Self-propelled earth working machine having an electrically driven working apparatus and a balanced weight distribution

Abstract

A self-propelled earth working machine (10) comprises a machine frame (14) and a traveling gear (12), wherein the traveling gear (12) comprises a plurality of rollable drive units (18, 22), wherein the machine frame (14) supports a working apparatus (28) for ground removal work, wherein the working apparatus (28) is accommodated on the machine frame (14) so as to be rotatable about an axis of rotation (R), wherein the earth working machine (10) comprises an electric work drive (50) in order to drive the working apparatus (28) to perform a rotating working movement effecting the ground removal work, wherein the earth working machine (10) comprises an electrical energy source (56), which outputs electrical energy to the working apparatus (28) during the ground removal operation, and wherein the earth working machine (10) comprises a receiving configuration (42) for receiving a conveyor apparatus (40) for transporting removed ground material.

According to the invention, the electrical energy source (56) is an electrical energy store (56), wherein in a reference state, in which the earth working machine (10) stands on level ground (U), the electrical energy store (56) on the one hand and the receiving configuration (42) on the other hand are situated on different sides of a reference plane (BE) that contains the axis of rotation (R) and that is orthogonal to the contact surface of the ground (U).

Claims

1-15. (canceled)

16. A self-propelled earth working machine, comprising: a machine frame; a plurality of rollable drive units supporting the machine frame and rollable on a contact ground surface; a working apparatus for ground removal work supported from the machine frame such that the working apparatus is rotatable about an axis of rotation; an electric work drive configured to drive the working apparatus to perform a rotating working movement effecting the ground removal work during a ground removal operation; an electrical energy store configured to output electrical energy to the working apparatus during the ground removal operation; a receiving configuration configured to receive a conveyor to transport removed ground material; and wherein in a reference state in which the earth working machine stands on level ground the electrical energy store and the receiving configuration are situated on opposite sides of a reference plane containing the axis of rotation of the working apparatus and extending orthogonal to the level ground.

17. The self-propelled earth working machine of claim 16, further comprising: a conveyor mounted on the receiving configuration, the conveyor being configured to convey ground material removed during a ground removal operation away from the working apparatus.

18. The self-propelled earth working machine of claim 16, wherein: the machine frame has a roll axis running parallel to a longitudinal machine direction; and the electric work drive is located in the longitudinal machine direction between the reference plane and the electrical energy store.

19. The self-propelled earth working machine of claim 16, wherein: the rollable drive units form drive axles and at least a portion of the electrical energy store is located above a drive axle.

20. The self-propelled earth working machine of claim 16, wherein: the rollable drive units form front and rear drive axles and at least one portion of the electrical energy store is located above the front drive axle.

21. The self-propelled earth working machine of claim 16, wherein: the machine frame has a roll axis running parallel to a longitudinal machine direction and a pitch axis running parallel to a transverse machine direction perpendicular to the longitudinal machine direction; the plurality of rollable drive units includes at least one front rollable drive unit and at least two rear rollable drive units; and in at least a state of the earth working machine ready for ground removal operation, the working apparatus is located between the two rear rollable drive units with one rear rollable drive unit situated on each side of the working apparatus along the pitch axis.

22. The self-propelled earth working machine of claim 16, wherein: the machine frame has a roll axis running parallel to a longitudinal machine direction; the electrical energy store defines a longitudinal extension of the electrical energy store relative to the machine frame; and the earth working machine further includes at least one functional device selected from the group consisting of a cooling device, an onboard charging device for charging the electrical energy store, and a voltage transformer electrically connected to the electrical energy store, the at least one functional device being located within the longitudinal extension of the electrical energy store relative to the machine frame.

23. The self-propelled earth working machine of claim 16, wherein: the machine frame has a roll axis running parallel to a longitudinal machine direction; the electric work drive includes an alternating current motor; and the earth working machine further includes an inverter located in the longitudinal machine direction between the reference plane and the electrical energy store.

24. The self-propelled earth working machine of claim 23, wherein: the inverter and the electric work drive are situated in a common longitudinal extension of the machine frame.

25. The self-propelled earth working machine of claim 16, further comprising: a hydraulic pump; and a further electric drive configured as a drive of the hydraulic pump.

26. The self-propelled earth working machine of claim 16, further comprising: at least one further electric functional device; and a switch connecting the electrical energy store with the electric work drive and the at least one further electric functional device.

27. The self-propelled earth working machine of claim 26, further comprising: a hydraulic pump; and wherein the at least one further electric functional device includes a further electric drive configured to drive the hydraulic pump.

28. The self-propelled earth working machine of claim 16, wherein: the electrical energy store is at least as far removed from the reference plane as is the receiving configuration.

29. The self-propelled earth working machine of claim 28, wherein: the receiving configuration is at a distance from the reference plane equal to at least one-half of a maximum diameter of a rotational cutting body formed by the rotating working apparatus.

30. The self-propelled earth working machine of claim 28, wherein: the electrical energy store is at a distance from the reference plane equal to at least one-half of a maximum diameter of a rotational cutting body formed by the rotating working apparatus.

Description

[0042] The present invention will be explained in greater detail below with reference to the enclosed drawings. The figure shows:

[0043] FIG. 1 a side view of a specific embodiment according to the invention of an earth working machine in the form of a cold milling machine.

[0044] In FIG. 1, illustrated in a side view, a specific embodiment according to the invention of a self-propelled earth working machine in the form of a cold milling machine is generally indicated by reference numeral 10.

[0045] The self-propelled earth working machine 10 comprises a traveling gear 12 standing on the ground U, the traveling gear 12 supporting a machine frame 14. Further components and modules are attached to the machine frame 14, which are in part rigidly connected to the machine frame 14, and in part movable relative to the machine frame 14, such as for example a front hood 16 swivable about a swivel axis that is orthogonal to the drawing plane of FIG. 1. A lateral surface of the front hood 16 facing the viewer of FIG. 1 is not shown so that the viewer of FIG. 1 is able to look into the front area of the earth working machine 10 surrounded by the front hood 16.

[0046] The self-propelled earth working machine 10 is described in the following with the aid of a Cartesian coordinate system customary for vehicles composed of the roll axis Ro, the yaw axis Gi and the pitch axis Ni. The roll axis Ro runs parallel to the longitudinal machine direction L, the arrowhead of which in FIG. 1 points in the forward travel direction of the earth working machine 10. The yaw axis Gi runs in parallel to the vertical machine axis H, which normally runs orthogonally with respect to the ground

[0047] U, on which the earth working machine 10 stands. The pitch axis Ni runs parallel to the transverse machine direction Q.

[0048] The traveling gear 12 has two front drive units 18, which are situated along the roll axis Ro at the same longitudinal position in straight-ahead travel and thus form a front axle 20 of the traveling gear. Of the two front drive units 18, only the right drive unit 18 situated closer to the viewer of FIG. 1 can be seen in its entirety. The left drive unit 18 situated further away from the viewer of FIG. 1 is slightly offset with respect to the right drive unit 18 along the roll axis Ro toward the rear of the earth working machine 10, in particular by less than the radius of the two equally dimensioned drive units 18, in order to enlarge the maximum possible steering angle in one steering direction.

[0049] The traveling gear 12 also comprises two rear drive units 22, of which only the right rear drive unit 22 situated closer to the viewer of FIG. 1 can be seen. In the operating situation illustrated in FIG. 1, the two rear drive units 22 are also situated at a common longitudinal position along the roll axis Ro and thus form a rear traveling gear axle 24.

[0050] All drive units 18 and 22 shown in FIG. 1 are wheel drive units. In a variant, some or all drive units of the earth working machine 10 may be crawler drive units. The use of crawler drive units in earth working machines of the size and removal capacity shown in FIG. 1 is less common, however, than the use of the wheel drive units shown.

[0051] A working unit 26 is situated on machine frame 14 for joint displacement with the machine frame 14, which is designed for material-removing milling work on the ground U. Visible from the outside is a milling drum housing 30, which in a manner known per se encases, on all sides except toward the ground U, a milling drum 28, rotatable in FIG. 1 about an axis of rotation R running parallel to the pitch axis, as the material-removing working apparatus of the earth working machine, so that a cutting engagement of the milling drum 28 with the ground U is possible. The milling drum 28 is represented merely by a dashed line indicating its cutting circle CC. The cutting circle CC shows the contour of a rotational cutting body 29 formed by the milling drum 28 rotating about the axis of rotation R. The rotational cutting body 29 may have different diameters in different axial sections. Sometimes, the cutting circles CC and thus the local diameters of the rotational cutting body 29 are smaller in the axial end regions of the milling drum 28 than in the axial central regions of the milling drum 28, for example in order to produce a milling path that is profiled in the transverse direction, i.e., in the present illustration, orthogonally with respect to the drawing plane of FIG. 1.

[0052] A milling edge F behind the milling drum housing 30 in FIG. 1 and a ramp A, below machine frame 14, of an already produced milling path indicate that the earth working machine 10 has already partially removed the ground U.

[0053] The machine frame 14 is connected to the rear drive units 22 via lifting columns 32 in a height-adjustable manner. Only the lifting column 32 facing the viewer of FIG. 1 is shown. Since the rear drive units 22 in the operating situation shown in FIG. 1 are alongside each other along the pitch axis Ni of the milling drum 28, possibly with the interposition of further components, for example a milling drum transmission on the side facing away from the viewer of FIG. 1, and since the milling drum 28 is thus located between the two rear drive units 22 in the transverse machine direction Q, the engagement depth T of the milling drum 28 into the ground U may be set by adjusting the machine frame by way of lifting columns 32. As an alternative to the solution shown in FIG. 1, the milling drum 28 may be mounted in height-adjustable fashion on the machine frame in order to change the engagement depth T. In cold milling machines of the size and removal capacity shown in FIG. 1, however, this is also less common than the solution shown in FIG. 1.

[0054] The rear drive unit 22 facing the viewer in FIG. 1and only this drive unitis displaceable by a displacement mechanism 34 from the illustrated position along the roll axis Ro toward the front and along the pitch axis Ni away from the viewer of FIG. 1 to a position in front of the milling drum housing 30, so that in the displaced state the lateral surface of the milling drum housing 30 facing the viewer of FIG. 1 forms a boundary of the movement space of the earth working machine 10 on the right side shown in FIG. 1, which is the so-called zero side of the earth working machine 10. With the zero side rear drive unit displaced to a position in front of the milling drum housing 30, the earth working machine 10 is able to approach obstacles along the pitch axis Ni on the zero side with a particularly small clearance.

[0055] Above the working apparatus 28, there is an operator's platform 36, on which an operator of the earth working machine 10 is able to sit or stand during travel operation and during ground removal operation in order to operate and control the earth working machine 10 using control apparatuses 38 situated on the operator's platform 36.

[0056] In order to convey milled material, that is, ground material removed by the milling drum 28, away from the earth working machine 10, a conveyor apparatus 40 is situated on the rear end of the earth working machine 10. The conveyor apparatus 40 is a belt conveyor apparatus, which conveys milled material along the arrow W from a receiving area 40a near the milling drum 28, where removed ground material is received by the conveyor apparatus, to a longitudinal discharge end 40b of the conveyor apparatus 40, from where the conveyed milled material is discharged in the longitudinal machine direction L.

[0057] Because of the described arrangement of the conveyor apparatus at the rear end of the earth working machine 10, the earth working machine 10 is a rear loader machine.

[0058] The conveyor apparatus 40 is releasably connected to the machine frame 14 via a receiving configuration 42, so that for facilitating a transport of the earth working machine 10 over a longer distance, which the earth working machine 10 does not travel in self-propelled fashion, the conveyor apparatus 40 can be removed from the machine frame 14.

[0059] In the present case, the receiving configuration 42 is formed by three spatially separate partial receiving configurations 42a, 42b and 42c on the machine frame 14. In the illustrated exemplary embodiment, a chain hoist 44, variable in length by a piston-cylinder assemblage 43, is situated on the partial receiving configuration 42a, which may be formed for example by an eye or a hook. An arresting cable 46 is situated on partial receiving configuration 42b, which in the event of a malfunction of the piston-cylinder assemblage 43 prevents the conveyor apparatus 40 from crashing down completely. The partial receiving configuration 42b may therefore also be designed as an eye or hook. The partial receiving configuration 42c may be formed as a mounting flange having a predefined hole pattern or the like, on which a hinged bearing 48 of the conveyor apparatus 40 may be attached, so that an angle of inclination of the conveyor apparatus 40 relative to the machine frame 14 about the axis of inclination NA can be changed within limits constructionally predefined by the chain hoist 44, the tension cable 46, and the hinged bearing 48. Additionally or alternatively, a hinged console may be situated on the partial receiving configuration 42c, which allows for the conveyor apparatus to swivel about a swivel axis SA in parallel to the yaw axis.

[0060] In the present exemplary embodiment, the milling drum 28 of the illustrated earth working machine 10 is driven electrically by an electric motor 50, which forms the electric work drive mentioned in the introduction of the description and which is indicated merely in rough schematic fashion by a dashed line. The electric work drive or electric motor 50, however, is preferably not situated within the space surrounding the milling drum 28 but is rather located at a distance from the milling drum 28 radially outside of that space. The electric motor 50 is thus well protected against the mechanical reactions and the dirt load in the immediate vicinity of the milling drum 28. The drive force of the electric motor 50 is transmitted by a transmission assemblage 52, which is likewise indicated only in rough schematic fashion by a dashed line, to the milling drum 28. The transmission assemblage 52 may be a single transmission or a sequence of two mutually cooperating transmissions of an identical or different type of construction, for example a combination of a belt transmission and a gear transmission, the gear transmission being preferably developed as a planetary transmission.

[0061] In the event that the electric motor 50 is an alternating current motor, for example a synchronous motor, an inverter 54 may be provided on the earth working machine 10, the receiving space of which on the earth working machine 10 preferably overlaps along the roll axis Ro with the receiving space of the electric motor 50.

[0062] As energy source, the earth working machine 10 carries along an electrical energy store 56, which in the illustrated exemplary embodiment is implemented by two cooperating energy store subunits 56a and 56b.

[0063] In order to counterbalance entirely or partially a tipping moment acting on the earth working machine 10 on account of the conveyor apparatus 40 with respect to the rear axle 24 of the traveling gear or with respect to the milling drum 28 engaging with the ground U, the electrical energy store 56, which has a great density and a great weight due to its construction type and the materials used therein, is situated on the other side of a reference plane BE containing the rotation axis R of the working apparatus and extending parallel to the yaw axis Gi of the earth working machine, opposite the conveyor apparatus 40.

[0064] Particularly advantageously, the electrical energy store 56 is situated above the front axle 20 of the traveling gear and thus improves the traction of the front drive units 18 and consequently the steerability of the earth working machine 10.

[0065] The arrow DA in FIG. 1 indicates the distance of the receiving configuration 42 from the reference plane BE, this distance being determined by using the partial receiving configuration 42c closest to the reference plane BE in the exemplary embodiment. The arrow DE indicates the distance of the electrical energy store 56 from the reference plane BE. To determine the distance of the energy store 56, composed of the energy store subunits 56a and 56b, from the reference plane BE, the distance of each energy store subunit 56a and 56b is to be determined and weighted with the weight of the respectively associated energy store subunit 56a and 56b. The distance DE then results from the arithmetic mean of the weighted distances of the energy store subunits 56a and 56b.

[0066] The distance DE is greater than the distance DA, which in turn is greater than the radius of the rotational cutting body 29. In the illustrated exemplary embodiment, the distance DA amounts to approximately 105% to 115% of the radius of the rotational cutting body 29. In the illustrated exemplary embodiment, the distance DE is greater than three times the distance DA. In the illustrated exemplary embodiment, the distance DE amounts to approximately 102% to 108% of three times the distance DA.

[0067] So that the electric work drive (electric motor) 50 can also contribute toward compensating for the tipping moment produced by the conveyor apparatus 40, the electric work drive in the form of the electric motor 50 is also situated on the other side of the reference plane BE, opposite the conveyor apparatus 40. In the illustrated exemplary embodiment, the electric motor 50 is situated between the reference plane BE and the electric energy store 56. Based on the above description, the same is true of the inverter 54.

[0068] The earth working machine 10 may also comprise a further electric motor 58, which drives at least one hydraulic pump 60. The further electric motor 58 and the at least one hydraulic pump 60 are also situated on the other side of the reference plane BE, opposite the conveyor apparatus 40. In the illustrated exemplary embodiment, both the hydraulic pump 60 as well as the further electric motor 58 are situated along the roll axis Ro between the electrical energy store 56 and the reference plane BE, preferably only between these.

[0069] To be able to implement short line paths, an onboard charging device 62 is situated in the longitudinal extension area and preferably also in the vertical extension area of the electrical energy store 56. A voltage transformer 64, which transforms the direct current voltage normally supplied by the electrical energy store 56 to a voltage value different from the terminal voltage of the energy store 56, may likewise be situated, like the onboard charging device 62, in the longitudinal extension area and preferably also in the vertical extension area of the electrical energy store 56.

[0070] The direct current voltage transformed by the voltage transformer 64 can be used to operate for example a direct current ventilator 66, which is provided in direct proximity of the electrical energy store 56 to cool the latter in convective fashion. In the illustrated example, the receiving space of the ventilator 66 along the roll axis Ro overlaps with the receiving space of the electrical energy store 56 on the earth working machine 10. Since the electrical energy store 56 is beveled at its upper front end and the ventilator 66 is situated above the bevel, the receiving space of the ventilator 66 and the receiving space of the electrical energy store 56 overlap with a particularly advantageous utilization of the installation space available overall at the longitudinal front end of the earth working machine 10 even along the yaw axis Gi.

[0071] The travel drive of the self-propelled earth working machine 10 may also have an electric motor, which is likewise supplied with electrical energy by the electrical energy store 56. In a particularly preferred embodiment, the earth working machine 10 comprises a supply switching device 68, for example a direct current intermediate circuit, into which the electrical energy store 56 feeds electrical energy, and to which the electrical work drive 50 and further electric consumers, such as for example the voltage transformer 64 with the ventilator 66 and the further electric motor 58 for operating the hydraulic pump 60 and a travel drive motor, normally with the interposition of voltage transformers and/or inverters, depending on the operating mode of the respective further electric motors, are connected for controlling the further electric motors.