JP2017038489A - Motor cooling device - Google Patents

Abstract

To provide a motor cooling device having a simple and compact structure and low cost.
A cooling device (1) is placed on an electric motor stator (11) and receives a heat collecting jacket (2) for receiving heat generated by the electric motor stator (11), and a heat pipe that forms a closed loop as a whole and contains refrigerant therein. 3. The heat pipe 3 is in contact with the heat collecting jacket 2 and is not in contact with the heat collecting jacket 2 and the heat pipe side 3b and the heat pipe bottom 3c that receive heat from the heat collecting jacket 2, and releases heat to the outside. And a heat pipe heat radiating part 3a. In the cooling device 1, the heat generated by the motor stator 11 due to the self-excited vibration of the refrigerant in the heat pipe 3 passes through the heat collecting jacket 2, the heat pipe side 3 b and the heat pipe bottom, and the heat pipe heat radiating part 3 a. To the outside.
[Selection] Figure 4

Description

  The present invention relates to an electric motor cooling device.

  Proper cooling of the motor during operation is important in terms of maintaining performance. Recently, for the cooling of the electric motor, the fins provided on the outside of the electric motor (casing), an electric motor mounted on the rotating shaft end impeller or another location of the blower is ventilated cooling air to dissipate method (former forced self The mainstream is the air cooling method, the latter being the forced other force air cooling method). In some electric motors, there are cases in which an internal ventilation cooling method is employed, such as providing air holes or grooves in the rotor or making slits in the stator at equal intervals.

  Recently, there is an increasing demand for a high-speed electric motor capable of rotating at a high speed of 10,000 rpm or more in addition to a small size and a high output. In such an electric motor, the forced self-winding cooling method is not sufficient for cooling, and because it rotates at high speed, it is difficult to ensure the strength and rigidity of the rotor. There are also cases where a method of cooling by ventilating (Patent Document 1) or a method of cooling by placing a water cooling jacket on the stator is employed. Recently, as shown in Patent Document 2, a method has been devised in which the stator has a split structure, and heat transfer fins in which heat pipes are embedded are provided in the split part to release the heat of the stator to the external refrigerant flow path part. Has been.

Japanese Patent No. 4864492 JP 2010-226918 A

  However, in the prior art for improving the cooling capacity of the high-speed motor, the structure of the stator becomes complicated, which affects the cost during processing and assembly, and the auxiliary pumps such as the cooling pump for the stator and the blower The installation space and the auxiliary drive power source may affect the miniaturization and power saving of the high-speed motor device.

  Then, this invention makes it a subject to provide a simple and compact structure and a low-cost electric motor cooling device.

  In order to solve the above-described problems, the present invention provides a heat collection jacket that covers a motor stator and receives heat generated by the motor stator, and a heat that forms a closed loop as a whole and contains a refrigerant therein. A heat pipe that is in contact with the heat collection jacket and receives heat from the heat collection jacket, and is not in contact with the heat collection jacket and releases heat to the outside. A heat pipe heat radiating section, and heat generated by the motor stator due to self-excited vibration of the refrigerant in the heat pipe is passed through the heat collecting jacket, the heat pipe heat receiving section, and the heat pipe heat radiating section. The motor cooling device is characterized by being discharged to the outside.

  ADVANTAGE OF THE INVENTION According to this invention, a simple and compact structure and a low-cost electric motor cooling device can be provided.

It is a figure which shows the principle of operation principle of the self-excited vibration heat pipe applied to this embodiment. It is a perspective view which shows the external appearance of a cooling device. It is a perspective view which shows the external appearance of a cooling device. It is a perspective view which shows the external appearance of an electric motor stator and the cooling device covered on it. It is sectional drawing at the time of cutting the cooling device etc. of FIG. 4 in the arrow A direction. It is sectional drawing at the time of cutting the cooling device etc. of FIG. 4 in the arrow B direction. It is an enlarged view of the area | region C in sectional drawing, such as a cooling device of FIG. It is a perspective view which shows the external appearance of the cooling device etc. containing the heat sink wind tunnel etc., (a) is a figure which shows the state which isolate | separated the heat sink wind tunnel, (b) shows the state which attached the heat sink wind tunnel. FIG. It is sectional drawing at the time of cutting the cooling device etc. of FIG.8 (b) in arrow D direction. It is sectional drawing at the time of cutting the cooling device etc. of FIG.8 (b) in the arrow E direction.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  First, an operation principle concept of a self-excited vibration heat pipe applied to the present embodiment will be described. As shown in FIG. 1, the heat pipe 101 forms a closed loop as a whole, and the refrigerant 103 that changes into the liquid phase 103a or the gas phase 103b depending on the temperature is enclosed inside, and deprives the heat receiving portion 102 that deprives heat from the object to be cooled. And a heat dissipating part 106 that dissipates heat. The refrigerant 103 that has received heat from the cooling target in the heat receiving unit 102 changes from the liquid phase 103 a to the gas phase 103 b in the evaporation unit 104, and then moves to the heat radiating unit 106 to flow outside the heat pipe 101. By dissipating heat to (atmosphere or the like), the condensation unit 105 changes from the gas phase 103b to the liquid phase 103a.

  Due to this phase change, the refrigerant 103 generates self-excited vibration between the heat receiving unit 102 and the heat radiating unit 106, and efficiently moves the heat absorbed by the heat receiving unit 102 to the heat radiating unit 106 without using an auxiliary device such as a pump or a compressor. It becomes possible.

  Here, the thermal conductivity of the heat pipe 101 is compared with the thermal conductivity of a typical substance. First, the thermal conductivity of the electrical steel sheet that is the material of the motor stator is 17 [W / (m · K)], the thermal conductivity of aluminum is 165 [W / (m · K)], and the thermal conductivity of copper is 400 [W / (m · K)]. On the other hand, the heat conductivity of the heat pipe 101 (the heat conductivity including the heat transfer action by the refrigerant) is 2000 [W / (m · K)]. Therefore, according to the heat pipe 101, a significantly greater heat transport performance can be expected compared to other cases, which can contribute to downsizing of the cooling device and the like.

  Next, the structure of the cooling device 1 (electric motor cooling device) of this embodiment will be described. As shown in FIGS. 2 and 3, the cooling device 1 is covered with a motor stator 11 (see FIG. 4) and receives a heat generated by the motor stator 11 and has a cylindrical heat collecting jacket 2 (the heat receiving jacket of FIG. 1). And a heat pipe 3 that forms a closed loop as a whole and accommodates a refrigerant therein.

  The heat pipe 3 comes into contact with the heat collecting jacket 2, the heat pipe side 3b (heat pipe heat receiving portion) for receiving heat from the heat collecting jacket 2, a heat pipe bottom 3c (heat pipe heat receiving unit), and the heat collection jacket 2 A heat pipe heat dissipating part 3a that is not in contact and emits heat to the outside. The heat pipe bottom 3c is disposed in parallel with the axial direction of the motor stator 11 at a position on the bottom side of the motor stator 11 when the motor is used.

  More specifically, in the cooling device 1 of the present embodiment, the heat pipe 3 is composed of two independent closed loops. Each closed loop includes a heat pipe side portion 3b that receives heat from the heat collecting jacket 2 and a heat pipe heat radiating portion 3a that conducts the heat to the outside, as shown in FIGS. Thus, the structure is such that the lower part of each end of the heat pipe side 3b is connected by the heat pipe bottom 3c.

  In the cooling device 1, the heat generated in the motor stator 11 due to the self-excited vibration of the refrigerant in the heat pipe 3 passes through the heat collection jacket 2, the heat pipe side 3 b and the heat pipe bottom 3 c, and the heat pipe heat radiating unit 3 a. And release to the outside.

  In addition, the circumference | surroundings (details are mentioned later) of the heat pipe thermal radiation part 3a are equivalent to the thermal radiation part 106 of FIG. As the material of the heat collecting jacket 2, a metal having high thermal conductivity such as an aluminum alloy is used.

  The cooling device 1 shown in FIG. 2 and FIG. 3 is used, for example, by putting two units on a conventional motor stator 11 as shown in FIG. The heat collecting jacket 2 may be fixed to the electric motor stator 11 by, for example, shrink fitting. 5 is a cross-sectional view of the cooling device 1 and the like of FIG. 4 taken along the direction A. FIG. 6 is a cross-sectional view of the cooling device 1 and the like shown in FIG. FIG. 7 is an enlarged view of a region C in the cross-sectional view of the cooling device and the like of FIG.

  In each of the two cooling devices 1, first, heat generated in the electric motor stator 11 is conducted to the heat collecting jacket 2. Next, the heat is conducted from the heat collecting jacket 2 to the heat pipe side 3b and the heat pipe bottom 3c. In order not to lower the heat transfer performance, it is necessary to closely contact (increase the contact area) between the heat collecting jacket 2 and the heat pipe side 3b. As a countermeasure against gaps due to such processing accuracy, in this embodiment, as shown in FIG. 7, the groove 2 a provided on the heat collecting jacket 2 side and having a size matching the diameter of the heat pipe 3. After the heat pipe side portion 3b is wound around, the gap formed in the groove 2a is filled with the heat conductive resin 4 (heat conductive material, which may be thermogrease or the like). Thereby, the heat of the heat collecting jacket 2 can be sufficiently conducted to the heat pipe side portion 3b. Since the heat pipe bottom 3c is much shorter than the entire length of the heat pipe side 3b, such a groove may not be provided on the heat collecting jacket 2 side, but may be provided.

  Here, the reason why the two cooling devices 1 are used is, for example, as follows. First, even if a failure occurs in one of the two cooling devices 1, it is possible to realize redundancy that the other can maintain heat dissipation performance. Moreover, since the length of the heat pipe 3 in each cooling device 1 can be reduced to about half as compared with the case of using one cooling device, the refrigerant moves while suppressing the pressure loss of the refrigerant moving through the heat pipe 3. It becomes easy. Moreover, it becomes easy to perform construction when the cooling device 1 is attached to the electric motor stator 11.

  Next, with reference to FIGS. 8 to 10, the structure of the cooling device 1 when a heat radiating portion wind tunnel 5 or the like is further added as a component of the cooling device 1 will be described. FIG. 8 is a perspective view showing the external appearance of such a cooling device 1 and the like. FIG. 8A is a view showing a state where the heat-dissipating part wind tunnel 5 is separated, and FIG. It is a figure which shows a state. FIG. 9 is a cross-sectional view of the cooling device 1 and the like shown in FIG. FIG. 10 is a cross-sectional view of the cooling device 1 and the like in FIG.

As shown in FIGS. 8 to 10, the cooling device 1 includes a heat radiating portion wind tunnel 5, a ventilation fan 6, and heat radiating fins 7 in addition to the heat collecting jacket 2 and the heat pipe 3.
The heat dissipating part wind tunnel 5 covers the heat pipe heat dissipating part 3 a and has openings on both end sides in the axial direction of the electric motor stator 11.

The ventilation fan 6 is attached to the heat radiating portion wind tunnel 5, takes air into the inside from the openings at both ends of the heat radiating portion wind tunnel 5, and discharges the taken air to the outside.
The heat radiating fins 7 are disposed in the heat radiating portion wind tunnel 5 and receive heat from the heat pipe heat radiating portion 3a and conduct it to the air.

  Next, attachment of each component will be described. The heat collecting jacket 2 is attached by shrink fitting or the like to the electric motor stator 11 in which a part of the electric motor rotor 14 is accommodated, and the electric motor casing 12 is further attached to the outside by shrink fitting or the like. The motor casing 12 is provided with a flat portion at the top, and a hole through which the heat pipe heat radiating portion 3a passes is provided in the flat portion. Thereby, the heat pipe heat radiation part 3a penetrates the said hole of the electric motor casing 12, and protrudes to the upper part. The bearing 13 is attached as shown in FIGS.

  A heat pipe radiator portion 3a which protrudes efficiently cooled (i.e., the heat radiation is allowed to) to condense inside the refrigerant, on the motor casing 12, fitted with a heat radiating portion for wind tunnel 5 fitted with ventilation fan 6 The heat of the heat pipe heat radiating portion 3a is removed in the heat radiating portion wind tunnel 5. Further, by providing the heat radiating fins 7, the heat of the heat pipe heat radiating portion 3a is conducted to the heat radiating fins 7, and the heat radiating fins 7 having a large surface area are in contact with the air in the heat radiating portion wind tunnel 5, thereby more efficiently. The heat pipe heat radiation part 3a can be cooled.

  As described above, the ventilation fan 6 releases the air in the heat radiating portion wind tunnel 5 to the outside. Thereby, air flows in the direction shown by the arrow in FIG. That is, air is taken in from the openings at both ends of the heat dissipating part wind tunnel 5, and the air warmed in the heat dissipating part wind tunnel 5 is discharged from the ventilation fan 6 to the outside. The reason for making the air flow direction in this way is that the coil end portion (both ends in the axial direction) generates the most heat in the motor stator 11, so that cold air is first applied to the coil end portion. This is to improve the cooling performance.

  As described above, according to the cooling device 1 of the present embodiment, the heat generated in the motor stator 11 due to the self-excited vibration of the refrigerant in the heat pipe 3 is converted into the heat collection jacket 2, the heat pipe heat receiving portion (on the heat pipe side). Part 3b, heat pipe bottom 3c) and heat pipe heat radiating part 3a can be discharged to the outside, so no auxiliary equipment such as a separate pump or blower for moving the refrigerant is required, and a simple and compact structure And the low-cost cooling device 1 is realizable.

  Moreover, since the cooling device 1 can be attached to the motor stator 11 having the conventional structure, it is possible to avoid the cost for processing the motor stator 11.

  Moreover, the heat transfer efficiency from the heat collecting jacket 2 to the heat pipe side portion 3b is increased by filling the gap between the groove 2a provided in the heat collecting jacket 2 and the heat pipe side portion 3b with the heat conductive resin 4. Can be improved.

  Moreover, by providing the heat radiating portion wind tunnel 5 including the ventilation fan 6, the heat pipe heat radiating portion 3a can be cooled more efficiently.

  Moreover, by providing the radiation fin 7, the heat pipe heat radiation part 3a can be cooled more efficiently.

  Further, as part of the portion of the heat pipe 3 that receives heat from the heat collecting jacket 2, heat that is arranged in parallel with the axial direction of the motor stator 11 at a position on the bottom side of the motor stator 11 when the motor is used. By providing the pipe bottom 3c, most of the refrigerant in the heat pipe 3 is accommodated in the heat pipe bottom 3c as a liquid phase when the electric motor is not used. Thereby, management and conveyance of the cooling device 1 become easier.

  In addition, as a refrigerant | coolant accommodated in the heat pipe 3, acetone, methanol, water etc. can be considered, for example, but considering the operating temperature of an electric motor, use environment temperature, the material of the heat pipe 3, etc., an appropriate refrigerant | coolant is considered. May be selected and used as appropriate.

This is the end of the description of the embodiments, but the aspects of the present invention are not limited to these.
For example, the external refrigerant that cools the heat pipe heat radiating unit 3a may be other gas (cooling gas or the like) or various liquids (water, oil, or the like) in addition to air.

The cooling device 1 of the present invention may be applied to a motor equipped with a magnetic bearing, and may be used for cooling not only the motor body but also the magnetic bearing.
In addition, about a concrete structure, it can change suitably in the range which does not deviate from the main point of this invention.

1 Cooling device (motor cooling device)
2 Heat collection jacket 2a Groove 3 Heat pipe 3a Heat pipe heat radiation part 3b Heat pipe side part (heat pipe heat receiving part)
3c Heat pipe bottom (heat pipe heat receiving part)
4 Thermal conductive resin (thermal conductive material)
DESCRIPTION OF SYMBOLS 5 Wind tunnel for heat radiating part 6 Ventilation fan 7 Radiation fin 11 Motor stator 12 Motor casing 13 Bearing 14 Motor rotor 101 Heat pipe 102 Heat receiving part 103 Refrigerant 103a Liquid phase 103b Gas phase 104 Evaporating part 105 Condensing part 106 Heat radiating part

Claims (5)

A heat collecting jacket that is placed on the motor stator and receives heat generated by the motor stator;
A heat pipe that forms a closed loop as a whole and contains a refrigerant inside,
The heat pipe is
A heat pipe heat receiving portion that contacts the heat collecting jacket and receives heat from the heat collecting jacket;
A heat pipe heat dissipating part that is not in contact with the heat collecting jacket and emits heat to the outside;
The heat generated by the motor stator due to the self-excited vibration of the refrigerant in the heat pipe is discharged to the outside through the heat collecting jacket, the heat pipe heat receiving part, and the heat pipe heat radiating part. Electric motor cooling device. The heat collecting jacket is provided with a groove for accommodating at least a part of the heat pipe heat receiving portion,
The electric motor cooling device according to claim 1, wherein a gap between the heat pipe heat receiving portion and the groove accommodated in the groove is filled with a heat conductive material. Covering the heat pipe heat radiating portion, and a wind tunnel for a heat radiating portion having openings on both end sides in the axial direction of the electric motor stator,
A ventilation fan that is attached to the heat radiating unit wind tunnel, takes air into the inside from an opening of the heat radiating unit wind tunnel, and discharges the taken air to the outside. Item 3. The electric motor cooling device according to Item 2. The electric motor cooling device according to claim 3, further comprising: a heat dissipating fin disposed in the heat dissipating part wind tunnel and receiving heat of the heat pipe heat dissipating part and conducting it to the air. The heat pipe heat receiving portion includes, as a part thereof, a heat pipe bottom portion arranged in parallel with the axial direction of the electric motor stator at a position on the bottom side of the electric motor stator when the electric motor is used. The electric motor cooling device according to any one of claims 1 to 4.

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