Pump

Abstract

Pump comprising a receiving housing (20) which forms a pot-shaped receiving chamber (25) with an end wall (20c) and a circumferential wall (20d), a pump insert (1) which is arranged in the receiving chamber (25), wherein the pump insert (1) comprises: - a rotor (4) and a pump shaft (10), - a first housing part (2) and a second housing part (3) between which the rotor (4) is rotatably arranged about an axis of rotation (D) and relative to the first and second housing parts (2, 3), wherein the pump shaft (10) is non-rotatably connected to the rotor (4) and is rotatably mounted in the first housing part (2) and in a sack-shaped recess of the second housing part (3), - a piston ring (12) which surrounds the rotor (4) and is arranged between the first housing part (2) and the second housing part (3), wherein a second seal (8), in particular a sealing ring, is located between the receiving housing (20) and the second housing part (3). is arrangedwhich seals a first pressure chamber (23b), formed between the end wall (20c) and the second housing part (3), with respect to a suction chamber (24), formed between the circumferential wall (20d) and the hub ring (12), and a first seal (7), which for example seals the suction chamber (24) to the outside or to the opening of the receiving housing (20), is arranged between the first housing part (2) and the receiving housing (20), in particular the circumferential wall (20d) of the receiving housing (20), wherein the suction chamber (24) is formed between the first seal (7) and the second seal (8), and a sealing element (9) is arranged between the second housing part (3) and the end wall (20c) of the receiving housing (20), which surrounds a second pressure chamber (23c) in an annular manner.

Description

[0001] The invention relates to a pump, in particular a positive displacement pump for a liquid, such as oil. The pump can be designed, for example, as a vane pump or rotary vane pump, an internal or external gear pump, a pendulum vane pump, or a roller vane pump. The pump is particularly suitable for installation in a vehicle, such as a motor vehicle, and / or for supplying a consumer in a motor vehicle. The consumer can be, for example, an internal combustion engine, a transmission, such as a steering gear, or an automatic transmission. A first aspect relates to the support of a spring that acts between a receiving housing and a pump insert inserted in the receiving housing. A second aspect relates to the combination of a seal with a spring acting between the receiving housing and the pump insert. A third aspect relates to the sealing of pressure chambers of a multi-stroke pump from one another.Each of the aspects mentioned can, but does not necessarily have to, be combined with one or more of the other aspects mentioned or their further training.

[0002] WO 2013 / 185751 A1 discloses a so-called cartridge pump which has a pump assembly or pump insert which essentially consists of a rotor, a cam ring, a pressure plate, press pins and a spring element. The rotor is rotatably received between the pressure plate and the side plate and is surrounded by the cam ring, which is also arranged between the pressure plate and the side plate. Several press pins which are pressed axially fixed into the pressure plate and penetrate the side plate and the cam ring secure the pressure plate, the side plate and the cam ring in a rotationally and axially fixed manner to one another. The spring element is attached to the pressure plate on the end face of the pressure plate facing away from the rotor. The pump insert is inserted into a pot-shaped housing, with the spring element being supported on the bottom or an end wall of the pot-shaped housing.The housing is closed by a housing cover, which holds the pump insert in its installed position. The spring element rests with two spring tongues on a cold start plate, which in turn rests on the pressure plate 17. The pump has a seal arranged between the end wall and the pressure plate, which seals off a first pressure chamber and a second pressure chamber from each other, with the pressure chambers being arranged between the end wall and the pressure plate. The seal is a separate part from the spring element.

[0003] EP 0 415 089 A2 describes an axial seal with a locking ring and a sealing ring attached to it in one piece. The locking ring consists of a thermoplastic with an extrusion-resistant core and a slightly flexible surface which is pressed against the wall of the gap to be sealed by the compressed sealing ring and the oil pressure. A pump insert arranged in a pot-shaped pump housing part has a pressure plate, with the axial seal arranged between the pressure plate and an end wall of the pump housing part. A valve spring, separate from the axial seal, acts between an end wall of the pump housing part and the pressure plate. The valve spring is supported on the pressure plate via a valve. The valve is supported centrally, i.e. in the region of a rotational axis of a rotor of the pump insert, on the pressure plate.EP 0 415 089 A2 shows designs with one or more axial seals, wherein the axial seal(s) seal a suction-side region from a pressure-side region. The suction-side region and the pressure-side region are arranged between the end wall and the pressure plate.

[0004] DE 24 23 474 A1 discloses a vane pump with a drive shaft mounted in a cantilevered pump housing. The drive shaft is connected to a rotor of the pump in a rotationally fixed manner.

[0005] US 6,358,020 B1 and US 6,499,964 B2 show cartridge pumps in which a cam ring and two housing plates are positioned relative to each other by means of pins and held together with a rotor to form a pump unit. A motor shaft can be inserted into the pump unit and connected to the rotor in a rotationally fixed manner. Cartridge pumps supply fluid to a consumer.

[0006] The first aspect is based on the task of avoiding, as far as possible, adverse deformation of the pump cover and / or the end wall of the housing caused by the spring force. The second aspect is based on the task of facilitating the assembly of the pump insert into the housing.

[0007] The invention is based on the object of providing a space-saving pump that can supply various fluid circuits with pressurized fluid. This object is achieved with a pump according to claim 1.

[0008] The invention is based on a pump, in particular a positive displacement pump, such as a vane pump, rotary vane pump, gear pump, pendulum vane pump, or roller vane pump. The pump comprises a receiving housing forming a cup-shaped receiving space with an end wall and a peripheral wall, and a pump insert inserted into the receiving space as a unit that can be handled separately from the receiving housing. The pump insert can be supported or centered on the peripheral wall of the cup-shaped receiving space, or can form at least one circumferential sealing gap with the peripheral wall. The pump insert can thus be guided by the peripheral wall.

[0009] The pump insert comprises a housing which encloses a pump chamber. In the pump chamber, a rotor is arranged so as to be rotatable about an axis of rotation relative to the housing. The pump comprises the rotor and at least a first housing part, in particular a first housing cover, and a second housing part, in particular a second housing cover, between which the rotor is arranged so as to be rotatable about an axis of rotation relative to the first and second housing parts. The rotor can be connected or connectable directly or indirectly to a pump shaft in a torque-transmitting manner, for example via a shaft-hub connection. When the pump shaft is rotated relative to the first and second housing parts, the rotor rotates with it. The rotor has recesses, in particular guides, such as slot-shaped recesses or guides, in which conveying elements, such as vanes, sliders or rollers, are accommodated so as to be movable, in particular displaceable, radially to the axis of rotation.The conveying elements are mounted or supported by the rotor in such a way that they rotate with the rotor around its axis of rotation. In particular, each of the conveying elements is mounted in its guide with a single translational degree of freedom.

[0010] The pump shaft can extend through the housing and be mounted on the housing for rotation about the axis of rotation, for example with a first section on the first housing part and with a second section on the second housing part. An external structure for the shaft-hub connection can be formed between the first section and the second section of the pump shaft. The rotor and the pump shaft can be connected in a rotationally fixed manner by means of a shaft-hub connection, for example with straight teeth. The shaft-hub connection has an internal toothing with a plurality of teeth and an external toothing with a plurality of teeth that engages with the internal toothing.

[0011] A third housing part, namely a cam ring, is arranged between the first housing part and the second housing part. The cam ring surrounds the rotor around its circumference. The cam ring can be a separate part from the first and second housing parts. Alternatively, the cam ring can be a section of the first housing part formed by the first housing part or a section of the second housing part formed by the second housing part. The first housing part or the second housing part or both can surround the rotor and in particular its impelling elements, for example, in an annular manner if the cam ring is part of the first or second housing part.

[0012] The first housing part, the second housing part, and the cam ring enclose and delimit a pump chamber in which the rotor and the pumping elements are arranged. A first pumping chamber and a second pumping chamber are formed radially between the cam ring and the rotor, which is rotatably enclosed between the first and second housing parts, in a double-stroke pump.

[0013] Between adjacent pumping elements, a pumping cell is formed, which is circumferentially bounded by an inner circumferential surface of the cam ring and, in the direction of the rotational axis, by the first housing part on one side and by the second housing part on the other side. The volume of the pumping cell changes depending on the rotational position of the rotor about its rotational axis. The pump has a plurality of pumping elements and thus, in particular, an identical plurality of pumping cells formed between the pumping elements.

[0014] The inner circumference of the cam ring has a contour along which the conveying elements slide as the rotor rotates. The contour is designed in particular so that the volumes of the conveying cells moving through the conveying chamber due to the rotor's rotation initially increase and then decrease. During one complete rotation of the rotor, the conveying elements are moved away from the axis of rotation and toward the axis of rotation at least once. The pump is double-stroke, i.e., it is designed with a first conveying chamber and a second conveying chamber, each of which the conveying elements or the conveying cells pass through once during one complete rotation. This means that during one complete rotation, the conveying elements are alternately moved away from the axis of rotation twice and toward the axis of rotation twice. During one rotation of the rotor, the volume of a conveying cell initially increases and then decreases.

[0015] The pump or pump insert can have at least one inlet channel that opens into the area of the delivery chamber in which the volume increase of the delivery cell takes place, and at least one outlet channel that opens into the area of the delivery chamber in which the volume reduction of this delivery cell takes place. Due to the volume increase of the delivery cell, the at least one inlet channel acts as a suction channel. Due to the volume reduction, the at least one outlet channel acts as a pressure channel. A single-stroke pump can, for example, have one inlet channel and one outlet channel. A double-stroke pump can, for example, have a common inlet channel for the first and second delivery chambers and a first outlet channel for the first delivery chamber and a separate second outlet channel for the second delivery chamber.In an alternative, the pump insert can have a first inlet channel for the first delivery chamber and a separate second inlet channel for the second delivery chamber and a first outlet channel for the first delivery chamber and a separate second outlet channel for the second delivery chamber or a common outlet channel for the first and second delivery chamber. The fluid delivered via the first delivery chamber can, for example, supply different consumers or the same consumers as the fluid delivered via the second delivery chamber. When supplying different consumers, different pressure levels can arise between the first outlet channel and the second outlet channel or between the first pressure chamber into which the first outlet channel opens and the second pressure chamber into which the second outlet channel opens. The delivery elements and / or the rotor each form a pressure gap with the first housing part and the second housing part.The at least one inlet channel can be connected to a fluid reservoir, such as an oil tank, in particular be fluidly connected. For example, the at least one suction channel can open into a suction chamber, which can be formed, for example, between the receiving housing and the pump insert, in particular between the peripheral wall of the receiving housing and the pump insert, such as the cam ring. The at least one outlet channel can be connected to at least one fluid consumer, such as being fluidly connected to a transmission.

[0016] The pump insert can have at least one positioning element, which positions the second housing part with respect to its angular position about the rotational axis relative to the first housing part. The at least one positioning element can be formed by the first housing part, in particular in one piece or monolithically. Alternatively, the at least one positioning element can be formed as a part separate from the first housing part, which is anchored in the first housing part. For example, the positioning element can be screwed or pressed into the first housing part, i.e., anchored in a form-fitting and / or force-fitting manner. Alternatively or additionally, the at least one positioning element can be anchored in the first housing part in a material-to-material manner, such as by being glued, soldered, or welded. The first housing part can have a bore for each positioning element, into which one end of the positioning element is inserted and thereby anchored in the first housing part. For example,Two, three, four or more positioning elements can be provided.

[0017] The at least one positioning element can, in particular, be pin-shaped or cylindrical. For example, the end of the positioning element opposite the anchored end can have the same outer diameter as the anchored end.

[0018] The second housing part and in particular also the cam ring can be mounted on the at least one positioning element in a manner secured against rotation about the rotation axis. The at least one positioning element can extend through a recess provided for each positioning element in the second housing part, such as a bore or through-hole. The at least one positioning element can extend, for example, through a recess in the cam ring, which can be designed, for example, as a bore, elongated hole, or the like.

[0019] In particular, the at least one positioning element can protrude from the second housing part with its end which is opposite the end anchored in the first housing part, in particular protrude from the end face of the second housing part which is opposite the end face which faces the rotor or which faces the end wall of the receiving housing.

[0020] The pump or pump insert can have a spring that is supported, for example, on the second housing part and on the bottom or end wall of the receiving housing. As mentioned, the receiving housing can be pot-shaped, for example. The peripheral wall of the receiving housing can extend around the rotational axis of the rotor. The end wall is arranged on the end side of the peripheral wall, so that the receiving housing is pot-shaped. The spring tensioned between the end wall and the pump insert tends to push the pump insert, in particular the second housing part, away from the end wall of the receiving housing.

[0021] Falling out of the pump insert from the receiving housing is prevented, for example, by a cover or an axial locking element. The spring, tensioned upon insertion, presses the pump insert, in particular the first housing part, against the axial locking element or the cover. The axial locking element or the cover prevents the spring from relaxing. The axial locking element can, for example, be annular and inserted into an annular groove formed on the preferably cylindrical circumference of the receiving housing. The axial locking element can be formed by a cover that at least partially or completely closes the opening.

[0022] The spring tensioned between the pump insert and the end wall exerts a force on the second housing part, directed away from the end wall and particularly along, i.e., in the direction of the rotor's rotational axis, which pushes the second housing part against the cam ring, which in turn pushes the cam ring against the first housing part. The cover or axial locking element forms the abutment for this. The spring force axially seals the cam ring with respect to the first and second housing parts, allowing pressure to build up in the discharge chamber or chambers when the pump starts up.

[0023] The spring can, in particular, be captively attached to the pump insert, in particular to the at least one positioning element or the second housing part. The spring can, for example, be connected to the positioning element or the second housing part in a form-fitting manner, in particular by snapping or force-fitting, so that the spring is held on the at least one positioning element or the second housing part and preferably is or can be supported on the second housing part. It is preferred that the spring is attached to the at least one positioning element or the second housing part in a manner secured against rotation about the axis of rotation, in particular by form-fitting and / or force-fitting. The spring can have or form at least one fastening element, in particular on or in the region of a support section, with which the spring is supported on the second housing part or on a part that is supported directly or indirectly on the second housing part. E.g.The at least one fastening element can serve as a support section, or a fastening element can be provided for each support section. The spring can be fastened or secured to the at least one positioning element or the second housing part by means of the fastening element. The fastening element, which is designed, for example, for a positive connection with its associated positioning element, can be snapped onto the positioning element.

[0024] The at least one positioning element can have a recess, such as an annular groove, around its circumference, into which the at least one fastening element of the spring engages. Such an annular groove can be designed as a recess. For example, the at least one fastening element can be designed in the shape of a lock washer or a circlip, similar to lock washers for shafts according to DIN 6799 or retaining rings for shafts according to DIN 471, in particular with the difference that they are formed by the spring, namely, they can be integrally formed on the support section.

[0025] In alternative embodiments, the securing element, in particular the locking washer designed, for example, according to DIN 6799 or the circlip designed, for example, according to DIN 471, can actually be a washer or a ring, i.e. it cannot be formed onto the spring and, for example, only serve to prevent the second housing part from being axially removed from the positioning element. In this embodiment, the spring can be fastened to the second housing part or to the securing element or can be enclosed between the securing element and the second housing part, wherein the fastening element of the spring can be plugged onto the positioning element. In alternative embodiments, the positioning element can, for example, be designed with a head, wherein the second housing part is enclosed between the first housing part and the head, thus preventing the second housing part from being removed from the first housing part or from the positioning element.In these embodiments, the spring can be attached to the second housing part or to the head or can be enclosed between the head and the second housing part, wherein the fastening element of the spring can be plugged onto the positioning element.

[0026] In further embodiments, the recess can be an annular groove extending over the circumference of the cylindrical or pin-shaped positioning element, which has a width extending along the longitudinal axis of the positioning element and is dimensioned such that the fastening element of the spring is received in the annular groove with a certain amount of play along the longitudinal axis. This ensures that the support section or the fastening section of the spring is supported on the second housing part and not on a groove flank of the annular groove.

[0027] In embodiments in which the spring is fastened to the second housing part, the second housing part can have a groove on an inner circumferential surface or an outer circumferential surface which runs at least partially or completely around the axis of rotation of the rotor and is open inwards or outwards, wherein the spring, i.e. one or more sections of the spring, are fastened in the groove to the second housing part, in particular are enclosed by the groove. The groove width is somewhat greater than the thickness of the sections of the spring which are arranged in the groove for fastening. For example, the spring can be elastically compressed laterally for insertion into the groove, wherein the spring is placed in the immediate vicinity of the groove and then released. Due to the elasticity of the spring, it returns to its original shape, whereby the spring or sections thereof engage in the groove and fasten the spring captively to the second housing part.For example, in the relaxed state, the spring may have an oval shape or projections forming said sections, with the circumferential groove or annular groove extending in a circle around the axis of rotation.

[0028] The pump has a pump shaft that is rotationally fixedly connected to the rotor and rotatable about the rotation axis. The pump shaft is rotatably mounted in the first housing part. Additionally, the pump shaft is rotatably mounted in the second housing part, particularly in a pocket-shaped recess in the second housing part. The pocket-shaped recess has the advantage that the pump chamber is sealed off from the end face of the second housing part facing away from the pump chamber. The bearing(s) can be plain or rolling bearings.

[0029] The pump shaft may have a structure, in particular external gearing, for a shaft-hub connection with the rotor. The diameter of the structure may be larger than the inner diameter of the first housing part and / or the second housing part or the bearings. The structure is thus enclosed between the first housing part and the second housing part along, i.e., in the direction of the rotation axis. This ensures that the shaft cannot be pulled out of the fully assembled pump insert.

[0030] In particular, the first housing part, the second housing part, the cam ring, the rotor, the conveying elements, the positioning elements, the spring, and the pump shaft can essentially form the pump insert, which can be handled as a unit. By attaching the spring to the at least one positioning element, disintegration of the pump insert can be prevented. The fastening sections of the spring and / or the locking elements separate from the spring provide axial shaft locking, preventing the pump insert from disintegrating.

[0031] Due to the easy handling of the pump insert, it can be inserted into the receiving housing, which can be formed, for example, by a gearbox housing for a motor vehicle, via an opening in the receiving housing opposite the front wall.

[0032] A second seal, in particular a sealing ring, is arranged between the second housing part and the receiving housing, in particular the peripheral wall, which seals a pressure chamber formed between the end wall and the second housing part with respect to a suction chamber formed between the peripheral wall and the first housing part and / or the cam ring. For example, the pressure chamber can be connected to the at least one delivery chamber by means of the at least one outlet channel.

[0033] A first seal, in particular a sealing ring, is arranged between the first housing part and the receiving housing, in particular the peripheral wall, with the suction chamber being arranged between the first and second seals. The first seal can seal the suction chamber to the outside or to the opening of the receiving housing.

[0034] Because the at least one pressure chamber is arranged between the end wall and the second housing part, the second housing part acts like a piston which, when the pressure in the pressure chamber increases, increases the force along or in the direction of the axis of rotation on the axial securing element or the cover and thus also presses the parts of the pump insert, in particular the first housing part, the second housing part and the stroke ring, together in a sealing manner, with an increasing force as the delivery pressure increases and in particular in addition to the force of the pre-tensioned spring.

[0035] According to the first aspect, the spring, which is resiliently arranged, in particular tensioned, between the receiving housing and the second housing is supported towards the second housing part essentially in an area which is arranged in axial alignment with the cam ring in the direction of the axis of rotation of the rotor, and as a result, i.e. due to the support in alignment with the cam ring, presses the second housing part against the cam ring. In alignment means in an imaginary axial extension of the wall of the cam ring along or in the direction of the axis of rotation. In WO 2013 / 185751 A1, the spring element is supported with its two spring tongues on a cold start plate and in an area which lies outside the axial alignment with the cam ring, namely within the inner contour of the cam ring.The radial distance between the area where the spring is supported and the cam ring creates a moment that leads to a deformation of the cover, albeit only slight. This, however, increases the friction of the rotor on the cover or, alternatively, requires a relatively large sealing gap, which reduces the pump's efficiency. In EP 0 415 089 A2, the valve spring is supported on the pressure plate via the valve, with the area also lying within the internal dimensions of the cam ring, which can also lead to small deformations in the cover. The support according to the first aspect prevents such deformations, thereby increasing the pump's efficiency.

[0036] In particular, the spring can have a spring structure made of metal, especially steel or spring steel, wherein the metal spring structure imparts its essential spring property along or in the direction of the rotational axis. This means that the spring can, for example, be coated or overmolded with another material that also has a spring property, although this is negligible compared to the metal spring structure.

[0037] The spring can be supported directly or indirectly on the second housing part. For example, an intermediate part can be arranged between the second housing part and the spring, with the spring being supported on the intermediate part. In particular, the intermediate part can be supported on the second housing part, preferably also in a region that is arranged in axial alignment with the cam ring in the direction of the rotation axis.

[0038] The intermediate part can, for example, have or be a so-called cold start plate or a plate-shaped structure, such as a perforated (metal) sheet or a sieve structure. The intermediate part can, for example, be enclosed or arranged between the spring and the second housing part and / or be held or fastened to the at least one positioning element, such as, for example, having a recess or bore for each positioning element to which it is fastened, through which the respective positioning element extends. The intermediate part can have at least one region with the sieve-shaped structure or at least one perforated region, such as, for example, a single, two or more such regions. The intermediate part is, in particular, arranged such that the at least one region is flowed through by the liquid conveyed from the at least one conveying chamber. Through the - although, for example,low - flow resistance, which is caused by the at least one area when flowing through, the pressure increases on the inflow side, ie on the side of the intermediate part, which is flowed by the liquid from the at least one delivery chamber.

[0039] On the upstream side of the intermediate part, the pump insert, in particular the second housing part, has at least one connecting channel that supplies the undervane chambers, i.e., the chambers formed in the slots in which the vanes are guided and extending radially between one end of the respective vane and the base of the respective slot, with the fluid pumped from the at least one pumping chamber. The dynamic pressure generated by the flow-through area of the intermediate part causes the vanes to extend more quickly during cold starts and thus generally results in a faster pressure buildup by the pump.The intermediate part and / or the spring, on which the intermediate part can be supported, for example, in a resilient manner, can, alternatively or in addition to the sieve-shaped or perforated structure, be designed to be so flexibly resilient that the intermediate part lifts off at least partially from the second housing part when a limit pressure is reached, whereby liquid can flow from the delivery chamber through a gap formed thereby between the intermediate part and the second housing part.

[0040] For example, the spring, in particular with its end pointing towards the receiving housing or the end wall, can be supported essentially in an area on the receiving housing, in particular on the end wall, which is arranged in axial alignment with the cam ring in the direction of the axis of rotation. One advantage of this is that deformation of the end wall due to the spring force can be avoided. A further advantage is that the cross section which the spring surrounds, in particular in a ring shape, has a relatively large diameter, in particular approximately at least the inner diameter or the smallest inner diameter of the cam ring. This advantageously ensures that the cross section surrounded by the spring is relatively large and thus offers the possibility of sealingly arranging a seal, in particular an annular seal, between the second housing part and the end wall of the receiving housing, for example.to seal a second pressure chamber from a first pressure chamber. Accordingly, a sealing element can be arranged between the second housing part and the end wall of the receiving housing, which sealing element surrounds the pressure chamber, in particular in a ring shape. In particular, the spring can be ring-shaped and at least partially surround a pressure chamber, in particular a first pressure chamber, which is connected to the delivery chamber, in particular the first delivery chamber, via the outlet channel formed by the second housing part, in particular the first outlet channel. In particular, the spring can be arranged in the first pressure chamber.

[0041] In particular, the seal, which is also referred to herein as a sealing element, can surround the second pressure chamber in a ring-shaped manner, wherein the first pressure chamber formed between the end wall of the receiving housing and the second housing part is sealed off from the second pressure chamber by means of the sealing element. As already mentioned, the first pressure chamber can be connected to different fluid consumers via a first supply branch than the second pressure chamber, which is connected to fluid consumers via a second supply branch that is separate from the first supply branch. Alternatively, it is possible to supply one or more common fluid consumers with fluid from the first pressure chamber and the second pressure chamber via separate supply branches, namely the first supply branch and the second supply branch.

[0042] The spring arranged between the end wall and the second housing part can be, for example, a corrugated ring spring, a multi-corrugated spring washer, a hose or arc spring, a grooved ring spring, a (metal) C-ring or a (metal) O-ring.

[0043] A multi-wave spring washer can have or consist of a spring structure made of metal, in particular steel, wherein the spring structure is formed from a flat or round material which forms a closed ring, in particular. The spring is waved over the circumferential direction of the ring, at least in the unloaded state, i.e., it is wave-shaped or has multiple waves, in particular multiple wave crests and wave troughs. The wave height extends along or in the direction of the axis of rotation or essentially perpendicular or normal to the plane spanned by the ring-shaped spring structure. The multi-wave spring has the advantage that it can be used in a very space-saving manner.

[0044] A corrugated spring can have or consist of a spring structure formed from a flat or round material, which winds helically around a longitudinal spring axis along a circumferential direction, wherein the spring structure is undulated in the circumferential direction or has a plurality of waves, i.e. a plurality of wave crests and wave troughs. The spring structure can wind partially, completely or multiple times around the longitudinal spring axis, in particular in an approximately undulating helical shape. Adjacent turns can abut one another with their wave crests and wave troughs or can be fastened to one another. This means that one turn rests with its wave crest on the wave trough of the next following turn. The spring structure can have an initial turn and / or an end turn, wherein the initial turn and / or the end turn extend essentially flat around the longitudinal spring axis.With the initial coil and / or the final coil, the spring can be supported on the end wall and / or directly or indirectly on the second housing part. The initial coil and the final coil ensure a better contact, i.e., a more even distribution of the spring force on the parts against which the spring rests. The spring's longitudinal axis is parallel to or lies on the rotational axis. For example, the initial coil can have the fastening element for attachment to the positioning element.

[0045] A (metal) C-ring or a (metal) O-ring is annular. The spring structure extends at least in sections over the circumference of the spring's longitudinal axis. The spring's longitudinal axis is perpendicular or normal to the surface spanned by the ring. The spring's longitudinal axis is substantially parallel to or lies on the rotor's axis of rotation. The ring can be flat or substantially non-corrugated over its circumference. In the case of a (metal) C-ring, the spring structure is C-shaped in cross-section, which is transverse to the circumferential direction, i.e. with an open contour, and in the case of a (metal) O-ring, it is O-shaped, i.e. with a closed contour. Between adjacent sections which have a C- or O-ring-shaped spring structure, a fastening element for fastening to the positioning element can be formed. The springs mentioned herein can have multiple fastening elements for multiple positioning elements.

[0046] In a second aspect of the invention, an annular sealing element (seal or axial seal) is arranged between the end wall and the second housing part, in particular the sealing element described generally and / or in relation to the first aspect, which encloses a pressure chamber formed between the end wall and the second housing part, in particular the second pressure chamber, wherein the pressure chamber is connected via an outlet channel to a delivery chamber formed between the rotor and the cam ring. The spring has a spring structure made of metal, in particular spring steel, which imparts its essential spring property to the spring structure, wherein the annular sealing element is fastened, in particular captively fastened, to the spring structure. Thus, the spring and the sealing element can form a unit or integral unit that can be handled as a unit. E.g.When attaching the spring to the second housing part or to the at least one positioning element, the sealing element can also be arranged at the location provided for the sealing element on the second housing part. The advantage of this is that the spring and the sealing element can be attached to the pump insert in one work step. Furthermore, it is advantageously achieved that the sealing element is fixed when the pump insert is inserted into the receiving housing and cannot slip or fall out. This facilitates the assembly of the pump insert in the receiving housing. The sealing element can be attached to the spring element, for example by encasing or molding the sealing element onto the spring or the spring structure. Alternatively, the seal referred to as the sealing element can be attached to the spring structure in a form-fitting manner, for example by plugging it on, or in a force-fitting manner, for example by clamping it on.

[0047] The spring structure can, for example, have an additional annular section that is part of the sealing element and is overmolded or coated with a sealing material, such as a polymer or elastomer. The additional annular section acts as a support structure that counteracts extrusion or gap extrusion of the sealing material of the sealing element due to the pressure difference between the first pressure chamber and the second pressure chamber.

[0048] The spring structure can have a further annular portion that is also overmolded or coated with the sealing material. This additional annular portion can annularly surround the rotational axis of the rotor, in particular the pump shaft when it extends through the second housing part, in order to seal the first pressure chamber and / or the second pressure chamber with respect to the pump shaft.

[0049] The seal or sealing element surrounding the second pressure chamber is preferably arranged eccentrically to the axis of rotation of the rotor, in particular in a region between the annular spring, which at least partially surrounds the first pressure chamber, and the pump shaft or a region which is arranged in axial alignment with the pump shaft in the direction of the axis of rotation.

[0050] In a third aspect, a first pressure chamber and a second pressure chamber are formed between the end wall and the second housing part, as already described above. An annular sealing element, as already described, is arranged between the end wall and the second housing part, which encloses the second pressure chamber and seals it off with respect to the first pressure chamber. The first pressure chamber is connected via a first outlet channel to a first delivery chamber formed between the rotor and the cam ring, and the second pressure chamber is connected via a second outlet channel to a second delivery chamber formed between the rotor and the cam ring. As a result, as described above, different or common consumers can be supplied with fluid via separate supply branches, wherein different pressures can develop in the first and second pressure chambers.

[0051] The invention has been described using several examples and embodiments. Particularly preferred embodiments of the invention are described with reference to the figures. They show: Figure 1 shows a section through a rotational axis of a rotor, wherein a pump insert is shown inserted into a receiving housing, Figure 2 shows a sectional view of the pump insert from Figure 1 through the rotation axis, Figure 3 a perspective view of the pump insert from Figure 2, Figures 4 and 5 Embodiments of a spring for the pump assembly, Figure 6 another embodiment of a spring for the pump assembly, Figure 7 another embodiment of a spring for the pump assembly with an O-ring-shaped cross-section, Figure 8 another embodiment of a spring for the pump assembly with a C-ring-shaped cross-section, Figure 9 another embodiment of a seal arranged between the pump assembly and the receiving housing, Figure 10 another embodiment of a seal, Figure 11 another embodiment of a seal, Figure 12 another embodiment of a seal, Figure 13 another embodiment of a seal, Figure 14 another embodiment of a seal, Figure 15 another embodiment of a seal, Figure 16 another embodiment of a seal, Figure 17 a pump insert in section along the axis of rotation of the rotor, wherein the pump insert comprises a spring,which is combined with a seal, Figure 18 shows a perspective view of the pump insert from , Figure 17 , Figure 19Representations of the spring combined with the seal and Figure 20an exemplary cross-section through a pump insert in the area of the rotor.

[0052] The Figures 2 , 3 , 17 and 18 show pump inserts that can be inserted into a housing, as in Figure 1 The pump, in particular the pump insert 1, comprises a spring 5, which is shown here in various embodiments. The pump or the pump insert 1 has a seal 9, in particular an axial seal, arranged between an end wall 20c of a receiving housing 20 and a second housing part 3. The seal 9 is shown in various embodiments partly combined with the spring 5.

[0053] The pump or pump insert 1 comprises a rotor 4, which is connected to a pump shaft 10 in a rotationally fixed manner via a shaft-hub connection 30. The rotor 4 comprises recesses, in particular slot-shaped, serving as guides. Each recess is assigned a conveying element 13, in particular a vane. The vane 13 is displaceable radially at its recess or away from the rotational axis D of the rotor 4 and towards the rotational axis D of the rotor 4, in particular guided with a single translational degree of freedom, displaceable back and forth, as for example from Figure 20can be seen. The vanes 13 rotate with the rotor 4. The pump 1 has an annular housing part, namely a cam ring 12. The cam ring 12 is enclosed between a first housing part 2 and a second housing part 3 and is rotationally fixed with respect to the first and second housing parts 2, 3. The space extending annularly around the pump shaft 10, which is surrounded by the inner circumference of the cam ring 12 and axially delimited by the second and third housing parts 2, 3, can also be referred to as the pump chamber 26. The rotor 4 and the vanes 13 are arranged in the pump chamber 26.

[0054] How best to Figure 20 As can be seen, at least one delivery chamber 27, 28 is formed radially between the rotor 4 and the cam ring 12. The embodiment shown here comprises two delivery chambers 27, 28, namely a first delivery chamber 27 and a second delivery chamber 28 ( Figure 20 ).

[0055] Between adjacent vanes 13, a delivery cell 29 is formed, the volume of which changes depending on the rotational position of the rotor 4 about its rotational axis D. Since the pump has several vanes 13, it also has a corresponding number of delivery cells 29. Several delivery cells 29 are located in each of the delivery chambers 27, 28.

[0056] The vanes 13 and the rotor 4 form a first sealing gap with the first housing part 2 and a second sealing gap with the second housing part 3.

[0057] The cam ring 12 and / or the vanes 13 can be magnetized, so that the vanes 13 rest against the inner circumferential surface of the cam ring 12 due to magnetic force, in particular even when the rotor 4 is not rotating. This allows early pressure buildup during start-up or cold start, i.e., when the pump shaft 10 begins to rotate. Alternatively or additionally, the vanes 13 can be pressed outwards, i.e., away from the axis of rotation of the rotor 4, against the inner circumferential surface of the cam ring 12 due to centrifugal force as the rotor rotates. The vanes 13, or each of the vanes 13, forms a third sealing gap with the inner circumferential surface of the cam ring 12.

[0058] The inner circumferential surface of the cam ring 12 has a contour which causes the vanes 13 to extend at least once (increasing the volume of the delivery cell 29) and retract once (reducing the volume of the delivery cell 29) during one full rotation of the rotor 4. The pump shown in the example is double-stroke, i.e. with two delivery chambers 27, 28, with the vanes 13 extending once and retracting once for each delivery chamber 27, 28 when they are moved through the delivery chamber 27, 28 by rotation of the rotor 4. This causes the vanes 13 to extend, retract, extend and retract again during one full rotation of the rotor 4, or in other words, extend twice and retract twice. Between adjacent vanes 13, a conveying cell 29 is formed, the volume of which increases or decreases by the extension and retraction of the vanes 13 defining this conveying cell 29, namely depending on the contour of the inner circumferential surface of the cam ring 12.

[0059] As is particularly evident from Figure 3 As can be seen, the pump insert 1 has a first outlet channel 3b and a second outlet channel 3c, wherein the first outlet channel 3b is divided into a first pressure chamber 23b and a first delivery chamber 27 ( Figure 20 ) and thus connects the first delivery chamber 27 and the first pressure chamber 23b in a fluid-conducting manner. The second outlet channel 3c opens into a second delivery chamber 28 and the second pressure chamber 23c, thereby connecting the second delivery chamber 28 ( Figure 20 ) and the second pressure chamber 23c in a fluid-conducting manner. The first and second outlet channels 3b, 3c each open into the region of their respective delivery chambers 27, 28, in which the volume of the delivery cells 29 decreases during the rotation of the rotor 4. This causes fluid, such as oil, located in the delivery cells 29 to be displaced through the outlet channels 3b, 3c.

[0060] The pump insert 1 has a first inlet channel 2b and a second inlet channel 2c, wherein the first inlet channel 2b opens into the first delivery chamber 27 and a suction chamber 24 and thus connects the first delivery chamber 27 and the suction chamber 24 in a fluid-conducting manner, and wherein the second inlet channel 2c opens into the second delivery chamber 28 and the suction chamber 24 and thus connects the second delivery chamber 28 and the suction chamber 24 in a fluid-conducting manner. The first and second inlet channels 2b, 2c each open into the region of their respective delivery chamber 27, 28 in which the volume of the delivery cells 29 increases during the rotation of the rotor 4. This causes fluid to be conveyed or sucked through the first and second inlet channels 2b, 2c into the expanding delivery cell 29.

[0061] When the rotor 4 rotates, fluid, in particular liquid, is sucked through the channel 2b, 2c into the enlarging conveying cell 29 and transported to the area into which the outlet channel 3b, 3c opens, wherein the fluid is discharged from the then decreasing conveying cells 29 via the first outlet channel 3b or the second outlet channel 3c.

[0062] The pump insert 1 comprises at least one positioning element 6, in the example shown, two positioned elements 6. The positioning elements 6 are pins or pin-shaped. The positioning element 6 is firmly anchored in the first housing part 2. The first housing part 2 has a blind bore 2a into which the pin-shaped positioning element 6 is pressed with a first end.

[0063] The pin-shaped positioning element 6 positions the second housing part 3 and the cam ring 12 with respect to their angular positions around the axis of rotation D relative to the first housing part 2. The second housing part 3 and the cam ring 12 have recesses, openings, bores or elongated holes, preferably with a radial extension, through which the positioning element 6 extends. In the example shown, the cam ring 12 has a bore 12a for the first positioning element 6 and a further bore 12a for the second positioning element 6. The second housing part 3 has a through-bore through which the positioning element 6 extends. The positioning element 6 projects with its pin-shaped second end beyond the end face facing away from the pump chamber 26. This projecting section of the positioning element 6 has a recess, such as an annular groove 6a, or at least a part thereof, which extends over the circumference of the positioning element 6.A securing element or fastening element 5a of the spring 5 is arranged in the recess 6a, which is fastened, in particular, in a force-fitting and / or form-fitting manner to the positioning element 6 or in the annular groove 6a. The fastening element 5a prevents the first housing part 2, the second housing part 3, and the cam ring 12 from axially separating, or in other words, the second housing part 3 and the cam ring 12 from being pulled off the positioning element 6. This also securely fastens the spring 5 to the pump insert 1, in particular to the positioning elements 6.

[0064] The pump shaft 10 is rotatably mounted on the first and second housing parts 2, 3, in particular by means of a plain bearing each. As an alternative to a pump shaft 10 mounted on both sides, this can operate without the bearings in the second housing part 3 or only with the bearings in the first housing part 2, particularly if the pump insert 1 is double-stroke, i.e., has two delivery chambers 27, 28 opposite each other, for example, with respect to the rotational axis D. The forces caused by the pressures in the delivery chambers 27, 28, acting transversely to the rotational axis D, can essentially cancel each other out.

[0065] Between the section of the pump shaft 10 that is rotatably mounted in the second housing part 3 and the section of the pump shaft 10 that is rotatably mounted on the first housing part 2, an external structure, such as external gearing on the pump shaft 10, is formed, which is in positive engagement with a corresponding internal structure, in particular internal gearing of the rotor 4, in order to form a shaft-hub connection 30. The outer diameter of the outer structure of the pump shaft 10 is larger than the diameter of the section of the pump shaft 10 that is mounted in the first housing part 2 and / or in the second housing part 3. The pump shaft 10 is arranged in an axially fixed manner between the first and second housing parts 2, 3, i.e., a displacement of the pump shaft 10 along or in the direction of the axis of rotation D in both directions is essentially not possible.For this purpose, the outer diameter of the sections of the first housing part 2 and the second housing part 3, which support the pump shaft 10, is smaller than the outer diameter of the outer structure of the pump shaft 10.

[0066] The first housing part 2 has an annular pocket on its end facing away from the pump chamber 26, in which a shaft seal 11 is arranged. The shaft seal 11 is non-rotatably attached to the first housing part 2 and forms a sealing gap with the pump shaft 10. The shaft seal 11 seals the pump chamber 26 to the outside.

[0067] The end of the pump shaft 10, which is opposite the end arranged in the region of the spring 5, has an outer contour for a shaft-hub connection 30 with a drive wheel, in particular a gear 21, in particular a sprocket. The gear 21 is seated on the pump shaft 10 in a rotationally fixed manner. The gear 21 can be driven by a chain, which in turn is driven by, for example, a crankshaft or another shaft that can be connected to, for example, an engine of the vehicle. For its attachment to the pump shaft 10, the gear 21 has, for example, an internal thread with which it is screwed against a shoulder of the pump shaft 10 with an external thread of the pump shaft 10. A rotation lock seated on the shaft 10 secures the gear 21 against accidental loosening. Alternatively, the drive wheel 21 can be joined to the pump shaft 10 or fastened to it by means of an interference fit or other type of connection.

[0068] In the examples shown, the pump insert 1 is inserted into a pot-shaped housing 20, such as a housing pot ( Figure 1 ). The receiving housing 20 has a peripheral wall 20d, which circumferentially surrounds one of the pump inserts 1 shown therein. Furthermore, the receiving housing 20 has an end wall 20c, which is monolithically connected to the peripheral wall 20d, wherein the spring 5 is supported on the end wall 20c, in particular axially, i.e., in the direction of the rotation axis D.

[0069] The pump insert 1 is held between the end wall 20c and an axial locking element, such as a screw, an axial locking ring, or a cover, such that the spring 5 is or remains tensioned, in particular is or remains tensioned under pressure. In particular, the axial locking element can bear against the first housing part 2 and / or hold the first housing part 2 fixedly against displacement along or in the direction of the rotation axis D on the receiving housing 20.

[0070] The first pressure chamber 23b, into which the fluid (liquid) delivered by the pump is pumped, is formed between the end wall 20c and a second seal 8, which is arranged in an annular groove formed on the outer circumference of the second housing part 3 and which forms a sealing gap with the peripheral wall 20d. The pressure chamber 23b is in turn connected to a fluid consumer, such as a lubricant consumer, in particular a gearbox, via a channel (not shown). An annular seal 9 is arranged between the end wall 20c and the second housing part 3, which annularly surrounds the second pressure chamber 23c and seals it off from the first pressure chamber 23b. The seal 9 thus forms a wall of the first pressure chamber 23b and the second pressure chamber 23c. The fluid delivered by the pump is pumped into the second pressure chamber 23c. The second pressure chamber 23c is in turn connected by means of a channel (not shown) to a fluid consumer, such asa lubricant consumer.

[0071] The seal 9 is arranged in a sealing groove or a sealing pocket of the second housing part 3, which surrounds one end of the second outlet channel 3c in a ring shape, wherein the groove base or the pocket base forms a sealing surface for the seal 9. The wall of the groove or pocket, which surrounds the seal in a ring shape, has a distance from the end wall 20c that is less than the height of the seal 9, in particular than the height of the first ring 9a, which is described further below. The first ring 9a, in particular its material, and / or the smaller gap width between the wall and the end wall 20c prevent gap extrusion of the seal 9. Gap extrusion can also be prevented by a support structure in the seal 9.

[0072] A suction chamber 24 is formed between the second seal 8 and the first seal 7, which is arranged in an annular groove on the outer circumference of the first housing part 2 and which forms a sealing gap with the peripheral wall. From this suction chamber, fluid is conveyed via the first delivery chamber 27 and the second delivery chamber 28 into the first pressure chamber 23b and the second pressure chamber 23c, respectively. The suction chamber 24 can be connected, for example, by means of a channel, to a reservoir for the fluid, into which, for example, the fluid consumed by the consumer can flow back. As the fluid is conveyed, the pressure in the pressure chambers 23b, 23c increases with increasing speed, whereby the second housing part 3, in addition to the preload force of the spring, firmly clamps the cam ring 12 between the first and second housing parts 2, 3. As a result, the first and second housing parts 2, 3 and the cam ring 12 are sealed from one another.The connection between the axial locking element and the first housing part 2 is designed to be so strong that it can withstand the axial force acting on the axial locking element, such as that caused by the pressure in the pressure chambers 23b, 23c, i.e., it will not break. In the example shown, the axial locking element is a housing cover that is attached to the receiving housing 20 and against which the first housing part 2 is axially supported.

[0073] For example, a suitably designed corrugated ring spring, a multi-corrugated spring washer, a tubular or curved spring, a grooved ring spring, a metal O-ring, or a metal C-ring can be considered as spring 5. If the spring 5 is to be attached to the positioning elements 6, the spring can have fastening elements 5a for its attachment to the positioning elements 6.

[0074] In Figure 4A first embodiment of a spring 5 is shown, which is designed as a corrugated ring spring. The corrugated ring spring 5 has an annular spring structure 5b, which is corrugated over its circumference, i.e., has several waves, i.e., wave crests and wave troughs. The wave crests can, for example, rest on the end wall 20c and the wave troughs on the second housing part 3. The wave height extends approximately parallel to the axis of rotation D. The spring 5 is made of a flat material, in particular punched out. The spring 5 has on its circumference several, here two, fastening elements 5a in the form of recesses open towards the inner circumference, which can be arranged in the annular groove 6a of a positioning element 6. The thickness of the flat material of the spring 5 is less than the groove width of the annular groove 6a. The spring 5 made of Figure 5 is identical to spring 5 from Figure 4 . The spring 5 from Figure 4It also features several inwardly projecting protrusions on its inner circumference. This allows the stress distribution in the spring to be evened out during deformation, and the spring preload and spring rate to be adjusted to suit requirements.

[0075] The spring 5 from Figure 6 essentially corresponds to the version from Figure 5 , wherein the spring structure 5b consists of Figure 6 more waves than the version from Figure 5 , ie, it is more corrugated. In addition, the spring structure 5b has a positioning element 5e, which can engage in a corresponding recess in the second housing part 3 in order to fix the spring 5 in the correct position to the positioning elements 6.

[0076] Figure 7shows an annular spring 5 which has a plurality of tubular sections 5f around its circumference, in this example two tubular sections 5f. Between adjacent tubular sections 5f, a fastening element 5a and in particular a flat section 5g in which the fastening element 5a is formed is arranged. The fastening element 5a is a recess open towards the inner circumference of the ring. The thickness of the flat section 5g is less than the groove width of the annular groove 6a of the positioning element 6. The flat section 5g can be formed by compressing and plastically deforming a previously continuous tubular section 5f. In the example shown, two fastening elements 5a and thus two flat sections 5g are present. Furthermore, the spring 5 has two tubular sections 5f, which are each connected at their ends via a flat section 5g provided with a fastening element 5a.

[0077] The embodiment from Figure 8 shows a spring 5 which is identical to the spring from Figure 7 is, with the exception of the design of the tubular sections 5f. The design from Figure 8 has C-shaped sections 5h instead of a tubular section 5f. Otherwise, the design from Figure 7 The C-shaped sections 5h each have a contour that is open in cross-section, namely a slot that extends over the circumference, in particular the inner circumference, of the annular spring structure.

[0078] The springs 5 or spring structures 5b from the Figures 4 to 8 are preferably made of metal, in particular spring steel. Additionally, the springs 5 can be coated or overmolded, in particular with a plastic, such as a polymer or elastomeric or thermoplastic material, or, for example, with a lacquer.

[0079] Figure 9shows an annular seal 9 which comprises a first sealing ring 9a made of a first material and a second sealing ring 9b made of a second material. The first ring 9a and the second ring 9b can be connected to one another integrally or as a single piece, in particular by a material fit. The first ring 9a serves to ensure the stability of the annular seal 9, with the second ring 9b primarily serving to ensure the sealing function. In principle, reference can be made here to EP 0 417 089 A2, which describes such integral sealing rings. A suitable material for the first ring 9a is plastic, in particular a thermoplastic plastic or thermoplastics, which can be selected with the necessary properties. Polytetrafluoroethylene (PTFE) is particularly suitable, the core strength of which can be further increased by inserting fibers, for example glass fibers, so that the axial seal can withstand considerable pressures.Ethylene tetrafluoroethylene copolymer (ETFE) is also a possible material for the first ring, especially since this material is easy to process. Polyterephthalate is also well suited for the intended purpose, as it can be easily vulcanized with the sealing ring. Polyamides, with or without a glass fiber insert, are also suitable for the intended purpose. The second ring 9b is preferably made of a plastic, in particular an elastomeric or rubber-elastic material or elastomer, which is preferably easy to vulcanize, does not tear, and is not particularly sensitive to notches. The materials listed apply in particular, but not exclusively, to the designs from the . Figures 10 , 11 , 15 and 16 but can be used, for example, for all embodiments shown or described in the present application.

[0080] In Figure 9The first ring 9a has a V-shaped groove extending along its circumference. A counterpart formed by the second ring is arranged in the groove, adapted to this groove shape, and connected, in particular vulcanized or glued, to the first ring 9a in the groove.

[0081] In Figure 10 The first ring 9a also has a V-shaped groove extending over the circumference of the first ring 9a, and the second ring 9b is an O-ring with a circular cross-section. The second ring 9b is also arranged in the V-shaped groove and is connected therein, in particular, by a material fit to the first ring 9a. In the embodiment of Figure 11 the first ring 9a has a flat surface facing the second ring 9b, on which the O-ring-shaped second ring 9b rests and to which the second ring 9b is firmly fastened.

[0082] Figure 15shows a first ring 9a, which has a step extending around its annular circumference, in which the second ring 9b, designed as an O-ring, is received. The second ring 9b is integrally connected to the first ring 9a. Optionally, the second ring 9b is loosely inserted into the first ring 9a, in particular into the stepped shoulder.

[0083] The front end of the seal, which is opposite the front end formed by the second ring 9b, has at least one groove extending around the annular circumference of the first ring 9a. The groove is enclosed by a first circumferential, in particular inner, groove wall 9c and a second circumferential, in particular outer, groove wall 9d.

[0084] The first groove wall 9c is continuous around its circumference and rests against its sealing surface, sealing the first pressure chamber 23b from the second pressure chamber 23c. The second groove wall 9d is provided with several recesses along its circumference, which make the second groove wall 9d permeable to fluid, thus sealing only the first groove wall 9c. The second groove wall 9d serves to support the seal against the sealing surface, preventing the seal 9 from tilting.

[0085] Alternatively, the second groove wall 9d can be continuous over the circumference, and the first groove wall 9c can be provided with the plurality of recesses, whereby the above description can be applied analogously to this embodiment. Thus, the second groove wall 9d can serve primarily for sealing, and the first groove wall 9c can serve primarily for support.

[0086] Figure 16shows a seal 9 which consists of only one ring, such as the material for the above-mentioned first ring 9a or the above-mentioned second ring 9b, depending on the expected pressure difference between the first pressure chamber 23b and the second pressure chamber 23c. One end of the seal is designed with a sealing lip which has an inclined inner surface which is inclined such that an internal pressure in the second pressure chamber 23c exerts a force on the sealing lip which presses at least with a force component against the sealing surface of the second housing part 3 or the end wall 20c. A plurality of recesses are arranged on the inner circumference, which extend, for example, along the height of the seal 5 or in the direction of the axis of rotation D and which, for example,are open towards the inner circumference to ensure that the sealing lip, even if it is deformed in the assembled state of the pump insert 1 in the receiving housing 20, is subjected to pressure fluid from the second pressure chamber 23c in order to press it against its sealing surface, which is formed, for example, by the second housing part 3. The end face of the seal 9 opposite the sealing lip can be flat or even or as in . Figure 15 be designed.

[0087] Figure 12 shows an annular seal 9, which has a first ring 9a made of the above-mentioned first material, alternatively of metal, in particular steel, which is substantially completely coated or overmolded over its surface with plastic, in particular the elastomeric or rubber-elastic or thermoplastic material, whereby a second ring 9b is formed.

[0088] Figure 13shows an annular seal 9, which has a first ring 9a, designed as an annular circumferential tube. The ring 9a can, for example, be made of a metallic spring material, in particular spring steel, as an alternative to the materials mentioned for the first ring 9a. The annular circumferential tube 9a can have a closed wall or, for example, be wound from a helical spring.

[0089] The first ring 9a is coated or overmolded over its outer circumference with plastic, in particular the elastomeric or rubber-elastic or thermoplastic material, whereby a second ring 9b is formed, which surrounds the first ring 9a. The tube 9a made of Figure 13 can thus act as a spring and the coating or overmolding 9b as a seal 9. The same applies analogously to the version made of Figure 14 .

[0090] The execution from Figure 14shows a first ring 9a, which is formed from a slotted tube or a C-shaped profile that extends in a closed ring. The slot of the C-shaped profile or the slotted tube 9a faces the interior and thus the second pressure chamber. The outer circumference of the first ring 9a is coated or overmolded with plastic, in particular an elastomeric, rubber-elastic, or thermoplastic material, resulting in a second ring 9b that at least partially surrounds the first ring 9a.

[0091] In the Figure 19 an embodiment of a spring 5 is shown, which is combined with a seal 9 and in the Figures 17 and 18 shown in conjunction with the pump insert 1.

[0092] The spring 5 from Figure 19has an annular spring structure 5b with a first spring structure ring 5k, which extends in particular concentrically around the axis of rotation D. The spring structure 5b is made of metal, in particular steel, which gives the spring 5 its essential spring property in the direction of the axis of rotation D. The annular spring structure 5b has a plurality of arms 5d projecting inward from the first spring structure ring 5k and distributed over its circumference, the inwardly projecting ends of which protrude freely. The arms 5c each have a contact surface 5d with which they rest against the end wall 20c. The underside of the first spring structure ring 5k of the spring structure 5b rests against the second housing part 3 in the area that is arranged in axial alignment with the cam ring 12 in the direction of the axis of rotation D. The first spring structure ring 5k has two fastening elements 5a, which are formed as continuous recesses, such as bores or elongated holes.The bore or elongated hole is surrounded at least over part of its circumference by a wall which has a thickness extending along or in the direction of the rotation axis D and which is smaller than the groove width of the annular groove 6a of the positioning element 6. As a result, a part of this wall can snap into the annular groove 6a, whereby the spring 5 is captively fastened to the at least one positioning element 6. For example, to insert the positioning elements 6 into the through-holes of the fastening elements 5a, the spring structure ring 5k can be elastically compressed or pressed apart along an imaginary connecting line between the two fastening elements 5a in order to enable it to be plugged onto the positioning elements 6 and, when released, to enable part of the wall to snap into the annular groove 6a.

[0093] The spring structure 5b has a second spring structure ring 5j, which surrounds the second pressure chamber 23c in a ring shape. Furthermore, the spring structure 5b has a third spring structure ring 5i, which extends around the axis of rotation D and is arranged within the first spring structure ring 5k, from which the arms 5d protrude. At least the second spring structure ring 5j, preferably and if present also the third spring structure ring 5i and optionally also the first spring structure ring 5k are coated or overmolded with plastic, in particular the elastomeric or rubber-elastic or thermoplastic material, at least partially or completely, so that at least the ends of the second ring, which comprises the second spring structure ring 5j, and of the third ring, which comprises the third spring structure ring 5i, pointing in the direction of the axis of rotation D are formed with a surface made of plastic, in particular the elastomeric or rubber-elastic or thermoplastic material.Furthermore, the elastomeric, rubber-elastic, or thermoplastic material separates the second pressure chamber 23c from the first pressure chamber 23b. The second ring with its overmolding or coating can thus be defined as a seal 9. The third ring with its coating or overmolding seals the bore of the second housing part 3, in which a portion of the pump shaft 10 is arranged, from the first pressure chamber 23b and the second pressure chamber 23c. The overmolding or coating of the third ring is supported on the second housing part 3 and, opposite, on the housing wall 20c. List of reference symbols

[0094] 1Pump insert 2First housing part 2aRecess, such as blind bore 2First inlet channel 2cSecond inlet channel 3Second housing part 3aRecess, such as through-hole 3First outlet channel 3cSecond outlet channel 4Rotor 5Spring 5aFastening element 5bSpring structure 5cArm 5dContact surface 5ePositioning element 5fTubular section 5gFlat section 5hSlotted tubular section 5idird ... 6Positioning element / pin 6aRecess, such as annular groove 7First seal / sealing ring 8Second seal / sealing ring 9Sealing element / seal / sealing ring / axial seal 9aFirst ring 9bSecond ring 9cFirst groove wall 9dSecond groove wall 10Pump shaft 11Shaft seal 12Third housing part / cam ring 12aRecess 13 wings 20Receiving housing, such as housing pot 20cEnd wall 20dPeripheral wall 20eOpening 21Gear, such as a sprocket 23First pressure chamber 23Second pressure chamber 24Suction chamber 25Receiving chamber 26Pump chamber 27First delivery chamber 28Second delivery chamber 29Delivery cell 30Shaft-hub connection DRotation axis

Claims

1. A pump, comprising: an accommodating housing (20) which forms a cup-shaped accommodating space (25) comprising an end-facing wall (20c) and a circumferential wall (20d); and a pump insert (1) which is inserted into the accommodating space (25) as a unit which can be handled separately from the accommodating housing (20) via an opening in the accommodating housing (20) which lies opposite the end-facing wall (20c), wherein the pump insert (1) comprises: - a rotor (4) and a pump shaft (10); - a first housing part (2) and a second housing part (3), between which the rotor (4) is arranged such that it can be rotated about a rotational axis (R) and relative to the first and second housing part (2, 3), wherein the pump shaft (10) is non-rotationally connected to the rotor (4) and mounted such that it can be rotated in the first housing part (2) and in a blind cavity of the second housing part (3); and - a stroke ring (12) which surrounds the rotor (4) and is arranged between the first housing part (2) and the second housing part (3), wherein a first delivery chamber (27) which is connected to a first pressure space (23b) via a first outlet channel of the second housing part (3), and a second delivery chamber (28) which is connected to a second pressure space (23c) via a second outlet channel of the second housing part (3), are formed radially between the stroke ring (12) and the rotor (4), and a second seal (8), in particular a sealing ring, which is arranged between the accommodating housing (20) and the second housing part (3) seals off the first pressure space (23b), which is formed between the end-facing wall (20c) and the second housing part (3), in relation to a suction space (24) which is formed between the circumferential wall (20d) and the stroke ring (12), and a first seal (7) which is arranged between the first housing part (2) and the accommodating housing (20), in particular the circumferential wall (20d) of the accommodating housing (20), for example seals off the suction space (24) with respect to the outside or with respect to the opening in the accommodating housing (20), wherein the suction space (24) is formed between the first seal (7) and the second seal (8), and a sealing element (9) which is arranged between the second housing part (3) and the end-facing wall (20c) of the accommodating housing (20) annularly surrounds the second pressure space (23c).

2. The pump according to the preceding claim, characterised in that the pump is embodied as a twin-stroke pump.

3. The pump according to any one of the preceding claims, characterised in that the pump insert (1) comprises a first inlet channel (2b) for the first delivery chamber (27) and a second inlet channel (2c) for the second delivery chamber (28), wherein the first and second inlet channels (2b, 2c) port into the suction space (24).

4. The pump according to any one of the preceding claims, characterised in that the pump is embodied for supplying different consumers and / or for different pressure levels between the first outlet channel (3b) and the second outlet channel (3c).

5. The pump according to any one of the preceding claims, characterised in that the pump is a vane cell pump and / or in that the rotor (4) comprises slot-shaped guides in which delivery elements (13) are accommodated such that they can be shifted radially with respect to the rotational axis (R).

6. The pump according to the preceding claim, characterised in that the delivery elements (13) and / or the rotor (4) respectively form a sealing gap with the first housing part (2) and the second housing part (3).

7. The pump according to any one of the preceding two claims, characterised in that the first housing part (2), the second housing part (3) and the stroke ring (12) enclose and delineate a pump chamber (26) in which the rotor (4) and the delivery elements (13) are arranged.

8. The pump according to any one of the preceding claims, characterised by at least one positioning element (6) which positions the second housing part (3) with respect to its angular position about the rotational axis (R) relative to the first housing part (2), wherein the at least one positioning element (6) comprise a cavity, in particular an annular groove or a clearance groove, with which a disc-shaped or annular securing element engages which prevents the second housing part (3) from being axially removed from the at least one positioning element (6).

9. The pump according to the preceding claim, characterised in that the at least one positioning element (6) is formed as a part which is separate from and anchored in the first housing part (2), wherein the end of the at least one positioning element (6) which lies opposite the end anchored in the first housing part (2) preferably protrudes out of the second housing part (3).

10. The pump according to any one of the preceding two claims, characterised in that the at least one positioning element (6) extends through a cavity in the second housing part (3), in particular a transit bore, one of which is provided for each positioning element (6), and / or through a cavity in the stroke ring (12), in particular a bore or transit bore.

11. The pump according to any one of the preceding three claims, characterised by a spring (5) which is captively fastened to the pump insert (1) and / or the at least one positioning element (6), wherein the spring (5) is preferably connected to the at least one positioning element (6) in a positive fit, such that the spring (5) is fastened to the at least one positioning element (6).

12. The pump according to any one of the preceding claims, characterised in that the pump insert (1) is prevented from falling out of the accommodating housing (20) by a screw which serves as an axial securing element, wherein the screw abuts the first housing part (2) and / or holds the first housing part (2) on the accommodating housing (20), secured against shifting along or in the direction of the rotational axis (R).

13. The pump according to any one of the preceding claims, characterised in that the pump is configured for supplying an automatic transmission of a motor vehicle, and the accommodating housing (20) is formed by a transmission housing.

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