FLOW CHANNELING STRUCTURE

Abstract

A rotary pump for delivering fluid includes: a pump housing having a low-pressure inlet and a high-pressure outlet for the fluid to be delivered; and a delivery rotor rotatable about a rotational axis in the pump housing and including a rotor base body and multiple deliverers distributed over the circumference of the rotor base body for delivering fluid from the low-pressure inlet to the high-pressure outlet. When the delivery rotor rotates, the radial and axial outer edges of the deliverers define a delivery region of the pump. The pump includes a flow channeling structure protruding axially into the low-pressure inlet in relation to the rotational axis of the delivery rotor from the pump housing wall in order to influence fluid flowing in the low-pressure inlet. The flow channeling structure arranged axially next to the delivery region and overlaps at least in portions with the delivery region in the radial direction.

Claims

1.-15. (canceled)

16. A rotary pump for delivering a fluid, the rotary pump comprising: (a) a pump housing having a low-pressure inlet and a high-pressure outlet for the fluid to be delivered; and (b) a delivery rotor arranged such that it can be rotated about a rotational axis in the pump housing and comprising (c) multiple delivery means which are distributed over the circumference of the delivery rotor for delivering the fluid from the low-pressure inlet to the high-pressure outlet, wherein (d) when the delivery rotor rotates, the radial and axial outer edges of the delivery means define a delivery region of the rotary pump, and (e) the rotary pump comprises a flow channeling structure which protrudes axially into the low-pressure inlet in relation to the rotational axis and is designed to influence the fluid flowing in the low-pressure inlet, wherein (f) the flow channeling structure is arranged axially next to the delivery region and overlaps at least in portions with the delivery region in the radial direction.

17. The rotary pump according to claim 16, wherein the flow channeling structure comprises an incident flow edge which is spaced apart from the delivery region in the radial direction and/or arranged substantially parallel to the rotational axis.

18. The rotary pump according to claim 16, wherein the width of the flow channeling structure is delineated in the circumferential direction by two side walls, and the circumferentially measured width of the flow channeling structure increases in the flow direction of the fluid to be delivered.

19. The rotary pump according to claim 17, wherein the side walls extend in the radial direction from the incident flow edge up to and into a radial overlap with the delivery region.

20. The rotary pump according to claim 18, wherein a circumferentially measured maximum distance between the two side walls is greater than a circumferentially measured maximum distance between two adjacent delivery means, and/or the circumferentially measured maximum distance between the two side walls is smaller than a circumferentially measured maximum distance between the two outer delivery means of a total of three adjacent delivery means.

21. The rotary pump according to claim 16, wherein a first side wall of the flow channeling structure together with the wall of the low-pressure inlet forms a first inlet sub-channel which is open axially at one end, and the fluid flowing through the first inlet sub-channel is directed in a direction counter to the rotational direction of the delivery rotor.

22. The rotary pump according to claim 16, wherein a second side wall of the flow channeling structure together with the wall of the low-pressure inlet forms a second inlet sub-channel which is open axially at one end, and the fluid flowing through the second inlet sub-channel is directed in a direction corresponding to the rotational direction of the delivery rotor.

23. The rotary pump according to claim 16, wherein a first side wall of the flow channeling structure together with the wall of the low-pressure inlet forms a first inlet sub-channel which is open axially at one end, and the fluid flowing through the first inlet sub-channel is directed in a direction counter to the rotational direction of the delivery rotor, wherein a second side wall of the flow channeling structure together with the wall of the low-pressure inlet forms a second inlet sub-channel which is open axially at one end, and the fluid flowing through the second inlet sub-channel is directed in a direction corresponding to the rotational direction of the delivery rotor, and wherein the first inlet sub-channel and/or the second inlet sub-channel exhibit(s) a cross-section which tapers in the flow direction.

24. The rotary pump according to claim 16, wherein the flow channeling structure is delineated axially by an axial end wall which is embodied, at least in portions, to be concave and/or convex.

25. The rotary pump according to claim 24, wherein the flow channeling structure comprises a first portion which overlaps with the delivery region in the radial direction, wherein the axial end wall exhibits a minimum axial distance from the delivery region in the first portion.

26. The rotary pump according to claim 24, wherein the flow channeling structure comprises a second portion which is provided radially next to the delivery region, wherein the axial end wall is embodied, at least in portions, to be concave and/or convex in the second portion.

27. The rotary pump according to claim 16, wherein a mean line of the flow channeling structure exhibits a curvature in the radial direction.

28. The rotary pump according to claim 16, wherein the flow channeling structure is arranged in the low-pressure inlet such that the fluid flowing in the low-pressure inlet flows onto the flow channeling structure from a radial and/or tangential direction in relation to the rotational axis.

29. The rotary pump according to claim 16, wherein the low-pressure inlet extends from a fluid port on the outer wall of the pump housing up to the delivery region.

30. The rotary pump according to claim 16, wherein the rotary pump is a vane pump or a gear pump.

31. The rotary pump according to claim 16, wherein the flow channeling structure is designed to redirect the fluid flowing in the low-pressure inlet.

32. The rotary pump according to claim 16, wherein the low-pressure inlet extends from a fluid port on the outer wall of the pump housing in a radial and/or tangential direction up to the delivery region.

33. The rotary pump according to claim 18, wherein the side walls extend in the radial direction from the incident flow edge up to and into a radial overlap with the delivery region.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The features described above can be combined with each other as desired, wherever technically expedient and suitable. Other features, combinations of features and advantages of aspects of the invention follow from the following description of example embodiments on the basis of the figures. There is shown:

[0025] FIG. 1 a first sectional representation of an example embodiment of a rotary pump in accordance with the invention;

[0026] FIG. 2 a perspective representation of the sectional representation shown in FIG. 1;

[0027] FIG. 3 a second sectional representation of the example embodiment shown in FIG. 1;

[0028] FIG. 4 a third sectional representation of the example embodiment shown in FIG. 1;

[0029] FIG. 5 a fourth sectional representation of the example embodiment shown in FIG. 1; and

[0030] FIG. 6 a detail of a side view of the example embodiment shown in FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

[0031] FIG. 1 is a sectional representation of an example embodiment of the rotary pump 1 in accordance with the invention. In the example embodiment, the rotary pump 1 is embodied as a vane pump. The rotary pump 1 comprises a pump housing 2 which comprises a low-pressure inlet 3 and a high-pressure outlet 4 for the fluid to be delivered. In order to channel the fluid to be delivered into the interior of the rotary pump 1, the low-pressure inlet 3 comprises a fluid port 3a on the outer wall of the pump housing 2. The fluid port 3a forms an inlet intersection for the low-pressure inlet 3, wherein the low-pressure inlet 3 extends into the pump housing 2. Similarly, the high-pressure outlet 4 comprises a fluid port (not shown) in order to channel the delivered fluid out of the rotary pump 1.

[0032] A delivery rotor 5 which can be rotated about a rotational axis D is provided within the pump housing 2. The delivery rotor 5 is arranged axially between two end faces of the pump housing 2. The delivery rotor 5 comprises a rotor base body 5b and multiple delivery means 5a. The delivery means 5a are distributed over the circumference of the rotor base body 5b. In the example embodiment shown, the delivery means 5a can be moved radially in relation to the rotational axis D and are arranged at equal distances from each other. The radial movement of the delivery means 5a is delineated radially inwards (towards the rotational axis D) by the rotor base body 5b. The radial movement of the delivery means 5a in the opposite direction, i.e. radially outwards (away from the rotational axis D), is delineated by an inner surface area 21 of a setting element 20.

[0033] In an alternative example embodiment (not shown), and in particular when the rotary pump 1 is embodied as an internal gear pump, the delivery rotor 5 could also for example be a gear, the teeth of which form the delivery means 5a.

[0034] While the rotary pump 1 is in operation, the delivery rotor 5 rotates about the rotational axis D, wherein the delivery means 5a are pressed radially outwards towards the inner surface area 21 of the setting element 20 due to the centrifugal force acting on the delivery means 5a. Together with the outer surface area 5c of the rotor base body 5b and the inner surface area 21 of the setting element 20, the axial outer edges of the delivery means 5a define a delivery region 6. The delivery region 6 is therefore an annular volume, the axial width of which corresponds to the width of the delivery means 5a. Each two adjacent delivery means 5a form a delivery cell 7 within the delivery region 6. The fluid to be delivered is supplied to the delivery region 6 or delivery cells 7 via the low-pressure inlet 3. In the delivery region 6, the fluid to be delivered is delivered from the low-pressure inlet 3 to the high-pressure outlet 4, wherein the fluid to be delivered is in particular delivered from the low-pressure inlet 3 to the high-pressure outlet 4 within the delivery cells 7 due to the direct influence of the rotating delivery means 5a.

[0035] The setting element 20 is designed to alter and/or adjust the delivery volume of the rotary pump 1. For this purpose, the setting element 20 can be moved back and forth between at least two positions in relation to the pump housing 2. In the example embodiment, the setting element 20 can be translationally moved, i.e. the setting element 20 is arranged such that it can be shifted in the pump housing 2. The inner surface area 21 of the setting element 20 extends around a central axis (not shown) which is offset in parallel in relation to the rotational axis D of the delivery rotor 5 when the setting element 20 is in a first position. Because the central axis of the setting element 20 is offset in parallel in relation to the rotational axis D of the delivery rotor 5, the setting element 20 exhibits an eccentricity in relation to the delivery rotor 5. FIG. 1 shows the setting element 20 in its first position.

[0036] In the first position, the delivery region 6 comprises a low-pressure region 6a in which the volume of the delivery cells 7 increases in the rotational direction of the delivery rotor 5. When the setting element 20 is in its first position, the delivery region 6 also comprises a high-pressure region 6b which adjoins the low-pressure region 6a in the rotational direction of the delivery rotor 5. In the high-pressure region 6b, the volume of the delivery cells 7 decreases in the rotational direction of the delivery rotor 5. The rotary pump 1 exhibits a maximum delivery volume in the first position.

[0037] In a second position (not shown), the setting element 20 is shifted in the pump housing 2 such that the setting element 20 exhibits a minimum eccentricity or no eccentricity in relation to the delivery rotor 5. In other words, the central axis of the setting element 20 is substantially or almost coaxial with the rotational axis D of the delivery rotor 5 in the second position. The rotary pump 1 exhibits a minimum delivery volume in the second position.

[0038] The first position and second position are preferably end positions of the setting element 20, i.e. the setting element 20 cannot assume a position in which it exhibits a greater eccentricity in relation to the delivery rotor 5 than in the first position and/or a smaller eccentricity in relation to the delivery rotor 5 than in the second position. The setting element 20 can assume multiple intermediate positions, for example any number of intermediate positions, between the first position and the second position.

[0039] The rotary pump 1 comprises a restoring means 8 in order to move the setting element 20 into the first position. The restoring means 8 preferably exerts a restoring force on the setting element 20, wherein the restoring force presses the setting element 20 into the first position. The restoring means 8 can comprise at least one restoring spring 8 which is supported on the one hand on the pump housing 2 and on the other hand on the setting element 20. In the example embodiment, the restoring means 8 comprises two restoring springs 8 which are supported on the one hand on the pump housing 2 and on the other hand on the setting element 20. In order to move the setting element 20 into the second position, the rotary pump 1 comprises a pressure channel 22 and a pressure chamber 23. The pressure chamber 23 extends between the pump housing 2 and the setting element 20. A pressurized fluid can be channeled into the pressure chamber 23 via the pressure channel 22. The fluid pressure prevailing in the pressure chamber 23 acts on the setting element 20, towards the second position, against the restoring force of the restoring means 8. The pressurized fluid can for example be the fluid to be delivered, which is preferably taken from the high-pressure outlet 4 and/or from the high-pressure region 6b.

[0040] The rotary pump 1 also comprises a flow channeling structure 10 which is arranged in the low-pressure inlet 3. The flow channeling structure 10 protrudes axially in relation to the rotational axis D from a wall of the pump housing 2 into the low-pressure inlet 3 (cf. for example FIGS. 2 and 4 to 6). The pump housing 2 and the flow channeling structure 10 are preferably embodied in one part and in particular original-molded with each other. The flow channeling structure 10 has a shape which tapers counter to the flow direction of the fluid to be delivered. A circumferentially measured width of the flow channeling structure 10 increases in the flow direction of the fluid to be delivered.

[0041] The flow channeling structure 10 is arranged in the low-pressure inlet 3 such that the flow channeling structure 10 extends axially next to the delivery region 6, in particular axially next to the low-pressure region 6a. The flow channeling structure 10 overlaps at least partially with the delivery region 6 in the radial direction. In alternative example embodiments which are not shown in the figures, a portion of the flow channeling structure 10 which does not radially overlap with the delivery region 6 could extend in the axial direction through the entire low-pressure inlet 3 and for example divide it. Irrespective of this, it is also conceivable for the portion of the flow channeling structure 10 which does not radially overlap with the delivery region 6 to extend axially over less than 75%, preferably less than 50%, of the axial extent of the delivery region 6, in particular the low-pressure region 6a.

[0042] The fluid flowing in the low-pressure inlet 3 flows onto the flow channeling structure 10 from a radial and/or tangential direction in relation to the rotational axis D. Preferably, it does not flow onto the flow channeling structure 10 from an axial direction. The flow channeling structure 10 is designed to influence, in particular redirect, the fluid flow flowing in the low-pressure inlet 3 or at least some of the fluid flow flowing in the low-pressure inlet 3, i.e. a first sub-flow of the fluid flow is for example redirected and/or deflected by the flow channeling structure 10 in such a way that the first sub-flow is provided with at least a flow direction component which is opposite to the rotational direction of the delivery rotor 5. A second sub-flow of the fluid flow is redirected and/or deflected by the flow channeling structure 10 in such a way that the second sub-flow is provided with at least a flow direction component which corresponds to the rotational direction of the delivery rotor 5.

[0043] The flow channeling structure 10 comprises an incident flow edge 14. The incident flow edge 14 forms a sort of leading edge or front edge of the profile of the flow channeling structure 10. In other words, the incident flow edge 14 is an edge which faces the fluid flowing in the low-pressure inlet 3 and which the fluid hits first when it flows in the low-pressure inlet 3 towards the flow channeling structure 10. The stagnation point of the flow channeling structure 10 is preferably situated on the outer circumference of the incident flow edge 14. Irrespective of this, the incident flow edge 14 is spaced apart from the delivery region 6, in particular the low-pressure region 6a, in the radial direction. The fluid flowing in the low-pressure inlet 3 flows onto the incident flow edge 14 from a radial and/or tangential direction in relation to the rotational axis D. Preferably, it does not flow onto the incident flow edge 14 from an axial direction.

[0044] The flow channeling structure 10 comprises a first side wall 11. The first side wall 11 protrudes axially into the low-pressure inlet 3. The first side wall 11 advantageously extends from the incident flow edge 14 into a radial overlap with the delivery region 6. The first side wall 11 exhibits a minimum distance from the rotational axis D which substantially corresponds to the radius of the outer surface area 5c of the rotor base body 5b. The fluid which flows along the first side wall 11 is redirected by the first side wall 11. The fluid flowing past the first side wall 11 is in particular directed in a direction counter to the rotational direction of the delivery rotor 5.

[0045] An opposite wall of the pump housing 2 facing the first side wall 11 forms a first inlet sub-channel 3b together with the first side wall 11. The first inlet sub-channel 3b is a channel in the low-pressure inlet 3 which is open axially at one end. A sub-flow of the fluid flowing in the low-pressure inlet 3 which flows in the first inlet sub-channel 3b is directed in a direction counter to the rotational direction of the delivery rotor 5 in the first inlet sub-channel 3b.

[0046] The flow channeling structure 10 comprises a second side wall 12. The second side wall 12 protrudes axially into the low-pressure inlet 3. The second side wall 12 advantageously extends from the incident flow edge 14 into a radial overlap with the delivery region 6. The second side wall 12 exhibits a minimum distance from the rotational axis D which substantially corresponds to the radius of the outer surface area 5c of the rotor base body 5b. The fluid which flows along the second side wall 12 is redirected by the second side wall 12. The fluid flowing past the second side wall 12 is in particular directed in a direction counter to the rotational direction of the delivery rotor 5.

[0047] An opposite wall of the pump housing 2 facing the second side wall 12 forms a second inlet sub-channel 3c together with the second side wall 12. The second inlet sub-channel 3c is a channel in the low-pressure inlet 3 which is open axially at one end. A sub-flow of the fluid flowing in the low-pressure inlet 3 which flows in the second inlet sub-channel 3c is directed in a direction corresponding to the rotational direction of the delivery rotor 5 in the second inlet sub-channel 3c.

[0048] The flow channeling structure 10 comprises an axial end wall 13. The axial end wall 13, the detailed shape of which is described more precisely below on the basis of FIGS. 4 to 6, connects the first side wall 11 to the second side wall 12 in the circumferential direction. The axial end wall 13 advantageously extends from the incident flow edge 14 into a radial overlap with the delivery region 6.

[0049] For better comprehension, the sectional representation of the rotary pump 1 shown in FIG. 1 is shown in a perspective representation in FIG. 2. For an explanation of the structure and functionality of the rotary pump 1 depicted in FIG. 2, reference is made to the statements above.

[0050] FIG. 3 shows a second sectional representation of the example embodiment shown in FIG. 1. The perspective of the second sectional representation shown in FIG. 3 corresponds to the perspective in FIG. 1. Unlike FIG. 1, FIG. 3 omits the setting element 20, the delivery rotor 5 and the restoring means 8.

[0051] The representation chosen in FIG. 3 reveals an end face 2a of the pump housing 2. The outer circumference of the end face 2a exhibits the same radius in relation to the rotational axis D as the outer surface area 5c of the rotor base body 5b (not shown in FIG. 3). In alternative example embodiments in which the rotary pump 1 is for example embodied as an internal gear pump 1, the outer circumference of the end face 2a can exhibit the same radius in relation to the rotational axis D as the root circle radius of the internal gear.

[0052] In the example embodiment shown in FIG. 3, the first and second side walls 11, 12 extend in the radial direction up to the outer circumference of the end face 2a. A circumferentially measured distance between the first side wall 11 and the second side wall 12 increases towards the outer circumference of the end face 2a.

[0053] A mean line 17 of the flow channeling structure 10 (also called the flow channeling structure center line 17) has been added to FIG. 3. The mean line 17 extends in the flow direction from the incident flow edge 14 up to the outer circumference of the end face 2a. Irrespective of this, the mean line 17 exhibits a curvature in the radial direction. The mean line 17 is in particular curved radially outwards from the radially inner side towards the fluid port 3a of the low-pressure inlet 3.

[0054] As shown in the example embodiment, the first inlet sub-channel 3b tapers in the flow direction. In other words, the cross-section of the first inlet sub-channel 3b decreases in the flow direction. The first inlet sub-channel 3b is embodied in the shape of a nozzle, such that the flow velocity of the fluid flowing in the first inlet sub-channel 3b increases along the first inlet sub-channel 3b. Irrespective of this, the second inlet sub-channel 3c tapers in the flow direction. In other words, the cross-section of the second inlet sub-channel 3c decreases in the flow direction. The second inlet sub-channel 3c is embodied in the shape of a nozzle, such that the flow velocity of the fluid flowing in the second inlet sub-channel 3c increases along the second inlet sub-channel 3c.

[0055] In an axial view, the flow channeling structure 10 has the shape of a shark fin which is bulged concavely inwards in the profile of the first side wall 11 facing the inflowing fluid and bulged convexly outwards in the profile of the second side wall 12, in order to channel the fluid towards the delivery region 6 in a way which is favorable in terms of flow dynamics.

[0056] FIGS. 4 and 5 show a third and fourth sectional view of the example embodiment of the rotary pump 1 shown in FIG. 1. The third and fourth sectional views have been taken along the rotational axis D of the rotary pump 1. Unlike the third sectional view in FIG. 4, the sectional plane of the fourth sectional view (FIG. 5) has been rotated in the rotational direction of the delivery rotor 5 by a few degrees about the rotational axis D.

[0057] In the example embodiment of the rotary pump 1 shown, the pump housing 2 is embodied in two parts. The pump housing 2 comprises a housing cover 2b and a housing cup 2c. The housing cover 2b comprises a first end face 2a, and the housing cup 2c comprises a second end face 2a opposite the first end face 2a. The delivery rotor 5 is arranged axially between the two end faces 2a. The housing cup 2c comprises the fluid port 3a of the low-pressure inlet 3. The flow channeling structure 10 is also embodied completely within the housing cup 2c. The second end face 2a of the housing cup 2c defines an imaginary plane (not shown in the figures) which extends orthogonally with respect to the rotational axis D.

[0058] As shown in FIGS. 4 and 5, the flow channeling structure 10 comprises a first portion 15 which radially overlaps with the delivery region 6, in particular the low-pressure region 6a. The axial end wall 13 exhibits an orthogonal distance from the imaginary plane, wherein said distance is at least partially constant in the first portion. Irrespective of this, the axial end wall 13 transitions into the second end face 2a in the first portion 15, in particular in the region of the outer circumference of the second end face 2a.

[0059] The flow channeling structure 10 comprises a second portion 16. The second portion 16 adjoins the first portion 15 in the radial direction, radially outwards in relation to the rotational axis D. In other words, the second portion 16 is arranged directly next to the first portion 15 counter to the flow direction. The second portion 16 does not radially overlap with the delivery region 6. Irrespective of this, the second portion 16 comprises the incident flow edge 14. The orthogonal distance between the axial end wall 13 and the imaginary plane varies in the second portion 16. In the region of the incident flow edge 14, the axial end wall 13 exhibits a maximum orthogonal distance from the imaginary plane. The orthogonal distance between the axial end wall 13 and the imaginary plane decreases in the flow direction and/or radially inwards from the radially outer side. In the second portion 16, the axial end wall 13 exhibits a concave surface shape in relation to the imaginary plane.

[0060] As can be seen in FIG. 5, the free upper side of the flow channeling structure 10, i.e. the end face 13, forms a ramp 18 which rises towards the setting element 20. The ramp 18 can in particular be formed in the region of the portion 16. Fluid flowing over the ramp 18 is provided with an axial direction component by the ramp 18, such that it also flows with an axial direction component in an elongation of the ramp 18 into the delivery cells 7 passing through the low-pressure region 6a.

[0061] FIG. 6 shows a detail of a side view of the example embodiment of the rotary pump 1 shown in FIG. 1. FIG. 6 offers the observer a perspective view into the fluid port 3a of the low-pressure inlet 3, wherein the second portion 16 of the flow channeling structure 10 is particular easy to see. With regard to the specific configuration of the flow channeling structure 10, reference is made to the statements above.

TABLE-US-00001 Reference signs:  1 rotary pump  2 pump housing  2a end face  2b housing cover  2c housing cup  3 low-pressure inlet  3a fluid port  3b first inlet sub-channel  3c second inlet sub-channel  4 high-pressure outlet  5 delivery rotor  5a delivery means  5b rotor base body  5c outer surface area of the rotor base body  6 delivery region  6a low-pressure region  6b high-pressure region  7 delivery cells  8 restoring means  9 — 10 flow channeling structure 11 first side wall 12 second side wall 13 axial end wall 14 incident flow edge 15 first portion 16 second portion 17 mean line 18 ramp 19 — 20 setting element 21 inner surface area of the setting element 22 pressure channel 23 pressure chamber D rotational axis of the delivery rotor