JPS6162337A - Rotor wedge of rotary electrical machine - Google Patents

Abstract

PURPOSE:To prevent accumulation of fretting fatigue by periodically changing spacer positions. CONSTITUTION:A coil 3 is inserted in a slot 4 axially excavated in a rotor 1, and wedges 2 are inserted in the outer periphery of the slot 4 so that the coil 3 is not caused to run out by the centrifugal force due to rotation of the rotor. Several sets of spacers 8 of axial thicknesses t1 and t2 different from each other are inserted between the adjacent wedges of the wedges 2 at both axis ends, and both spacers 8 are periodically changed to axially shift the position of the wedge seam 6. With this construction, fatigue occurring in the wedge seam portion of a rotor core is prevented from being accumulated to the amount causing cracks.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to providing a spacer between wedges, and particularly to a rotor wedge of a rotating electrical machine suitable for changing the position of a wedge joint.

[Background of the invention]

A rotor wedge of a conventional turbine generator or the like will be explained below. In FIG. 4, 1 is a rotor core, and 2 is a rotor wedge. In order to explain these parts in detail, FIGS.
Use diagrams. As can be seen from these figures, a coil 3 is inserted into a slot 4 cut in the axial direction of the rotor 1, and the outer circumference of the slot 4 is designed to prevent the coil 3 from flying out due to the centrifugal force caused by the rotation of the rotor. Wedge 2 is inserted into. Although there are various shapes of the wedge 2, the wedge 2 generally has a dovetail shape as shown in FIG. 6, and other shapes such as a single shape and a Christmas tree shape are also used. These wedges 2 are cut into several pieces in the axial direction,
Therefore, at the contact surface 5 between the wedge 2 and the rotor core 1, there is always a wedge joint 6 where the end surfaces of adjacent wedges come into contact with each other. At this wedge joint 6, surface pressure is concentrated due to centrifugal force, and when the rotor bends as shown in FIG. Since a relative space ±δ occurs between the wedges and the position of the wedge joint 6 cannot be changed, 7renoting fatigue accumulates in this part, and eventually fatigue cracks are likely to occur. There were drawbacks.

Originally, there was a method of processing wedges to reduce fretting fatigue, as disclosed in %-135647 Publication, but the contact pressure on the shoulder of wedges used under mechanically severe conditions was There were disadvantages such as the need for a high level of pressure and the need for complex machining.

[Purpose of the invention]

The purpose of the present invention is to prevent the accumulation of fretting fatigue,
The object of the present invention is to provide a turbine generator rotor with high fretting fatigue strength.

[Summary of the invention]

A feature of the present invention is that a spacer is inserted between adjacent wedges. In other words, by periodically changing the position of this spacer, the position of the wedge joint can be changed in the axial direction, so that before the fretting fatigue that occurs at the wedge joint of the rotor core accumulates to the extent of crack initiation,
This fretting fatigue position can be changed to another position.

[Embodiments of the invention]

An embodiment 1t of the present invention will be described below with reference to the drawings.

FIG. 1 shows an axial section of the rotor. Double shaft end wedge 2
The position of the wedge joint 6 can be shifted in the axial direction by inserting several sets of spacers 8 having axial thicknesses different from 'l+12 between adjacent wedges and periodically replacing both spacers 8t-. In the figure, 7 is an insulating block, and 9 is a wedge caulking part.

According to the present invention, the fretting fatigue strength can be improved without increasing the surface pressure of the shoulder portion of the wedge and with relatively simple processing.

In the above embodiment, the spacer 8 may be divided into several pieces in the axial direction as shown in FIG.

Indicates the installation status. Side view and perspective view, respectively, 3rd
4 is a perspective view of a rotor of a turbine generator; FIG. 5 is an axial sectional view of FIG. 4; and FIG. 6 is a perspective view of a slot wedge assembly. 7 are diagrams showing the deformation state of the rotor.

1... Rotor core, 2... Rotor wedge, 3...
・Coil, 7... Insulation block, 8... Spacer,
9...Wedge caulking part.

Claims (1)

[Claims] 1. A rotor with a structure in which a number of axially extending slots are dug on the outer circumference of the rotor, coils are inserted into the slots, and two or more wedges are inserted into the outer circumference of the slots to fix the coils in the slots. A rotor wedge for a rotating electric machine, characterized in that a plurality of spacers having different thicknesses are sandwiched between the joints of the wedge, and a mechanism is provided to shift the joint of the wedge in the axial direction by replacing the spacers.