JPH08275474A - Induction motor - Google Patents

Abstract

PURPOSE: To improve the self-cooling function of an induction motor and reduce the size of the entire motor by forming in end rings and shrink rings, placed at both the ends of a rotor, ventilation guides through the rings in the radial direction of the rotor of the motor. CONSTITUTION: Ventilation guides 13 are provided through shrink rings 11 and end rings 12 installed on rotor bars 10, and they penetrate the rings 11, 12 in the radial direction of a rotor shaft 4. Thus, receiving the centrifugal force due to the rotation of the rotor, a current of cooling air is produced in such a direction that cooling air in the ventilation guides flows in the radial direction of the rotor shaft 4. Part of cooling air introduced from the outside is returned to the ventilation guides 13 on the cooling air inlet 8 side; and part of cooling air that passed the ventilators 15 of a rotor core 3 is returned to the guides 13 on the cooling air outlet side. Thus, heat generated in the rotor and transferred to the shrink rings 11 and end rings 13 through the rotor bars 10, is effectively removed by heat exchange with cooling air. This enables the reduction of size of the entire motor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an induction motor with improved cooling performance, and more particularly to a squirrel cage induction motor for vehicles.

[0002]

2. Description of the Related Art FIG.
It is sectional drawing which shows the structure of the conventional squirrel cage induction motor described in the 6th publication. In the figure, 1 is a casing for accommodating the induction motor body, 2 is a stator core fixed to this casing, 2a is a stator coil inserted in this stator core, 3 is a rotor core, and this rotor is The iron core and the stator iron core are formed by stacking silicon steel sheets formed in a predetermined shape. 4 is a rotor shaft integrally fixing the rotor core, 5 is a bearing that rotatably supports the rotor shaft on the casing 1, 8 is a cooling air inlet for taking in cooling air blown from a blower (not shown), Reference numeral 9 is a cooling air outlet that is introduced from this cooling air inlet and discharges the cooling air that has undergone heat exchange inside the induction motor body to the outside, 11 is a shrink ring, and 12 is an end ring that short-circuits the conductor inserted in the rotor core , 15 are ventilation holes penetrating the rotor core 3.

Next, the operation will be described. In general, an induction motor for a vehicle is housed in a casing 1 in order to protect the induction motor main body from rain, dust, rocks when the vehicle is traveling, and the like. Therefore, in order to cool the induction motor main body efficiently, cooling air is blown into the casing 1 by the blower to forcibly cool the inside of the induction motor. That is, the cooling air blown from the blower is introduced from the cooling air inlet 8, passes through the ventilation hole 15 and is discharged to the outside from the cooling air outlet 9 as shown by the arrow in FIG. As a result, the cooling air exchanges heat with the stator coil 2a, the end rings 12, and the rotor core 3 while the cooling air passes through the induction motor, thereby cooling the entire induction motor.

[0004]

The conventional induction motor has the following problems.
Since the cooling air inlet 8 and the cooling air exhaust port 9 are arranged so as to be partitioned by the stator core 2 and the rotor core 3, the ventilation holes 15 are provided in the rotor core 3 so that the cooling air flows inside the induction motor. However, as shown in the characteristic diagram of FIG. 23, the stator coil 2a, the shrink ring 11 and the end ring 12 located on the cooling air exhaust port 9 side a are located on the cooling air inlet 8 side b. Since the cooling efficiency is lower than that of the stator coil 2a, the shrink ring 11 and the end ring 12 which are located, the heat generation temperature becomes high. Therefore, when designing the induction motor, the cooling air exhaust port 9 with a high heat generation temperature is used.
Since the heat generation temperature on the side is used as a reference, it is necessary to secure a large cooling space on the side of the cooling air outlet 9 corresponding to the heat generation temperature, which causes a problem that the entire apparatus becomes large. Note that FIG.
In FIG. 3, the vertical axis is the heat generation temperature, and the horizontal axis is the measurement point in the axial direction of the induction motor.

The present invention has been made to solve the above problems, and an object thereof is to improve the cooling effect of the induction motor and to downsize the entire apparatus.

[0006]

In the cooling structure for an induction motor according to the present invention, the end rings and the shrink rings provided at both ends of the rotor are provided with through ventilation guides penetrating in the radial direction of the rotor. .

Another cooling structure for an induction motor according to the present invention is one in which a rotor iron core is formed by alternately stacking silicon steel sheets having large ventilation hole diameters and silicon steel sheets having small ventilation hole diameters. Is.

Another cooling structure for an induction motor according to the present invention is one in which a ventilation hole is formed by spirally penetrating a rotor core.

Another cooling structure of the induction motor according to the present invention is such that the rotor core is provided with ventilation holes, which rotate in a spiral direction and whose rotational directions are opposite to each other.

Another cooling structure for an induction motor according to the present invention is one in which a ventilation hole is formed by spirally penetrating a rotor core and the blowing direction of a blower can be switched.

Another cooling structure of the induction motor according to the present invention is such that the diameter of the ventilation hole is gradually increased from the cooling air inlet side toward the cooling air discharge side.

Another cooling structure of the induction motor according to the present invention is such that the ventilation hole diameter, the rotor core outer diameter, and the stator core inner diameter gradually increase from the cooling air inlet side toward the cooling air outlet side. It is the one.

Another cooling structure of the induction motor according to the present invention is such that an alarm is issued when the differential pressure across the blower filter exceeds a predetermined value.

Another cooling structure for an induction motor according to the present invention is that an air passage is formed along the outer periphery of a casing to which a stator core is fixed and a part of the cooling air introduced from a cooling air inlet is passed through the air passage. It is designed to be divided into two.

Another cooling structure for an induction motor according to the present invention is one in which the ventilation passage is formed by a cylindrical member which is arranged concentrically with the casing.

In another cooling structure for an induction motor according to the present invention, a plurality of ventilation passages are formed by members having a substantially U-shaped cross section that are fixed to each other in the circumferential direction of the outer peripheral surface of the casing at a predetermined interval.

Another cooling structure for an induction motor according to the present invention is a cooling airflow that is diverted to the ventilation passage so that the ratio of the cooling airflow side airflow rate to the cooling air discharge side airflow rate becomes a predetermined value. Is adjusted.

Another cooling structure of the induction motor according to the present invention is such that a plurality of heat pipes are embedded in the stator core and one end of each heat pipe is exposed in the ventilation passage.

Another cooling structure for an induction motor according to the present invention is one in which a plurality of heat pipes are embedded in a rotor core and one end of each heat pipe is exposed in a ventilation hole.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1. Embodiment 1 of the present invention will be described below with reference to FIG. 1 is a sectional view of an induction motor showing a first embodiment of the present invention. In the figure, 1 is a casing for accommodating the induction motor body, 2 is a stator core fixed to this casing, 2a is a stator coil inserted in this stator core, 3 is a rotor core, and this rotor is The iron core and the stator iron core are formed by stacking silicon steel sheets formed in a predetermined shape. Reference numeral 4 denotes a rotor shaft integrally fixing the rotor core, 5 denotes a bearing for rotatably supporting the rotor shaft on the casing 1, 8 denotes a cooling air inlet for taking in cooling air blown from a blower (not shown),
10 is a rotor bar attached to the rotor, 11 is a shrink ring, 12 is an end ring that short-circuits the conductor inserted in the rotor core, 13 is the shrink ring 11 and the end ring 12 that penetrate in the radial direction of the rotor shaft 4. The plurality of through-ventilation guides are provided in the circumferential direction of the shrink ring 11 and the end ring 12. Reference numeral 14 is a clamper provided at the end of the rotor core 3, and 15 is a ventilation hole penetrating the rotor core 3 in the axial direction.

Next, the operation will be described. Rotor bar 1
The shrink ring 11 and the end ring 12 attached to 0 are provided with the through-ventilation guides 13 penetrating in the radial direction of the rotor shaft 4, so that when the induction motor is operated and the rotor rotates, the internal fan fan effect is provided. A flow of cooling air is generated as shown by arrow B in FIG. That is, since the cooling air introduced from the cooling air inlet 8 has a large pressure loss in the vicinity of the clamper 14, a part thereof goes in the opposite direction. Further, the cooling air in the through-ventilation guide 13 is ejected in the radial direction of the rotor shaft 4 as indicated by arrow B due to the centrifugal force generated by the rotation. As a result, a flow of cooling air as shown by the arrow B is generated, and the shrink ring 11 and the end ring 12 are effectively cooled to suppress the temperature rise. In FIG. 1, the through-ventilation guide 13 is connected to the shrink ring 11 on the cooling air inlet 8 side.
And the end ring 12 are also provided on the shrink ring 11 and the end ring 12 on the side of the cooling air outlet 9, and the cooling air that has passed through the ventilation holes 15 passes through the ventilation guide 13 on the side of the cooling air outlet 9. Passing through the cooling air outlet 9
The side shrink ring 11 and the end ring 12 are effectively cooled to suppress the temperature rise. Therefore, the heat generated in the rotor is conducted through the rotor bar 10, moves to the shrink ring 11 and the end ring 12 that are cooled by heat exchange with the cooling air, and is cooled.

Embodiment 2. 2 is a sectional view of an induction motor showing a cooling structure according to Embodiment 2 of the present invention, and FIG.
FIG. 7 is a plan view showing an example of a silicon steel plate used for rotor core 3 of the second embodiment. In the figure, a rotor core 3 formed by stacking silicon steel plates is shown in FIGS.
As shown in FIG. 1, silicon steel plates 17 and 18 having two types of shapes are used. Ventilation hole 1 of silicon steel plate 17
5 diameter D1 is formed smaller than ventilation hole 15 diameter D2 of silicon steel plate 18 (D1 <D2), and in the state laminated | stacked on rotor core 3, as shown in FIG. And 18 are stacked alternately. The diameter of the ventilation holes 15 of the silicon steel plates 17 and 18 is an induction motor of 350 KW, and when the rotor diameter is 240 mm, D1 = 18 mm,
D2 = about 26 mm. Next, the operation will be described. By alternately stacking the silicon steel plates 17 and the silicon steel plates 18 shown in FIG. 3 in the axial direction of the rotor shaft 4, the ventilation holes 15 as shown in FIG. 2 are formed in the rotor core. It is considered appropriate to set the ventilation hole D1 at 80% of the average ventilation hole diameter (D1 + D2) / 2 in order to secure the flow rate of the cooling air passing through the ventilation hole 15. By forming the ventilation holes 15 in this manner, the flow rate of the cooling air passing through the ventilation holes is maintained substantially constant, and the surface area of the ventilation holes 15 in contact with the cooling air is increased. Therefore, the cooling efficiency of the rotor core 3 is improved. It should be noted that the pressure loss of the cooling air becomes smaller when the silicon steel plates 17 and 18 are laminated alternately every few sheets than when the silicon steel sheets 17 and 18 are laminated one by one, and the cooling air easily flows through the ventilation holes 15 to enhance the cooling effect. . However, if the number of laminated sheets of the same silicon steel sheet is increased too much, the surface area in contact with the cooling air becomes small and the cooling effect is lowered. Therefore, it is considered appropriate to alternately stack the silicon steel sheets 17 and 18 every five sheets.

Embodiment 3. 4 is a perspective view showing a rotor of an induction motor according to a third embodiment of the present invention, and FIG. 5 is a plan view showing silicon steel plates laminated at positions C, D and E of FIG. Ventilation hole 15 in the third embodiment is formed in a spiral shape in the rotor core as shown by a broken line in FIG. Figure 5
(A), (B), and (C) are silicon steel plates 19, 20, and 21 at each cross-sectional position of C, D, and E of FIG. 4, showing that the ventilation hole positions are shifted in a spiral shape. There is. Next, the operation will be described. Ventilation hole 1 formed in rotor core 3
5 is formed in a spiral shape with its hole center at a constant distance from the center of the rotor shaft 4. The spiral ventilation hole 15 has a spiral direction that is the same as the rotation direction G of the rotor from the cooling air inlet 8 side toward the cooling air exhaust port 9 side. For this reason, the cooling air that has flowed into the ventilation holes 15 receives a force in the rotational direction of the rotor, so that the fluid resistance decreases, the flow rate of the cooling air that passes through the ventilation holes 15 increases, and the cooling effect increases. In addition, since the ventilation hole 15 is formed in a spiral shape, its overall length can be increased and the heat transfer area in contact with the cooling air can be increased, so that heat dissipation from the rotor core 3 is promoted and the cooling effect can be improved. Can be improved.

Fourth Embodiment 6 is a perspective view showing a rotor of an induction motor according to a fourth embodiment of the present invention, and FIG. 7 is a plan view showing silicon steel plates laminated at positions H, I and J of FIG. As shown in FIG. 6, the ventilation holes according to the fourth embodiment include an inner ventilation hole 22 formed in a spiral shape and an outer ventilation hole 23 formed in a spiral shape opposite to the inner ventilation hole 22. . 7 (A), (B), and (C) are silicon steel plates 24, 2 at respective cross-sectional positions of H, I, and J of FIG.
5 and 26, showing that the inner and outer ventilation holes 22 and 23 are formed in spirals in the opposite directions.

Next, the operation will be described. Rotor core 3
The ventilation holes formed on the inside are the ventilation holes 22 and 23 of two steps inside and outside.
And each diameter is the same. The inner ventilation hole 22 is formed in a spiral shape in the counterclockwise direction (L direction) with respect to the center of the rotor shaft 4 with a constant distance from the center of the rotor shaft 4 at the center of the hole. Further, the outer ventilation hole 23 is formed in a spiral shape in the clockwise direction (M direction) with respect to the center of the rotor shaft 4 with a constant distance from the center of the rotor shaft 4 at the center of the hole. According to such a configuration, when the rotation direction of the rotor is the M direction, the cooling air flowing into the outer ventilation holes 23 receives a force in the M direction in which the rotor rotates, so that the fluid passing through the outer ventilation holes 23 The resistance becomes small, and the cooling air easily flows in the N direction. On the other hand, when the rotation direction of the rotor is the L direction, the inner ventilation holes 22
Since the cooling air that has flowed in is subjected to a force in the L direction in which the rotor rotates, the fluid resistance passing through the inner ventilation holes 22 is reduced, and the cooling air easily flows in the 0 direction. Since the rotor core 3 is formed by laminating silicon steel plates in the axial direction, the thermal conductivity in the radial direction is more efficient than the thermal conductivity in the axial direction, and the temperature difference between the inner and outer circumferences is small. Therefore, by configuring as shown in FIGS. 6 and 7, the cooling air can easily flow into either one of the ventilation holes regardless of the direction of rotation of the rotor. The cooling effect can be improved. Further, since the inner and outer ventilation holes 22 and 23 are formed in a spiral shape, the overall length thereof can be increased and the heat transfer area in contact with the cooling air can be increased, so that heat dissipation from the rotor core 3 is promoted. Therefore, the cooling effect can be improved.

Embodiment 5. 8 is a sectional view showing a fifth embodiment of the present invention. In the figure, 15 is a ventilation hole formed in a spiral shape in the rotor core 3 as in the third embodiment, 6a and 6b are blowers driven by electric motors 7a and 7b, and the blowers of the blowers 6a and 6b are blown. The cooling air passing through the ventilation holes 15 is in the opposite direction. 28 is a rotation direction detector for detecting the rotation direction of the rotating shaft 4, 39 is a cooling air discharge port for discharging the cooling air in the P direction by the blower 6a, and 40 is for discharging cooling air in the Q direction by the blower 6b. Cooling air discharge ports, 41 and 42 are partition plates provided so that the cooling air discharge ports 39 and 40 can be opened and closed, respectively.
7 selectively operates both electric motors 7a and 7b based on the rotation direction of the rotary shaft 4 detected by the rotation direction detector 28. For example, when the electric motor 7a is operating, as shown in the drawing, It is a discrimination controller that controls to move the partition plate 41 to open the cooling air discharge port 39.

Next, the operation will be described. Embodiment 3
In this case, when the direction of the spirally formed ventilation hole 15 does not coincide with the rotation direction of the rotor, the fluid resistance of the cooling air passing through the ventilation hole 15 increases and the cooling effect decreases. In the fifth embodiment, the blowing direction of the cooling air is switched so that the spiral rotating direction of the cooling air passing through the spiral ventilation hole 15 and the rotating direction of the rotor coincide with each other. That is, the rotation direction detector 28 detects the direction in which the rotor shaft 4 rotates, and the detection signal is detected by the discrimination controller 27.
Output to. The determination controller 27 determines the rotation direction of the rotor shaft based on the detection signal of the rotation direction detector 28, and matches the rotation direction of the rotor shaft 4 with the spiral rotation direction of the cooling air passing through the ventilation holes 15. Thus, the electric motor 7a or 7b is selectively operated to drive either one of the blowers 6a or 6b. If the ventilation hole 15 of the rotor core 3 in FIG. 8 has a spiral rotation direction that is clockwise like the ventilation hole 15 in FIG. 4 and the rotation direction of the rotor is clockwise (direction G),
The discrimination controller 27 operates the electric motor 7a, moves the partition plate 41 as shown in the figure, opens the cooling air outlet 39, and blows the cooling air in the P direction from the blower 6a. As a result, the cooling air passing through the ventilation holes 15 passes through the spiral ventilation holes 15 in the clockwise direction in the same direction as the rotation direction of the rotor, and the cooling effect can be improved. On the other hand, if the rotation direction of the rotor is counterclockwise, the discrimination controller 27 operates the electric motor 7b and moves the partition plate 42 to open the cooling air exhaust port 40, and the partition plate 41 opens the cooling air exhaust port 30. After closing, the blower 6b blows cooling air in the Q direction. In this case, the cooling air passing through the ventilation holes 15 passes through the spiral ventilation holes 15 in the counterclockwise direction in the same direction as the rotation direction of the rotor, so that the cooling effect can be improved.

Sixth Embodiment 9 is a sectional view showing a sixth embodiment of the present invention. In the figure, 15 is a ventilation hole, which is formed to linearly penetrate through the rotor core 3, and the ventilation hole 15 is a hole on the cooling air outlet 9 side rather than a hole diameter on the cooling air inlet 8 side. It has a large diameter. That is, the diameter of the rotor core 3 is made constant in the axial direction, and the hole diameter of the ventilation hole 15 penetrating the rotor core 3 is gradually increased from the cooling air inlet side toward the cooling air discharge side to taper. It has a different structure. Therefore, the cooling air that has flowed into the ventilation hole 15 has the rotor core 3 for rotating the rotor inside the ventilation hole 15.
Since the centrifugal force is applied to and diffused in the radial direction, the fluid resistance in the ventilation holes 15 is reduced, the cooling air easily passes, and the cooling effect of the rotor core 3 can be improved. Moreover, since the area where the ventilation holes 15 contact the cooling air gradually increases in the direction in which the cooling air travels, the area for radiating the heat generated in the rotor core 3 increases on the cooling air outlet side, and the ventilation holes 15 The heat dissipation area increases as it approaches the exit. Further, since the inflowing cooling air hits the side surface of the rotor on the cooling air inlet side, the temperature generally rises larger on the cooling air outlet side than on the cooling air inlet side as shown in FIG. For this reason, if the cooling effect on the cooling air outlet side is increased as in the sixth embodiment, the temperature rise in the entire rotor can be made uniform and suppressed in the axial direction. Assuming that the ventilation hole diameter at the inlet of the ventilation hole 15 (the ventilation hole diameter of the clamper portion) is DI, the ventilation hole diameter at the ventilation hole outlet portion (the ventilation hole diameter of the spider portion) D0 is a structural constraint condition of the induction motor rotor. Therefore, 1.2 to 1.5 times (D0 = 1.2DI to 1.5DI) is considered to be ideal.

Embodiment 7. 10 is a sectional view showing Embodiment 7 of the present invention. In the figure, reference numeral 3 denotes a rotor core, which has a diameter on the cooling air inlet side which is smaller than that on the cooling air outlet side. Reference numeral 2 is a stator iron core, and the inner diameter thereof is tapered by making the diameter on the cooling air inlet side smaller than the diameter on the cooling air outlet side. Further, the gap 29 between the rotor core 3 and the stator core is set at a constant interval in the axial direction. Reference numeral 15 is a ventilation hole, and the rotor core 3
Is formed so as to linearly pass through and the ventilation hole 15
Has a larger hole diameter on the cooling air outlet 9 side than on the cooling air inlet 8 side. Next, the operation will be described. In the sixth embodiment, since the diameter of the ventilation hole 15 on the cooling air outlet side is large, the mechanical strength of that portion is weakened.
In the seventh embodiment, since the rotor core 3 is also tapered to have a larger diameter on the cooling air outlet side similarly to the taper provided to the ventilation hole 15, the mechanical strength does not decrease.
Further, the gap interval is set to be constant in the axial direction, the magnetic field from the stator coil to the rotor core 3 is made uniform in the axial direction, and the rotational force is made to approach the constant in the axial direction.

Embodiment 8. 11 is a sectional view showing an eighth embodiment of the present invention. In the figure, 30 is a static pressure point in the blower 6 filter, 31 is an atmospheric pressure measurement point, 32 is a differential pressure measuring device for measuring the differential pressure between the atmospheric pressure at the static pressure point in the filter and the atmospheric pressure at the atmospheric pressure measurement point, 33 reads the differential pressure from the output of this differential pressure measuring device,
A differential pressure value detector that outputs a certain value or more, an alarm sound generator 34 that issues an alarm by the output of the differential pressure value detector, and a blower filter 35 that adsorbs sand, dust, and the like of cooling air. Next, the operation will be described. The blower 6 for cooling the induction motor mounted on the train is attached to the lower floor of the train. Therefore, the blower filter 35 adsorbs sand dust and the like, and the blown amount of the blower 6 may be reduced, so that the induction motor may be burned. When the blower filter 35 of the blower 6 starts to be clogged, it becomes difficult for cooling air to pass through the blower filter 35, and the differential pressure across the blower filter 35 increases. Utilizing this, in the eighth embodiment, as shown in FIG. 11, before and after the blower filter 35 of the blower 6 for cooling the induction motor, that is, the atmospheric pressure P0 measured from the atmospheric pressure measurement point 31 and the static pressure in the filter. Static pressure PF measured from measurement point 30
The differential pressure measuring device 32 for measuring the differential pressure PF0 (= PF-P0) is attached, and the electric signal from the differential pressure measuring device 32 is read by the differential pressure value detector 33. The differential pressure value detector 33 compares the preset value Pr input in advance with the differential pressure PF0 input from the differential pressure measuring device 32, and when the differential pressure PFP becomes equal to or higher than the preset value Pr, activates the alarm sound generator 34. , Generate an alarm sound.

For example, with a blower of 15 kW, the rated point static pressure P (the blower outlet 36 of the blower outlet 36 shown in FIG. 12 is shown.
Static pressure-atmospheric pressure) and the air volume Q have the characteristic curves shown in FIG. 13, the air volume is 40 when the filter is not clogged.
(M ³ / min). When the filter is clogged and the air volume is reduced to 20 (m ³ / min), the rated point static pressure P is 16
It decreases by 0 (mmAq). Therefore, assuming that the differential pressure between the inside of the filter and the outlet of the blower hardly changes due to the change in the air volume, the differential pressure PF0 when the filter is not clogged (when the initial air volume is 40 (m ³ / min)) is 100.
(MmAq), the air volume is 50% of the initial air volume
Down (40 (m ³ / min) to 20 (m ³ / min)
Change to), the differential pressure PF0 becomes 260 (mmAq). Therefore, the specific set value Pr is 260 (mm
Aq) is an ideal value. From the above, it can be understood that the blower filter 35 is clogged by the alarm sound, and it will be necessary to replace the blower filter 35. Therefore, the blower filter 35 is replaced and the cooling efficiency of the induction motor is reduced to a predetermined value. Can be maintained above. In addition,
The number of ventilation holes in each of the above-described embodiments may be any number.

Ninth Embodiment 14 is a sectional view showing Embodiment 9 of the present invention, and FIG. 15 is a line XV- in FIG.
It is sectional drawing which shows the cross section along XV. In the figure, the same parts as those in the above-mentioned respective embodiments are designated by the same reference numerals, and the description thereof will be omitted. Reference numeral 43 denotes a tubular member which is disposed with a gap from the outer periphery of the casing 1 and has a length corresponding to the stator core, and 44 denotes an air passage formed between the tubular member 43 and the casing 1. The plate member 45 has four branch holes 46a, 46b, 46c, and 46d formed on the circumference on the inlet side. 47 is each of these branch holes 46a to 46
This is an air volume valve that regulates the amount of air that passes through d and flows into the ventilation passage 44.

Next, the operation will be described. First, the blower 6 is driven by the electric motor 7 to send out the cooling air A.
Then, the opening degree of the air flow valve 47 is adjusted, and the cooling air A is split into the cooling air B flowing to the stator core 2 and the rotor iron core 3 side and the cooling air C flowing to the ventilation passage 44 side as usual.
As a result, the stator core 2 whose temperature rises due to the heat generated from the stator coil 2a is cooled from the inside and outside by the cooling air B and the cooling air C, so that the cooling of the entire stator is promoted and the cooling effect is improved. Can be improved.

Embodiment 10. 16 is a sectional view showing Embodiment 10 of the present invention, and FIG. 17 is a line X in FIG.
It is sectional drawing which shows the cross section along VII-XVII. In the figure, the same parts as those in the above-mentioned respective embodiments are designated by the same reference numerals, and the description thereof will be omitted. 48a, 48b, 48c, 48d
Are substantially U-shaped members 49a, 49b, 49c, and 49d that are fixed to the outer periphery of the casing 1 at a predetermined interval.
Is an air passage formed between each of these members 48a to 48d and the casing 1, and branch holes 51a, 51b, 51c, 51d are formed by the plate member 50 on the inlet side. Reference numeral 52 is an air volume valve that adjusts the amount of air that passes through each of the branch holes 51a to 51d and flows into each of the air passages 49a to 49d.

Next, the operation will be described. First, the blower 6 is driven by the electric motor 7 to send out the cooling air A.
Then, the opening degree of the air volume valve 52 is adjusted, and the cooling air A is divided into the cooling air B flowing to the stator core 2 and the rotor core 3 side and the cooling air C flowing to the air passages 49a to 49d as usual. Shunted. As a result, the stator core 2 whose temperature rises due to the heat generated from the stator coil 2a is cooled from the inside and outside by the cooling air B and the respective cooling air C, so that the cooling of the entire stator is promoted and the ventilation passage is 49a each
Since it is divided into ~ 49d, the cooling air C flows evenly on the circumference of the stator core 2 without being biased, so that the cooling effect can be further improved.

Eleventh Embodiment 18 is a sectional view showing Embodiment 11 of the present invention. In the figure, the same parts as those in the above-mentioned respective embodiments are designated by the same reference numerals, and the description thereof will be omitted. Reference numeral 53 is a first air volume meter for measuring the air volume of the cooling air A from the blower 6, 54 is a second air volume meter disposed in the cooling air outlet 9 for measuring the air volume of the cooling air B, and 55 is the first air volume meter. And an air volume ratio calculator for calculating the air volume ratio of both air volumes measured by the second air volume meters 53, 54, and 56 is this air volume ratio calculator 5.
5 so that the air volume ratio calculated in 5 becomes constant.
It is an air volume valve control means for controlling and adjusting the air flow.

Next, the operation will be described. First, the air flow rate Q of the cooling air A sent from the blower 6 by the first air flow meter 53.
Measure _A. Next, the second air flow meter 54 measures the air flow rate Q _B of the cooling air B. Then, the air flow rate ratio calculator 55 calculates Q _B / Q _A from both air flow rates Q _A and Q _B thus measured.
= R is calculated, and the air flow valve control unit 56 controls and adjusts the air flow valve 47 so that the value becomes a predetermined value r ₀ set in advance. Since the value of Q _B / Q _A = r changes due to the influence of the temperature and humidity of the cooling air, the air flow valve control means 56
By controlling and adjusting the air volume valve 47 with
The air flow rate Q _C of the cooling air C flowing therein can be secured at a constant value, the cooling of the entire stator is promoted, and the cooling effect can be improved. Further, when the cooling efficiency of the entire induction motor is taken into consideration, r = 0.8 at Q _A = 20 to 40 (m ³ / min).
5 is considered an appropriate value.

Twelfth Embodiment FIG. 19 is a sectional view showing Embodiment 12 of the present invention. In the figure, the same parts as those in the above-mentioned respective embodiments are designated by the same reference numerals, and the description thereof will be omitted. 57 is a silicon steel plate forming the rotor core 3;
Is a heat pipe that is embedded in the silicon steel plate 57 and has one end protruding into the ventilation hole 15 by a predetermined length and exposed.
A large number of rotor cores 3 are arranged at predetermined intervals in the circumferential direction and the axial direction.

Next, the operation will be described. First, the cooling air A introduced from the cooling air inlet 8 is introduced into the ventilation hole 15, and one end of the heat pipe 58 embedded in the silicon steel plate 57 of the rotor core 3 is introduced into the ventilation hole 15. Since it is exposed, the heat generated by the rotor bar 10 and transferred to the silicon steel plate 57 by heat conduction is released by the heat pipe 58 into the cooling air A passing through the ventilation holes 15.
Cooling of the rotor as a whole is promoted and the cooling effect can be improved. Note that, for example, in a 350 KW induction motor, the rotor has a diameter of 240 mm, so the length L _{h of the} heat pipe is
It is considered that about 20 mm is appropriate, and the length of the protrusion into the ventilation hole 15 is preferably about L = 0.1 L _h , and further, the diameter is considered to be about 6 mm.

Thirteenth Embodiment 20 is a sectional view showing Embodiment 13 of the present invention, and FIG. 21 is a line X in FIG.
It is sectional drawing which shows the cross section along XI-XXI. In the figure, 59 is embedded in the stator core 2 and one end thereof is the casing 1.
A plurality of heat pipes penetrating through and exposed in the ventilation passage 44 by a predetermined length are arranged at predetermined intervals in the circumferential direction and the axial direction of the stator core 2.

Next, the operation will be described. First, a part of the cooling air A delivered by the blower 6 is branched by the air flow valve 47 and introduced into the ventilation passage 44 as the cooling air C, which is embedded in the stator core 2 in the ventilation passage 44. Since one end of the heat pipe 59 is exposed, the heat generated in the stator coil 2a and transferred to the inside of the stator core 2a by heat conduction is transferred to the cooling air C passing through the air passage 44 by the heat pipe 59. Since it is efficiently discharged, cooling of the entire stator core is promoted, and the cooling effect can be improved.

[0042]

As described above, according to the cooling structure for the induction motor of the present invention, the cooling air passes through the through-air guide provided through the end ring and the shrink ring by the inner fan effect. Since cooling is performed, cooling efficiency is improved, and the entire device can be downsized.

Further, according to another cooling structure of the induction motor of the present invention, since the rotor iron core is constructed by alternately laminating the silicon steel plates having large ventilation hole diameters and the silicon steel plates having small ventilation holes, the ventilation is performed. Since the heat transfer area of the hole is increased and the amount of heat released is increased, the cooling efficiency is improved and the size of the entire device can be reduced.

Further, according to another cooling structure of the induction motor of the present invention, since the cooling air passes through the spiral ventilation hole having less fluid resistance, the cooling air flow rate increases and the overall length of the ventilation hole becomes longer. Therefore, the cooling efficiency is improved and the entire apparatus can be downsized.

Further, according to another cooling structure of the induction motor of the present invention, the cooling air can pass through any of the spiral ventilation holes having a small fluid resistance to increase the cooling air flow rate. Further, since the entire length of the ventilation hole is increased, the cooling efficiency is improved and the size of the entire device can be reduced.

Further, according to another cooling structure of the induction motor of the present invention, the flow rate of the cooling air can be increased by appropriately changing the air blowing direction of the air blower so that the fluid resistance of the spiral ventilation hole becomes small. The cooling efficiency is improved, and the entire device can be downsized.

Further, according to another cooling structure of the induction motor of the present invention, the cooling air passes through the tapered ventilation holes to increase the cooling air flow rate, improve the cooling efficiency, and reduce the size of the entire apparatus. Can be converted.

Further, according to another cooling structure of the induction motor of the present invention, since the cooling air passes through the tapered ventilation holes, the cooling air flow rate is increased, the cooling efficiency is improved, and the entire apparatus is reduced in size. Can be converted. Further, the mechanical strength of the rotor core can be maintained.

Further, according to another cooling structure of the induction motor of the present invention, by warning the clogging of the filter, the cooling air of a predetermined amount or more can be always secured and the cooling efficiency can be maintained. Therefore, it is possible to reduce the size of the entire device.

According to another cooling structure of the induction motor of the present invention, a ventilation passage is formed along the outer periphery of the casing to which the stator core is fixed, and a part of the cooling wind introduced from the cooling wind inlet. By dividing the flow into the ventilation passage, it is possible to promote cooling of the entire stator and improve cooling efficiency.

Further, according to another cooling structure for an induction motor of the present invention, a cylindrical ventilation passage is formed concentrically with the casing along which the stator core is fixed and the cooling air inlet is provided. By diverting a part of the cooling air introduced from (1) to the air passage, the cooling of the entire stator can be promoted and the cooling efficiency can be improved.

Further, according to another cooling structure of the induction motor of the present invention, the stator core is arranged along the outer periphery of the casing to which the stator core is fixed, at a predetermined interval in the circumferential direction of the outer peripheral surface of the casing. By forming a ventilation path consisting of a member with a substantially U-shaped cross section and distributing a part of the cooling air introduced from the cooling air inlet to each ventilation path, the cooling of the entire stator is promoted and cooling efficiency is improved. Can be improved.

Further, according to another cooling structure of the induction motor of the present invention, the cooling is divided into the ventilation passage so that the ratio of the air volume on the cooling air inlet side to the air volume on the cooling air exhaust side becomes a predetermined value. By adjusting the air volume, the cooling of the entire stator can be further promoted and the cooling efficiency can be improved.

Further, according to another cooling structure of the induction motor of the present invention, a plurality of heat pipes are embedded in the stator core and one end of each heat pipe is exposed in the ventilation passage to thereby fix the stator. Cooling efficiency can be improved by promoting cooling as a whole.

Furthermore, according to another cooling structure of the induction motor of the present invention, a plurality of heat pipes are embedded in the rotor core, and one end of each heat pipe is exposed in the ventilation passage, whereby the rotor is cooled. Cooling efficiency can be improved by promoting cooling as a whole.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a cooling structure for an induction motor according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing a cooling structure for an induction motor according to a second embodiment of the present invention.

FIG. 3 is a plan view showing a silicon steel plate forming a rotor core according to a second embodiment of the present invention.

FIG. 4 is a perspective view showing a rotor core of an induction motor according to Embodiment 3 of the present invention.

FIG. 5 is a plan view showing a silicon steel sheet forming a rotor core according to a third embodiment of the present invention.

FIG. 6 is a perspective view showing a rotor core of an induction motor according to Embodiment 4 of the present invention.

FIG. 7 is a plan view showing a silicon steel plate forming a rotor core according to a fourth embodiment of the present invention.

FIG. 8 is a sectional view showing a cooling structure for an induction motor according to a fifth embodiment of the present invention.

FIG. 9 is a sectional view showing a cooling structure for an induction motor according to a sixth embodiment of the present invention.

FIG. 10 is a sectional view showing a cooling structure for an induction motor according to a seventh embodiment of the present invention.

FIG. 11 is a sectional view showing a cooling structure for an induction motor according to Embodiment 8 of the present invention.

FIG. 12 is a diagram showing a blower and a rated point static pressure according to the embodiment of the present invention.

FIG. 13 is a characteristic diagram showing the relationship between the rated pressure of the blower and the air flow rate of the blower.

FIG. 14 is a sectional view showing a cooling structure for an induction motor according to a ninth embodiment of the present invention.

15 is a cross-sectional view showing a cross section taken along line XV-XV in FIG.

FIG. 16 is a sectional view showing a cooling structure for an induction motor according to a tenth embodiment of the present invention.

FIG. 17 is a sectional view showing a section taken along line XVII-XVII in FIG. 16.

FIG. 18 is a sectional view showing a cooling structure for an induction motor according to an eleventh embodiment of the present invention.

FIG. 19 is a sectional view showing a cooling structure for an induction motor according to a twelfth embodiment of the present invention.

FIG. 20 is a sectional view showing a cooling structure for an induction motor according to a thirteenth embodiment of the present invention.

FIG. 21 is a sectional view showing a section taken along line XXI-XXI in FIG. 20.

FIG. 22 is a cross-sectional view showing a cooling structure for a conventional induction motor.

FIG. 23 is a characteristic diagram showing a temperature distribution in the rotor axial direction of a conventional induction motor.

[Explanation of symbols]

1 casing, 2 stator core, 3 rotor core, 4
Rotor shaft, 6 blower, 8 cooling air inlet, 9 cooling air outlet, 13 through ventilation guide, 15 ventilation hole, 43
Cylindrical member, 44, 49a, 49b, 49c, 49d Ventilation passage, 47, 52 Air flow valve, 45, 50 Plate material, 46
a, 46b, 46c, 46d, 51a, 51b, 51
c, 51d Branch hole, 48a, 48b, 48c, 48d
Member, 53 first air flow meter, 54 second air flow meter, 5
5 Air volume ratio calculator, 56 Air volume valve control means, 58, 59
heat pipe.

Claims (14)

[Claims] 1. A cooling structure is provided, in which cooling air introduced from a cooling air inlet by a blower is ventilated through ventilation holes formed through the rotor core in the axial direction of the rotor, and is exhausted to the outside from a cooling air outlet. In the induction motor, an end ring and a shrink ring, which are respectively provided at the cooling air inlet side end and the cooling air discharge port side end of the rotor, are provided with through ventilation guides penetrating in the radial direction of the rotor. . 2. A cooling structure in which cooling air introduced from a cooling air inlet by a blower is ventilated through a ventilation hole formed through the rotor core in the axial direction of the rotor and discharged from the cooling air outlet to the outside. In an induction motor, a rotor core is formed by alternately stacking a silicon steel sheet having a large ventilation hole diameter and a silicon steel sheet having a small ventilation hole diameter. 3. A cooling structure is provided in which cooling air introduced from a cooling air inlet by a blower is ventilated through ventilation holes formed through the rotor core in the axial direction of the rotor and discharged from the cooling air outlet to the outside. An induction motor, characterized in that a ventilation hole is formed by spirally penetrating a rotor core. 4. A cooling structure is provided in which cooling air introduced from a cooling air inlet by a blower is ventilated through ventilation holes formed through the rotor core in the axial direction of the rotor and discharged from the cooling air outlet to the outside. In the induction motor, a first ventilation hole formed by spirally penetrating the rotor core and a second ventilation hole formed by penetrating the rotor core in a spiral shape opposite to the first ventilation hole. An induction motor characterized by comprising: 5. A cooling structure is provided in which cooling air introduced from a cooling air inlet by a blower is ventilated through ventilation holes formed through the rotor core in the axial direction of the rotor and discharged from the cooling air outlet to the outside. An induction motor, comprising: a ventilation hole formed by spirally penetrating a rotor core; and means for switching a blowing direction of the blower. 6. A cooling structure is provided in which cooling air introduced from a cooling air inlet by a blower is ventilated through ventilation holes formed through the rotor core in the axial direction of the rotor and discharged from the cooling air outlet to the outside. In the induction motor, the diameter of the ventilation hole is gradually increased from the cooling air inlet side toward the cooling air discharge side, which is characterized in that. 7. A cooling structure is provided in which cooling air introduced from a cooling air inlet by a blower is ventilated through ventilation holes formed through the rotor core in the axial direction of the rotor and discharged from the cooling air outlet to the outside. In the induction motor, the ventilation hole diameter is gradually increased from the cooling air inlet side toward the cooling air outlet side, and the rotor core outer diameter is gradually increased from the cooling air inlet side toward the cooling air outlet side. In order to make the gap between the stator core and the rotor core uniform in the axial direction, the inner diameter of the stator core is gradually increased from the cooling air inlet side toward the cooling air discharge side. Induction motor. 8. A cooling structure is provided in which cooling air introduced from a cooling air inlet by a blower is ventilated through ventilation holes formed through the rotor core in the axial direction of the rotor and discharged from the cooling air outlet to the outside. An induction motor, comprising means for issuing an alarm when the differential pressure across the blower filter exceeds a predetermined value. 9. A cooling structure is provided in which cooling air introduced from a cooling air inlet by a blower is ventilated through ventilation holes formed through the rotor core in the axial direction of the rotor and discharged from the cooling air outlet to the outside. In the induction motor, a ventilation passage is formed along the outer periphery of the casing to which the stator core is fixed, and a part of the cooling air introduced from the cooling air inlet is diverted to the ventilation passage. Induction motor. 10. The induction motor according to claim 9, wherein the ventilation passage is formed by a tubular member arranged concentrically with the casing. 11. The induction motor according to claim 9, wherein a plurality of ventilation passages are formed by members having a substantially U-shaped cross section that are fixed to each other in the circumferential direction of the outer peripheral surface of the casing at a predetermined interval. 12. The air flow rate of the cooling air diverted to the ventilation passage is adjusted so that the ratio of the air flow rate on the cooling air flow inlet side to the air flow rate on the cooling air discharge side becomes a predetermined value. The induction motor according to claim 9. 13. The induction machine according to claim 9, wherein a plurality of heat pipes are embedded in the stator core and one end of each heat pipe is exposed in the ventilation passage. Electric motor. 14. A cooling structure is provided, in which cooling air introduced from a cooling air inlet by a blower is ventilated through ventilation holes formed through the rotor iron core in the axial direction of the rotor and discharged from the cooling air exhaust port to the outside. In the induction motor, a plurality of heat pipes are embedded in the rotor core, and one end of each heat pipe is exposed in the ventilation hole.