Abstract: A modular rotor assembly for a screw pump including a power rotor and an idler rotor having respective first ends adapted to be disposed in a suction side of the screw pump and respective second ends adapted to be disposed in a discharge side of the screw pump, the power rotor including a balance piston adapted to be disposed within a pump housing of the screw pump with a radial clearance between an entire circumference of the balance piston and the pump housing is in a range between 1 micron and 200 microns, wherein the power rotor is provided with a tapered bearing surface configured to define a wedge-shaped, radial gap axially intermediate the power rotor and the idler rotor.

Abstract: A pump includes first and second gears coupled to one-another for rotation about respective axis. The first gear may include a concentrically disposed first hub portion and a plurality of first teeth radially projecting and circumferentially spaced about the first hub portion. A plurality of first recesses are defined by the first hub portion, communicate radially outward, and are circumferentially distributed about the first hub portion between adjacent teeth of the plurality of first teeth.

Abstract: A gerotor pump is provided with a body defining a chamber with cylindrical wall sections and having a fluid inlet and a fluid outlet, and a cover. An internally toothed gear member is supported for rotation within the chamber about a first axis, and has a cylindrical outer wall defining a series of grooves. Each groove has an associated aperture extending through the gear member to an inner surface of the gear member, and is radially positioned between adjacent teeth of the internally toothed gear member. An externally toothed gear member is rotatably supported within the internally toothed gear member about a second axis spaced apart from the first axis, and is coupled for rotation with a drive shaft. The internally toothed gear member and externally toothed gear member cooperate to form a plurality of variable volume pumping chambers therebetween to pump fluid.

Abstract: Fluid-injected screw-type compressor element comprising two co-operating rotors (2 and 3) which are radially and axially bearing-mounted in a housing (1), whereby this housing confines a rotor chamber (4) in which the rotors (2 and 3) are situated and in which a fluid circuit (11) for the injection of a fluid discharges, characterized in that the radial bearing of at least one rotor is formed by the contact of the rotor concerned with the part of the wall of the housing opposite the radial perimeter of the rotor concerned and/or the co-operation with the other rotor and by maximally one additional radial bearing.

Abstract: Disclosed herein is an oscillating vane type pump actuator. The pump actuator of the present invention provides a method of preventing fretting corrosion from being caused on joined surfaces of elements. A cylinder (3c) has a comparatively low radial strength, and each of side covers (1c) and (2c) has a high radial strength. A cylindrical portion (1c-c), (2c-c) is provided on each side cover. Thus, when high pressure of work oil distorts the cylinder into a shape in which the cross-section of the cylinder becomes an ellipse-like shape, the cylindrical portions of the side covers act such that they are distorted in the same shape as that of the cylinder. Further, a passage that always communicates with a low-pressure side working chamber is formed in the contact surfaces between a fixed vane that is fixed to the cylinder and the side covers.

Abstract: A vacuum pump is provided comprising a pumping mechanism, a drive shaft for driving the pumping mechanism and a gear box connected to the drive shaft for rotating the drive shaft. Pressure control means are provided to define a path to allow fluid to flow from the pumping mechanism to the gear box in order to reduce the pressure difference therebetween. A reservoir is located within this path for collecting oil passing along the drive shaft from the gear box towards the pumping mechanism. In use, this enables pressurized fluid flowing from the pumping mechanism towards the gear box to urge oil which has collected in the reservoir, towards the gear box.

Abstract: A hydraulic motor receives pressurized fluid from a source controlled by a human operator to convert the energy in the hydraulic fluid to a rotational output to propel a drive wheel of a machine. The hydraulic motor includes an end cover, a manifold, a drive assembly, a wear plate, a housing, and an output assembly. The drive assembly includes a rotor with external teeth and a stator with internal teeth formed by rollers having end faces. The pressurized fluid from the source flows through the manifold to the drive assembly and causes rotational and orbital movement of the rotor relative to the stator. The rotational movement of the rotor is transmitted to the drive wheel by the output assembly. A first set of anti-cogging passages and a second set of anti-cogging passages communicate fluid pressure to the end faces in timed relationship to reduce cogging or detenting of the rotational output of the motor.

Abstract: A pump comprises a housing and a pump unit arranged therein. The pump unit comprises a first and a second thrust plate and a ring arranged therebetween and having a through opening. The ring rests on the two thrust plates at least at an outer peripheral region thereof, and a pressure chamber is formed between the second thrust plate and the housing. A spacer supports the first thrust plate at a distance from the housing, and the spacer is associated at least in part with a radially inner surface area of the first thrust plate opposite the through opening. This allows deformation of the first thrust plate under operational pressure so as to hinder formation of a gap between the thrust plate and the pump insert.

Abstract: A gear pump is hydrostatically balanced by providing a plurality of coupling passages connecting diametrically opposed spaces formed between teeth of the gears. The coupling passages form pressure balancing fluid paths which serve to eliminate pressure differences between the diametrically opposed spaces. Additionally disclosed are balancing pistons which act on spindles supporting the gears. The balancing pistons are aligned to oppose resultant of the remaining forces. Additionally discloses is an eductor motor positioned within a fluid reservoir and connected for driving the gears.

Abstract: In a generator-receiver for power transmission, side plates are molded on an insert with a good coefficient of friction whose outer face is flush with the inner face of each side plate and which comprises two circular parts joined by a bi-concave joint, the insert comprising grooves in each of which the plastic material constituting the side plates penetrates to form a bead in which each cavity is formed.

Abstract: The roller-vane hydraulic machine comprises a hollow casing (1) having working fluid inlet and outlet passages (2, 3). The casing (1) is provided with hollows opening into the space of the casing (1), said hollows accommodating rollers (4) interacting with a rotor (5) located inside of the casing (1). The casing (1) is provided with vanes (6) which, together with the casing (1) form a working space (7) divided by the rollers (4) into larger and smaller inter-roller chambers (8, 9) intercommunicated in pairs by hydraulic relief passages (14, 15). The rollers (4) have slots for the passage of the vanes (6) of the rotor (5). The larger and smaller inter-roller chambers (8, 9) are intercommunicated in pairs by passages (14, 15, 16, 17) in the casing (1).

Abstract: Hydraulic generator-receiver with needle bearings (123) on the driving gear (9) and providing for play compensation between the end plates (21, 22) and the envelope (36), a leak return and a better supply of the pressure zone (34).

Abstract: Hydraulic gear-driven rotary machine (pump or motor) in which the gears are free-floating with no supporting shaft or bearings. Their internal ducts rotate, providing a commutation with the stator ducts. This maintains the hydraulic equilibrium of the gears. A hydrostatic compensating device on the faces of the gears and on their toothing assures internal tightness. The hydraulic gear-driven rotary machine is suitable for operation at very high pressure with hydraulic equilibrium and internal tightness.

Abstract: A scroll-type fluid apparatus including an orbiting scroll member, a stationary scroll member, and a plurality of pockets formed in at least one of the orbiting scroll member and the stationary scroll member to cooperate with the other scroll member for confining liquid therein. When an axially urging force is ecerted on the orbiting scroll member, a liquid pressure commensurate with the axially urging force is produced in the pockets, so that such liquid pressure cancels out a biased axially urging force (moment) exerted on the orbiting scroll member.

Abstract: A scroll-type fluid machine is provided with a plurality of liquid-confining pockets formed in the sliding surface of the end member of either one of orbiting and stationary scrolls. In operation, a high liquid pressure is generated in the pocket or pockets positioned in the region where a localized high axial urging force is exerted during operation, so that the localized high axial urging force acting on the two scrolls is partially or fully negated.

Abstract: A rotary piston engine comprising a stator and a rotor including piston slides in the rotor, and working chambers between the rotor and the stator wherein movable parts are provided in the stator for adjusting the volume of the working chambers.