Milling gear assembly

Abstract

The invention relates to a milling gear arrangement for a slot wall milling machine with a stationary plate-shaped gear shield, hollow bearing shafts, one bearing shaft of which is fixedly arranged on each side of the plate-shaped gear shield and is designed for rotatably supporting a preferably hollow output shaft by means of a rolling bearing arrangement, which is arranged between the output shaft and the hollow bearing shaft, wherein the output shaft is designed for rotatingly driving at least one milling wheel, wherein the rolling bearing arrangement can be axially preloaded and fixed on the output shaft or the hollow bearing shaft by means of an axial clamping device.According to the invention, the clamping device has a segment ring with a radial projection, wherein the segment ring is composed of at least two, preferably three, sub-segments and the radial projection engages in an annular groove on the output shaft or the bearing shaft for axially holding the segment ring, the sub-segments are held in a ring shape by a retaining ring to form the segment ring, and several preload elements are arranged on the segment ring, which are designed to exert an axial preload force on the rolling bearing arrangement.

Description

[0001] The invention relates to a milling gear arrangement for a slot wall milling machine with a stationary, plate-shaped gear shield, hollow bearing shafts, one bearing shaft of which is fixedly arranged on each side of the plate-shaped gear shield and is designed for rotatably supporting a preferably hollow output shaft by means of a rolling bearing arrangement, which is arranged between the output shaft and the hollow bearing shaft, wherein the hollow output shaft is designed for rotatingly driving at least one milling wheel, wherein the rolling bearing arrangement on the output shaft or the hollow bearing shaft can be axially preloaded and fixed by means of an axial clamping device, according to the preamble of claim 1.

[0002] A generic milling gear arrangement is described, for example, in EP 4 455 407 A1. The milling wheels of a diaphragm wall cutter typically have a diameter of between 1 and 2 meters. During operation, when milling soil and rock material, large torques must be transmitted to a milling wheel via the milling gear arrangement. Due to operational requirements, the milling wheel, the milling gear arrangement, and the bearings located therein are subjected to considerable shocks and vibrations.

[0003] In particular, a necessary rolling bearing arrangement for rotatably supporting the hollow output shaft on a hollow bearing shaft of the gearbox shield is subject to considerable wear, so that the rolling bearing arrangement must be serviced and, in particular, replaced several times during the service life of a slot wall cutter.

[0004] The hollow output shaft is connected to the milling wheels to transmit torque to them. A relatively large diameter of the output shaft is advantageous from a design perspective. Consequently, the diameter of the rolling bearings mounted on the output shaft is also correspondingly large. These bearings typically have a diameter of approximately 50 cm or more.

[0005] The rolling bearing arrangement for the drive shaft comprises two or more individual rolling bearings, which are typically arranged in a so-called O-arrangement. These bearings are axially preloaded against each other with a defined preload force. Axial preloading of a rolling bearing arrangement on a shaft is typically achieved using a shaft nut, which can be screwed onto a threaded section of the shaft, thereby exerting an axial preload force on the rolling bearing arrangement.

[0006] Setting the defined preload force for a rolling bearing arrangement as precisely as possible has a significant influence on the service life of the individual rolling bearings and thus on the rolling bearing arrangement as a whole.

[0007] Due to the size of the bearings used in milling gear assemblies for slot wall milling machines, these are generally expensive custom-made products. Because of the large shaft diameter of the output shaft to be supported in a milling gear assembly, the necessary components for forming the rolling element assembly are also relatively heavy and not easy to handle during maintenance work. This makes it difficult to precisely adjust the required preload force for a rolling bearing assembly, especially when maintenance work has to be carried out unexpectedly under construction site conditions.

[0008] The invention is based on the TaskThe aim is to specify a milling gear arrangement for a slot wall milling machine which, on the one hand, allows for good adjustability of a preload force and, on the other hand, enables good handling during manufacturing and maintenance work.

[0009] The problem is solved according to the invention by a slotted wall gear arrangement with the features of claim 1. Preferred embodiments of the invention are specified in the dependent claims.

[0010] In the milling gear arrangement, according to the invention, the clamping device has a segment ring with a radial projection, wherein the segment ring is composed of at least two, preferably three, sub-segments and the radial projection engages in an annular groove on the output shaft or the bearing shaft for axially holding the segment ring, that the sub-segments are held in a ring shape by a retaining ring to form the segment ring, and that several preload elements are arranged on the segment ring, which are designed to exert an axial preload force on the rolling bearing arrangement.

[0011] A first aspect of the invention lies in providing a segmented ring, composed of two or more sub-segments, to form the axial clamping device. A sub-segment forms a ring section extending over an angular segment, which, for example, can encompass approximately 180° with two sub-segments and approximately 120° with three sub-segments. A larger number of sub-segments is also possible.

[0012] For manufacturing reasons, it is advantageous if the sub-segments are identical. However, sub-segments of different sizes, particularly with different circumferential angles, are also possible.

[0013] By using a clamping device with such a segmented ring, the need for a large and therefore relatively expensive shaft nut and the associated machining of a threaded section on the shaft being supported can be eliminated. Because the segmented ring is divided into individual sub-segments, even with a relatively large diameter, these segments are relatively easy and efficient to handle during maintenance work on construction sites.

[0014] Another aspect of the invention is that the segment ring has a radial projection which can engage in an annular groove on the output shaft or the bearing shaft. This engagement is made possible by dividing the segment ring into sub-segments. Depending on the arrangement of the segment ring on either the output shaft or the bearing shaft, the radial projection on the segment ring can project radially inwards or radially outwards. By combining such a radial projection with a corresponding groove, reliable axial fixation of the segment ring, and thus of the clamping device, can be achieved. The output shaft can preferably be hollow or solid.

[0015] By sliding on at least one closed retaining ring, particularly axially, the partial segments inserted into the groove can be held in a ring shape to form the segment ring.

[0016] According to a further aspect of the invention, forming such a segmented ring with reliable axial support allows for the arrangement of multiple preload elements on the segmented ring, through which an axial preload force can then be applied and adjusted. By means of a multitude of preload elements, the axial preload force can be adjusted relatively easily and very precisely, even under construction site conditions, using simple tools. When adjusting the axial preload force, the segmented ring, which is held in position and in its ring state by a retaining ring after being inserted into the groove, serves as a counter-bearing. The preload force exerted on the rolling bearing assembly can be transferred to the output shaft or the bearing shaft.

[0017] A preferred embodiment of the invention consists in an adjusting ring being arranged between the rolling bearing assembly and the associated clamping device. This adjusting ring bears against the clamping device on one side and the rolling bearing assembly on the other. Preload elements are designed to contact the adjusting ring, thereby transmitting the axial preload force to the rolling bearing assembly. Firstly, the adjusting ring can serve to make a certain dimensional adjustment for each rolling bearing assembly, ensuring the smallest possible gap between the segment ring and the rolling bearing assembly. Secondly, a further advantage of an adjusting ring is that it achieves an improved, gentler force distribution from the individual preload elements contacting the adjusting ring to the rolling bearing assembly.The individual preload elements do not need to act directly on a bearing ring of one of the rolling bearings. An improved distribution of the preload force exerted by the individual preload elements on the adjusting ring contributes to setting a particularly precise and uniform preload force on the rolling bearing assembly as a whole.

[0018] In principle, the preload elements can be designed in any suitable manner. According to one embodiment of the invention, it is particularly advantageous that the preload elements are designed as screws arranged in corresponding threaded bores in the segment ring. The screws can, in particular, be designed as so-called set screws without a protruding screw head. This allows for a particularly compact design and greater adjustment ranges. Corresponding threaded bores are formed in the segment ring or in the segment segments of the segment ring to accommodate the screws, in order to generate a preload force towards the rolling bearing assembly in conjunction with the screw thread.

[0019] The retaining or clamping ring for forming and holding the segment ring together can be attached to the segment ring in any suitable manner. For example, it can be axially pressed onto the segment ring by friction. An inner diameter is preferably designed to match an outer diameter of the segment ring in order to form a positive fit around at least a portion of it. Slotted retaining rings with a certain clamping force in the circumferential direction can also be used for securing the segment ring. According to a further development of the invention, it is particularly advantageous that at least one connecting element is arranged on the retaining ring, with which the retaining ring can be fixed to the segment ring. This enables a particularly simple, quick, and largely stress-free fixing of the retaining ring to the segment ring.

[0020] According to a further embodiment of the invention, it is particularly advantageous that the at least one connecting element is designed as a connecting screw which engages in a corresponding threaded bore in the segment ring to connect the retaining ring to the segment ring. For this purpose, the retaining ring may have corresponding through-holes, so that a connecting screw with a screw head can pass through the retaining ring and engage in a corresponding threaded bore in the segment ring, thus reliably holding the retaining ring to the segment ring. Preferably, several connecting elements, in particular connecting screws, are arranged around the circumference. Alternatively, a friction-fit connection by means of an interference fit between the retaining ring and the segments may be sufficient to prevent axial movement.Further or alternative measures for axially securing the retaining ring or the clamping ring are possible with differently selected connecting elements, such as retaining rings, retaining clips or wedges.

[0021] According to a further embodiment of the invention, it is preferred that the retaining ring has an approximately L-shaped cross-section and at least partially overlaps the segments in the axial and radial directions. An axially directed leg of the retaining ring can at least partially encompass the segments in the axial direction to hold them in a ring shape to form the segment ring. The radially directed leg of the L-shaped retaining ring serves to receive the connecting elements, in particular the connecting screws. This allows for a particularly compact design of the retaining ring.

[0022] In principle, any structurally sensible bearing variant can be selected to form the bearing arrangement. According to one embodiment of the invention, it is particularly advantageous that the rolling element arrangement comprises at least two rolling bearings, in particular tapered roller bearings and / or ball bearings, which are arranged in an O-arrangement. An O-arrangement is generally advantageous for force absorption as far as possible within the axial extent of the rolling element arrangement.

[0023] The invention further comprises a slot wall milling machine in which at least one milling drive arrangement according to the invention is provided. By incorporating a milling drive arrangement according to the invention, as described above, into a slot wall milling machine, the advantages described above regarding improved adjustment and maintenance options for the rolling bearing arrangement can be achieved.

[0024] In a further development of a slot wall milling machine according to the invention, it is preferred that each milling drive assembly is designed to drive two milling wheels, which are arranged in pairs on a gearbox shield. In the milling drive assembly, two output shafts extend in opposite directions to each other, with each hollow output shaft rotatably mounted on the gearbox shield by means of a rolling bearing arrangement on the associated hollow bearing shaft. The milling wheels can be directly or indirectly connected to the output shafts, in particular, attached to them. For this purpose, a suitable shaft-hub connection can be provided between the output shaft and the milling wheels.

[0025] According to a further embodiment of the invention, it is advantageous that the at least one gear shield is arranged on the underside of a milling frame of the slot wall cutter. Preferably, two gear shields are arranged side by side on the underside of a milling frame, so that a slot wall cutter with two pairs of milling wheels is formed. This enables particularly efficient milling operation.

[0026] In principle, any suitable motor arrangement can be used to generate torque on the diaphragm cutter. In particular, one or more drive motors can be arranged in the cutter frame, with the torque then being transmitted, for example, via a sun shaft to the gearbox shield. A particularly advantageous embodiment of the diaphragm cutter according to the invention consists in a milling wheel drive being arranged as a hub motor on the gearbox shield or on the milling gearbox assembly. The design as a hub motor, which can be arranged coaxially to the output shaft(s), allows for a particularly compact overall design of the diaphragm cutter.Depending on the application and arrangement of the components, deflection and / or transmission gears, in particular one or more bevel and / or planetary gears, preferably one or more planetary gear stages, may be arranged between the milling wheel drive and the output shaft.

[0027] In principle, any suitable drive type can be used for the diaphragm wall cutter. According to one embodiment of the invention, it is particularly advantageous for the milling wheel drive to be designed as a hydraulic or electric drive. This allows the transmission of high amounts of energy with a compact motor design.

[0028] The invention is further described below with reference to preferred embodiments, which are shown schematically in the drawings. The drawings show: Fig. 1 a perspective view of a diaphragm wall milling device with a diaphragm wall milling cutter according to the invention; Fig. 2 a partially cutaway detail view of a milling wheel of the diaphragm wall milling cutter according to the invention. Fig. 1 Fig. 3 a cross-sectional view through a milling drive arrangement according to the invention on a slot wall milling machine according to the invention; Fig. 4 a partially cutaway detail view of a rolling element arrangement of a milling drive arrangement according to the invention; Fig. 5 a partially cutaway detail view of the arrangement according to Fig. 4 with an offset sectional view; Fig. 6 a perspective view of a segment ring for a milling gear arrangement according to the invention; and Fig. 7 a partially cut-away detail view of a hollow bearing shaft with clamping device for a milling gear arrangement according to the invention.

[0029] A milling device 10 with a slot wall milling cutter 30 according to the invention is shown schematically in Fig. 1The milling device 10 has a carrier unit 12, which may have a substructure 14 with a crawler chassis, on which a superstructure 16 may preferably be rotatably mounted.

[0030] According to the illustrated embodiment, the milling device 10 can have a mast 20 which can be articulated to the superstructure 16 via a linkage mechanism 18. A guide rod 22 can be mounted along the mast 20 so as to be substantially vertically displaceable. At the lower end of the guide rod 22, a milling frame 32 of the diaphragm wall cutter 30 with a total of two pairs of milling wheels 40 can be arranged.

[0031] The milling device 10 shown is merely an example; instead of a mast 20, a boom arm can also be arranged. The diaphragm wall cutter 30 can also be vertically adjustable from a support cable on a mast 22 or a boom arm instead of a guide rod 22. The illustrated diaphragm wall cutter 30 is designed as a compact diaphragm wall cutter 30 without a guide frame, with guide elements resting against the walls of the milled slot. Alternatively, the diaphragm wall cutter 30 can also be designed with a milling frame 32, which is designed as a guide frame with contact elements for guiding it against the walls of the milled slot (not shown).

[0032] The bearing arrangement of a milling wheel 40 on a preferably plate-shaped gear shield 52, which is arranged on the underside of the milling frame 32 of the diaphragm wall milling machine 30, is described in more detail below in connection with Fig. 2The preferably plate-shaped gear shield 52 has a hollow bearing shaft 56 with an inner passage 57 on each side. The hollow bearing shafts 56 are fixedly attached to the gear shield 52. The milling wheel 40 is rotatably mounted on the outside of the hollow bearing shaft 56 via a rolling bearing arrangement 60, as shown in the illustrated embodiment. The two bearing shafts 56, arranged opposite each other on the gear shield 52, support two milling wheels 40 in a coaxial configuration, forming a milling wheel pair. The mounting and design of each milling wheel 40 are largely identical, so only one milling wheel 40 will be described below.

[0033] The milling wheel 40 can have an approximately cylindrical circumferential drum 42, on the outer circumference of which plate-like supports 43 for receiving milling teeth 44 can be attached. One or more hinged teeth 49 can be pivotally mounted on the circumferential drum 42 of each milling wheel 40 in order to remove soil material directly below the gear shield 52 by unfolding them in a generally known manner.

[0034] The milling wheel 40 is in contact with the rolling bearing arrangement 60 via an inner support ring 45, which can contribute to damping shocks during operation, and a milling wheel sealing ring 46, and is thus rotatably mounted relative to the hollow bearing shaft 56 and therefore to the gearbox shield 52.

[0035] To seal a sealing gap between the stationary gear shield 52 and the milling wheel 40 which can be rotated relative to it, a gear shield sealing ring 53 can be fixedly attached to the gear shield 52, which interacts with the milling wheel sealing ring 56, which is non-rotatably connected to the milling wheel 40.

[0036] As will be explained in more detail below, one of the Fig. 2 The output shaft (not shown) extends axially outwards from the center of the gearbox shield 52 through a passage 57 in the hollow bearing shaft 56. This output shaft can be non-rotatably connected to the milling wheel 40 in the area of ​​a preferably radially oriented milling wheel hub 48 of the milling wheel 40 via corresponding annular connecting flanges.

[0037] The bearing of the milling wheels 40 on the gear shield 52 and the milling gear arrangement 50 provided for this purpose according to the invention are further described by way of example in connection with Fig. 3This is illustrated. On the central, preferably approximately plate-shaped, gear shield 52, the hollow bearing shafts 56 are fixedly attached to both sides of the gear shield 52. A drive shaft 36 of a drive (not further described) can project through an upper shaft passage 54 in the gear shield 52 into a central area between the two hollow bearing shafts 56. A drive pinion 37 can be fixedly attached to the lower end of the drive shaft 36 and is rotatably mounted relative to the gear shield 52 via a bearing arrangement.

[0038] The conical drive pinion 37 can mesh with a bevel gear 38 to redirect a torque by 90° via the resulting bevel gear stage. The bevel gear 38, which is preferably rotatably mounted relative to the gear shield 52, can transmit the torque to the output shaft 58, which is shown schematically.

[0039] The output shaft 58 can, as is generally known, include one or more gear stages, in particular planetary gear stages, for speed reduction. The output shaft 58 projects through the two hollow bearing journals 56 and is connected to a milling wheel 40 of a milling wheel pair on both sides via schematically indicated radially projecting connecting flanges. For this purpose, the corresponding connecting flange of the output shaft 58 can be connected to the circumferential drum 42, a support ring 45, and / or a milling wheel sealing ring 46 of each milling wheel 40. The support ring 45 and the milling wheel sealing ring 46 can be provided with annular sealing elements.

[0040] The milling wheel 40, which can be driven in this way, is rotatably mounted on the outside of the associated hollow bearing shaft 56 via a rolling bearing arrangement 60 with a first rolling bearing 61 and a second rolling bearing 62. In the illustrated embodiment, the two rolling bearings 61, 62 are designed as ball bearings.

[0041] For preloading the rolling bearing arrangement 60 with the two rolling bearings 61, 62, a clamping device 70 is arranged according to the invention, which is subsequently used in conjunction with the Figures 4 to 7 will be described in more detail.

[0042] According to the representations according to the Figures 4 and 5In the illustrated embodiment, the rolling bearing arrangement 60, comprising the first rolling bearing 61 and the second rolling bearing 62, is arranged on the outside of the sleeve-shaped bearing shaft 56. A clamping device 70 axially preloads the rolling bearing arrangement 60 against an annular shoulder 55 on the hollow bearing shaft 56. The milling wheel 40, with its fixed support ring 45 and milling wheel sealing ring 46, is rotatably mounted via the rolling element arrangement 60 relative to the hollow bearing shaft 56 and the gearbox shield sealing ring 53, which are also fixed to the gearbox shield 52.

[0043] To form the clamping device 70, it has a segmented ring 72, which can preferably be formed from three identical sub-segments 74, as can be clearly seen in Fig. 6The segments 74 of the segment ring 72 can have a radial projection 76 on their radial inner side, which engages appropriately in an annular groove 66 on the outer circumference of the hollow bearing shaft 56. This axially secures the segment ring 72 to the hollow bearing shaft 56.

[0044] The design of the sleeve-shaped hollow bearing shaft 56 with the annular groove 66 incorporated therein, in which the clamping device 70 can be supported in the axial direction, is described in more detail in Fig. 7 clarifies.

[0045] To hold the preferably three segments 74 in a ring shape, they have, for example, an L-shape in cross-section, with a continuous retaining ring 80 being fitted into the resulting shoulder. This holds the segment ring 72 with the segments 74 in its ring shape when they are arranged in the groove 66. The retaining ring 80 can be fixed, in particular screwed, in corresponding threaded bores 77 on the segments 74 by means of connecting elements 86, which can in particular be designed as fastening screws, as illustrated in Fig. 4 As can be seen from the diagram. A plurality of connecting elements 86, preferably evenly distributed around the circumference of the retaining ring 80, can be arranged. In this way, the segment ring 72 is held in a ring shape and axially fixed to the hollow bearing shaft 56.

[0046] Through-holes 75 can be formed in the individual sub-segments 74 along the segment ring 72. Suitable screws 78 can be inserted into these as preload elements, which can apply an axial force to the adjacent first rolling bearing 61 of the rolling bearing arrangement 60, either directly or via an adjusting ring (not shown in the figures), as is clearly shown. Fig. 5 emerges.

[0047] According to the representation Fig. 5 A large number of preload elements 78 can be arranged uniformly along the circumference of the segment ring 72, so that a particularly precisely adjustable and uniformly distributed preload force can be applied from the clamping device 70 to the rolling bearing arrangement 60.

Claims

1. Milling gear arrangement for a slot wall milling machine (30) comprising: - a stationary, plate-shaped gear shield (52), - hollow bearing shafts (56), one bearing shaft (56) being fixedly arranged on each side of the plate-shaped gear shield (52) and designed to rotatably support a preferably hollow output shaft (58) by means of a rolling bearing arrangement (60), which is arranged between the output shaft (58) and one of the hollow bearing shafts (56), - wherein the output shaft (58) is designed to drive at least one milling wheel (40) by rotation, - wherein the rolling bearing arrangement (60) can be axially preloaded and fixed on the output shaft (58) or the hollow bearing shaft (56) by means of an axial clamping device (70), characterized by - thatthe clamping device (70) has a segment ring (72) with a radial projection (76), wherein the segment ring (72) is composed of at least two, preferably three, partial segments (74) and the radial projection (76) engages in an annular groove (66) on the output shaft (58) or the bearing shaft (56) for axially holding the segment ring (72), - that the partial segments (74) for forming the segment ring (72) are held in a ring shape by a retaining ring (80) and - that Several preload elements (78) are arranged on the segment ring (72), which are designed to exert an axial preload force on the rolling bearing arrangement (60).

2. Milling gear arrangement according to claim 1, characterized by thatAn adjusting ring is arranged between the rolling bearing arrangement (60) and the associated clamping device (70), which rests on the clamping device (70) on one side and on the rolling bearing arrangement (60) on the other, and the preload elements (78) are designed to contact the adjusting ring, through which the axial preload force can be transmitted to the rolling bearing arrangement (60).

3. Milling gear arrangement according to claim 1 or 2, characterized by that the preload elements (78) are designed as screws which are arranged in corresponding threaded bores (75) in the segment ring (72).

4. Milling gear arrangement according to one of claims 1 to 3, characterized by that at least one connecting element (86) is arranged on the retaining ring (80) with which the retaining ring (80) can be fixed to the segment ring (72).

5. Milling gear arrangement according to claim 4, characterized by thatthe at least one connecting element (86) is designed as a connecting screw which engages in a corresponding threaded bore (77) in the segment ring (72) to connect the retaining ring (80) to the segment ring (72).

6. Milling gear arrangement according to one of claims 1 to 5, characterized by that the retaining ring (80) has an approximately L-shaped cross-section and overlaps the sub-segments (74) at least partially in the axial and radial direction.

7. Milling gear arrangement according to one of claims 1 to 6, characterized by that the rolling element arrangement (60) comprises at least two rolling bearings (61, 62), in particular tapered roller and / or ball bearings, which are arranged in an O-arrangement.

8. Slot wall cutter, characterized by that at least one milling gear arrangement (50) according to one of claims 1 to 7 is provided.

9. Slot wall milling machine according to claim 8, characterized by thatEach milling gear arrangement (50) is designed to drive two milling wheels (40) which are arranged in pairs on a gear shield (52).

10. Slot wall milling machine according to claim 8 or 9, characterized by that that at least one gear shield (52) is arranged on the underside of a milling frame (32) of the diaphragm wall milling machine (30).

11. Slit wall milling machine according to one of claims 8 to 10, characterized by that a milling wheel drive is arranged on the gear shield (52) or on the milling gear assembly (50) as a hub motor.

12. Slit wall milling machine according to claim 11, characterized by that The milling wheel drive is designed as a hydraulic or electric drive.

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