Abstract: In one embodiment, an annular groove and an elastic portion are formed at an end portion of a main bearing on a side facing a cylinder chamber. An annular groove and an elastic portion is formed at an end portion of the sub-bearing on a side facing the cylinder chamber. A depth of the annular groove of the main bearing is formed larger than that of the sub-bearing. An outer peripheral surface of the elastic portion of the main bearing is formed in a straight shape so that thicknesses of a base portion and a tip portion of the elastic portion are the same. An outer peripheral surface of the elastic portion of the sub-bearing is formed in a tapered shape so that a thicknesses of a base portion of the elastic portion is larger than that of a tip portion of the elastic portion.

Abstract: A variable displacement lubricant pump for providing a pressurized lubricant for an internal combustion engine includes a shiftable control ring. The control ring comprises a plurality of pump chambers and a pressure relief valve. The plurality of pump chambers rotate through a charge zone and a discharge zone. A pump rotor comprises radially slidable vanes. The pump rotor rotates in the control ring. A pretensioning element pushes the control ring to a high pumping volume direction. A first control chamber pushes the control ring to a low pumping volume direction. A second control chamber pushes the control ring to the high pumping volume direction. A pump outlet is connected to the first control chamber. A throttle valve connects the first control chamber with the second control chamber. The pressure relief valve of the control ring connects the discharge zone to the second control chamber.

Abstract: A device that enhances compressor efficiency by reducing pressure losses in a discharge muffler space into which is discharged a refrigerant compressed by a compression unit. A low-stage discharge muffler space is formed in the shape of a ring around a drive shaft. In the low-stage discharge muffler space, a communication port flow guide is provided so as to cover a predetermined area of an opening of a communication port from a side of a flow path in a reverse direction out of two flow paths in different directions around the drive shaft from a discharge port through which is discharged the refrigerant compressed by a low-stage compression unit to the communication port through which the refrigerant flows out. The communication port flow guide transforms a direction of a flow into a direction of a connecting flow path.

Abstract: A fluid pump includes a housing that defines a suction chamber, a discharge chamber, and a barrier having a first height, wherein the barrier is configured to separate the suction chamber from the discharge chamber. The pump also includes meshed first and second gears rotatably disposed in the housing. The gears are configured to draw relatively low-pressure fluid from the suction chamber, transform the relatively low-pressure fluid into relatively high-pressure fluid, and release the relatively high-pressure fluid into the discharge chamber. The barrier includes first and second portions configured to accept the first and second gears respectively, and a bridge connecting the first and second portions. The bridge is disposed proximately to where the gears mesh and is configured to provide a transition from the first height to a second height to thereby generate gradual re-expansion of the fluid away from the bridge.

Abstract: A shunt pulsation trap for a Roots supercharger reduces pulsation, NVH and improves efficiency without significantly increasing overall size of the supercharger. Generally, a Roots supercharger with the shunt pulsation trap has a pair of interconnected and synchronized parallel multi-helical-lobe rotors housed in a transfer chamber with the same number of lobes for propelling flow from a suction port to a discharge port of the transfer chamber without internal compression. The shunt pulsation trap comprises an inner casing as an integral part of the transfer chamber, and an outer casing oversized surrounding the inner casing, therein housed various pulsation dampening means or pulsation energy recovery means or pulsation containment means, at least one injection port (trap inlet) branching off from the transfer chamber into the pulsation trap chamber and a feedback region (trap outlet) communicating with the supercharger outlet pressure.

Abstract: A fluid pump having a pump housing that includes at least one expansion joint, provides volume compensation, as needed, to adjust for changes in pressure in the pump housing. Various embodiments automatically and passively reduce static pressure in the pump housing associated with a freezing event, thereby preventing damage to the pump head. Volume compensation is achieved by employing, in each expansion joint, a dynamic seal that allows relative movement of two portions of the pump housing, and a bias that provides a selected counter-force to the movement of the housing portions. The subject pumps are particularly suited for use in automotive and other rugged applications, in which fluid pumps may experience recurring freezing events.

Abstract: As a hermetic type compressor, a motor portion and a compression mechanism portion that are coupled to the motor portion with a rotating shaft interposed therebetween are accommodated in a closed vessel. The compression mechanism portion comprises a cylinder that comprises an internal diameter hole, and a main bearing and a sub-bearing in which a bearing hole that journals the rotating shaft is provided and the internal diameter hole of the cylinder is closed to form a compression chamber in the compression mechanism portion. The main bearing and the sub-bearing have a circular groove that is opened toward the compression chamber side, an inner circumferential surface of the circular groove is tapered such that a diameter increases gradually from the compression chamber side toward an opposite side of the compression chamber side, and a depth of the circular groove is set to 40% of a diameter of the bearing hole.

Abstract: A positive displacement supercharger includes a housing defining a rotor cavity with a pair of positive displacement rotors operative to carry air axially from an inlet end to an outlet in the cavity wall near an outlet end of the cavity. The outlet communicates with an outlet plenum partially defined by the cavity wall. The cavity wall includes a stiff portion defining a plurality of lightening recesses, such as a waffle pattern, limiting distortion of the wall by pulsations in the plenum. The recesses may be time and cost efficiently converted to Helmholtz tuners by covering the recesses with a cover plate, which may be perforated to include at least one tuning opening (perforation) into each tuning chamber (recess) and forming tuning volumes of the tuning chambers and their associated tuning openings effective to attenuate selected frequencies of pulsations in the plenum and thereby reduce undesired noise emanating from the air system of the supercharger.

Abstract: The scroll pump has the capability of preserving a minimal play between the joints disposed on the ridges of each of the spiraling walls and the flat wall facing it. Such an arrangement, possible owing to the slight difference in pressure prevailing between two adjacent transfer chambers, makes it possible to prevent wear and tear on the joints, soiling of the transfer chambers as well as overheating due to friction on the joints.

Abstract: A slit, spanning a distance across the top of the vane slot in a cylinder for a rolling piston compressor, safely distributes the stress which occurs in the vane slot. The slit opens onto the bore, in the cylinder, which is provided for a rotary shaft and rotary piston, and onto the vane slot.

Abstract: A pre-stressed composite liner structure is provided for tribological syss typically associated a pump, engine, compressor or systems having bearings rotating within a journal. A hollowed ceramic core is concentrically wound with cladding material in the form of a filament or braid. The ceramic core and the wound cladding form an interference fit with one another to pre-stress the ceramic core in terms of tensile strength.

Abstract: Objectionable noise in a rotary compressor is reduced by placing cavities in the sliding vane and/or the rolling piston. The cavities are used to change the local compliance of surfaces which impact one another to generate the objectionable noise. The change in the compliance of impacting surfaces is used to change the frequency of the noise generated by the impacting surfaces.

Abstract: A rotary compressor includes a cylinder with a cylindrical compression chamber. A cylindrical piston is eccentrically movable within the chamber. A vane slot extends outwardly in the cylinder from and communicates with the chamber. A vane is reciprocatingly mounted in the vane slot for selective protrusion into and retroaction from the chamber to contact the piston. At least one noise reduction slot projects into the cylinder from its outer peripheral wall near the vane slot and extends completely between the ends of the cylinder.

Abstract: A rotating piston machine has a casing 2 with a shaft 5 borne in the casing 2. In an annular space 1 there are arranged rotating elements which bear in sealing manner against the walls of the annular space 1. Each rotating element (3, 4) has four outwardly extending sector-shaped vanes (3a-3d, 4a-4d). The two rotating elements (3, 4) are arranged coaxially; their vanes (3a-3d, 4a-4d) engage in one another, so that in each case one vane of the one rotating element is arranged between two vanes of the other rotating element. By a cam track control it is achieved that, on rotation of the shaft 5, both rotating elements execute rotations with cyclic changes in the speed of rotation and the distances between the vanes (3a-3d, 4a-4d). The cam track control has in this case for each rotating element eight rolling elements which interact with an inner and an outer curved track non-positively and free from play.

Abstract: A rotary pump for pumping liquid which includes a rotor combination in the form of a vane pump or gear and rotor with pumping chambers disposed circumferentially around the rotor. The chambers progressively increase in the inlet area and ensmall in the outlet area. Resilient means are interposed between the ensmalling chambers and an outlet to block backflow of the pressurized outlet liquid into pumping chambers containing vaporized liquid instead of solid liquid, thus reducing the pump noise under conditions of vaporization termed "cavitation".

Abstract: A rotary fluid pressure device such as a motor or pump of the type utilizing a Geroler.RTM. gear set. The internal teeth of the Geroler.RTM. are tubular members mounted on bearings to be slightly movable. Between each adjacent pair of tubular teeth is a check valve in the form of a roller which is mounted to be movable slightly more than are the tubular teeth. A resilient band surrounds the rollers, biasing each of them inwardly toward engagement with the adjacent teeth, but permitting each of the roller check valves to move out of sealing engagement with the adjacent teeth when the fluid pressure in the adjacent volume chamber exceeds the combined biasing force of the resilient band and the fluid in the outer fluid chamber. The invention provides a low cost Geroler.RTM. gear set permitting greater manufacturing tolerances, and having improved low speed characteristics and volumetric efficiency, resulting from minimized tooth-tip leakage.