GEARED MOTOR WITH IMPROVED ANGULAR POSITION SENSING AND VEHICLE WITH SUCH A MOTOR

Abstract

A geared motor includes a gearbox with an input shaft, an electric motor with a rotor, wherein the rotor is coupled to or mounted on the input shaft of the gearbox at a first side of the input shaft. A position indicator is designed to indicate an angular position of the rotor. In detail, the position indicator is mounted on the input shaft of the gearbox at a second side vis-à-vis of its first side. Moreover, a geared vehicle may include such a geared motor.

Claims

1. Geared motor, comprising a gearbox with an input shaft, an electric motor with a rotor, wherein the rotor is coupled to or mounted on the input shaft of the gearbox at a first side of the input shaft, and a position indicator, which is designed to indicate an angular position of the rotor, wherein the position indicator is mounted on the input shaft of the gearbox at a second side vis-à-vis of its first side.

2. Geared motor as claimed in claim 1, wherein the position indicator is embodied as a magnet.

3. Geared motor as claimed in claim 1, wherein the position indicator is covered by a cap, which seals the housing of the gearbox.

4. Geared motor as claimed in claim 3, wherein the cap is made of plastic.

5. Geared motor as claimed in claim 1, wherein it comprises a position sensor, which is designed to detect the angular position of the rotor based on the angular position of the position indicator.

6. Geared motor as claimed in claim 1, wherein it comprises a power converter, which is arranged at the second side of the input shaft of the gearbox.

7. Geared motor as claimed in claim 6, wherein the position sensor is arranged within a housing of the power converter.

8. Vehicle having at least two axles, at least one of which is driven, wherein said driven is provided at least partially or intermittently by the geared motor according to claim 1.

9. Geared motor as claimed in claim 2, wherein the position indicator is covered by a cap, which seals the housing of the gearbox.

10. Geared motor as claimed in claim 2, wherein it comprises a position sensor, which is designed to detect the angular position of the rotor based on the angular position of the position indicator.

11. Geared motor as claimed in claim 2, wherein it comprises a power converter, which is arranged at the second side of the input shaft of the gearbox.

12. Vehicle having at least two axles, at least one of which is driven, wherein said driven is provided at least partially or intermittently by the geared motor according to claim 2.

13. Geared motor as claimed in claim 3, wherein it comprises a position sensor, which is designed to detect the angular position of the rotor based on the angular position of the position indicator.

14. Geared motor as claimed in claim 3, wherein it comprises a power converter, which is arranged at the second side of the input shaft of the gearbox.

15. Vehicle having at least two axles, at least one of which is driven, wherein said driven is provided at least partially or intermittently by the geared motor according to claim 3.

16. Geared motor as claimed in claim 4, wherein it comprises a position sensor, which is designed to detect the angular position of the rotor based on the angular position of the position indicator.

17. Geared motor as claimed in claim 4, wherein it comprises a power converter, which is arranged at the second side of the input shaft of the gearbox.

18. Vehicle having at least two axles, at least one of which is driven, wherein said driven is provided at least partially or intermittently by the geared motor according to claim 4.

19. Geared motor as claimed in claim 5, wherein it comprises a power converter, which is arranged at the second side of the input shaft of the gearbox.

20. Vehicle having at least two axles, at least one of which is driven, wherein said driven is provided at least partially or intermittently by the geared motor according to claim 5.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0014] The invention now is described in more detail hereinafter with reference to particular embodiments, which the invention however is not limited to.

[0015] FIG. 1 a schematic cross sectional view of an exemplary geared motor and

[0016] FIG. 2 shows a schematic view of an electric vehicle.

DETAILED DESCRIPTION

[0017] Generally, same parts or similar parts are denoted with the same/similar names and reference signs. The features disclosed in the description apply to parts with the same/similar names respectively reference signs. Indicating the orientation and relative position is related to the associated figure.

[0018] FIG. 1 shows a schematic cross sectional view of an exemplary geared motor 1, which comprises a gearbox 2, an electric motor 3 and an optional power converter 4.

[0019] The gearbox 2 comprises a housing 5, a multitude of bearings, of which two are shown in FIG. 1—bearings 6 and 7—arranged in the housing 5, an input shaft 8 supported by the bearings 6 and 7, a pinion 9 mounted on the input shaft 8 and a gear wheel 10 engaging with the pinion 9 and being mounted on to a further shaft of the gearbox 2 (not shown).

[0020] The electric motor 3 comprises a housing 12, a stator 13 arranged in the housing 13, wherein the stator 13 comprises a stator lamination stack 14 with stator windings 15 arranged therein, a bearing 16, a rotor shaft 17 supported by the bearing 16 and the input shaft 8 of the gearbox 2 and a rotor 18 mounted on the rotor shaft 17, wherein the rotor 18 comprises a rotor lamination stack 19 with rotor magnets 20 arranged therein.

[0021] In the example of FIG. 1, the rotor 18 is coupled to the input shaft 8 of the gearbox 2 via the rotor shaft 17 at a first side of the input shaft 8. However, in another embodiment, the input shaft 8 may be longer, and the rotor 18 may be mounted on the input shaft 8.

[0022] In addition, the geared motor 1 (in detail the gearbox 2) comprises a position indicator 21, which is designed to indicate an angular position of the rotor 18 and which is mounted on the input shaft 8 of the gearbox 2 at a second side vis-à-vis of the first side on the input shaft 8, i.e. vis-à-vis of the electric motor 3.

[0023] In this example, the position indicator 21 is embodied as a magnet and covered by a cap 22 made of plastic, which seals the housing 5 of the gearbox 2. Although this is an advantageous solution, the position indicator 21 may also embodied in another way, and the cap 22 may be made of a different material, for example of stainless steel or aluminum.

[0024] The optional power converter 4 comprises a housing 23, a printed circuit board 24, a position sensor 25, which is mounted on the printed circuit board 24 and which is designed to detect the position of the angular position of the rotor 18 based on the angular position of the position indicator 21, and further electronic parts 26 mounted on the printed circuit board 24. In this example, the position sensor 25 is arranged within the housing 23 of the power converter 4. Although this is an advantageous solution, the position indicator 21 may also be arranged out of the housing 23 of the power converter 4 and displaced from the printed circuit board 24 thereof.

[0025] As is visible in FIG. 1, the power converter 4 is arranged at the second side of the input shaft 8 of the gearbox 2 and thus vis-à-vis of the electric motor 3. Hence, there results a kind of a T-arrangement, the advantage of which particularly is visible in FIG. 2.

[0026] FIG. 2 shows an electric vehicle 27, which comprises the geared motor 1 with a gearbox 2, an electric motor 3 and a power converter 4 as outlined above. The geared motor 1 is mechanically coupled to wheels 29 of the electric vehicle 27 by means of side shafts 28. The electric motor 3 may be provided for powering the electric vehicle 27 permanently in a pure electric car or intermittently, e.g. in combination with a combustion engine in a hybrid car.

[0027] During operation, the position indicator 21 causes a rotating magnetic field at the second end of the input shaft 8, which is sensed by the position sensor 25 in a contactless manner through the cap 22. Advantageously, the position of the rotor 18 is directly available in the power converter 4 without additional cabling. Because the position indicator 21 is relatively far away from the electric motor 3, the rotating magnetic field caused by the position indicator 21 is little influenced by the electromagnetic field caused by the electric motor 3. Both allow for a strong and clear position signal. In addition, the available space in the electric vehicle 27 is used in an advantageous way so that the gearbox 2 can be arranged in the center axis or almost in the center axis of the electric vehicle 27. In turn, the side shafts 28 can have the same length without further measures what is advantageous for the suspension of the electric vehicle 27 and its driving characteristics.

[0028] It is noted that the invention is not limited to the embodiments disclosed hereinbefore, but combinations of the different variants are possible. In reality, the geared motor 1 and the electric vehicle 27 may have more or less parts than shown in the figures. Moreover, the description may comprise subject matter of further independent inventions.

[0029] It should also be noted that the term “comprising” does not exclude other elements and the use of articles “a” or “an” does not exclude a plurality. Also elements described in association with different embodiments may be combined. It should also be noted that reference signs in the claims should not be construed as limiting the scope of the claims.

LIST OF REFERENCE NUMERALS

[0030] 1 geared motor [0031] 2 gearbox [0032] 3 electric motor [0033] 4 power converter [0034] 5 housing of gearbox [0035] 6 bearing [0036] 7 bearing [0037] 8 input shaft [0038] 9 pinion [0039] 10 gear wheel [0040] 12 housing of electric motor [0041] 13 stator [0042] 14 stator lamination stack [0043] 15 stator winding [0044] 16 bearing [0045] 17 rotor shaft [0046] 18 rotor [0047] 19 rotor lamination stack [0048] 20 rotor magnet [0049] 21 position indicator [0050] 22 cap [0051] 23 housing of power converter [0052] 24 printed circuit board [0053] 25 position sensor [0054] 26 electronic parts [0055] 27 electric vehicle [0056] 28 side shaft [0057] 29 wheel