EP3081744B1 - Pump - Google Patents

Description

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. 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. The invention relates to the design or attachment of a spring of the pump.

From the WO 2013/185751 A1 a so-called cartridge pump is known which has a pump assembly which essentially consists of a rotor, a stroke 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 pointing away from the rotor. The pump assembly can be inserted into a cup-shaped housing, the spring element being supported on the bottom of the cup-shaped housing. The housing is closed by a housing cover that holds the pump unit in its installed position. The rotor has an internal structure for a shaft-hub connection with a pump shaft.

the U.S. 3,207,077 discloses a fluid pump having a rotor enclosed between a ring and two pressure plates, the ring and the pressure plates being positioned relative to one another by means of pins. On each of the pins there is a coil spring that is supported on the one hand on one of the pressure plates and on the other hand on a housing cover, whereby the pressure plate is pressed against the ring.

In the EP 2 754 896 A1 Several possibilities are described how a housing cover that closes a pump chamber in which a rotor is located can be pressed by a spring with a spring force against the housing part surrounding the pump chamber. In one embodiment, a leaf spring is fastened to the face of the pump with two screws, a main section of the spring located between the screws pressing against the housing cover. In another embodiment, a plurality of leaf springs are provided, each of which is fastened to the end face of the pump by means of a screw, each leaf spring having a section which presses against the housing cover. In yet another embodiment, the housing cover itself forms a plurality of resilient arms, the free ends of which are each fastened to the housing part on the front side with a screw. In yet another embodiment, several screws attached to the housing part are provided on the front of the pump, the screw shafts of which are each surrounded by a helical spring that is indirectly supported on the one hand on the screw head and on the other hand on the housing cover.

the DE 10 2013 209 877 A1 shows a pendulum vane pump, which essentially has a shaft, an inner rotor, a pendulum and an outer rotor which is surrounded by a housing. The outer rotor is connected to the inner rotor via a pendulum, which in turn is connected to the shaft in a rotationally fixed manner and is driven by it. The housing surrounding the outer rotor is closed on the front side by a pressure plate pierced by the shaft. The shaft is secured by means of a securing element on the side of the pressure plate facing away from the outer rotor. Between the securing element and the pressure plate there is a spring element which presses the pressure plate in the axial direction against the housing surrounding the outer rotor. For this purpose, the spring element is supported on the securing element.

The invention is based on the object of specifying a space-saving pump that can be produced inexpensively.

The object is achieved with the features of claim 1. Advantageous further developments result from the dependent claims, the description and the figures.

The invention is based on a pump, in particular a positive displacement pump, such as a vane or rotary vane pump. The pump comprises a housing which encloses a pump space. A rotor is arranged in the pump chamber so that it can rotate 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 such that it can rotate about an axis of rotation relative to the first and second housing parts. The rotor can be directly or indirectly connected to a pump shaft to transmit torque or be connectable, 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, in which conveying elements, such as, for example, vanes, slides or rollers, can be moved, in particular displaced, radially to the axis of rotation. The conveying elements are received or supported by the rotor in such a way that they rotate with the rotor about its axis of rotation.

The pump shaft can extend through the housing and be mounted on the housing so as to be rotatable 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 outer 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 non-rotatably by means of a straight-toothed shaft-hub connection. The shaft-hub connection has an internal toothing with several teeth and an external toothing engaging in the internal toothing with several teeth.

A third housing part, in particular a cam ring, which surrounds the rotor over its circumference, can be arranged between the first housing part and the second housing part. The ring-shaped third housing part can be a separate part from the first and second housing parts. Alternatively, the third housing part 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 conveying elements, for example in an annular manner.

The first housing part, the second housing part and the third housing part enclose and delimit a pump chamber in which the rotor and the conveying elements are arranged. At least one delivery chamber is formed radially between the third housing part and the rotor, which is rotatably enclosed between the first and second housing parts.

Between adjacent conveying elements, a conveying cell is formed which is delimited on the circumferential side by an inner circumferential surface of the third housing part and along the axis of rotation by the first housing part on one side and by the second housing part on the other side, and the volume of which changes depending on the rotational position of the rotor changed around its axis of rotation. The pump has a multiplicity of delivery elements and thus, in particular, an identical multiplicity of delivery cells which are formed between the delivery elements.

The inner circumference of the third housing part has a contour along which the conveying elements slide when the rotor rotates. The contour is designed, in particular, in such a way that the volumes of the conveyor cells moving through the conveyor chamber due to the rotation of the rotor initially increase and then decrease. With one complete revolution of the rotor, the conveying elements are moved away from the axis of rotation and towards the axis of rotation at least once. The pump can, for example, have a double stroke, i.e. H. with a first conveying chamber and a second conveying chamber, which are traversed once by the conveying elements or the conveying cells in a full revolution. This means that the conveyor elements are alternately moved twice away from the axis of rotation and twice toward the axis of rotation during a complete revolution. During a rotation of the rotor, there is initially an increase in volume of a delivery cell and then a volume reduction of this delivery cell.

The pump can have a first channel which opens into the area of the delivery chamber in which the volume increase takes place and a second channel which opens into the area of the delivery chamber in which the volume reduction of this delivery cell takes place. By increasing the volume of the delivery cell, the first channel acts as a suction channel. Due to the reduction in volume, the second channel acts as a pressure channel. A multi-stroke pump can have several suction channels and several pressure channels. In the case of a double-stroke pump, two pressure channels and two suction channels can be provided. A first suction channel can open into the first delivery chamber and a second suction channel can open into the second delivery chamber. A first pressure channel can open into the first delivery chamber and a second pressure channel can open into the second delivery chamber. With the one about the first The fluid conveyed to the conveying chamber can, for example, be supplied with consumers other than or the same as with the fluid conveyed via the second conveying chamber. When supplying different consumers, different pressure levels can arise between the first pressure channel and the second pressure channel. The conveying elements and / or the rotor each form a sealing gap with the first housing part and the second housing part. The at least one suction channel can be connected to a fluid storage container, such as for example an oil container, in particular be in fluid connection. The at least one pressure channel can be connected to at least one fluid consumer, such as being in fluid connection with a transmission.

The pump has at least one positioning element which positions the second housing part with respect to its angular position about the axis of rotation relative to the first housing part. The at least one positioning element can be formed by the first housing part, in particular formed in one piece or monolithically. Alternatively, the at least one positioning element can be formed as a part which is separate from the first housing part and which is anchored in the first housing part. For example, the positioning element can be screwed or pressed into the first housing part, i. H. be positively and / or non-positively anchored. Alternatively or additionally, the at least one positioning element can be firmly anchored in the first housing part, such as glued, soldered or welded, for example. 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.

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.

The second housing part and in particular also the third housing part are mounted on the at least one positioning element, secured against rotation about the axis of rotation. The at least one positioning element can extend through a recess of the second housing part provided for each positioning element, for example through a bore or through bore. The at least one positioning element can, for example, by a Extending recess of the third housing part z. B. can be designed as a bore, elongated hole or the like.

In particular, the end of the at least one positioning element, which is opposite the end anchored in the first housing part, protrudes from the second housing part, in particular from the end face of the second housing part which is opposite the end face facing the rotor or which faces an end wall of a receiving housing shows.

The pump includes a spring, such as a plate spring. The second housing part is arranged between the spring and the rotor. The spring is supported on the second housing part and, for example, on a receiving housing, in particular an end wall of the receiving housing. The receiving housing can be cup-shaped, for example. The receiving housing can have a circumferential wall extending around the axis of rotation of the rotor and an end wall arranged at the end of the circumferential wall, the second housing part being surrounded over its circumference by the circumferential wall and the spring, such as a main section of the spring, being supported on the end wall . The spring tends to push the second housing part away from the end wall of the receiving housing.

The spring is attached to the at least one positioning element. The spring can, for example, be positively, in particular snapped, or non-positively connected to the positioning element, so that the spring is held on the at least one positioning element and is supported or can be supported on the second housing part. It is preferred that the spring is secured against rotation about the axis of rotation, in particular positively and / or non-positively, to which at least one positioning element is attached. In addition, the spring can be attached to the second housing part, for example in a form-fitting manner. The spring has a main section which can spring towards the first housing part and away from the first housing part along the axis of rotation. In the relaxed state of the spring, there is a spring gap between the second housing part and the main section of the spring, so that the main section of the spring can be moved towards the second housing part while the spring is simultaneously tensioned. The spring has support portions which are connected to the main section, with the spring gap between the second housing part and the main section. The support sections are supported flat on the second housing part, for example. The main section is particularly intended to be attached to the end wall of the receiving housing, in particular on a z. B. annular projection of the end wall, z. B. support flat.

At least a part of the main section can be arranged between the axis of rotation and the at least one support section. This has the effect that the main section is offset closer to the axis of rotation than the at least one support section. For example, the main section can be ring-shaped, with several support sections protruding from the main section, in particular one per positioning element. The main section is arranged offset with respect to the at least one support section along the axis of rotation. As a result, the spring can be supported on the one hand on the second housing part and on the other hand can spring towards the second housing part.

The main section of the spring can have a recess, in particular a circular opening, for example, through which the pump shaft and / or a structure of the second housing part that forms the pump shaft bearing extends. The structure forming the pump shaft bearing can be a ring structure formed on the second housing part, which protrudes from the second housing part towards the end wall of the receiving housing. As a result, a large contact surface can be formed for the pump shaft and the thickness of the second housing part can otherwise remain small.

The spring can have or form at least one fastening element, in particular on or in the area of one of the support sections. For example, the at least one fastening element can serve as a support section or one fastening element can be provided for each support section. By means of the fastening element, the spring can be fastened or fastened to the at least one positioning element or the second housing part. The fastening element, which is designed, for example, for a positive connection with the fastening element, can be snapped onto the at least one positioning element.

The at least one positioning element can have a recess, such as an annular groove over 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 locking disk or a circlip, similar to locking washers for shafts according to DIN 6799 or locking rings for shafts according to DIN 471, in particular with the difference that they are formed by the spring, namely can be molded onto the support sections.

In alternative embodiments, the securing element, in particular the securing washer designed for example according to DIN 6799 or the circlip designed according to DIN 471, can actually be a washer or a ring, ie. H. not be formed on the spring and, for example, only serve to ensure that the second housing part cannot be pulled axially from the positioning element. In this embodiment, the spring can be fastened to the second housing part or the securing element or be framed between the securing element and the second housing part, wherein the fastening element of the spring can be pushed onto the positioning element. In alternative embodiments, the positioning element can be designed with a head, for example, the second housing part being framed between the first housing part and the head, so that the second housing part is prevented from being pulled off the first housing part or the positioning element. In these embodiments, the spring can be fastened to the second housing part or to the head, or it can be framed between the head and the second housing part, wherein the fastening element of the spring can be pushed onto the positioning element.

In further embodiments, the recess can be an annular groove which extends over the circumference of the cylindrical or pin-shaped positioning element and which has a width which extends along the longitudinal axis of the positioning element and which is dimensioned such that the fastening element of the spring with play along the longitudinal axis in the annular groove is recorded. This makes it possible to ensure that the support sections or the fastening section of the tongue are supported on the second housing part and not on a groove flank of the annular groove.

The pump can have a pump shaft which is connected non-rotatably to the rotor and is rotatable about the axis of rotation. The pump shaft can be rotatably mounted at least in the first housing part. In addition, the pump shaft can be rotatably mounted in the second housing part, in particular in a sack-shaped recess or in a continuous recess, in particular a bore, through the second housing part. The sack-shaped recess has the advantage that the pump chamber is sealed off from the end face of the second housing part pointing away from the pump chamber. The continuous recess has the advantage that it is easier to manufacture and ensures greater stability. The bearing or bearings can be plain bearings or roller bearings.

The pump shaft has a structure, in particular external toothing, for a shaft-hub connection with the rotor. The diameter of the structure can be greater 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 the axis of rotation. This has the effect that the shaft cannot be pulled out of the fully assembled pump assembly.

In particular, the first housing part, the second housing part, the third housing part, the rotor, the conveying elements, the positioning elements, the spring and the pump shaft essentially form a pump assembly that can be handled as a unit. The fact that the spring is fastened to the at least one positioning element can prevent the assembly from falling apart. The fastening sections of the spring or the securing elements separate from the spring effect an axial shaft securing so that the pump assembly does not fall apart.

Due to the simple handling of the pump assembly, it can be received in the receiving housing, which can be formed, for example, by a transmission housing for a motor vehicle, or inserted into the receiving housing, for example via an opening in the receiving housing opposite the end wall.

A cover or an axial securing element prevents the pump or the pump assembly from falling out of the receiving housing, whereby the spring tensioned during insertion presses the pump assembly, in particular the first housing part, against the axial securing element, the axial securing element preventing the spring from being relaxed . The axial securing element can, for example, be ring-shaped and inserted in an annular groove which is formed on the preferably cylindrical inner circumference of the receiving housing. The axial securing element can be formed by a cover which at least partially or completely closes the opening.

In further embodiments, a seal can be arranged between the second housing part and the receiving housing, in particular the peripheral wall, which has a first space that is formed between the end wall and the second housing part, in relation to a second space that is between the peripheral wall and the first and / or third housing part is formed, seal. For example, the first space can be connected to the pump chamber in which the rotor is arranged by means of the first channel. For example, the second space can be connected to the pump chamber by means of the second channel. In particular, the first space can be arranged on the suction side and the second space on the pressure side or the second space on the suction side and the first space on the pressure side. Accordingly, the pressure space can be formed between the end wall and the second housing part, wherein the suction space can be formed between the peripheral wall and the first / and / or third housing part. The suction chamber can be connected to the at least one delivery chamber with the at least one suction channel. The pressure chamber can be connected to the at least one delivery chamber with the at least one pressure channel.

An additional seal can be arranged between the first housing part and the receiving housing, in particular the peripheral wall, the second space being arranged between the first and second seals. The second seal can effect the sealing of the second space to the outside or to the opening of the receiving housing.

If the first space is arranged on the suction side of the pump chamber and the second space on the pressure side, the axial securing element is only slightly loaded with an axial force during the pumping operation. However, the spring force must then be selected to be at least so strong that parts of the pump assembly are compressed at least so strongly along the axis of rotation that the pump chamber is sufficiently sealed.

If the first space is on the pressure side and the second space is on the suction side, the second housing part acts like a piston, which increases the force along the axis of rotation on the axial securing element when the pressure increases and thus also presses the parts of the pump assembly together to form a seal, with an increasing force increasing delivery pressure.

The spring can be formed from metal such as spring steel. As an alternative or in addition, the spring can have a plastic, such as, for example, an elastomer or polymer material. The spring can be formed, for example, from an elastomer or polymer material or from a metal spring that is partially or completely coated with the plastic, such as, for example, overmolded. This has the advantage that the spring can also fulfill a double function as a seal. For example, the end wall can have a projection or a sealing seat on which the spring is supported in a sealing manner, in particular with the surface of the spring formed from the plastic. The second housing part can have a sealing seat on which the spring, in particular with the surface formed from the plastic, is sealingly supported.

The spring designed as a seal can, for example, seal a first part of the pressure chamber into which the first outlet channel opens from a second part of the pressure chamber into which the second outlet channel opens. This allows a pump with two pressure levels to be provided.

The spring designed as a seal can, for example, seal the pressure chamber into which the first and possibly the second outlet channel open from the suction chamber into which the first and possibly the second inlet channel open.

Figur 1

eine Pumpenbaugruppe,

Figur 2

die Pumpenbaugruppe aus Figur 1 eingesetzt in ein Aufnahmegehäuse,

Figur 3

eine perspektivische Ansicht der Pumpenbaugruppe aus Figur 1,

Figur 4

die Feder der Pumpenbaugruppe aus Figur 3,

Figur 5

eine alternative Ausführung einer Feder,

Figur 6

eine alternative Ausführung einer Feder,

Figur 7

eine alternative Ausführung einer Feder,

Figur 8

eine alternative Ausführung einer Feder,

Figur 9

eine alternative Ausführung einer Feder und

Figur 10

eine alternative Ausführung einer Feder,

Figur 11

eine Querschnittsansicht durch die Pumpenbaugruppe aus den Figuren 1 bis 3.

The invention has been described on the basis of several examples and embodiments. Particularly preferred embodiments of the invention are described with reference to figures. Show it:

Figure 1

a pump assembly,

Figure 2

the pump assembly Figure 1 inserted in a housing,

Figure 3

FIG. 3 is a perspective view of the pump assembly Figure 1 ,

Figure 4

the spring of the pump assembly Figure 3 ,

Figure 5

an alternative design of a spring,

Figure 6

an alternative design of a spring,

Figure 7

an alternative design of a spring,

Figure 8

an alternative design of a spring,

Figure 9

an alternative embodiment of a spring and

Figure 10

an alternative design of a spring,

Figure 11

a cross-sectional view through the pump assembly of FIGS Figures 1 to 3 .

the Figure 1 FIG. 13 shows a pump assembly that is housed in a receptacle housing 20 as in FIG Figure 2 shown, can be used. The pump assembly comprises a spring 5 designed, for example, as a plate spring, which is inserted into the Figures 4 to 10 shown in various embodiments.

Turn off the pump or pump assembly Figure 1 has a rotor 4 which is connected non-rotatably to a pump shaft 10 of the pump 1 via a shaft-hub connection 30. The rotor 4 has, in particular, slot-shaped recesses that serve as guides. A conveying element 13, in particular a wing, is assigned to each recess. The blade 13 is in its recess radially or away from the axis of rotation of the rotor 4 and displaceable towards the axis of rotation of the rotor 4, in particular guided with a single translational degree of freedom, displaceable back and forth, as best shown Figure 11 is recognizable. The blades 13 are rotated with the rotor 4. The pump 1 has an annular housing part 12, which is referred to as the third housing part 12 for better identification can be. The third housing part 12 can be designed as a cam ring. The third housing part 12 is enclosed between a first housing part 2 and a second housing part 3 and is non-rotatable 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 third housing part 12 and is axially limited by the second and third housing part 2, 3, can also be referred to as a pump chamber 26. The rotor 4 and the vanes 13 are arranged in the pump chamber 26.

As on the best Figure 11 As can be seen, at least one delivery chamber 27, 28 is formed radially between the rotor 4 and the third housing part 12. The embodiment shown here comprises two delivery chambers, namely a first delivery chamber 27 and a second delivery chamber 28.

A delivery cell 29 is formed between adjacent blades 13, the volume of which changes as a function of the rotational position of the rotor 4 about its axis of rotation. Since the pump has several vanes 13, it also has several delivery cells 29 accordingly. In each of the conveying chambers 27, 28 there are several conveying cells.

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.

The third housing part 12, in particular the cam ring, and / or the vanes 13 can be magnetized so that the vanes 13 rest against the inner circumferential surface of the third housing part 12 due to magnetic force, especially when the rotor 4 is not rotating. This allows an early pressure build-up when starting or cold starting, ie when the pump shaft 10 begins to rotate. Alternatively or additionally, due to the centrifugal force when the rotor 4 rotates, the blades 13 can be pressed outwards, ie away from the axis of rotation of the rotor 4, against the inner circumferential surface of the third housing part 12. The wings 13 or each of the wings 13 forms a third sealing gap with the inner circumferential surface of the third housing part 12.

The inner circumferential surface of the third housing part 12 has a contour that causes the vanes 13 to extend at least once (increase in volume of delivery cell 29) and retract once (decrease in volume of delivery cell 29) during a full revolution of rotor 4. The pump 1 shown in the example is double-stroke, i. H. with two delivery chambers 27, 28, whereby the wings 13 extend once and retract once per delivery chamber 27, 28 when they are moved through the delivery chamber 27, 28 by rotating the rotor 4. This has the effect that the blades 13 extend, retract, extend and retract again during one full revolution of the rotor 4, or in other words, extend twice and retract twice. A conveyor cell 29 is formed between adjacent vanes 13, the volume of which is increased or decreased by the extension and retraction of the vanes 13 delimiting this conveyor cell 29, namely depending on the contour of the inner circumferential surface of the third housing part 12.

How best to look Figure 3 As can be seen, the pump 1 has an opening or a channel 3b which opens into the area of the delivery chamber 27, 28 in which the volume of the delivery cells 29 decreases during the rotation of the rotor 4. This has the effect that fluid located in the delivery cells, such as oil, for example, is displaced through the channel 3b, which here serves as an outlet.

The pump 1 has an opening or a channel 2b which opens into the area of the delivery chamber 27, 28 in which the volume of the delivery cells 29 increases during the rotation of the rotor 4. This has the effect that fluid is conveyed or sucked through the channel 2b into the enlarging delivery cell 29. Since the pump 1 is two-stroke in this example, it has two inlet channels 2b and two outlet channels 3b, the first inlet channel 2b and the first outlet channel 3b into the first delivery chamber 27 and the second inlet channel 2b and the second outlet channel 3b into the second delivery chamber flow out. A reverse configuration of the inlet and outlet channels 2b, 3b is also conceivable. This means that channel 2b can be the outlet channel and channel 3b can be the inlet channel.

When the rotor 4 rotates, fluid, in particular liquid, is sucked through the channel 2b into the enlarged delivery cells 29 and transported into the area in which the channel is located 3b opens, the fluid being discharged from the delivery cells 29, which then decrease in size, via the channel 3b.

The pump 1 comprises at least one positioning element 6, in the example shown two positioning 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.

The pin-shaped positioning element 6 positions the second housing part 3 and the third housing part 12 with regard to their angular positions about the axis of rotation relative to the first housing part 2. The second housing part 3 and the third housing part 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 third housing part 12 has a recess for this purpose. The second housing part 3 has a through hole through which the positioning element 6 extends. The positioning element 6 protrudes with its pin-shaped second end over the end face which faces away from the pump chamber 26. This protruding section of the positioning element 6 has a recess, such as an annular groove 6 a, or at least a part thereof, which extends over the circumference of the positioning element 6. In the recess 6a a securing element or fastening element 5a is arranged, which is fastened in particular non-positively and / or positively 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 third housing part 12 from falling apart axially, or in other words the second and third housing part 3, 12 from being pulled off the positioning element.

The spring 5 can be designed, for example, as a plate spring, as a star disk or with the geometries of a star disk. The spring has a main section 5c which is connected to the fastening element 5a via an arm. In the example shown, the (plate) spring 5 has two fastening elements 5a, which are each connected to the main section 5c via an arm 5b. The fastening element 5a prevents on the one hand that the housing parts 2, 3, 12 detach from each other, and on the other hand enables the spring 5 to be fastened to the pump unit or to the positioning element 6. The main section 5c of the spring 5 is offset along the axis of rotation of the rotor 4 or the pump shaft 10 relative to the fastening element 5a or arranged to a support section 5d. The fastening section 5a and / or the support section 5d facing the second housing part 3 rest on the second housing part 3 or are supported thereon. The fastening section and / or the support section 5d bear as flat as possible on at least one correspondingly formed, preferably flat surface of the second housing part 3. The main section 5c, on the other hand, is spaced apart from the second housing part 3 by a gap or spring gap. The main section 5c can thus spring towards the second housing part 3, whereby the spring 5 is tensioned, and can spring away from the second housing part 3, whereby the spring is relaxed. The main section can preferably bear as flat as possible on at least one surface or flat surface formed by an essentially annular shoulder of the end wall 20c. In particular, it is preferred that the spring 5 - taking into account the stiffness / stresses or the spring diagram (force-displacement characteristic) of the spring 5 - as flat as possible on the second housing part 3 and the receiving housing, in particular on the end wall or the at least one surface of the substantially annular shoulder.

The main section 5c of the spring 5 has an in particular circular opening 5e through which a section of the second housing part 3 extends. This enables a compact design to be achieved.

The spring 5 can comprise or be a spring made of metal, which can optionally be coated, encapsulated or provided with injected geometries at least partially or completely with a plastic material, in particular an elastomer or a material whose main component is an elastomer. The spring 5 can take on an additional function as a seal due to the coating, overmolding or injection-molded geometries.

The pump shaft 10 is rotatably mounted on the first and second housing parts 2, 3, in particular by means of a sliding bearing in each case.

Between the section of the pump shaft 10, which is rotatably supported in the second housing part 3, and the section of the pump shaft 10 which is rotatably supported in the first housing part 2, an outer structure, such as an external toothing, is formed on the pump shaft 10, which is in positive engagement with a corresponding internal structure, in particular internal toothing of the rotor 4, in order to effect a shaft-hub connection 30. The outer diameter of the outer structure of the pump shaft 10 is greater 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 axially fixed between the first and second housing parts 2, 3, i.e. a displacement of the pump shaft 10 along the axis of rotation in both directions is essentially not possible. For this purpose, the inner diameter of the sections of the first housing part 2 and of 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.

On its end facing away from the pump chamber, the first housing part 2 has an annular pocket 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 from the outside.

The end of the pump shaft 10, which is opposite the end which is arranged in the area of the spring 5, has an outer structure for a shaft-hub connection with a gear wheel 21, in particular a chain wheel. The gear wheel 21 is seated in a rotationally fixed manner on the pump shaft 10. The gear wheel 21 can be driven by a chain, which in turn is driven by, for example, a crankshaft or another shaft that can be connected, for example, to an engine of the vehicle. For its attachment to the pump shaft 10, the gear wheel 21 has an internal thread with which it is screwed with an external thread of the pump shaft 10 against a shoulder of the pump shaft 10. An anti-rotation lock 22, which is seated on the shaft 10 in a non-rotating manner, secures the gear wheel 21 against unintentional loosening. The anti-rotation device 22 has an angled section which engages positively in the gear wheel 21, whereby a loosening of the gear wheel 21 is prevented.

The pump unit off Figure 1 is used in a, for example, cup-shaped receiving housing 20, such as a housing pot ( Figure 2 ). The receiving housing 20 has a circumferential wall 20d which forms the pump unit 1 Figure 1 surrounds the circumference. The receiving housing 20 also has an end wall 20c, which is connected to the peripheral wall 20d, the main portion 5c of the spring 5 being supported on the end wall 20c, in particular on an, for example, annular projection 20a of the end wall 20c.

The pump unit off Figure 1 is held between the end wall 20c and an axial locking element 9, in particular an axial locking ring, which is arranged in an annular groove 20b of the peripheral housing 20, so that the spring 5 is tensioned.

Between the end wall 20c and a second seal 8, which is arranged in an annular groove arranged on the outer circumference of the second housing part 3 and which forms a sealing gap with the circumferential wall 20d, a first space 23 (pressure space) is formed into which the pumped Fluid (liquid) is conveyed. The space 23 is in turn connected to a fluid consumer, such as a lubricant consumer, in particular a gear, by means of a channel (not shown). A second space 24 (suction space) is formed between the second seal 8 and a first seal 7, which is arranged in an annular groove arranged on the outer circumference of the first housing part 2 and which forms a sealing gap with the circumferential wall 20d, from which the fluid via the pump is funded in room 23. The space 24 can be connected to a storage container for the fluid, for example by means of a channel. When the fluid is conveyed, the pressure in the space 23 increases with increasing speed, whereby the second housing part 3, in addition to the pretensioning force of the spring 5, clamps the third housing part 12 firmly between the first and second housing parts 2, 3. As a result, the first, the second and the third housing part 2, 3, 12 are sealed off from one another. The connection between the axial securing element 9 and the first housing part 2 is so strong that it can withstand the axial force on the axial securing element 9 caused by the pressure in the space 23, ie it cannot be released. As an alternative to the axial securing element 9 formed as a spring ring, a housing cover can be fastened to the receiving housing 20 on which the first housing part 2 is axially supported. In the Figure 3 used spring 5 is in Figure 4 shown. The pen out Figure 8 resembles the feather from Figure 4 .

The fastening element 5a of the spring 5 from the Figures 4 and 8th has two legs which are arranged in the recess 6a. In these embodiments, the spring 5 can be fastened to the positioning elements 6 by rotating about the axis of rotation of the rotor 4 by means of its fastening elements 5a. The legs each have two guide surfaces 5g facing one another, which are arranged in relation to one another in such a way that the clear width formed between them increases towards the free end of the legs. The thickness of the legs is smaller than the clear width between the groove flanks of the recess 6a of the positioning element 6. The section of the reduced core diameter in the recess 6a, ie the diameter of the positioning element 6 measured at the groove base, is positively framed between the two legs of the fastening element 5a . During the fastening of the spring 5 to the positioning elements 6, the legs expand elastically slightly in that the sliding surfaces 5g facing one another slide on the section of reduced diameter of the recess 6a. In particular, the legs then snap into place with the section of reduced diameter. As a support, the legs can each have a concavely curved depression surface 5h. The recess surfaces 5h can preferably lie flat on the section of reduced diameter when the fastening element 5a is completely arranged in the recess 6a. This brings about a form-fitting safeguard against twisting of the spring 5 counter to the direction of rotation in which the spring 5 was rotated for fastening to the positioning elements 6. Between the legs, the fastening element 5a has a projection which has a stop surface which can rest against the section of reduced diameter of the positioning element 6 when the fastening element 5a is arranged completely in the recess 6a.

The ones in the Figures 5 and 6 shown fastening elements 5a are similar. The fastening element 5a is closed ring-shaped and has projections on its inner circumference 3 which enclose a diameter which is greater than the section of reduced diameter in the recess 6a and smaller than the outer diameter of the pin-shaped positioning element 6. The fastening element 5a Figure 5 points to his three Abrags facets or bevels on which the embodiment is made Figure 6 does not have. To fasten the spring 5, the fastening elements 5a are each pushed axially over a positioning element 6 until the three projections of the fastening element 5a snap into the recess 6a. It is also true here that the thickness of the fastening element 5a is smaller than the clear width between the groove flanks of the recess 6a.

Figure 7 shows a fastening element 5a which has a recess 5f towards the outside, ie pointing away from the axis of rotation. The spring 5 off Figure 7 can be attached to the positioning elements 6 by rotating about the axis of rotation. The two fastening elements 5a each have a single free end which, with respect to the arm 5b, is arranged further away than the recess 5f. The free end, in particular a sliding surface 5g of the free end pointing away from the axis of rotation, which slides during the fastening of the spring 5 to the positioning element 6, is more distant than the recess 5f with respect to the axis of rotation, in particular a recess surface 5h of the recess pointing away from the axis of rotation 5f, arranged. When fastening, this configuration has the effect that the free end is deflected by the positioning element 6 in that the sliding surface 5g slides on the positioning element 6 and the recess springs into the recess 6a. This results in a form-fitting connection. The thickness of the fastening element 6 is the same as in the other embodiments from FIGS Figures 4 to 10 also smaller than the clear width between the groove flanks of the recess 6a.

Figure 9 shows an embodiment with a closed ring-shaped fastening element 5a. The ring-shaped fastening element 5a forms a contour on its inner side of the ring with a first diameter section 5a ₁ and a second diameter section 5a ₂ , which are connected via a tapered section 5a ₃ . The first diameter section 5a ₁ has an inner diameter that is greater than the outer diameter of the positioning element 6. The second diameter section 5a ₂ has an inside diameter which is smaller than the outside diameter of the positioning element 6 and larger than the diameter of the positioning element 6 in the recess 6a. The clear dimension between the flanks of the tapered section 5a ₃ is smaller, in particular only slightly smaller than the diameter of the positioning element 6a in the recess 6a. To fasten the spring 5 to the at least one positioning element 6, the first Diameter section 5a _{1 of} the fastening element 5a pushed onto the positioning element 6. By turning the spring 5, the fastening element 5a with the second diameter section 5a _{2 is} pivoted into the recess 6a, whereby the tapering section at the section of reduced diameter in the recess 6a expands resiliently and contracts again when it has been moved past the section of reduced diameter .

The spring 5 off Figure 10 shows at least one fastening element 5a which is designed in the shape of a hook, a hook-shaped section extending _{around a receiving section 5a 4 by an amount greater than 180 °.} The receiving section 5a ₄ is followed by a tapering section 5a ₃ , the clearance of which is smaller than the diameter of the receiving section 5a ₄ . The diameter of the receiving section 5a ₄ is larger than the diameter of the positioning element 6 in the recess 6a and smaller than the outer diameter of the positioning element 6. The clear dimension between the flanks of the tapered section 5a ₃ is smaller, in particular slightly smaller than the diameter of the positioning element 6 in the recess 6a. By turning the spring 5, the tapered section 5a ₃ is first pivoted or moved past the section of reduced diameter in the recess 6a, whereby the tapered section 5a ₃ elastically expands somewhat and contracts again.

List of reference symbols

1

pump

2

first housing part

2a

Recess, such as a blind hole

2 B

Opening, such as an outlet or an inlet

3

second housing part

3a

Recess, such as a through hole

3b

Opening, such as inlet or outlet

4th

rotor

5

feather

5a

Fastener

5a1

first diameter section

5a2

second diameter section

5a3

Taper section

5a4

Receiving section

5b

poor

5c

Main section

5d

Support section

5e

opening

5f

deepening

5g

Sliding surface

5h

Recess area

6th

Positioning element / pin

6a

Recess, such as an annular groove

7th

first seal / sealing ring

8th

second seal / sealing ring

9

Axial locking element

10

Pump shaft

11

Shaft seal

12th

third housing part / stroke ring

12a

Recess

13th

wing

20th

Receiving housing, such as a housing pot

20a

Abragung

20b

Recess, such as an annular groove

20c

Front wall

20d

Perimeter wall

20e

opening

21

Gear, such as a sprocket

22nd

Anti-twist device

23

first room / pressure room

24

second room / suction room

25th

Spring gap

26th

Pump room

27

first pumping chamber

28

second delivery chamber

29

Delivery cell

30th

Shaft-hub connection

Claims (15)

1. A pump (1), comprising:

   - a rotor (4);

   - 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 and relative to the first and second housing parts (2, 3);

   - at least one positioning element (6) which positions the second housing part (3) with respect to its angular position about the rotational axis relative to the first housing part (2); and

   - a spring (5) which is fastened to the at least one positioning element (6), wherein the second housing part (3) is arranged between the spring (5) and the rotor (4),

   characterised in that

   - the spring (5) comprises a main portion (5c) and supporting portions (5d) connected to the main portion (5c), wherein a spring gap (25) exists between the second housing part (3) and the main portion (5c), and the supporting portions (5d) are supported on the second housing part (3).
2. The pump (1) according to the preceding claim, characterised in that the spring (5) is fastened, secured against rotating about the rotational axis, in particular in a positive fit.
3. The pump (1) according to any one of the preceding claims, characterised in that the at least one positioning element (6) is formed by the first housing part (2) or is anchored in the first housing part (2) as a part which is separate from the first housing part (2).
4. The pump (1) according to any one of the preceding claims, characterised in that a third housing part (12) which surrounds the rotor (4) over its circumference is arranged between the first housing part (2) and the second housing part (3), wherein the third housing part (12) is:

   - a part which is separate from the first and second housing parts (2, 3); or

   - a portion of the first housing part (2) which is formed by the first housing part (2); or

   - a portion of the second housing part (3) which is formed by the second housing part (3).
5. The pump (1) according to any one of the preceding claims, characterised in that the main portion (5c) can flex towards and away from the first housing part (2) along the rotational axis.
6. The pump (1) according to any one of the preceding claims, characterised in that at least some of the main portion (5c) is arranged between the rotational axis and the at least one supporting portion (5d).
7. The pump (1) according to any one of the preceding claims, characterised in that the spring (5) comprises or forms at least one fastening element (5a), by means of which the spring (5) is fastened to the at least one positioning element (6).
8. The pump (1) according to any one of the preceding claims, characterised in that the at least one positioning element (6) comprises a cavity (6a) with which the at least one fastening element (5a) of the spring (5) engages.
9. The pump (1) according to Claim 8, characterised in that the cavity (6a) is an annular groove which extends over the circumference of the cylindrical or pin-shaped positioning element (6) and exhibits a width, extending along the longitudinal axis of the positioning element (6), which is dimensioned such that the fastening element (5a) of the spring (5) is accommodated in the annular groove with a clearance along the longitudinal axis.
10. The pump (1) according to any one of the preceding claims, characterised in that the pump (1) comprises a pump shaft (10) which is non-rotationally connected to the rotor (4) and can be rotated about the rotational axis, wherein the pump shaft (10) is mounted such that it can be rotated in the first housing part (2) and in the second housing part (3).
11. The pump (1) according to Claim 10, characterised in that the spring (5) comprises a cavity (5e) through which the pump shaft (10) or the structure of the second housing part (3) which forms the pump shaft mounting extends.
12. The pump (1) according to any one of the preceding claims, characterised by an accommodating housing (20) which comprises a circumferential wall (20d), which extends around the rotational axis, and an end-facing wall (20c) which is arranged on the end-facing side of the circumferential wall (20d), wherein the second housing part (3) is surrounded over its circumference by the circumferential wall (20d), and the spring (5) - such as for example the main portion (5c) of the spring (5) - is supported on the end-facing wall (20c), in particular on an annular projection (20a) formed by the end-facing wall (20c).
13. The pump (1) according to Claim 12, characterised by an axial securing element (9) which is fastened to the accommodating housing (20), wherein the tensed spring (5) presses the pump assembly - comprising at least the first housing part (2), the second housing part (3), the rotor (4) and the pump shaft (10) - and in particular the first housing part (2) of the pump assembly against the axial securing element (9), wherein the axial securing element (9) prevents the spring (5) from being relaxed.
14. The pump (1) according to Claim 12 or 13, characterised in that a seal (8) which is arranged between the second housing part (3) and the accommodating housing (20) seals off a first space (23), which is formed between the end-facing wall (20c) and the second housing part (3), in relation to a second space (24) which is formed between the circumferential wall (20d) and the third housing part (12), wherein for example the first space (23) is connected to a pump chamber (26), in which the rotor (4) is arranged, by means of a channel (3b), and the second space (24) is connected to the pump chamber (26) by means of a channel (2b), and/or the first space (23) is arranged on the suction side and the second space (24) is arranged on the pressure side, or the second space (24) is arranged on the suction side and the first space (23) is arranged on the pressure side.
15. The pump (1) according to any one of the preceding claims, characterised in that the spring (5) comprises an elastomer material or polymer material and is for example formed from an elastomer material or polymer material or from a metal spring which is partially or completely coated in the elastomer material or polymer material, or by injection-moulding the elastomer material or polymer material around the metal spring.

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