Adaptation of a hydraulic motor

Abstract

The invention relates to a hydraulic axial piston machine (1) of dry case type of construction, whose case (2) is provided for connection to a gearing case (21) so as to form a fluid-tight overall case. The case (2) has openings (10) which permit the passage of leakage hydraulic fluid or of lubricant into the gearing case (21). By means of this design, splashing losses of the axial piston machine (1) are eliminated, and the leakage hydraulic fluid or the lubricant serve for the lubrication both of the axial piston machine (1) and of the gearing (20).

Claims

1. Hydraulic axial piston machine (1) of dry case type of construction, having a case (2) for accommodating a drive assembly (4) which can be adjusted by means of an adjustment device (3) and which serves for delivering hydraulic liquid, and having a drive shaft (5) which is operatively connected to the drive assembly (4) and which is mounted in the case (2) by means of bearings (6, 7) so as to be rotatable about its longitudinal axis (8), wherein neither the drive assembly (4), the drive shaft (5) nor the bearings (6, 7) thereof run in a sump (9) of the hydraulic liquid, and the case (2) has openings (10), via which leakage hydraulic liquid and lubricant can flow out of the case (2), and a fastening flange (11), which is arranged, transversely with respect to the longitudinal axis (8) of the drive shaft (5), between the adjustment device (3) of the axial piston machine (1) and the openings (10) in the case (2).

2. Axial piston machine according to claim 1, having a first bearing region (12) and a second bearing region (13) which are provided on the drive shaft (5) for the purpose of accommodating rolling or plain bearings, and having a drive input/output region (14) which is arranged on the drive shaft (5), for the purposes of driving or extracting power from the drive shaft (5), wherein the first bearing region (12) is arranged within the case (2).

3. Axial piston machine according to claim 2, in which the drive input/output region (14) is arranged between the first bearing region (12) and the second bearing region (13).

4. Axial piston machine according to claim 2, in which the second bearing region (13) is arranged between the first bearing region (12) and the drive input/output region (14).

5. Axial piston machine according to claim 2, in which the second bearing region (13) and/or the drive input/output region (14) are arranged outside the case (2).

6. Axial piston machine according to claim 1, in which, in the installed state of the axial piston machine (1), the openings (10) in the case (2) are arranged at the lowest point of the case (2).

7. Axial piston machine according claim 1, in which the fastening flange (11) is equipped with sealing means (15).

8. Axial piston machine according to claim 2, in which a tapered-roller bearing is provided at the first bearing region (12) for the mounting of the drive shaft (5) in the case (2) of the axial piston machine (1).

9. Axial piston machine according to claim 2, in which an inner ring (16) of a rolling or plain bearing is arranged in the second bearing region (13) of the drive shaft (5).

10. Axial piston machine according to claim 1, in which lubricant ducts (17) are formed at least partially by a central bore (18) arranged in the drive shaft (5) and by transverse bores (19) which intersect the central bore (18).

11. Hydraulic drive having an axial piston machine (1) according to claim 1 and having a gearing (20) with a gearing case (21) onto which the case (2) of the axial piston machine (1) is flange-mounted such that the two cases (2, 21) together surround an interior space which is sealed in fluid-tight fashion to the outside, a gearwheel (22) of the gearing (20) engages into the drive input/output region (14) of the drive shaft (5) of the axial piston machine (1), and the openings (10) in the case (2) of the axial piston machine (1) are arranged such that leakage hydraulic liquid and/or lubricant can flow into the gearing case (21).

12. Hydraulic drive having an axial piston machine (1) according to claim 1, in which, in a gearing case (21), there is provided a bearing receiving region (23) for accommodating a second bearing region (13) of the drive shaft (5) of the axial piston machine (1).

13. Hydraulic drive according to claim 12, in which a floating bearing for the mounting of the drive shaft (5) is designed for receiving the second bearing region (13).

14. Hydraulic drive according to claim 11, characterized in that pump means are provided for removing leakage hydraulic liquid and/or lubricant from the gearing case (21).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a cross section through an axial piston machine of dry case type of construction according to the invention; and

(2) FIG. 2 shows a cross section through an axial piston machine of dry case type of construction according to the invention in a further embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(3) FIG. 1 illustrates a cross section through a hydraulic axial piston machine 1 of dry case type of construction according to the invention in a first embodiment. The axial piston machine 1 is in this case shown, by way of example, as an adjustable motor or pump of oblique axis type of construction, which has, in a case 2, a drive assembly 4, the valve segment 25 of which is engaged on by an adjustment device 3. The basic design and mode of operation of an axial piston machine 1 of said type are familiar to a person skilled in the art, such that no further explanations will be given in this regard.

(4) The drive assembly 4 has a drive shaft 5 which is mounted, in a first bearing region 12 and a second bearing region 13, in a respective bearing 6, 7. The bearing 6 in the first bearing region 12 is in this case in the form of a tapered-roller bearing, whereas the bearing 7 in the second bearing region 13 is shown as a rolling bearing with an inner ring 16. The longitudinal axis of the drive assembly 4 is defined by the longitudinal axis 8 of the drive shaft. The drive shaft 5 is equipped with a central bore 18 in the direction of its longitudinal axis 8, from which central bore a transverse bore 19 branches off. Via said lubricant ducts 17 which are shown by way of example, hydraulic fluid and/or lubricant can be supplied from the outside to the axial piston machine 1. In an embodiment of the invention, it is particularly preferable here if the same hydraulic fluid is used both for the operation of the axial piston machine and for the lubrication of the axial piston machine 1 and of the downstream gearing 20.

(5) On the front end of the drive shaft 5, which projects out of the case 2 as per FIG. 1, there is arranged a gearwheel 22 which meshes with a gearwheel 24 of a gearing 20. The position of the gearwheels 22 and 24 defines the drive input/output region 14 of the axial piston machine 1, which in this case is situated in an end region of the drive shaft 5 and thus outside the first and second bearing regions 12, 13. In this embodiment, the drive shaft 5 is mounted only in the case 2 of the axial piston machine 1, but not in the gearing case 21 of the gearing 20.

(6) The case 2 of the axial piston machine 1 is connected by way of its fastening flange 11 to the gearing case 21, wherein in particular, an overall case which is sealed in fluid-tight fashion to the outside is formed by way of sealing means 15 arranged between the two cases 2, 21. The connection of the two cases 2, 21 is realized by way of a screw connection not shown in FIGS. 1 and 2. As a sealing means, use may for example be made of O-rings or of flat seals adapted to the shape of the fastening flange.

(7) According to the invention, the case 2 has at least one opening 10 which, in the installed position of the axial piston machine 1, is situated in the gearing case 21 in the interior of the overall case spanned by both cases. Said opening or the openings 10 permit the passage of leakage hydraulic liquid or lubricant from the interior of the axial piston machine 1 into the gearing case 21. For this purpose, it is expedient if at least one of the openings 10 is, in the installed position, situated in the lowest region of the case 2, as shown in FIG. 1. It is self-evident that, in the case of some other position of the openings 10 in the case 2, fluid can pass from the interior of the case 2 into the gearing case 21 as the moving parts of the drive assembly 4 effect turbulence or atomization of leakage fluid or lubricant, which can pass through the openings 10 into the gearing case 21.

(8) The gearing 20 shown in an exemplary structural form in FIG. 1 has a gearwheel 24 which is arranged on a shaft 26 which is mounted on the gearing case 21 by means of bearings 27. The shaft 26 may serve as a drive input or output shaft for a drive or a consumer, wherein it is self-evident that further components such as further gearwheels or clutches may be provided. In one embodiment of the invention, it is self-evidently also possible for the gearing 20 to be in the form of a planetary gear set.

(9) The lowest region of the gearing case 21 in the installed position of the axial piston machine 1 with the gearing 20 is provided as a sump 9 for lubricating and leakage fluid. Said fluid originates from different regions of the drive assembly 4 and enters the gearing 20 from the axial piston machine 1 via the openings 10 in the case 2. In the gearing, said fluid serves for the lubrication of the gearing 20, whereupon it collects in the sump 9. This is indicated in FIG. 1 by the dashed arrows. From the sump 9, the lubricating and leakage fluid that has flowed in is removed by pump means (not shown here) and conducted into a tank and/or supplied again to the lubricant ducts 17 of the axial piston machine 1.

(10) FIG. 2 shows a modified exemplary embodiment of an axial piston machine 1 according to the invention in cross section. All of the reference signs used in FIG. 1 are also used in FIG. 2 to designate the same structural features.

(11) The exemplary embodiment as per FIG. 2 differs from that as per FIG. 1 merely in that the drive input/output region 14 is arranged between the first bearing region 12 and the second bearing region 13 of the drive shaft 5. The bearing 7 of the drive shaft 5 is, for this purpose, arranged in the gearing case 21. Said bearing 7 is thus situated outside the case 2 of the axial piston machine 1 and is not assigned to said case. Accordingly, the case 2 of the axial piston machine has only one bearing 6 for the drive shaft 5, which bearing is shown in this case as a tapered-roller bearing, and thus in a preferred type of construction.

(12) The second bearing 7 in the gearing case 21 receives a bearing region 13 of the drive shaft 5 of the axial piston machine 1 in a bearing receiving region 23. Accordingly, on said bearing region 13, there is arranged an inner ring 16 of a floating bearing whose outer ring is held in a bearing shell of the gearing case 21.

(13) The mode of operation and the further details of this exemplary embodiment correspond fully to those of FIG. 1, such that the explanations given in this regard apply in this case also.

(14) With the type of construction of the axial piston machine 1 according to the exemplary embodiment illustrated in FIG. 1, it is possible for the axial piston machine 1, for example for testing purposes, to be operated on its own, that is to say without being installed into a gearing case; all the parts necessary for this are arranged in or on the case 2. In particular, both of the bearings 6, 7 of the drive shaft 5, such as are required for operation, are already present. In the exemplary embodiment of FIG. 2, only one bearing 6 of the drive shaft 5 is provided in the case 2 of the axial piston machine 1. Since the second bearing 7 is provided by the gearing case 21, it is necessary, for the operation of the axial piston machine 1 without the gearing case 21, to use an apparatus which provides a second bearing receptacle 7.