Stator winding of the electric motor of an elevator machine

Abstract

Stator winding in the stator of the electric motor of an elevator machine, said stator comprising a stator frame (1) provided with stator teeth (11) and slots (12) between them, the stator winding (2) being fitted in said slots (12). The stator comprises a winding frame (3) having a bottom (31) facing against the slot and sides (32), in which winding frame the winding can be fitted, and it has strip-like or stick-like elements (4) of ferromagnetic material fitted at the mouths of the slots (12) to control the magnetic flux.

Description

The present invention relates to a stator winding in the stator of the electric motor of an elevator machine, said stator having a stator frame provided with stator teeth and slots between them, the stator winding being fitted in said slots.

The stator of electric motors used in elevator machines consists of a stator frame having stator teeth and stator slots between them, and a stator winding arranged in the stator frame around the teeth. The stator frame may be laminated from thin plates forming a stator pack. The conductors of the stator winding are placed directly in the stator slots e.g. as conductor bundles. The conductors are held in the slots by means of slot wedges fitted at the upper edge of the slot. The slot wedges may form a dovetail joint with the upper edge of the slot. A drawback with prior-art stators is a relatively slow and complicated winding process.

In addition, it is necessary to prevent conductor movements in the slots caused by mechanical forces. For this purpose, it may be necessary to apply a sealant between the wedge and the conductors, or else each slot wedge is provided with an adapter piece having friction surfaces on its sides and two side pieces with corresponding friction surfaces on their sides, as described e.g. in patent application FI-A-884154. These solutions are also relatively complicated.

The object of the present invention is to achieve a new type of stator winding structure that will allow a faster winding process. The mounting structure of the invention is implemented using a plastic winding frame of e.g. trough-like shape, around which the stator winding is fitted. The winding frame comprises a slot stick, preferably of ferromagnetic material, adapted to the shape of the mouth of the slot. The slot stick can be fastened securely by casting it fast on the winding frame. The slot stick can be shaped freely. The features characteristic of the solution of the invention are presented in detail in the claims below.

Since the slot stick is firmly fastened to the coil former, it is not possible for the slot stick to be released. The invention makes it possible to achieve a simple, fast and economical winding process, especially because the windings can be prepared as complete packs before being mounted in the stator slots.

In the following, the invention will be described in detail by the aid of and example with reference to the attached drawings, wherein

FIG. 1 presents a stator according to the invention, comprising a plastic winding frame and a slot stick,

FIG. 2 presents another stator according to the invention with a plastic winding frame for an electric motor, and

FIG. 3 presents a magnified view of detail A in FIG. 2.

FIG. 1 represents the stator of a cage induction motor used as an elevator hoisting motor. The stator consists of a stator frame 1 having stator teeth 11 and stator slots 12 between them. The motor has a stator winding (field pole coil) 2 placed around the stator tooth 11, wound around a trough-like plastic winding frame 3, the bottom 31 of the winding frame 3 being placed against the side face of the tooth 11. The winding frame 3 comprises a slot stick 4 made of ferromagnetic material, extending over the mouth of the slot and adapted to its shape, for controlling the magnetic flux. The slot stick has been cast inside the winding frame 32 on one side of it, so the slot stick 5 is firmly fastened in the winding frame and can not be detached. Before being mounted on the stator slots 12, the windings 2 are fitted in the winding frames 3 to form complete winding packs and then mounted on the stator frame by pushing them into the slots 12.

FIGS. 2 and 3 illustrate a second embodiment of the invention, in which the bottom 31 of the winding frame 3 is provided with small elastic locking tongues 33 projecting from the bottom. When the stator winding is being pushed into the slot 12, the locking tongues will snap in into holes 13 provided in the slot of the stator frame. The locking elements 33 thus prevent the field pole coil from moving out from the stator frame.

It is obvious to the person skilled in the art that different embodiments of the invention are not limited to the example described above, but that they may be varied within the scope of the claims presented below.

Claims

1. Stator winding in the stator of the electric motor of an elevator machine, said stator comprising a stator frame provided with stator teeth and slots between them, the stator winding being fitted in said slots, wherein the stator comprises a winding frame having a bottom placed against the slot and sides, in which winding frame the winding can be fitted, and that it comprises strip-like or stick-like elements of ferromagnetic material fitted at the mouths of the slots for controlling the magnetic flux.

2. Stator winding according to claim 1, wherein said elements are fitted inside the winding frame.

3. Stator winding according to claim 1, wherein said elements are shaped to follow the form of the mouth of the slot.

4. Stator winding according to claim 1, wherein the winding frame comprises flexible locking elements projecting from the bottom, which locking elements can be fitted into holes provided in the slots and which, when the winding frame is being pushed into the slot, are inserted into the holes and lock the winding frame and the stator winding to the stator frame.

5. Stator winding according to claim 1, wherein the winding frame is substantially trough-like.

6. Stator winding according to claim 1, wherein the winding frame is made of a plastic-like material.

7. Stator winding according to in claim 1, wherein the locking elements are of the same material as the winding frame.