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 to mill 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, the primary drive unit comprising 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, with respect to a rotation axis of a crankshaft of the internal combustion engine, the 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 arrangement as seen in an axial direction of the crankshaft, wherein in two V-legs of the V-shaped arrangement, starting from a base point of the V-shaped arrangement formed by the rotation axis of the crankshaft, in each case one of the at least two air filters is positioned above in a vertical direction above one of the at least two hydraulic pumps, wherein the hydraulic tank is arranged between the two V-legs.

3. The self-propelled ground milling machine according to claim 1, wherein the hydraulic tank is minor-symmetrical with respect to a vertical reference plane running along a rotation axis of a crankshaft of the internal combustion engine.

4. The self-propelled ground milling machine according to claim 1, further comprising a functional unit comprising the hydraulic tank, the pump transfer gear and the at least two hydraulic pumps is configured as a coherent pre-assembly group comprising a mounting frame independent of the machine frame.

5. The self-propelled ground milling machine according to claim 4, wherein the functional unit is removable as a whole from the ground milling machine and has at least one connection device to connect or engage with an external lifting device.

6. The self-propelled ground milling machine according to claim 5, wherein the connection device is positioned on the functional unit such that the functional unit is essentially balanced with the lifting device.

7. The self-propelled ground milling machine according to claim 4, wherein the functional unit further comprises at least one of an air filter, a clutch between the internal combustion engine and the pump transfer gear and a shifting clutch between the pump transfer gear and a traction roller.

8. The self-propelled ground milling machine according to claim 1, wherein the machine frame has a bearing mount to support at least one of the internal combustion engine and the pump transfer gear, and a frame recess in an axial extension direction of a crankshaft of the internal combustion engine away from the internal combustion engine such that a top side of the machine frame is lower in a vertical direction below at least one of the internal combustion engine, the pump transfer gear and a shifting clutch.

9. The self-propelled ground milling machine according to claim 1, wherein the machine frame includes, in a region of a frame recess, a bottom side that runs horizontally in a straight line at a same level as a region of the machine frame adjoining the frame recess.

10. The self-propelled ground milling machine according to claim 1, further comprising a cooling air ducting having at least one suction fan in a rear region of the ground milling machine, which is arranged such that the fan blows heated cooling air out of the ground milling machine in a direction obliquely upward and to a rear of the ground milling machine.

11. The self-propelled ground milling machine according to claim 1, wherein the hydraulic tank is arranged completely in front of an engine block of the internal combustion engine in an axial direction of a crankshaft of the internal combustion engine.

12. The self-propelled ground milling machine according to claim 1, wherein the hydraulic tank extends in an axial direction of a crankshaft of the internal combustion engine above the crankshaft over the pump transfer gear and at least one of a shifting clutch and a drive roller of a traction drive.

13. The self-propelled ground milling machine according to claim 1, wherein the hydraulic tank is arranged in an axial direction of a crankshaft of the internal combustion engine at a same level as at least one air filter.

14. The self-propelled ground milling machine according to claim 1, wherein the hydraulic tank is arranged in an axial direction of a crankshaft of the internal combustion engine at a level of the at least two hydraulic pumps.

15. The self-propelled ground milling machine according to claim 1, wherein the hydraulic tank extends in an axial direction of a crankshaft of the internal combustion engine entirely within a drive train arranged sequentially in the axial direction and comprising a clutch flanged to the internal combustion engine, the pump transfer gear, a shifting clutch, and a drive roller of a traction drive.

16. The self-propelled ground milling machine according to claim 1, wherein at least one air filter is arranged at least one of being in front of, behind and next to the hydraulic tank in a longitudinal direction of the ground milling machine and/or horizontally and transversely to a rotation axis of a crankshaft of the internal combustion engine.

17. The self-propelled ground milling machine according to claim 1, wherein the hydraulic tank, at least two air filters, the pump transfer gear and the at least two hydraulic pumps are arranged essentially symmetrically with respect to one another, with respect to a minor plane extending vertically and along a rotation axis of a crankshaft of the internal combustion engine.

18. The self-propelled ground milling machine according to claim 1, wherein the at least two hydraulic pumps are arranged on the pump transfer gear, at least one air filter is positioned next to the hydraulic tank, and the hydraulic tank is arranged above a rotation axis of a crankshaft of the internal combustion engine with respect to a horizontal reference plane.

19. The self-propelled ground milling machine according to claim 1, wherein the machine frame includes, in a region of a frame recess, additional stabilization in a form of material thickening in the region of the frame recess.

20. The self-propelled ground milling machine according to claim 1, further comprising a cooling air ducting having an exhaust gas outlet arranged downstream of a suction fan in a blowing direction such that exhaust gases exiting the exhaust gas outlet are conveyed directly into a cooling air conveying stream.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will be explained in more detail below by reference to the embodiment examples shown in the FIGS.; In the schematic FIGS.:

(2) FIG. 1 is a side view of a ground milling machine of the center rotor type;

(3) FIG. 2 is a schematic top view of individual components of the ground milling machine of FIG. 1;

(4) FIG. 3 is a top view of a drive assembly in the axial direction of the crankshaft; and

(5) FIG. 4 is a side view of the drive assembly of FIG. 3.

DETAILED DESCRIPTION

(6) Structurally or functionally like components are designated by like reference numerals in the FIGS., although not every recurring component is designated separately throughout the FIGS.

(7) 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 conveyor 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).

(8) 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.

(9) 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 33.

(10) FIG. 2 illustrates that the hydraulic tank 23, with respect to its extension in the direction of the rotation axis, extends over the clutch 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.

(11) 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.

(12) 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.

(13) 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.

(14) 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.

(15) 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.

(16) 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.