DRIVE WHEEL FOR A TRANSPORT TROLLEY, DRIVE SYSTEM WITH SUCH A DRIVE WHEEL AND TRANSPORT TROLLEY

Description

[0001] The present invention relates to a drive wheel for a transport cart, wherein the drive wheel comprises at least one wheel body rotatable about at least one wheel axle, at least one wheel housing unit supporting the wheel axle, and at least one first functional component that is at least partially in operative contact with the wheel body, as well as a drive system comprising such a drive wheel and a transport cart comprising a drive wheel and / or a drive system according to the invention.

[0002] Drive wheels are known from the prior art, for example from DE 20 2018 106 716 U1. It is proposed that a transport carriage have running rollers, wherein the running rollers are operatively connected to electric motors.

[0003] DE 20 2004 010 854 U1 also discloses a transport trolley which can be driven by means of drive wheels of the generic type in the form of fixed casters, which are operatively connected to electric motors. The electric motor is arranged at least partially within the fixed caster.

[0004] EP 2 623 391 A2 discloses a transport device for transporting a golf bag and at least one person. The transport device has drive wheels, with a motor designed as a hub motor, which is arranged in the area of ​​a rear axle of the transport device.

[0005] Finally, DE 101 05 614 A1 discloses a hospital bed with casters. It is proposed that an electric motor be provided to achieve a swiveling motion of a caster.

[0006] Further drive wheels are disclosed in the prior art in DE 103 43 857 A1, WO 2020 / 085213 A1, DE 38 26 933 A1 and US 2002 / 121823 A1.

[0007] However, the drive wheels known from the prior art have the disadvantage that they cannot be operated, or can only be operated inadequately, at maximum speeds and under high loads, for example, when driving up steep inclines on ramps or similar situations. Particularly in such extreme situations, where repeated acceleration and braking are necessary, malfunctions occur due to thermal overload of the drive wheel or its functional components.

[0008] It is therefore an object of the present invention to further develop the generic drive wheel in such a way that the disadvantages of the prior art are overcome, in particular a drive wheel is provided which enables continuous operation, or at least a longer operating time, even under loads at the limit, e.g. during long ramps and regular acceleration and braking, compared to drive wheels known from the prior art.

[0009] This problem is solved with regard to the drive wheel according to the characterizing portion of claim 1. Preferred embodiments are described in claims 2 to 10.

[0010] Furthermore, the invention provides a drive system for at least one transport carriage comprising at least one drive wheel according to the invention, preferably a plurality of drive wheels according to the invention as per claim 11. Further preferred embodiments of the drive system are described in claims 12 and 13.

[0011] Furthermore, the invention provides a transport cart comprising at least one drive wheel and / or a drive system according to the invention as defined in claim 14. A preferred embodiment of the transport cart is specified in claim 15.

[0012] The invention is therefore based on the surprising finding that by using a deliberately robust wheel housing unit, in particular in the form of an aluminum housing, thermal overload of the drive wheel or its functional components can be avoided, thereby increasing the load-bearing capacity of the drive wheel or a transport vehicle equipped with it.

[0013] By appropriately mounting a thermal energy-generating functional component, such as a drive unit, particularly in the form of an electric motor or individual components thereof, so that at least indirect thermal contact exists with the wheel housing unit, heat generated by the drive wheel, and especially the functional component, is dissipated. This results in increased load-bearing capacity of the drive wheel, and in particular increased torque for the drive wheel, over a longer period.

[0014] Furthermore, the design of the wheel housing unit allows various functional components of the drive wheel to be attached to it or brought into thermal contact with it. For example, a control unit, such as a power board of the control unit, can be integrated into the wheel housing unit and brought into thermal contact with it.

[0015] At least one filling device, such as a thermal pad, can be arranged between the functional component and the wheel housing unit to achieve optimal thermal coupling between the two. This ensures the best possible heat transfer from the functional component to the wheel housing unit.

[0016] This power board or output stage can then be operated in its maximum power range for a longer period of time without overheating, compared to drive wheels known from the state of the art.

[0017] Another functional component that can come into thermal contact with the wheel housing unit is, for example, a brake resistor. This can be attached directly to the wheel housing unit, in particular to a main body of the wheel housing unit. The wheel housing unit can also be constructed in such a way that the component is attached indirectly to the wheel housing unit itself, or indirectly to the main body of the wheel housing unit via another housing component, such as an electronics cover, which is also thermally conductive.

[0018] This allows braking energy to be quickly dissipated from the heat source in the form of the braking resistance and transferred to the wheel housing unit. In this way, longer braking cycles are possible compared to conventional drive wheels.

[0019] The inventors have further recognized that although the wheel housing unit increases the mass of the system, the associated disadvantages are more than compensated for by the fact that the wheel housing unit can be used as a thermal energy storage device.

[0020] The thermal energy generated by the drive wheel's functional components can thus be quickly dissipated and absorbed in the wheel housing unit, preventing overheating of the functional components or the drive wheel itself. The heat energy stored in the wheel housing unit can then be transferred to a supporting structure of the transport vehicle or to the surrounding air.

[0021] The transfer of heat energy from the respective functional component to the wheel housing unit, and the associated possibility of operating the drive wheel at higher power levels or for longer periods, further leads to an increase in the transport vehicle's travel speed. Surprisingly, the inventors discovered that this advantageous increase in travel speed also increases the dissipation of heat energy from the wheel housing unit to the environment, thus enabling even better thermal energy dissipation.

[0022] To enhance this effect, it is particularly preferred that the wheel housing unit has a surface structure, especially in the form of cooling fins or ribs. It can also be provided that a forced circulation of ambient air is generated around the wheel housing unit by means of a fan device, thus achieving improved heat dissipation from the wheel housing unit. Furthermore, this fan device can achieve or support better dissipation of thermal energy from other (secondary) functional components of the drive wheel, which are not in direct thermal contact with the wheel housing unit, especially the main body and / or the housing component, preferably by convection.

[0023] At the same time, the drive wheel according to the invention enables a compact design in combination with a direct drive. This allows, for example, installation heights of only 150 mm to be achieved, preferably with a simultaneous load-bearing capacity of, for example, at least 100 kg, preferably at least 250 kg, per drive wheel. When using two drive wheels, a load-bearing capacity of, for example, at least 200 kg or 500 kg is thus achieved, while simultaneously achieving a drive thrust of, for example, more than 30 daN (30 decanewtons). This makes it possible to traverse even long ramps with maximum drive force and enables continuous, regular acceleration and braking. This means, in particular, that transport trolleys with a maximum load of, for example, 200 kg or 500 kg can be used with this drive wheel.500 kg can be optimally supported, and even reserves are provided for acceleration and braking. The masses mentioned above are merely examples to illustrate the scope of the invention; applications with drive wheel load capacities of 5 tons and more are also conceivable.

[0024] The drive wheel according to the invention is particularly preferably used in a drive system which, in addition to the drive wheels, comprises other components. Preferably, this system is an open / flexible system in which individual components can be attached to variable transport trolleys in various combinations and serve to support the drive of the transport trolley. In other words, the system can be designed modularly.

[0025] In a preferred embodiment, the drive system comprises two drive wheels according to the invention, which are in particular designed as fixed casters and are integrated into the corresponding functional components in the form of motor control electronics and a motor. These are connected to a control device, which may in particular be designed in the form of an electronics box with a power supply unit, such as a battery unit.

[0026] To enable a user to control the drive wheels, a human-machine interface is provided, for example in the form of a sensor handle with force detection and hand detection.

[0027] The drive wheel or drive system according to the invention thus overcomes the problem of heat generation in drive motors and motor power electronics known from the prior art. In particular, the invention enables the efficient dissipation of the very high amount of energy generated during numerous starts, ramp drives, and braking cycles. Specifically, the invention prevents a reduction in efficiency due to the generated heat energy and avoids overheating, for example, of a power stage, when subjected to pulse-width modulation signals (PWM signals).

[0028] Further features and advantages of the invention will become apparent from the following description, the preferred embodiment of which is explained with reference to exemplary figures.

[0029] It shows: Figure 1 an exploded view of a drive wheel according to the invention; Figure 2a first cross-sectional view of the drive wheel of the Figure 1 ; Figure 3 a second cross-sectional view of the drive wheel of the Figures 1 and 2 ; Figures 4a to 4c Cross-sectional views through different levels of the drive wheel of the Figures 1 to 3 ; and Figure 5 a monitoring of individual components of a drive system according to the invention.

[0030] In Figure 1 Figure 1 shows an exploded view of a drive wheel 1 according to the invention. The drive wheel comprises a wheel body 3 on the circumference of which a running surface 5 is arranged. The wheel body 3 is rotatably mounted about a wheel axle 7. The wheel axle 7 in turn is supported on a wheel housing unit 9, which in this embodiment is designed as a solid aluminum pressure element. The wheel housing unit 9 has a main body 10.

[0031] Within the wheel body 3, a first drive unit 11, which partially forms a first functional component, is arranged. The drive unit 11 forms an electric motor and comprises a rotor 13, which is connected to the wheel body 3, in particular arranged to prevent rotation, and which forms a second functional component and has a plurality of permanent magnets.

[0032] Within the rotor 13, a stator 15, forming a further first functional component, is arranged, which is fixed in position relative to the wheel housing unit 9, in particular the main body 10.

[0033] The drive unit 11 allows the wheel body 3 to be rotated around the wheel axle 7. The stator 15 is connected to the wheel housing unit 9 via fastening elements 17 in the form of screws. The screws 17 also ensure a thermal connection between the stator 15 and the wheel housing unit 9.

[0034] On the side of the wheel housing unit 9 facing away from the stator 15, a further first functional component in the form of a control unit 19 is arranged. A filling device in the form of a thermal pad 21 is arranged between the control unit 19 and the main body 10 of the wheel housing unit 9. The thermal pad 21 is electrically insulating, but ensures the best possible thermal connection between the control unit 19 and the main body of the wheel housing unit 9. In particular, the thermal pad 21 prevents thermally insulating air inclusions from forming between the wheel housing unit 9 and the control unit 19, which would negatively affect heat transfer from the control unit 19 to the wheel housing unit 9.

[0035] On the side of the wheel housing unit 9 facing away from the wheel body 3, a sealing disc 23 and a housing component in the form of a cover 25 are arranged. This cover protects the control unit 19 from moisture. Furthermore, the cover 25 is in thermal contact with another first functional component of the drive wheel 1, namely a braking resistor 27. The cover 25 is a housing component of the multi-part wheel housing unit 9 and, like the main body 10 of the wheel housing unit 9, comprises a thermally conductive material, so that heat energy generated at the braking resistor 27 can be dissipated to the housing component in the form of the cover 25 and from there to the main body 10 of the wheel housing unit 9.

[0036] Finally, the drive wheel includes fastening elements 29 for attaching the cover 25 to the main body of the wheel housing unit 9 and for supporting the transfer of thermal energy to the main body 10. Furthermore, fastening elements 31 for connecting the wheel body 3 to the wheel axle 7 and a cover cap 32 are provided.

[0037] In the Figures 2 and 3 Different cross-sectional views of the drive wheel 1 are shown. In particular, Figures 2 and 3 As can be seen, a bearing element 33, comprising a ball bearing, is arranged in the area between the wheel axle 7 and the wheel body 3. This ensures that the wheel body is essentially freely rotatable about the wheel axle 7. As the Figures 2 and 3Furthermore, it can be seen that the rotor comprises 13 permanent magnets 35, as well as a rotor core 36 comprising at least one rotor lamination, which are connected in a rotationally secure manner to the wheel body 3 which is rotatable about the wheel axis 7.

[0038] Opposite the rotor 13, and in particular the permanent magnet 35, the stator 15 is arranged. The stator 15 comprises electromagnetic windings 37 and a stator core 38 comprising at least one stator lamination, wherein the windings preferably surround at least part of the stator core 38. By appropriately controlling the winding 37, in particular by means of PWM signals, it is possible to drive the wheel body 3 to rotate about the wheel axis 7.

[0039] In the illustrated embodiment, the drive wheel 1 is designed as a swivel caster. In other embodiments, it is also conceivable that the drive wheel additionally has a pivot axis which runs essentially perpendicular to the wheel axis 7. A forced rotation of the wheel body about a pivot axis is then possible via a second drive unit (not shown). It is provided that the second drive unit, or its functional components, is also in thermal contact with the wheel housing unit 9, in particular the main body and / or housing components, so that optimal dissipation of thermal energy from the second drive unit is enabled.

[0040] In the Figures 4a to 4cVarious cross-sectional views through different levels of the drive wheel 1 are shown. As can be seen from these, the control unit 19 is connected to the wheel housing unit 9, in particular the main body 10, via an optional thermal pad 21. Furthermore, in Figure 4b It is shown that the brake resistor 27 is also in thermal contact with the cover 25 or the wheel housing unit 9 via a corresponding optional thermal pad 39 and / or optional thermal paste.

[0041] This ensures the best possible dissipation of heat energy from the first functional components of the drive wheel 1 to the wheel housing unit 9.

[0042] In Figure 5Finally, a perspective view of the individual components of a drive system 41 according to the invention is shown. In addition to two drive wheels 43, 45 designed as fixed casters according to the invention, the drive system 41 comprises a human-machine interface in the form of a sensor handle 47. The sensor handle 47 is connected to an electronics box 49, which represents a control device, via connections not shown. The electronics box 49 includes, in particular, a power supply unit in the form of a battery. The drive system 41 enables a user to input commands via the sensor handle 47. These commands are transmitted as control commands via cables not shown or by means of wireless connections such as WLAN, Bluetooth, or the like to the drive wheels 43, 45, in particular their control units or drive devices.In alternative embodiments not shown, it may be provided that the inputs are first directed to the control device or electronics box 49 and converted there into control commands, or that control commands are generated in the control device or electronics box and passed on via connecting lines not shown to the control units or drive devices in the drive wheels 43, 45, in particular their control units or drive devices.

[0043] The features disclosed in the foregoing description, in the claims and in the figures can be essential to the invention in the various embodiments, both individually and in any combination. Reference symbol list

[0044] 1 Drive wheel 3 Wheel body 5 Running surface 7 Wheel axle 9 Wheel housing unit 10 Main body 11 Drive unit 13 Rotor 15 Stator 17 Screw 19 Control unit 21 Thermal pad 23 Sealing washer 25 Cover 27 Brake resistor 29 Fastener 31 Fastener 32 Cover cap 33 Bearing element 35 Permanent magnet 36 Rotor core 37 Winding 38 Stator core 39 Thermal pad 41 Drive system 43 Drive wheel 45 Drive wheel 47 Sensor handle 49 Electronics box

Claims

1. A drive wheel (1, 43, 45) for a transport trolley, wherein the drive wheel (1, 43, 45) comprises - at least one wheel body (3) which can be rotated about at least one wheel axle (7), - at least one wheel housing unit (9) which supports the wheel axle (7), and - at least one first functional component, which is operatively connected to the wheel body (3) at least in part, wherein the wheel housing unit (9) is connectable to at least one support structure of the transport trolley and is in thermal contact with at least a part of the first functional component, wherein thermal energy is able to be carried away from the first functional component by means of the wheel housing unit, characterized in that, in a first alternative, (i) the first functional component comprises at least one braking resistor (27) and / or at least one control unit (19) at least in regions, and wherein the drive wheel also comprises at least one filling element (21, 39), wherein the filling element is arranged in at least one intermediate space between the first functional component (19, 27) and the wheel housing unit (9), and / or wherein the filling element is in thermal contact with the wheel housing unit (9) and the first functional component, and wherein the filling element (21, 39) has a thermally conductive effect; or characterized in that, in a second alternative, (ii) at least one first drive unit (11) forming at least partly the first functional component is arranged inside the wheel body (3), wherein the first drive unit (11) forms an electric motor and comprises a rotor (13) that is connected to the wheel body (3) and forms a second functional component having a plurality of permanent magnets, wherein inside the rotor (13) a stator (15) is arranged that forms a further first functional component and is arranged to be stationary relative to the wheel housing unit (9) and wherein the stator (15) is connected to the wheel housing unit (9) by means of fastening elements (17) in the form of screws, wherein the fastening elements (17) ensure a thermal connection between the drive unit (11) and the wheel housing unit (9).

2. The drive wheel according to claim 1, first alternative (i), characterized in that the drive wheel (1) comprises at least one tread (5) that surrounds the wheel body (3) at least in regions.

3. The drive wheel according to claim 1, first alternative (i), or 2, characterized in that the first functional component comprises, at least in regions, at least one, in particular electrical, first drive unit (15), preferably for rotationally driving the wheel body (3), in particular about the wheel axle (7), at least one, in particular electrical, second drive unit, preferably for pivoting the wheel body (3) and / or the wheel housing unit (9) about at least one pivot axis, at least one energy-storage unit, such as a battery and / or an accumulator, in particular for controlling the first drive unit (15) and / or the second drive unit, at least one stator (15), at least one winding, at least one electromagnet, at least one stator lamination, and / or at least one stator core.

4. The drive wheel according to claim 3, characterized in that the pivot axis extends in a direction perpendicular to the wheel axle (7) at least in regions, the pivot axis and the wheel axle (7) intersect, and / or the pivot axis and the wheel axle (7) extend so as to be skewed relative to one another.

5. The drive wheel according to claim 1, first alternative (i), and / or according to any one of the preceding claims 2 to 4, characterized in that the wheel body (3) comprises, at least in regions, at least one second functional component (13), which is operatively connected to and / or in thermal contact with the first functional component (15), in particular the first drive unit (11), the second drive unit, the stator (15), the winding (37), the electromagnet, the stator lamination, and / or the stator core, in particular comprising at least one permanent magnet, at least one rotor, at least one rotor lamination, at least one rotor core, and / or at least one permanent magnet.

6. The drive wheel according to claim 1, first alternative (i), and / or according to any one of the preceding claims 2 to 5, characterized in that the filling element is arranged at least in an intermediate space between the first functional component (19, 27) and the wheel housing unit (9) and between the second functional component and the wheel housing unit (9) and / or in that the filling element (21, 39) is in thermal contact with the wheel housing unit (9), the first functional component, and the second functional component, and / or wherein the filling element (21, 39) preferably comprises at least one heat-conducting paste, at least one heat-conducting pad (21, 39), and / or at least one heat-conducting foil, wherein the filling element (21, 39) in particular has an electrically insulating effect.

7. The drive wheel according to claim 1, first alternative (i), and / or according to any one of the preceding claims 2 to 6, characterized in that the wheel housing unit (9) has, at least in regions, at least one surface structure, preferably comprising at least one cooling rib and / or at least one cooling fin, and / or comprises at least one fan apparatus, in particular for generating forced circulation of ambient air around the wheel housing unit (9), the first functional component (11, 15, 19, 21), the second functional component (13), the wheel body (3), and / or the wheel axle (7).

8. The drive wheel according to claim 1, first alternative (i), and / or according to any one of the preceding claims 2 to 7, characterized in that the wheel housing unit (9) comprises, at least in regions, aluminum, aluminum oxide, aluminum nitride, copper, gray iron, cast steel, steel, at least one zinc alloy, at least one compound at least partially comprising at least one metal material and / or die-cast aluminum, and / or thermal energy can be conducted to the support structure by means of the wheel housing unit (9), can be released to the ambient air, and / or can be stored in the wheel housing unit (9).

9. The drive wheel according to any one of the preceding claims, characterized in that (i) with reference to claim 1, alternative (i), a plurality of first functional components (11, 15, 19, 27) are present, (ii) a plurality of second functional components are present, (iii) the wheel housing unit (9) is constructed in multiple parts, in particular has at least one main body (10) and at least one housing component (25) that is connectable to the main body (10), wherein thermal energy in particular is able to be transmitted from the first functional component (27), the second functional component, and / or at least one of the first functional components (11, 15, 19, 27) and / or second functional components to the main body (10) by means of the housing component (25), and / or (iv) thermal energy can be transmitted by means of at least one connection element, fastening element (29), and / or transmission element that interconnects the housing component (25), the main body (10), the first functional component, and / or the second functional component.

10. The drive wheel according to any one of the preceding claims, characterized in that the wheel housing unit (9) forms, at least in regions, at least one wheel fork, at least one wheel support, and / or at least one wheel bracket, and / or the drive wheel (1) forms at least one fixed castor, at least one swivel castor, at least one positively steered swivel castor, and / or at least one freely pivotable swivel castor.

11. A drive system for at least one transport trolley, comprising at least one drive wheel (1, 43, 45), preferably a plurality of drive wheels (43, 45), according to any one of the preceding claims, wherein the drive system (41) further comprises at least one human-machine interface (47), at least one energy-supply apparatus (49), and / or at least one control device (49) that is at least indirectly operatively connected to the drive wheel (43, 45) and / or drive wheels (43, 45).

12. The drive system according to claim 11, characterized in that the human-machine interface comprises at least one sensor handle (47), at least one touch-screen display, at least one voice control unit, at least one gesture control unit, at least one wireless interface, and / or at least one traction switch, and / or control commands can be relayed to the drive wheel (43, 45) or drive wheels (43, 45), preferably the functional component (19), in particular the first functional component, the second functional component, and / or the control unit (19), in particular on the basis of inputs preferably made via the human-machine interface (47) and / or in a manner generated by means of the control device.

13. The drive system according to any one of claims 11 or 12, characterized in that, by means of the energy-supply apparatus, which the control device preferably comprises at least in regions, the drive wheel (43, 45) or drive wheels (43, 45), the human-machine interface (47), the control unit (19), the first functional component, the second functional component, the first drive unit, the second drive unit, the control device, and / or at least one electronics box (49) can be supplied with energy, and / or the energy-supply apparatus comprises at least one accumulator, at least one battery, at least one solar cell, at least one fuel cell, and / or at least one thermovoltaic element, which is preferably in thermal contact with the wheel housing unit.

14. A transport trolley comprising at least one drive wheel according to any one of claims 1 to 12 and / or a drive system according to any one of claims 11 to 13.

15. The transport trolley according to claim 14, characterized in that the transport trolley is designed, at least in regions, as a trailer, a tool trolley, and / or a support rack for at least one machine, such as at least one fan and / or at least one generator.