passage, a cylinder supported in the stator housing, a vane carrying rotor rotatable in the cylinder and forming a clearance seal portion with the cylinder, air communication ports located at opposite sides of the seal portion for supplying motive pressure air or scavenging exhaust air from the cylinder, a primary outlet diametrically opposite the clearance seal portion, and a directional valve for connecting alternatively the air communication ports to the pressure air inlet passage and the exhaust air outlet passage. The motor also includes auxiliary outlet ports which are located between the primary outlet and each one of the air communication ports, and the directional valve includes control parts for opening up and closing, respectively, communication between the auxiliary outlet ports and the atmosphere via the exhaust air outlet passage.

A variable displacement oil pump includes: a variable displacement mechanism that is able to change a discharge amount per rotation of an input shaft. The variable displacement mechanism includes a pump housing, an oil pressure chamber provided in the pump housing, and a capacity adjustment member displaced by oil pressure from the oil pressure chamber. The capacity adjustment member is configured to be operated when receiving control oil pressure that is supplied from a control valve to the oil pressure chamber. The pump housing has an oil release hole that is opened to face the oil pressure chamber and that penetrates a wall section of the pump housing to partially release oil.

An inner wall surface of a pump housing has a slide surface, which is opposite from a joint member and along which an inner rotor is slidable. This slide surface includes an external tooth slide surface and a main body slide surface. External teeth of the inner rotor are slidable along the external tooth slide surface, and a main body of the inner rotor is slidable along the main body slide surface. A surface roughness of the main body slide surface is higher than a surface roughness of the external tooth slide surface.

A variable displacement vane pump includes a notch portion which is a flow path provided to extend from an initiating end of a discharge port towards a terminating end side of a suction port. The notch portion is formed so that a sectional area of the flow path is smaller than a sectional area of the discharge port at the initiating end thereof and that a length of the flow path in a circumferential direction is 1.5 pitches or larger. The terminating end of the suction port is a point where the vane in the suction area last overlaps the suction port. The initiating end of the discharge port is a point where the vane departed from the suction area first overlaps the discharge port. One pitch is a distance defied in the circumferential direction between adjacent vanes of the plurality of vanes.

A variable displacement vane pump includes a notch portion which is a flow path provided to extend from an initiating end of a discharge port towards a terminating end side of a suction port. The notch portion is formed so that a sectional area of the flow path is smaller than a sectional area of the discharge port at the initiating end thereof and that a length of the flow path in a circumferential direction is 1.5 pitches or larger. The terminating end of the suction port is a point where the vane in the suction area last overlaps the suction port. The initiating end of the discharge port is a point where the vane departed from the suction area first overlaps the discharge port. One pitch is a distance defied in the circumferential direction between adjacent vanes of the plurality of vanes.

A fluid delivery system includes a reservoir for storing fluid, a rotary pump having a first pump port and a second pump port, a first fluid conduit connecting the first pump port to the reservoir, and a second fluid conduit connecting the second pump port to the reservoir. The rotary pump rotates in a first delivery direction in a normal mode and in a second delivery direction in an alternative mode. A first valve separates the first pump port from the reservoir when the rotary pump is in its alternative mode, and a second valve separates the second pump port from the reservoir when the rotary pump is in its normal mode.

A variable displacement oil pump is described. The oil pump has pump body connected to an intake channel and to a delivery channel, a rotor capable of rotating inside the pump body about a rotation axis and provided with a plurality of vanes. The oil pump has an oscillating stator arranged in an eccentric position around the rotor and pivoted inside the pump body at a rotation pin. The oil pump has adjustment means for adjusting the displacement of the oil pump which acts on the oscillating stator to displace it with respect to the rotor and position it in at least one predetermined operative position. The adjustment means has first thrusting means configured to exert a first thrusting action on a first outer surface portion of the oscillating stator arranged on a substantially opposite side with respect to the rotation pin taking as a reference the rotor.

A variable displacement oil pump is described. The oil pump has pump body connected to an intake channel and to a delivery channel, a rotor capable of rotating inside the pump body about a rotation axis and provided with a plurality of vanes. The oil pump has an oscillating stator arranged in an eccentric position around the rotor and pivoted inside the pump body at a rotation pin. The oil pump has adjustment means for adjusting the displacement of the oil pump which acts on the oscillating stator to displace it with respect to the rotor and position it in at least one predetermined operative position. The adjustment means has first thrusting means configured to exert a first thrusting action on a first outer surface portion of the oscillating stator arranged on a substantially opposite side with respect to the rotation pin taking as a reference the rotor.

A fluid pump includes a housing; an inlet passage; an outlet conduit; a pumping element within the housing; and a check valve assembly. The check valve assembly includes a valve stem within the outlet conduit such that a flow path is created radially between the outlet conduit and the valve stem, the valve stem moving along a check valve assembly axis between a closed position and an open position. The flow path includes a first restriction which increases velocity of fluid passing through the flow path; a first expansion, downstream of the first restriction, which decreases velocity of fluid passing through the flow path; a second restriction, downstream of the first expansion, which increases velocity of fluid passing through the flow path; and a second expansion, downstream of the second restriction, which decreases velocity of fluid passing through the flow path.