JPS6035896B2 - rotating electric machine - Google Patents

Description

[Detailed description of the invention] The present invention relates to a rotating electrical machine equipped with a liquid-cooled stator.

Conventional generators driven by gas turbines, for example, have a maximum rotational speed of some tens of thousands of revolutions per minute.

When cooling such a rotating electric machine, if both the stator and rotor are submerged after cooling, there is a drawback that the friction loss of the coolant in contact with the rotor is large, and in the case of a synchronous machine, the rotor's current collector system is damaged. There is a problem in that it is difficult to place the liquid in the coolant. Therefore, in what is known as a canned motor, the gap surface of the stator core is covered with a can of non-magnetic metal plates, the stator core is wrapped with wire, and the stator core is sealed, and a cooling liquid is passed through the can to cool it. However, due to manufacturing technology, the can must have a certain thickness, which increases the air gap length, and since it is made of metal, it causes a significantly large eddy current loss at high speeds, reducing efficiency and increasing the temperature. It had a drawback that made it impossible to drive. It is also possible to make the linear conductor hollow and pass liquid through it, but this would be expensive and unsuitable for small capacity machines. In addition, by applying resin such as epoxy or polyimide to the void surface of the core using a cloth-like insulating material such as glass vapor or glass cloth, or a thin cylindrical insulating material, heat-curing it, and attaching it to the inner surface of the core, a fairly thin insulator can be applied. It is possible to form layers.

However, when the temperature of the coolant and the surface temperature of the rotor rotating across the gap surface become high, the thermoset resin becomes splintered, part of the adhesive peels off, and the coolant leaks. The adhesive peels off because the adhesive splinters when it gets hot, which is the temperature limit for organic insulating materials. For this reason, a method of forming a layer by heat-sealing an inorganic insulating material, for example, a material whose main component is glass, onto the gap surface of the stator core to make it liquid-tight is considered. However, if you try to soften the gap surface of the stator core with glass material alone, the glass material will flow out of the slot during welding heat, making it difficult to close it, and once the slot is opened □. As time passes, the glass supplied to the stator core permeates into the laminated gaps of the stator core, resulting in a shortage of glass and the slot entrance cannot be closed.

In addition, even if the slot closing part can be successfully closed with a glass material, glass alone has low strength, so in rotating electric machines that are subjected to vibrations and thermal shocks, the closed part may crack, making it impractical. I can't get certain things.

The present invention has been made to eliminate the above-mentioned conventional drawbacks, and is characterized by comprising a composite body of low melting point glass that makes the entire gap surface of the stator core airtight. In particular, it is an object of the present invention to provide a rotating electric machine with a liquid-cooled stator in which the slot openings can be reliably and easily closed, are resistant to vibration and heating, and can withstand high temperatures.

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

Reference numeral 1 denotes a stator core, which is composed of laminated silicon steel plates 2, and an end plate assembly 5 formed by welding a mild steel plate 3 and a seal ring 4.

The slot opening □ part 6 and the cavity surface 7- of the iron core have 100
~200 mesh magnesia powder as aggregate and Pb0-
A layer 9 is formed by bonding with B203-Zn○ type low melting point glass.

Using a composite of low melting point glass as described above to soften the void surface of the stator core and close the slot opening, the glass material is impregnated with Honemura powder. It is possible to obtain very good drainage and occlusion because it is retained and does not flow out or become depleted.

Such processing with a composite of low-melting glass is approximately 770
This can be done at temperatures lower than the Curie point of iron.

In addition, the low-melting point glass composite has a strong bond with iron and has a coefficient of thermal expansion close to that of iron, so it does not peel or crack and has high long-term reliability. This makes it resistant to thermal and mechanical shocks, such as heat cycles of 100 to 300 qo and 5k9
/ The thickness of layer 9 is 0.
Since it is possible to fire or machine the parts below the 4th side, it is possible to obtain a product with a clean finish and extremely practical use.

A plurality of slots 10' on the inner peripheral surface of the iron core 1 are conductive wires 11 insulated with fluorine resin (trade name: Teflon, manufactured by DuPont) or silicone resin (silicone), or Thermotite wire (trade name, manufactured by Showa Dento Co., Ltd.). ) or the like is wrapped around the conducting wire 11 to form a wire wire 12.

This iron core 1 is iron-supported on a cylindrical stator side plate 13, and an annular end ring 14 is attached thereto via a "0" ring 15 so as to connect the end plate assembly 5 at the same time. Side plate 1
3 and the end ring 14 roughly put together constitutes a stator frame. Reference numeral 18 denotes a cooling liquid inlet/outlet provided in the side plate 13, which communicates with a cavity 19 at the end of the line theory.

A space 20 is formed in the slot 10 between the conductive wires 11 or between the conductive wires 11 and the slot wall, and serves as a passage for the cooling liquid. Note that 21 is a rotor. In this way, even if the temperature reaches high temperatures, the rotating electrical machine can be cooled safely and well without leaking, and has good characteristics.

As described above, according to the present invention, the sheathing layer 9 made of a composite of low-melting glass is provided on the gap surface of the stator core, particularly at the slot entrance, so that the sheathing layer 9 is made of a composite material of low-melting glass. Good cooling can be achieved without breaking the cooling liquid and leaking the circulating cooling liquid, and since the insulation layer 9 is made of a glass composite, it can be made extremely thin, making it possible to provide a rotating electric machine with good characteristics.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view showing a main part of an embodiment of a rotating electrical machine of the present invention, and FIG. 2 is an enlarged view of the main part of a cross section taken along the low-0 line. DESCRIPTION OF SYMBOLS 1... Stator core, 6... Slot opening □, 7... Gap surface, 9... Shiyahashi, layer, 10... ... Slot, 12 ... Line wheel, 18
...Cooling liquid inlet/outlet, 19...Empty room at the end of the line theory. O'zu soup Z diagram

Claims (1)

[Claims] 1. A stator core having a plurality of slots that accommodate wire rings, supporting this stator core, surrounding the outer ends of the wire rings, and having openings and exits for cooling liquid in cavities at both end portions of the wire rings. a liquid-tight stator frame; and a damping layer made of a glass composite containing aggregate and low-melting glass and adhered to the gap surface of the stator core and the slot opening. A rotating electrical machine featuring: