Groove wall milling machine

Abstract

A groove wall milling machine has a pair of milling wheels (12), a support head (14) between which the pair of milling wheels (12) are rotatably arranged, a base frame (30) at the underside of which at least one support head (14) is mounted, and a milling wheel drive (20) for driving the milling wheels (12) via a drive in the support head, which is lubricated with drive oil. According to the invention, at least one heat exchanger (60) is arranged above the support head (14), and for cooling the drive oil, an oil circuit (50) is configured to which the at least one heat exchanger (60) above the support head (14) is coupled.

Description

Technical Field

[0001] The present invention relates to a slot wall milling machine (or slot wall cutter, Schlitzwandfräse), comprising: at least a pair of milling wheels; at least one support end cover (or end cover, Lagerschild), on which the pair of milling wheels are rotatably arranged; a base frame, on which at least one support end cover is mounted; and a milling wheel drive for driving the milling wheels via a transmission mechanism lubricated by transmission oil in the support end cover. Background Technology

[0002] This type of slot milling machine is known from EP 1 637 794 B1. In this slot milling machine, an oil circuit (Ölkreislauf) is arranged between the milling wheel, located at the lower end of the support end cover, and the frame housing with the milling wheel drive. Oil is transported upward from the milling wheel through the milling end cover to the milling wheel drive in the housing via a drive shaft. Oil return is carried out via a return line in the support end cover. During operation, the support end cover is covered on both sides by the milling wheel and is almost completely blocked by the flow of support slurry (or support suspension, i.e., Stuetzsuspension).

[0003] Another slot milling machine of this type is known from EP 1 580 327 B1. In this slot milling machine, the driving torque of a single drive motor is transmitted to the sun gear via a central drive shaft in a support end cover, and the torque is distributed by the sun gear to each milling wheel pair. Summary of the Invention

[0004] The purpose of this invention is to describe a slot wall milling machine in which particularly high milling power can be guaranteed with reliable lubrication of the transmission assembly used to drive the milling wheel.

[0005] According to the invention, this objective is achieved by a slot wall milling machine according to some aspects of the invention. The invention has several preferred embodiments.

[0006] The groove wall milling machine according to the invention is characterized in that at least one heat exchanger is arranged above the support end cover, and an oil circuit is constructed for cooling the transmission oil, wherein at least one heat exchanger above the support end cover is connected to the oil circuit.

[0007] The basic idea of ​​this invention is based on the understanding that the transmission components in a slot milling machine, especially when milling through hard soil or rock layers, are subjected to enormous forces that can generate intense heating of the transmission oil. Excessive heating of the transmission oil can cause the lubricating film on the gears in contact with each other to break, leading to accelerated wear at the gears and bearings. This can limit milling power and shorten the service life of the transmission.

[0008] To overcome this problem, according to the invention, an oil circuit with at least one heat exchanger is provided through which transmission oil is guided. The heat exchanger is arranged away from the milling section and the support end cover containing the transmission, i.e., above the support end cover. The oil circuit can be formed by means of an oil pipeline.

[0009] According to the invention, targeted cooling is thus achieved in the exposed areas of the liquid-filled milling groove within the housing above the milling wheel and the support end cover. This area provides the possibility of a very large wall structure, preferably plate-shaped, for the heat exchanger at or even above the base frame. Multiple heat exchangers can also be arranged. In this way, even if the transmission oil in the oil circuit is intensely heated, it can be cooled to the desired operating temperature, thereby giving the oil the viscosity desired for constructing a stable lubricating film during operation. This allows for particularly high milling power.

[0010] A preferred embodiment of the invention involves a heat exchanger constructed as a plate that is releasably fixed to a base frame or to a holding device above the base frame. Therefore, the heat exchanger can be mounted on a support rod of the base frame or at a holding device on which the base frame is suspended. The holding device may be a guide rod, a holding cable, and / or a supply line.

[0011] According to an improvement of the invention, it is advantageous that the milling drive is arranged within the housing, and the heat exchanger is constructed in or thereon within the outer wall of the housing. In compact milling machines without guide plates (such as CSM milling machines), the base frame is essentially formed by the housing of the milling wheel drive. Here, the heat exchanger can be compactly constructed within the housing.

[0012] Advantageously, the outer wall of the housing is constructed as a cooling wall, wherein at least one groove is introduced on the inner side of the cooling wall to form an oil guiding channel, and a flexible or tubular conduit is arranged in the groove. At least one outer wall of the housing can be constructed as a cooling wall, in which at least one oil guiding channel is arranged, wherein oil for cooling can be guided through at least one oil guiding channel in the outer wall of the housing.

[0013] A preferred embodiment of the invention is characterized in that the oil guiding channel is constructed in a loop, preferably a meandering shape, within the outer wall of the housing. This allows for particularly intense and rapid cooling of the oil within the cooling wall.

[0014] The heat exchanger is specifically constructed as a removable, fixed, separate plate. Therefore, existing slot wall milling machines can be modified or replaced. The plate can be a two-piece design, with a cover plate concealing the oil guide channels in the base plate. Cooling plates can also be installed, particularly screwed, onto the smooth surface of the housing wall.

[0015] According to an improved embodiment of the invention, a particularly suitable design is achieved by introducing at least one groove on the inner side of the cooling wall to form an oil conduit channel, in which a flexible or tubular conduit is arranged. The groove can here extend in a loop or meandering manner. It is also feasible in principle to directly construct the groove as an oil guiding channel by means of a suitable seal. The use of flexible or tubular conduits, which can be made of metal (preferably stainless steel) or plastic, results in a particularly simple design with high sealing performance.

[0016] In the slot milling machine according to the invention, particularly good cooling can be achieved by the plate heat exchanger comprising a metal with high thermal conductivity, especially aluminum or an aluminum alloy. In particular, a metal with higher thermal conductivity than steel is provided. This results in a particularly strong cooling effect. Thus, in the experiment, approximately 3.2 kW of cooling power was achieved when using steel plates, while approximately 11.2 kW of cooling power was achieved when using aluminum plates.

[0017] Another preferred embodiment of the invention involves providing at least one pump device through which oil is conveyed in the oil circuit. The pump device may be electrically or hydraulically driven, preferably having a variable delivery volume. In particular, the pump device may be driven by a control device that adjusts the flow rate through the oil guide channel based on the current oil temperature (which may be detected, for example, by a temperature sensor). This allows for heat dissipation as needed.

[0018] A particularly simple design of the groove wall milling machine according to the invention is thus achieved, namely, the pump device includes a shaft driven by a milling drive, which has at least one feed screw (Foerderwendel) on its outer side to form a worm pump. The shaft of the pump device can here be rotatably driven by the milling wheel drive via a separate transmission system.

[0019] According to a particular embodiment of the invention, it is particularly advantageous that the shaft is a drive shaft extending from the milling wheel drive device through a support end cover to the milling wheel. The drive shaft extends substantially vertically and has a delivery helix, particularly a groove, on its outer side through which oil is delivered upwards from the milling wheel along the shaft in a shaft channel. This allows for adjustment of the oil delivery direction from the milling wheel to the milling wheel drive device without significant structural costs. The milling wheel drive device preferably comprises one or more hydraulic motors.

[0020] To achieve targeted control of oil flow, an improvement according to the invention can advantageously include a control valve that blocks the oil guide passage at a lower first temperature and releases it at a higher second temperature. The control valve can be operated according to the oil temperature as mentioned above. Specifically, when starting the milling wheel drive at a lower transmission oil temperature, the oil passage is blocked, allowing the transmission oil to heat to operating temperature as quickly as possible. Above the higher second temperature, the control valve can then open and release the oil guide passage. Thus, oil can flow through the oil guide passage into the heat exchanger, thereby achieving appropriate cooling.

[0021] In principle, at least one cooling wall can be arranged at any location on the outer side of the housing or milling frame. According to one embodiment of the invention, it is particularly advantageous to provide at least two cooling walls arranged on the longitudinal side of the housing. This allows for adequate cooling even under particularly intense heating conditions. The housing can be constructed as a grid frame, with one or more cooling plates arranged therein or at the grid frame. Attached Figure Description

[0022] The present invention will now be further described with reference to preferred embodiments, which are schematically illustrated in the accompanying drawings. Wherein:

[0023] Figure 1 A front view of the slot wall milling machine according to the present invention is shown;

[0024] Figure 2 It shows about Figure 1 A partial cross-sectional schematic diagram of the oil guide channel in a slot wall milling machine;

[0025] Figure 3 An enlarged partial cross-sectional view through the cooling wall used in this invention is shown; and

[0026] Figure 4 A schematic diagram of a portion of the oil circuit in a slot wall milling machine according to the present invention is shown. Detailed Implementation

[0027] according to Figure 1 The groove wall milling machine 10 according to the invention has a base frame 30 with a housing 31, on the lower side of which two plate-shaped support end covers 14 are mounted. Milling wheels 12 with multiple milling teeth 13 are rotatably supported on both sides of the support end covers 14 for milling away soil material. Furthermore, a wedge-shaped slurry supply device 16 can be arranged between the two pairs of milling wheels 12 on the lower side of the base frame 30. During milling operation, support slurry and milling slurry can be introduced into the formed milling groove via the slurry supply device 16. The supplied slurry may contain a binder, wherein, by mixing with the milled soil particles (Bodenklein), so-called soil cement can be formed, which can harden in the milling groove to form the groove wall section.

[0028] Plate-shaped adjustment and guide elements 18 are provided along the narrow side of the base frame 30. During milling operation, these adjustment and guide elements can be abutted against the wall of the milling slot, wherein the slot wall milling machine 10 can be guided and adjusted in the milling slot by adjusting the adjustment elements 18 accordingly. On the upper side of the housing 31 of the base frame 30, a cable suspension device or guide rod is provided in a known manner for holding and vertically adjusting the slot wall milling machine 10 in the milling slot.

[0029] To form the heat exchanger 60, a plate-like outer wall 32 is provided on one or preferably two longitudinal sides of the box-shaped base frame 30, the outer wall being constructed such that... Figure 2 and Figure 3 The cooling wall 34 is shown in more detail below. The cooling wall 34 can form the wall of the housing 31.

[0030] according to Figure 3 The heat exchanger 60, with cooling walls 34, is preferably implemented as a flat plate made of stainless steel. The cooling walls 34 have an inner side 35 facing the housing 31 and an opposite outer side 37, which forms the outer side of the housing 31 in the assembled state. A groove 38 is milled along the inner side 35 of the cooling walls 34, the groove being designed according to… Figure 2 The diagram shows a meandering structure. A pipe 40, made of metal tubing (e.g., copper), leads into the annular groove 38. The pipe 40 thus forms an oil guide channel 36 within the cooling wall 34. The pipe 40 has connecting portions 42 at both ends, through which the heat exchanger 60 can be connected to an oil circuit 50, which... Figure 4 The middle part is shown schematically.

[0031] according to Figure 4A strongly schematic illustration shows a partially represented milling wheel drive 20 with numerous support members. For each support end cap 14, a drive shaft 22, shown only partially, extends downwards from the milling wheel drive 20 to the milling wheel 12 located below. The drive shaft 22 has a delivery groove (not shown) on its outer side, which delivers transmission oil from the region of the milling wheel 12 upwards in a direction toward the milling wheel drive 20. The oil flows through the support members and gear assembly of the milling wheel drive 20, shown only schematically. The milling wheel drive 20 preferably includes at least one hydraulic motor and a driven-and-distributed transmission.

[0032] At least a portion of the transmission oil is guided via a pump (not shown) through the supply section (Vorlauf) 44 of the oil circuit 50 to the upper connection of the heat exchanger 60, which has a meandering oil guide channel 36 in the cooling wall 34. The heated oil flows downward through the meandering oil guide channel 36 in the cooling wall 34, dissipating heat therefrom, with its free outer side pointing towards the slurry-filled tank. The oil guide channel 36 can be constructed in the cooling wall 34 with a slight slope, for example, approximately 15°, thereby allowing adjustment of the oil flow without significant pressure consumption.

[0033] Cooled transmission oil is guided back to the milling wheel drive 20 via the return section 46 of the oil circuit 50. Transmission oil can be guided downwards from the milling wheel drive 20 to the milling wheel with the distribution drive via the return line 52. The oil, especially in the area of ​​the distribution drive, is then reheated and guided upwards again via the conveying action of the drive shaft 22 to the heat exchanger 60 above the milling wheel drive 20 and the support end cover 14. To control the flow of oil through the oil guide channel 36, a control valve 28 is provided at the supply section 44 or, as shown, at the return section 46. This control valve can control the oil flow through the oil guide channel 36 at a set temperature, and generally block or fully open the oil flow. This control depends on a temperature sensor (not shown) that measures the temperature of the transmission oil at one or more locations in the oil circuit 50. The cooling circuit may also have branches for pressure balancing of the transmission components.

Claims

1. A slot wall milling machine, which has the following features: - At least one pair of milling wheels, - At least one support end cover, with a pair of milling wheels rotatably arranged on both sides of the support end cover. - A base frame, wherein at least one support end cover is mounted on the underside of the base frame, and - A milling wheel drive mechanism for driving the milling wheel via a transmission mechanism lubricated by transmission oil within the support end cover. Its features are, - At least one heat exchanger is arranged above the support end cover, and - To cool the transmission oil, an oil circuit is constructed, and at least one heat exchanger above the support end cover is connected to the oil circuit. - in, To form the heat exchanger, a plate-shaped outer wall is provided on one or two longitudinal sides of the base frame. The outer wall is constructed as a cooling wall, wherein the outer side of the cooling wall points toward the trough filled with slurry.

2. The slot wall milling machine according to claim 1, characterized in that, The heat exchanger is constructed as a plate, which is releasably fixed to the base frame or to a holding device above the base frame.

3. The slot wall milling machine according to claim 1, characterized in that, The basic frame has a housing, the milling wheel drive is arranged in the housing, and the heat exchanger is arranged in the outer wall of the housing or at the outer wall of the housing.

4. The slot wall milling machine according to claim 3, characterized in that, The outer wall of the housing is constructed as a cooling wall, wherein, in order to form an oil guiding channel, at least one groove is introduced on the inner side of the cooling wall, and a flexible tubing is arranged in the groove.

5. The slot wall milling machine according to claim 1, characterized in that, The plate-shaped heat exchanger comprises a metal with high thermal conductivity.

6. The slot wall milling machine according to claim 1, characterized in that, At least one pump is provided, through which the oil can be delivered in the oil circuit.

7. The slot wall milling machine according to claim 6, characterized in that, The pump device includes a shaft driven by the milling wheel drive, and the shaft has at least one conveying spiral section on its outer side.

8. The slot wall milling machine according to claim 7, characterized in that, The shaft is a drive shaft that extends from the milling wheel drive device through the support end cover to the milling wheel.

9. The slot wall milling machine according to claim 1, characterized in that, A control valve is provided that blocks the oil circuit to the oil guide passage of the heat exchanger at a lower first temperature and releases the oil guide passage at a higher second temperature.

10. The slot wall milling machine according to claim 1, characterized in that, The basic frame has a shell, wherein at least two cooling walls are provided, the cooling walls being arranged on the longitudinal side of the shell.

11. The slot wall milling machine according to claim 3, characterized in that, The outer wall of the housing is constructed as a cooling wall, wherein, in order to form an oil guiding channel, at least one groove is introduced on the inner side of the cooling wall, and a tubular pipeline is arranged in the groove.

12. The slot wall milling machine according to claim 1, characterized in that, The plate-shaped heat exchanger comprises aluminum or an aluminum alloy.

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