CN117203405A

CN117203405A - Pump assembly, in particular for an adjustable chassis system

Info

Publication number: CN117203405A
Application number: CN202280030587.3A
Authority: CN
Inventors: J·伦
Original assignee: ZF Friedrichshafen AG
Current assignee: ZF Friedrichshafen AG
Priority date: 2021-05-11
Filing date: 2022-05-05
Publication date: 2023-12-08
Also published as: DE102021204750A1; WO2022238237A1; EP4337846A1

Abstract

Pump assembly comprising a pump and a pump drive, and an annular reservoir at least partially enclosing the pump and the pump drive, wherein the reservoir comprises a hydraulic pressure medium volume and a gas volume spatially separated therefrom within a rigid reservoir housing, wherein the gas volume is accommodated in a flexible enclosure within the reservoir housing that is isolated from the pressure medium volume.

Description

Pump assembly, in particular for an adjustable chassis system

Technical Field

The present invention relates to a pump assembly according to the preamble of claim 1, in particular for an adjustable chassis system.

Background

DE 10 2015 208 785 A1 describes an adjustable chassis system with a pump assembly. The embodiment according to fig. 4 shows a pump assembly with an annular reservoir which encloses at least one longitudinal section of the pump assembly. The specific design of the pump assembly, in particular of the reservoir, is not the subject of DE 10 2015 208 785 A1.

A pump assembly with an annular reservoir is known from DE 10 2018 129 539 A1 as part of a steering module for a drive train. Here, too, the reservoir encloses at least a part of the pump assembly. The annular reservoir comprises an axially movable annular piston separating the gas space from the pressure medium space.

Disclosure of Invention

It is an object of the present invention to improve the design of an annular reservoir in a pump assembly.

This object is achieved by: the gas volume is accommodated in a flexible envelope within the reservoir housing, which is isolated from the pressure medium volume.

The use of a flexible enclosure significantly improves noise emissions. The column of air within the enclosure reduces the sound that the pump and pump driver propagate to the environment.

In order to reduce the mechanical load of the enclosure, the enclosure has an arcuate shape matching the cross section of the reservoir. The encapsulation is supported at least in sections on the wall of the reservoir housing.

Alternatively, a plurality of encapsulants may be disposed in the memory. The size of the pressure medium volume or the pressure characteristic line can be determined by a plurality of encapsulation bodies with a constant memory size.

According to an advantageous subclaims, the enclosure has a filling coupling which passes through the wall of the reservoir housing. The filling of the envelope can thus also take place only when needed during assembly.

Furthermore, it can be provided that the filling connection of the at least one encapsulation and the filling connection for the pressure medium are arranged in a common area of the reservoir housing. This feature is particularly advantageous in a small installation space where two coupling parts can be arranged directly concurrently.

If desired, the filling connection can also have a fuse in order to provide a controlled gas extraction in the event of a fire, for example, so that the reservoir is not overloaded with pressure.

Optionally, at least two reservoirs can also be arranged axially stacked and have contact surfaces facing each other for a hydraulic connection coupling between the at least two reservoirs. At this point, standard memory may be used and then quantitatively increased to the desired memory volume by stacking arrangements.

Alternatively, at least two reservoirs may also be arranged concentrically with respect to one another, wherein the outer circumferential surface of the reservoir housing of the inner reservoir forms the inner circumferential surface of the outer reservoir housing.

Drawings

The invention is further elucidated by means of the following description of the drawings. Wherein:

FIG. 1 shows a schematic diagram of an application of a pump assembly;

FIG. 2 shows a cross-sectional illustration of a pump assembly;

FIG. 3 shows a pump assembly with axially stacked reservoirs;

FIG. 4 shows a pump assembly in which the reservoirs are arranged concentrically;

fig. 5 shows a memory with multiple encapsulants.

Detailed Description

Fig. 1 shows a schematic diagram of a combination of a pump assembly 1 and a shock absorber 3. The pump assembly 1 comprises a pump 5 and a pump driver 7. The invention is particularly suitable and expedient for use with pumps 5, such as gear pumps, having a non-uniform delivery rate. Particularly in pumps 5 with uneven delivery, noise emissions, for example, can occur which are carried into the passenger compartment.

The pump assembly 1 has an annular reservoir 9 which at least partially encloses the pump 5 and the pump drive 7. The pump 5 preferably has two conveying directions. Valves and other components of the hydraulic system are not shown. The reservoir 9 has a rigid reservoir housing 11 in which a hydraulic pressure medium volume 13 and a gas volume 15 spatially separated therefrom are accommodated. The gas volume 15 is accommodated in a flexible envelope 17 within the reservoir housing 11, which is isolated from the pressure medium volume 13. The envelope 17 floats in the pressure medium volume 13. Unlike the enclosed liquid, the sound transmission of the gas inside the enclosure 17 is significantly lower. Thus, the enclosure 17 has a sound insulating effect on the pump assembly 1.

As is also shown in fig. 5, the envelope 17 has an arc shape that matches the cross section of the reservoir 9 and is supported at least in places at the wall of the reservoir housing 11. The radial support of the enclosure 17 ensures a relatively low hydraulic load of the enclosure 17. A plurality of packages 17 can also be arranged in a memory, for example a standardized memory, which are introduced into the memory housing 11 as required.

The shock absorber 3 according to fig. 1 is based on a cylinder 19 in which a piston rod 21 carries out an axial displacement movement together with a piston 23 provided with a valve. The shock absorber 3 also has a reservoir 25 as a compensation space for the pressure medium displaced by the piston rod 21. The compensation space 25 is delimited radially by the cylinder 19 and the outer vessel 27. The piston rod guide 29 and the bottom 31 close the axial ends of the compensation space 25, which likewise contains the gas volume 15 and the pressure medium volume 13. An axially movable annular separating piston causes a spatial separation of the gas and the pressure medium. In principle, the structural design of the vibration damper 3 is subject to the application of the invention.

A hydraulic connection 35 is present between the pump assembly 1 and the shock absorber 3, so that by supplying pressure medium into the shock absorber 3 or out of the shock absorber 3 by means of the pump assembly 1, a greater or lesser push-out force can be generated on the piston rod.

Fig. 2 furthermore shows that the enclosure 17 has a filling connection 37 through the wall of the reservoir housing 11. The filling connection 37 of the at least one encapsulation 17 and the filling connection 39 for the pressure medium are preferably arranged in a common area of the reservoir housing 11. The preferred installation location for filling the coupling is the axial cover surface 41, since it is at least partially planar and can be sealed hydraulically in a correspondingly easy manner.

The filling connection 37 for the filling body 17 has a closing body 43, preferably made of plastic, which can also be embodied as a fuse in terms of its temperature characteristic. At a correspondingly high temperature, the closure 43 melts and the gas volume 15 can escape and the reservoir 9 loses its pressure preload at this point. Thus, no pressure cushion is available at this time, for example in the event of an accident and thus a damage to the reservoir 9, pressing the pressure medium out of the reservoir 9 and possibly ejecting the pressure medium out of the reservoir 9. The pressure medium in the liquid phase has little risk of combustion. The same medium as an oil cloud will ignite more easily.

The pump assembly 1 of fig. 3 shows that the combination of a plurality of reservoirs 9A, 9B is much simpler than a reservoir with axially movable separate pistons due to the use of an enclosure 17. At this point, at least two reservoirs 9A, 9B may be arranged axially stacked and the contact surfaces 45, 47 facing each other have an axial hydraulic connection coupling 49 between the at least two reservoirs 9A. The two reservoirs 9A, 9B can be filled via filling connections 37, 39. For conventional memories, external connection lines must be used to bridge the gas space.

Fig. 4 shows an alternative variant of the pump assembly 1, in which at least two reservoirs 9A, 9B are arranged concentrically to one another. At this time, the outer peripheral surface 51 of the reservoir housing 53 and the inner peripheral surface 55 of the outer reservoir housing 57 of the inner reservoir 9A form the second reservoir 9B. At this time, simple tubular bodies having different diameters may be used, which form a partition wall between the respective reservoirs 9A, 9B. For a reservoir with a suspended separating piston, this embodiment is not possible, since the cylinder is sized according to the inner or outer diameter, and only the sized diameter is suitable as a guide rail for the separating piston. For example, a radial connection 49 can be provided between the two reservoirs 9A, 9B.

List of reference numerals

1. Pump assembly

3. Vibration damper

5. Pump with a pump body

7. Pump drive

9. Memory device

9A memory

9B memory

11. Memory shell

13. Volume of pressure medium

15. Volume of gas

17. Encapsulated body

19. Cylinder body

21. Piston rod

23. Piston

25. Memory device

27. Container tube

29. Piston rod guide

31. Bottom part

33. Separating piston

35. Connection circuit

37. Filling connection part

39. Filling connection part

41. Cover surface

43. Closing body

45. Contact surface

47. Contact surface

49. Connection joint

51. Peripheral surface

53. Memory shell

55. Peripheral surface

57. A memory housing.

Claims

1. Pump assembly (1) comprising a pump (5) and a pump drive (7) and an annular reservoir (9; 9A; 9B) which at least partially encloses the pump (5) and the pump drive (7), wherein the reservoir (9; 9A; 9B) comprises a hydraulic pressure medium volume (13) and a spatially separated gas volume (15) from it in a rigid reservoir housing (11), characterized in that the gas volume (15) is accommodated in a flexible enclosure (17) in the reservoir housing (11) which is isolated from the pressure medium volume (13).

2. Pump assembly according to claim 1, characterized in that the envelope body (17) has an arc shape matching the cross section of the reservoir housing (11) and is at least partially supported at the wall of the reservoir housing (11).

3. Pump assembly according to claim 1 or 2, characterized in that a plurality of envelopes (17) are arranged in the reservoir (9; 9a;9 b).

4. A pump assembly according to at least one of claims 1 to 3, characterized in that the enclosure (17) has a filling coupling (39) through a wall of the reservoir housing (11).

5. Pump assembly according to claim 4, characterized in that the filling connection (37) of the at least one enclosure (17) and the filling connection (39) for the pressure medium (13) are arranged in a common area (41) of the reservoir housing (11).

6. Pump assembly according to claim 4, characterized in that the filling coupling (37) has a fusing part (43).

7. Pump assembly according to at least one of claims 1 to 6, characterized in that at least two reservoirs (9 a;9 b) are arranged axially stacked and that the contact surfaces (45; 47) facing each other have a hydraulic connection coupling (49) between the at least two reservoirs (9 a;9 b).

8. Pump assembly according to at least one of claims 1 to 7, characterized in that at least two reservoirs (9A; 9B) are arranged concentrically to one another, wherein an outer circumferential surface (51) of a reservoir housing (53) of the inner reservoir (9A) forms an inner circumferential surface of the outer reservoir housing (9B).