Rotary pump with supporting pockets

Abstract

A rotary pump, including: a housing featuring a delivery space which includes an inlet for a fluid on a suction side of the rotary pump and an outlet for the fluid on a pressure side of the rotary pump; an inner rotor which is arranged in the delivery space; an outer rotor which is arranged in the delivery space and forms delivery cells with the inner rotor, wherein an outer circumferential wall of the outer rotor is mounted in a sliding manner on an inner circumferential wall of the delivery space, wherein the inner circumferential wall of the delivery space and/or the outer circumferential wall of the outer rotor comprises at least one pocket.

Claims

1. A rotary pump, comprising: a housing featuring a delivery space which comprises an inlet for a fluid on a suction side of the rotary pump and an outlet for the fluid on a pressure side of the rotary pump; an inner rotor which is arranged in the delivery space; an outer rotor which is arranged in the delivery space and forms delivery cells with the inner rotor, wherein an outer circumferential wall of the outer rotor is mounted in a sliding manner on an inner circumferential wall of the delivery space, wherein the inner circumferential wall of the delivery space and/or the outer circumferential wall of the outer rotor comprises at least one pocket, wherein an axial extension of the at least one pocket is smaller than an axial length of the outer rotor and the at least one pocket has only one closed axial end, and wherein the at least one pocket is separated from the inlet and the outlet for the fluid.

2. The rotary pump according to claim 1, wherein the at least one pocket is open on an axial end facing a lid or a bottom which delimits the delivery space axially.

3. The rotary pump according to claim 1, wherein the housing comprises a cup-shaped housing part forming the inner circumferential wall and a bottom of the delivery space of the rotary pump, and wherein the at least one pocket is formed in the inner circumferential wall of the cup-shaped housing part.

4. The rotary pump according to claim 1, wherein the at least one pocket comprises a plurality of pockets.

5. The rotary pump according to claim 1, wherein the at least one pocket is formed in the inner circumferential wall of the delivery space.

6. The rotary pump according to claim 1, wherein the one closed axial end is a closed axial front end.

7. The rotary pump according to claim 1, wherein the at least one pocket is arranged in an area radially outward from the outlet and/or the inlet.

8. The rotary pump according to claim 1, comprising an electric drive.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the following, aspect of the invention are described in more detail on the basis of figures. Features essential to aspects of the invention which can only be gathered from the figures form part of the scope of aspects of the invention and can advantageously develop the rotary pump in accordance with claim 1, alone or in combinations shown.

(2) The individual figures show:

(3) FIG. 1 a delivery space featuring a pocket in the inner circumferential wall of the delivery space in a central region of the outlet from the delivery space;

(4) FIG. 2 a delivery space featuring a pocket in the inner circumferential wall of the delivery space in the region of the inlet into the delivery space, and a connecting channel which connects the pocket to the inlet;

(5) FIG. 3 a delivery space with an inner rotor and outer rotor indicated, each featuring a pocket in the inner circumferential wall of the delivery space in the region of the inlet into the delivery space and in the region of the outlet from the delivery space, and a connecting channel which connects one of the pockets to the inlet, and another connecting channel which connects the other of the pockets to the outlet;

(6) FIG. 4 a delivery space featuring a pocket in the inner circumferential wall of the delivery space in the region of each of the sealing stay and the driving stay;

(7) FIG. 5 a delivery space featuring a pocket in the inner circumferential wall of the delivery space in a region of the outlet from the delivery space which is offset in or counter to a rotational direction of the rotary pump;

(8) FIG. 6 a delivery space featuring a pocket in the inner circumferential wall of the delivery space in the region of each of the inlet into the delivery space and the outlet from the delivery space;

(9) FIG. 7 a delivery space featuring three pockets in the inner circumferential wall of the delivery space, in a plan view and a perspective view featuring the inner rotor and outer rotor;

(10) FIG. 8 a delivery space featuring a pocket in the inner circumferential wall of the delivery space in a central region of the inlet into the delivery space;

(11) FIG. 9 a delivery space with an inner rotor and outer rotor indicated, each featuring a pocket in the inner circumferential wall of the delivery space in the region of the sealing stay and the driving stay, and a connection in the region of the driving stay which connects the pocket to a delivery cell of the rotary pump;

(12) FIG. 10 a delivery space with an inner rotor and outer rotor indicated, each featuring a pocket in the inner circumferential wall of the delivery space in the region of the sealing stay and the driving stay, as well as a connection in the region of the driving stay and a connection in the region of the sealing stay;

(13) FIG. 11 a delivery space featuring a pocket that extends from an inlet to an outlet; and

(14) FIG. 12 a delivery space featuring a pocket that extends from a sealing stay to a driving stay.

DETAILED DESCRIPTION OF THE INVENTION

(15) FIG. 1 shows a view from above into a delivery space 1 of a rotary pump. Of the rotary pump, a part of the housing 2 can be seen, together with the base 3 of the delivery space 1. An opening 4 is formed eccentrically in the base 3, through which a drive axle for the inner rotor 9, shown only in FIGS. 3, 7, 9 and 10, can for example be guided into the interior of the delivery space 1.

(16) An inlet 5 for a fluid into the delivery space 1, and an outlet 6 for the fluid from the delivery space 1, are also formed in the base 3. The numbering applies to a rotary pump featuring an inner rotor 9 which rotates anti-clockwise. If the rotational direction is reversed, the inlet 5 correspondingly comes to form the outlet 6, and the outlet 6 becomes the inlet 5.

(17) The housing 2 forms an inner circumferential surface 11 of the delivery space 1 which, together with an outer circumferential surface 12 of the outer rotor 10 which is likewise shown only in FIGS. 3, 7, 9 and 10, forms a sealing gap 16 over large parts of the circumference, such that the inner circumferential surface 11 forms a guide or sliding surface for the outer rotor 10.

(18) A pocket 7, which extends radially outwards, is formed in the inner circumferential surface 11 in the region of the outlet 6. The pocket 7 is arranged centrally with respect to the outlet 6 as viewed in the circumferential direction. The outer circumferential surface 12 of the outer rotor 10 and the inner circumferential surface 11 of the delivery space 1 are clearly spaced from each other in the region of the pocket 7, such that the outer rotor 10 is not guided by the inner circumferential surface 11 in the region of the pocket 7. Fluid can pass into the pocket 7, for example via a leakage flow, from the outlet 6 and/or from at least one delivery cell 13 which is formed by the inner rotor 9 and outer rotor 10 and in which the fluid is transported from the inlet 5 to the outlet 6 and can be compressed and/or raised to a higher pressure level in the process.

(19) The fluid can for example be an oil which is pumped from a reservoir to a consumer. The fluid or oil which collects in the pocket 7 can then be used, when starting up the rotary pump, to ensure instant lubrication in the sealing gap between the inner circumferential wall 11 and the outer circumferential surface 12 of the outer rotor 10, such that the force necessary in order to start up the rotary pump can be reduced. The fluid accumulated in the pocket 7 can also have a damping effect and contribute to greater operational smoothness in the rotary pump, i.e. for example lower noise emissions, during operation of the rotary pump. Lastly, the fluid in the pocket 7 can prevent or at least delay wear on the outer circumferential surface 12 of the outer rotor 10 and on the inner circumferential surface 11 of the delivery space 1 and thus increase the operational service life of the rotary pump.

(20) In FIG. 2, the pocket 7 is formed in the region of the inlet 5 and connected to the inlet 5 via a connection 8 in the base 3. Fluid can flow from the inlet 5 into the pocket 7 via the connection 8 and fill the pocket 7 with the fluid to be pumped. The connection 8 is embodied as a groove in the base 3, wherein the groove is open towards the delivery space 1.

(21) FIG. 3 shows an embodiment of an aspect of the invention in which two pockets 7 are formed in the inner circumferential surface 11 of the delivery space 1. The inner rotor 9 and the outer rotor 10 are indicated in FIG. 3. A pocket 7 is formed in the region of each of the inlet 5 and outlet 6. Each of the pockets 7 is connected to the inlet 5 or, respectively, outlet 6 assigned to it via a connection 8. The two connections 8 shown or the pockets 7 can be fluidically connected to each other by another connection (not shown) which can for example be formed in the inner circumferential wall 11 or in the base 3.

(22) In FIG. 4, a pocket 7 is embodied in the inner circumferential wall 11 in the region of each of the driving stay 14 and the sealing stay 15. In FIG. 5, which substantially corresponds to FIG. 1, the one pocket 7 is not arranged centrally, but instead offset with respect to the outlet 6, as viewed in the circumferential direction. The pocket 7 of this embodiment can in particular be supplied and filled with fluid from delivery cells 13, shown only in FIGS. 3, 7, 9 and 10, passing over it and/or by a leakage flow.

(23) In the example embodiment of FIG. 6, the arrangement of the pockets 7 in the inner circumferential surface 11 corresponds to the arrangement as shown in FIG. 3. Unlike in FIG. 3, the pockets 7 are not connected to the inlet 5 or, respectively, the outlet 6 via a connection 8 in each case but are instead supplied with the fluid via a leakage flow and possibly via delivery cells 13 passing over them.

(24) FIG. 7 shows an example embodiment of a rotary pump in accordance with an aspect of the invention featuring three pockets 7 which are arranged in a substantially uniform distribution over the circumference of the delivery space 1 and therefore as viewed in in the circumferential direction. The pockets 7 can all be embodied identically, or each of the pockets 7 can exhibit a geometry and/or shape and/or size which is different to one of the other pockets 7.

(25) The housing 2 is shown together with the delivery space 1 in a perspective view. The outer rotor 10 is arranged in the delivery space 1, and an eccentrically mounted inner rotor 9 is arranged in the outer rotor 10. The inner rotor 9 and outer rotor 10 together form delivery cells 13 in which the fluid can be transported from the inlet 5 to the outlet 6, wherein the fluid pressure is increased and/or the fluid is compressed while bring transported. The inner rotor 9 or the outer rotor 10 can be connected to a rotary drive, wherein the driven inner rotor 9 or outer rotor 10 transmits the rotational movement onto the non-driven outer rotor 10 or inner rotor 9.

(26) The example embodiment of FIG. 8 substantially corresponds to that of FIG. 2. In FIG. 8, the pocket 7 is arranged centrally in the region of the inlet 5 as viewed in the circumferential direction. The pocket 7 lacks a direct connection to the inlet 5 and outlet 6. Alternatively, the rotary pump can comprise a connection which connects the pocket 7, which is arranged in the region of the inlet 5, to the outlet 6. The connection can extend in the base 3, the outer circumferential surface 12 and/or the inner circumferential surface 11.

(27) In FIG. 9, a pocket 7 is arranged in the region of each of the sealing stay 15 and driving stay 14. A connection 8 which is embodied in the driving stay 14 connects the pocket 7 to the delivery cell 13 which is respectively passing over the connection 8, such that the residual fluid from this delivery cell 13, which can be at a particularly high pressure (in particular a squeezing pressure), can flow into the pocket 7. This pressure relief on or in the driving stay 14 can be advantageous for operational smoothness in the inner rotor 9, since forces orthogonal to the rotary axis of the inner rotor 9 can thus be reduced.

(28) In FIG. 10, a pocket 7 is arranged in the region of each of the sealing stay 15 and driving stay 14. A connection 8 which is embodied in each of the driving stay 14 and sealing stay 15 connects the respective pocket 7 to the delivery cell 13 which is respectively passing over the connection 8.

(29) The person skilled in the art will recognize from the preceding description that other variations are also disclosed by aspects of the invention, such as for example supplying additional pockets 7, i.e. not only the pockets 7 shown in the figures, via connections 8. The person skilled in the art will also be aware from the description that two or more connections 8 can be connected to each other via one or more additional connections. Lastly, the person skilled in the art will recognize that the pockets 7 can also be supplied with fluid via feed conduits (not shown) which lead from outside the delivery space 1 directly into the pockets 7, for example from the suction region or pressure region of the rotary pump.

LIST OF REFERENCE SIGNS

(30) 1 delivery space 2 housing 3 base 4 opening 5 inlet 6 outlet 7 pocket 8 connection 9 inner rotor 10 outer rotor 11 inner circumferential wall 12 outer circumferential wall 13 delivery cell 14 driving stay 15 sealing stay 16 sealing gap