SELF-PROPELLED GROUND MILLING MACHINE

Abstract

The invention relates to a self-propelled ground milling machine, in particular a road cold milling machine, stabilizer or recycler, comprising a milling device for milling the ground at a milling depth, a machine frame supported by front and rear travel units, an internal combustion engine arranged in an engine compartment, a hydraulic system with at least two hydraulic pumps, a pump transfer gear and a hydraulic tank, and an operator platform.

Claims

1. A self-propelled ground milling machine, in particular a road cold milling machine, stabilizer or recycler, comprising a milling device for milling a ground at a milling depth; a machine frame supported by front and rear travel units; a primary drive unit arranged on the machine frame, in particular an internal combustion engine; a hydraulic system having at least two hydraulic pumps, a pump transfer gear and a hydraulic tank; and an operator platform, wherein the hydraulic tank is arranged at least partially in vertical extension of the pump transfer gear above the pump transfer gear.

2. The self-propelled ground milling machine according to claim 1, wherein the hydraulic tank is arranged according to at least one of the following features: it is arranged completely in front of an engine block of the internal combustion engine in the axial direction of the crankshaft of the internal combustion engine; it extends in the axial direction of the crankshaft above the crankshaft over the pump transfer gear and a shifting clutch and/or a drive roller of a traction drive; it is arranged in the axial direction of the crankshaft at a same level as at least one air filter, preferably at least two air filters, more particularly one air filter on each side of the hydraulic tank, the two air filters ideally being adjoined by an air combiner, in particular a V-shaped air combiner, running toward the internal combustion engine; it is arranged in the axial direction of the crankshaft at the level of several hydraulic pumps in particular several tandem arrangements of hydraulic pumps; it extends in the axial direction of the crankshaft entirely within a drive train arranged sequentially in the axial direction and comprising a clutch flanged to the internal combustion engine, a pump transfer gear, a shifting clutch, and a drive roller of a traction drive.

3. The self-propelled ground milling machine according to claim 1, wherein with respect to the rotation axis of the crankshaft, at least two hydraulic pumps lying opposite one another and at least two air filters lying opposite one another are arranged in an essentially V-shaped manner as seen in the axial direction of the crankshaft, wherein in the two V-legs, starting from the base point of the V-shaped arrangement formed by the rotation axis of the crankshaft, in each case one hydraulic pump and in each case one air filter positioned above it in the vertical direction are provided, wherein the hydraulic tank is arranged between the two legs, in particular centrally.

4. The self-propelled ground milling machine claim 1, wherein the hydraulic tank is arranged according to at least one of the following features: at least one air filter is arranged in front of and/or behind and/or next to the hydraulic tank in the longitudinal direction of the ground milling machine and/or horizontally and transversely to the rotation axis of the crankshaft, wherein the at least one air filter is positioned in vertical extension of a hydraulic pump arranged on the pump transfer gear; the hydraulic tank, at least two air filters, the pump transfer gear and at least two hydraulic pumps are arranged essentially symmetrically with respect to one another, in particular with respect to a mirror plane extending vertically and along the rotation axis of the crankshaft; at least two hydraulic pumps arranged on the pump transfer gear, at least one air filter positioned next to the hydraulic tank, and the hydraulic tank are arranged above the rotation axis of the crankshaft with respect to a horizontal reference plane.

5. The self-propelled ground milling machine claim 1, wherein the hydraulic tank is mirror-symmetrical with respect to a vertical reference plane running along the rotation axis of the crankshaft.

6. The self-propelled ground milling machine claim 1, wherein a functional unit comprising the hydraulic tank, the pump transfer gear and at least two hydraulic pumps as well as at least one air filter and preferably additionally at least one of the following elements: clutch between internal combustion engine and pump transfer gear, shifting clutch between pump transfer gear and a traction roller, an additional air filter with air ducting toward the internal combustion engine, is configured as a coherent pre-assembly group, in particular comprising a mounting frame independent of the machine frame.

7. The self-propelled ground milling machine according to claim 6, wherein the functional unit can be removed as a whole from the ground milling machine and has at least one own connection device for contact or engagement for an external lifting device, wherein the connection device is preferably positioned on the functional unit such that the functional unit is essentially balanced in contact with the lifting device both in the state filled with operating fluids and in the empty state with respect to the operating fluids.

8. The self-propelled ground milling machine claim 1, wherein the machine frame has a bearing mount for supporting the internal combustion engine and/or the functional unit and/or the pump transfer gear, a frame recess, in particular a frame taper, being provided in an axial extension of the crankshaft away from the internal combustion engine in such a way that the top side of the machine frame is lowered as far as in the vertical direction below the internal combustion engine and/or the functional unit and/or the pump transfer gear and/or a shifting clutch, in particular a clutch cover of the shifting clutch.

9. The self-propelled ground milling machine claim 1, wherein the machine frame includes at least one of the following features in the region of the frame recess, in particular the frame taper: the bottom side runs horizontally in a straight line at a same level as the region of the machine frame adjoining the frame recess on both sides; the machine frame comprises additional stabilization, in particular material thickening, in the region of the frame recess.

10. The self-propelled ground milling machine claim 1, wherein a cooling air ducting having at least one of the following features is provided: it comprises at least one suction fan in the rear region of the ground milling machine, which is arranged such that it blows heated cooling air out of the ground milling machine in a direction obliquely upward and to the rear; an exhaust gas outlet is arranged downstream of the suction fan in the conveying direction such that exhaust gases exiting the exhaust gas outlet are conveyed directly into the cooling air conveying stream, an outlet opening of the exhaust gas outlet preferably being located in the conveying direction of the cooling air at the level of a fan wheel of the suction fan.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The invention will be explained in more detail below by reference to the embodiment examples shown in the Fig.s; In the schematic Fig.s:

[0022] FIG. 1 is a side view of a ground milling machine of the center rotor type;

[0023] FIG. 2 is a schematic top view of individual components of the ground milling machine of FIG. 1;

[0024] FIG. 3 is a top view of a drive assembly in the axial direction of the crankshaft; and

[0025] FIG. 4 is a side view of the drive assembly of FIG. 3.

DETAILED DESCRIPTION

[0026] Structurally or functionally like components are designated by like reference numerals in the Fig.s, although not every recurring component is designated separately throughout the Fig.s.

[0027] FIG. 1 shows a ground milling machine 1 of the road cold milling machine type (center rotor type) with an operator platform 2 and a machine frame or chassis 3. The ground milling machine 1 is self-propelled and has travel units 6 for this purpose, for example crawler tracks or wheels. During milling operation, the ground milling machine 1 moves in the working direction a over the ground 7 to be processed. While doing so, the ground milling machine 1 mills the ground 7 at a milling depth with a milling drum 9 of a milling device 20 mounted for rotation about the rotation axis 10 in a milling drum box 8. The milled material removed may, for example, be transferred in working direction a via a discharge device 5, for example a conveyor belt, to a transport vehicle not shown and transported away by it. Moreover, the ground milling 1 comprises a drive train 13. In order to cool components of this drive train 13, a cooling air supply is provided, among other things, as part of a cooling system, which is configured such that supply air 11 is drawn in at the top side of the ground milling machine 1 at a point of the ground milling machine 1 that is located behind the operator platform 2 in the working direction a. Via exhaust air openings arranged at the rear of the ground milling machine 1, the exhaust air 12 is blown out to the rear in the opposite direction to the working direction a and diagonally upward (for example through corresponding guide vanes in the outlet region).

[0028] An exemplary drive train 13 of the ground milling machine 1, in particular for a road cold milling machine, is shown schematically in FIG. 2. It comprises an internal combustion engine 14, for example a diesel engine, as the primary drive unit, the crankshaft of which rotates about the rotation axis D. The crankshaft may be connected to a clutch 15. A pump transfer gear 16 may adjoin the clutch in the axial direction of the rotation axis. Several units 18, such as in particular one or more hydraulic pumps, also in tandem arrangement, of a hydraulic system, may be flanged to distributor shafts of the pump transfer gear 16 and driven by it. The hydraulic system may, for example, be configured such that hydraulic pumps are used to drive hydraulic motors, which are used, for example, to drive the travel units 6 or to drive the conveyor 5 of the ground milling machine 1. Other actuators, such as linear actuators, may also be supplied with hydraulic drive energy via this system, for example, for shield control of the milling device 20, for adjustment of the conveyor device 5, etc. All required hydraulic pumps of the ground milling machine 1 may be coupled to the pump transfer gear 16 and supplied with energy by it. A shifting clutch 19 may adjoin the pump transfer gear 16 in the axial direction of the rotation axis, which in turn is in drive connection with a drive roller 21 of a traction drive 22 driving the milling drum 9. The rotation axis D can be parallel to the rotation axis 10 of the milling drum and thus horizontal and perpendicular to the forward direction a.

[0029] Part of the hydraulic system is also a hydraulic tank 23, which, as shown in FIG. 2, is arranged above the pump transfer gear 16 and in the direction of the rotation axis between the internal combustion engine and the traction drive 22. The arrangement may further include two air filters 26 arranged upstream and downstream of the hydraulic tank 23, as viewed in the forward direction a at the level of the hydraulic tank 23. Toward the internal combustion engine, supply lines 27 extend from each of the air filters 26 and, as shown in the top view in FIG. 2, converge at the level of the internal combustion engine to form a common air supply line 28.

[0030] FIG. 2 illustrates that the hydraulic tank 23, with respect to its extension in the direction of the rotation axis, extends over the coupling 15, the pump transfer gear 16 and the shifting clutch 19. Further, in a vertical top view, the hydraulic tank overlaps pumps 18, specifically all of the hydraulic pumps 18 connected to the pump transfer gear 16.

[0031] FIGS. 3 and 4 show a specific embodiment of the functional components of the drive system of the ground milling machine 1 indicated schematically in FIG. 2. In the top view along the rotation axis D shown in FIG. 3, it can be seen that pumps 18 are arranged above the crankshaft to the right and left with respect to the rotation axis, and an air filter 26 is arranged above each pump. This results in an overall V-shaped arrangement of these components relative to one another, in the present case even symmetrical along a plane of symmetry spanned by the rotation axis D and a vertical line. In the free space between the two V-legs of this arrangement projecting from the rotation axis D, the hydraulic tank 23 is arranged in vertical direction above the pump transfer gear 16 and the shifting clutch 19. The hydraulic tank 23 is essentially free of protrusion in the vertical direction relative to the internal combustion engine 14, including supply lines.

[0032] In particular, FIG. 3 illustrates that the hydraulic tank 23 is spatially positioned in close proximity to all pumps 18 arranged on the pump transfer gear 16. In this manner, corresponding line connections between the hydraulic tank 23 and individual pumps can be made very short.

[0033] FIG. 4 illustrates that the functional unit 28 consisting of clutch 15, pump transfer gear 16, shifting clutch 19, traction roller 21, hydraulic tank 23 and air filters 26 projects almost flush with the side boundary of the machine frame 3 indicated in FIG. 4 and even partially projects in this direction along the rotation axis beyond the machine frame 3 in the axial direction. This allows optimal access to these components from outside the machine despite the compact overall arrangement.

[0034] FIGS. 3 and 4 further illustrate the combination of the clutch 15, the pump transfer gear 16, the shifting clutch 19, the traction roller 21, the pumps 18, the air filters 26, and the hydraulic tank 23 into a coherent functional unit 28, which may be flanged to the primary drive unit, particularly via the clutch 15. This functional unit 28 or this functional module comprises a mounting frame 29 which, in particular in cooperation with the individual components, constitutes a support structure separate from the machine frame 3, which enables pre-assembly of the functional unit 28. Further, in this manner the functional unit 28 can be replaced as a whole on the ground milling machine 1 relatively easily.

[0035] Finally, the functional unit 28 comprises lug-shaped connection devices 30, which in the present case may be formed by the mounting frame 29 or, for example, a housing of the pump transfer gear 16.

[0036] Finally, FIG. 3 shows a recess 31 in axial extension of the rotation axis D in the machine frame 3. With the aid of the recess 31, the top side of the machine frame 3 is offset downward in the vertical direction V at the level of the clutch 15, the pump transfer gear 16 and/or the shifting clutch 19, as seen in the forward direction a, in such a way that it does not overlap with these components as seen in the axial direction of the rotation axis D. Preferably, in the vertical direction V, the recess 31 is lowered to such an extent that a free space is obtained in the vertical direction between the top side of the machine frame 3 in this region and these components. This likewise facilitates external access to this part of the drive train. In particular, for example, a clutch bell of the shifting clutch 19 can be easily pulled off along the rotation axis D without colliding with the machine frame 3. Since the machine frame 3 thus has a material taper in the vertical direction in this region, additional material thickenings 32 are provided spanning the recess 31 in the longitudinal direction of the machine frame 3. The extent of the material thickenings 32 in this case correlates essentially with the respective extent of the recess 31 over the course of the recess 31 in the longitudinal extension of the machine frame 3, so that overall a constant load-bearing force is ensured across the recess.