MAIN ELEMENT FOR AN ELECTRICAL MACHINE

Abstract

A main element, in particular a stator, for an electrical machine, in particular for a universal motor, includes a flux return ring with at least two poles that are situated radially on the flux return ring, and each of which accommodates at least one coil, the poles can be connected with the flux return ring.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an embodiment of the inventive main element in the assembled state, in a schematic depiction.

FIG. 2 shows the main element in FIG. 1, in an exploded view, in accordance with the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The embodiment of the inventive main element depicted schematically in FIG. 1 is a stator 1 of a two-pole universal motor with an inner-rotor design. Flux return ring 10 of stator 1 is composed—in a manner known per se—of a bundle of lamina that are positioned next to each other axially, end to end (not shown). Stator 10 includes two diametrically opposed poles 20. Poles 20 are positioned over pole shoes 24 on flux return ring 10 and point radially inwardly. Poles 20 with pole shoes 24, which transition into pole horns 26 in the circumferential direction, are designed as one-piece components. A coil 22 is mounted on each one, for field excitation.

According to the present invention, poles 20 are connectable with flux return ring 10. In the embodiment shown, poles 20 are detachably connected with flux return ring 10 using a screw connection. To this end, in the exemplary embodiment shown, two boreholes 12 for each pole 20 are provided in flux return ring 10. Accordingly, poles 20 include two projections 28 with an inner thread (not shown) on surface 25 of pole shoe 24 facing flux return ring 10.

Projections 28 engage from the inside in boreholes 12 in flux return ring 10. The expression “from the inside” means that projections 28 engage in boreholes 12 from the inside of flux return ring 10. A screw 14 is guided, from the outside, through each of the boreholes 12 and engages with the inner thread of projections 28. The expression “from the outside” means that screws 14 are guided through boreholes 12 from the outside of flux return ring 10. In addition, a shim 16 with two boreholes 17 is provided for each pole 20 that bears against the outside of flux return ring 10.

Boreholes 17 in shim 16 align with boreholes 12 of flux return ring 10. Shims 16 enable force to be distributed across a wide area when poles 10 are screwed down, since the pressing force acts not only between the surface of the screw head bearing against flux return ring 10 and the lamina bundle of flux return ring 10, it is also distributed over the entire surface area of shims 16.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the type described above.

While the invention has been illustrated and described as embodied in a main element for an electrical machine, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention.

Claims

1. A main element for an electrical machine, comprising a flux return ring with at least two poles that are situated radially on said flux return ring; at least one coil accommodated in each of said two poles, wherein said poles are connected with said flux return ring.

2. A main element as defined in claim 1, wherein the main element is configured as a stator.

3. A main element as defined in claim 1, wherein the main element is configured as a stator for the electrical machine which is a universal motor.

4. A main element as defined in claim 1, wherein said poles are connected with said flux return ring in a form-fit manner.

5. A main element as defined in claim 1, wherein said poles are connected with said flux return ring in a non-positive manner.

6. A main element as defined in claim 1, wherein said poles are connected with said flux return ring in a bonded manner.

7. A main element as defined in claim 1, wherein said poles are detachably connected with said flux return ring.

8. A main element as defined in claim 1, wherein said poles are connected with said flux return ring via a screw connection.

9. A main element as defined in claim 1, wherein said flux return ring is configured as a one-piece component.

10. A main element as defined in claim 1, wherein said flux return ring is configured as lamina bundle.

11. A main element as defined in claim 1, wherein said poles are configured as one-piece components.

12. A main element as defined in claim 1, wherein said poles are composed of iron.

13. A main element as defined in claim 1, wherein said poles are composed of sintered metal.

14. A universal motor, comprising a main element including a flux return ring with at least two poles that are situated radially on said flux return ring, and at least one coil accommodated in each of said two poles, wherein said poles are connected with said flux return ring.