Abstract: A hydrostatic radial piston machine 10 is proposed, whose adjustable reciprocating ring 18 has integrated means for detecting the eccentricity 20 between the reciprocating ring 18 and the rotor 14. In combination with the rotating rotor 14 and the binding of the sliding blocks 17 to this reciprocating ring 18, the eccentric location of the reciprocating ring 18 leads to a reciprocating motion of the work pistons 16 in a radial direction. Together with the kinematic conditions in the radial piston machine 10, this leads to a change in the spacing between two successive sliding blocks 17. This change in spacing varies in proportion to the eccentricity 20 of the reciprocating ring 18 and is therefore detected by a measuring instrument. To that end, this measuring instrument has a measured value pickup 27, which is integrated in the reciprocating ring 18 and outputs an increased voltage signal as long as sliding blocks 17, which act as measured value transducers, move past it.

Abstract: In an inner cam type injection pump, the side surface of the protruding portion of each of the plungers facing the compression space is formed in a projecting shape in the area where the plunger changes from the base end side into the front end. Specific forms of the projection include a structure constituted with slanted surfaces over a plurality of stages with different inclinations relative to the axis of the plunger, an arc form and a structure provided with a overhanging portion formed on the side surface of the protruding portion, which does not overhang the base end, projecting out from the side surface. This will prevent collision at the shoulder portion of the plunger and, consequently, prevent the deformation at the shoulder portion and ensures that plungers will not have sliding failures or become seized. Even when plungers collide, the sliding of the plungers will not be affected, ensuring that plungers do not have sliding failures or become seized.

Abstract: A radial piston pump having a shaft which is mounted in a pump housing an eccentric in the shaft and a stationary piston ring surrounding the eccentric. The piston ring receives the pistons arranged in radial direction to the shaft and surrounding the eccentric. The piston ring is provided with bore holes that open toward the eccentric, for receiving the pistons. The bore holes are closed off at their ends facing away from the eccentric by respective closure plugs. The piston ring is surrounded by a portion of the pump housing, e.g., an annular wall part, so that a liquid filled chamber is defined at least between the closure plugs and the inner side of the portion of the pump housing.

Abstract: A motor or pump includes a stator and a rotor supported for rotation with respect to the stator by a bearing arrangement. The rotor has a cylinder block thereon having radial cylinder bores equipped with radially reciprocable pistons. Rollers on the pistons abut a cam ring fixed to the stator so that the pistons to reciprocate radially to displace fluid when the rotor turns relative to the stator. The stator includes a control device fixed thereon having a pair of fluid passages therein. One side of the control device constitutes a distribution face with outlets therein connecting the fluid passages to the cylinder bores as the rotor rotates. A counterpart fastens to the rotor adjacent the opposite side of the control device so as to define an annular chamber therebetween. A shuttle valve operatively interposed between the passages and chamber ensures that the chamber remains in connection with the passage having the higher pressure.

Abstract: A radial piston hydrostatic machine having an outer housing structure comprising at least two housing elements connectable together along a parting-plane arranged perpendicular to the rotational axis of said drive-shaft to define an internal chamber, a drive-shaft supported in the housing to drive the cylinder-barrel, the cylinder-barrel having a number of radial cylinders, each cylinder containing a piston such that the pistons can bear on the track-ring, fixed abutment means in the housing and disposed radially adjacent the track-ring for resisting the action of the pistons on the track-ring and suppressing vibration emanating from the track-ring.

Abstract: A radial piston pump with pistons which pump into a circumferential pressure passage has the passage sealed on its outer side by a plastic annular member of a trapezoid-shaped cross-section. The longer parallel side of the cross-section faces radially inwardly and includes a circumferential groove for receiving a resilient O-ring which biases closed pressure valves located between the pistons and the passage. The annular member is adapted to be inserted radially inwardly into the circumferential pressure passage by expanding it and allowing it to contract into the passage. A radially inner side of the circumferential passage is, at a location between two adjacent cylinders, connected to a passage that extends radially inwardly and that is connected to an axial passage that leads to a pressure connection.

Abstract: A gear for motor vehicles provided with a positive-displacement pump for supplying a lubricating device and the control and activating devices of the gear. The positive-displacement pump is driven by the rotation of a drive motor and is provided with a suction throttle which adjusts the flow of lubricating oil such that a relatively constant flow is maintained over a varying range of rotational speeds of the drive motor. The invention provides the advantages that gear efficiency can be improved since high rotational speeds of the drive motor do not cause a excessive flow of lubricating oil.

Abstract: A radial piston pump (1), preferably for pressure medium supply of an anti-lock system of vehicle brakes, with a rotating pump shaft (3), an end section of which has a pivot (5) extending eccentrically to a longitudinal center axis of the pump shaft (3), there being arranged on the pivot (5) a rolling bearing on whose outer ring (9) are supported by their plane end faces (13) pump plungers (12) in star arrangement in a pump housing (2) and extending radially to the pump shaft (3), characterized in that the rolling bearing is designed as a needle bearing (6) with the needle elements rolling directly against the shaft pivot (5), the outer ring (9) being produced as a deep-drawn sheet metal ring with chiplessly formed edges (10,11) on both sides, in which needle-shaped rolling elements (7) are guided via a cage (8) and in which the outer ring (9) is made with a core hardness of at least 300 HV1.

Abstract: An adjustable rotor and/or a radial piston machine which may utilize an adjustable rotor. The rotor has a primary eccentric rotatable around an axis and a secondary eccentric adjustable in position relative to the primary eccentric. The radial piston machine includes a plurality of piston cartridges arranged radially around the axis and both high pressure and low pressure fluid distribution systems. Multiple units may be axially coupled. A single unit may handle a variety of fluids in various combinations.

Abstract: The invention relates to a hydraulic mechanism comprising: a cam; a cylinder block; cylinders formed in the cylinder block; pistons slidably mounted in the cylinders; thrust rollers for the pistons acting on the cam and axially defined by two transverse faces; two wedging parts for each roller, each wedging part being disposed in a recess between the end face of the roller and the inside face of the cylinder, thereby holding the roller in position, one of the wedging parts extending to the bottom portion of the recess and including a groove parallel to the axis of the piston, and a projection that is fixed relative to the cylinder being received in the groove.

Abstract: A radial piston pump for low-viscosity fuel according to a first aspect of the invention comprises a pump housing, which is constituted of as few as two structural bodies (from among a drive-side housing member 2A, a fixed cylinder 81 and a cover 4), and a leaf valve member 82 which is formed with intake valves 87 for opening and closing intake side passages 27 and discharge valves 88 for opening and closing discharge side passages 28 and is sandwiched between two structural bodies (fixed cylinder 81 and cover 4). The first aspect of the invention reduces the number of components constituting the pump housing, enables highly precise overall axial alignment, prevents wobbling of a pump shaft 9 of the pump, increases performance and reliability and reduces cost.

Abstract: A piston pump which is contemplated for furnishing fuel at high pressure, especially gasoline with low self-lubricating properties. To avoid drive-side wear, a rotatably drive eccentric element is provided as the actuating device for the pump piston of the piston pump, the driving motion of the eccentric element being transmitted to the pump piston via a flexible transmission element.

Abstract: A housing for a hydraulic piston machine comprising two shells of part-cylindrical form, the shells connectable together along a parting plane in which the rotating axis of the drive-shaft lies to contain within internal working elements of the machine. Either or both housing shells may be provided with a opening connecting the interior to the exterior of the shell(s) to provide means for fluid distribution of the machine. A non-deformable liner-element located within one or more of said openings for isolating pressurized fluid passing through the machine from coming into direct contact with the housing shells.

Abstract: A variable rate pump including a distributor member rotatable within a sleeve. The distributor member is provided with a bore within which a pumping plunger is reciprocable under the influence of a first cam lobe and a second cam lobe. A valve is provided for selecting whether fuel is supplied due to the motion of the plunger under the influence of the first cam lobe or the second cam lobe. An arrangement is also provided in which the distributor member carries first and second plungers each reciprocable under the influence of respective cam lobes. A valve is provided for selecting whether the fuel is supplied by the first plunger or by the second plunger.

Abstract: A hydraulic power unit combining a number of cylinders using ball bearings to displace hydraulic fluid sequentially with controlled flow to a number of hydraulic actuators. A power unit could combine a minimum of two cylinders through ten or twelve cylinders in a practical hydraulic power unit. The inherent bi-directional nature of this combination of fluid displacing ball bearings, cylinder and porting arrangement offers a unique opportunity to change fluid flow by reversing input drive. The torsional reaction component of the opposed reciprocator drives is utilized to rotate the core cylinder assembly to realign outlet and return fluid flow. This realignment can be used to reverse the fluid circuits or redirect the fluid to other work.

Abstract: A reciprocating piston pump having a housing, pistons disposed opposite one another in the housing, an eccentric between the pistons, annular grooves that fit around the piston necks machined into piston ends oriented toward the eccentric, and a U-shaped hoop spring curved radially outside the eccentric in the circumferential direction thereof. The hoop spring includes forklike hoop spring ends which engage the annular grooves and press the piston ends toward the eccentric. In the circumferential direction of the substantially U-shaped hoop spring, a continuation is formed on the hoop spring and together with a stop disk aligned transversely to the eccentric shaft, forms a device that limits the pivotability of the hoop spring about the piston necks. The reciprocating piston pump is usable for instance in hydraulic motor vehicle brake systems and in other hydraulic equipment.

Abstract: A unit comprising a drive motor and a radial piston pump is proposed, in which unit an armature of the drive motor and an eccentric of the radial piston pup are carried by a common unitary shaft which has three bearings. A three-bearing mounting, known from the prior art, for a shaft of this kind consists of three ball bearings, which are expensive. The invention proposes to replace the ball bearing situated at the greatest distance from the eccentric in the prior art by a slide bearing, and to design the latter as a sintered metal bearing and to impregnate it with a viscous lubricant. The unit according to the invention can be used as a component of an anti-lock device of a vehicle brake installation or of a drive-slip control device acting on driven wheels.

Abstract: A pump includes a housing defining a cavity, an axial bore coaxially communicating with the cavity, at least one radial bore radially extending between the cavity and an outlet, and an inlet communicating with the radial bore intermediate to the cavity and the outlet. A crankshaft having a longitudinal axis is disposed in the axial bore for rotation about the axis and includes an eccentric portion disposed in the cavity. A piston having a base is disposed in the cavity, and has a head disposed in the radial bore for slidable reciprocation between a discharge position proximate the outlet and an intake position at the inlet between the cavity and the outlet. A cage structure including a cage and a slider block connects the piston base to the eccentric portion of the crankshaft for transforming rotation of the eccentric portion in the cavity to reciprocation of the piston in the radial bore.

Abstract: The invention relates to a hydraulic motor having a plurality of cubic capacities, and provided with individual cubic-capacity selectors associated with at least some of its cylinders, each selector being provided with a control member. According to the invention, the control member coupled to each of said individual selectors can be activated only in that range of positions of the cylinder associated with said individual selector which corresponds to the axis of said cylinder being in alignment with the crest of one of the undulations, and to positions that are angularly adjacent to the position in which said alignment is obtained. An application of the invention is to making a motor that is mechanically strong.

Abstract: An adjustable rotor and/or a radial piston machine which may utilize an adjustable rotor. The rotor has a primary eccentric rotatable with a shaft and a secondary eccentric adjustable in position relative to the primary eccentric. The radial piston machine includes a plurality of piston cartridges arranged radially around the shaft and both high pressure and low pressure fluid distribution systems. Multiple units may be axially coupled. A single unit may handle a variety of fluids in various combinations.

Abstract: Pump assembly, comprising a radial plunger pump for hydraulic fluid, having a pump housing with radial cylinders formed therein, in each of which cylinders a plunger is reciprocable by means of an eccentric rotor, an electric motor with a rotary output shaft which is connected for driving purposes to the rotor of the radial plunger pump, and a reservoir body for forming a reservoir for hydraulic fluid, the radial plunger pump, the electric motor and the reservoir body being interconnected to form a unit. The reservoir body and the electric motor are fitted at the same side of the pump housing, the reservoir body being adjacent to the pump housing at one side and at the opposite side having a recess. The electric motor preferably projects over a part of its length into the recess of the reservoir body. The reservoir body is preferably designed for fixing the pump assembly to a support.

Abstract: A rotary distributor fuel injection pump with a drive shaft coupled to a pump rotor by a radially offset and axially extending drive pin with a cylindrical head received within a radial slot in the rotor; a coaxial throughbore in the rotor providing a valve bore; a valve member in the valve bore axially shiftable to an open position by a compression spring; an electromagnet with an armature plate fixed to one end of the valve member and a stator operable, when energized, to axially shift the valve member to its closed position; a stop plate on the outer end of the rotor having an outer end face engageable by the armature plate, the end face having a plurality of lands and grooves to hydraulically dampen the axial movement of the valve member to its open position when the stator is deenergized; the armature plate having a hub received within an opening in the stop plate to couple the armature plate and valve member to the rotor; an annular thrust washer and needle bearing between the rotor and a distributor he

Abstract: A high pressure pump for an engine fuel injection system, wherein the pump has a plurality of positive displacement pumping devices that are operating so that their delivery cycles overlap and so that the instantaneous speed of the pumping devices during their delivery strokes is constant so as to minimize pressure variations in the system and avoid the necessity of having the pump being driven in synchronized relationship to the engine output shaft. This permits the use of a variable speed drive so that the pump can be driven at speed ratios depending upon engine demand and/or eliminates the necessity for positive drives to maintain synchronization. A number of embodiments showing different pump configurations are disclosed.

Abstract: A radial piston pump of the type, in which an excentric rotor (7) is adapted to cause the pistons (4) to perform a reciprocating movement within radial cylinders (3) in the pump body (1), the radial inner ends of the pistons (4) being each provided with a broadened foot (6), said broadened feet (65) being kept in contact with the rotor (7) also during the suction strokes of the respective pistons (4) by means of a coupling ring (26) of a substantially L-shaped cross section, the axial ring portion (26a) of which engages the radial outer end faces of the broadened feet (6) and the radial portion (26b) of which keeps said ring (26) axially in place.

Abstract: A damped piston assembly is configured for use in a vehicle anti-lock braking system pump includes a piston, an insert and an elastomeric annular element. The piston has an axial cavity in a piston end portion. The insert has a cylindrical portion slip fit to the axial cavity of the piston. The insert also has a lip at an insert end portion with a diameter larger than the axial cavity of the piston and less than or equal to an outside diameter of the piston. The an elastomeric annular element is positioned between the lip of the insert and the end portion of the piston. The elastomeric annular element defines a gap between an end of the cylindrical portion of the insert and a bottom of the axial cavity in the piston when the piston is in an unloaded condition.

Abstract: A hydrostatic piston machine having a housing comprising two shells of a part-cylindrical form, the shells connectable together along a parting-plane in which the central axes of the drive-shaft and cylinder-barrel lie. Each housing element is provided with a number of semi-circular formations and recesses which form pockets or apertures when the housing shells are connected together to provide support surfaces for the working elements of the machine. A cylinder-barrel mounted within a chamber formed between the shells and is provided with a number of cylinders each containing a piston. Fluid-passageways are provided in the housing to receive and supply fluid to the pistons of the machine.

Abstract: A radial piston hydrostatic machine contained within a housing and comprising a cylinder-barrel mounted to rotate on a pintle-valve fixed to said housing. Two hydraulic-rams operatively acting on a track-ring to provide eccentric displacement relative to the pintle-valve to change the rate of fluid output from the machine. The hydraulic-rams being of unequal size and subjected to the same level of machine discharge pressure during periods when the level of discharge pressure is insufficient to cause an internally disposed pressure relief-valve to "open". A throttle-valve disposed in a fluid channel linking the cylinders of said hydraulic-rams and arranged to introduce a pressure differential across two said two cylinders during periods when the machine discharge pressure is sufficiently high to cause said pressure-relief-valve to "open".

Abstract: A two stage pump has coaxial first and second stage reciprocating pumps with the second stage piston reciprocably driven by the first stage piston. Multiple sets of first and second stage pumps are provided, and the second stage pistons can be returned by supercharge pressure, a loose connection between the first and second stage pistons, or a spring. An accumulator which is charged on a compression stroke and discharged on an intake stroke may also be provided in communication with a pumping chamber to improve the efficiency of a pump.

Abstract: The hydrostatic motor of this invention includes a fluid pressure unit having a stator and a rotor. The rotor includes a cylinder block containing a plurality of radially disposed cylinder bores therein. At one end, close to the axis of the rotor's rotation, each of those cylinders is connected to a corresponding bore extending substantially in axial direction. Therefore, the center lines of the outlets of all bores are disposed on the same pitch diameter on the front face of the cylinder block. On this front face a distribution face of the cylinder block is provided containing said outlets. A lobed cam ring is fixed to the stator. Each cylinder bore houses a roller abutting the cam ring and thereby reciprocating a piston radially within the bore in response to the lobes of the cam ring. A control device is provided as a part of the stator.

Abstract: A slipper guide for use in radial piston type hydraulic pumps and motors, especially those utilized in hydrostatic transmissions. The slipper guide provides an annular path for the slippers, guiding and maintaining the slippers engaged with the inner circumferential surface of the track ring as the slippers are rotated within the track ring by the cylinder. The slipper guide consists of two plates axially attached to the track ring and fixed relative thereto. Each plate includes an annular, axially inwardly extending projection forming an annular surface upon which an under surface of an outer portion of the slippers rests. The annular projection positions and maintains the top surface of the slippers against the inner circumferential surface of the track ring.

Abstract: A motor or pump assembly (1) comprises a cylinder block (4) with a plurality of radially positioned cylinders (3), a piston (2) arranged slidably reciprocable in each of the cylinders, a cam ring (7) cooperating with the pistons and being rotatably journalled on the cylinder block, and a distributor valve (9) arranged centrally in the cylinder block to control a flow of fluid to and from the cylinders in operation. The cam ring (7) is journalled on the cylinder block (4) with at least one ball bearing with balls (25) arranged on each side of the cylinder block. These balls run in grooves which are positioned close to the sides and periphery of the disc-shaped cylinder block. This provides a structure which has a very small axial length and which is simultaneously capable of absorbing great loads both radially and laterally.

Abstract: A hydraulic drive system for bicycles and the like comprises a casing adapted for enclosing a hanger portion of the bicycle, planetary gear type speed up gears including a carrier integral with a crankshaft for increasing the number of rotations of the crankshaft, an eccentric cam assembly including an outer eccentric cam and an inner eccentric driven by a sun gear of the speed up gears and a variable displacement hydraulic pump having plungers driven by the cam assembly and provided at an input portion of the driving system, the speed up gears, the eccentric cam assembly and the variable displacement hydraulic pump being housed in the casing.

Abstract: A vibration and noise free pump is disclosed. The pump includes a plurality of cylinders in radial arrangement about an axis. A piston is slidably supported in each of the cylinders. Each of the pistons has a vent opening in addition to a set of inlet openings to admit escape of liquid out of its piston inner chamber into a well with the piston in the compression stroke. With the provision of the vent opening, a surge pressure in each of the pistons has been reducedsed.

Abstract: A pump comprising a number of radial cylinders arranged a given angular distance apart about a drive shaft and each housing including a piston resting radially on a respective pad by virtue of the action of a return spring. The connection between the piston and pad comprises a retainer for preventing in-service detachment of the pad, which rests on a respective flat portion of a cam mounted for rotation on an eccentric portion of the shaft. The force on the pad produced by sliding friction between the pad and the flat portion of the cam and directed perpendicular to the axis of the cylinder is absorbed by the piston.

Abstract: Radial pump with a rotary shaft (4) on which an eccentric (6) is fitted. A sleeve (8) to which a plurality of pistons (12) is connected is fitted rotatably on the eccentric (6). The connection between the sleeve (8) and the pistons (12) is achieved by a part made of elastically deformable material (9) which is fitted around the sleeve (8). A controlled opening and closing movement of the pistons is thus obtained through rotation of the pump shaft (4). More than one series of pistons can be fitted around the shaft.

Abstract: A pump with axial thrust compensation having an external housing, a main shaft within the housing to which are axially fixed two spaced apart rotors. The main shaft supports the rotors apart at respective collars against which the rotors are clamped. Each rotor including a series of radially displaceable elements within respective bores. The stroke rings for the rotors are rigidly attached to each other by a respective bearing shaft. A respective stroke ring around each rotor for moving the displaceable elements into and out of the bores. A respective control slot into each of the bores in the rotor and the control slots of each rotor extending laterally toward the other rotor.

Abstract: A variable-stroke crank mechanism has a crankshaft rotatably supported in a casing for relative rotation about an axis with a crankpin displaced out of alignment with the axis. An eccentric collar is rotatably mounted on the crankpin for revolving around the axis in response to the relative rotation of the crankshaft with respect to the casing to reciprocally move an actuator relative to the casing. A stroke adjusting mechanism for adjusting angular displacement of the eccentric collar on the crankpin comprises an internal ring gear integral with the eccentric collar concentrically with the crankpin, a planetary pinion rotatably mounted on the crankshaft and meshing with the internal ring gear, a sun gear meshing with the planetary pinion, and a stroke adjusting shaft rotatably disposed axially in a portion of the crankshaft and coupled to the sun gear, whereby the stroke adjusting shaft is adjustable in angular displacement to adjust a stroke of reciprocating movement of the actuator.

Abstract: The invention proposes a fluid handling device, which may be a pump, in which arrangements are provided to make the device able to handle high pressure of more than one thousand atmospheres and able to seal at such high pressure for a considerably long life time of the device. For the obtainment of such a performance, a piston shoe arrangement has a part-ball formed portion with an outer face which is guided on a cylindrical inner face, while the piston shoe at the same time pivots around a center which is located in the pistons-head. Sealing means are provided to faces of plates, membranes or pistons to reduce leakage or to reduce the negative effects of deformations under high pressures. In this relation a thrust body may be axially moveably provided in a thrust chamber and obtain thereby a novel and effective sealing of membranes and faces.

Abstract: A radial cylinder hydraulic pump or motor has radial pistons each provided with a guide pad urged against the cylindrical inner surface of a guide element. A continuous series of rollers cover the cylindrical inner surface and are interposed between such surface and the guide pads. The rollers are prevented from coming in contact with each other by a number of auxiliary smaller rollers. Between each piston and its respective guide pad there is interposed a sliding member which is slidably mounted on the pad along a tangential direction.

Abstract: A pump having a number of radial cylinders each housing a sliding piston. Each cylinder is closed by a respective head, and comprises an intake valve and a delivery valve having respective seats inside a plate. The intake valve is located at the end of an intake channel having a first portion through the plate, a second portion formed between the head and the plate and perpendicular to the axis of the cylinder, and a third portion parallel to the cylinder axis. The delivery valve presents a truncated-cone-shaped seal communicating with the pumping chamber via a conduit also extending through the plate; and the two plungers are made of ceramic and guided by a respective retainer.

Abstract: A pumping apparatus is disclosed comprising a tank containing a fluid to be umped, a main pumping stage for pumping a controlled amount of said fluid at a predetermined pressure, a supply pump for supplying fluid from said tank to said main pumping stage in excess to said controlled amount, and feedback means for feeding the excess fluid back to said tank along a given drain path; wherein the improvement includes at least part of said drain path running in regions of said main pumping stage subjected to severe thermal and/or mechanical stress.

Abstract: A radial piston pump includes a plurality of radially arranged cylinder-pger assemblies having suction valves and pressure-regulating valves, with the plungers being controlled by an eccentric disk which eccentrically circulates relative to a housing accommodating the cylinders. In order to provide a radial piston pump of this type with a simple design and to allow a digital operation of the pump for controlling the flow rate, the space between the end faces (12) of the cylinders (9) and the pertaining plungers (7) is connectable with a pressure manifold (19) of the pump by a randomly controllable valve (21, 22), with the plungers (9) of the pump preferably having different diameters.

Abstract: The ease of assembly of a radial plunger pump is improved while preventing an external leakage of liquid. A pump housing 2 in the form of a cylinder having a closed bottom contains a pintle 4 therein, which is secured to the bottom of the pump housing 2 by a bolt 6. A rotor 8 is rotatably fitted around the pintle. The rotor is formed with a plurality of radially extending cylinder bores 8a, in each of which a plunger 10 is slidably disposed. A guide ring 16 is disposed around the rotor. A motor 20 is fastened to and secured to the opening of the pump housing, and includes a drive shaft which is connected to the rotor to drive it for rotation. By allowing parts to be assembled into the pump housing in one direction, the ease of assembly is improved while preventing a liquid leakage.

Abstract: A suction-restricted radial piston pump is described, in particular for use with automotive vehicles. The pump delivers a flow constant over a broad speed range and involving low losses in output and generating only negligible noise. In one embodiment, a control slot (13), on the pressure side, is subdivided into several grooves (27,28) which at least in part are in communication, through check valves (32), with the pressure connection (20). An alternative embodiment provides a shape of the pressure-sided control slot in which the introducing end thereof is comparatively narrow to reduce noise at a high speed and the outlet-sided end thereof with a wider width sufficient to meet the required output. According to a third embodiment, the suction-sided slot (12) is provided with a narrow width section and a subsequent wider width section.

Abstract: A piston pump is constructed so that the displacer or piston working strokes occur in sequence with varying phase differences which have a non-integral ratio to one another. Thereby, the risk of excitation of noise or resonance vibrations is greatly reduced.

Abstract: A variable-stroke radial-plunger-type apparatus for use as an air compressor, for example, has a main shaft rotatably disposed in a casing assembly, an eccentric collar angularly movably mounted on a eccentric crankpin of the main shaft, and a coupling ring angularly movably mounted on the eccentric collar. A plurality of radial plungers with inner ends coupled to the coupling ring are slidably fitted in respective cylinders that are rockably supported it the casing assembly. The angular movement of the eccentric collar on the crankpin is adjusted by a stroke adjusting mechanism. The coupling ring can be positioned with respect to the main shaft and the casing assembly by a W-mechanism. The W-mechanism may comprise external and internal gears or pulleys and sprockets.

Abstract: A rotary reciprocating engine has a rotating center shaft and a rotating outer rim with a rotational eccentricity in relation to the center shaft. The engine has a synchronization mechanism including a synchronizing hub, a guide rail, one cam member fitted to the center shaft, and another cam member fitted to the outer rim. The synchronization mechanism has the same rotational eccentricity in relation to the center shaft as the outer rim, but the rotational axes of the synchronization mechanism and the outer rim are on opposite sides of the rotational axis of the center shaft. The synchronization mechanism restrictively guides rotation of the center shaft and the outer rim, and transfers and balances the forces and moments generated by the pressure medium in the engine, leading to the pistons and cylinders being subjected to axially directed forces only and not moment transferring cross head forces.

Abstract: The invention relates to a valve-controlled positive displacement pump having valve triggering, which permits the forced opening or keeping open of an inlet valve, operating in the manner of a non-return valve, of a displacer working space, so that the displacer working space remains connected to the inlet side of the unit even during the working stroke of the displacer, and the assigned displacer is not able to work efficiently. The design according to the invention is particularly suitable for radial piston pumps.

Abstract: A hydrostatic pump and motor combination is disclosed including a rotor having radially disposed cylinders containing reciprocatably disposed spherical balls therein. A free outer race is eccentrically disposed about the rotor to define either a pump or motor. The cylinders are tilted relative to the center of the rotor to reduce side torque thrust loads on the cylinders. Also disclosed are a hydrostatic pump and motor including matching spherical slipper shoes and spherical free outer race. Hydrostatic thrust cups are disposed within the cylinders to reduce frictional losses, wear, and leakage. The thrust cups include hydrostatic means for supporting the balls in the cylinders, thereby self adjusting in response to fluid pressure and centrifugal loads.

Abstract: A variable capacity hydraulic constant stroke piston apparatus has an annular rotor rotatably mounted for rotation around an axis of rotation and having a plurality of radial cylinder bores therein spaced at intervals therearound with working liquid inlets and outlets at the radially outer ends thereof, a rotor drive for rotating said rotor around the axis of rotation, an eccentric cam positioned within the rotor and movable along a circular locus of eccentric positions concentric with said axis of rotation; a device for fixing the eccentric cam at one of the plurality of eccentric positions and for moving the eccentric cam around the axis of rotation between said positions; a plurality of pistons radially reciprocally movably mounted in corresponding cylinder bores in the rotor, the pistons having heads normally contacting an outer periphery of the eccentric cam and moving through a constant length stroke at each position of the cam; and working liquid current rectifying means connected between the inlets an