JPS5849056A - Braking coil for rotary electric machine - Google Patents

Abstract

PURPOSE:To increase the mechanical strength of a braking coil for a rotary electric machine by clamping and fixing damper plates and connecting pieces with a nut secured to a pole end plate and a clamping bolt, thereby preventing the occurrence of cracks at the damper plates. CONSTITUTION:Ends of a plurality of damper bars 5 extending axially at the prescribed interval toward the peripheral direction in the vicinity of the surface of a pole end plate 6 are shortcircuited therebetween by soldering them with a damper plate 2, thereby connecting the damper plates 2 of the adjacent poles through connecting pieces 4 and forming a braking coil. In this case, the ends of the damper plates 2 and the piece 4 are superposed, and are clamped fixedly by a nut 3a secured to the plate 6 and a clamping bolt 1, thereby supporting the plate 2 at both sides.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a damper winding of a rotating electrical machine, and particularly comprises a damper bar, a damper plate, a connecting piece, etc., and the damper plate and the connecting piece are connected by fastening bolts and nuts. This relates to the brake windings of rotating electric machines.

For example, a damper winding in a rotor of a water turbine generator is constructed by connecting the ends of a plurality of damper bars extending in the axial direction at predetermined intervals in the circumferential direction near the surface of a ball end plate with a damper plate. It is configured with a short circuit and is used to absorb the reverse phase component of an unbalanced load or abnormal voltage during an unbalanced short circuit. A conventional example of such a brake winding for a rotating electrical machine is shown in FIGS. 1 and 2. In this damper winding, a plurality of damper bars 5 extend in the axial direction at predetermined intervals in the circumferential direction near the surface of the ball end plate 6.
The ends thereof are short-circuited by brazing the damper plate 2 or the like. The end of this damper plate 2 is connected to the damper plate 2 of the adjacent ball via a connecting piece 4, and is formed into a ring shape as a whole.
The end of the damper plate 2 and the connecting piece 4 are connected as shown in FIG. That is, the end of the damper plate 2 and the connecting piece 4 are overlapped and connected by tightening bolts l and nuts 3. However, as shown in FIG. 2, the connection between the fastening bolt 1 and the nut 3 is separated from the ball end plate 6, and the damper plate 2 is fixedly supported only on one side. It was supported on a cantilever. Therefore, due to the centrifugal force and electromagnetic vibration caused by rotor operation, the fastening bolt 1
A large force is applied to the damper plate 2 at the connection portion by the nut 3, and there is a concern that cracks may occur. If a crack occurs in the damper plate 2, the damper per 5 will also be damaged and will eventually lose its function as a damper winding.

The present invention has been developed in view of the above points, and its object is to provide a brake winding for a rotating electrical machine that prevents the occurrence of cracks.

That is, the present invention is characterized in that the nut is fixed to the opposing ball end plate.

The present invention will be explained below based on the illustrated embodiments. FIG. 3 shows an embodiment of the present invention. Note that parts that are the same as those in the conventional model are given the same reference numerals, and therefore their explanations will be omitted. In this embodiment, the nut 3a is fixed to the opposing ball end plate 6. That is, the end of the damper plate 2 and the connecting piece 4 were overlapped and fixed by tightening with a nut 3a fixed to the ball end plate 6 and the fastening bolt 1. By doing this, the damper plate 2 is fixed to the ball end plate 6 by the nut 3a at the connection part by the fastening bolt 1, so that the end plate 2 is fixedly supported at both ends. This improves mechanical strength, withstands centrifugal force and electromagnetic vibration caused by rotor operation, and prevents cracks from forming. The natural frequency of the damper plate 2 due to this support on both sides is approximately 10 times that of the conventional damper plate, and the overall size can be reduced.

As described above, in the present invention, the nut is fixed to the opposing ball end plate, so that the connection part of the damper plate by the fastening bolt is fixedly supported by the ball end plate, and both ends of the damper plate are fixedly supported. Since the ends are supported on both ends, the mechanical strength is improved and the occurrence of cracks is prevented, and it is possible to obtain a brake winding for a rotating electrical machine that prevents the occurrence of cracks.

[Brief explanation of the drawing]

Figure 1 is a perspective view of the rotor main part of the brake winding of a conventional rotating electrical machine, Figure 2 is a side view of the brake winding of a conventional rotating electrical machine, and Figure 3 is a side view of the brake winding of a conventional rotating electrical machine.
The figure is a side view of one embodiment of a brake winding for a rotating electric machine according to the present invention. 1... Fastening bolt, 2... Damper plate, 3
a... Nut, 4... Connection piece, 5... Damper, 6... Ball end plate.

Claims (1)

[Claims] 1. A plurality of damper bars extending in the axial direction at predetermined intervals in the circumferential direction near the surface of the ball end plate, a damper plate that short-circuits the ends of these damper bars, and this damper plate. a damper plate and a connecting piece, the damper plate and the connecting piece are connected by a fastening bolt and a nut, in a damping winding of a rotating electrical machine, the nut is fixed to the opposing ball end plate. A brake winding for a rotating electric machine, which is characterized by: