Vane cell pump comprising a pressure equalization connection

Abstract

A vane cell pump, including: a delivery chamber having an inlet and an outlet; a rotor which is arranged in the delivery chamber and has a rotor body and vanes which are accommodated by the rotor body such that they can be shifted radially; an end-facing wall which delineates the delivery chamber on an axial end-facing side; and a supporting element which is arranged axially between the end-facing wall and the rotor body and which supports the vanes at their radially inner vane ends, wherein the rotor body, the supporting element and each two vanes which are adjacent in the circumferential direction of the rotor form chambers, the volume of which varies when the rotor is rotating. A pressure equalization connection fluidically connects at least two of the chambers to each other.

Claims

1. A vane cell pump, comprising: a. a delivery chamber comprising an inlet and an outlet; b. a rotor which is arranged in the delivery chamber and comprises a rotor body and vanes which are accommodated in a radially shiftable manner by the rotor body; c. an end-facing wall which delineates the delivery chamber on an axial end-facing side; d. a supporting element which is arranged axially between the end-facing wall and the rotor body and which supports the vanes at their radially inner vane ends, e. a delivery chamber wall which forms a running surface for the radially outer vane ends of the vanes, f. wherein the rotor body, the delivery chamber wall and each two vanes which are adjacent in the circumferential direction form delivery cells which are delineated by the vanes radially outside the rotor body in the circumferential direction and transport fluid from the inlet to the outlet, g. wherein the rotor body, the supporting element and each two vanes which are adjacent in the circumferential direction of the rotor form chambers, the volume of which varies when the rotor is rotating, and h. wherein an axially protruding edge of the rotor isolates the chambers and the delivery cells from each other, and i. a pressure equalization connection which connects at least two of the chambers to each other fluidically which are formed radially inside the axially protruding edge, j. wherein the pressure equalization connection comprises at least one groove formed in one or both of (i) the end-facing wall or in the rotor axially adjacent to the vanes, and (ii) at least one of the vanes.

2. The vane cell pump according to claim 1, wherein the rotor body and the end-facing wall form an axial sealing gap, and wherein the pressure equalization connection is formed radially inside the axial sealing gap.

3. The vane cell pump according to claim 1, wherein the at least one groove is formed in the end-facing wall or in the rotor by a circle, a circular segment or multiple separate circular segments, concentrically with respect to a rotational axis of the rotor.

4. The vane cell pump according to claim 1, wherein the at least one groove is separated from one or both of the inlet and the outlet.

5. The vane cell pump according to claim 1, further comprising a drive shaft, for driving the rotor, which is mounted in at least one bearing, wherein the at least one groove is separated from the bearing.

6. The vane cell pump according to claim 1, wherein in order to accommodate the vanes in a radially shiftable manner, the rotor body comprises vane receptacles which each comprise a base which forms a radially inner end of the vane receptacle, wherein the at least one groove is spaced radially from the base of the vane receptacles.

7. The vane cell pump according to claim 6, wherein the at least one groove extends radially outward from the base of the vane receptacles.

8. The vane cell pump according to claim 1, wherein the at least one groove extends radially outward from at least substantially outside the supporting element.

9. The vane cell pump according to claim 1, wherein the vane cell pump is an engine lubricant pump of a motor vehicle or a transmission pump of a motor vehicle.

10. A vane cell pump, comprising: a. a delivery chamber comprising an inlet and an outlet; b. a rotor which is arranged in the delivery chamber and comprises a rotor body and vanes which are accommodated in a radially shiftable manner by the rotor body; c. an end-facing wall which delineates the delivery chamber on an axial end-facing side; d. a supporting element which is arranged axially between the end facing wall and the rotor body and which supports the vanes at their radially inner vane ends, e. a delivery chamber wall which forms a running surface for the radially outer vane ends of the vanes, f. wherein the rotor body, the delivery chamber wall and each two vanes which are adjacent in the circumferential direction form delivery cells which are delineated by the vanes radially outside the rotor body in the circumferential direction and transport fluid from the inlet to the outlet, g. wherein the rotor body, the supporting element and each two vanes which are adjacent in the circumferential direction of the rotor form chambers, the volume of which varies when the rotor is rotating, and h. wherein an axially protruding edge of the rotor isolates the chambers and the delivery cells from each other, and i. a pressure equalization connection which connects at least two of the chambers to each other fluidically which are formed radially inside the axially protruding edge, j. wherein the pressure equalization connection comprises at least one passage hole in at least one of the vanes.

11. A vane cell pump, comprising: a. a delivery chamber comprising an inlet and an outlet; b. a rotor which is arranged in the delivery chamber and comprises a rotor body and vanes which are accommodated in a radially shiftable manner by the rotor body; c. an end-facing wall which delineates the delivery chamber on an axial end-facing side; d. a supporting element which is arranged axially between the end facing wall and the rotor body and which supports the vanes at their radially inner vane ends, e. a delivery chamber wall which forms a running surface for the radially outer vane ends of the vanes, f. wherein the rotor body, the delivery chamber wall and each two vanes which are adjacent in the circumferential direction form delivery cells which are delineated by the vanes radially outside the rotor body in the circumferential direction and transport fluid from the inlet to the outlet, g. wherein the rotor body, the supporting element and each two vanes which are adjacent in the circumferential direction of the rotor form chambers, the volume of which varies when the rotor is rotating, and h. wherein an axially protruding edge of the rotor isolates the chambers and the delivery cells from each other, and i. a pressure equalization connection which connects at least two of the chambers to each other fluidically which are formed radially inside the axially protruding edge, j. wherein the pressure equalization connection comprises one or both of (i) an enlarged axial sealing gap between the supporting element and the end-facing wall and (ii) an enlarged axial sealing gap between at least one of the vanes and the end-facing wall.

12. The vane cell pump according to claim 11, wherein the rotor body and the end-facing wall form an axial sealing gap, and wherein the one or both of the enlarged axial sealing gap between the supporting element and the end-facing wall and the enlarged axial sealing gap between the at least one of the vanes and the end-facing wall is/are at least 50% wider than the axial sealing gap which is formed between the rotor body and the end-facing wall.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the following, an example embodiment of a vane cell pump in accordance with an aspect of the invention is described in more detail on the basis of figures. Features essential to an aspect of the invention which can only be gathered from the figures form part of the scope of the invention.

(2) The figures show:

(3) FIG. 1 a longitudinal section of a tandem pump comprising a vane cell pump in accordance with an aspect of the invention, plus the detailed view X;

(4) FIG. 2 a plan view and a longitudinal section of an end-facing wall at the cover end of the vane cell pump;

(5) FIG. 3 a plan view and a longitudinal section of an end-facing wall at the base end of the vane cell pump;

(6) FIG. 4 the longitudinal section of FIG. 1 together with the detailed view Y;

(7) FIG. 5 a plan view of the vane cell pump with the end-facing wall at the base end absent.

DETAILED DESCRIPTION OF THE INVENTION

(8) FIG. 1 shows a longitudinal section of a tandem pump of a motor vehicle comprising a vane cell pump 1 and another pump 22 which are driven by a common drive shaft 12. The vane cell pump 1 can be formed as an engine lubricating oil pump, and the other pump 22 can be formed as a vacuum pump. An aspect of the invention is not restricted to arranging the vane cell pump 1 in a tandem pump. Forming it as a tandem pump, and how the other pump 22 is formed, is not relevant to performing an aspect of the invention. The vane cell pump 1 can readily be formed as an independent pump, for example as an engine lubricating oil pump.

(9) The vane cell pump 1 comprises a rotor 3, 4 comprising a rotor body 3 and vanes 4 which are accommodated by the rotor body 3 such that they can be shifted radially. The rotor 3, 4 is arranged in a delivery chamber 2. The delivery chamber 2 comprises a delivery chamber wall 21 which forms a running surface for the radially outer vane ends of the vanes 4. The vane cell pump 1 comprises a drive shaft 12 which is non-rotationally connected to the rotor 3, 4 and to a drive which is not presented in more detail. The rotor 3, 4 can be driven about its rotational axis by the drive.

(10) The vane cell pump 1 comprises a first end-facing wall 5 and a second end-facing wall 6 which axially delineate the delivery chamber 2 on one end-facing side each. The first end-facing wall 5 is formed by a base or a base plate. The second end-facing wall 6 is formed by a cover or a cover plate.

(11) The axial ends of the rotor body 3 are formed in the shape of a cup, such that each of the axial ends of the rotor body 3 forms an annular, axially protruding edge 33 which progresses on a running surface 51 of the end-facing wall 5 at the base end and/or a running surface 61 of the end-facing wall 6 at the cover end when the rotor 3, 4 is driven. The axially protruding edge 33 of the first axial end of the rotor body 3 forms an axial sealing gap 31 with the running surface 51 of the end-facing wall 5 at the base end. The axially protruding edge 33 of the second axial end of the rotor body 3 forms an axial sealing gap 32 with the running surface 61 of the end-facing wall 6 at the cover end. By being formed in the shape of a cup, each of the axial ends of the rotor body 3 comprises an accommodating space 34 which is surrounded by the axially protruding edge 33 of the respective end. The accommodating space 34 is designed for accommodating or arranging a supporting element 8 for supporting the vanes 4.

(12) The vane cell pump 1 comprises a pressure equalization connection 10 which in the example embodiment shown comprises a groove 9 which is formed in the upper side of the end-facing wall 5 and end-facing wall 6, which faces the rotor body 3.

(13) The axial sealing gaps 31, 32 isolate the respective accommodating space 34 in which the supporting element 8 is arranged. The supporting element 8 forms an axial sealing gap 81 with the end-facing wall 5 at the base end and/or a sealing gap 82 with the end-facing wall 6 at the cover end. The supporting element 8, the rotor body 3, each two vanes 4 which are adjacent in the circumferential direction of the rotor 3, 4, and the respective end-facing wall 5, 6 form chambers 18 or rotor interior space chambers in the accommodating space 34, the volume of which varies periodically when the rotor 3, 4 is driven. The groove 9 of the pressure equalization connection 10 connects at least two adjacent chambers 18 to each other, such that pressure equalization occurs between these chambers 18. The groove 9 is formed as a closed annular groove. It fluidically connects all the chambers 18 permanently to each other. The groove 9 can however also be formed as one or more circular segments, such that only selected chambers 18 are connected to each other.

(14) The vane cell pump 1 also comprises an inlet E which is assigned to a low-pressure side of the vane cell pump 1 and through which fluid can flow into the delivery chamber 2. The fluid can leave the delivery chamber 2 again through an outlet A which is assigned to a high-pressure side of the vane cell pump 1.

(15) FIG. 2 shows a longitudinal section and a plan view of the end-facing wall 6 at the cover end or, respectively, the upper side of the end-facing wall 6 which faces the rotor 3, 4. The running surface 61 for the rotor body 3, the inlet E, the outlet A and the bearing 11 for the drive shaft 12 can be seen in FIG. 2. The groove 9, which is formed in the upper side of the end-facing wall 6 which faces the rotor 3, 4, can also be seen.

(16) A first sealing stay 13 comprising a crest 14, and a second sealing stay 15 comprising a crest 16, can also be seen in the plan view. The groove 9 is formed as a continuous annular groove which does not feed into either the inlet E, the outlet A or the bearing 11. The pressure equalization connection 10, in this case the groove 9, connects all the chambers 18 to each other in the example embodiment shown. The groove 9 can however also be formed as one or more separate circular portions. A circular portion can then for example extend only from the crest 16 of the sealing stay 15 up to the crest 14 of the sealing stay 13. This does not connect all the chambers 18 to each other, but does connect the smallest chamber 18 and the largest chamber 18, thus enabling the pressure in the smallest chamber 18, i.e. the chamber 18 exposed to the greatest load, to be relieved.

(17) FIG. 3 shows substantially the same as FIG. 2, this time embodied on the end-facing wall 5 at the base end. Reference is therefore made to the description of FIG. 2, which shows the same features as FIG. 3.

(18) FIG. 4 shows the vane cell pump of FIG. 1 together with the setting ring 19 using which the delivery amount of the vane cell pump 1 can be adjusted. The setting ring 19 forms the delivery chamber wall 21. The delivery chamber wall 21 forms a running surface for the radially outer vane ends of the vanes 4. The vane cell pump 1 comprises an end-facing wall 6 on which the axially protruding edge 33 of the rotor body 3 progresses along the running surface 61 at the first axial end, and an axially opposite end-facing wall 5 on which the axially opposite, axially protruding edge 33 of the rotor body 3 progresses along the running surface 51 at the second axial end.

(19) The detail shows the axial sealing gap 31 which the edge 33 of the rotor body 3 forms with the upper side of the end-facing wall 5 which faces the rotor body 3. The supporting element 8 is arranged in the accommodating space 34 and, together with the rotor body 3 and two vanes 4 which are adjacent in the circumferential direction of the rotor 3, 4, forms the chambers 18 which are fluidically connected to each other by the pressure equalization connection 10, in this case the groove 9, such that pressure equalization occurs between the chambers 18.

(20) FIG. 5 is a view into a vane cell pump 1 showing the setting ring 19 which is biased towards maximum eccentricity between the rotor 3, 4 and the setting ring 19, i.e. full delivery, by a spring element 20. In order to adjust the setting ring 19 and therefore the delivery rate, the setting ring 19 can be hydraulically adjusted, against the spring force of the spring element 20, by a setting pressure in a setting chamber. The rotor 3, 4 comprising the axially protruding edge 33, which forms the axial sealing gap 31 with the end-facing wall 5 at the base end along the running surface 51, can be seen. The rotor 3, 4 comprises vanes 4 which are pressed or pushed against the delivery chamber wall 21 of the delivery chamber 2 by the supporting element 8 in every setting position of the setting ring 19. The vanes 4 sub-divide the delivery chamber 2 into delivery cells 7 in which fluid can be transported from the inlet E to the outlet A. The rotor body 3 also comprises vane receptacles 41 which comprise a slot region 42 and a base region 43 comprising a base 17.

(21) The supporting element 8, two vanes 4 which are adjacent in the circumferential direction of the rotor 3, 4, and the rotor body 3 form the chambers 18, the volume of which varies when the rotor 3, 4 is rotating. The pressure equalization connection 10 in the form of the groove 9 is indicated in FIG. 5 by dashed lines. The groove 9 lies in the accommodating space 34 which is radially delineated by the axially protruding edge 33 of the rotor body 3, and outside the base regions 43 of the vane receptacles 41. The groove 9 does not feed into any of the base regions 43 of the vane receptacles 41. It extends radially between the axially protruding edge 33 and the base region 43.

LIST OF REFERENCE SIGNS

(22) 1 vane cell pump 2 delivery chamber 21 delivery chamber wall 3 rotor body 31 sealing gap 32 sealing gap 33 edge 34 accommodating space 4 vane 41 vane receptacle 42 slot region 43 base region 5 end-facing wall 51 running surface 6 end-facing wall 61 running surface 7 delivery cell 8 supporting element 81 sealing gap 82 sealing gap 9 groove 10 pressure equalization connection 11 bearing 12 drive shaft 13 sealing stay 14 crest 15 sealing stay 16 crest 17 base 18 chamber 19 setting ring 20 spring element 22 pump A outlet E inlet