GB2028186A

GB2028186A - Stator coil shaping device

Info

Publication number: GB2028186A
Application number: GB7928611A
Authority: GB
Original assignee: VESER F
Current assignee: VESER F
Priority date: 1978-08-16
Filing date: 1979-08-16
Publication date: 1980-03-05
Also published as: FR2433848A1; DE7824310U1; GB2028186B; FR2433848B3

Abstract

A device is provided for shaping the ends of stator coils in the region where the coil ends beyond the stator slots. The device comprises a shaping ram (6) and several draw hooks (5) preferably two, with retaining rods (4), which can be hooked to the coil overhang flanks. The hooks and ram are formed as a shaping tool. A thrust device is provided having a push rod (9) which can pass the shaping ram against the coil overhang (16) while the draw hooks pull in the opposite direction. These components form a single-handed appliance which is provided with a pistol grip (1a) and an operating lever (11), with which it is possible to exert a thrust force with high mechanical advantage upon the shaping tool to effect a pressing action to flatten the ends of the coils. <IMAGE>

Description

SPECIFICATION Stator coil shaping device This invention relates to a shaping device for the stator coil overhangs of electric machines, where the coil overhang is flattened off by pressing inwards.

A conventional method still used for winding stators consists in that the wire loops of a coil are inserted successively by hand into the stator grooves (insertion one-by-one), in which case the coil overhang must also be shaped by hand by correct bending of the individual wires. This time-consuming work is caused by the fact that the finished coil overhang possesses a very compact rigid structure which renders possible manual shaping at most in the case of very small stators. In all other sizes one is compelled to use the complicated manner of operation as mentioned. The aids used here, for example presser bars, require special practice and experience. Moreover there is danger here of damage to the insulating varnish.Special difficulties arise in the case of multi-hole or multi-layer coils, since in this case several coil overhangs must be arranged by re-shaping into the restricted space in the stator.

In order to replace the time-consuming task of one-by-one insertion, winding methods have been developed in which the coil is pushed or drawn as a whole into the stator groove, while at the same time an advantageous increase of the maximum coil mass is also achieved. This however has the consequence that the finished, very compact coil overhangs can be shaped now only with mechanical means. For this purpose extensive and costly mechanical devices have been proposed the purchase and use of which is completely uneconomical for small or medium concerns with short workpiece runs, and especially also for repair concerns. On the other hand the form of the coil overhang is very important especially in the case of multi-pole coils or multi-layer coils, for expedient spatial accommodation of the coil overhangs in the inherently limited space on the stator circumference.

Therefore the problem of the invention consists in replacing both the time-consuming and obsolete manual shaping, which is disadvantageous as regards winding technique, and the expensive special shaping machines, by a shaping device in which the purchase expense is low and the operation is simple, while nevertheless the quality of the coil should fully conform with the demands of modern winding technique.

The invention achieves this by a shaping device in which a shaping ram and several draw hooks, preferably two, with retaining rods, for hook attachment to the coil overhang flanks are provided as shaping tool, while a thrust device with a thrust rod is provided which can press the shaping ram against the coil overhang while the draw hooks pull in the opposite direction. These means are components of a single-handed appliance which is provided with a pistol grip and an operating lever with which it is possible to exert a thrust force with high mechanical advantage upon the shaping tool.

Such a shaping device renders it possible even for an untrained labourer to shape the coil overhangs optimally with low expenditure of force. The purchase costs are so low that a shaping appliance can be made available for every working station, whereby the progress of work is promoted. In order to guarantee exactly the intended coil overhang form, in accorance with the invention for the actuation of the push rod a stepping device is provided so that the shaping operation proceeds stepby-step and thus can be monitored constantly.

Moreover in accordance with the invention the thrust side of the shaping ram is provided with a hollow profile which corresponds approximately to the half cross-section of the coil overhang, the bottom of the profile being domed in convex form in the thrust direction.

Thus in the shaping the ram encloses the coil length concerned, whereby shaping is favoured and damage to the varnish insulation of the wires is avoided. The convex profile bottom produces a slight and expedient inward bulging of the coil overhang.

Further details of the invention are described with reference to the drawing, in which an example of embodiment is illustrated and wherein: Figure 1 shows the lateral elevation of the device and Figure 2 shows the plan view of Fig. 1, with stator cut open.

A pistol-type hand grip 1 a is formed on the housing 1 of the device and a flange 2 provided with bores 3, 3a is secured to the housing 1. In two of these bores 3 there are secured the retaining rods 4 which possess the draw hooks 5 at their ends. The shaping ram 6 is longitudinally displaceably guided by lateral guide grooves 6a on the retaining rods 4. The shaping ram 6 is provided with a hollow profile 7 having a convexly domed profile bottom 8.

In the housing 1 a longitudinally movable push rod 9 is guided which rests with its thrust plate 10 against the shaping ram 6 and can be moved in the direction of the arrow P in the housing 1 by the operating lever 11.

The operating lever 11, which is pivotable about the spindle 12, here acts through a known stepping device with high mechanical advantage upon the toothing 1 3 of the push rod, the thrust device being formed in known manner so that the push rod 9 disengages and can be withdrawn after rotation through 180 (shown in dot-and-dash lines).

In order to bring the coil overhangs 16, originally protruding from the stator 1 5 approximately as indicated by the dot-and-dash line W, into the expedient form as shown, that is to say especially to flatten them off, the shaping ram 6 is applied so that its hollow profile embraces the coil overhang on three sides. At the same time the draw hooks 5 are applied to the inner angles of the coil overhang. Then by operation of the operating lever 11 the push rod 9 can be moved in the direction of the arrow P against the shaping ram 6, whereby the latter exerts an adequate pressure force step-by-step upon the apex curve W of the coil overhang 1 6 and flattens the latter off or slightly presses it in.In this operation a reaction force in the opposite direction takes place upon the draw hooks 5 having the effect that the coil is not forced back into the stator, and furthermore a positioning of the side strands 1 7 is guaranteed which is expedient for the accommodation of the further coil overhangs.

In order to reinforce this effect the guide faces for the shaping ram 6 on the retaining rods can be formed so that they converge in the thrust direction, as indicated in dot-anddash lines. Thus in collaboration with the correspondingly formed guide grooves 6a, in the advancing movement of the shaping ram the elastic retaining pieces 4 and thus the draw hooks 5 are forced outwards and thus contribute to the desired flattening of the coil overhang.

After conclusion of the shaping operation the push rod 9 is turned through 180 and can then be withdrawn by means of the angle grip 1 8. Thus the shaping ram 6 and the draw hooks 5 are also relieved of load and can be brought into an initial position.

In order to make the device usable for different sizes of coils, the flange 2 is provided with several pairs of bores 3, 3a in which it is possible to fit retaining rods 4 with smaller or larger transverse intervals, so that correspondingly shaping rams 6 of different sizes can also be used. Moreover here the length of the draw hooks 5 can be adapted to the position and thickness of the coil overhangs, which is expedient especially in the case of multi-layer coils. With this type of coil or in the case of multi-hole coil groups, the value of the described device comes into full effect, because it is possible to shape the coil overhangs, lying side-by-side and one above the other, so that they can be accommodated in orderly manner in the available restricted space in the end of the stator.

Claims

1. Shaping device for the stator coil overhangs of electric machines, where the coil overhang is flattened by pressing in, wherein a shaping ram and several draw hooks preferably two, with retaining rods, which can be hooked to the coil overhang flanks, are provided as shaping tool and in that a thrust device is provided having a push rod which can press the shaping ram against the coil overhang while the draw hooks pull in the opposite direction, and further in that these means are components of a singlehanded appliance which is provided with a pistol grip and an operating lever, with which it is possible to exert a thrust force with high mechanical advantage upon the shaping tool.

2. Shaping device as claimed in Claim 1, wherein a stepping device is provided for the actuation of the push rod.

3. Shaping device as claimed in the preceding Claims, wherein the thrust side of the shaping ram is provided with a hollow profile which corresponds approximately to half the cross-section of the coil overhang the profile bottom being domed convexly in the thrust direction.

4. Shaping device as claimed in the preceding Claims, wherein the shaping ram arranged between the draw hooks is provided with lateral grooves or bores for guidance on retaining rods.

5. Shaping device as claimed in the preceding Claims, wherein the guide faces on the elastic retaining rods converge in the thrust direction so that the draw hooks are forced against the inner angles of the coil overhang by the advancing movement of the shaping ram.

6. Shaping device as claimed in the preceding Claims, wherein the shaping ram and its retaining rods are made exchangeable for adaptation to the size in each case of the coil overhangs to be shaped.

7. Shaping device as claimed in Claim 5, wherein a flange is fitted on the housing and provided with several bores having different intervals from one another in the transverse direction, for the securing of the retaining rods.

8. Shaping device as claimed in the preceding Claims, wherein that the shaping ram consists of a material capable of slipping when dry, for example of polyamide.

9. Shaping device for the stator coil overhangs of electric machines, substantially as described with reference to the accompanying drawings.