DRIVE DEVICE FOR A DIAPHRAGM WALL CUTTER

Abstract

The invention relates to a drive device for a diaphragm wall cutter, with a hydraulic motor, a gear unit, to which at least one cutting wheel of the diaphragm wall cutter can be connected on the output side, and a drive shaft which connects the hydraulic motor to the gear unit, wherein the drive shaft is mounted by way of at least one drive shaft bearing which is arranged between the hydraulic motor and the gear unit, wherein the drive shaft bearing has a lubricant feed line which is connected to a leakage discharge line of the hydraulic motor and/or to the hydraulic circuit in order to operate the hydraulic motor, and is configured to lubricate the drive shaft bearing with hydraulic oil.

Claims

1. A drive device for a diaphragm wall cutter having at least one cutting wheel comprising: a hydraulic motor; a gear unit to configured to connect on the output side to at least one cutting wheel of the diaphragm wall cutter; and a drive shaft connecting the hydraulic motor to the gear unit, wherein the drive shaft is mounted by at least one drive shaft bearing which is between the hydraulic motor and the gear unit, and wherein the drive shaft bearing has a lubricant feed line connected to a leakage discharge line of the hydraulic motor and/or to the hydraulic circuit to operate the hydraulic motor, and is configured to lubricate the drive shaft bearing with lubricant.

2. The drive device of claim 1, wherein the hydraulic motor is formed free of shaft seals at the outlet of the motor shaft from the motor housing and the lubricant feed line has a leakage collecting inlet which engages around and/or under the motor shaft and/or its outlet from the motor housing.

3. The drive device of claim 1, wherein the hydraulic motor is above the drive shaft and faces the drive shaft with the motor shaft of the hydraulic motor pointing downward and aligned coaxially with the drive shaft while standing upright overhead.

4. The drive device of claim 1, wherein the lubricant inlet comprises a fresh oil inlet connected to a portion of the hydraulic circuit upstream of the hydraulic motor and adapted to lubricate the drive shaft bearing with fresh hydraulic oil.

5. The drive device of claim 1, wherein the drive shaft bearing comprises a bearing sleeve, within which a coupling sleeve is rotatably mounted, wherein the coupling sleeve connects the drive shaft to the motor shaft in a rotationally fixed manner.

6. The drive device of claim 5, further comprising a seal for sealing the coupling sleeve with respect to the drive shaft and/or the coupling sleeve is connected to the drive shaft in an oil-tight manner, so that the coupling sleeve forms a collecting chamber for hydraulic oil.

7. The drive device of claim 6, wherein the bearing sleeve is connected with one end face to the motor housing of the hydraulic motor and/or embraces the motor shaft of the hydraulic motor emerging therefrom.

8. The drive device of claim 5, wherein the bearing sleeve is connected with one end face to the motor housing of the hydraulic motor and/or embraces the motor shaft of the hydraulic motor emerging therefrom.

9. The drive device of claim 1, wherein the fresh oil inlet leads into the interior of the bearing sleeve and passes through a wall of the bearing sleeve.

10. The drive device of claim 1, further comprising a rotary seal, wherein the rotary seal seals off the bearing sleeve from the coupling sleeve and/or from the drive shaft so that an interior space of the bearing sleeve forms a collecting space for hydraulic oil.

11. The drive device of claim 1, wherein the bearing sleeve has a hydraulic oil inlet and a hydraulic oil outlet at opposite end portions, wherein the hydraulic oil inlet and hydraulic oil outlet are configured so hydraulic oil can be flushed through the bearing sleeve and through the hydraulic oil inlet and hydraulic oil outlet.

12. The drive device of claim 1, further comprising a return for the hydraulic oil passing through the drive shaft bearing into the hydraulic circuit for operating the hydraulic motor.

13. The drive device of claim 1, wherein the bearing sleeve forms a hydraulic oil reservoir for lubricating rolling bearings and/or plain bearings by which the drive shaft and/or the coupling sleeve are rotatably supported.

14. The drive device of claim 1, wherein the coupling sleeve forms a hydraulic oil collecting chamber for lubricating non-rotatable connectors by which the drive shaft is non-rotatably connected to the motor shaft of the hydraulic motor.

15. The drive device of claim 1, wherein a collecting chamber for collecting hydraulic oil is below the bearing sleeve and/or the coupling sleeve.

16. The drive device of claim 15, wherein an oil level sensor for detecting the oil level in the collection chamber is associated with the collection chamber.

17. The drive device of claim 16, further comprising a drain for draining oil collected in the collection space, wherein the drain is associated with the collection space, and wherein the drain comprising a releasable closure.

18. The drive device of claim 15, further comprising a drain for draining oil collected in the collection space, wherein the drain is associated with the collection space, and wherein the drain comprising a releasable closure.

19. A diaphragm wall cutter comprising the drive device of claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The invention is explained in more detail below on the basis of a preferred exemplary embodiment and the corresponding drawings. The drawings show:

[0037] FIG. 1: a schematic, perspective view of a diaphragm wall cutter according to an advantageous embodiment of the invention,

[0038] FIG. 2: A perspective view of the drive device for the cutting wheels of the diaphragm wall cutter of FIG. 1, wherein the drive motor is mounted on an upper section of a bearing plate and the gearbox housing, to which the cutting wheels of the diaphragm wall cutter of FIG. 1 are attached, is arranged in a lower section of the bearing plate,

[0039] FIG. 3: a longitudinal section through the drive device for driving the cutting wheels of the diaphragm wall cutter of the foregoing figures, showing the drive shaft between the cutting wheel transmission and the hydraulic motor and the drive shaft bearing between the hydraulic motor and the gearbox, as well as the rotationally fixed connection between the drive shaft and the hydraulic motor shaft, and

[0040] FIG. 4: an enlarged longitudinal section through the drive shaft bearing and the non-rotating connection between the drive shaft and the motor shaft.

DETAILED DESCRIPTION

[0041] As shown in FIG. 1, a diaphragm wall cutter 1 may have an elongated, upright cutter frame 2, which may be in the form of a beam and/or may comprise two laterally arranged longitudinal guide profiles. At a lower end portion, the cutter frame 2 may have at least two cutting wheels 3 which are arranged side by side and may be rotationally drivable about respective lying axes of rotation, wherein the axes of rotation of the cutting wheels 3 may extend parallel to each other and/or perpendicular to the flat side of the cutter frame 2.

[0042] The cutting wheels 3 can be driven in opposite directions to each other. A cutter drive 4 may be arranged at a lower end portion of the cutting section 2 above the cutting wheels 3 and may comprise one or more drive motors 8, for example in the form of hydraulic motors, which may drive said cutting wheels 3 via a gearbox or one or more gear stages 9.

[0043] As shown in FIG. 1, the cutter frame 2 with the cutting wheels 3 can be raised and lowered by, or suspended from, a basic machine 5. Said basic machine 5 rests on the ground in which the respective trench is to be cut, and may advantageously be movable. In particular, the basic machine 5 may be a cable excavator having a chassis, for example in the form of a tracked chassis 6, wherein the cutter frame 2 may be raised and lowered by an boom 7 of the basic machine 5.

[0044] As shown in FIGS. 2 to 4, the cutting wheel drive 4 may be arranged on, or comprise, a support plate 10 by means of which the drive device may be attachable to said cutter frame 2. For example, said support plates 10 can be a T-shaped support which can be fixed at its upper portion to the cutter frame 2 and can support at its lower portion a drive and/or gearbox housing 11 in which said gearbox stage 9 is at least partially housed.

[0045] The drive motor 8 may, for example, be attached to the upper end of the support plate 10 and drivingly coupled to the gear stage 9 via a drive shaft 12 which may extend inside the support plate 10. Said gear stage 9 may thereby comprise one or more planetary gear stages to drive one of said milling wheels 3.

[0046] As FIG. 3 shows, the two planetary gears 9 by which the cutting wheels 3 are driven may be drivingly connected by a substantially upright drive shaft 12 to the hydraulic motor 8, which may be located above the gears 9 on the support plate 10. Said hydraulic motor 8 may be arranged with its motor shaft stub 16 projecting downwardly from the motor housing 17, preferably coaxial with said drive shaft 12. The hydraulic motor 8 may be arranged with its motor shaft 16 vertical and positioned facing downward.

[0047] As FIG. 4 shows, the motor shaft 16 of the hydraulic motor 8 can be connected to the drive shaft 12 in a rotationally fixed manner by means of a coupling sleeve 21, it being possible for the said coupling sleeve 21 to be seated in a cup-like manner on the motor shaft 16 on the one hand and in a cup-like manner on the drive shaft 12 on the other hand. The non-rotational connection means between the coupling sleeve 21 and the motor shaft 16 or the coupling sleeve 21 and the drive shaft 12 may comprise, for example, a spline profiling, a splined profiling or a polygon profiling.

[0048] Said coupling sleeve 21 may thereby advantageously be rotatably supported by rolling bearings 25, alternatively or additionally by plain bearings, on a bearing sleeve 20 which may surround or receive said coupling sleeve 21. Said bearing sleeve 20 may be fixedly arranged, in particular mounted on the support plate 10 and connect to or support the hydraulic motor 8. In particular, the bearing sleeve 20 may engage around the motor shaft 16 and be connected or secured to the motor housing 17 of the hydraulic motor 8 at the end thereof to support the hydraulic motor 8. The end face of the bearing sleeve 20 may be secured to the support plate 10.

[0049] In order to lubricate the engagement surfaces between the coupling sleeve and the drive shaft 12, or the coupling sleeve 21 and the motor shaft 16, the interior of the coupling sleeve 21 may form part of a lubricant supply 14 to guide leakage oil escaping from the hydraulic motor 8 and/or fresh oil supplied separately to the interior of the bearing sleeve 20 to said engagement surfaces. In particular, the interior of the coupling sleeve 21 can form a leakage collection inlet 18 that can collect leakage oil leaking from the motor shaft 16 or the interface between the motor shaft 16 and the motor housing 17 and direct it to said engagement surfaces. In order to supply sufficient leakage oil to the upwardly open interior of the coupling sleeve 21, a shaft seal which would normally seal the motor shaft 16 against the motor housing 17 may be omitted on the hydraulic motor 8, so that by omitting the shaft seal leakage oil escapes at the outlet of the motor shaft 16 and enters the coupling sleeve 21, in particular at its upwardly open end which surrounds the motor shaft 16 in a cup-like manner.

[0050] To prevent accidental leakage of the leakage oil at the lower end of the coupling sleeve 21, a seal 22 may be provided at the lower end or end portion of the coupling sleeve 21 to seal the coupling sleeve 21 with respect to the drive shaft 12. Said seal 22 may thereby seal the gap provided circumferentially between the drive shaft 12 and the coupling sleeve 21, in particular in a shaft portion adjacent to the non-rotational profiling of the drive shaft 12 or located below this non-rotational connection portion.

[0051] In order to supply hydraulic oil not only to the lubrication points located inside the coupling sleeve 21, but also to the aforementioned rolling bearings 25 provided between the coupling sleeve 21 and the bearing sleeve 20, it is also possible, on the one hand, to make use of the aforementioned leakage oil escaping from the hydraulic motor 8, which may be splashed by the rotating motor shaft 16, in particular if the coupling sleeve 21 does not completely surround the motor shaft 16 as far as the motor housing 17.

[0052] Alternatively or in addition to the leakage oil mentioned, however, fresh oil can also be fed into the gap between the bearing sleeve 20 and the coupling sleeve 21, which is branched off upstream of the hydraulic motor 8 from the hydraulic circuit 15 by means of which the hydraulic motor 8 is driven.

[0053] Advantageously, the bearing sleeve 20 may have a fresh oil inlet 19 which may extend through the wall of the bearing sleeve 20 at the upper end of the bearing sleeve 20 immediately adjacent the motor housing 17, see FIG. 4. By supplying fresh oil at the upper end portion of the bearing sleeve 20 into the interior of the bearing sleeve 20, this fresh oil can run or drip or splash downwardly driven by gravity to lubricate the bearings 25.

[0054] Advantageously, a lower end portion of the bearing sleeve 20 may be sealed by a rotary seal 23 with respect to the drive shaft 12 and/or with respect to the coupling sleeve 21, so that the annular inner space between the bearing sleeve 20 and the coupling sleeve 21 or the drive shaft 12 is sealed downwardly to prevent hydraulic oil from running into the transmission 9 and mixing there with the transmission oil.

[0055] Said seal 22, in particular in the form of a rotary seal for sealing the bearing sleeve 20, may advantageously be arranged below all bearings 25.

[0056] As shown in FIG. 4, a collecting chamber 24 may advantageously be provided below the bearing and coupling sleeves 20 or 21, in particular also below the seal 22 and/or the rotary seal 23, which is formed around the drive shaft 12 or through which the drive shaft 12 passes. Said collecting chamber 24 may be formed, for example, in the support plate 10. Advantageously, a riser tube 26 may define the collecting chamber 24 and extend around or form an elevation at the drive shaft 12 to prevent hydraulic oil collected in the collection chamber 24 from running down the drive shaft 12 and into the transmission 9.

[0057] Said collection chamber 24 may have a drain 27, which may advantageously be provided with a releasable closure 28 to allow the drain 27 to be opened. Said drain 27 is preferably configured to allow hydraulic oil, which may be present in the collection chamber 24, to drain off in a gravity driven manner. For example, the drain 27 may be located at the bottom of the collection chamber 24 and may have a certain slope to allow oil to drain.

[0058] By opening the closure 28, it is possible to check whether there are any leaks at the seals 22 or 23 and whether there is oil in the collecting chamber 24.

[0059] Alternatively or additionally, the presence of oil in the collection chamber 24 can also be checked by an oil level sensor 29, by means of which the level in the collection chamber 24 can be sensed in order to output a corresponding oil level signal, for example to provide it to a machine control system. Based on the oil level in the collection chamber 24, a maintenance signal can be given or a maintenance process can be initiated.