Rotary Machine Having a Position Sensor

Abstract

A rotary machine, in particular electric motor, includes a position sensing means for sensing a rotational position of a pole wheel that is rotatable about an axis of rotation. The pole wheel has a circumferential edge, and the position sensing means has at least one first position sensor for sensing a change in a magnetic field, at least one magnetic element arranged on the pole wheel, and at least one circuit card on which electronic components are arranged. The first position sensor is arranged at least indirectly on the circuit card. The first position sensor extends at least partially into a space of the pole wheel that surrounded by the circumferential edge.

Claims

1. A rotary machine comprising: a pole wheel rotatable about an axis of rotation, the pole wheel having a circumferential edge; a position sensing device configured to sense a rotational position of the pole wheel, the position sensing device comprising: at least one first position sensor configured to sense a change in a magnetic field; at least one magnetic element arranged on the pole wheel; and at least one circuit card on which electronic components are arranged, the first position sensor being arranged at least indirectly on the circuit card, wherein the first position sensor extends at least partially into a space of the pole wheel that is surrounded by the circumferential edge.

2. The rotary machine according to claim 1, wherein the at least one circuit card defines a recess in which the circumferential edge of the pole wheel runs.

3. The rotary machine according to claim 2, wherein the recess is a milled-out recess defined in the at least one circuit card.

4. The rotary machine according to claim 2, wherein the recess is an annular recess.

5. The rotary machine according to claim 1, wherein the first position sensor extends into the pole wheel in a direction of the axis of rotation by a predefined length, and the predefined length is at least 1.0 mm.

6. The rotary machine according to claim 1, wherein the position sensing device includes at least one additional position sensor.

7. The rotary machine according to claim 1, wherein the at least one circuit card has a thickness that is greater than 1.5 mm and less than 5 mm.

8. The rotary machine according to claim 2, wherein the recess has a depth in a thickness direction of the at least one circuit card that is greater than 1 mm and less than 3 mm.

9. The rotary machine according to claim 1, wherein the at least one circuit card is of a multilayer structure.

10. The rotary machine according to claim 1, wherein the position sensing device further comprises a second position sensor arranged on a surface of the at least one circuit card that faces away from the pole wheel.

11. The rotary machine according to claim 1, wherein the rotary machine is an electric motor.

12. The rotary machine according to claim 7, wherein the thickness of the at least one circuit card is greater than 2.0 mm and less than 4 mm.

13. The rotary machine according to claim 12, wherein the thickness of the at least one circuit card is greater than 2.5 mm and less than 3.5 mm.

14. The rotary machine according to claim 13, wherein the thickness of the at least one circuit card is greater than 3.0 mm.

15. The rotary machine according to claim 8, wherein the depth is greater than 2.0 mm and less than 2.8 mm.

16. The rotary machine according to claim 15, wherein the depth is less than 2.5 mm.

17. A method for operating a rotary machine comprising: sensing, with a position sensing device, a rotational position of a pole wheel that is rotatable about an axis of rotation, the pole wheel having a circumferential edge, and the position sensing device including at least one first position sensor that senses a change in a magnetic field, at least one magnetic element arranged on the pole wheel, and at least one circuit card on which electronic components are arranged, the first position sensor arranged at least indirectly on the at least one circuit card and extending at least partially into a space of the pole wheel that is surrounded by the circumferential edge.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Further advantages and embodiments are evident from the appended drawings.

[0036] There are shown therein:

[0037] FIG. 1 a perspective view of a pole wheel and a printed circuit board;

[0038] FIG. 2 another perspective view, in which the circumferential edge of the pole wheel projects into a recess;

[0039] FIG. 3 a plan view, from above, of the circuit card with the pole wheel arranged thereon; and

[0040] FIG. 4 a plan view of the rear side of the circuit card shown in FIG. 3;

[0041] FIG. 5 a further representation of the pole wheel arranged on the printed circuit board;

[0042] FIG. 6 a sectional view of the representation shown in FIG. 5;

[0043] FIG. 7 a representation of the pole wheel; and

[0044] FIG. 8 a representation of the encoder cover.

DETAILED DESCRIPTION

[0045] FIG. 1 shows a circuit card 6, which here has a plurality of layers 66, 67 and 68. This circuit board in this case has a first surface 6a, which here faces to the right, and in particular in the direction of a pole wheel 2. In addition, the circuit card has a rear surface on which elements such as a control means (not shown) may also be arranged.

[0046] The pole wheel 2 rotates with respect to an axis of rotation D and has in its interior (not shown) at least one magnetic element, and in particular a permanent magnet. The reference 22 denotes a circumferential edge of the pole wheel.

[0047] Realized in the circuit card 6 there is a circumferential recess 62, and in particular a milled recess. The reference 64 denotes an island-like region (not milled-out) that is completely surrounded by the recess 62. Arranged on this island-like region 64 there is a multiplicity of position sensors 42. In this case, these are evenly distributed here in a circumferential direction.

[0048] The reference B denotes a radial width of this recess. The circumferential edge 22 engages in this recess 62.

[0049] FIG. 2 shows a representation in which the pole wheel runs in the recess 62, and in which, in particular, the circumferential edge 22 runs in this recess.

[0050] The reference 24 denotes an interior space of the pole wheel, in which, in particular, the permanent magnets are also arranged. It can be seen that the position sensors 42 project into this space and are thus arranged close to the permanent magnets of the pole wheel.

[0051] The reference T denotes the thickness of the printed circuit board, and the reference 72 denotes a heat sink. Preferably, the width B of the recess is configured in such a manner that the circumferential edge is also spaced, in the plane of the printed circuit board, at least 0.2 mm, preferably at least 0.3 mm, preferably at least 0.4 mm and preferably at least 0.5 mm from the circumferential edge of the recess. There is also a corresponding spacing in relation to the island on which the position sensors are arranged.

[0052] FIG. 3 shows a plan view of the printed circuit board and the pole wheel 2. Here again, the position sensors can be seen, which are arranged in the circumferential direction of the axis of rotation D. The reference 65 denotes an electronic component that is arranged on the printed circuit board, specifically on the region of the printed circuit board that has not been machined or milled-out.

[0053] FIG. 4 shows a plan view of the printed circuit board from below. Another position sensor means can be seen here, which is also suitable for sensing magnetic fields, but in this case while the device is at a standstill and/or in a de-energized operating state. For this purpose, a battery (not shown) is provided, which enables operation of this position sensor 46 even when the pole wheel (not shown) is at a standstill.

[0054] Here also in this case, the position sensor means 46 is arranged within the region that lies within a cross-section of the pole wheel. The reference 67 denotes a central processor means that serves to evaluate the data of the individual position sensors.

[0055] FIG. 5 shows a further representation to illustrate the disclosure. Here again the pole wheel is shown, and here also a magnetic element 24, such as a permanent magnet, provided within the pole wheel, can be seen. Also shown is the island-like region that is arranged within the pole wheel and can thus be brought close to the magnetic element. The circumferential edge and a circumferential edge of the magnetic element 24 are located within the recess 62. It can be seen that an end face, or circumferential edge, of the magnetic element 24 also projects into the recess.

[0056] The reference 12 denotes a first housing part, and the reference 14 denotes a second housing part. The reference 16 denotes an encoder cover, and the reference 52 denotes a seal. The reference 15 denotes an energy storage means such as a battery, which serves to supply the above-mentioned further position sensor.

[0057] FIG. 6 shows a sectional view of a device according to the disclosure. Also shown here is a shaft 18 on which the pole wheel 2 is arranged. This shaft 18 is rotatably mounted with respect to a housing by means of a bearing 19. The reference D denotes the axis of rotation with respect to which the pole wheel 2 is rotatably mounted. The above-mentioned position sensors project into the pole wheel in the direction of this axis of rotation.

[0058] FIG. 7 shows a representation of the pole wheel 2. The magnetic element 24 is also shown again here. This magnetic element realizes a circumferential edge 24a, which also projects into the recess 62. The reference 26 denotes a carrier, or hub, of the pole wheel. On the one hand, this carrier may be attached to the (motor) shaft, and on the other hand this carrier also serves to accommodate the magnetic element 24. The reference 28 denotes the space inside the pole wheel into which the position sensors project. The reference 32 denotes a base shield against which the magnetic element rests and/or is arranged. This base shield 32 is realized here in the form of a plate.

[0059] FIG. 8 shows a representation of the encoder cover 16, which here also accommodates a battery 15. The reference 17 denotes another printed circuit board.

[0060] The applicant reserves the right to claim all features disclosed in the application documents insofar as they are novel compared to the prior art, either individually or in combination. It is also noted that the individual figures also describe features that may be advantageous in themselves. Persons skilled in the art will immediately recognize that a particular feature described in a figure may also be advantageous without the adoption of further features from this figure. Furthermore, persons skilled in the art will recognize advantages may also result from a combination of a plurality of features shown in individual figures or in different figures.