Metal working – Method of mechanical manufacture – Electrical device making
Reexamination Certificate
1999-06-02
2001-05-15
Hall, Carl E. (Department: 3729)
Metal working
Method of mechanical manufacture
Electrical device making
C029S732000, C029S736000
Reexamination Certificate
active
06230388
ABSTRACT:
FIELD OF THE INVENTION
The invention relates to a method for producing a stator for electric machines, wherein a plurality of coils is prewound and drawn into a stator lamination package, and wherein prior to draw-in the wire ends of the coils are temporarily connected in a defined pre-aligned position with a holding element, which is separate from the stator lamination package, and after draw-in they are fixed in place in a predetermined position in respect to the stator lamination package. The invention also relates to a draw-in tool element for executing the method.
BACKGROUND OF THE INVENTION
It is a common practice to grasp the wire ends, which are already respectively present at the end of the winding process of the coils or groups of coils after having been cut off from the wire supply, only after all coils have been drawn into the stator lamination package and immediately prior to fixing them on defined terminals or auxiliary terminals. In connection with stators with a low number of poles, grasping and fixing the wire ends in place does not present any difficulties and can be performed to a large extent without errors, since it can be easily determined with which coil a particular wire end is associated. However, in connection with stators with many poles, for example with 72 poles, there are 144 wire ends, which often cross and which can only be arranged by laborious manual work by interconnection or on terminals or auxiliary terminals.
It is known from U.S. Pat. No. 5,542,456 to initially fix the wire ends in place on holding devices which are connected with an element of the draw-in tools being used as coil receivers. In the course of the drawing-in process, a mechanical transfer of the wire ends to further holding elements, which are connected with the stator lamination package, takes place. The wire ends are finally brought into their predetermined position, which is fixed in relation to the stator, only after a further mechanical transfer process. The transfer of the wire ends during the drawing-in process represents an additional risk, in particular with thin wires and automatic production processes.
DE 31 14 407 C2 describes a drawing-in process, not performed up to now, wherein the coils are drawn down into a stator lamination package from above. On its upper end face, the latter is connected with a ring, on which the wire ends are fastened already in connection with the winding process of the coils. Such a ring has the disadvantage that it prevents the armoring of the end windings. The unusual drawing-in method furthermore has to rely on the fact that the coils created on a template must initially be received by a tool element consisting of rods arranged in a ring shape, and from there transferred between the lamellas of the draw-in tool. However, in connection with automatic production methods it is endeavored to strip the coil windings from the template directly into the gaps between the lamellas of the draw-in tool in order to prevent errors and damage to the wires in the course of transferring the wire windings.
OBJECT AND SUMMARY OF THE INVENTION
The invention is based on the object of providing a method and a draw-in tool element, which is suitable for executing the method, by means of which it is possible to interconnect the wire ends of the coils and to fasten them at the terminals or auxiliary terminals provided more dependably and faster than up to now, regardless of whether they are stripped off the winding template into a transfer tool or a draw-in tool.
The above object is attained in that while drawing-in the wire ends of the coils, they remain connected with the holding element and after the draw-in are mechanically removed from the holding element and transferred into the predetermined position, which is fixed in relation to the stator lamination package.
The invention offers the advantage that in the continuously progressing production process it is comparatively simple to temporarily connect the wire ends in a defined position with a separate holding element respectively directly in the course of winding a coil or group of coils, and to maintain them connected during the draw-in of the coils into the stator lamination package. This proposal is based on the consideration that following the termination of each winding process, the wire ends still are in a defined position. Therefore they should not be first released and, following the drawing-in process, laboriously caught again, but instead they should be maintained in order throughout the drawing-in process, as well as during a possible forming operation for shaping the end windings. A prerequisite for this is only the mentioned additional holding element, with which the wire ends remain connected during the drawing-in process and possibly during the forming operation. For example, a simple disk or plate with holders, or respectively clamping places, for the individual wire ends at the circumference is sufficient for this, which is connected with the draw-in tool element, or which can be placed without the stator lamination package onto the draw-in tool element, which is provided with parallel lamellas, or respectively rods arranged in a ring shape, or on a transfer tool, which receives the coils after winding and holds them until they are drawn into the stator lamination package.
Following the draw-in of the coils, it is recommended to turn the stator lamination package so that now the support plate constituting the disk-shaped holding element is located above the stator lamination package and can be lifted off, and to mechanically grasp the wire ends prior to or following the lifting process and to transfer them into the position determined by the terminals or auxiliary terminals, or to interconnect them. However, the novel method can also be performed without turning the stator lamination package.
In the preferred practical embodiment of the method, the coils are checked simultaneously or separately for current passage while the wire ends are still in the prealigned position, for example prior to or during draw-in and/or following this process. In this way the invention offers the possibility of already detecting wire failures or insulation errors in the coils at an early stage of production and of saving expenses in this way.
A draw-in tool element proposed for executing the method in accordance with the invention in the customary manner receives coil windings, which are wound on a template, between parallel lamellas arranged in a ring shape and can be connected with a draw-in device, through which the coils can be stripped off the lamellas into the grooves of a stator lamination package, but as a characteristic feature has a support plate for the coils, on whose exterior circumference holding devices for the releasable connection with the wire ends of the coils are attached, which can be provided with potential electrical contacts.
Exemplary embodiments of the invention will be explained in greater detail in what follows.
REFERENCES:
patent: 4723354 (1988-02-01), Moser
patent: 5542456 (1996-08-01), Nishimura et al.
patent: 31 14 407 (1989-03-01), None
Hall Carl E.
Larson & Taylor PLC
Statomat GmbH
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