JPH02269437A - Magnetizing method field system of rotary electric apparatus - Google Patents

Abstract

PURPOSE:To magnetize a permanent magnet of a rotor by using a frame of a rotary electric apparatus doubling also as a yoke for magnetization, by fitting a field pole for magnetization in a space formed between the inner peripheral part of this frame and the outer peripheral part of the rotor before incorporating a stator and by exciting the field pole thereafter. CONSTITUTION:A frame 9 of a rotary electric apparatus is used also as a magnetizing yoke of a magnetizing device. Next, a field pole of a magnetizing device provided separately is fitted by making use of a space 13 formed between the inner peripheral part of the frame 9 and the outer peripheral part of a rotor. An exciting power is supplied to a field pole coil 12c, so as to magnetize a permanent magnet which is opposite to the coil and not yet magnetized. According to this method, it is quite unnecessary to be concerned about demagnetization of the permanent magnet in shrinkage fit.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is applicable to, for example, a field (permanent magnet) of a rotating field type rotor in a high-speed rotating electric machine such as a gas turbine generator.
The present invention relates to a method of magnetizing a field of a rotating electric machine, which enables magnetization of a rotating electrical machine in an inexpensive and simple manner.

[Prior Art] A conventional rotating electric machine such as a turbine generator, for example,
It was configured as shown in the figure.

That is, first of all, a one-rotation field type rotor has permanent magnets for the field, for example, two-pole permanent magnets 2a and 2, for the two-rotation shaft 1.
b is attached with an adhesive via spacers 3a and 3b, and a shrink ring 4 is fitted between the permanent magnet and the spacer by shrink fitting.

Note that 4a and 4b are balance discs, 5° 5' is a bearing, 6 is a compressor, and 7 is a turbine blade.

Also, on the stator side, stator 8. Frame 9. It is composed of an end cover 10 and the like. Note that the left end cover and the structure for supplying cooling air to the blades 7 are not shown because they are not directly related to the present invention.

[Problems to be Solved by the Invention] In the conventional system, permanent magnets for the field are purchased in advance and magnetized using a separately installed magnetizing device, and then installed in the single rotor. was. For this reason, expensive permanent magnets were required.

Furthermore, in the conventional structure, the permanent magnet was directly shrink-fitted and fixed to the rotary shaft using the shrink ring 4, as described above, and therefore there was a primary problem.

In other words, since the temperature difference between the one-rotation shaft 1 and the permanent magnets 2a, 2b is not very large, if the initial offset is set to just enough to provide rigidity between the one-rotation shaft 1 and the permanent magnets 2a, 2b, Heat it up.

I had to shrink fit the shrink ring.

However, permanent magnets generally have the property of being demagnetized at temperatures above 200°C, so if you heat them at such high temperatures to shrink-fit a shrink ring,
The drawback was that the permanent magnet demagnetized, reducing performance.

Taking this into consideration, it is possible to make the initial shimmy slightly smaller than the above value and lower the heating temperature during shrink fitting, but if you do this, the rotor will become double-rotated when operated at high speed. Even if there is a very small gap between the objects to be fitted, such as permanent magnets or shrink links, an unbalance will occur in the single rotor, making it impossible to pass the critical speed of the lower axis, or There was a fear that a situation where vibration would also occur would occur.

Therefore, in the conventional case, the actual situation was to strongly magnetize the permanent magnet in anticipation of some degree of demagnetization.

[Means for Solving the Problems] The present invention aims to eliminate the drawbacks of the conventional example, and for this purpose, the frame of a rotating electric machine is also used as a magnetizing yoke, and the inner peripheral part of this frame is After attaching magnetizing magnetic poles to the space formed between the rotor and the outer periphery of the rotor before the stator is assembled, the permanent magnets of the rotor are magnetized by energizing the magnetic poles. The present invention relates to a method of magnetizing a field of a rotating electrical machine.

[Example 1] The magnetization method of the present invention will be described below according to an example shown in FIG.

In the magnetization method of one embodiment of the present invention, an unmagnetized permanent magnet 1
spacers 3a, 3 using spacers 1a, llb as in the conventional example.
b. Shrink ring 4. Balance discs 4a, 4b
After setting the rotor configured in the yoke 9, 1
Set the magnetizing device so as to face the permanent magnets of the rotor as follows.

(2) The frame 9 of a nine-rotary electric machine is also used as the magnetizing yoke of the magnetizing device.

■Next, the magnetic poles 12a and 12b of the separately provided magnetizing device (the excitation power source is installed separately and only the coil 12c is shown) are connected to the space created between the inner circumference of the frame 9 and the outer circumference of the rotor. Attach using location 13.

(2) Supplying excitation power to the magnetic pole coil 12c and magnetizing the opposing unmagnetized permanent magnet.

Note that the 1 magnetizing yoke also serves as a frame for magnetization, so
It is necessary to design the cross-sectional area of the frame so that the magnetic flux density does not become too high.

Further, in this embodiment, the case of magnetizing an unmagnetized permanent magnet will be explained, but the present invention can also be applied to magnetization for supplementary magnetization of a permanent magnet that has already been magnetized.

[Function] In the magnetizing method of the present invention, the permanent magnets 2a2b of one rotor are magnetized in the order of 1.about.2 as explained in the section of the embodiments above.

In this case, since it is now possible to use an unmagnetized permanent magnet as the permanent magnet of the rotor that has already been assembled, the permanent magnet can be heated with the shrink ring 4 when assembling the first rotor. There is no longer any risk that the permanent magnet will be demagnetized even if it is exposed to high temperatures when it is fitted and installed.

[Effects of the Invention] The magnetization method of the present invention utilizes the steps before inserting the stator and performs them in the order described above, so it has excellent zero-order effects.

■Yoke on the stator side Since it is also used as the magnetizing yoke of the magnetizing device, the number of constituent elements can be reduced accordingly.

Using an unmagnetized permanent magnet as the permanent magnet of the 0 rotor,
When the shrink ring is shrink-fitted, there is no need to worry about demagnetization of the permanent magnet during shrink-fitting.

■Since unmagnetized products can be used as permanent magnets, machining time and balancing time can be shortened, making it possible to manufacture two-rotation electric machines at low cost.

[Brief explanation of drawings]

Fig. 1 shows a rotating electric machine to which the present invention is applied, in which (a) is a half longitudinal sectional front view, and (b) is a BB' of (a).
Figure 2 is a cross-sectional view of the entire rotor taken along the line, showing a conventional example, in which (a) is a half longitudinal front view, and (b) is the entire rotor taken along line A-A' in (a). FIG. Yoku 11b = Permanent magnet (unmagnetized) 2a 2b Magnetic pole: Blank space

Claims (1)

[Claims] 1. The frame of the rotating electrical machine also serves as a magnetizing yoke, and for the space formed between the inner circumference of the frame and the outer circumference of the rotor before the stator is assembled. 1. A method for magnetizing a field of a rotating electrical machine, characterized in that, after attaching magnetic poles for magnetization, permanent magnets of an assembled rotor are magnetized by exciting the magnetic poles. 2. Shrink rings are shrink-fitted onto unmagnetized permanent magnets to form a rotor, and the unmagnetized permanent magnets are magnetized by excitation of the magnetic poles. A method for magnetizing a field of a rotating electric machine according to claim 1.