JPH03207231A - Stator for rotating electric machine - Google Patents

Abstract

PURPOSE:To correct loosening of wedge by building a pressure piece into a part of liner when securing an armature coil, to be inserted into the slot of core, by means of the wedge and the liner disposed in the vicinity of the opening of the slot. CONSTITUTION:Armature coils 1a, 1b are inserted into the slot 3 of a core 2 and then a liner 5 and a wedge 4 having trapezoidal cross section are inserted into the proximity of the opening of the slot 3 in order to block movement of the coils 1a, 1b. The liner 5 is provided with a groove 7 into which a pressure piece 8 is placed. The pressure piece 8 comprises a tubular film 9 encapsulating liquid material 10. When the affinity or quality of each part in the slot the contacting position degrades due to rotation to cause loosening of the wedge 4, the pressure piece 8 inflates through temperature rise to correct the wedging force. Consequently, period of wedge regulating work requiring withdrawal of rotor is extended resulting in reduction of maintenance cost.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to means for fixing an armature coil in a rotating electric machine.

[Conventional technology]

Generally, an armature coil of a rotating electrical machine is inserted into a slot in an iron core, and is held in the slot by a wedge provided near the opening of the slot. The wedge is firmly driven to press the coil sufficiently against the bottom of the slot so that the coil is moved by electromagnetic force and does not cause deterioration of electrical properties such as abrasion of the insulating layer. However, when the device is operated, the coil binding force of the wedge decreases due to the ``familiarity'' of various parts due to electromagnetic force and vibration, and ``withering'' due to heat of the insulating layer and wedge. If the restraining force falls below the standard value, the wedge is removed once, the thin plate is added and the wedge is re-inserted, and the restraining force is restored.

To do this, it is necessary to stop one piece of equipment and take out the rotor, which requires a lot of money and a lot of work days.

In order to eliminate such inconveniences, methods have been proposed for correcting the gap generated within the slot and for restoring the binding force without first removing the wedge. Examples include JP-A No. 59-213250 and Utility Model Application No. 61-8.
There is a publication No. 1753.

[Problem to be solved by the invention]

FIG. 5 shows a slot cross section of a stator according to the prior art.

Insert the bottom coil la and the upper coil l into slot 3 of iron core 2.
b. Two armature coils are inserted, and a wedge 4 is provided near the slot opening. Inter-coil liner 6
In addition, a wedge lower liner 5 is inserted so as to eliminate a gap in the slot, and the pressure from the wedge acts toward the bottom of the slot as a coil restraining force.

Generally, wedges and liners are made of synthetic resin laminates, 1 and when exposed to a high temperature atmosphere for a long time, a slight dimensional reduction called "withering" occurs, which reduces the pressure of the wedge.

In addition, as shown in Figure 6, in a rotating machine with a cooling ventilation passage, the temperature of the B zone, into which the air flows after cooling the A zone, is high, so the wedges installed in the B zone will wither to a large extent. has been confirmed.

The above-mentioned Japanese Patent Application Laid-Open No. 59-213250 points out that the iron core has temperature irregularities in the stacking direction, and the wedge installed in the high temperature part has a large "withering", which reduces the reaction force of the elastic body. There was a problem in that the restraint force was lower than in other areas where the restraint force should be equalized by a larger reaction force.

Furthermore, although Patent Publication No. 1981-81753 has the advantage of being able to restore the binding force of the coil without removing the wedge, it does not correct the binding force of the wedge during operation, similar to the prior art described above. The problem was that it was not possible.

SUMMARY OF THE INVENTION An object of the present invention is to provide a stator for a rotating electrical machine that corrects and restores unevenness in the wedge coil restraint force caused by temperature differences in the iron core during operation.

[Means to solve the problem]

In order to achieve the above object, a pressurizer made of a material with a large thermal expansion is installed between the wedge and the coil, and a pressure corresponding to the temperature is applied to the wedge and the coil.

[Effect]

Since the expansion layer of the pressurizer differs depending on the temperature of the location where it is installed, the expansion is large in the high-temperature parts of the iron core and less in the low-temperature parts. On the other hand, wedges tend to wither more and the coil binding force decreases as the ambient temperature increases, but by using a pressurizer together.

The expansion force depending on the temperature compensates for the decrease in binding force and restores the wedge, so the wedge never loosens.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG. The armature coils La, lb are inserted into slots 3 of the iron core 2, and a wedge 4 is provided near the slot opening. A liner 5 is inserted between the wedge 4 and the coil 1. As shown in FIG. 2, a groove 7 is machined in the liner, and a presser element 8 is installed in the groove. As shown in FIG.
〇 is enclosed.

When such a device is operated, the contact portions of the various parts in the slot become loose, and the internal temperature of the device increases, causing the parts to wither, and the coil binding force of the wedge is relatively reduced. However, according to this embodiment, the pressurizer expands according to the rise in temperature inside the machine, and the pressurizer expands between the live and the wedge.
Since a force is generated to push and spread the coil, it is possible to compensate for the decrease in the coil restraint force described above and restore it to the design value.

Further, even if there is a difference in temperature rise within the same machine, a large expansion force is generated in the high temperature section where drying is likely to occur, so it is possible to obtain a uniform coil binding force overall.

As for the material of the presser, in addition to liquid materials such as silicone grease, it is also possible to use thermally elongated solid nonmagnetic metal 111 as shown in FIG.

Furthermore, although the description has been made by inserting the pressurizer between the wedge and the liner, the same effect can be obtained by placing the pressurizer between the liner and the coil, between the coils, or between the coil and the bottom of the slot.

〔Effect of the invention〕

According to the present invention, wedge loosening caused by fitting or withering of components within the slot can be corrected by the expansion force of the pressurizer depending on the temperature of the iron core.

For this reason, the interval for wedge stiffness adjustment work that involves removing the rotor can be set longer than in the past, which has the effect of reducing the period and costs for preventive maintenance.

[Brief explanation of drawings]

FIG. 1 is a sectional view of the slot portion of one embodiment of the present invention, and FIG.
The figure is a perspective view of the pressurizer of the present invention, and Figure 3 is from ■ to ■ in Figure 2.
A line sectional view, FIG. 4 is a perspective view showing another embodiment of the present invention,
FIG. 5 is a sectional view of a slot according to the prior art, and FIG. 6 is a sectional view of a rotating electric machine equipped with a ventilation path.

Claims (1)

[Claims] 1. Includes an iron core having a slot, an armature coil inserted into the slot, a wedge provided near the opening of the slot, and a liner filling the inner gap of the slot. A stator for a rotating electrical machine, characterized in that a pressurizer is incorporated into a part of the liner.