Electric drive of mobile apparatus

Abstract

A mobile apparatus includes a main frame, an operating arm connected to the main frame, drive means configured to drive displacing means of the mobile apparatus, such as one or more wheels or tracks, drive means configured to drive the operating arm and a control system, connected to operating instruments for a driver, for controlling the drive means. The drive means for the displacing means includes an electric motor such that the drive of the displacing means is substantially electrical.

Claims

1. A mobile apparatus comprising a main frame with displacing means, a sub-frame arranged rotatably relative to the main frame, wherein the rotatable sub-frame comprises operating instruments for a driver, an operating arm connected to the sub-frame, a first drive configured to drive the displacing means, a second drive configured to drive the operating arm, and a control system, connected to the operating instruments, for controlling the first and second drive, wherein the first drive comprises at least one electric motor such that the first drive is substantially electrical; said mobile apparatus further comprising at least one energy storage unit for storing and supplying electrical energy to the at least one electric motor, a generator operatively connected to the at least one energy storage unit, and a combustion engine operatively connected to the generator, wherein the combustion engine and generator are configured to supply electrical energy to the at least one energy storage unit, said generator being placed in the main frame.

2. The mobile apparatus as claimed in claim 1, wherein the displacing means and the first drive are arranged in or on the main frame and that at least one energy storage unit for supplying energy to the at least one electric motor for the displacing means is arranged in or on the main frame; said mobile apparatus further comprising a rotary joint (slip ring) between the main frame and the rotatable sub-frame configured to feed control signals between the main frame and the rotatable sub-frame, from the control system to the first drive.

3. The mobile apparatus as claimed in claim 1, wherein at least one of the first and second drive is embodied as an electric motor and is also configured to function as a generator, wherein a combustion engine is connected to the electric motor using a connectable and disconnectable coupling.

4. The mobile apparatus as claimed in claim 1, also comprising a hydraulic pump configured to supply hydraulic energy, wherein the hydraulic pump is provided with a drive embodied as an electric motor and configured to be controlled via the control system; wherein the electric motor of the hydraulic pump can function as a generator; also comprising a combustion engine which is connected to the generator using a connectable and disconnectable coupling.

5. The mobile apparatus as claimed in claim 1, wherein at least one of said at least one energy storage units is positioned in the main frame; and/or wherein at least one of said at least one energy storage units is positioned in the rotatable sub-frame.

6. The mobile apparatus as claimed in claim 1, wherein the at least one energy storage unit for supplying energy to the at least one electric motor for the displacing means is positioned externally outside the main frame.

7. The mobile apparatus as claimed in claim 1, wherein the at least one of the energy storage units comprises any one or more of the following: a battery or a capacitor.

8. The mobile apparatus as claimed in claim 1, wherein the control system comprises a bus system.

9. The mobile apparatus as claimed in claim 1, wherein the at least one energy storage unit is coupled to the main frame via a front, a rear or a side thereof.

10. The mobile apparatus as claimed in claim 1, wherein the at least one energy storage unit is coupled to the main frame via an upper or underside thereof.

11. The mobile apparatus as claimed in claim 1, wherein the at least one energy storage unit is coupled to the rotatable sub-frame via a rear side of the sub-frame.

12. The mobile apparatus as claimed in claim 1, wherein a side of the mobile apparatus is configured to be coupled to an external energy source for charging one of the at least one energy storage unit.

13. A mobile apparatus comprising a main frame with displacing means, a sub-frame arranged rotatably relative to the main frame, wherein the rotatable sub-frame comprises operating instruments for a driver, an operating arm connected to the sub-frame, a first drive configured to drive the displacing means, a second drive configured to drive the operating arm, and a control system, connected to the operating instruments, for controlling the first and second drive, wherein a power take-off shaft configured to drive implements is arranged on the main frame, wherein the power take-off shaft is provided with a drive embodied as at least one electric motor and configured to be controlled via the control system; wherein the at least one electric motor for driving at least one power take-off shaft is provided with energy from at least one energy storage unit, a generator, a fuel cell, or a combination thereof.

14. The mobile apparatus as claimed in claim 13, also comprising a hydraulic pump configured to supply hydraulic energy, wherein the hydraulic pump is provided with a drive embodied as an electric motor and configured to be controlled via the control system; wherein the electric motor of the hydraulic pump can function as a generator; also comprising a combustion engine which is connected to the generator using a connectable and disconnectable coupling.

15. The mobile apparatus as claimed in claim 13, wherein at least one of said at least one energy storage units is positioned in the main frame; and/or wherein at least one of said at least one energy storage units is positioned in the rotatable sub-frame.

16. The mobile apparatus as claimed in claim 13, wherein the control system comprises a bus system.

17. The mobile apparatus of claim 13, wherein the first drive comprises at least one electric motor such that the first drive is substantially electrical; wherein the at least one electric motor for driving the power take-off shaft is provided with energy from at least one energy storage unit which is the same at least one energy storage unit for supplying energy to the at least one electric motor for the first drive of the displacing means.

18. The mobile apparatus as claimed in claim 13, wherein the control system is configured to adjust the direction of rotation of the at least one electric motor for driving the power take-off shaft, depending on a chosen travel direction of the mobile apparatus and/or the coupled implement.

19. A mobile apparatus comprising a main frame with displacing means, a sub-frame arranged rotatably relative to the main frame, wherein the rotatable sub-frame comprises operating instruments for a driver, an operating arm connected to the sub-frame, a first drive configured to drive the displacing means, a second drive configured to drive the operating arm, and a control system, connected to the operating instruments, for controlling the first and second drive, wherein the first drive comprises at least one electric motor such that the first drive is substantially electrical; said mobile apparatus further comprising at least one energy storage unit for storing and supplying electrical energy to the at least one electric motor and a fuel cell, said fuel cell being configured for supplying energy to the at least one energy storage unit.

20. The mobile apparatus of claim 19, wherein the fuel cell is placed in the main frame.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The above stated and other advantageous features and objects of the invention will become more apparent, and the invention better understood, on the basis of the following detailed description when read in combination with the accompanying drawings, in which:

(2) FIGS. 1-5 show schematic side and front views of different embodiments of the mobile apparatus according to the invention; and

(3) FIGS. 6-16 show block diagrams of different embodiments of the mobile apparatus according to the invention; and

(4) FIGS. 17-24 show schematic side and rear views of different embodiments of the invention.

DETAILED DESCRIPTION OF THE INVENTION

(5) FIG. 1 shows a mobile apparatus 1000 provided with main frame 1 on which wheels 4 are arranged. A location 6 for the driver in the form of a cab is arranged on main frame 1. Cab 6 is rotatable to limited extent relative to main frame 1. Also arranged on main frame 1 is an operating arm 100 with an implement 101. Main frame 1 is moreover provided with a lifting device 200 to which additional implements (not shown) can be coupled.

(6) In the embodiment of FIG. 2 caterpillar tracks 4 are arranged on the main frame as displacing means instead of wheels. FIG. 3 shows a variant of a mobile apparatus provided with caterpillar tracks.

(7) The embodiment in FIG. 4 is provided with a sub-frame 2 which is infinitely rotatable relative to main frame 1 by means of slip ring 400. The apparatus can comprise for this purpose an electric motor with suitable control, as will be described in more detail below. Cab 6 and operating arm 100 with implement 101 are arranged on sub-frame 2 and can thereby also rotate infinitely relative to main frame 1. Main frame 1 is also provided in this embodiment with a power takeoff shaft 204.

(8) FIG. 5 shows a front view of a mobile apparatus 1000, wherein sub-frame 2 is rotated relative to main frame 1. In this embodiment operating arm 100 is an articulated operating arm provided with an implement 101 for excavating.

(9) The construction of the different components of a mobile apparatus is described schematically in more detail in the following figures. It will be apparent that, when reference is for instance made to wheels 4 in the context of these figures, these can equally well be replaced by the caterpillar tracks as shown in FIGS. 2-4.

(10) With reference to FIG. 6, the driving of displacing means 4, in this variant in the form of wheels 4, takes place using an electric motor 3. Motor 3 drives a main drive shaft 41 which drives wheels 4 via suitable differentials and drive shafts 42. Electric motor 3 is electrically coupled to an energy storage in the form of a battery 5. In this embodiment battery 5 is coupled via an inverter 501 to electric motor 3. Control of electric motor 3 takes place via a command system 8. The driver or user of the mobile unit can give instructions to command system 8, for instance for the control of the drive means of displacing means 4, via operating instruments 7. In this embodiment operating instruments 7 are arranged in the cab of a mobile apparatus. Command system 8 can optionally be coupled via a controller 500 to electric motor 3, wherein the controller is configured to convert the control signals of command system 8 to suitable control signals for electric motor 3.

(11) The embodiment as shown in FIG. 7 differs from that of FIG. 6 in respect of the drive of displacing means 4. In this embodiment displacing means 4 are driven directly by an electric motor 3. Electric motor 3 is more specifically arranged directly on the shaft of a wheel 4. Although only one wheel 4 is provided with a drive in this embodiment, it will be apparent that each of the wheels can be provided with such a drive in the form of an electric motor 3, wherein each of these motors is connected to a or the battery 5 and command system 8, optionally via controllers 500, for control thereof.

(12) Shown for instance in FIG. 8 is that a rear electric motor 3a is provided which drives rear shaft 41a, which in turn drives the drive shafts 42a of rear wheels 4 via a suitable differential. The control of electric motor 3a again takes place via controller 500 and command system 8. Provided on the front side is a second electric motor 3b which drives front wheels 4 via front shaft 41b and drive shafts 42b. The front electric motor 3b is also coupled via its own controller 500 to command system 8 for the control thereof. The two motors 3a, 3b are coupled via inverters 501 to the same battery 5.

(13) Provided in the embodiment of FIG. 9 for charging battery 5 is a combustion engine 10 which is coupled via a coupling 19 to a generator 9. It is possible for coupling 19 to be integrated into generator 9 or combustion engine 10. Generator 9 is coupled to battery 5 via an inverter 501. Since in this variant combustion engine 10 serves only for charging battery 5 and not for driving of for instance the displacing means, the combustion engine can run at an ideal, high-efficiency rotation speed, wherein generator 9 converts this movement into electrical energy which is supplied via inverter 501 to battery 5.

(14) A variant is shown in FIG. 10. In this embodiment generator 9 is also coupled via the optional inverter 501 to electric motor 3. This makes it possible for the electricity generated by combustion engine 10 to be supplied directly, i.e. without interposing battery 5, to electric motor 3.

(15) FIG. 11 shows other means for charging battery 5 which can be used as alternative to or in combination with the combustion engine. Battery 5 can thus be charged using a fuel cell 11 and/or battery 5 can be charged using a charger 12 which can be coupled with a releasable connector 13a to an external energy source 13, for instance a (high-voltage) wall socket in a garage.

(16) FIG. 12 shows an embodiment provided with a power takeoff shaft 204. This power takeoff shaft 204 is driven by an electric motor 203. Electric motor 203 for power takeoff shaft 204 is in turn coupled via a controller 500 to command system 8 for the control of the power takeoff shaft 204. The electricity for electric motor 203 for power takeoff shaft 204 is again supplied by battery 5 via an inverter 501. The same battery 5 also supplies energy to electric motor 3 for driving the wheels 4. It is once again possible in this variant for battery 5 to be provided with energy by combustion engine 10 via a generator 9 (FIG. 13) and/or using a fuel cell 11 (FIG. 14).

(17) FIG. 15 shows the drive of power takeoff shaft 204 in isolation. In this embodiment electric motor 203 obtains energy via an inverter 501 coupled to a generator 9. Generator 9 here supplies electrical energy directly to electric motor 203. Generator 9 can be driven by a combustion engine (not shown). It is also possible for electric motor 203 to obtain energy directly from a fuel cell 11, see FIG. 16.

(18) FIG. 17 shows a hydraulic pump 300, for instance for driving the hydraulic operating arm 100. Hydraulic pump 300 is situated in this embodiment in main frame 1 and is connected via a generator 9 and coupling 19 to a combustion engine 10. Combustion engine 10 can here drive hydraulic pump 300 directly, wherein electrical energy is also generated by generator 9. This latter is connected for this purpose to a battery 305.

(19) In an embodiment it is however also possible that generator 9 can also serve as electric motor, for instance in the case that combustion engine 10 is switched off. Coupling 19 can for this purpose disconnect combustion engine 10 from the generator 9 acting as electric motor. Generator 9 acting as electric motor obtains energy from a battery 305 coupled thereto.

(20) In the variant of FIG. 18 the combination of combustion engine 10, coupling 19, generator 9 and hydraulic pump 300 is arranged in rotatable sub-frame 2. This is particularly advantageous when operating arm 100 is also arranged on rotatable sub-frame 2. Also shown is that main frame 1 is provided with a coupling 20 for a charger. This is located on the rear side of main frame 1 so that it can be easily coupled to a power supply, which can for instance be placed in a trailer behind the mobile apparatus.

(21) FIG. 19 shows that a single hydraulic pump 300 can be connected to a plurality of hydraulic valves 301 and 301′ using suitable hydraulic conduits 306. One valve 301 is for instance situated in the main frame for coupling to an implement, while a second valve 301′, for instance for an implement 101 on operating arm 100 or for operating arm 100 itself, is situated in sub-frame 2.

(22) The hydraulic conduit is then carried from hydraulic pump 300 in main frame 1 through slip ring 400 to valve 301′ in sub-frame 2. It will be apparent that a plurality of valves can be provided.

(23) Solely electrical driving of a hydraulic pump 300 is however also possible. An example hereof is shown in FIG. 20. A hydraulic pump 300 in sub-frame 2 is coupled here to an electric motor 303, which is in turn coupled to a suitable battery which is preferably also situated in sub-frame 2. Hydraulic pump 300 is coupled to a valve 301 arranged in sub-frame 2.

(24) It will be apparent that each of the components for controlling, such as electric motors 300, 303 and/or valves 301, 301′, are coupled in these embodiments to command system 8, for instance using suitable controllers 500 as also shown in the previous embodiments. The different components, for instance drive 3 of wheels 4, drive 203 of a power takeoff shaft 204 (FIG. 12) and drive 303 of hydraulic pump 300, can then be controlled using operating instruments 7 (see for instance FIG. 6). It is then particularly advantageous for the different components for controlling to be provided with sensors for measuring the different operating parameters, such as for instance temperature, (hydraulic) pressure, (relative) positions of drive shafts, and so on. The different controllers 500 can then transmit these measurements to command system 8 so that the components can be controlled with feedback.

(25) As stated, electric motors can be arranged both in main frame 1 and in sub-frame 2 for the purpose of driving different components. Batteries 5, 205, 305 which supply the energy for these electric motors can also be arranged in both main frame 1 and sub-frame 2. FIG. 21 shows for instance that a battery 5, 205, 305 is arranged on the underside of main frame 1, while a second battery 5, 205, 305 is arranged on the rear side of sub-frame 2. This battery 5, 205, 305 then at the same time serves as counterweight.

(26) FIGS. 22, 23 and 24 show different variants of the placing of batteries 5, 205, 305 in main frame 1. In the embodiment of FIG. 22 the battery can for instance be received in a receiving space 18 in main frame 1. The dimensions of receiving space 18 in main frame 1 correspond to the dimensions of the battery 5, 205, 305 to be accommodated. Shown in FIG. 23 is a battery 5, 205, 305 which is provided with an edge part 51 which in connected situation abuts against the underside 18b of main frame 1. Shown in FIG. 24 is a construction wherein battery 5, 205, 305 is situated on the one side of main frame 1 while several other components, such as combustion engine 10, coupling 19, generator 9 and fuel cell 11, are located on the other side. The coupling of charger 20 is arranged more centrally.

COMPONENTS

(27) 1. main frame 2. sub-frame 3. electric motor for driving displacement 4. tyre(s) or caterpillar track(s) 5. energy storage 6. location driver 7. operating instruments 8. command system 9. generator 10. combustion engine 11. fuel cell 12. charger 13. energy source outside mobile apparatus 19. coupling 20. coupling of charger 100. operating arm 101. implement on operating arm 200. lifting device 201. implement on lifting device 202. stabilizing device 203. electric motor for drive of power takeoff shaft 204. power takeoff shaft 205. energy storage 300. hydraulic pump 301. hydraulic valve 303. electric motor for hydraulic pump 305. energy storage 400. rotary joint/slip ring 500. controller or ECU or I/O unit 501. inverter or a converter

(28) The present invention is not limited to the shown embodiments but also extends to other embodiments falling within the scope of the appended claims.