ROTOR WITH PLASTIC HUB

Abstract

A rotor for an electric motor includes a hub, formed of a plastic material, having a bore and a resilient hub finger; a magnetic ring rotationally connected to the hub; and a fixed axle arranged in the bore for receipt of a radial force applied by the resilient hub finger to facilitate rotation of the hub about the fixed axle.

Claims

1. A rotor for an electric motor, the rotor comprising: a hub, formed of a plastic material, having a bore and a resilient hub finger; a magnetic ring rotationally connected to the hub; and a fixed axle arranged in the bore for receipt of a radial force applied by the resilient hub finger to facilitate rotation of the hub about the fixed axle.

2. The rotor of claim 1, wherein the resilient hub finger extends substantially parallel with the fixed axle.

3. The rotor of claim 1, wherein the resilient hub finger is formed at one region of the hub to apply the radial force to the fixed axle.

4. The rotor of claim 1, wherein the resilient hub finger has a radially internal projection that engages the fixed axle.

5. The rotor of claim 1, wherein the resilient hub finger is formed in an axial end region of the hub to face towards an axial end of the hub which terminates the axial end region.

6. The rotor of claim 1, wherein the magnetic ring is arranged radially outside the resilient hub finger to at least partially axially cover the resilient hub finger.

7. The rotor of claim 1, wherein a portion of the hub is in the form of a bearing shell for the fixed axle.

8. The rotor of claim 7, wherein the bearing shell at least partially axially covers the resilient hub finger.

9. The rotor of claim 7, wherein the bearing shell forms a circle segment which covers between 185 degrees and 270 degrees.

10. The rotor of claim 9, wherein the bearing shell is formed with substantially a same radial spacing with respect to a center of the fixed axle as the resilient hub finger so that the resilient hub finger and the bearing shell form circle segments of a same circle.

11. The rotor of claim 10, wherein the radial spacing of the resilient hub finger from the center of the bore of the hub is slightly less than the radial spacing of the bearing shell from the centre of the bore so that the continuation/hub finger is pretensioned against the axle.

12. The rotor of claim 7, further comprising a tooth arrangement is formed on the hub in an axial toothed region of the hub, the toothed region arranged to not intersect an axial region of the resilient hub finger.

13. An actuator for a motor vehicle, the actuator comprising: an electrically commutated electric motor that includes a rotor having: a hub, formed of a plastic material, having a bore and a resilient hub finger; a magnetic ring rotationally connected to the hub; and a fixed axle arranged in the bore for receipt of a radial force applied by the resilient hub finger to facilitate rotation of the hub about the fixed axle.

14. The actuator of claim 13, electrically commutated electric motor further includes a fixed stator arranged radially externally around the magnetic ring.

15. The actuator of claim 13, wherein the resilient hub finger extends substantially parallel with the fixed axle.

16. The actuator of claim 13, wherein the resilient hub finger has a radially internal projection that engages the fixed axle.

17. The actuator of claim 13, wherein the magnetic ring is arranged radially outside the resilient hub finger to at least partially axially cover the resilient hub finger.

18. The actuator of claim 13, wherein a portion of the hub is in the form of a bearing shell for the fixed axle.

19. The actuator of claim 13, wherein: the bearing shell at least partially axially covers the resilient hub finger. the bearing shell is formed with substantially a same radial spacing with respect to a center of the fixed axle as the resilient hub finger so that the resilient hub finger and the bearing shell form circle segments of a same circle, and the radial spacing of the resilient hub finger from the center of the bore of the hub is slightly less than the radial spacing of the bearing shell from the centre of the bore so that the continuation/hub finger is pretensioned against the axle.

20. The actuator of claim 13, further comprising a tooth arrangement is formed on the hub in an axial toothed region of the hub, the toothed region arranged to not intersect an axial region of the resilient hub finger.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0019] The one or more embodiments of this disclosure will be illustrated by way of example in the drawings and explained in the description hereinbelow.

[0020] FIG. 1 shows a three-dimensional top view of a rotor, in accordance with one or more embodiments.

[0021] FIG. 2 shows a three-dimensional bottom view of the rotor of FIG. 1.

[0022] FIG. 3 shows a lateral sectional view of the rotor of FIG. 1 through the continuation/hub finger, according to the section A-A of FIG. 4.

[0023] FIG. 4 shows a bottom view of the rotor of FIG. 1 with the position of the section A-A.

[0024] FIG. 5 shows a detailed illustration of the detail X of FIG. 3.

DESCRIPTION

[0025] FIG. 1 shows an oblique top view of a rotor in accordance with one or more embodiments. It is possible to see the hub 1 is formed of a plastic material with an integrated tooth arrangement 7 and the magnetic ring 2 which is connected to the hub 1.

[0026] FIG. 2 shows an oblique bottom view of the rotor of FIG. 1. The hub 1 is, at the side facing away from the tooth arrangement 7, divided by slots 8. A side of a circular formation of the hub 1 thereby forms a fixed bearing shell 6 around the central bore 3 and at the opposing side of the circular formation, in another circumferential region, a finger-like continuation/hub finger 4 is produced. As a result of the geometric configuration of the continuation/hub finger 4, it is much more flexible compared with the bearing shell 6 and can be deflected under the action of pressure.

[0027] FIGS. 1 and 2 consequently show a rotor for an electric motor, comprising a hub 1 formed of a plastic material and which has a bore 3, a magnetic ring 2 which is connected to the hub 1 in a rotationally secure manner, a fixed axle (not illustrated) arranged in the bore 3 so that the hub 1 can rotate about the fixed axle.

[0028] In accordance with one or more embodiments, a portion of the hub 1 itself, i.e., integrally with respect to the hub 1, comprises a resilient continuation/hub finger 4 which applies a radial force to the fixed axle which is arranged in the bore 3. The continuation/hub finger 4 extends substantially parallel with the axle 3 and forms a boundary of the bore 3.

[0029] As can also be seen in FIG. 3, the continuation/hub finger 4 is formed in an axial end region of the hub 1 and faces in the direction towards an axial end of the hub 1 which terminates this axial end region.

[0030] The magnetic ring 2 is arranged radially outside the continuation/hub finger 4 and axially completely covers the continuation/hub finger 4.

[0031] As can be clearly seen in FIGS. 2 and 3, a portion of the hub 1 is in the form of a bearing shell 6 for the fixed axle. The bearing shell 6 is in this axial end region constructed to be of the same axial length as the continuation/hub finger 4, and therefore covers the continuation/hub finger 4 completely. The bearing shell 6 is formed substantially with the same radial spacing with respect to the centre of the axle as the continuation/hub finger 4 so that the continuation/hub finger 4 and the bearing shell 6 form circle segments of the same circle which are separated from each other by slots 8. The bearing shell 6 forms a circle segment which occupies approximately 250 degrees. The continuation/hub finger 4 forms a circle segment. This circle segment may occupy approximately from 10 to 40 degrees, in this instance approximately 15 degrees.

[0032] In an axial toothed region of the hub 1, a tooth arrangement 7 is formed on the hub 1, wherein the toothed region does not intersect with the axial region of the continuation/hub finger 4.

[0033] In the illustrated embodiment (see FIG. 3), the hub 1 has a cup-shaped formation on which the magnetic ring 2 is arranged radially externally and in which at the radially inner side the bearing shell 6 and the continuation/hub finger 4 are arranged. The base of this cup merges at the other axial end at which the continuation/hub finger 4 is not formed into a sleeve which continues the bearing shell 6 and which completely delimits the bore 3 circumferentially.

[0034] In the detailed view of FIG. 5, a projection 5 can be seen at the inner side of the continuation/hub finger 4 and forms the region which is in contact with the axle. The spacing b is configured to be less than the spacing a so that, when the rotor is pushed onto the axle, the continuation/hub finger 4 presses on the fixed axle with a small pre-tensioning. The radial spacing of the continuation/hub finger 4 from the centre of the bore 3 of the hub 1 is therefore slightly less than the radial spacing of the bearing shell 6 from the centre of the bore 3 so that the continuation/hub finger 4 is pretensioned against the fixed axle.

LIST OF REFERENCE SYMBOLS

[0035] 1 Hub [0036] 2 Magnetic ring [0037] 3 Bore [0038] 4 Continuation/hub finger [0039] 5 Projection [0040] 6 Bearing shell [0041] 7 Tooth arrangement [0042] 8 Slot [0043] a Spacing [0044] b Spacing