JPH03124236A - Dynamo-electric machine - Google Patents

Abstract

PURPOSE:To restrict transmission of vibration from a stator core to a stator frame by arranging an auxiliary rib, opposingly to each core supporting rib, between an intermediate supporting board and a shelf board so that the core supporting rib contacts with the stator core only in the central section in the axial direction, and securing the stator core and the core supporting rib at the central section. CONSTITUTION:An annular central supporting board 10 is arranged on the stator core 1 side from a shelf board 3 and welded through an auxiliary rib 11 to the shelf board 3, and then the opposite ends of a plurality of core supporting ribs 12 are welded between intermediate supporting boards 10, 10. The cylindrical stator core 1 is secured by means of through bolts 14 through washers with the outer circumferential face thereof contacting with the inside face of a core supporting rib 12 projecting from the central section. When the stator core 1 is excited in the circumferential direction, the intermediate supporting board 10, the auxiliary rib 11, and the core supporting rib 12 are deformed thus absorbing vibration of the stator core 1. By such arrangement, transmission of vibration from the stator core 1 to the stator frame 2 can be restricted.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a rotating electric machine having a stator core.

(Prior Art) FIG. 5 is a vertical cross-sectional view of the upper half of an example of a rotating electric machine having a stator core. As shown in the figure, the stator core 1 has a plurality of core support ribs attached along the axial direction between the shelf boards 3 arranged at the center of the stator core of the stator frame 2 and on both sides. 4, the outer periphery is fixed and supported by welding. In addition, the stator core 1 and the stator coil 5 are cooled by the fan 7 of the rotor 6, as shown by the arrows.
It is cooled by circulating it through the gap between the two.

In addition, the code|symbol 8 shows the wind guidance of cooling air.

(Problem to be Solved by the Invention) In a rotating electric machine having such a structure, especially in a variable speed electric motor in which the number of rotations is changed by converting the negative side power frequency using an inverter, etc., distortion of the waveform of the power supply causes problems. Due to the generated torque ripple, an excitation force having a frequency several times the power supply frequency is applied to the stator core 1 in the circumferential direction, causing it to vibrate.

This vibration is transmitted from the stator core 1 to the shelf board 3 via the core support rib 4, generating vibration noise in the stator frame 2,
He was having trouble driving.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a rotating electric machine with low vibration and low noise by suppressing the vibration of the stator core from being transmitted to the stator frame.

[Structure of the invention]

(Means for Solving the Problems) The present invention provides a rotating electrical machine in which the outer peripheral side of a cylindrical stator core is supported by a plurality of core support ribs provided along the axial direction on a shelf plate of a stator frame. , an annular intermediate support plate that supports the end of the core support rib and is provided on the stator core side with respect to the shelf plate, and an auxiliary rib that is disposed facing each other between each core support rib between the intermediate support plate and the shelf plate. The core support rib is provided with a contact portion with the stator core only at the central portion along the axial direction, and the stator core and the core support rib are fixed at that portion.

(Function) When the stator core is vibrated in the circumferential direction due to torque ripple caused by power waveform distortion, etc., the intermediate support plate, auxiliary ribs,
The core support ribs deform as shown in FIG. 4 to absorb the vibrations of the stator core 1, and the shelf plate is formed.

Suppresses vibrations from being transmitted to the stator frame.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings. FIG. 1 is a vertical cross-sectional view showing the upper half of an embodiment of the present invention, and FIG. 2 is an enlarged view of the main parts of the embodiment of the present invention shown in FIG. FIG. 3 is a top view of FIG. 2.

In these figures, the same parts as in FIG. 5 are given the same reference numerals, and their explanation will be omitted.

1 to 3, the intermediate support plate 10 has an annular shape, is disposed closer to the stator core 1 than the shelf plate 3, and is attached to the shelf plate 3 by welding via an auxiliary rib 11. Both ends of a plurality of core support ribs 12 are attached by welding between the intermediate support plates 10 and 10. Here, the auxiliary ribs 11 are arranged to face each other between the core support ribs 12. The core support rib 12 has the inner surface of the axially central portion protruding slightly from the other portions to serve as a contact surface with the stator core 1, and seat plates 13 are attached to both sides of the axially central portion by welding. There is.

Therefore, the cylindrical stator core 1 has core support ribs 12
The outer peripheral surface contacts the protruding inner surface of the above-mentioned central portion of the seat plate 13, and is fixed with a bolt 14 passing through a hole provided in the seat plate 13. In addition, an auxiliary rib 11 between the intermediate support plate 10 and the shelf board 3
A shielding plate 16 provided with one or more ventilation holes 15 is attached to the outer circumferential side of the shield plate 16, and the ventilation holes 15 are installed at the positions of the ventilation holes 15 by changing the mounting position on the shelf board 3.
Air volume adjustment plate] 7 that can change the area of 5 is installed. Note that the arrows in the figure indicate the flow of cooling air.

Next, the operation of the rotating electric machine configured as above will be explained. When the stator core 1 is vibrated in the circumferential direction due to torque ripple caused by distortion of the power supply waveform, etc., the intermediate support plate 10. The auxiliary rib 11° core support rib 12 deforms and absorbs the vibration of the stator core 1, and the shelf plate 3. Stator frame 2
to keep vibration transmission to a minimum.

The natural frequency of the core support rib 12 in the circumferential direction of the stator core 1 is ω. , if the excitation frequency in the circumferential direction of the stator core 1 is ω, then as is generally known, ω/ωn>
42, that is, ω. <If ω/42, the vibration of the stator core 1 is caused by the shelf plate 3. The transmission to the stator frame 2 can be attenuated. With the structure of the above embodiment, the thickness of the intermediate support plate 10, the core support rib 12. By changing the length and thickness of the auxiliary rib 11 and the positions of the poles 1 to 14 that fix the core support rib 12 and the stator core 1, ω can be adjusted. A, ω. It can be designed so that 〈ω/42. Thereby, transmission of vibrations of the stator core 1 to the stator frame 2 can be suppressed.

In addition, the air volume adjusting plate 17 provided on the shielding plate 16 is connected to the shelf plate 3.
By changing the mounting position of the shield plate 16, the area of the ventilation hole 15 of the shield plate 16 can be changed. As a result, after the rotating electric machine is completed, the air volume can be adjusted based on test results, making it possible to achieve an optimal air volume distribution and improve cooling efficiency. With such a structure, the core support rib 1
2. The length of the auxiliary rib 11 can be changed without affecting ventilation.

Of course, by reducing the thickness of the shielding plate 16, deformation of the stator core 1 to the intermediate support plate 10 and the auxiliary rib 1 for absorbing vibrations is not obstructed.

〔Effect of the invention〕

As explained above, according to the present invention, it is possible to design a stator core support part that suppresses transmission of vibrations to the stator frame to a low level with respect to the vibration frequency of the stator core predicted at the time of design. This makes it possible to prevent harmful vibrations and associated noise from rotating electric machines.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view showing an embodiment of the present invention with the upper half cut away, FIG. 2 is an enlarged view of the main part of the embodiment of the present invention shown in FIG. FIG. 4 is an explanatory diagram showing the operation of an embodiment of the present invention, and FIG. 5 is a vertical cross-sectional view showing an example of a conventional rotating electric machine with the upper half thereof cut away. 1... Stator core, 2... Stator frame, 3...
...Shelf board, 11...Auxiliary rib, (8733) Agent Patent Attorney 10...Intermediate support plate, 12...Core support rib. Akira (and 1 other person) 7-

Claims (1)

[Claims] In a rotating electric machine in which a cylindrical stator core is supported on its outer circumferential side by a plurality of core support ribs provided along the axial direction on a shelf plate of a stator frame, the ends of the core support ribs are supported and the An annular intermediate support plate is provided on the stator core side with respect to the shelf board, and an auxiliary rib is provided between the intermediate support plate and the shelf board to face each other between each core support rib. A rotating electric machine characterized in that a contact portion with a stator core is made only at a central portion along the axial direction, and the stator core and the core support rib are fixed at that portion.