JPH1189151A - Rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a shaft-bending moment from being generated and to reduce the rotary vibration of a rotor by providing a film with a low friction coefficient at each of a slide surface in the coil slot of the rotor. SOLUTION: A number of coil slots 7 that are recessed grooves being directed from an outer-periphery surface being extended in axial direction toward a center direction are formed at a rotor. A coil 6 and a wedge 3 for pressing the coil 6 are accommodated in the coil slot 7 via a creepage block 3 for insulation, and a film 9 with a low friction coefficient (0.01 or less) is formed on a surface that opposes the coil 6 of the creepage block 3 and a surface that opposes the creepage block 3 of the coil 6 and/or a surface that opposes the wedge 3 of the coil 6 and the surface that opposes the coil 6 of the wedge 3, thus facilitating the relative move of the rotor in the direction of a rotary axis and reducing the rotary vibration of the rotor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotating electric machine, and more particularly to a rotating electric machine in which vibration of a rotor is reduced.

[0002]

2. Description of the Related Art In a conventional rotating electric machine, there is a problem that the vibration of the rotor may exceed an allowable value due to deterioration of the vibration characteristics of the rotor and hinder the operation. As a technique for suppressing the vibration of the rotor, for example, Japanese Patent Application Laid-Open No. 54-131
No. 704 discloses a thermal balance method for a rotor in which the wedge of the rotor is shifted in the axial direction to adjust the flow rate of the cooling gas.

[0003]

However, it has been difficult to reduce the vibration of the rotor to an allowable range even if the above-mentioned conventional thermal balance method is employed. The inventor of the present application has studied the vibration mechanism of the rotor and has completed the present invention.

[0004] That is, the vibration of the rotor is caused by reasons such as short-circuiting between layers due to damage to the coil, interlayer insulation, spacers, etc. accommodated in the rotor, changes and variations in the coefficient of friction, and dimensional changes in each member. The non-uniformity of the axial stress distribution appears during the operation of the rotating electric machine, and as a result, the rotor is caused by the shaft bending moment. It was found that remarkable shaft vibration occurred.

An object of the present invention is to provide a rotating electric machine in which the above-described shaft bending moment is prevented from occurring, thereby reducing the rotational vibration of the rotor.

[0006]

In order to solve the above problems, a rotating electric machine according to the present invention is a rotating machine including a rotor and a stator rotatably supporting the rotor, the rotating machine comprising: The coil slot, which is a concave groove extending from the outer peripheral surface extending in the axial direction toward the center, is formed in the coil slot.The coil slot has a coil through an insulating crease block and a coil for holding the coil. A wedge is housed therein, and each of a surface of the coil block facing the coil, a surface of the coil facing the page and / or a surface of the coil facing the wedge, and a surface of the wedge facing the coil. Are characterized in that a film having a low coefficient of friction is formed on each of them.

As described above, by providing a film having a low friction coefficient on each of the sliding contact surfaces (the two low friction films provided on each of the sliding contact surfaces are referred to as a slider for convenience).
The relative movement of the rotor in the direction of the rotation axis is easily possible,
The generation of the shaft bending moment of the rotor is reduced, and the vibration of the rotor can be reduced.

[0008]

Embodiments of the present invention will be described below with reference to embodiments shown in the drawings. FIG. 1 is a diagram showing a cut model of a rotating electric machine according to one embodiment of the present invention.
As described above, the rotary machine is roughly composed of the rotor 12 and the stator 13 that rotatably supports the rotor 12. The rotor 12 has a large number of concave grooves (coil slots) formed in the rotor 12 from the outer peripheral surface extending in the axial direction toward the center of the rotor 12.

FIG. 2 shows the relationship between the axial distance and the axial stress when the friction coefficient of the sliding contact surface (the detailed position is described later) in the coil slot is changed by various analyzes. is there. Here, the coil center part at the axial distance is the center part in the longitudinal direction of the coil (axial direction of the rotor), and the coil end parts are both ends in the longitudinal direction of the coil (axial direction of the rotor). Part.

As shown in FIG. 2, the correlation between the shaft bending moment generated on the rotating shaft of the rotating electric machine due to the friction coefficient μ between the click page block and the coil is, for example, μ = 0.01 or less, or μ = 0.3 or more. Although the ratio of the change of the axial bending moment to the change was small, it was considerably large around μ = 0.1, and it was found that the non-uniformity of the bending moment caused by the variation of the friction coefficient was considerably increased. The critical friction coefficient (coefficient where the rate of change of the axial bending moment changes rapidly) can be obtained by using elastic mechanical calculation or material mechanical calculation.

As can be seen from FIG. 2, when the friction coefficient of the sliding contact portion is set to μ = 0.01 or less, the axial stress can be stably reduced even if the friction coefficient slightly changes. However, there is no material suitable for a rotating electric machine having a friction coefficient of μ = 0.01 or less. PTFE (polytetrafluoroethylene) is a material suitable for a rotating electric machine and having a low friction coefficient. The friction coefficient of this material is a value larger than μ = 0.01. In order to realize a friction coefficient of μ = 0.01 or less, it is conceivable that two PTFE layers are stacked to lower the friction coefficient.
Is soft, so it is a common theory that the friction coefficient increases when two soft materials are stacked, and there is no example in which two PTFE members, which are members exhibiting a low friction coefficient, are stacked.

However, when two members of PTFE (polytetrafluoroethylene), which is a member exhibiting a low friction coefficient, were subjected to an experiment, the friction coefficient was μ = 0.0
It could be less than 1.

FIG. 3 is an enlarged view around the coil slot 7 formed in the rotor 12. The coil slot 7 has a slot insulation 5 for electrical insulation from the iron core 1 which is a base material of the rotor. Each layer of the coil 6 is wound around the iron core 1 while maintaining electrical insulation via the turn insulation 8. There is a coil 6 that is being used. On the surface side of the rotor 12 of the coil 6, a crease block 3 for insulation is arranged, and a wedge 2 exists to prevent these from jumping out due to centrifugal force.

In order to absorb the axial relative movement in the rotor that occurs when the rotating electric machine is operated, each of a surface of the coil block block facing the coil, a surface of the coil facing the clip page block, and A film having a low coefficient of friction is formed on each of the surface of the coil facing the wedge and the surface of the wedge facing the coil.

As in the present embodiment, the clear page block 3
It is desirable to provide the slider 4 on both the sliding surface between the motor and the coil 6 and the sliding surface between the wedge 2 and the crease block 3, but if provided on any one of them, the effect of reducing the rotational vibration of the rotor is obtained. There is.

FIG. 4 is an enlarged view of the slider 4 disposed on the sliding surface between the clear page block 3 and the coil 6. The slider 4 has a structure in which two low-friction films 9 are in sliding contact with each other, and the surfaces of the low-friction film 9 opposite to the sliding contact surfaces are fixed to the click page block 3 and the coil 6, respectively.

As the low friction film 9, for example, PTFE
(Polytetrafluoroethylene) is suitable, but PTFE
However, any material that is stable against aging, has small variations, and exhibits a low friction coefficient may be used.

FIGS. 5 to 8 are diagrams schematically showing the relationship among the coil 6, the crease block 3, and the wedge 2 in the axial section of the rotor 12. FIG. FIG. 5 shows the stopped state of the rotor of the conventional rotary machine, FIG. 6 shows the operating state of the rotor of the conventional rotary machine, FIG. 7 shows the stopped state of the rotor of the rotary machine of the present embodiment, and FIG. The arrow (←) indicates the axial stress in the operating state of the rotor of the rotary machine, and the length of the arrow (←) indicates the magnitude of the stress.

As shown in FIGS. 5 and 6, in the rotor of the conventional rotary electric machine, an axial stress that is not generated at all when the rotor is stopped causes an increase in the temperature of the rotor due to the operation, and a contact surface in the rotor. It is caused by the variation of the contact coefficient, the difference of the coefficient of linear expansion of the material, the difference of the centrifugal force, etc., and the shaft is bent due to the bending moment generated on the shaft due to the axial stress.
Vibration occurs in the rotor.

On the other hand, the rotor of the rotary electric machine according to the present embodiment has a sliding surface between the clickable block 3 and the coil 6 and a wedge 2 and the clearpage block 3 as shown in FIGS. The slider 4 is arranged on the sliding surface. During operation, as shown in FIG. 8, the slider 4 having the lowest coefficient of friction easily causes relative movement in the axial direction to reduce the axial stress of the rotor, and the axial bending moment of the rotor and its variation. And the occurrence of shaft vibration can be prevented.

[0021]

According to the present invention, it is possible to provide a rotating electric machine in which the rotation vibration of the rotor is reduced by preventing the generation of the shaft bending moment of the rotor.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a cut model of a rotating electric machine according to one embodiment of the present invention.

FIG. 2 is a diagram showing a relationship between an axial distance and an axial stress when a friction coefficient of a sliding contact surface is changed according to one embodiment of the present invention.

FIG. 3 is an enlarged view of a rotor according to one embodiment of the present invention.

FIG. 4 is an enlarged view of a slider according to one embodiment of the present invention.

FIG. 5 shows a coil, in an axial cross section of a conventional rotor.
FIG. 4 is a diagram schematically illustrating a relationship between a click page block and a wedge. (When stopped)

FIG. 6 shows a coil in an axial cross section of a conventional rotor;
FIG. 4 is a diagram schematically illustrating a relationship between a click page block and a wedge. (During operation)

FIG. 7 is a diagram schematically illustrating a relationship between a coil, a crease block, and a wedge in an axial cross section of a rotor according to an embodiment of the present invention. (When stopped)

FIG. 8 is a diagram schematically illustrating a relationship between a coil, a crease block, and a wedge in an axial cross section of a rotor according to an embodiment of the present invention. (During operation)

[Explanation of symbols]

1: Iron core, 2: Wedge, 3: Cripage block, 4
... Slider, 5 ... Slot insulation, 6 ... Coil, 7 ... Coil slot, 8 ... Turn insulation, 9 ... Low friction film, 1
0 ... Retainer.

Claims (3)

[Claims] 1. A rotating machine comprising a rotor and a stator rotatably supporting the rotor, wherein the rotor has a concave groove extending from an outer peripheral surface extending in an axial direction toward a center. A certain number of coil slots are formed, and the coil slot houses a coil and a wedge for holding the coil via an insulating crease block, and the coil of the crease block is A low coefficient of friction is applied to each of the opposing surface, the surface of the coil opposing the cut page block, and / or the surface of the coil opposing the wedge, and the surface of the wedge opposing the coil. A rotating electric machine characterized in that a film of (1) is formed. 2. The coefficient of friction between the opposing films is:
The rotating electric machine according to claim 1, wherein the rotating electric machine is 0.01 or less. 3. The film according to claim 1, wherein the material of the film is polytetrafluoroethylene (PTFE).
The rotating electric machine as described.