JPH0657069U - Rotating electric machine cooling device - Google Patents

Abstract

(57) [Summary] [Purpose] Even in high-speed rotating electric machines, the double-sided ventilation method is adopted to sufficiently enhance the cooling effect. A flow dividing chamber 13 is provided at the center of the frame 10 in the axial direction, and side bearing pipes 14a and 14b are provided in each bearing bracket 15 on the direct coupling side or the anti-direct coupling side.
5 is provided with a shield plate 16 as an air guide inside, and the cooling wind is introduced from the inside of the bearing bracket to the stator winding 12
b It is distributed inside.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a ventilation cooling device for a rotating electric machine, and more particularly to a ventilation passage for cooling the ventilation between a rotor and a stator equipped with another power blower in a high speed machine.

[0002]

[Prior art]

 In rotary electric machines such as induction motors, variable speed operation is performed by an inverter power supply, and there are cases where they are operated in a high-speed rotation range that has never existed before. In this case, in order to suppress the temperature rise due to mechanical loss such as electric loss and wind loss generated in the rotor, the air gap between the stator and the rotor is forcedly ventilated by an external blower, ， The rotor surface is actively cooled.

As a method of forcibly cooling the inside of the air gap with ventilation, as shown in FIG. 3, the frame 1 is fixed by providing a cooling air inlet 1a on the direct connection side and a cooling air outlet 1b on the opposite direct connection side. A one-sided ventilation system configured to blow air between the child 2 and the rotor 3 from the direct connection side to the anti-direct connection side, and the cooling air inlet 1a at the axial center of the frame 1 as shown in FIG. It is provided in communication with the iron core duct 2a, and cooling air outlets 1b are provided on the direct connection side and the anti-direct connection side of the frame 1, and air is blown from the outer peripheral portion of the stator frame to branch left and right into the air gap of the stator winding 2b. There is a double-sided ventilation system configured to exhaust air through the ends.

[0004]

[Problems to be solved by the device]

 In this way, the one-sided ventilation method or the two-sided ventilation method is cooled by forced air cooling, and the two-sided ventilation method has the advantage that the ventilation resistance is smaller and the temperature gradient in the axial direction is gentler than the one-sided ventilation method. However, when the rotating electrical machine is operated by a high frequency power supply that exceeds the commercial frequency (50/60 HZ) by an inverter power supply, etc., the carrier frequency of the inverter itself (usually several thousand HZ) and the basic high frequency influence the rotor surface. The eddy current loss increases, and further, in machines used in a high speed rotation range to some extent, the rotor core itself has a lump structure that is integral with the shaft, so the eddy current loss further increases. Therefore, in order to suppress the temperature rise due to such an increase in loss to a low level, even if the above-mentioned double-sided ventilation system is adopted, the ventilation passage is formed only in the air gap and the air volume is limited. However, it is still inadequate from the point of view of the increase in loss and the increase in temperature and the cooling, and the wind temperature at the time of reaching the end of the stator winding after passing through the air gap may rise to nearly 200 ° C. In some cases, the heat resistance limit of the insulator of the stator winding 2b was exceeded.

Another method is to provide a ventilation hole in the axial direction of the stator iron core to increase the overall ventilation amount, but because the ventilation resistance in the air gap is large, cooling on the rotor surface is not possible. May deteriorate, and as a result, the rotor may be heated.

The present invention aims to provide a cooling device for a rotating electric machine, which is designed to sufficiently cool the rotating electric machine.

[0007]

[Means for Solving the Problems]

 The present invention that achieves such an object is to provide a cooling air inlet at a central portion of a stator along an axial direction of a rotating electric machine, provide a duct for guiding the cooling air at the cooling air inlet to an air gap, and to provide the cooling air at both ends in the axial direction. It is characterized in that a side flow pipe is provided to circulate around the bracket, and a wind guide shield plate is provided so that the cooling air of the side flow pipe passes from the inside of the bracket through the inside of the bearing to the inside of the stator winding.

[0008]

[Action]

 The side flow piping reduces the ventilation resistance and increases the ventilation volume for effective cooling.In addition, the combination with the shield plate allows the cooling air to flow directly into the rotating electric machine without flowing through the bearing bracket and It can be applied to the end of the stator winding.

[0009]

【Example】

 An embodiment of the present invention will now be described with reference to FIG. In FIG. 1, a frame 10 is provided with a hollow water cooling jacket 11 through which cooling water flows in the circumferential direction. A stator core duct 12a is formed in the center of the stator core along the radial direction so as to divide the stator 12 mounted on the frame 10 into two parts in the axial direction. The cooling air outlet 10b is formed on the side opposite to the direct connection.

The cooling air inlet 13a is formed in the flow dividing chamber 13 provided outside the frame 10 so as to communicate with the stator core duct 12a. The flow dividing chamber 13 communicates with the stator core duct 12a at its center and also communicates with the side flow pipes 14a, 14b on the direct connection side and the anti-direct connection side at both axial ends.

The side flow pipes 14 a, 14 b have their inlets facing the flow dividing chamber 13, and their outlets communicate with the ventilation holes of the bearing bracket 15. Therefore, part of the cooling air in the flow dividing chamber 13 is guided to the inside of the bearing bracket 15 via the side flow pipes 14a and 14b.

Inside the bearing bracket 15, a shield plate 16 which is a wind guide is provided apart from the passage of the cooling air, and the shield plate 16 has a structure that has passed through the side flow pipes 14a and 14b. Cooling air is guided along the inside of the bearing bracket 15 to the inside of the bearing 17 and blown out inside the stator winding 12b. Therefore, the shield plate 16 is formed as a flat plate (lid-like plate) having a hole in the center of which the shaft is loosely fitted. Then, the cooling air guided by the shield plate 16 merges with the cooling air that has passed through the stator core duct 12a and the air gap between the rotor 18 and the stator 12 inside the stator winding 12b. Then, it will be blown out from the cooling air outlet 10b.

In the double-sided ventilation system having such a structure, a part of the cooling air supplied from the blower to the flow dividing chamber 13 passes through the stator core duct 12a and passes through the air gap to obtain a high cooling air temperature. In order to prevent the end of the stator winding 12b from being heated and the overall stator winding temperature rising, the cooling air of the side flow pipes 14a, 14b is applied to the bearing bracket between the shield plate 16. The air is blown onto the feed stator winding 12b, and the overall air temperature can be lowered and the air volume can be increased by mixing the cooling air. As a result, the temperature rise can be suppressed. Also, by providing the ventilation passages for the side flow pipes 14a and 14b, the total air volume can be increased as compared with the case where only the air gap is ventilated (see Fig. 4), but the loss resistance during ventilation in the air gap is about 8 Kpa. In terms of the characteristics of the blower used (operating pressure is about 7.5 Kpa), the required air volume can be obtained without changing the capacity.

FIG. 2 shows the air pressure and air volume characteristics (PQ characteristics) of a general blower. When the side flow pipes 14a and 14b are provided, the resistance of the entire ventilation passage is reduced, so that there is no side flow. As a result, the operating point will move in the direction of increasing the air flow, and it will be possible to cope without changing the blower capacity.

[0015]

[Effect of device]

 As described above, according to the present invention, the following effects can be obtained even if the blower capacity is the same by combining the side flow pipes and the shield plates in the both-side ventilation system. It is possible to increase the ventilation volume and reduce the temperature rise of the entire machine. In particular, by directly applying cold air from the blower to the end of the stator winding, it is possible to suppress the temperature rise of the winding due to the hot cooling air that has passed through the air gap. Since the cooling from the blower is directly supplied between the bearing bracket and the shield plate, the effect of heat from the stator and rotor does not reach the bearing, resulting in a heat insulating effect.

[Brief description of drawings]

FIG. 1 is a semi-mounted sectional view of an embodiment of the present invention.

FIG. 2 is a characteristic diagram of a cooling blower.

FIG. 3 is a configuration diagram of a one-sided ventilation system.

FIG. 4 is a configuration diagram of a both-side ventilation system.

[Explanation of symbols]

 10 Frame 10b Cooling Air Outlet 12 Stator 12b Stator Winding 13 Dividing Chamber 13a Cooling Air Inlet 14a, 14b Side Flow Piping 15 Bearing Bracket 16 Shield Plate 18 Rotor

Claims (1)

[Scope of utility model registration request] 1. A cooling air inlet is provided at a central portion of a stator along an axial direction of a rotating electric machine, a duct for guiding the cooling air from the cooling air inlet to an air gap is provided, and the cooling air is introduced around brackets at both ends in the axial direction. A cooling device for a rotating electric machine, characterized in that a side flow pipe is provided, and a wind guide shield plate is provided so that the cooling air of the side flow pipe passes from the inside of the bracket to the inside of the bearing to the inside of the stator winding.