JPS5840899B2 - rotor of rotating electric machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rotor of a rotating electric machine such as a turbine generator, and more particularly to a device for adjusting thermal balance using a wedge.

Generally, in the rotor of a large rotating electric machine such as a turbine generator, ventilation holes are provided in the rotor windings and wedges.
A cooling medium such as hydrogen gas is passed through these ventilation holes to enhance the cooling effect.

FIG. 1 is a sectional view of a main part of a rotor that employs such a direct cooling method.

In this figure, 1 is a rotor core, 2 is a slot provided on the outer periphery of the rotor core, and 3 is a tooth formed between the slots 2.

A rotor winding 4 is housed in the slot 2 and is composed of a large number of coil conductors 5 and ground insulation 6 provided around the coil conductors 5. A ventilation hole T is formed in the coil conductor 5.

8 is an overlay made of an insulating material, and 9 is a metal wedge consisting of a large number of wedge pieces divided in the axial direction, which holds the rotor winding 4 in the slot through the overlay 8. The wedge 9 is formed with ventilation holes 10.11 on the suction side and the exhaust side, respectively, which communicate with the ventilation holes 7 of the rotor winding 4.

Therefore, as shown by the arrow, the cooling medium enters through the ventilation hole 11 of the wedge 9, passes through the ventilation holes 10 and 7 of the overlay 8 and the rotor winding 4, cools the coil conductor 5, and then passes through the overlay 8 and the ventilation holes 10, 7 of the rotor winding 4.
The air is discharged from the rotor through other ventilation holes 10.11 (indicated by broken lines) of the wedge 9.

By the way, such wedges made up of a large number of wedge pieces have conventionally been arranged and fixed as shown in FIG.

That is, on the surface of each tooth 3 between each slot 2 in the rotor core 1, there are caulking grooves 1 extending in the circumferential direction at every plural wedge pieces (three in this figure) in the axial direction.
2, and each wedge piece 9a is sequentially arranged at the opening of the slot with a gap 13 between each other.
j 9b I Of the 9cts 9d, 9e..., the portions of the wedge pieces 9a, 9d located at positions corresponding to the caulking grooves 12 and facing the caulking grooves 12 are hammered out into the caulking grooves 12 to form the caulking portions 14. , this caulking portion 14 and caulking groove 12
This engagement prevents the groping pieces 9a, 9d from moving in the axial direction.

In addition, in the figure, 15 is a rotating shaft, and 16 is a holding ring.

Moreover, if the gap 13 between the groping pieces is too thick, the groping piece 9b between the groping pieces 9a and 9d fixed in the axial direction
, 9c move freely between the gaps 13 and shift in the axial direction, causing the relative positions of the ventilation holes 7 of the rotor winding 4 and the ventilation holes 11 of the groping pieces gb, 9c in the axial direction to shift, and the amount of ventilation to be reduced. If the gap 13 is too small, the respective probe pieces 93 to 9e will press against each other due to the difference in thermal expansion between the probe pieces and the rotor core, and if the gap 13 is too large. Similarly, is it the ventilation hole 7 of the rotor winding 4 and the groping piece?

The relative position of 9c with the ventilation hole 11 in the axial direction is shifted and the cooling effect deteriorates, so when the rotor temperature rises, the respective groping pieces 9a to 9e come into contact with each other and the gap 13 becomes zero. It is normal to set it as follows.

On the other hand, inside the rotor, heat flows to the rotor windings due to a gap between the shafts that occurs as the rotor core increases in temperature, and uneven heat circuits due to variations in the thickness of the paint applied to the rotor surface. As the current increases, a thermal imbalance occurs that increases shaft vibration, and shaft vibration cannot be reduced simply by achieving mechanical balance.

Therefore, the groping piece located at a position radially symmetrical to the part where the thermal imbalance occurs is forcibly moved in the axial direction.
The relative position of the ventilation hole and the ventilation hole of the rotor winding in the axial direction is shifted to reduce the amount of air flowing through the rotor winding, thereby creating a thermal imbalance in this area. Recently, a method has been proposed in which the above-mentioned thermal imbalance is canceled out and balanced by balance.

However, when applying such a balance method to a rotor having the structure shown in Fig. 2, it is necessary to adjust the spacing 13 between each groping piece in order to generate a thermal imbalance. Even if the pieces 9b, 9c, and 9e are moved in the axial direction, the gap 13 between the pieces is set to zero when the temperature of the rotor increases, so the thermal expansion of each piece, Due to repeated thermal contraction, each probe that was moved in the axial direction to create thermal imbalance returns to its original position, making it impossible to maintain thermal balance.

The present invention has been made in view of these points, and its purpose is to provide a rotor for a rotating electrical machine that can maintain thermal balance by adjusting the axial position of the groping piece.

In order to achieve this object, the present invention makes at least one of the gaps formed between the respective groping pieces an airflow adjustment gap having a larger width in the axial direction than the other gaps. The axial position of the groping piece was adjusted by the increase in axial width relative to other gaps to maintain thermal balance, and then the groping piece adjacent to the ventilation volume adjustment gap was fixed so as not to move in the axial direction. Features.

An embodiment of the present invention will be described below with reference to FIG.

In FIG. 3, the same reference numerals as in FIG. 2 indicate the same or equivalent parts.

In this embodiment, instead of the conventional caulking groove 12 formed at each location of each tooth 3 (at every third groping piece) shown in FIG. A pair of caulking grooves 12a and 12b are formed at intervals in the axial direction, and a gap, that is, a groin, is formed between the pair of caulking grooves 12a and 12b. The gaps between the pieces 9a and 9b and between the pieces 9d and 9c are set to be larger than the other gaps 13 by an adjustment α as gaps 17 for adjusting the ventilation amount.

To maintain heat balance in this rotor, do the following:

First, each groping piece 9a~ inserted into the opening of the slot 2.
By adjusting the axial position of 9e, the general gap 13 becomes almost zero as the groping pieces 9a to 9e come into contact with each other when the rotor temperature increases due to operation, as in the conventional example described above. In addition, the ventilation volume adjustment gap 17 is made larger than the general gap 13 by the adjustment α, and in this state, the positions corresponding to each pair of caulking grooves 12a, 12b are set. In other words, the side portions corresponding to the caulking grooves 12a t 12b of the groping pieces 9a, 9b; 9d, 9e located adjacent to the ventilation amount adjustment gap 17 are caulked grooves 12a.

12b to form a caulking portion 14, and by engaging the caulking portion 14 with the caulking grooves 12a, 12b, each of the groping pieces 9a, 9 adjacent to the ventilation amount adjustment gap 17 is removed.
b, 9d, and 9e are fixed so that they do not move in the axial direction.

Next, the rotor winding 4 is actually energized to rotate the rotor, and if an unbalance that increases shaft vibration occurs due to thermal factors inside the rotor, the rotor After stopping, deform the caulking portions 14 of the groping pieces (for example, 9b, 9d) located at radially symmetrical positions around the rotational axis to the portion where this thermal imbalance has occurred so as to come out of the caulking groove. Then, the caulking portion 14 and the caulking groove are released from each other, and the groping piece (for example, 9b) is removed.

9G, 9d) is moved in the axial direction within the range of the adjustment valve α of the ventilation amount adjustment gap 17, and the groping piece (for example, 9b) is moved in the axial direction within the range of the adjustment valve α of the ventilation amount adjustment gap 17.

By shifting the relative positions of the ventilation holes 11 of 9C and 9d) and the ventilation holes 7 of the rotor winding 4, the amount of air flowing through the rotor winding 4 at the symmetrical position is reduced, thereby creating a thermal imbalance in this area. This thermal imbalance is used to cancel out the thermal imbalance and maintain thermal balance.

In addition, each groping piece that moves at this time (for example, 9'b, 9c,
It goes without saying that the gap 13 between 9d and 9d) should be set so that when the rotor temperature rises, each of the groping pieces (for example, 9b, 9c, 9d) comes into contact with each other and the gap 13 becomes almost zero, as before the adjustment.

After the thermal balance is achieved, the side of the groping piece (for example, 9 b l 9d ) that has been moved after disengaging from the caulking groove, facing the caulking groove (for example, 12b, 12a), is inserted into the caulking groove again. A caulking portion 14 is formed by hammering out the material, and this is engaged with the caulking groove to be fixed so as not to move in the axial direction.

As a result, each of the moved groping pieces (for example, 9b, 9C,
9d) is held at the position after the movement adjustment, and the other groping pieces are held at their original positions before adjustment.

As described above, according to the present invention, the thermal balance of the rotor can be easily maintained by adjusting the axial position of the groping piece.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part of a direct cooling rotor, FIG. 2 is a partially cutaway perspective view showing a rotor of a conventional turbine generator, and FIG. 3 is a turbine generator according to an embodiment of the present invention. FIG. 2 is a partially cutaway perspective view showing the rotor of FIG. 1...Rotor core, 2...Slot,
3...teeth, 4...rotor winding,
7... Winding ventilation hole, 9a to 9e... Groping piece, 11... Wedge ventilation hole, 12a. 12b... Caulking groove, 13... Wedge gap, 14... Wedge caulking portion, 17... Ventilation amount adjustment gap.

Claims (1)

[Scope of Claims] 1. A rotor core having a large number of slots on the outer periphery, a rotor winding having a ventilation passage wound in the slots of the rotor core, and a rotor winding having a plurality of slots wound in the slots of the rotor core. and a wedge held in the rotor winding, the wedge being composed of a plurality of wedge pieces divided in the axial direction, and the wedge piece being provided with a ventilation passage communicating with the ventilation passage of the rotor winding. in which at least one of the gaps formed between the wedge pieces is a ventilation volume adjustment gap having a larger axial width than the other gaps, and the wedge element adjacent to the ventilation volume adjustment gap is A rotor for a rotating electric machine, characterized in that one piece is fixed so as not to move in the axial direction. 2. In claim 1, the wedge element piece is fixed in the axial direction by a caulking groove extending in the circumferential direction provided on the outer periphery of the rotor core, and a wedge element protruding into the caulking groove. A rotor for a rotating electric machine, characterized in that the rotor is engaged with a caulked portion of one piece.