EP1003975A1

EP1003975A1 - Hydraulic unit with fastening device for additional aggregate units

Info

Publication number: EP1003975A1
Application number: EP98946319A
Authority: EP
Inventors: Andreas Voulgaris; Christos Voulgaris
Original assignee: Individual
Current assignee: "Archimedes" Voulgaris Hydraulikmotorenbau GmbH
Priority date: 1997-08-12
Filing date: 1998-08-12
Publication date: 2000-05-31
Anticipated expiration: 2018-08-12
Also published as: DE19734900A1; DE59804071D1; AU9341498A; EP1003975B1; WO1999008000A1; DE19734900C2; ATE217393T1

Abstract

The invention relates to a hydraulic unit comprising a rotor and a stator forming a housing. The hydraulic unit has a bearing provided for between the housing and the rotor, which bearing absorbs axial and radial forces. The rotor is configured as a flanged shaft with a shaft section and a flange section for attaching additional aggregate units to the hydraulic unit. The diameter of the flange section is greater than that of the housing. According to the invention a backing ring can be removably connected to the flanged shaft and rests with at least one inner shoulder on at least one outer shoulder on the housing, with formation of a sliding area. The invention also relates to a backing ring configured accordingly.

Description

Hydraulic unit with fastening device for additional units

The invention relates to a hydraulic unit according to the preamble of claim 1 and a device for fastening a hydraulic unit with an additional unit according to the preamble of claim 14.

Hydraulic units, in particular hydraulic motors of known design for driving additional units, such as, for example, grabs, excavators and other devices, are known. According to the basic structure, these hydraulic units have a housing designed as a stator and a rotor designed as a flange shaft. Between the housing and a shaft section of the rotor there are displacement elements which, when subjected to a hydraulic fluid under pressure, cause the rotor to rotate, and corresponding bearings which absorb axial and radial loads are provided. A flange section is formed in one piece on the shaft section of the rotor, the diameter of which is larger than the diameter of the housing and on which the housing is slidably supported when the rotor rotates. That is, the rotor with the shaft section and the flange section is designed as a flange shaft. In the area of the flange section which projects beyond the outer circumference of the housing, through holes are formed circumferentially, through which fasteners are provided for the corresponding fastening of additional units. Due to the relatively large diameter of the flange section of the flange shaft, the axial loads to which the hydraulic unit is exposed in use are limited. In the known hydraulic units, the shaft section of the flange shaft is supported by an oblique roller bearing arranged on the end facing the housing and the end facing the flange section. Because under the tough operating conditions, there are sometimes considerable radial loads. B. by striking the hydraulic motor on certain obstacles and since the additional units that are attached to the hydraulic unit exert a considerable axial weight on the hydraulic unit, the bearings mentioned must be relatively large, which leads to an increase in the size of the drive unit. In addition, it is necessary to use a different hydraulic unit, which is able to absorb these higher axial loads due to its correspondingly large-sized bearings, for other additional units with, for example, larger masses, which consequently result in a higher tensile load for the hydraulic unit.

It is therefore the object of the present invention to create a hydraulic unit to which a larger axial load can be coupled and which can withstand greater radial loads, and to provide a device for fastening a hydraulic unit with a working device by means of which larger axial and radial loads can be absorbed are without having to replace the hydraulic unit as a whole.

This goal is achieved by a hydraulic unit with the features according to claim 1 and by a device for fastening a hydraulic unit with an additional unit with the features according to claim 14. Appropriate further developments are defined in the respective dependent claims.

The hydraulic unit according to the invention has a rotor, a stator, which forms the housing, and displacement elements, which between The rotor and housing are arranged and to which a correspondingly pressurized hydraulic fluid is supplied in order to set the rotor of the hydraulic unit in rotation. There is an axial and radial force-absorbing bearing between the rotor and the housing. The rotor is designed with a shaft section and a flange section as a flange shaft, which is used to fasten additional units. The diameter of the flange section is larger than the housing diameter, so that the flange section protruding beyond the outer circumference of the housing forms an area through which fasteners can be passed, which serve to fasten an additional unit to the hydraulic unit.

According to the invention, a support ring can be releasably connected to the flange shaft, which is supported by an inner shoulder on an outer shoulder on the housing, forming a sliding area. This support ring is connected to the flange section of the flange shaft and the additional unit by means of fasteners when the additional unit is flanged on. This means that the support ring rotates together with the rotor.

Characterized in that the housing has an outer shoulder and the support ring has an inner shoulder and both shoulders cooperate, the axial load by the additional unit is not only absorbed by the flange portion of the rotor, but also by the housing itself. The surfaces which slide together with the rotor when the support ring rotates thus form a sliding area which serves to absorb axial loads and also radial loads.

A major advantage of such a support ring is that in a hydraulic unit according to the invention the axial loads can be increased due to the force distribution in the flange section of the flange shaft and in the housing. Furthermore, it is through the inner shoulder possible on the support ring and the outer shoulder on the housing, arranged on the flange end of the shaft section of the flange shaft

Completely dispense with the inclined roller bearing. This leads to another

Simplification of the construction of such new hydraulic units.

The sliding area is preferably designed with a bearing play and preferably as a sliding bearing. The sliding area can be limited directly to the area of the inner shoulder of the support ring and the outer shoulder of the housing, which slide against one another in the operating state, or can also extend over the inner surface of the support ring, which extends essentially in the axial direction of the hydraulic unit, which in operation on a Part of the outer circumference of the housing runs around.

According to a further exemplary embodiment, the inner shoulder and the outer shoulder are inclined to one another. This means that this inner shoulder is suitable both for absorbing axial loads and for absorbing radial loads. In this context, “inclined to one another” is to be understood to mean that the one that forms the inner shoulder and the outer shoulder

Surface lies in a plane which is different from a direction running radially with respect to the longitudinal axis of the flange shaft. According to a further preferred exemplary embodiment, the support ring rotates with at least one inner surface on an outer surface of the housing. According to this exemplary embodiment, at least a part of the inner surface, which faces the outer circumference of the housing, is supported in a sliding manner around the housing when the rotor rotates with the support ring mounted.

In addition, according to a further preferred exemplary embodiment, it is possible for an O-ring to be arranged between the inner surface and the outer surface. According to yet another exemplary embodiment, the flange section of the flange shaft has an annular step on its side facing the housing, on which the housing is supported in a sliding manner with a step which is essentially of the same shape. This additional ring step in the area of the flange section of the flange shaft serves to absorb radial loads on the hydraulic unit connected to an additional unit, which can occur, for example, as a result of lateral hitting obstacles, walls, etc. For reasons of the tightness of the hydraulic unit, an O-ring acting as a seal can preferably be provided in the area of the step of the flange section. Such an O-ring prevents hydraulic fluid with which the hydraulic unit is driven from escaping from the interface, ie the sliding area of the housing on the flange section.

According to a further exemplary embodiment, the outer diameter of the support ring is substantially equal to the outer diameter of the flange section of the flange shaft, so that the outer surface of the support ring is essentially flush with the outer surface of the flange section.

The entire support ring is preferably made of a plain bearing material, which can preferably also be self-lubricating. A plain bearing material of this type has the strength required to be able to reliably and securely connect the support ring to the additional unit via the flange section of the flange shaft, and also has the necessary lubricating properties in order to achieve the required sliding properties between the housing and the rotor can.

According to a further exemplary embodiment, an additional lubricant line is provided, which is preferably fed from the interior through the housing to the immediate sliding area for its lubricant supply. In the sliding area, either a separate sliding to be lubricated Bearing can be provided, or it can consist entirely of sliding material according to the above-mentioned embodiment.

A check valve is preferably arranged in the lubricant line. Such a check valve prevents the immediate hydraulic unit from being damaged by the displacement elements and the bearing in the event of pressure surges which may occur during operation.

According to yet another exemplary embodiment, the bearing of the shaft section has an axial and radial bearing that supports only at its end region projecting into the housing. This is possible above all if the support ring has a sufficiently large inner shoulder which interacts with a sufficiently large outer shoulder of the housing and if the flange section of the flange shaft also has an annular step. As a result, both the support ring and the flange section of the flange shaft itself can absorb increased radial and axial loads, so that the bearing of the shaft section of the flange shaft facing the flange section can be dispensed with.

According to a further aspect of the invention, the device, which is used to fasten a hydraulic unit with an additional unit, has a support ring which can be detachably fastened to a flange shaft which forms the rotor of the hydraulic unit and which comprises an inner shoulder, the inner shoulder forming a sliding area on one Outer shoulder of the housing is supported. The hydraulic unit is in particular a hydraulic motor, and the additional unit is in particular a gripper.

A major advantage of this support ring according to the invention is that both increased axial and radial loads not only in the Flange section of the flange shaft, but also can be introduced into the housing. This division of the forces in a given hydraulic unit means that the axial load which can be coupled on and the radial load which can be absorbed during operation can be increased without the hydraulic unit itself having to be replaced under these increased loads. Preferably, the inner shoulder of the support ring and the outer shoulder are inclined to one another, the angle of inclination to a plane extending essentially radially to the longitudinal axis of the shaft section of the flange shaft for the inner shoulder and the outer shoulder being substantially the same. This inclined arrangement of the inner shoulder and the outer shoulder allows both axial and radial loads to be introduced into the housing of the hydraulic unit via the support ring.

According to a further exemplary embodiment, the support ring essentially consists entirely of a plain bearing material, which is preferably self-lubricating. In the event that the strength of the plain bearing material is insufficient or is not self-lubricating, the immediate sliding area between the support ring and the housing can be lubricated by supplying lubricant.

According to a further exemplary embodiment, the support ring has slide bearing material at least in sections of the sliding area. This means that it is not absolutely necessary to provide bearing material on all surfaces of the sliding area.

According to a further embodiment of the invention, the support ring is formed at least in two parts. This is particularly advantageous when, for example, a plurality of inner shoulders and a plurality of outer shoulders are to be provided on the support ring or on the housing, which interact in each case. Additional advantages. Features and possible applications of the present invention will now be explained in detail by means of exemplary embodiments with reference to the accompanying drawings.

Show it:

1 shows a hydraulic unit according to the prior art; 2 shows the area of a hydraulic unit according to the invention, on which a support ring according to the invention acts; 3 shows a further exemplary embodiment of a hydraulic unit according to the invention; Fig. 4 shows a further embodiment of the invention, in which a plain bearing is provided between the outer shoulder of the housing and the inner shoulder of the support ring; 5 shows a further exemplary embodiment of the invention, in which lubricant is supplied to the sliding region via an oil supply line; Fig. 6 shows a cross section of a support ring according to the invention.

1 shows a hydraulic unit according to the prior art. The known hydraulic unit 1 has a rotor 2 and a housing 3. Between the rotor 2 and the housing 3 there are displacement elements 4, which are acted upon by a hydraulic fluid under a corresponding pressure, which causes the rotor 2 of the hydraulic unit 1 to rotate by means of a tooth engagement. The rotor 2 has a shaft section 6 and a flange section 7. The shaft section 6 is supported at its end facing the housing by means of a tapered roller bearing and at its end facing the flange section by means of a tapered roller bearing 21 relative to the housing 3. At opposite the flange section of the rotor of the hydraulic unit opposite end, the hydraulic unit has a tab 20 with a transport or fastening eye. This eye is used, for example, to bring the hydraulic unit into a hanging position with a correspondingly coupled additional unit.

This is the case, for example, when the hydraulic unit 1 is coupled to a gripper, for example. Such an additional unit is connected to the flange section 7 of the rotor 2 by means of screws. These screws pass through the outer circumferential area of the flange section, which protrudes beyond the outer circumference of the housing, through correspondingly provided through openings and can be screwed to the additional unit.

In such a known hydraulic unit, the entire axial load due to, for example, the weight of the additional unit is introduced into the rotor 2 via the outer region of the flange section 7. In order to transmit this axial load to the housing, the bearings 5 and in particular the bearing 21 must therefore be of strong dimensions and must be designed in such a way that both axial and radial loads can be absorbed. Via the direct connection between the flange section 7 of the rotor 2 and the additional unit, only axial forces can be absorbed and transmitted. On the other hand, in use, very large radial loads may also occur if, for example, the hydraulic unit connected to the auxiliary unit experiences substantially radial impacts or impacts due to a side impact on an obstacle.

2 shows a first exemplary embodiment in accordance with the invention.

For reasons of simplicity, the part of the hydraulic unit 1 in which the displacement elements 4 are arranged has been cut away. The Housing 3 is supported in relation to the rotor 2 in the area of the shaft section 6 by means of an oblique roller bearing 21. The flange section 7 of the rotor 2 has a diameter which is larger than the outside diameter of the housing 3. In the part of the flange section 7 which projects beyond the outside diameter of the housing 3, through-openings 19 are provided distributed around the circumference. The housing 3 has a region in the region of the flange section 7 of the rotor 2 which has a larger diameter than the remaining region of the housing. As a result, the housing has an outer shoulder 9. A supporting ring 8 is supported on the part of the flange section 7 of the rotor 2 which projects beyond the outer diameter, the outer diameter of which is essentially flush with the outer diameter of the flange section 7. The support ring 8 has circumferentially distributed through holes which are aligned with the through holes 19 in the outer flange section 7. In the 5 upper part of the support ring 8 is a screw head adequate recess, which receives a screw head in a lowering manner when the support ring 8 is connected to the flange section 7 and the additional unit to be attached to it. The height of the outer shoulder 9 of the housing 3, which extends in the axial direction, is dimensioned such that, in cooperation with the inner shoulder 10 of the support ring 8, it leaves at least one bearing play, so that when the support ring 8 is mounted, its inner shoulder 10 does not rest on the inner shoulder 9 is tensioned, but the inner shoulder 10 and the outer shoulder 9 can slide on each other.

5 In addition, the flange section 7 of the rotor 2 has an annular step 15, which cooperates with a substantially congruent step 16 of the housing 3, essentially in the entire area of the housing which faces the flange section 7 provided with a ring step 15, the Step shape of the ring section 7 corresponds to the step shape of the housing 3. The support ring 8 is made of plain bearing material, so that a special plain bearing between the inner shoulder 10 and the outer shoulder 9 is not provided.

FIG. 3 shows a further exemplary embodiment according to the invention, which essentially corresponds to the exemplary embodiment according to FIG. 2. The difference from the embodiment of FIG. 2 is that the support ring 8 has no recess for lowering a head of a screw serving as a fastener. Rather, the screw head lies fully on the radial ring surface when the support ring 8 is mounted.

Fig. 4 shows a further embodiment according to the invention. The basic structure of the support ring 8 corresponds to that of the exemplary embodiments according to FIGS. 2 and 3. In the exemplary embodiment according to FIG. 4, however, an additional slide bearing 11 is provided between the inner shoulder 10 of the support ring 8 and the outer shoulder 9 of the housing 3. This slide bearing 1 1 can be self-lubricating or externally lubricated. The inner, axially extending surface of the support ring 8, which is supported on the outer surface of the housing 3 in a sliding manner, can likewise be a sliding surface provided with a sliding bearing material. It is possible that only selected areas of the circumferential inner surface 12 of the support ring 8, which is supported on the outer surface of the housing 3, are provided with a plain bearing material. If, however, the support ring 8 is made entirely of a plain bearing material, it is not necessary to additionally form individual areas as a plain bearing. In the area of this sliding surface between the inner surface of the support ring 8 and the outer surface 13 of the housing 3, an O-ring 14 is also provided. Such an O-ring 14 is particularly useful when the slide bearing 1 1 is lubricated externally, so that the O-ring 14 prevents lubricant from the slide bearing 11 between the support ring 8 and the exact 3 escapes. The side of the flange section 7 facing the housing 3 has an annular step 15 corresponding to the exemplary embodiment according to FIGS. 2 and 3. which is congruent in shape to the step 16 formed in the housing, so that the housing, with its side facing the flange section 7, is slidably supported on the flange section.

By means of the support ring 8, it is also possible, for example, that a hydraulic motor serving as a hydraulic unit is mounted under pretension, so that, with appropriate support of the support ring 8, compensation of the clamping forces that occur can be achieved.

5 shows a further exemplary embodiment according to the invention. In this embodiment, an oil supply line 17 is provided for supplying a slide bearing, which in turn is arranged between the outer shoulder 9 of the housing 3 and the inner shoulder 10 of the support ring 8, so that the slide bearing 11 is permanently supplied with lubricating oil. This oil supply line 17 is guided from the interior of the housing, in which hydraulic oil is present, into the region of the sliding bearing 11 on the outer shoulder 9. A check valve 18 is arranged in the oil supply line 17 in order to prevent pressure peaks from possibly occurring back into the interior of the hydraulic unit. With the help of the oil supply line 17, it is possible to compensate for a contact pressure generated by pretensioning, so that optimal conditions for effective lubrication conditions are given.

In order to prevent oil from leaking under pressure between the support ring 8 and the outer surface of the housing 3 when lubricating oil is applied to the slide bearing 11, O-rings 14 are additionally provided for sealing. FIG. 6 shows a cross section through the support ring according to the invention, which corresponds to the exemplary embodiments according to FIGS. 2, 4 and 5. The support ring 8 has an inward shoulder, the inner shoulder 10. This inner shoulder 10 is supported on the outer shoulder 9 of the housing 3 or on a slide bearing arranged between the inner shoulder 10 and the outer shoulder 9, so that higher axial loads on the auxiliary unit can be introduced into the housing 3 via the flange section 7 on the hydraulic unit 1 are. The inner surface 12 of the support ring 8 is designed so that it is essentially slidingly supported on the outer surface 13 of the housing 3 in the contact area. The support ring 8 is preferably formed from a plain bearing material. However, it is also possible that the base material of the support ring 8 is a material of high strength, depending on the respective application, and that at least some sliding bearing materials are provided on the sliding surfaces.

Depending on the dimensions of the outer shoulder 9 of the housing 3 and the inner shoulder 10 of the support ring 8, the axial and - in the case of inclined shoulder surfaces - the radial loads which can be absorbed by the hydraulic unit can be increased considerably by the device according to the invention.

Claims

claims

1. hydraulic unit (1) with a rotor (2), a stator forming a housing (3), in which an axial and radial force-absorbing bearing is provided between the housing (3) and the rotor (2) and the rotor (2 ) with a shaft section (6) and a flange section (7) as a flange shaft (6, 7) for attaching additional units, the flange section (7) having a diameter which is larger than the housing diameter, characterized in that a support ring ( 8) can be releasably connected to the flange shaft (6, 7), which is supported with at least one inner shoulder (10) on at least one outer shoulder (9) on the housing (3) to form a sliding area.

2. Hydraulic unit (1) according to claim 1, characterized in that the sliding area forms a bearing play.

3. Hydraulic unit (1) according to claim 1 or 2, characterized in that the sliding area is designed as a sliding bearing (11).

4. Hydraulic unit (1) according to one of claims 1 to 3, characterized in that the inner shoulder (10) and the outer shoulder (9) are inclined to each other.

5. Hydraulic unit (1) according to one of claims 1 to 4, characterized in that the support ring (8) with at least one inner surface (12) on an outer surface (13) of the housing (3) slidably rotates.

6. Hydraulic unit (1) according to claim 5, characterized in that an O-ring (14) is arranged between the inner surface (12) and the outer surface (13).

7. Hydraulic unit (1) according to one of claims 1 to 6, characterized in that the flange section (7) of the flange shaft (6, 7) on its side facing the housing (3) has an annular step (15) for receiving radial loads on which the housing (3) is slidably supported with an essentially congruent step (16).

8. Hydraulic unit (1) according to one of claims 1 to 7, characterized in that the outer diameter of the support ring (8) is substantially equal to the outer diameter of the flange portion (7) of the flange shaft (6, 7).

9. Hydraulic unit (1) according to one of claims 1 to 8, characterized in that the support ring (8) consists of a plain bearing material.

10. Hydraulic unit (1) according to one of claims 1 to 9, characterized in that a lubricant line (17) leads to the lubricant supply to the sliding area.

1 1. Hydraulic unit (1) according to claim 10, characterized in that a check valve (18) is arranged in the lubricant line (17).

12. Hydraulic unit (1) according to one of claims 7 to 11, characterized in that the bearing of the shaft section (6) has an axial and radial load bearing (5) only at its end region projecting into the housing (3).

13. Hydraulic unit (1) according to claim 12, characterized in that the bearing is an oblique roller bearing.

14. A device for fastening a housing (3) and a flange (6, 7) designed as a rotor (2) having a hydraulic unit (1), in particular a hydraulic motor, with an additional unit, in particular a gripper, characterized in that the device as a support ring (8), which can be detachably fastened to the flange shaft (6, 7) and has an inner shoulder (10), which is supported on an outer shoulder (9) of the housing (3) to form a sliding area.

15. The apparatus according to claim 14, characterized in that the inner shoulder (10) and the outer shoulder (9) are inclined to each other.

16. The apparatus according to claim 14 or 15, characterized in that the support ring (8) consists of a plain bearing material.

17. The apparatus according to claim 16, characterized in that the sliding bearing material is self-lubricating.

18. The apparatus according to claim 14 or 15, characterized in that the support ring (8) comprises plain bearing material at least in sections of the sliding area.

19. Device according to one of claims 14 to 18, characterized in that the support ring (8) is formed at least in two parts.