JPS6046746A - Magnetic pole terminal board - Google Patents

Abstract

PURPOSE:To shorten the term of a work and to maintain the strength of a magnetic pole terminal board by composing a body having a dovetail of the board of a material having high mechanical strength. CONSTITUTION:A magnetic pole 1 is composed of a pole core 2, a pole terminal board 3 for pressing the core 2 from the axial end, and a field winding 4 wound on the core and the board 3, and mounted by means such as engagement of a dovetail with the outer periphery of a yoke 6 connected to a shaft 5. The board 3 is divided into a body 3a including a head and a body 3b including a dovetail 7, the body 3a employs a normal forged steel or rolled steel, the body 3b employs a nickel-chromium alloy steel having high mechanical strength, and they are coupled by an electron beam welded portion 8. Thus, the term of working can be shortened, and the board of a salient-pole rotary electric machine which can endure against high strength can be provided.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a pole end plate of a salient pole rotating electrical machine such as a water turbine generator.

[4] Technical background of the invention and its problems] In a salient pole rotating electric machine, as shown in Fig. 1, a magnetic pole (1) consists of a magnetic pole iron core (2) and a magnetic tip plate (2) that presses the magnetic pole iron core (2) from its axial end. 3) and a field winding (4) wound around these, and is attached to the outer periphery of a yoke (6) fitted to the shaft (5) by means of dovetail fitting.

By the way, as shown by the arrow in Fig. 2, all of the centrifugal force applied to the field winding during operation acts on the magnetic pole tip plate (3), so the dovetail portion (high tensile force) This generates stress and requires mechanical strength superior to that of the magnetic pole core (2).

Conventionally, this pole end plate (3) is constructed by machining the entire surface of an integrally molded material such as cast steel or forged steel.
The mechanical strength required for high-speed, large-capacity machines such as the iVA class has increased even further, and as a result, materials that are extremely difficult to commercialize, such as nickel-chromium alloy steel that has been forged into complex shapes, have to be machined. However, it was extremely expensive and took a long time to manufacture.

In order to avoid the above-mentioned problems, attempts have been made to reduce the tensile stress by increasing the size and shape of the dovetail part (force) and using ordinary forged steel, which is easily available on the market, but in this case, Not only does the amount of magnetic pole iron (2) used increase accordingly, but the yoke (to which the magnetic pole (1) is attached) also increases.
Since the depth of the dovetail groove 6) also increases, the effective cross section of the yoke (6) that should support centrifugal force decreases, and to compensate for this, it becomes necessary to increase the axial length of the yoke (6). As a result, there was an inconvenience that the economic efficiency was severely impaired.

OBJECTS OF THE INVENTION The present invention has been made in view of the above points, and an object of the present invention is to provide a pole end plate for a salient pole type rotating electrical machine that can be manufactured in a short period of time and can withstand high stress.

[Summary of the invention]

The present invention aims to shorten the construction period and maintain the strength by constructing the body including the dovetail portion of the pole tip plate from a steel having high mechanical strength.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described with reference to FIG. In FIG. 3, a body (3a) including the head of the pole tip plate (3) and a body (3b) including the dovetail portion (6).
The body (3a), which includes the head, is made of conventional forged steel or rolled steel, and the body (3b), which includes the tarp tail, is made of nickel, which has high mechanical strength. Using chromium alloy steel or the like, these are joined by, for example, an electron beam weld (8).

In such a magnetic pole tip plate, only the body including the dovetail portion is made of alloy steel with high mechanical strength, so that the required strength can be maintained without increasing the size and shape of the dovetail portion.

In this way, the part of the alloy steel with high mechanical strength can be cut into a simple plate shape without a complicated shape, and therefore the marketability is greatly improved.

Furthermore, since the range of use of expensive alloy steel can be kept to the minimum necessary, it is possible to realize a cost reduction that is more than enough even if the cost increase due to welding of the body is discounted.

Furthermore, as shown in FIG. 5, by selecting the connecting part close to the head, both the body part (3a) including the head part and the body part (3b including the dovetail) are made of plate materials (9a) and (9b), respectively.
This becomes possible when the two are constructed from the same material, and even if both are manufactured with the same quality, it is possible to improve economic efficiency.

[Effects of the Invention] As described above, the present invention has an advantage in that the manufacturing period is short and the product can withstand high stress. A magnetic pole end plate for a rotating electric machine can be provided.

[Brief explanation of drawings]

Figure 1 is a sectional view showing the main parts of the rotor of the ultimate rotary tonnage machine.
FIG. 2 is a perspective view showing the tip of the blade, FIGS. 3 and 4 are perspective views showing a magnetic pole tip plate according to one embodiment of the present invention, and FIG. 5 is a perspective view showing another embodiment. l...Magnetic pole 2...Magnetic pole iron core 3...Magnetic end plate 3a...Body portion 3b including the head...
・Body part including dovetail part 4... Field winding s 5... Shaft 6... Yoke 7... Dovetail part 8... α electron beam welding part 9a+9b... Plate material agent Patent Attorney Noriyuki Chika (and 1 other person) Figure 1 Figure 2 Figure 3/ Figure 4 Figure 5

Claims (1)

[Claims] What is claimed is: 1. A magnetic pole tip plate having a dovetail portion, a body portion, and a head portion, wherein at least a portion of the body portion including the dovetail portion is formed of a material having higher mechanical strength than other portions.