STATOR CORE FOR AN ELECTRONICALLY COMMUTATED DIRECT CURRENT MOTOR AND METHOD FOR PRODUCING A STATOR

• US 20160164351A1
• Filed: 02/11/2016
• Published: 06/09/2016
• Est. Priority Date: 08/21/2013
• Status: Active Grant

• Current Assignee: Buhler Motor GmbH
• Original Assignee: B?Hler Motor GmbH
• Inventors: Weiske, Klaus
• Granted Patent: US 9,780,607 B2
• Time in Patent Office: Days
• CPC Class Codes: H02K 1/146 consisting of a generally annular yoke with salient poles
• CPC Class Codes: H02K 1/148 Sectional cores H02K1/141 takes precedence
• CPC Class Codes: H02K 15/022 with salient poles or claw-shaped poles
• CPC Class Codes: H02K 15/095 by laying conductors around salient poles

Abstract

A stator core for an electronically commutated DC motor with an internal rotor having a plurality of radially inwardly directed pole cores which at their periphery are integral with back iron segments and the back iron segments are integral with adjacent back iron segments via webs, wherein the back iron segments alternate with the webs and jointly form a seamless closed one-piece ring. A method of ensuring that in the case of a stator core of this class, upon a reduction of the stator diameter and reduction of the pole distances after winding, a clearly defined end position of the adjoining regions can be assumed, and that for this process, only minimal forces are necessary, in which damage to the stator core is not to be expected, and that at the end of the process only a very small and uniform air gap remains at a lowest possible spring-back.

Claims

1. A stator core for an electronically commutated DC motor with an internal rotor, the stator core comprising:

a plurality of back iron segments;

a plurality of webs;

a plurality of radially inwardly directed pole cores which at their periphery are integral with the back iron segments and the back iron segments are integral with adjacent back iron segments via the webs, wherein the back iron segments alternate with the webs and jointly form a seamless closed one-piece ring, wherein the webs are arranged essentially outside of the outer circle defined by the back iron segments.

2. The stator core according to claim 1, wherein the webs have two outer predetermined bending lines and one intermediate predetermined bending line between the two outer bending lines, wherein the three bending lines are substantially thinner than in areas between the predetermined bending lines.

3. The stator core according to claim 2, wherein the two outer predetermined bending lines are arranged at transitions between the back iron segments and the webs.

4. The stator core according to claim 2, wherein the intermediate predetermined bending line is arranged between two triangular areas of each of the webs.

5. The stator core according to claim 4, wherein the distance between the intermediate predetermined bending line and the two outer predetermined bending lines is the same and is slightly larger than the thickness of the back iron segment in the radial direction.

6. The stator core according to claim 1, wherein the pole cores each have pole pieces, the spacing of which from the adjacent pole pieces is greater than the smallest distance between adjacent back iron segments.

7. A stator core with a longitudinal axis for an electronically commutated DC motor with an internal rotor, the stator core comprising:

a plurality of back iron segments;

a plurality of webs; and

a plurality of radially inwardly directed pole cores which at their periphery are integral with the back iron segments and the back iron segments are internal with adjacent back iron segments via the webs, wherein the back iron segments alternate with the webs and jointly form a seamless closed one-piece ring, wherein the webs are initially arranged essentially outside of the outer circle defined by the back iron segments and wherein the webs have two outer predetermined bending lines parallel to the longitudinal axis and one intermediate predetermined bending line parallel to the longitudinal axis and between the two outer bending lines, wherein the three bending lines are substantially thinner than in areas between the predetermined bending lines.

8. The stator core according to claim 7, wherein the two outer predetermined bending lines are arranged at transitions between the back iron segments and the webs.

9. The stator core according to claim 7, wherein the intermediate predetermined bending line is arranged between two triangular areas of each of the webs.

10. The stator core according to claim 9, wherein the distance between the intermediate predetermined bending line and the two outer predetermined bending lines is the same and is slightly larger than the thickness of the back iron segment in the radial direction.

11. The stator core according to claim 7, wherein the pole cores each have pole pieces, the spacing of which from the adjacent pole pieces is greater than the smallest distance between adjacent back iron segments.

12. A method for manufacturing a stator having a stator core for an electronically commutated DC motor with an internal rotor, the stator core having a plurality of radially inwardly directed pole cores which at their periphery are integral with back iron segments and the back iron segments are integral with adjacent back iron segments via webs, wherein the back iron segments alternate with the webs and jointly form a seamless closed one-piece ring, the method comprising the steps of:

a) winding each of the of the pole cores with a winding wire; and

b) bending each of the webs inward by direct application of force to each of the webs.

13. A method for manufacturing a stator having a stator core for an electronically commutated DC motor with an internal rotor, ), the method comprising the steps of:

providing a stator core having a plurality of radially inwardly directed pole cores which at their periphery are integral with back iron segments;

integrating the back iron segments with adjacent back iron segments via webs;

alternating the back iron segments with the webs and jointly form a seamless closed one-piece ring;

winding each of the of the pole cores with a winding wire; and

bending each of the webs inward by direct application of force to each of the webs.