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

Abstract

A hydraulic machine includes a housing interior space and a group of hydrostatic working chambers which are mounted in said housing interior space so as to be rotatable about an axis of rotation 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. A heat exchanger device is accommodated in the housing interior space. The hydraulic machine may be associated with a hydraulic assembly and a hydraulic axle.

Claims

1. A hydraulic machine comprising: a housing interior; a group of hydrostatic working chambers mounted in the housing interior and configured for rotation about an axis of rotation, said working chambers configured such that, upon rotation of the group, said working chambers are connectable in an alternating manner to a high pressure connection of pressure medium of the hydraulic machine and to a low pressure connection of the pressure medium of the hydraulic machine; a plurality of pistons, each piston at least partially positioned within a corresponding working chamber of the group of hydrostatic working chambers; a swash plate operably connected to the plurality of pistons, wherein the pressure medium is located in a portion of the housing interior that includes the swash plate; and a heat exchanger device including a spiral tube portion located in at least the portion of the housing interior including the swash plate, the spiral tube portion defining an interior space that is isolated from the housing interior, such that the pressure medium is spaced apart from the interior space of the spiral tube portion, and the spiral tube portion defining an exterior tube surface that is in contact with the pressure medium.

2. The hydraulic machine as claimed in claim 1, wherein the spiral tube portion, at least in sections, is located in an annular chamber of the housing interior that is defined between a housing inner wall and hydrostatic cylinder/piston units bounding the working chambers.

3. The hydraulic machine as claimed in claim 2, wherein the annular chamber extends in a direction of the axis of rotation and around the axis of rotation.

4. The hydraulic machine as claimed in claim 1, wherein the spiral tube portion of the heat exchanger device surrounds the axis of rotation in one of an annular and a polygonal manner.

5. The hydraulic machine as claimed in claim 1, wherein: a fluid is arranged in a single phase or in two phases in the interior space of the spiral tube portion of the heat exchanger device, and the fluid is water.

6. The hydraulic machine as claimed in claim 1, wherein: the spiral tube portion is a first spiral tube portion, the heat exchanger device includes a second spiral tube portion located in the housing interior, the first and second spiral tube portions extend coaxially along the axis of rotation, and the first and second spiral tube portions overlap each other along the axis of rotation.

7. The hydraulic machine as claimed in claim 1, further comprising: a housing which defines the housing interior, the housing having a first side configured such that: a drive shaft which is rotatable about the axis of rotation and to which the swash plate and cylinder/piston units are connected for rotation therewith, and a feed and a return of the heat exchanger device pass through the first side; or connections of the high pressure and of the low pressure and the feed and the return of the heat exchanger device pass through the first side.

8. The hydraulic machine as claimed in claim 3, wherein the annular chamber extends around the axis of rotation predominantly in one of a cylindrical, a conical, and an oval manner.

9. The hydraulic machine as claimed in claim 1, wherein the spiral tube portion extends around the axis of rotation in one of a circular, a square, a hexagonal, and an octagonal manner.

10. The hydraulic machine as claimed in claim 1, wherein: the spiral tube portion includes a plurality of turns defining the spiral tube portion, and the turns are positioned against each other along the axis of rotation.

11. The hydraulic machine as claimed in claim 1, wherein: an exterior piston surface of each piston of the plurality of piston is located between the swash plate and the group of hydrostatic working chambers, and each of the exterior piston surfaces is located in the portion of the housing interior including the swash plate and is in contact with the pressure medium.

12. A hydraulic assembly comprising: a hydraulic machine comprising: a housing defining a housing interior; a group of hydrostatic working chambers mounted in the housing interior configured for rotation about an axis of rotation, said working chambers configured such that, upon rotation of the group, said working chambers are connectable in an alternating manner to a high pressure connection of pressure medium of the hydraulic machine and to a low pressure connection of pressure medium of the hydraulic machine; a plurality of pistons, each piston at least partially positioned within a corresponding working chamber of the group of hydrostatic working chambers; a swash plate operably connected to the plurality of pistons, wherein the pressure medium is located in a portion of the housing interior that includes the swash plate; and a heat exchanger device including a spiral tube portion located at least in the portion of the housing interior including the swash plate, the spiral tube portion defining an interior space that is isolated from the housing interior, such that the pressure medium is spaced apart from the interior space of the spiral tube portion, and the spiral tube portion defining an exterior tube surface that is in contact with the pressure medium; a drive machine fixedly connected to the hydraulic machine and configured to transmit a torque to the hydraulic machine; and a pressure medium container configured to contain the pressure medium, the pressure medium container fixedly connected to the hydraulic machine and configured to be connected to at least one of the low pressure connection and the high pressure connection.

13. The hydraulic assembly as claimed in claim 12, wherein the drive machine is an electric machine.

14. A hydraulic axle comprising: a hydraulic machine comprising: a housing defining a housing interior; a group of hydrostatic working chambers mounted in the housing interior and configured for rotation about an axis of rotation, said working chambers configured such that, upon rotation of the group, said working chambers are connectable in an alternating manner to a high pressure connection of pressure medium of the hydraulic machine and to a low pressure connection of the pressure medium of the hydraulic machine; a plurality of pistons, each piston at least partially positioned within a corresponding working chamber of the group of hydrostatic working chambers; a swash plate operably connected to the plurality of pistons, wherein the pressure medium is located in a portion of the housing interior that includes the swash plate; and a heat exchanger device including a spiral tube portion located at least in the portion of the housing interior including the swash plate, the spiral tube portion defining an interior space that is isolated from the housing interior, such that the pressure medium is spaced apart from the interior space of the spiral tube portion, and the spiral tube portion defining an exterior tube surface that is in contact with the pressure medium; a drive machine fixedly connected to the hydraulic machine and configured to transmit a torque to the hydraulic machine, a hydraulic cylinder fixedly connected to the hydraulic machine, the hydraulic machine configured to supply the pressure medium to the hydraulic cylinder; and a control block fixedly connected to the hydraulic machine and configured to control the supply of the pressure medium to the hydraulic cylinder.

15. The hydraulic axle as claimed in claim 14, wherein the drive machine is an electric machine and the control block is a valve control block.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) A number of exemplary embodiments of a hydraulic machine according to the disclosure and of the heat exchanger devices thereof are illustrated in the drawings. The disclosure will now be explained in more detail with reference to the figures of said drawings.

(2) In the drawings:

(3) FIG. 1 shows a hydrostatic axial piston pump in a swash plate type of construction according to a first exemplary embodiment, in a longitudinal section,

(4) FIG. 2 shows a hydrostatic axial piston pump in a swash plate type of construction according to a second exemplary embodiment, in a longitudinal section,

(5) FIG. 3 shows a second exemplary embodiment of a heat exchanger device of the axial piston pump according to FIG. 2 in a perspective view,

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

(7) FIG. 5 shows the heat exchanger device according to FIGS. 3 and 4 in a view in the direction of the longitudinal axis,

(8) FIG. 6 shows a third exemplary embodiment of a heat exchanger device in a perspective view,

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

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

(11) FIG. 9 shows a heat exchanger device according to a fifth exemplary embodiment in a side view and a top view, and

(12) FIG. 10 shows a heat exchanger device according to a sixth exemplary embodiment in a side view and in a top view.

DETAILED DESCRIPTION

(13) 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 one end side by a housing cover 6 and on the other end side by a connection cover 8. A drive shaft 14 is mounted rotatably in the housing 2 via rolling bearings 10, 12. A cylinder drum 16 into which a multiplicity of cylinder bores are introduced parallel to the axis of the rotation 18 along a partial circle arranged concentrically with respect to the axis of rotation 18 is connected to the drive shaft 14 for rotation therewith. A hydrostatic working piston 20 is guided in an axially displaceable manner in the respective cylinder bore and is supported in a sliding manner on the housing cover 6, on a swash plate 22 arranged fixedly in the housing 2. In the region of the connection cover 8, a control disk 24 through which passage clearances (not illustrated) pass is arranged between the cylinder drum 16 and the connection cover 8. The passage clearances (kidney-shaped pressure ports) are in pressure medium connection with a high pressure connection 26 and a low pressure connection 28 of the connection cover 8.

(14) When the drive shaft 14, and therefore the cylinder drum 16, are rotated, the hydrostatic working chambers 44 are connected via their openings facing the connections 26, 28 to the high pressure and low pressure in an alternating manner.

(15) A housing interior 30 is formed in the housing 2. An annular chamber 34 is formed radially between the cylinder drum 16 and a housing inner wall 32. A spiral heat exchanger device 36 for dissipating thermal energy from the housing 2 extends in said annular chamber and around the axis of rotation 18. As previously described, the point which is hottest and is most affected by losses is located in a hydraulic circuit in the hydrostatic axial piston pump 1. The heat exchanger device 36 arranged in the annular chamber 34 transmits the thermal energy precisely to said point using coolant, for example water, flowing in the spiral coil. As a result, a ΔT at this point is very high as is the heat transfer coefficient α. A large amount of heat can therefore be transmitted on a small heat exchange surface. As a result, a significantly larger heat exchanger which would have to be provided externally is dispensed with. A saving can thereby be obtained both on investment costs and operating costs. In addition, directly temperature-induced wear phenomena at the hydrostatic axial piston pump can be minimized since the latter can always be operated in the optimum temperature range.

(16) Since the heat is thereby transmitted to the “hottest location” of a hydrostatic circuit, the thermal energy which is dissipated by means of the cooling water can be readily used further since the temperature level of said thermal energy is particularly far above the ambient temperature. As a secondary measure, for example, a hot water supply can thereby be supplied with heat. This can be realized, for example, by a 3 way circuit in which the cooling water circulates in the heat exchanger device 36 until a sufficient ΔT is reached.

(17) The possible dispensing with the external heat exchanger also dispenses with the error source which has already been discussed further above and is based on the relatively vulnerable technology of the tubular heat exchanger or plate heat exchanger.

(18) A more detailed explanation of the basic construction and of the basic manner of operation of the hydrostatic axial piston machine 1 according to FIG. 1 and the following exemplary embodiments is omitted at this juncture since this is well known from the prior art. The advantages mentioned also apply to the following exemplary embodiments.

(19) FIG. 2 shows a hydrostatic axial piston pump 101 according to a second exemplary embodiment. One difference from the first exemplary embodiment according to FIG. 1 is that the heat exchanger device 136 differs from that according to FIG. 1. Although it is also configured as a spiral coil, the individual turns of the spiral coil lie against one another in the axial direction. In addition, a feed 38 and a return 40 of the heat exchanger device 136 are illustrated in FIG. 2. The two 38, 40 pass through the housing cover 6 and are sealed off from the housing 2 on the outer side of said cover (not illustrated). Cooling water flows in the spiral coil of the heat exchanger device 136 through the feed 38 and, on its way through the spiral coil to the return 40, absorbs heat from the leakage oil that is swirled turbulently in the housing interior 134.

(20) As in all of the exemplary embodiments, the turbulence generated in the oil bath of the housing interior 30 by the cylinder drum 16 proves advantageous for the heat transfer coefficient of the heat exchanger device 136. The closer arrangement of the spiral coils of the heat exchanger device 136 increases a heat flow density in comparison to the first exemplary embodiment according to FIG. 1.

(21) FIGS. 3 to 5 show the heat exchanger device 136 according to FIG. 2 in a perspective view, a side view and a top view. The comparatively short feed 38 extends parallel to the axis of rotation 18 and is bent at a right angle in the circumferential direction with respect to the axis of rotation 18. The spiral coil subsequently runs with turns lying against one another in the direction of the axis of rotation 18 and circumferentially around the latter until, at an apex of the heat exchanger device 136, the spiral tube peters out tangentially and is bent again at a right angle parallel to the axis of rotation 18 and is guided back as the return 40.

(22) FIG. 6 shows a third exemplary embodiment of a heat exchanger device 236 which builds on the spiral heat exchanger device 36 according to FIG. 1. In contrast to the latter, the heat exchanger device 236 has two layers or windings, instead of only one, in the radial direction. Like the first exemplary embodiment 36 already, the individual turns are at a distance from one another in the direction of the axis of rotation 18. The turbulent oil bath in the housing interior 30 can thereby also reach the intermediate spaces between the turns. Starting from a feed 38, inner turns extend circumferentially and in the direction of the axis 18 with a constant winding diameter as far as an apex of the heat exchanger device 36. The diameter of the winding is expanded here to a larger radius and the turns are guided back circumferentially about the axis of rotation 18 in a reverse direction along the latter. Two windings or layers are thus produced. The outer winding peters out again as the return 40 on the side of the feed 38, in a manner parallel to the latter.

(23) 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. 6.

(24) FIG. 8 shows a fourth exemplary embodiment of a hydrostatic axial piston pump 301 according to the disclosure. It differs from the exemplary embodiment according to FIG. 7 by the modified heat exchanger device 336. The latter, instead of being configured spirally, is now configured in an undulating manner. A ring of circumferentially bent sections extending in an alternating manner parallel to the axis of rotation 18 is strung together here in such a manner that the tube of the heat exchanger device 336 extends in an alternating manner in the circumferential direction around the axis of rotation 18. A temperature profile of the temperature difference ΔT that deviates from the previously shown exemplary embodiments can thereby be realized.

(25) A very similarly constructed exemplary embodiment of a heat exchanger device 436 is shown in FIG. 9. The heat exchanger device 436 differs from the exemplary embodiment according to FIG. 8 in that comparatively few undulating sections are provided.

(26) A final exemplary embodiment of a heat exchanger device 536 is shown in FIG. 10. This heat exchanger device extends spirally incrementally and also has a rectangular cross section of the spiral coils. The latter run horizontally in sections, i.e. in a plane, the normal of which is the axis of rotation 18, and are connected to one another by sections placed in each case against the planes. A heat exchanger device coiled in an in principle incremental and spiral manner is thereby produced.

(27) A hydraulic machine having a housing interior in which an engine is arranged via which mechanical energy can be converted into hydraulic energy, and/or vice versa, in a leakage-affected manner is disclosed. A heat exchanger device for removing a heat flow of the leakage is arranged at least in sections in the housing interior.

(28) A hydraulic axle 7 has a hydraulic machine, shown as the axial piston pump 1, which, in accordance with at least one aspect of the preceding description, at least the following are fixedly connected to the hydraulic machine, in particular to the housing 2 thereof: a drive machine 9, in particular an electric machine, via which a torque can be transmitted to the hydraulic machine, a hydraulic cylinder 11 which can be supplied with pressure medium by the hydraulic machine, and a control block 13, in particular a valve control block, for controlling the pressure medium supply. In addition, as already mentioned above, a tank or a pressure medium container 15 which is connectable to the low pressure and/or high pressure of the hydraulic machine can be provided.

(29) Furthermore, a hydraulic assembly and a hydraulic axle which each have the hydraulic machine are disclosed.

LIST OF REFERENCE SIGNS

(30) 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 piston 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 Annular chamber 36; 136; 236; 336; 436; 536 Heat exchanger device