JP2009165294A - Totally enclosed fan-cooled motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that the flow speed of cooling gas drops to degrade cooling efficiency of a motor, since the flow speed vector of the gas exhausted from a cooling fan of a totally enclosed fan-cooled motor has a component in radial direction as well as the component in circumferential direction, the flow speed vector deflected in the direction along the surface of a frame by a fan cover also has the component parallel to a plate-like heat radiation fin as well as the component in vertical direction, and the component in vertical direction to the heat radiation fin of the flow speed vector interferes with the heat radiation fin to cause a significant pressure loss. <P>SOLUTION: The totally enclosed fan-cooled motor comprises a frame 3 that encloses a stator, a plurality of heatsinks 31 provided on the outer peripheral surface of the frame, a cooling fan 8 attached to the rotating shaft protruding outside the machine, and a fan cover 9 which deflects the airstream energized by the cooling fan to the direction along the outer peripheral surface. The heatsink has a pin shape. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention provides a fully-enclosed outer fan-shaped rotation in which an air flow generated by rotating a cooling fan attached to a rotating shaft protruding outside the rotating electric machine flows through a radiator provided on the outer peripheral surface of the rotating electric machine frame. It relates to electric machinery.

  As a conventional fully-enclosed fan-shaped rotating electrical machine, the fan-side end face of the cooling fin (heat radiating body) in the stator frame is inclined so that the fin length becomes a short side from the upper side of the cooling fin toward the base side. By forming, it is configured to deflect the cooling gas blown by the fan toward the base side of the cooling fin, thereby heat exchange between the cooling gas and the cooling fin along the gap between the cooling fins of the stator frame There is one that can improve the efficiency and suppress the temperature rise inside the rotating electrical machine main body (see, for example, Patent Document 1).

Japanese Patent No. 3253709 (page 3, FIG. 1)

  In the conventional fully-enclosed fan-shaped rotating electrical machine configured as described above, the shape of the heat radiating body is a plate shape, and the heat radiating body is provided on the frame so as to be parallel to the rotation axis. Therefore, the cooling gas flowing into the fan cover from the intake port as the cooling fan rotates is pressurized by the cooling fan and discharged in the in-plane direction substantially perpendicular to the rotation axis, but is discharged from the cooling fan. The flow velocity vector of the cooling gas has a radial component and a circumferential component, and the flow velocity vector after being deflected in the direction along the surface of the frame by the fan cover is also perpendicular to the component parallel to the plate-shaped radiator. Has a directional component. The component of the flow velocity vector in the direction perpendicular to the heat dissipator interferes with the heat dissipator and causes a large pressure loss. For this reason, there existed a subject that the flow velocity of cooling gas fell and the cooling efficiency of a rotary electric machine fell.

  The present invention has been made to solve the above-described problems of the prior art, and an object thereof is to provide a fully enclosed outer fan-shaped rotating electrical machine in which the cooling efficiency by the cooling fan is improved.

  A rotating electrical machine according to the present invention includes a frame surrounding a stator, a plurality of heat radiators provided on an outer peripheral surface of the frame, a cooling fan attached to a rotating shaft protruding outside the machine, and the cooling A fully-enclosed fan-shaped rotating electrical machine having a fan cover for deflecting an airflow energized by a fan in a direction along the outer peripheral surface of the frame, wherein the radiator is formed in a pin shape. is there.

  In this invention, since the plurality of heat dissipating bodies provided on the outer peripheral surface of the frame are formed in a pin shape, the air flow urged by the cooling fan flows in the direction along the flow velocity vector. The interference between the gas and the heat radiating body is reduced, and the pressure loss when the cooling gas passes between the heat radiating bodies is reduced. Thereby, the flow velocity of the cooling gas is increased, heat exchange between the cooling gas and the heat radiating body is promoted, and the rotating electrical machine can be effectively cooled.

Embodiment 1 FIG.
1 to 5 are views for explaining a fully-enclosed external fan motor (hereinafter simply abbreviated as an electric motor) as an example of a fully-enclosed external fan-shaped rotating electrical machine according to Embodiment 1 of the present invention, and FIG. FIG. 2 is a plan view conceptually showing the external appearance when the fan cover shown in FIG. 1 is removed, FIG. 3 is a front view showing the fan cover shown in FIG. 1, and FIG. FIG. 5 is a characteristic diagram showing the temperature rise of the frame measured for the embodiment of the electric motor shown in FIG. 1 in comparison with a conventional electric motor (comparative example). In the figure, an electric motor 1 includes a cylindrical stator 2, a frame 3 that fixes the stator 2 and surrounds the stator 2, and a plurality of pin-shaped radiators that are erected on the outer peripheral surface of the frame 3. 31, a rotor 4 provided so as to have a predetermined gap with respect to the inner peripheral surface of the stator 2, a rotating shaft 5 provided through the rotation center of the rotor 4 and fixed to the rotor 4, a load Load side bracket 7A for supporting the rotating shaft 5 protruding to the side (right side in FIG. 1) via a bearing 6A, anti-load side bracket 7B for supporting the rotating shaft 5 protruding to the opposite load side via a bearing 6B, A cooling fan 8 fixed to the rotating shaft 5 protruding to the load side, and a fan cover 9 for deflecting the airflow urged by the cooling fan 8 in a direction along the outer peripheral surface of the frame 3 are provided.

  The stator 2 includes an iron core 21 stacked in the rotation axis direction (left-right direction in FIG. 1) and a stator winding 22 wound in a plurality of grooves (not shown) formed in the iron core 21. The frame 3, the load side bracket 7 </ b> A, and the anti-load side bracket 7 </ b> B partition the inside and outside of the machine body, and the load-side bracket 7 </ b> A and the anti-load side bracket 7 </ b> B form an end face in the axial direction of the electric motor 1. Both ends of the rotating shaft 5 rotatably supported by the bearings 6A and 6B protrude from the machine, and the cooling fan 8 is fixed to a part of the anti-load side bracket 7B protruding to the outside of the machine. A load (not shown) is connected to a portion of the rotating shaft 5 that protrudes outside the load side bracket 7A. As the cooling fan 8, a radial fan is employed in order to exert the same air blowing performance regardless of the rotation direction of the electric motor 1, and a plurality of blades 81 are attached to the rotating shaft 5 as shown in FIG. 4. They are arranged radially.

  The fan cover 9 covers the cooling fan 8 and extends in the downstream direction of the air flow so as to surround substantially the entire pin-shaped radiator 31, and provides a cooling gas flow path in a space between the outer surface of the frame 3. A honeycomb-shaped intake port 9a for introducing cooling gas from the outside to the cooling fan 8 is provided on the end surface on the side opposite to the load, and the heat taken from the radiator 31 is discharged along with the airflow on the end surface on the load side. An exhaust port 9b is formed. The fan cover 9 is fixed to the frame 3 by fixing means (not shown). Since other configurations are the same as those of the conventional fully-enclosed fan motor, the description thereof is omitted.

The characteristic part of this Embodiment 1 is
1. The frame 3 is manufactured by a manufacturing method in which a desired shape can be formed relatively freely, such as aluminum die casting, for example, and the radiator 31 formed on the outer peripheral surface thereof has a cylindrical pin shape. In addition, the shape of the heat radiator 31 is not limited to a cylindrical shape, and may be other shapes such as an elliptical column shape and a square column shape as long as the shape is a pin shape.
2. As shown in FIG. 2, the pin-shaped heat radiator 31 is arranged substantially parallel to V <b> 2 so as to follow the flow velocity vector V <b> 2 of the cooling gas flowing on the outer surface of the frame 3.
3. As shown in FIG. 1, the fan cover 9 is formed in a duct shape so as to extend to the vicinity of the load side end surface portion so as to cover all the radiators 31 formed on the frame 3.
4). The inlet 9a of the fan cover 9 has a honeycomb shape as shown in FIG.

  Next, the operation of the first embodiment configured as described above will be described. When the electric motor 1 is driven, the cooling fan 8 also rotates through the rotating shaft 5, and the cooling gas flows into the fan cover 9 from the air inlet 9 a of the fan cover 9. At this time, since the shape of the through-holes constituting the intake port 9a is a honeycomb shape, it is possible to increase the aperture ratio and the open area as compared with the other hole shapes, and the cooling gas passes through the intake port 9a. The pressure loss when passing is reduced, and the flow rate of the cooling gas flowing into the fan cover 9 is increased. Furthermore, since it has a honeycomb shape, a relatively high strength can be maintained even if the opening area is large, and at the same time, there is an advantage that less material is required for manufacturing by molding or the like if the outer diameter is the same. The cooling gas flowing into the fan cover 9 is urged by the cooling fan 8 in an in-plane direction substantially perpendicular to the rotation shaft 5. As shown in FIG. 4, the flow velocity vector V1 of the cooling gas discharged from the cooling fan 8 at this time has a radial component Vr and a circumferential component Vω.

2 and 4, when the outer diameter of the cooling fan 8 is D, the width of the blade 81 is E, the angular velocity is ω, and the design value of the air volume is Q, the radial component Vr of the flow velocity vector V1 is The components Vω in the circumferential direction are as shown in the following formulas 1 and 2, respectively.
Vr = Q / (πDE) (Equation 1)
Vω = ωD / 2 (Formula 2)
Accordingly, the angle β formed by the flow velocity vector V1 which is a combined vector of Vr and Vω with respect to the circumferential component Vω is as shown in the following Expression 3.
β = tan ⁻¹ (Vr / Vω) (Equation 3)

  The cooling gas discharged from the cooling fan 8 is deflected in the direction along the outer surface of the frame 3 by the fan cover 9, and the flow velocity vector V2 after the deflection is parallel to the rotating shaft 5 as shown in FIG. It has a component Vp and a component Vv in the vertical direction. Since the ratio of the components of the flow velocity vector is substantially maintained before and after being deflected from the flow velocity vector V1 to the flow velocity vector V2, the angle formed by the flow velocity vector V2 with respect to the component Vv perpendicular to the rotating shaft 5 is also expressed by the above equation 3. Is approximately equal to the angle β.

  In the first embodiment, the radiator 31 has an angle of ± (π / 2−β) with respect to the rotating shaft 5 so that the radiator 31 is substantially parallel to the flow velocity vector V2 of the cooling gas flowing on the outer surface of the frame 3. Therefore, the interference between the cooling gas and the radiator 31 is reduced, and the cooling gas flows smoothly between the radiators 31. As a result, since the pressure loss when the cooling gas passes between the radiators 31 is reduced, the flow rate of the cooling gas increases. Further, since a radial fan is adopted and the shape of the heat radiating body 31 is a pin shape, the same operation can be obtained regardless of the rotation direction of the cooling fan 8 and the same effect can be obtained. Further, due to the component Vv in the direction perpendicular to the rotational axis 5 of the flow velocity vector V2 of the cooling gas, the cooling gas tends to leak out of the radiator 31, but the axis is so that the fan cover 9 covers all the radiators 31. Since it extends in the direction and is formed in a duct shape, the cooling gas reaches the heat dissipating body 31 disposed downstream of the flow of the cooling gas and contributes to heat dissipation.

  As a specific example of the first embodiment, the cooling fan 8 has a rotational speed of 1400 rpm, and the pin-shaped radiator 31 has a height of 10 to 15 mm and a diameter of 2 in consideration of formability by aluminum die casting. When the frame 3 is viewed from the front, the angle between the arrangement of the radiators 31 and the rotary shaft 5, that is, ± (π / 2−β) in FIG. 2 is about 80 °, and the arrangement interval of the radiators 31 is The temperature of the frame 3 of the motor (comparative example) in which the temperature rise of the frame 3 measured for the motor 1 of 2 to 18 mm is arranged with plate-shaped radiators of the same size arranged at intervals of 10 mm in the direction parallel to the rotation axis. The result compared with the rise is shown in FIG. The horizontal axis in FIG. 5 is the arrangement interval (mm) of the pin-shaped radiators 31, and the vertical axis is the arrangement interval of the radiators 31 with the temperature rise of the above embodiment when the temperature rise of the comparative example is 1. It is a relative value shown as a parameter.

  As is apparent from FIG. 5, in the case of the above-described embodiment, the arrangement interval of the pin-shaped radiators 31 is between about 8 to 12.5 mm, compared to a comparative example corresponding to a conventional device in which the radiators are plate-shaped. When the arrangement interval was about 10 mm, the temperature increase of the frame 3 was the smallest, and the temperature increase could be reduced by about 15%. The configuration of the above embodiment is merely an example for verifying the effect of the invention, and it goes without saying that the dimensions, material, angle, number of rotations of the cooling fan 8 and the like are not limited to the embodiment. In the description of the first embodiment, the heat dissipating body 31 has a pin shape, the heat dissipating body 31 is arranged substantially parallel to the flow velocity vector V2 of the cooling gas flowing on the outer surface of the frame 3, and the fan cover 9 is mounted on the frame. 3 has been described so as to cover all of the heat dissipating bodies 31 formed on the cover 3, and the intake port 9a of the fan cover 9 is formed into a honeycomb shape. Other than the above, even if the electric motor is the same as the conventional motor, a part of the cooling gas energized by the cooling fan 8 flows on the outer surface of the frame 3 along the direction of the flow velocity vector V2. The effect of the present invention is obtained in that the cooling effect is enhanced as compared with a plate-shaped radiator that does not generate a directional flow.

  As described above, according to the first embodiment, since the pin-shaped heat radiator 31 is provided on the outer peripheral surface of the frame 3, the cooling that increases the flow rate of the cooling gas and passes between the heat radiators 31. The flow rate of the gas is increased, heat exchange between the cooling gas and the radiator 31 is promoted, and the electric motor 1 can be effectively cooled. In addition, since the arrangement of the radiators 31 is arranged so as to be substantially parallel to the flow velocity vector V2 of the cooling gas flowing on the outer surface of the frame 3, the flow rate and flow velocity of the cooling gas are further increased, and the cooling of the electric motor 1 is performed. The effect is further increased. Further, since the fan cover 9 is formed in a duct shape so as to cover substantially the entire radiator 31, the distance that the cooling gas passes between the radiators 31 becomes long, and the cooling gas and the radiator 31 are increased. Heat exchange between the two is further promoted. Furthermore, since the intake port 9a of the fan cover 9 has a honeycomb shape, the pressure loss when the cooling gas passes through the intake port 9a is reduced, and the remarkable effect that the flow rate of the cooling gas flowing into the fan cover 9 is increased. can get.

Embodiment 2. FIG.
6 and 7 are views for explaining a fully-enclosed external fan motor as an example of a fully-enclosed external fan-shaped rotating electrical machine according to Embodiment 2 of the present invention. FIG. 6 is a longitudinal sectional view along the rotation axis, and FIG. FIG. 6 is a characteristic diagram showing the pressure loss characteristics measured for the fully-enclosed external fan motor shown in FIG. 6 in comparison with a conventional fully-enclosed external fan motor. In addition, the same part as Embodiment 1 attaches | subjects the same code | symbol, description is abbreviate | omitted, and only a different part is demonstrated. In the figure, a cylindrical pin-shaped heat radiating body 31A in the electric motor 1A is provided from the end surface portion on the non-load side of the outer peripheral surface of the frame 3 which is upstream of the flow of the cooling gas, to the intermediate portion of the frame 3 in the downstream direction. A plate-shaped radiator 32 is provided in parallel with the rotating shaft 5 at a portion downstream from the intermediate portion. The fan cover 9 </ b> A is provided so as to extend in a duct shape up to an intermediate portion of the frame 3 so as to cover the outer peripheral portion of the pin-shaped radiator 31 </ b> A. The pin-shaped radiator 31A is arranged substantially parallel to the flow velocity vector V2 of the cooling gas flowing on the surface of the frame 3 as in the first embodiment. Further, the heat radiating body 31A is not limited to a cylindrical shape, and may have other shapes such as a quadrangular column as long as it has a pin shape. Note that the fan cover 9A may be extended so as to cover up to the plate-shaped radiator 32.

  In the second embodiment, the frame 3 can be effectively cooled even when the dimension in the rotation axis direction of the frame 3 is large. That is, when the invention of the first embodiment is applied as it is to a model in which the dimensions of the frame 3 and the fan cover 9A in the rotation axis direction are large, the pressure loss due to the fan cover 9A becomes large, particularly in the downstream of the flow of the cooling gas. The attenuation of the component Vv in the direction perpendicular to the rotation axis 5 of the flow velocity vector V2 increases, and the component Vp in the direction parallel to the rotation axis 5 becomes dominant. In such a case, since the flow velocity vector V2 downstream of the cooling gas is substantially parallel to the rotation shaft 5, it is assumed that the heat radiation efficiency is better for the plate-shaped heat radiator than for the pin-shaped heat radiator. From this point of view, in the second embodiment, when the dimension in the direction of the rotation axis is large, a pin-shaped radiator 31A is disposed in a portion corresponding to the upstream of the flow of the cooling gas in the frame 3 to provide the flow velocity vector V2. The cooling effect by the component Vv in the direction perpendicular to the rotating shaft 5 is effectively utilized, and a plate-shaped radiator 32 is provided in the portion corresponding to the downstream of the flow of the cooling gas, and is governed by the flow velocity vector V2 in this region. The cooling effect by the component Vp in the direction parallel to the typical rotation shaft 5 is effectively utilized.

FIG. 7 compares an example of the effect of reducing the wind path pressure loss measured in order to confirm the cooling effect of the electric motor according to the second embodiment configured as described above with a conventional fully-enclosed external fan motor (comparative example). It is shown. In FIG. 7, the horizontal axis indicates the air volume (m ³ / min), the vertical axis indicates the pressure loss (mmAq), the curve A is the PQ characteristic that is the blowing characteristic of the cooling fan 8 used, and the curve B is the embodiment. 2 shows an RQ characteristic which is a pressure loss characteristic of the entire system of the electric motor 1A according to No. 2, and a curve C shows an RQ characteristic which is a pressure loss characteristic of the entire system of a conventional electric motor (not shown) used as a comparative example. As can be seen from FIG. 7, by using a pin-shaped radiator 31A and a plate-shaped radiator 32 together as a radiator formed on the outer peripheral surface of the frame 3, only a plate-shaped radiator is disposed as in the prior art. Compared with the case where it does, there exists an effect that 1 A of motors are cooled effectively by the air volume which passes between heat radiators increasing.

  In the first and second embodiments, the case where the rotating electrical machine is an electric motor has been described. Needless to say, the same effect can be obtained by using a generator. Further, the shape of the intake hole 9a, the blade shape of the cooling fan 8, the method of forming the frame 3, etc. are not limited to those exemplified. Further, in FIG. 2, the pin-shaped heat radiator 31 is illustrated so that the pins on the upper surface face in the same direction within a predetermined range in the circumferential direction in order to facilitate understanding of the invention. For example, it may be provided radially with respect to the rotating shaft 5. In addition, for example, it is natural that various modifications and changes can be made within the spirit of the present invention, for example, one of the brackets is formed integrally with the frame.

BRIEF DESCRIPTION OF THE DRAWINGS The longitudinal cross-sectional view which follows the rotating shaft of the full-closed external fan-shaped electric motor as an example of the full-closed external fan-shaped rotary electric machine which concerns on Embodiment 1 of this invention. The top view which shows the fully-closed outer fan type motor of the state which removed the fan cover shown by FIG. The front view which shows the fan cover shown by FIG. The front view which shows the fan shown by FIG. The characteristic view which shows the temperature rise of the flame | frame measured about the electric motor shown by FIG. 1 compared with the conventional electric motor (comparative example) which provided the plate-shaped heat radiator of the equivalent size. The longitudinal cross-sectional view which follows the rotating shaft of the full-closed outer fan type electric motor as an example of the full-closed outer fan-shaped rotary electric machine which concerns on Embodiment 2 of this invention. The characteristic view which shows the pressure loss characteristic measured about the electric motor shown by FIG. 6 in comparison with the conventional fully enclosed outside fan motor.

Explanation of symbols

  1, 1A Fully-enclosed fan motor (motor), 2 stator, 3 frame, 31, 31A (pin type) radiator, 32 (plate type) radiator, 4 rotor, 5 rotating shaft, 6A, 6B bearing 7A Load side bracket, 7B Anti-load side bracket, 8 Cooling fan, 81 blades, 9, 9A Fan cover, 9a Intake port, 9b Exhaust port.

Claims (6)

  A frame surrounding the stator, a plurality of radiators provided on the outer peripheral surface of the frame, a cooling fan attached to a rotating shaft protruding outside the machine, and an air current energized by the cooling fan And a fan cover that deflects the fan in a direction along the outer peripheral surface of the frame, wherein the radiator is formed in a pin shape.   2. The fully-enclosed external fan-shaped rotating electrical machine according to claim 1, wherein the pin-shaped heat radiator is arranged along a direction of a flow velocity vector of an airflow flowing on an outer peripheral surface of the frame.   The fully-enclosed external fan-type rotating electrical machine according to claim 1, wherein the fan cover is formed to extend in a downstream direction of the airflow so as to surround the pin-shaped heat radiator.   The fully-enclosed fan-shaped rotating electrical machine according to any one of claims 1 to 3, wherein a plate-shaped heat radiator is provided on an outer peripheral surface of the frame.   The fully-enclosed fan-shaped rotating electrical machine according to claim 4, wherein the pin-shaped heat radiator is provided in an upstream portion of the airflow, and the plate-shaped heat radiator is provided in a downstream portion of the airflow.   The fully-enclosed fan-shaped rotating electrical machine according to any one of claims 1 to 5, wherein the fan cover has a honeycomb-shaped through hole at an intake port.

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