EP3737862A1

EP3737862A1 - Hydraulic machine, hydraulic assembly having the hydraulic machine, and hydraulic axle having the hydraulic machine

Info

Publication number: EP3737862A1
Application number: EP19700638.0A
Authority: EP
Inventors: Andreas Guender; Jan Lukas Bierod; Johannes Schwacke; Saskia Ryznar; Oleg Stefanjuk; Marco Scholz; Emil Hanauer; Rene HUETTL
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2018-01-11
Filing date: 2019-01-07
Publication date: 2020-11-18
Anticipated expiration: 2039-01-07
Also published as: DE102018200345A1; US11619214B2; CN111566346B; US20200340460A1; WO2019137862A1; CN111566346A; EP3737862B1

Abstract

A hydraulic machine (1) having a housing interior space (30) and having a group (16) of hydrostatic working chambers which are mounted in said housing interior space so as to be rotatable about an axis of rotation (18) and which, as the group rotates, are connectable alternately to a high pressure and to a low pressure of the hydraulic machine and exhibit leakage into the housing interior space, wherein a heat exchanger device (36) is accommodated in the housing interior space (30). A hydraulic assembly and a hydraulic axle, each having a hydraulic machine of said type, are also disclosed.

Description

Hydromachine, hydraulic aggregate with hydromachine, and hydraulic axis with hydromachine

description

The invention relates to a hydraulic machine according to the preamble of patent claim 1, a hydraulic unit with the hydraulic machine according to claim 11, as well as a hydraulic axis with the hydraulic machine according to claim 12.

The heart of a hydraulic circuit is a hydraulic machine, in particular a hydraulic pump. It converts mechanical into hydraulic, in particular hydrostatic, energy of a pressure medium conveyed by it. In the case of operation as a hydraulic motor, the conversion takes place in the reverse direction. In energy conversion occur losses that lead in the case of the hydraulic circuit in particular to the heating of the pressure medium. In this case, the loss occurring in the hydraulic machine (s) is responsible for the majority of the heating of the pressure medium, a much smaller part is caused by flow losses in lines. The heating of the pressure medium in the hydraulic pump is particularly great.

In conventional solutions, the heat loss incurred in the hydraulic pump due to loss of thermal energy is carried off by the pumped pressure medium into the hydraulic circuit until it is removed by means of an external heat exchanger as heat to a coolant. Here, the thermal energy is distributed to a large volume of oil, whereby a large amount of pressure medium is to circulate to dissipate the heat. Due to the large amount of pressure medium but also a DT to the recooling coolant is relatively small, so that the efficiency of the external heat exchanger is small and its heat exchange surface must be large, which keeps investment and operating costs high.

Page 1 of 15 The cooling can be done for example by an external tube bundle or plate heat exchanger. Coolant is, for example, water. By both

Heat exchangers are at risk of water entering the hydraulic oil as the oil and cooling water sides are only separated by a gasket in the case of the shell and tube heat exchanger, and only a thin solder layer in the case of the plate heat exchanger. Both seals can fail due to operational wear and so the

Operational safety of the hydraulic machine and the components and processes supplied by it are endangered by water entering the hydraulic oil.

The documents DE 94 11 163 Ul, JPH 08 22 64 12 and DE 27 03 686 each show a solution in which a cooling means of a flushing of a housing interior of the

Hydraulic pump with pressure medium. That way from the hydro pump

discharged pressure medium is recooled in a separate heat exchanger with water. Again, the circulating pressure medium amount is large. In addition, the flushed out amount must be permanently refilled, which brings device complexity with it.

The document CN 106 224 228 shows a hydraulic pump whose housing is wrapped by a heat pipe. The final dissipation of the heat takes place by recooling the medium of the heat pipe via a water bath. A disadvantage of this solution, for example, that the heat pipe through its external exposure to the

Hydraulic pump is exposed to damage due to impact.

A related solution is the document DE 10 2012 000 986 B3, in which a cooling jacket for a hydraulic pump is proposed. The disadvantage here is that such

Cooling jacket construction can take up comparatively much space.

On the other hand, the object of the invention is to provide a hydraulic machine with more efficient cooling, a hydraulic unit with the hydraulic machine and a hydraulic axis with the hydraulic machine.

The first object is achieved by a hydraulic machine with the features of

Patent claim 1, the second by a hydraulic unit with the features of

Page 2 of 15 Claim 11 and the last by a hydraulic axis with the features of claim 12th

Advantageous developments of the inventions are described in the respective dependent claims.

A hydraulic machine has a housing interior and a group of hydrostatic working spaces mounted rotatably about a rotation axis. These are connected in rotation of the group alternately with a high pressure and a low pressure of the hydraulic pump, in particular a corresponding port. During operation of the hydraulic machine, the pressure medium heats up. The work spaces have a leakage volume flow into the interior of the housing. According to the invention for cooling in

Housing interior accommodated a heat exchange device. In particular, this comes in contact with the leakage volume or volume flow.

The arrangement of the heat exchange device so close to the place of warming of the pressure medium, the DT is particularly high. Also, a turbulent turbulence of existing due to the leakage in the housing interior pressure medium due to the rotating work spaces is high. Already one of the two factors mentioned leads to an improved heat transfer, both together make the heat transfer particularly efficient. Therefore, a small and simply constructed heat exchange surface in the housing interior is sufficient. By receiving the heat exchange device in

Housing interior is realized a particularly efficient arrangement of the required cooling component.

Preferably, the hydrostatic working spaces are each bounded by a hydrostatic cylinder-piston unit of the hydraulic machine.

Preferably, the hydraulic machine is an axial piston machine and the cylinders are formed by cylinder bores formed in a rotatable cylinder drum. In which the pistons are arranged axially displaceable.

Preferably, the axial piston machine is formed in a swash plate design, wherein the piston mounted on a housing fixed or pivotally mounted

Page 3 of 15 Sliding disc are slidably supported. Alternatively, a Schrägachsenbauweise is possible, wherein the piston heads are rotatably connected to an employee employed to the axis of rotation drive shaft.

In a further development, the heat exchange device takes at least partially an annular space, which extends radially and axially between a Gehäuseinnenwandung and the group. The annulus offers itself particularly because it is present anyway and does not need to be extended or only slightly to arrange the heat exchange device. So the hydraulic machine builds despite the arranged inside the housing

Heat exchange device yet small.

In a development, the annular space extends in the direction of the axis of rotation and at least partially cylindrical. He may alternatively or additionally have a conical or oval section, for example, to promote a turbulent turbulence of the leakage volume or leakage volume flow and so the

Heat transfer even more efficient.

In a further development, the axis of rotation of the heat exchange device is annular, in particular annular, or polygonal, in particular four- or six- or octagonal, embraced. Said forms relate to a projection of a contour, in particular an outer and / or inner contour of the heat exchange device, in a plane whose normal is the axis of rotation.

Preferably, a wall of the heat exchange device is formed by a tube. In particular, at least its course in the housing interior, cross-section,

Wall thickness and / or material designed at least depending on the intended purpose to be transferred heat and / or the intended temperature of the pressure medium.

Preferably, in the heat exchange device, a fluid is arranged in a single-phase or two-phase, in particular arranged in a flowing manner.

A simple and inexpensive to be manufactured design of the heat exchange device is given if it extends in a development at least partially helical or helical around the axis of rotation. This results in a design corresponding,

Page 4 of 15 specific temperature profile along the helix on the side of the coolant and / or on the side of the housing interior.

In order to set a different specific temperature profile along the helix on the side of the coolant and / or on the side of the housing interior, in an alternative development, the heat exchange device extends at least in sections in an undulating manner around the axis of rotation and in the direction of the axis of rotation. In this case, sections which extend predominantly parallel to or in the direction of the axis of rotation alternate with sections which extend predominantly circumferentially around the axis of rotation.

In order to provide, in particular, a larger heat exchange surface, in a development, the heat exchange device extends in the direction radially to the axis of rotation with at least two windings or layers.

In a development that is easy to manufacture, a first winding or layer extends radially inward in a direction of the axis of rotation up to a vertex of the first winding or layer, where it is at least one pipe diameter by an amount

Heat exchange device guided radially outward and extends with a second winding or layer from the apex back in the opposite direction.

The heat exchange device may extend partially or fully around the axis of rotation, so that a space in the housing interior, in particular in the annulus claimed space of a component of the hydraulic machine is bypassed by the heat exchange device.

In one variant, the housing interior is delimited by a housing which is penetrated on the same side by a drive shaft which is rotatable about the rotation axis and to which the cylinder-piston units are connected in a rotationally fixed manner, and by an inlet and / or a return of the heat exchange device.

In one variant, the housing interior is delimited by a housing which has ports of high pressure and low pressure on the same side and is penetrated by an inlet and / or a return of the heat exchanger device.

Preferably, the inlet and / or the return is sealed on the outside of the housing against this. This makes the sealing point easily accessible, controllable and maintainable.

Page 5 of 15 A hydraulic unit has a hydraulic machine formed according to at least one aspect of the foregoing description. In this case, at least with the hydraulic machine, in particular with its housing, connected at least: a drive machine, in particular an electric machine, via which a torque to the hydraulic machine is transferable, and a pressure medium container, which is connectable to the low pressure and / or high pressure of the hydraulic machine. Depending on the configuration of a hydraulic circuit into which the hydraulic machine can be integrated, the pressure medium container can be designed as an open tank (open circuit) or pressure equalization tank (closed circuit).

Such an aggregate is provided, for example, for supplying pressure medium to a hydraulic cylinder.

A hydraulic axle accordingly has a hydraulic machine, which according to at least one aspect of the preceding description. It is firmly connected to the hydraulic machine, in particular with its housing, at least: a prime mover, in particular electric machine, via which a torque to the hydraulic machine is transferable, one of the hydraulic machine with pressure medium supplyable hydraulic cylinder and a

Control block, in particular valve control block, for controlling the pressure medium supply. In addition, as already mentioned above, a tank or a pressure medium container which can be connected to the low pressure and / or high pressure of the hydraulic machine can be provided.

Several embodiments of a hydraulic machine according to the invention and their

Heat exchange devices are shown in the drawings. With reference to the figures of these drawings, the invention will now be explained in more detail.

Show it:

1 shows a hydrostatic axial piston pump in swash plate construction according to a first embodiment, in a longitudinal section,

2 shows a hydrostatic axial piston pump in swash plate construction according to a second embodiment, in a longitudinal section,

Figure 3 shows a second embodiment of a heat exchange device of

Axial piston pump according to Figure 2 in a perspective view,

FIG. 4 shows the heat exchanger device according to FIG. 3 in a side view,

Page 6 of 15 FIG. 5 shows the heat exchanger device according to FIGS. 3 and 4 in a view in the direction of the longitudinal axis,

Figure 6 shows a third embodiment of a heat exchange device in one

perspective view,

FIG. 7 shows a hydrostatic axial piston pump according to a third exemplary embodiment with the heat exchange device according to FIG. 6,

FIG. 8 shows a hydrostatic axial piston pump according to a fourth exemplary embodiment in a longitudinal section,

Figure 9 shows a heat exchange device according to a fifth embodiment in a side view and a plan view, and

10 shows a heat exchange device according to a sixth embodiment in a side view and in a plan view.

According to FIG. 1, a first exemplary embodiment of a hydrostatic axial piston pump 1 has a housing 2 with an annular housing jacket 4, which is closed on the end, on the one hand, by a drive-through cover 6 and, on the other hand, by a connection cover 8.

In the housing 2, a drive shaft 14 is rotatably supported via roller bearings 10, 12. Rotatably connected to the drive shaft 14 is a cylinder drum 16, in which along a concentric with the axis of rotation 18 arranged pitch circle a plurality of cylinder bores is parallel to the axis of rotation 18 is introduced. In the respective cylinder bore, a hydrostatic working piston 20 is axially displaceably guided and slidably supported by the housing cover 6 on a swash plate 22 fixedly arranged in the housing 2. In the region of the connection cover 8, a control disk 24, which is penetrated by passage openings (not shown), is arranged between the cylinder drum 16 and the connection cover 8. The through-hole (pressure kidney) are in pressure medium connection with a high pressure port 26 and a low pressure port 28 of the

Connection cover 8.

Upon rotation of the drive shaft 14, and thus the cylinder drum 16, the hydrostatic working chambers are connected via their to the terminals 26, 28 facing outlets alternately with high and low pressure.

In the housing 2, a housing interior 30 is formed. Radial between the

Cylinder drum 16 and a Gehäuseinnenwandung 32, an annular space 34 is formed. In

Page 7 of 15 this and about the axis of rotation 18 extends a helical

Heat exchange device 36 for removing thermal energy from the housing 2. As described above, the hottest and most lossy point in a hydraulic circuit in the hydrostatic axial piston pump 1. The arranged in the annular space 34 heat exchange device 36, the thermal energy is exactly at this point to one in the coil flowing coolant, such as water, transferred. Thus, a DT at this point is very high and the heat transfer coefficient a also. This can be transferred to a small heat exchange surface, a large amount of heat. As a result, a significantly larger heat exchanger, which would have to be made available externally, is eliminated. In this way, both the investment costs and the operating costs savings can be achieved. In addition, direct temperature-related wear on the hydrostatic axial piston pump can be minimized since it can always be operated in the optimum temperature range.

Since the heat is transferred in this way in the "hottest place" of a hydrostatic circuit, the dissipated by the cooling water thermal energy can be well used, since their temperature level is particularly high above the

Ambient temperature is high. In this way, for example, a secondary hot water supply can be supplied with heat. This can be implemented, for example, by a 3-way circuit in which the cooling water in the

Heat exchange device 36 circulates until a sufficient DT is reached.

Due to the possible elimination of the external heat exchanger and the above-mentioned, based on the relatively vulnerable technology of the tube bundle heat exchanger or plate heat exchanger, error source omitted.

On a more detailed explanation of the basic structure and the basic operation of the hydrostatic axial piston machine 1 according to Figure 1, and the following embodiments, is omitted at this point, since this is well known in the prior art. The stated advantages also apply to the following exemplary embodiments.

FIG. 2 shows a hydrostatic axial piston pump 101 according to a second embodiment

Embodiment. A difference from the first embodiment according to FIG. 1 is

Page 8 of 15 in that the heat exchange device 136 differs from that according to FIG. Although it is also designed as a helix, but are the individual turns of the helix in the axial direction to each other. In addition, an inlet 38 and a return 40 of the heat exchanger device 136 are shown in FIG. Both 38, 40 pass through the housing cover 6 and are sealed on the outside (not shown) against the housing 2. Through the inlet 38 flows in the helix of the

Heat exchange device 136 cooling water and takes on its way through the coil to the return 40 of the turbulence in the housing interior 134 turbulent

Leakage oil heat up.

As with all embodiments, the turbulence generated by the cylinder drum 16 in the oil bath of the housing interior 30 proves to be advantageous for the

Heat transfer coefficient of the heat exchange device 136. Due to the closer arrangement of the helices of the heat exchange device 136 is a heat flux density, compared with the first embodiment of Figure 1, increased.

FIGS. 3 to 5 show the heat exchanger device 136 according to FIG. 2 in a perspective view, a side view and a plan view. The comparatively short inlet 38 extends parallel to the axis of rotation 18 and is at right angles, with respect to the

Rotary axis 18 in the circumferential direction, angled. In the following, the helix extends with mutually adjacent turns in the direction of the axis of rotation 18 and circumferentially around it, until at apex of the heat exchange device 136, the helix tube tangentially expires and again at right angles, parallel to the axis of rotation 18 and is returned as return 40.

FIG. 6 shows a third exemplary embodiment of a heat exchange device 236 which is based on the helical heat exchange device 36 according to FIG. In contrast to this, the heat exchange device 236 in the radial direction two layers or

Windings, rather than just one, up. Like the first embodiment 36, the individual turns in the direction of the axis of rotation 18 at a distance from each other. In this way, the turbulent oil bath in the housing interior 30 can also reach the spaces between the turns. Starting from an inlet 38, internal turns extend circumferentially and in the direction of the axis 18 with a constant coil diameter up to a vertex of the heat exchanger device 36

Page 9 of 15 the diameter of the winding is extended to a larger radius and the turns are circumferentially returned in the reverse direction along the axis of rotation 18 around this. This results in two windings or layers. The outer winding runs as return 40 again on the side of the inlet 38, parallel to this, from.

FIG. 7 shows a third exemplary embodiment of a hydrostatic axial piston pump 201, which differs from the second exemplary embodiment according to FIG. 2 essentially by the changed heat exchanger device 236 according to FIG.

A fourth embodiment of a hydrostatic according to the invention

Axial piston pump 301 is shown in FIG. 8. It differs from the exemplary embodiment according to FIG. 7 because of the modified heat exchange device 336. This is now designed to be undulating instead of helical. In this case, a ring of alternately parallel to the axis of rotation 18 extending and circumferentially angled sections are lined up so that the tube of the heat exchange device 336 alternately in

Circumferential direction extends about the axis of rotation 18. In this way, a temperature profile of the temperature difference DT deviating from the exemplary embodiments shown so far can be realized.

A quite similarly constructed embodiment of a heat exchange device 436 is shown in FIG. 9. The embodiment differs from FIG. 8

Heat exchange device 436 in that comparatively few undulating

Sections are provided.

A last exemplary embodiment of a heat exchange device 536 is shown in FIG. 10. It extends in a helical stepwise manner and also has a rectangular cross section of the helices. These extend in sections horizontally, that is, in a plane whose normal is the axis of rotation 18, and are connected to each other by sections against the planes respectively. In this way, results in a basically stepped and helically wound heat exchange device.

Disclosed is a hydraulic machine with a housing interior, in which an engine is arranged, via the mechanical energy in hydraulic energy, and / or vice versa, leakage-related is changed. It is in the housing interior a

Page 10 of 15 Heat exchange device arranged to dissipate a heat flow of the leakage at least in sections.

Disclosed are still a hydraulic unit and a hydraulic axis, each having the hydraulic machine.

Page 11 of 15 LIST OF REFERENCE NUMBERS

1; 101; 201; 301 hydrostatic axial piston pump 2 housing

4 housing jacket

6 housing cover

8 connection cover

10, 12 rolling bearings

14 drive shaft

16 cylinder drum

18 axis of rotation

20 working pistons

22 swash plate

24 control disk

26 high pressure connection

28 low pressure connection

30 housing interior

32 housing inner wall

34; 134; 234; 334 annulus

36; 136; 236; 336; 436; 536 heat exchange device

Page 12 of 15

Claims

claims

1. Hydromachine with a housing interior (30) and one inside it

Rotary axis (18) rotatably mounted group of hydrostatic working spaces, which are connected in rotation of the group alternately with a high pressure (26) and a low pressure (28) of the hydraulic machine and a leakage in the

Housing interior (30) inside, characterized in that in the housing interior (30) has a heat exchange means (36; 136; 236; 336; 436; 536) is added.

A hydraulic machine according to claim 1, wherein said heat exchange means (36; 136; 236;

336) at least in sections occupies an annular space (34; 134; 234; 334) which extends between a housing inner wall (32; 132; 232; 332) and the

Working space limiting, hydrostatic cylinder-piston units extends.

3. A hydraulic machine according to claim 2, wherein the annular space (32; 132; 232; 332) in

Direction of the axis of rotation (18) and to this, in particular predominantly cylindrical or conical or oval, extends.

4. Hydromachine according to one of claims 1 to 3, wherein the axis of rotation (18) of the

Heat exchange device (36; 136; 236; 336) annular, in particular

circular, or polygonal, in particular four- or six- or octagonal, is embraced.

A hydraulic machine as claimed in any one of the preceding claims, wherein a wall of the heat exchange means (36; 136; 236; 336; 436; 536) is formed by a tube.

6. Hydromachine according to one of the preceding claims, wherein in the

Heat exchange device (36; 136; 236; 336) a fluid is arranged single-phase or two-phase.

7. hydraulic machine according to one of the preceding claims, wherein the

Heat exchange device (36; 136; 236; 536) at least partially helically or helically around the axis of rotation (18)) and in the direction of the axis of rotation (18).

Page 13 of 15

8. hydraulic machine according to one of the preceding claims, wherein the

Heat exchange device (336, 436) at least partially ondulierend around the axis of rotation (18) and in the direction of the axis of rotation (18)

9. hydraulic machine according to one of the preceding claims, wherein the

Heat exchange device (236) in the direction radially to the axis of rotation (18) with at least two windings or layers extends.

10. hydraulic machine according to one of the preceding claims, with a

Housing housing bounding housing (2, 4, 6, 8), which on a same side (6) of a about the rotational axis (18) rotatable drive shaft (14), with which the cylinder-piston units rotates are connected, and of an inlet ( 38) and a return (40) of the heat exchange device (136; 336) is penetrated, or which has on a same side terminals of the high pressure and the low pressure and is penetrated by an inlet and a return of the heat exchange device.

11. Hydraulic unit with a hydraulic machine, according to one of

preceding claims is formed, wherein at least fixed to the hydraulic machine are: a drive machine, in particular electric machine, via which a torque is transferable to the hydraulic machine, and a

Pressure medium tank, with the low pressure and / or high pressure of

Hydromachine is connectable.

12. Hydraulic axle with a hydraulic machine, according to one of claims 1 to

11 is formed, which are at least firmly connected to the hydraulic machine: a prime mover, in particular electric machine, via which a torque to the hydraulic machine is transferable, one of the hydraulic machine with pressure medium supplyable hydraulic cylinder and a control block, in particular valve control block, for controlling the pressure medium supply.

Page 14 of 15