JPS6192138A - Seam position altering method of rotor wedge in rotary electric machine - Google Patents

Abstract

PURPOSE:To prevent a core from excessively storing a fatigue by exchanging a wedge inserted to the end of a slot of a rotor core with a wedge having different length, and displacing the seam position of the wedge, thereby altering the storing position of a frett ing fatigue of the core. CONSTITUTION:When wedges 5a-5g divided into a plurality of pieces are inserted longitudinally to the slots of a rotor core 1 to retain a coil 3, the wedges 5a, 5b disposed at the outermost end are exchanged with wedges having different lengths at a suitable timing to alter the seam position of the wedges. To this end, the lengths L1-L3 of the wedges 5a, 5b, 5g of the end are, for example, differentiated, the wedges inserted initially as shown in Fig. 1 (a) are inserted to the right end as shown in Fig. 2 (b) by pulling the wedge 5a of the left end, and preferably altered.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a wedge joint position changing method for reducing fretting fatigue occurring in a rotor core at the contact surface end of a rotor wedge in a rotating electric machine.

(Blue Tatami of Invention) In the rotor of a rotating electric machine such as a turbine generator, fretting fatigue accumulates in the rotor core due to the sliding motion of the wedge inserted into the slot and the slot inner wall, and eventually fatigue wears out. There is a problem that fretting fatigue is more likely to occur.The occurrence of this fretting fatigue and measures to reduce it are disclosed in Japanese Patent Application Laid-Open No. 135647/1982, but local accumulation of fatigue cannot be avoided. .

[Purpose of the invention]

An object of the present invention is to provide a method for changing the joint position of a rotor wedge in a rotating electrical machine that can avoid local N products of fretting fatigue and prevent fatigue cracks from occurring.

[Summary of the invention]

In order to achieve this object, the present invention provides a rotor for a rotating electric machine including a plurality of wedges arranged in the axial direction for one slot, in which the wedges located at the ends of the slots have different lengths. By replacing the wedge with a wedge, the position of the wedge joint in the slot is changed, thereby reducing the flex that occurs in the rotor core at the edge of the wedge contact surface.

It is characterized by dispersing the locations where fatigue accumulates to prevent excessive fatigue from accumulating locally.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

As shown in FIGS. 2 to 4, the rotation f of the turbine generator is determined by the fact that a slot 2 in the axial direction is formed on the outer periphery of the rotor core 1, and a coil 3 housed in the slot 2 is rotated outside. In this structure, an insulating block 4 and wedges 5s, 5b, . . . are inserted. The wedges 5a, 5b, etc. are used to prevent the coil 3 from flying out due to the centrifugal force generated by the rotation of the rotor, and are dovetail shaped in this embodiment, but may also be T-shaped, Christmas tree shaped, etc. be. .

As the rotor rotates, the centrifugal force generated in the coil 3, insulating block 4, and wedges 5a, 5b... It is received by the contact surface 6. Moreover, the surface pressure of this contact surface 6 is
..., that is, near where the joint 7 of the wedges 5a, 5b, etc. is located.

On the other hand, when a long rotor of this kind is placed in the machine and supported by bearings at both ends, the rotor bends due to its own weight using the bearings as a fulcrum as shown in FIG. 5. 9
is the bearing, r is the radius of curvature of the rotor, r is the radius of the rotor, L is the length of the wedges 5a, 5b, etc., 1. is the length of the wedge storage area when the wedges 5a, 5b, etc. are stored in the slots when the rotor is straight, and j is the length of the wedge storage area contracted by the deflection of the rotor. The dimension 1t is the length dimension of the wedge storage area expanded by the deflection of the rotor, and δ is the amount of expansion and contraction of the wedge storage area.

When the rotor is in this state while rotating, the length dimension of each wedge storage area in each slot 2 is! ,~1m
<-js±6).

On the other hand, since the changes in the length dimensions of the wedges 5a, 5b, etc. are negligible, the inner wall of the slot 2 at the end of the wedges 5a, 5b,... A slip of ±δ occurs on the contact surface 6 of 5b, and fretting fatigue occurs in this portion.

By the way, in this embodiment, the wedges 5a, 5b, . Wedge 5 of L+, L+ (I-1 boo L2)
a, 5b, and a longer M method on the other end,
Cut 5 g of wedge into Ce, n.

When a certain degree of fretting fatigue is accumulated in the rotor core 1 at the wedge joint position due to rotation of the rotor, the wedge 5a at the left end is pulled out and inserted from the right side into the wedge 5g at the right end, as shown in FIG. (By rearranging the wedges as shown in bl, each wedge 5a, 5b...
・Change the seam position.

As a result, fretting fatigue M in the rotor core 1
! Since one position has changed, the accumulation of fretting fatigue at the initial wedge seam position is stopped. When a certain degree of fretting fatigue accumulates at the new wedge joint position resulting from this rearrangement of the wedges, the wedge 5b at the left end is pulled out and inserted from the right side of the wedge 5a at the right end to change the wedge joint position again.

In this way, the fretting fatigue accumulation position with respect to the rotor core l is sequentially changed, so that fretting fatigue is not accumulated at a specific wedge joint position, and Vt is maintained for a long period of time. Fatigue failure is prevented.

In addition, various modifications can be considered to this method of keeping Wedge. Some examples are explained below.

(a) Sum of the lengths of the wedges at both ends. Separate wedges with the same and different ratios are used and replaced.

(b) Place wedges whose ratio is equal to the sum of the lengths of the sea urchin fins at both ends and whose ratio differs from each other to another slot ([1), and replace these wedges with those of another shaft.

(c) Replace the wedge at one end of each slot with the wedge at the other end.

Furthermore, the shape of the wedge is not limited to one in which the entire surface of the wedge contacts the inner wall surface of the slot, but a part of the wedge can be in contact with the inner wall surface of the slot, and the same effect as e) can be obtained.

〔Effect of the invention〕

According to the present invention, the edge located at the end of the slot is replaced with another wedge of different length to change the position of the sea urchin and the sea urchin in the slot. Therefore, excessive accumulation of fretting fatigue in the rotor core at a specific wedge joint position can be prevented.

Drawing l! The explanatory drawings show one embodiment of the present invention, and the 1st U! Jla
1 and fbl are explanatory diagrams of wedge arrangement, Fig. 2 is an external perspective view of the rotor, Fig. 3 is a longitudinal cross-sectional end view thereof, Fig. 4 is a partially enlarged perspective view thereof, and Fig. 5 is an explanatory diagram of occurrence of fretting fatigue. It is.

...Rotor core, 2...Slot, 3...
Coil, 5a to 5g...Wedge, 6...Contact surface, 7...Wenge dark blue.

Figure 1 (b) Figure 2

Claims (1)

[Claims] 1. A plurality of slots formed in the rotor core, a coil housed in these slots, and a coil placed in the slot on the outer circumferential side of the coil to hold the coil in the slot. A rotor in a rotating electric machine including a plurality of wedges inserted and arranged in the axial direction,
A method for changing a joint position of a rotor wedge in a rotating electrical machine, characterized in that the wedge located at the end of the slot is replaced with another wedge of a different length to change the position of a wedge joint within the slot. 2. In claim 1, the length of the wedge at one end of the slot is different from that of the other wedge, and the wedge at one end is replaced with the other end to form a wedge joint. A method for changing the joint position of a rotor wedge in a rotating electric machine, the method comprising changing the position. 3. In claim 1 or 2, a plurality of wedges having different lengths are located at one end of the slot, and the wedges are sequentially placed at the other end starting from the wedge at the most side end. A method for changing a rotor wedge seam in a rotating electric machine, the method comprising changing the wedge seam position by replacing the rotor wedge. 4. According to claim 1 or 2, the lengths of the wedges at both ends of the slot are made different from those of other wedges, and the wedge joints are formed by replacing and arranging the wedges. A method for changing the joint position of a rotor wedge in a rotating electric machine, the method comprising changing the position. 5. In claim 1, the wedges at both ends of the slot have different lengths from other wedges, and the wedges at both ends have the same sum of lengths and different ratios. A method for changing the joint position of a rotor wedge in a rotating electric machine, the method comprising changing the joint position of a rotor wedge by replacing the wedge with another wedge. 6. The rotation according to claim 1 or 5, characterized in that the wedge joint position is changed by exchanging the wedge at the end of one slot with the wedge at the end of another slot. How to change the joint position of rotor wedge in electrical machinery.