JPH0427789B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a liquid-cooled rotating electric machine, and particularly to a stator cooling structure.

[Technical background of the invention]

Figure 1 shows a conventional vertical shaft type liquid-cooled rotating electric machine, in which a stator 2 fixed to a frame 1 is connected to a laminated iron core of a rotating shaft 5 supported by a bearing 4 on the frame 1 via a water gap 3. As the rotor 6 rotates, the pump 7 installed below the rotary shaft 5 sends the coolant upward to seal the inside of the machine, and the coolant passes through the water gap 3 between the stator 2 and the rotor 6 and reaches the stator. It descends through the heat dissipation section 8 between the iron core 2 and the frame 1, returns between the guide 9 and the frame 1, and circulates. In addition, the stator 2 has stator windings 11 inserted into slots of stator cores 10 stacked as shown in FIG. 2 through stator wedges 12.
A gap 13 is formed between the stator core 10 and the stator winding 11. Cooling water flows from pump 7 to gap 13 and water gap 3 as shown by the arrow.
The stator 2 and the rotor 6 are cooled through the heat dissipating section 8, and then returned to the pump 7 along the guide 9 for circulation.

[Problems with background technology]

However, with such a structure, as the stator core 10 becomes longer, the temperature of the water coming out of the water gap 3 increases significantly, and only this temperature rise surface increases the stator 2.
The temperature of the rotor 6 increases, and the temperature in the axial direction increases. In order to deal with this, there is a conventional method in which the cooling water is directed radially inward from the axial center of the stator 2 and flows into the water gap 3, but although the cooling effect is improved, mechanical loss increases significantly and efficiency is reduced. There were drawbacks such as a decrease in

[Object of the Invention] The present invention was made in view of the above-mentioned drawbacks, and an object of the present invention is to provide a liquid-cooled rotating electric machine in which the axial temperature difference between the stator and rotor is small and the mechanical loss is reduced.

[Summary of the invention]

In order to achieve the above object, the present invention provides a liquid-cooled rotating electric machine in which a liquid to be sealed inside the machine passes axially inside a stator core and circulates back outside. A radial duct is arranged and formed at one or more places in the axial direction, and the entire inner peripheral surface side of the radial duct is closed between the stator wedge for holding the stator winding and the spacer. By fixing the stuffing with stator wedges, stator windings, or spacers, cooling water can pass through the gap between the stator core and stator windings.
The remaining portion exits to the back of the stator core through the radial duct provided in the axial direction and radiates heat, and the remaining portion exits from the upper end of the stator core to the back of the stator core to radiate heat.
In the present invention, the passage of cooling water passing through the water gap between the stator and rotor and the passage of cooling water passing through the gap and radial duct are provided independently, so that the axial temperature of the stator and rotor increases. The difference is small, and it is possible to reduce mechanical loss and increase the cooling effect.

[Embodiments of the invention]

An embodiment of the present invention shown in the drawings will be described below. In FIGS. 3 and 4, parts having the same functions as those in FIGS. 1 and 2 are given the same reference numerals, and explanations thereof will be omitted. 14 is 1 in the axial direction of the stator core 2.
It is a radial duct provided at one or more locations, and is formed by radially arranging spacers 15, and on the rotor 6 side, stator wedges 12 and stator windings 11 prevent water from leaking. The stuffing 16 is fixed to the.

Next, the effect will be explained. Cooling water flows from the pump 7 to the upper part of the frame 1 through the water gap 3 and the gap 13 as shown by the arrows, and from the gap 13 through the radial duct 14 to the back of the stator core 10. Since the rotor 6 is cooled, the cooling area of the stator 2 is greatly increased, the cooling effect is increased, and the temperature difference in the axial direction is reduced.
Furthermore, due to the filling 16, the increase in stirring loss caused by the rotation of the rotor 6 is small.

FIG. 5 shows another embodiment in which the shape of the padding 16 is U-shaped or I-shaped to minimize irregularities on the inner wall surface of the stator 2, thereby reducing stirring loss due to rotation of the rotor 6. It can be made even smaller. Further, the spacer 15 may be provided with a circumferential round hole, an elliptical hole, a square hole, a slot hole, etc. to allow flow in the circumferential direction.
The spacer 15 and the stator wedge 12 may be integrated.

〔Effect of the invention〕

As described above, according to the present invention, in a liquid-cooled rotating electric machine, a radial duct formed by radially arranging spacers around the stator core is provided at one or more locations in the axial direction, and the stator wedge and the spacer are connected to each other. Since the inner periphery of all radial ducts between the two is filled with stuffing, the cooling effect of the stator core and stator windings of the stator is increased, and the temperature difference in the axial direction is particularly reduced. In addition, due to the filling, the increase in stirring loss due to the rotation of the rotor is small, and there is no sudden temperature rise of the cooling water due to increased stirring loss and the accompanying water boiling phenomenon, and insulation deterioration of the stator windings is prevented. This has the excellent effect of making it possible to obtain a highly reliable liquid-cooled rotating electric machine.

[Brief explanation of drawings]

Figure 1 is a vertical cross-sectional view showing a conventional liquid-cooled rotating electrical machine.
Figure 2 is a cross-sectional view taken along line A-A in Figure 1;
The figure is a longitudinal cross-sectional view showing one embodiment of the liquid-cooled rotating electric machine of the present invention, FIG. 4 is a cross-sectional view taken along line B-B in FIG. 3, and FIG. 5 is a cross-sectional view showing another embodiment. It is. DESCRIPTION OF SYMBOLS 1... Frame, 2... Stator, 3... Water gap, 4... Bearing, 5... Rotating shaft, 6... Rotor, 7... Pump, 10... Stator core, 11...
... Stator winding, 12 ... Stator wedge, 13 ... Gap, 14 ... Radial duct, 15 ... Spacer, 16 ... Filling.

Claims (1)

[Claims] 1 In a liquid-cooled rotating electric machine in which the coolant sealed inside the machine circulates through a water gap formed between the inside of the stator core and the outside of the rotor core in the axial direction and back outside, the stator core slot and the A gap is provided between the stator windings housed in the core slots, and radial ducts formed by radially arranging spacers in the stator core are provided at one or more locations in the axial direction. Between the stator wedge for holding the windings and the spacer, a stuffing that blocks the entire inner circumferential surface of the radial duct is fixed by the stator wedge, the stator winding, or the spacer, and the gap and the radial duct are A liquid-cooled rotating electric machine characterized in that a coolant passage passing through the water gap is provided independently of a coolant passage passing through the water gap.