Abstract: A variable capacity pump includes a housing and a rotatable rotor within the housing. The rotor includes radial slots to accommodate slidable vanes or rotor blades, wherein the vanes are urged outwards by centrifugal force into contact with the inner surface of a surrounding cam ring. The cam ring is surrounded on one end by a pressure chamber including a piston under hydraulic pressure, and on the other end by a seated spring. By controlling the pressure distributed to the pressure chamber, the position of the cam ring with respect to the rotor may be changed to automatically vary the displacement of the pump in response to a pressure differential across a restriction orifice, thereby regulating the output flow to be constant over a defined speed range.

Abstract: A variable displacement vane pump comprises a pump body having inlet and outlet ports, a rotor driven by a drive shaft and co-axially aligned therewith, a plurality of radially extending vanes slidably disposed in the rotor, and a slide pivotally disposed on a pivot in the pump body and having a central axis eccentric to the axis of the rotor. A plurality of fluid chambers are defined by the rotor, vanes, and slide. A spring acts on the slide to urge the slide in one direction. A regulating chamber is configured as a semi-circular cylinder intermediate the pump body and an outer surface of the slide, wherein a pressure regulating valve pressurizes the regulating chamber to pivot the slide against the force of the spring to decrease the volume of the fluid chambers. The slide includes a slide channel formed in a face to channel fluid leakage from the fluid chambers away from the regulating chamber.

Abstract: A variable displacement vane pump comprises a pump body having inlet and outlet ports, a rotor driven by a drive shaft and co-axially aligned therewith, a plurality of radially extending vanes slidably disposed in the rotor, and a slide pivotally disposed on a pivot in the pump body and having a central axis eccentric to the axis of the rotor. A plurality of fluid chambers are defined by the rotor, vanes, and slide. A spring acts on the slide to urge the slide in one direction. A regulating chamber is configured as a semi-circular cylinder intermediate the pump body and an outer surface of the slide, wherein a pressure regulating valve pressurizes the regulating chamber to pivot the slide against the force of the spring to decrease the volume of the fluid chambers. The slide includes a slide channel formed in a face to channel fluid leakage from the fluid chambers away from the regulating chamber.

Abstract: A compact high efficiency vane pump is disclosed having a unique T-shaped vane and rotor slot configuration with a roller tip vane in a uniquely configured chamber. To minimize friction in chamber diameter, a pressure plate is provided which is hydraulically balanced, both in the forward and reverse pump and motor modes, having micro pressure pulses which vary multiple times per rotor rotation in order to compensate for varying hydraulic axial load on the housing.

Abstract: In a variable displacement pump, a relief valve is constituted by a pilot drive type relief valve obtained by adding a pilot valve to a main valve, a fluid pressure in a downstream side of a metering orifice provided in a pump discharge side passage is applied to the pilot valve, and the main valve is capable of opening and closing a downstream side passage of the metering orifice with respect to a drain passage.

Abstract: A variable displacement vane-type fluid pump is provided which permits improved regulation of the pump discharge such that the pump can meet the various requirements of lubrication for internal combustion engines at all speeds with minimized use of power. Of course, the vane pump may also be utilized in a wide range of power transmission and other fluid distribution applications. The vane pump of the invention may also use both hydrostatic and mechanical actuators to control the position of its containment ring or eccentric ring and hence, regulate the output of the pump. According to yet another aspect of the present invention, to prevent inlet flow restriction or cavitation, a valve may be provided to permit some of the pump outlet or discharge flow to bleed into the pump inlet to provide needed velocity energy to the fluid flow into the pump inlet.

Abstract: In a variable capacity type pump, in the inner diameter of a cam ring, an inner diameter of a portion forming a middle section between a suction section and a discharge section in a pump chamber is constituted by a negative slope curve in which an end portion of a suction port is set to be a start point, and a complete round curve and a negative slope curve are connected by a high-order curve.

Abstract: A variable capacity pump includes a housing and a rotatable rotor within the housing. The rotor includes radial slots to accommodate slidable vanes or rotor blades, wherein the vanes are urged outwards by centrifugal force into contact with the inner surface of a surrounding cam ring. The cam ring is surrounded on one end by a pressure chamber including a piston under hydraulic pressure, and on the other end by a seated spring. By controlling the pressure distributed to the pressure chamber, the position of the cam ring with respect to the rotor may be changed to automatically vary the displacement of the pump in response to a pressure differential across a restriction orifice, thereby regulating the output flow to be constant over a defined speed range.

Abstract: A regulatable pump, in particular a vane pump, is provided with a rotor, with a rotor body and with at least one guide ring and with a cam ring. The eccentricity of the cam ring can be adjusted by means of a regulating piston, a journal of the cam ring lying between a spring-pretensioning means and the regulating piston. At maximum eccentricity, the cam ring bears on the outside by means of a bearing part of its circumferential wall against a bearing surface on the inside of the housing.

Abstract: An adjustable fixed displacement vane pump is disclosed which includes a pump housing defining an interior pumping chamber having a central axis extending therethrough, a rotor member mounted for rotational movement within the interior pumping chamber of the pump housing about an axis aligned with the central axis of the interior pumping chamber, the rotor member having a central vane section with a plurality of circumferentially spaced apart radial vane slots formed therein, each vane slot supporting a corresponding vane element mounted for radial movement therein, and each vane element having an outer tip surface, a cam member mounted for pivotal movement within the interior pumping chamber of the pump housing about a fulcrum axis extending parallel to the central axis of the rotor member, the cam member defining a cam body having a circular bore extending therethrough for receiving the rotor member, the circular bore forming a cam chamber defining a cam surface making continuous contact with the outer tip

Abstract: A variable displacement vane-type fluid pump is provided which permits improved regulation of the pump discharge such that the pump can meet the various requirements of lubrication for internal combustion engines at all speeds with minimized use of power. Of course, the vane pump may also be utilized in a wide range of power transmission and other fluid distribution applications. The variable displacement vane pump of the invention may utilize both hydrostatic and mechanical assistance in radially positioning its vanes to ensure efficient and quiet operation of the pump and to facilitate priming of the pump. The vane pump of the invention may also use both hydrostatic and mechanical actuators to control the position of its containment ring or eccentric ring and hence, regulate the output of the pump.

Abstract: In a variable capacity type pump, in the inner diameter of a cam ring, an inner diameter of a portion forming a middle section between a suction section and a discharge section in a pump chamber is constituted by a negative slope curve in which an end portion of a suction port is set to be a start point, and a complete round curve and a negative slope curve are connected by a high-order curve.

Abstract: A variable displacement vane pump includes a pump housing having a cylindrical interior chamber, a cylindrical rotor member mounted for rotational movement within the interior chamber of the pump housing, a cam member mounted for pivotal movement within the interior chamber of the pump housing about a fulcrum aligned with the vertical centerline of the interior chamber, the cam member defining a cam body having a circular bore extending therethrough for receiving the rotor member, the cam body having lateral sealing lands formed thereon, the sealing lands having arcuate sealing surfaces defining segments of a cam arc through which the cam member pivots, and static cam seals supported within the interior chamber of the pump housing and oriented on each end of a chord of the cam arc, each cam seal biased into a continuous contact position with an adjacent sealing surface of the cam member.

Abstract: In the back pressure groove structure of a variable displacement vane pump comprising a rotor rotatably contained in a pump housing and having a plurality of vane grooves arranged radially and equidistantly in a circumferential direction, a cam ring is arranged in the pump housing in a movable and displaceable manner, fitted into the pump housing to form a pump chamber with an outer peripheral portion of the rotor and applied with an urging force to provide a maximum volume of the pump chamber. A side plate is contained in the pump housing in a non-rotatable manner, slidably contacting with one sides of the rotor and the cam ring and having back pressure grooves communicating with the vane grooves.

Abstract: A compact high efficiency vane pump is disclosed having a unique T-shaped vane and rotor slot configuration with a roller tip vane in a uniquely configured chamber. To minimize friction in chamber diameter, a pressure plate is provided which is hydraulically balanced, both in the forward and reverse pump and motor modes, having micro pressure pulses which vary multiple times per rotor rotation in order to compensate for varying hydraulic axial load on the housing.

Abstract: A regulatable pump, in particular a vane pump, is provided with a rotor, with a rotor body and with at least one guide ring and with a cam ring. The eccentricity of the cam ring can be adjusted by means of a regulating piston, a journal of the cam ring lying between a spring-pretensioning means and the regulating piston. At maximum eccentricity, the cam ring bears on the outside by means of a bearing part of its circumferential wall against a bearing surface on the inside of the housing.

Abstract: In a variable displacement pump, a relief valve is constituted by a pilot drive type relief valve obtained by adding a pilot valve to a main valve, a fluid pressure in a downstream side of a metering orifice provided in a pump discharge side passage is applied to the pilot valve, and the main valve is capable of opening and closing a downstream side passage of the metering orifice with respect to a drain passage.

Abstract: A pump for supplying fluid, in particular hydraulic oil, comprises a drive shaft extending into the interior of the pump housing and the shaft is mounted on at least one bearing device lubricated by a partial flow of the fluid supplied. A sealing device seals the radial gap between the housing of the pump and the drive shaft. The sealing device comprises a sealing ring of substantially U-shape cross-section. One arm of the U forms a first sealing portion resting against the drive shaft under pre-stress. The other arm of the U forms a second sealing portion resting under pre-stress against a sealing face of the housing surrounding the drive shaft. The sealing ring has a sealing area connecting the first and second sealing portions and forming the base of the U and facing the interior of the pump so that the first and second sealing portions extend from the sealing area in a direction away from the interior of the pump.

Abstract: In a variable displacement pump, a pump body has an inner surface and is formed with suction and discharge paths communicating with the inner surface. First and second fluid pressure chambers are divisionally formed between the inner surface of the pump body and an outer surface of a cam ring through a seal portion including a swing fulcrum pin. A spring biases the cam ring from the second fluid pressure chamber toward the first fluid pressure chamber. A metering restrictor is provided between the discharge paths. A control valve is connected to the discharge paths formed upstream and downstream, respectively, of the metering restrictor and to the first and second fluid pressure chambers, and is driven by fluid pressures present upstream and downstream of the metering restrictor.

Abstract: A variable displacement pump has a swingable, displaceable cam ring fitted to form a pump chamber together with the outer circumferential surface of a rotor having vanes. Notches are formed by notching to have a substantially V-letter shape in the starting end portions, in the rotating direction of the rotor, of a pump suction opening and pump discharge opening that open to the pump chamber. The notch formed in the starting end portion, in the rotor rotating direction, of the pump suction opening is constituted by a plurality of notched grooves aligned in the radial direction of the pump chamber and having different lengths in the rotating direction of the rotor. Hence, the timing at which the pump suction opening communicates with a pressure chamber formed between the vanes changes in accordance with swing and displacement of the cam ring.

Abstract: A cam case 23 is provided which swingably supports a cam ring 34 for forming a pump chamber 36 from a rotor in a state in which the rotor 33 having a vane 33a is moved to an eccentric position such that a swingable pin 35 axially disposed is used as a fulcrum. A pump body is formed adjacent to the two axial ends of the cam case. Moreover, a front body 21 and a rear body 22 for rotatively supporting a rotational shaft 40 of the rotor are disposed. As one of locating means for locating the two bodies and the cam case when an assembling process is performed, the swingable pin is employed. As another locating means, at least one of joining means for integrally connecting the two bodies and the cam case is a reamer bolt 45A.

Abstract: A variable capacity pump includes a rotor, a plurality of vanes, a cam ring, a spring, a variable orifice, first and second fluid pressure chambers, and first and second openings. The spring biases the cam ring to a position where a volume of the pump chamber of a portion ranging from a pump suction region to a pump discharge region becomes maximum. The variable metering orifice is formed midway along a discharge passage of a pressure fluid discharged from the pump chamber. The first and second fluid pressure chambers are formed between the outer circumferential portion of the cam ring and the inner circumferential surface of the pump body to be divided in a biasing direction of the cam ring, and swing the cam ring upon introduction of input and output fluid pressures of the metering orifice thereto. The first and second openings respectively open to the pump suction region and the pump discharge region of the pump chamber to have opening areas that are changed by a swing of the cam ring.

Abstract: A hydrostatic transmission for a transaxle which contains two flanged mounting surfaces which are used to secure the transmission to the lower housing of the gear axle. A third point is used as a pilot diameter during assembly but is not required to secure the transmission to the gear axle. Such an arrangement provides a compact and efficient hydrostatic transmission for a transaxle which can be readily assembled and also provides extended service life for the internal components of the hydrostatic transmission.

Abstract: In a controllable vane pump for pumping lubricant through a lubricant circulating system of an internal combustion engine wherein a pivotally supported control ring surrounds the vanes which rotate with the pump rotor and engage the inner walls of the control ring to form therewith pump spaces for pumping an amount of fluid which depends on the pivot position of the control ring and means are provided for biasing the control ring with a certain force toward a pivot position for greatest pump volume, the control ring defines with the housing an inlet pressure chamber which is maintained at the pressure of the lubricant at the pump inlet and a discharge pressure chamber which is maintained at the pump discharge pressure whereby the differential force generated by the pressures in said inlet and discharge pressure chambers is balanced by the force applied to the control ring by the control ring biasing means.

Abstract: A variable displacement vane pump comprising a durable rotor member having journal ends at each side of a larger diameter central vane section comprising vane slots having well areas which slidably-engage a mating vane element. The present vane pump comprises an outer cylindrical cam enclosure or spacer loaded against ring seal elements to support the faces of the seal elements closely spaced from the cam faces and reduce the actuation force required for adjustment of the displacement capacity of the pump. The cam faces include a biased segment seal in the high pressure discharge arc area. The seal elements include first fuel inlet passages in the inlet arc segment thereof, and fuel discharge passages in the discharge arc segment thereof, both of said passages being open to the vane slot extensions and to the cam chamber for the continuous supply and pressure discharge of fuel.

Abstract: A novel single acting variable displacement vane pump (VDVP) incorporating novel vanes and undervane venting which produce selective regulated pressure-loading of the vanes against the cam surface and more positive tracking in the incoming seal arc and the outgoing or discharge seal arc of the pump rather than uniform pressure balancing of the vanes throughout the 360.degree. cam chamber. The vanes incorporated into the present pumps preferably are sectional two-piece vane assemblies comprising an upper vane section which slidably supports a lower vane section and incorporates a fluid pressurizable cavity between said vane sections which, when pressurized, forces the vane sections in opposite radial directions, and which enables the vane sections to come together and integrate when the cavity is depressurized. The vane cavity is open to the fluid pressure on one side of the vanes while the undervane area of the vane slots, below the vanes, is open to the fluid pressure one the opposite side of the vanes.

Abstract: A variable displacement vane pump having a vaned rotor adjustably contained within a cam member for rotation between fuel inlet and fuel discharge arcs. Adjacent vanes form enclosed fuel bucket areas which are expanded and axially-supplied with fuel in the fuel inlet arc and are contracted and axially-discharge the fuel in the fuel discharge arc. Fuel circulation is improved by providing a central recess at each vane tip and/or a central groove in the cam surface to prevent trapping, stagnation and overheating of fuel at the centerpoints of the bucket areas, which overheating can result in expansion of the vane tips, scoring of the cam surface and pump failure.

Abstract: Multi-stage regulator for lubricant pumps with continuously adjustable displaced volumes in particular for lubricant pumps, with a regulating piston to which pressure can be applied from pressure derived from the output side of the pump, and with increasing pressure can be displaced counter to the force of a flexible restoring element.

Abstract: A rotary vane/expansion device having a housing, a rotor with a shaft having an axis, a plurality of telescoping vanes extending radially outwardly from the axis to rotationally contact the inner wall of the housing. There is a movable housing which rests on a track. There are two sets of drive pistons. One drives the piston (and housing) in one direction which is in a plane perpendicular to the axis of the shaft. The second drive piston drives the housing along the track in the opposite direction so that the amount of compression can be controlled. The outer edges of the vanes are provided with pin rollers to reduce wear. Telescoping vanes are also disclosed. The cross-section of the housing in a plane perpendicular to the axis has an ovoidal shape. This can also be used to obtain fresh water from salt water. Salt water is placed in a tank with heating coils in it. The tank has an overhead dome with a trough to catch condensed water.

Abstract: To restrain the swinging of a movable displaceable cam ring and a spool of a control valve and to suppress pulsation on the discharge side of a variable displacement pump. In the variable displacement pump, a variable metering orifice (40) is provided midway in discharge-side passages (24, 29, 43, 44, 45) extending from a pump chamber. A spool-type control valve (30) is operated with the fluid pressure on the upstream and downstream sides of the orifice to control the fluid pressure supplied to fluid-pressure chambers around the cam ring in accordance with the flow rate of the fluid discharged from the pump chamber. A single or multistage throttle portion including throttles (50, 51, 52) is provided in at least one of fluid passages (46, 47) for communicating the upstream side of the orifice to one chamber of the valve, and fluid passages (35, 19b) for communicating the one chamber to the first fluid-pressure chamber as the valve operates.

Abstract: A pump comprising a durable rotor member having large diameter journal ends at each side of a central vane section comprising vane slots having well areas which slidably-engage a mating vane element. The present vane pumps comprise novel cylindrical floating ring seal elements having a support body which continuously seals the face of the cam member, and have a movable inner ring assembly which becomes pressure-loaded against the rotor journals during use, to minimize or limit axial pressure leakage while balancing or minimizing bearing load.

Abstract: A cam ring for forming a pump chamber on the outer periphery of a rotor which is rotatable in a body is arranged movably, and is urged in a direction in which the volume of the pump chamber is made maximum. Sealing means are interposed in an annular gap space on the outer periphery of the cam ring between the cam ring and the body, thereby forming first and second fluid-pressure chambers for allowing the cam ring to undergo displacement by moving. A spool-type changeover valve is provided which is operated in accordance with the discharge flow rate of the pressure fluid from the pump chamber to control the fluid pressure supplied to the first and second fluid-pressure chambers. The fluid pressure on the downstream side of a metering orifice 29 provided in a pump discharge-side passage 28 is introduced into the second fluid-pressure chamber for imparting moving displacement in the direction in which the volume of the pump chamber is made maximum, through a passage 37 via a second valve chamber 32b.

Abstract: When one chamber of vane pump is located at an end of a discharge process and is compressed at maximum, pressure in the chamber is higher than the discharge pressure of the pump. Vanes are supported in slits of a rotor. A passage connecting the one chamber and inner sides of the vanes in the slits supplies pressure to push the vanes onto an inner surface of a cam-ring of the pump.

Abstract: A vane pump has a casing, a controlling collar guided leaktightly in the casing and movable relative to a rotor mounted in the casing and surrounded by the controlling collar. The movement of the collar is transverse to the axial direction of the rotor. A suction region of the pump is defined by a volume increasing in the direction of rotation of the rotor, of a vane cell formed between two adjacent vanes and decreasing to the pressure region. At least one adjustment member is provided to adjust the position of the controlling collar in dependence on the prevailing pumping parameters. In order to provide a vane pump of space-saving and/or simple and cost-saving design, at least one recess is open towards the outside of the controlling collar and is provided on the controlling collar close to the pressure region to accommodate and adjustment member.

Abstract: A fluid pressure driving system for a vehicle includes a reservoir tank in which an amount of fluid is stored, a variable capacity oil pump sucking the fluid from the reservoir tank and discharging the resultant fluid, a control device for adjusting a quantity of the fluid discharged from the variable oil pump, and a distributor valve having an inlet port for receiving the fluid from the variable capacity oil pump. The distributor valve discharges a fixed amount of the fluid and the remaining amount of the fluid from a first outlet port thereof and a second outlet port thereof, respectively. A first passage connects the first outlet port of the distributor valve and the reservoir tank. A second passage connects the second outlet port of the distributor valve and the reservoir tank. A power steering device is associated with a steering wheel and disposed in the first passage. A hydraulic motor is disposed in the second passage, and a cooling fan is mounted rotatably on the hydraulic motor.

Abstract: A noise and cavitation suppressing variable fluid volume vane type rotary pump has fluid inlet and outlet ports in communication with the interior portion of a pump housing. A cam ring is arranged in an inner chamber of the pump housing, for enabling adjustment of fluid flow volume in the pump, and the cam ring is pivotable for allowing eccentric displacement thereof. A rotor having a plurality of vanes arranged in the radial direction thereof so as to make touching contact with an inner circumferential surface of the cam ring is rotatably arranged in the space defined within the inner circumference of the cam ring. First and second containments are defined at uppermost and lowermost points between the cam ring and the rotor. The cross sectional areas of the containments vary according to eccentric displacement of the cam ring.

Abstract: A lubricating groove not communicating with other oil passages and extending in the circumferential direction is provided on the side surface of a cam ring. The central portion in the circumferential direction of the lubricating groove is located at the center of the suction side, and both ends of the lubricating groove reach the positions beyond a straight line joinning the upper and lower dead points. As a result, the side surface of the cam ring of the variable-displacement vane pump is prevented from seizing.

Abstract: A variable volume type vane pump comprises a housing, a rotor having a plurality of vanes, a cam ring disposed to be adjacent to said rotor, and a cover. A control piston is arranged for slidably displacing the cam ring relative to the housing and the cover. The housing, the cam ring, the control piston, and the cover cooperating to define an oil reservoir. A pressure within the oil reservoir is adjusted by a check valve.

Abstract: A variable capacity type vane pump comprising a cam ring, a rotor placed for rotation within the cam ring. The rotor has a number of radial slots, and vances placed for radial inward and outward movement in the receptive slots each having a bottom. A pump chamber is defined between the cam ring and the rotor and it has an inlet and outlet port. The outlet port is connected through a conduit to the bottom of at least one of the slots having vanes moving inwardly in the respective slots. A restriction orifice is placed in the conduit. The cam ring is moved with respect to the rotor to vary the capacity of the vane pump in response to a pressure differential across the restriction orifice.

Abstract: A vacuum vane pump wherein one or more stages are installed in an annular extension of the casing for the pump motor. Each stage has a rotor which is driven by the motor shaft by way of an elastic key, and an annular housing which surrounds and is eccentric relative to the rotor. The housing is pivotable about a pintle which is installed in the end walls of the casing and is parallel to the motor shaft. The width of an annular clearance between the external surface of the housing and the internal surface of the extension can be varied by a radially disposed screw which is mounted in the extension diametrically opposite a spring-loaded abutment for the housing. The components of each stage are biased to predetermined axial positions by springs which react against the extension and bias one end wall of the casing against the adjacent housing and rotor, either directly or by way of a partition.

Abstract: A variable-displacement vane-pump has a rotor which is rotatably supported by a pump housing in coaxial relationship therewith, and a cam ring interposed between the rotor and the pump housing in eccentric relationship with the pump housing. The rotor has radially outwardly slidable vanes on its outer peripheral surface in contact with an inner surface of the cam ring. Two side plates are disposed on both sides of the vanes, thereby defining pump chambers between every adjacent vanes. An arc-shaped intake port and an arc-shaped exhaust port are formed in one of two side plates, and respectively open into the pump chambers along one side face of the cam ring. In the other side face of the cam ring, a groove is formed except for the region corresponding to the exhaust port, and a partially cut off annular friction ring is disposed within the groove while urged by a seal ring into close contact with the other side plate.

Abstract: The invention relates to a radial piston machine comprising height adjustment means, control means and adjustment means all having abutment means designed such that the cam ring of the machine will carry out during its adjustment a substantially rolling movement.

Abstract: A multiple or compound work cycle, eccentric rotor, fluid power translation device, featuring adjustable and reversible work output capability, essentially comprising: A symmetric rotor having a plurality of fixed radially extended vanes rotating closely between opposing co-axially adjustable confinement plates. An internal, eccentrically disposed annulus comprised of segmented concentric rings having co-axially protruding edges; said edges engaging circular, matching bearing grooves provided by said opposed confinement plates. The segments comprising each segmented ring being each penetrated by a rotor vane; two or more segments per vane thereby compelling co-rotation of said segments and locating said segments relative segments penetrated by adjacent rotor vanes.

Abstract: In general terms the invention provides for a direct actuated pressure regulated vane-type pump having a adjustment piston which is under the influence of the pump pressure. The adjustment piston is coupled to said cam ring by means of a flexible or articulate connection means, or else the adjustment piston itself is of a flexible or articulate design.

Abstract: In a volumetric blade pump for fluid-hydraulic actuation, provided with a blade-bearing rotor and with a stator of annular shape mounted around the rotor, for the closure of the stator, on at least one side of the stator, a couple of plates are provided, of which one, stationary, rigidly constrained at the outside of the stator side, and the other, movable, positioned inside the stator between the stationary plate and the rotor; on both faces of the movable plate the delivery pressure of the pump is active.

Abstract: An adjustable rotary vane pump for changing the direction and rate of fluid flow through the pump. The pump comprises a first pump housing having a generally cylindrical chamber therein along a central axis of the housing. A second housing is provided having a second chamber therein coaxially oriented with the first housing. An insert member is provided in the second housing having an aperture therein of a given eccentricity. The insert member is slidably adjustable for rotational movement within the second housing for providing varying cross-sectional dimensions for the fluid flow through the pump. A rotor is disposed in the housing coaxial with the first and second housing. A plurality of vane members are provided on the rotor which respectively engage the walls of the first chamber and the insert member within the pump.

Abstract: A hydraulically driven bicycle frame with two axle members coupled to the bicycle frame and front and rear wheels mounted on such axles for rotation about the axis of the respective axle and a pair of pedals mounted on a pedal drive shaft coupled to the bicycle frame for rotation for applying manual power for operating the hydraulic system of the bicycle. The hydraulically driven bicycle has a hydraulic pump mechanism and a hydraulic drive mechanism. The hydraulic pump mechanism is operated by rotational movement of the pedal drive shaft. The hydraulic pump mechanism includes a pump housing having two sectional pump housing members that form a pump chamber between them. The two sectional pump housing members are capable of relative movement with respect to each other so that the pump chamber is capable of being varied in size for varying the flow of fluid through the pump mechanism.

Abstract: A variable-capacity roller- or vane-type pump has a cam ring which is movable to vary the delivery of the pump and means is provided for applying to the movement of the cam ring a damping force which varies in dependence upon the instantaneous position of the cam ring.

Abstract: A roller or vane type pump is described of the kind in which the cam ring is pivotally mounted within an external casing to vary the throw of the cam ring and hence the pump delivery means is provided whereby a constant flow is obtained regardless of the pump speed. The cam surface of the cam ring is not wholly circular. The two portions of the cam surface extending between the inlet and outlet ports of the pump at opposite sides respectively of the pump axis have curvatures such that the instantaneous distance R.sub.2 of the point of contact of one of the sealing rollers or vanes with the cam surface from the axis of rotation of the rotor is given by R.sub.2 =.sqroot.R.sub.1.sup.2 +k where k is a constant and R.sub.1 is a corresponding instantaneous distance of the point of contact of the other sealing roller or vane with the cam surface from said axis.

Abstract: A reversible flow vane pump having a pump case with a pump chamber in which a rotor is mounted. The rotor has outwardly-opening slots which carry vanes which engage a cam ring and with fluid chambers between vanes. The cam ring can be adjusted to positions at either side of a neutral position to provide reversible flow operation between a pair of ports, with variable volume control. The ports are arranged to increase the length of time in which a port communicates with an intervane fluid chamber which is of decreasing volume for increased utilization of fluid being pressurized. A port which functions as an inlet port in a predominant mode of operation of the pump has an extension effective to increase the length of time in which an intervane fluid chamber of increasing volume can be filled with fluid.