Reduced-noise rotary pump

Abstract

A rotary pump, preferably a vane cell pump or a pendulum slider pump, includes a stator and a rotor which rotates about a rotational axis within the stator. The rotor includes multiple delivery elements which move radially in relation to the rotational axis, and two adjacent delivery elements limit a delivery cell together with the outer surface area of the rotor and the inner surface area of the stator. At least two delivery cells, preferably two adjacent delivery cells, exhibiting a first maximum cell volume form a first delivery cell group and at least two other delivery cells, preferably two other adjacent delivery cells, exhibiting a second maximum cell volume form a second delivery cell group. The first maximum cell volume of the delivery cells of the first delivery cell group is larger than the second maximum cell volume of the delivery cells of the second delivery cell group.

Claims

1. A rotary pump comprising: (a) a stator and (b) a rotor rotatable about a rotational axis within the stator, wherein (c) the rotor comprises multiple delivery elements adapted to move radially in relation to the rotational axis, and (d) two adjacent delivery elements limit a delivery cell together with an outer surface area of the rotor and an inner surface area of the stator, wherein (e) at least two delivery cells, which exhibit a first maximum cell volume form a first delivery cell group and (f) at least two other delivery cells, which exhibit a second maximum cell volume form a second delivery cell group, wherein (g) the first maximum cell volume of the delivery cells of the first delivery cell group is larger than the second maximum cell volume of the delivery cells of the second delivery cell group, and (h) wherein the delivery elements which limit a delivery cell of the first delivery cell group are each arranged at a first angular distance from each other on the rotor, and the delivery elements which limit a delivery cell of the second delivery cell group are each arranged at a second angular distance from each other on the rotor, wherein the first angular distance is larger than the second angular distance.

2. The rotary pump according to claim 1, wherein the delivery cells of the first delivery cell group exhibit an at least an identical first maximum cell volume, and the delivery cells of the second delivery cell group exhibit an identical second maximum cell volume.

3. The rotary pump according to claim 1, wherein a number of delivery cells in the first delivery cell group is not equal to a number of delivery cells in the second delivery cell group.

4. The rotary pump according to claim 1, wherein a number of delivery cells in the first delivery cell group is smaller than a number of delivery cells of the second delivery cell group.

5. The rotary pump according to claim 1, wherein the first delivery cell group comprises at least two and at most six delivery cells, wherein the adjacent delivery elements of the first delivery cell group are arranged at the first angular distance of 40° to 45° from each other on the rotor.

6. The rotary pump according to claim 1, wherein the second delivery cell group comprises at least four and at most ten delivery cells, wherein the adjacent delivery elements of the second delivery cell group are arranged at the second angular distance of 35° to 40° from each other on the rotor.

7. The rotary pump according to claim 1, wherein the rotary pump comprises a total of at least six and at most sixteen delivery cells.

8. The rotary pump according to claim 1, wherein a circumferential distance along the inner surface area of the stator between two adjacent delivery elements which limit a delivery cell of the first delivery cell group is larger than a circumferential distance along the inner surface area of the stator between two adjacent delivery elements which limit a delivery cell of the second delivery cell group.

9. The rotary pump according to claim 1, wherein a circumferential distance along the outer surface area of the rotor between two adjacent delivery elements which limit a delivery cell of the first delivery cell group is larger than a circumferential distance along the outer surface area of the rotor between two adjacent delivery elements which limit a delivery cell of the second delivery cell group.

10. The rotary pump according to claim 1, wherein the rotary pump comprises more than two delivery cell groups.

11. The rotary pump according to claim 10, wherein a maximum cell volume of the delivery cells of each delivery cell group is not equal to a maximum cell volumes of the delivery cells of each of the other delivery cell groups.

12. The rotary pump according to claim 10, wherein the delivery cells of two non-adjacent delivery cell groups exhibit an identical maximum cell volume.

13. The rotary pump according to claim 1, wherein the pump is a vane cell pump or a pendulum slider pump.

14. The rotary pump according to claim 1, wherein the at least two delivery cells which exhibit the first maximum cell volume and form the first delivery cell group are adjacent delivery cells or the at least two other delivery cells which exhibit the second maximum cell volume and form the second delivery cell group are adjacent delivery cells.

15. A rotary pump comprising: (a) a stator and (b) a rotor rotatable about a rotational axis within the stator, wherein (c) the rotor comprises multiple delivery elements adapted to move radially in relation to the rotational axis, and (d) two adjacent delivery elements limit a delivery cell together with an outer surface area of the rotor and an inner surface area of the stator, wherein (e) at least two delivery cells, which exhibit a first maximum cell volume form a first delivery cell group, and (f) at least two other delivery cells, which exhibit a second maximum cell volume form a second delivery cell group, wherein (g) the first maximum cell volume of the delivery cells of the first delivery cell group is larger than the second maximum cell volume of the delivery cells of the second delivery cell group, and (h) wherein the first delivery cell group comprises at least two and at most six delivery cells, wherein the adjacent delivery elements of the first delivery cell group are arranged at a first angular distance of 43° from each other on the rotor.

16. The rotary pump according to claim 15, wherein the second delivery cell group comprises at least four and at most ten delivery cells, wherein the adjacent delivery elements of the second delivery cell group are arranged at a second angular distance of 35° to 40° from each other on the rotor.

17. The rotary pump according to claim 15, wherein the rotary pump comprises a total of at least six and at most sixteen delivery cells.

18. A rotary pump comprising: (a) a stator and (b) a rotor rotatable about a rotational axis within the stator, wherein (c) the rotor comprises multiple delivery elements adapted to move radially in relation to the rotational axis, and (d) two adjacent delivery elements limit a delivery cell together with an outer surface area of a rotor and the inner surface area of the stator, wherein (e) at least two delivery cells which exhibit a first maximum cell volume form a first delivery cell group and (f) at least two other delivery cells which exhibit a second maximum cell volume form a second delivery cell group, wherein (g) the first maximum cell volume of the delivery cells of the first delivery cell group is larger than the second maximum cell volume of the delivery cells of the second delivery cell group, and (h) wherein the second delivery cell group comprises at least four and at most ten delivery cells, wherein the adjacent delivery elements of the second delivery cell group are arranged at a second angular distance of 38.5° from each other on the rotor.

19. The rotary pump according to claim 18, wherein the rotary pump comprises a total of at least six and at most sixteen delivery cells.

20. A rotary pump comprising: (a) a stator and (b) a rotor rotatable about a rotational axis within the stator, wherein (c) the rotor comprises multiple delivery elements adapted to move radially in relation to the rotational axis, and (d) two adjacent delivery elements limit a delivery cell together with an outer surface area of a rotor and the inner surface area of the stator, wherein (e) at least two delivery cells which exhibit a first maximum cell volume form a first delivery cell group and (f) at least two other delivery cells which exhibit a second maximum cell volume form a second delivery cell group, wherein (g) the first maximum cell volume of the delivery cells of the first delivery cell group is larger than the second maximum cell volume of the delivery cells of the second delivery cell group, and (h) wherein the rotary pump comprises a total of at least six and no more than sixteen delivery cells.

21. The rotary pump according to claim 20, wherein the at least two delivery cells which exhibit the first maximum cell volume and form the first delivery cell group are adjacent delivery cells or the at least two other delivery cells which exhibit the second maximum cell volume and form the second delivery cell group are adjacent delivery cells.

22. The rotary pump according to claim 20, wherein the rotary pump comprises a exactly nine delivery cells.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Different example features of aspects of the invention can be combined in accordance with the invention, wherever technically expediently and suitable. Other features and advantages of aspects of the invention follow from the following description of example embodiments on the basis of the figures. The figures show:

(2) FIG. 1 a schematic sectional representation of a first example embodiment of the rotary pump in accordance with the invention;

(3) FIG. 2 a second schematic sectional representation of the first example embodiment of the rotary pump in accordance with the invention;

(4) FIG. 3 a third schematic sectional representation of the first example embodiment of the rotary pump in accordance with the invention;

(5) FIG. 4 a sectional representation of a second example embodiment of the rotary pump in accordance with the invention.

(6) FIG. 5 illustrates a conventional pendulum slider pump.

DETAILED DESCRIPTION OF THE INVENTION

(7) FIG. 1 shows a schematic sectional representation of a first example embodiment of the rotary pump 1. In the first example embodiment, the rotary pump 1 is embodied as a vane cell pump 1 which comprises a stator 2 featuring a circular-cylindrical hollow space.

(8) A rotor 3 which can rotate about a rotational axis D is arranged within the circular-cylindrical hollow space of the stator 2. The outer diameter of the rotor 3 is smaller than the inner diameter of the circular-cylindrical hollow space of the stator 2, such that the outer surface area of the rotor 3 is spaced from the inner surface area of the stator 2. The rotational axis D preferably also forms the center axis of the rotor 3. In the example embodiment shown, the rotor 3 is arranged eccentrically with respect to the stator 2.

(9) As shown in FIG. 1, the rotor 3 comprises multiple delivery elements 4 which are distributed over the circumference of the rotor 3. The delivery elements 4 project radially from the rotor 3 in relation to the rotational axis D and are attached to or arranged on the rotor 3 such that they can move in a radial direction. A radial movement of the delivery elements 4, pointing outwards away from the rotational axis D, is limited by the inner surface area of the stator 2.

(10) Together with the inner surface area of the stator 2 and the outer surface area of the rotor 3, each two adjacent delivery elements 4 limit a delivery cell 11 to 13, 21 to 24. The example embodiment shown in FIG. 1 comprises a total of seven delivery cells 11 to 13, 21 to 24. Due to the eccentricity of the rotor 3 relative to the stator 2, each delivery cell 11 to 13, 21 to 24 exhibits a maximum cell volume. In the vane cell pump 1 depicted in FIG. 1, for example, each delivery cell 11 to 13, 21 to 24 reaches its maximum cell volume when it is in the “12 o'clock” position, due to the rotational movement of the rotor 3. Consequently, when the vane cell pump 1 is in the state depicted in FIG. 1, the delivery cell 12 has reached its maximum cell volume.

(11) The three adjacent delivery cells 11 to 13 exhibit an identical first maximum cell volume at the “12 o'clock” position and together form a first delivery cell group 10. The four adjacent delivery cells 21 to 24 exhibit an identical second maximum cell volume at the “12 o'clock” position and together form a second delivery cell group 20. The first maximum cell volume of the delivery cells 11 to 13 is larger than the second maximum cell volume of the delivery cells 21 to 24.

(12) The region between the outer surface area of the rotor 3 and the inner surface area of the stator 2 on the right-hand side half of the vane cell pump 1 depicted in FIG. 1 forms a suction region when the rotor 3 rotates anti-clockwise. Within the suction region, the cell volumes of the delivery cells 11 to 13, 21 to 24 increase in size from a minimum cell volume at the “6 o'clock” position to the maximum cell volume at the “12 o'clock” position. In advantageous embodiments of the vane cell pump 1, the suction region is connected to a suction port (not shown) for the delivery medium, such that the delivery medium is suctioned via the suction port by the increase in the delivery volumes of the individual delivery cell 11 to 13, 21 to 24.

(13) The region between the outer surface area of the rotor 3 and the inner surface area of the stator 2 on the left-hand side half of the vane cell pump 1 depicted in FIG. 1 forms a pressure region when the rotor 3 rotates anti-clockwise. Within the pressure region, the cell volumes of the delivery cells 11 to 13, 21 to 24 decrease in size from a maximum cell volume at the “12 o'clock” position to the minimum cell volume at the “6 o'clock” position. In advantageous embodiments of the vane cell pump 1, the pressure region is connected to a pressure port (pressure outlet, not shown) for the delivery medium, such that the delivery medium is pumped away via the pressure port (pressure outlet) by the decrease in the delivery volumes of the individual delivery cell 11 to 13, 21 to 24.

(14) Because the delivery cells 11 to 13, 21 to 24 are advantageously embodied and grouped into two delivery cell groups, the pressure pulses of the delivery medium at the pressure port (pressure outlet) are influenced in such a way that the excitation vibrations resulting from the pressure pulses are reduced. This in turn minimizes the noise emitted by the vane cell pump 1.

(15) FIG. 2 shows another schematic sectional representation of the first example embodiment of the rotary pump 1, wherein the angular distances α, β of the individual delivery elements 4 from each other are indicated. The delivery elements 4 which limit the delivery cells 11 to 13 of the first delivery cell group 10 are arranged at a first angular distance α from each other on the rotor 3. The delivery elements 4 which limit the delivery cells 21 to 24 of the second delivery cell group 20 are arranged at a second angular distance β from each other on the rotor 3, wherein the first angular distance α is larger than the second angular distance β. This means that the respective first maximum cell volume of the delivery cells 11 to 13 of the first delivery cell group 10 is larger than the respective second maximum cell volume of the delivery cells 21 to 24 of the second delivery cell group 20.

(16) FIG. 2 also shows a circumferential distance U.sub.I which extends between two adjacent delivery elements 4 along the inner surface area of the stator 2. A circumferential distance U.sub.A extends between two adjacent delivery elements 4 along the outer surface area of the rotor 3. In the example embodiment of the rotary pump 1 shown in FIG. 2, both the circumferential distance U.sub.I and the circumferential distance U.sub.A between the delivery cells 11 to 13 of the first delivery cell group 10 is larger than the circumferential distances U.sub.I, U.sub.A between the delivery cells 21 to 24 of the second delivery cell group 20. In particular in an embodiment of the rotary pump 1 (not shown) in which the delivery elements 4 are arranged at a constant angular distance on the rotor 3 but do not perpendicularly project radially outwards from the outer surface area of the rotor 3, the maximum cell volume of the delivery cells 11 to 13 of the first delivery cell group 10 can differ in relation to the maximum cell volume of the delivery cells 21 to 24 of the second delivery cell group 20 due to a different circumferential distance U.sub.I and/or a different circumferential distance U.sub.A.

(17) FIG. 3 shows the example embodiment of the rotary pump 1 depicted in FIG. 1, wherein the rotational axis D of the rotor 2 and the center axis M of the stator 2 are shown. The rotational axis D is offset from the center axis M, such that the rotor 3 is arranged eccentrically with respect to the stator 2. This eccentricity means that when the rotor 3 rotates anti-clockwise, the region between the outer surface area of the rotor 3 and the inner surface area of the stator 2 on the right-hand side half of the rotary pump 1 forms a suction region. Conversely, the region between the outer surface area of the rotor 3 and the inner surface area of the stator 2 on the left-hand side half of the rotary pump 1 forms a pressure region.

(18) In a development of the example embodiment of the rotary pump 1 shown in FIG. 3, the eccentricity of the rotor 3 relative to the stator 2 can be embodied to be variable. The position of the stator 2 relative to the rotor 3 could for example be varied in such a way that the center axis M coincides with the rotational axis D in a second position of the stator 2. As a result, the distance between the outer surface area of the rotor 3 and the inner surface area of the stator 2 remains constant over the entire circumference. When in operation, the rotary pump 1 would exhibit a so-called zero throughput in the second position of the stator 2, in which the delivery rate of the rotary pump 1 would be significantly reduced or eliminated. Ultimately, the delivery rate of the rotary pump can be controlled via the eccentricity of the stator 2 relative to the rotor 3.

(19) FIG. 4 shows a sectional representation of a second example embodiment of a rotary pump 1. In the second example embodiment, the rotary pump 1 is again embodied as a vane cell pump 1. In the second example embodiment, the vane cell pump 1 comprises a total of nine delivery cells 11 to 13, 21 to 26. The first delivery cell group 10 is formed by the adjacent delivery cells 11 to 13, wherein the adjacent delivery cells 11 to 13 are limited by delivery elements 4 which are arranged at a first angular distance α (not shown) of 43° from each other on the rotor 3. The second delivery cell group 20 is formed by the adjacent delivery cells 21 to 26, wherein the adjacent delivery cells 21 to 26 are limited by delivery elements 4 which are arranged at a second angular distance β (not shown) of 38.5° from each other on the rotor 3.

(20) FIG. 5 illustrates a rotor 3 of a well-known pendulum slider pump and a part of the stator 2. A delivery element 4 serving as a pendulum, which is moveably fixed at the stator 2 and extends into a slot of the rotor 3. The rotor 3 comprises a plurality of slots and a plurality of lands between two adjacent slots. The pump comprises further delivery elements each moveably fixed at the stator 2 and extending in one of the slots of the rotor 3 like the delivery element 4 shown in the figure. The lands of the rotor 3 form an outer surface area of the rotor 3. The stator 2 comprises an inner surface area that surrounds the outer surface area of the rotor 3. Each two adjacent delivery elements 4 limit a delivery cell together with the outer surface area of the rotor 3 and the inner surface area of the stator 2.

LIST OF REFERENCE SIGNS

(21) 1 vane pump 2 stator 3 rotor 4 delivery elements 10 first delivery cell group 11 delivery cell 12 delivery cell 13 delivery cell 20 second delivery cell group 21 delivery cell 22 delivery cell 23 delivery cell 24 delivery cell 25 delivery cell 26 delivery cell α first angular distance β second angular distance D rotational axis of the rotor M center axis of the stator U.sub.I circumferential distance along the inner surface area of the stator U.sub.A circumferential distance along the outer surface area of the rotor