WO2014001193A2

WO2014001193A2 - Pendulum-slide cell pump

Info

Publication number: WO2014001193A2
Application number: PCT/EP2013/062902
Authority: WO
Inventors: André MAEDER; Christian Richter
Original assignee: Mahle International Gmbh
Priority date: 2012-06-25
Filing date: 2013-06-20
Publication date: 2014-01-03
Also published as: DE102012210781A1; WO2014001193A3

Abstract

The invention relates to a pendulum-slide cell pump (1) for pumping a liquid, in particular for supplying lubricant to an internal combustion engine, comprising a stator (2), an outer rotor (3), which is arranged in the stator (2) such as to be rotatable on the stator, and an inner rotor (4), which is arranged in the outer rotor (3) and has a driving connection to the outer rotor (3) by means of pendulum slides (5). A reduced temperature dependency of the radial support of the outer rotor (3) on the stator (2) results if the outer rotor (3) is rotatably supported on the stator (2) by means of an inner bearing (9).

Description

Pendelschieberzellenpunnpe

The present invention relates to a Pendelschieberzellenpunnpe with the features of the preamble of claim 1.

From DE 10 2010 041 550 A1 discloses a Pendelschieberzellenpunnpe is known, which has a stator, arranged in the stator and rotatably mounted thereon outer rotor and an outer rotor arranged in the inner rotor, which is drivingly connected via pendulum slide with the outer rotor. In the known Pendelschieberzellenpunnpe, the stator has an outer rotor enclosing bearing ring, on the inside of the outer rotor is rotatably mounted with its outer side.

From DE 10 2006 021 252 A1 a vane pump is known in which a rotor is rotatably arranged in a stator, wherein the rotor has radially extending slots for receiving wings, which are arranged in the slots exclusively radially adjustable. The wings are coupled radially on the outside with sliding shoes, which slide radially outward on an inner peripheral surface of the stator in the circumferential direction. Axial front side of the stator is equipped with guide rings, the sides facing each other each have an axially open, circumferentially closed circumferential guide groove, in which a circumferentially closed circumferential, the inner peripheral surface having coat of the stator and the sliding shoes engage axially. In the known vane pump, the sliding blocks are supported radially on the outside of the stator shell.

In a Pendelschieberzellenpunnpe of the type mentioned, comprising a stator, an outer rotor and an inner rotor, there is a desire to make the stator of a light metal or a light metal alloy, while the outer rotor is to be made of iron or of an iron alloy. However, a typical light metal, such as aluminum, has a coefficient of thermal expansion about twice the thermal expansion coefficient of iron. In the known pendulum shear cell pump, in which the outer rotor is externally mounted on the stator, that is supported radially outward on the stator, an increasing temperature leads to an enlargement of the bearing gap, which is located radially between the outer side of the outer rotor and the inside of the stator and in which a lubricant film is suitably present. As the temperature increases, however, the viscosity of the lubricant used, usually an oil, decreases. As a result, the capacity of the bearing with respect to the supportable forces and the realizable speeds is limited. On the other hand, if the known penile pusher cell pump is designed such that an optimum bearing gap between the outer rotor and the stator prevails in an intended operating temperature window, this bearing gap is clearly too small for a cold pendulum pusher cell pump. In particular, it may even come to a press fit between the stator and outer rotor.

The present invention addresses the problem of providing an improved embodiment for a pendulum slide cell pump of the type mentioned, which is characterized in particular by a comparatively high load capacity and / or by a reduced temperature dependence.

This problem is solved according to the invention by the subject matter of the independent claim. Advantageous embodiments are the subject of the dependent claims.

The invention is based on the general idea, the outer rotor not outsourced, but to design internally stored. This means that the Outer rotor is radially supported on the stator only inwardly, in particular over a bearing gap, preferably with oil film. By the inner bearing of the outer rotor on the stator is achieved that the bearing gap in the event that the stator when heating the pendulum slide cell pump expands more than the outer rotor is smaller. Since heating of the pendulum slide cell pump also heats the respective lubricant at the same time, its viscosity decreases, as a result of which the bearing effect can be ensured despite the reduced bearing gap. In this case, for a cold state in which the pendulum slide cell pump has, for example, ambient temperature, the bearing gap is larger than required, but in the cold state, the viscosity of the lubricant is comparatively large, whereby the bearing effect is sufficient even in a large bearing gap. The inventive proposal to store the outer rotor via an inner bearing on the stator, reduces the temperature dependence of the radial bearing and thus makes it easier to use different materials for the stator and outer rotor.

The idea of the invention is particularly evident if, according to an advantageous embodiment, the outer rotor is mounted radially on the stator exclusively via the inner bearing. This simplifies the radial bearing of the outer rotor, which allows greater manufacturing tolerances. In the absence of external bearing of the outer rotor on the stator, the outer rotor can also be particularly easy to expand radially outward. Radially, the outer rotor is thus stored, preferably exclusively, on the inner bearing on the stator. As a result, an axial bearing of the outer rotor on the stator is not excluded. Basically, a one-sided axial bearing can be provided as well as a two-sided axial bearing of the outer rotor on the stator. Likewise, an embodiment is conceivable in which can be dispensed with an axial bearing between the outer rotor and stator. In this case is the outer rotor on the stator then only radially and preferably exclusively mounted on the inner bearing on the stator.

Particularly useful is an embodiment in which the outer rotor has a closed in the circumferential direction encircling ring body, which may be configured in particular in one piece or in one piece. The outer rotor is characterized in the circumferential direction quasi undivided or unsegmented and thus receives a particularly simple structure, which reduces the manufacturing cost.

According to a particularly advantageous embodiment, the invention proposes to equip the outer rotor for realizing the inner bearing at its axial end faces in each case with an axially projecting, circumferential in the circumferential ring collar. Complementarily, the stator for each ring collar can be equipped with an axially open towards the outer rotor, circumferential in the circumferential direction of the annular groove in which the respective annular collar projects axially. Furthermore, it can be provided that an inner wall of the stator radially inwardly delimiting the respective annular groove has an outer sliding bearing surface radially on the outside. Furthermore, it can be provided complementary to the fact that the respective annular collar in the respective annular groove radially inner has an inner sliding bearing surface of the outer rotor, which cooperates for sliding bearing of the outer rotor on the stator with the respective outer sliding bearing surface. The cooperating inner sliding bearing surfaces and outer sliding bearing surfaces thus form the inner bearing of the outer rotor on the stator. The proposed construction also means that the bearing surfaces in the axial direction can be made relatively small, which simplifies the production of a complete lubricating film in the respective bearing gap and reduces the risk of dry running. According to an advantageous development may be formed radially between the outer rotor and the stator circumferential in the circumferential direction an annular gap extending from one annular groove to the other annular groove. This ensures that the outer rotor can not be supported radially on the outside of the stator. The outer rotor is thus arranged radially outside contactless to the stator.

According to another advantageous embodiment can be formed radially between the respective inner sliding bearing surface and the associated outer sliding bearing surface in each case a circumferential in the circumferential direction lubricant gap. Such a lubricant gap is a bearing gap which is filled with a suitable lubricant, preferably a lubricating oil. By providing such a lubricant gap, the support between the outer rotor and stator in the radial direction is not directly, but indirectly via a

Lubricant film.

In another advantageous embodiment, the stator and the outer rotor can be made of different materials, wherein the stator material has a larger thermal expansion coefficient than the outer rotor material. This design causes the stator to expand more than the outer rotor when the temperature increases. Due to the here proposed inner bearing of the outer rotor on the stator, such a temperature increase leads to a reduction in the bearing gap between outer rotor and stator, which is largely uncritical in the case of a lubricant gap, since an increase in bearing friction due to the reduction of the gap width by reducing the viscosity of the lubricant used is substantially compensated. Preferably, the stator material may be a light metal material, while the outer rotor material is preferably an iron material.

Particularly advantageous is an embodiment in which the Außengleitlager- surfaces and the inner sliding bearing surfaces are designed in terms of their radial dimensions to a expected during operation of the pendulum slide cell pump maximum temperature. In general, it is proposed here to design the inner bearing of the outer rotor on the stator to be expected during operation of the pendulum slide cell pump maximum temperature, such that at the maximum temperature optimum storage in terms of high transferable forces and high speeds can be realized. The inner bearing has the consequence that at smaller temperatures, the gap width increases, if the stator material has a larger thermal expansion coefficient than the outer rotor material. Lower temperatures, however, increase the viscosity of the lubricant, whereby further sufficient bearing action can be realized.

In another advantageous embodiment, the outer rotor may have a plurality of magnets arranged distributed in the circumferential direction. Appropriately, the stator can then be equipped with a plurality of coils distributed in the circumferential direction. Overall, an electric motor and / or a generator can be realized thereby, whereby the pendulum slide cell pump has an increased functional density. For example, can be driven via the integrated electric motor, the outer rotor to produce the pumping function of the pendulum slide cell pump. In contrast, if an external drive of the pendulum slide cell pump, which drives the inner rotor via a drive shaft, is provided and has excess energy, electrical energy can be obtained via the generator. According to another advantageous embodiment, the stator may be divided in a perpendicular to the axial direction extending separation plane into two stator parts, which are fixed to each other and each having one of the annular grooves. This simplifies the assembly of the pendulum slide cell pump.

According to an advantageous development, the one stator part can form an axially open stator housing, in which the outer rotor is inserted axially, while the other stator part forms a stator ring, which forms the axially open side of the stator

Stator housing closes. This design also simplifies the assembly of the pendulum slide cell pump.

According to another development, it can be provided that the stator ring extends axially substantially only in the region of the associated annular groove. Thus, complex internals can be accommodated in the stator housing, while the stator has a simple structure. Overall, this also simplifies the assembly of the pendulum slide cell pump.

Advantageously, the outer rotor can be a one-piece integral part. For example, the outer rotor is a single casting or sintered part.

Additionally or alternatively, the inner rotor may be an integral part made of one piece, such as a single casting or sintered part.

According to another advantageous embodiment it can be provided that the pendulum slides are arranged radially inward in axial outer grooves of the inner rotor, which extend radially with respect to the axis of rotation of the inner rotor, pendulum. In addition, the pendulum slides can be radially outward in axial inner grooves of the outer rotor, which extend radially to the axis of rotation of the outer rotor, be arranged pendulum.

For generating a pumping action, the axes of rotation of inner rotor and outer rotor are arranged eccentrically to one another. In order to be able to change the pumping action at a constant speed, the pendulum slide cell pump can be equipped with an adjusting device for adjusting the eccentricity between the axes of rotation of the inner rotor and the outer rotor.

Other important features and advantages of the invention will become apparent from the dependent claims, from the drawings and from the associated figure description with reference to the drawings.

It is understood that the features mentioned above and those yet to be explained below can be used not only in the particular combination given, but also in other combinations or in isolation, without departing from the scope of the present invention.

Preferred embodiments of the invention are illustrated in the drawings and will be described in more detail in the following description, wherein like reference numerals refer to the same or similar or functionally identical components.

Show, in each case schematically,

1 is an isometric sectional view of a pendulum pusher cell pump,

Fig. 2 is an axial view of the Pendelschieberzellenpunnpe. According to FIGS. 1 and 2, a pendulum slide cell pump 1, by means of which a liquid, in particular a lubricant, preferably a lubricating oil, can be conveyed, comprises a stator 2, an outer rotor 3 and an inner rotor 4, which is connected to the outer rotor 3 via a plurality of pendulum slides 5 is drive connected. The outer rotor 3 is arranged coaxially with respect to its axis of rotation 6 in the stator 2 and rotatably mounted thereon. The inner rotor 4 is, however, arranged in the outer rotor 3, wherein a rotation axis 7 of the inner rotor 4, although parallel to the axis of rotation 6 of the outer rotor 3, but is arranged eccentrically thereto. A corresponding eccentricity is denoted by 8 in FIGS. 1 and 2.

Suitably, the outer rotor 3 has a particularly simple structure. In the example, the outer rotor 3 in the circumferential direction, which is indicated in Figures 1 and 2 by a double arrow 12, designed unsegmented or undivided. As a result, the outer rotor 3 has an unspecified ring body, which rotates closed in the circumferential direction 12 and is preferably configured in one piece.

The outer rotor 3 is mounted on the stator 2 via an inner bearing 9, in which the outer rotor 3 is supported radially inwardly on the stator 2. For radial mounting of the outer rotor 3 on the stator 2, only this inner bearing 9 is provided, so in particular no external storage.

To realize the inner bearing 9 of the outer rotor 3 has at its axial end faces 10 each have an annular collar 1 1, which projects axially from the other end face 10 and in the circumferential direction 12 rotates closed. The stator 2 now has for each annular collar 1 1 to the outer rotor 3, that is axially inwardly open annular groove 13, which also completely rotates in the circumferential direction 12. In this case, the respective annular collar 1 1 protrudes into the respective associated annular groove 13th axially into it. Furthermore, the respective annular groove 13 has an inner wall 14, which bounds the respective annular groove 13 radially inwardly and which has a radially outside outer sliding bearing surface 15. The respective annular collar 1 1 now has within the respective annular groove 13 radially inner an inner sliding bearing surface 16. The respective inner sliding bearing surface 16 now interacts with the respective outer sliding surface 15 for sliding bearing of the outer rotor 3 on the stator 2 together. The two inner sliding bearing surfaces 16 together with the two outer sliding bearing surfaces 15 thus form the inner bearing 9 of the outer rotor 3 on the stator 2.

Radially between the outer rotor 3 and the stator 2, an annular gap 17 is formed, which rotates closed in the circumferential direction 12. This annular gap 17 extends in the axial direction from one annular groove 13 to the other annular groove 13. The axial direction runs parallel to the axes of rotation 6, 7.

Radially between the respective inner sliding bearing surface 16 and the associated outer sliding bearing surface 15, a lubricant gap 18 is formed, which rotates closed in the circumferential direction 12. The respective lubricant gap 18 is a bearing gap in which a lubricant, in particular lubricating oil is located. In the respective lubricant gap 18, the respective inner sliding bearing surface 16 and the associated outer sliding bearing surface 15 thus cooperate via a lubricant film in order to realize the respective sliding bearing of the outer rotor 3 on the stator 2. A radial gap width of the lubricant gap 18 is smaller than a radial width of the annular gap 17.

The stator 2 is expediently made of a different material than the outer rotor 3. For example, the stator 2 consists of a stator material, which may be, for example, a light metal material, in particular aluminum-based, while the outer rotor 3 consists of a Außenro- gate material which is, for example, a ferrous material can act. Thus, stator 2 and outer rotor 3 have different coefficients of thermal expansion, wherein the coefficient of expansion of the stator 2 is usually greater than that of the outer rotor 3. The radial dimensions of the outer sliding bearing surfaces 15 and the associated inner sliding bearing surfaces 16 are preferably designed for a maximum temperature during operation of the Pendulum pusher pump 1 is expected. In the material combination presented here, the inner bearing 9 causes the lubricant gap 18 to become smaller in the radial direction with increasing temperature of the pendulum slide cell pump 1. At the same time, the viscosity of the lubricant used decreases, whereby a highly efficient, narrow lubricant gap 18 for the hot operating state of the pendulum slide cell pump 1 can be achieved. For the cold operation of Pendelschieberzellenpunnpe 1 then there is a correspondingly larger lubricant gap 18, in which, however, the lubricant has a correspondingly greater viscosity in order to ensure a sufficiently stable storage between outer rotor 3 and stator 2 in the cold operating condition.

According to FIG. 1, the outer rotor 3 can carry a plurality of magnets 19 arranged distributed in the circumferential direction 12. The stator 2 may suitably have a plurality of electromagnetic coils, not shown here, so as to produce an electric motor or a generator. In an electric motor operation, the pendulum slider cell pump 1 can be driven via the outer rotor 3. In a generator mode, an indicated in Figure 2, rotatably connected to the inner rotor 4 drive shaft 20, the Pendelschieberzellenpunnpe 1 drive via the inner rotor 4.

In the example of Figure 1, the stator 2 is divided in a parting plane 21 in two stator parts 22, 23. The parting plane 21 extends perpendicular to the axial direction, that is perpendicular to the axes of rotation 6, 7. The stator parts 22, 23 are anei- fastened each other and each have one of the annular grooves 13. The one stator part 22 forms an axially open stator housing 24 into which the outer rotor 3 can be inserted axially. The other stator part 23 forms a stator ring 25, which closes the axially open side of the stator housing 24. In the example, the stator ring 25 extends in the axial direction substantially only in the region of the associated annular groove 13.

Preferably, the outer rotor 3 is an integral part made of one piece. Preferably, the outer rotor 3 is designed as a sintered part or as a casting. Also, the inner rotor 4 may be an integral part made of one piece, which is preferably a sintered part or casting.

As can be seen in particular from FIG. 2, the inner rotor 4 has axial outer grooves 26, which are radially oriented with respect to the axis of rotation 7 of the inner rotor 4. The outer rotor 3 has axial inner grooves 27, which are radially oriented with respect to the axis of rotation 6 of the outer rotor 3. The pendulum slide 5 are now radially inserted radially into one of the outer grooves 26 of the inner rotor 4 and radially outwardly into one of the inner grooves 27 of the outer rotor 3 radially and disposed therein each pendulum.

Claims

claims

1 . Pendulum slide cell pump for conveying a liquid, in particular for supplying lubricant to an internal combustion engine, comprising a stator (2), an outer rotor (3) arranged in the stator (2) and rotatably mounted thereon, and an inner rotor (4) arranged in the outer rotor (3) via pendulum slide (5) is drive-connected to the outer rotor (3),

characterized,

the outer rotor (3) is rotatably mounted on the stator (2) via an inner bearing (9).

2. Pump according to claim 1

characterized,

the outer rotor (3) is mounted radially on the stator (2) exclusively via the inner bearing (9).

3. Pump according to claim 1 or 2,

characterized,

in that the outer rotor (3) has a ring body which runs closed in the circumferential direction (12).

4. Pump according to one of claims 1 to 3

characterized, - That the outer rotor (3) at its axial end faces in each case an axially projecting, in the circumferential direction (12) encircling annular collar (1 1),

- That the stator (2) for each annular collar (1 1) to the outer rotor (3) open in the circumferential direction (12) circumferential annular groove (13) into which the respective annular collar (1 1) protrudes axially,

in that an inner sliding wall (14) radially inwardly delimiting the respective annular groove (13) has an outer sliding bearing surface (15) radially on the outside;

- That the respective annular collar (1 1) in the respective annular groove (13) radially inside a Innengleitlagerflache (16) which cooperates for sliding mounting of the outer rotor (3) on the stator (2) with the respective outer sliding bearing surface (15).

5. Pump according to one of claims 1 to 4,

characterized,

that between the outer rotor (3) and the stator (2) in the circumferential direction (12) circumferential annular gap (17) is formed, which extends from the one annular groove (1) to the other annular groove (13).

6. Pump according to claim 4 or 5,

characterized,

in that a lubricant gap (18) circulating in the circumferential direction (12) is formed radially between the respective inner sliding bearing surface (16) and the associated outer sliding bearing surface (15).

7. Pump according to one of claims 1 to 6,

characterized,

that the stator (2) and the outer rotor (3) are made of different materials, wherein the stator material has a larger thermal expansion coefficient than the outer rotor material.

8. Pump according to claim 7

characterized,

that the stator material is a light metal material, while the outer rotor material is an iron material.

9. Pump according to at least one of claims 4 to 6

characterized,

that the outer sliding bearing surfaces (15) and the inner sliding bearing surfaces (16) are designed with regard to their radial dimensions to a maximum temperature to be expected during operation of the pendulum slide cell pump (1).

10. Pump according to one of claims 1 to 9,

characterized,

the outer rotor (3) carries a plurality of magnets (19) arranged distributed in the circumferential direction (12).

1 1. Pump according to one of claims 1 to 10

characterized,

in that the stator (2) is divided in a parting plane (21) extending perpendicularly to the axial direction into two stator parts (22, 23) which are fastened to one another and each have one of the annular grooves (13).

12. Pump according to claim 1 1,

characterized,

in that the one stator part (22) forms an axially open stator housing (24) in which the outer rotor (3) is axially inserted, while the other stator part (23) forms a stator ring (25) which forms the axially open side of the stator housing (24 ) closes.

13. Pump according to claim 12,

characterized,

that the stator ring (25) extends axially substantially only in the region of the associated annular groove (1).

14. Pump according to one of claims 1 to 13,

characterized,

the outer rotor (3) is an integral part made in one piece.

15. Pump according to one of claims 1 to 14,

characterized,

in that the inner rotor (4) is an integral part made in one piece.

16. Pump according to one of claims 1 to 15,

characterized,

in that the pendulum slides (5) are arranged radially inwardly in axial outer grooves (26) of the inner rotor (4) and radially outwardly in axial inner grooves (27) of the outer rotor (3) in each case in a pendulum manner.