JP3428864B2 - Electric motor with cooling fan - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an electric motor with a cooling fan.

[0002]

2. Description of the Related Art In an electric motor that converts electric energy into rotary power, heat is generated as a conversion loss when converting electric energy into rotary power. This heat thermally expands each component that constitutes the electric motor, and thus affects the rotational speed and the life of the electric motor. Particularly in the case of an electric motor used for an NC lathe or the like, the accuracy of the rotation speed greatly affects the processing accuracy of the lathe. Therefore, an electric motor equipped with a cooling fan for heat dissipation is widely used in order to prevent the temperature of each part of the electric motor from rising due to the above-mentioned heat. The cooling fan has a plurality of blades, a blade fixing member that fixes these blades, and a driving electric motor that rotates the blade fixing member. When the drive motor rotates and the plurality of blades rotate, the cooling gas passes through the plurality of cooling through holes formed in the stator core of the motor to cool the stator core. Generally, an axial fan that allows cooling gas to flow in the axial direction of the shaft of the drive motor or a so-called centrifugal fan that causes cooling gas to flow in the radial direction orthogonal to the axis of the shaft of the drive motor is used as the cooling fan. However, the axial fan has a characteristic that the air pressure is small although the air volume is large. Further, the centrifugal fan has a characteristic that the air pressure is large but the air volume is small. The conventional motor with a cooling fan that cools the stator core using the cooling fan having such characteristics has a limit in reducing noise. This is because, in order to obtain a desired air volume and air pressure, it is necessary to use a large cooling fan (which has a high blowing capacity) as the blowing fan, which causes more noise than a small cooling fan. Therefore, the present inventor, as shown in Japanese Patent Application No. 9-155216, is configured to positively discharge the sucked gas in an oblique direction between the axial direction and the radial direction of the output shaft of the drive motor. It was proposed to use a flow fan. Since the mixed flow fan has characteristics intermediate between those of the axial flow fan and the centrifugal fan, it is possible to obtain a desired air volume and pressure with a mixed flow fan that is smaller than the conventional axial flow fan or centrifugal fan. it can. As a result, when the mixed flow fan is used as the cooling fan, noise can be reduced more than before.

[0003]

Although it is possible to reduce noise by using a mixed flow fan as the cooling fan, it is required to further reduce noise.

An object of the present invention is to provide an electric motor with a cooling fan which can reduce the noise of the cooling fan.

Another object of the present invention is to provide an electric motor with a cooling fan in which an object that is easily affected by hot air can be placed outside the discharge port in the axial direction.

[0006]

SUMMARY OF THE INVENTION An electric motor with a cooling fan, which is an object of improvement of the present invention, is an electric motor main body in which a plurality of cooling through holes through which cooling gas passes is formed in a stator core, and an output of the electric motor main body. A cooling fan that is provided so that the suction port is located on the end side opposite to the end where the shaft projects, and applies a suction pressure to the cooling gas that passes through the plurality of cooling through holes,
The duct includes a gas flow passage that connects the plurality of cooling through holes and the ventilation passage of the cooling fan. The cooling fan includes a plurality of blades, a blade fixing member to which the plurality of blades are fixed on an outer peripheral portion, a driving electric motor for rotating the blade fixing member, and a ventilation fan inside the periphery of the plurality of blades. It has a casing forming a passage, and a plurality of webs connecting the driving motor and the casing.

In the present invention, the cooling fan is a mixed flow fan configured to positively discharge the sucked gas in an oblique direction between the axial direction and the radial direction of the output shaft of the drive motor.

A guide plate is provided between the discharge port of the cooling fan and the discharge port so as to guide the gas discharged from the discharge port in a predetermined direction, and the guide plate is the discharge port. The gas discharged from is directed substantially in the radial direction.

According to this structure , the gas discharged from the discharge port is discharged in the radial direction with respect to the axial direction of the output shaft of the drive motor, so that the gas is discharged in the centrifugal direction of the output shaft. Will be. Therefore, it is possible to smooth the gas flow and reduce the noise of the cooling fan. Moreover, the cooling efficiency can be increased because the wind velocity of the gas increases. Further, since the gas discharged from the discharge port is hot air, there is an advantage that an object that is easily affected by the hot air can be arranged outside the discharge port in the axial direction.

[0010] opposing wall surfaces facing the discharge port of the guide plate has a curved surface of the annular curved to be convex toward the direction away from the discharge opening, radially outward continuously in該湾curved surface extending configured as an annular plane, curved to direct the gas discharged curved surface from the discharge port in a radial direction. With this configuration, the gas discharged from the discharge port can be gently discharged in the radial direction of the output shaft of the drive motor without giving resistance to the gas.

[0011] curvature of this case, the end portion of the discharge port side of the casing form shapes <br/> the flange portion of the annular extending toward the outside in the radial direction, the guide plate on the inner peripheral side corner portion of the flange portion surface forms a curved surface of the annular curved to be convex in the same direction as a convex. By doing so, the gas discharged from the discharge port can be discharged more gently.

The radius of curvature R1 of the curved surface of the guide plate is made larger than the radius of curvature R2 of the curved surface of the flange portion, and the minimum dimension between the flange portion and the plane of the guide plate is L.
When set to 1 , 1.50 × L1 ≦ R1 ≦ 1.85 × L
Relationship 1 and 0.50 × L1 ≦ R2 ≦ 0.85 × L1 is so established. If R1 is less than 1.50 × L1 , there is a problem that stagnation occurs due to the flow of gas. R1 is 1.8
If it exceeds 5 × L1 , there is a problem that the flow of gas changes rapidly at the time of discharge. Further, if R2 is less than 0.50 × L1 , there is a problem that the flow of gas changes rapidly during discharge. If R2 exceeds 0.85 × L1 , the flow of gas in the radial direction is not smooth, and there is a problem that eddy sulfur occurs. So
Therefore, if R1 and R2 are set as above, cooling
Stagnation may occur due to the flow of gas discharged from the fan,
Prevents the gas flow from changing rapidly during discharge ,
The flow of gas can be made smooth. Further, it is preferable to set R1 and R2 as described above in view of the demand for downsizing the cooling fan.

As a mixed flow fan used for cooling an electric motor,
As a result of the inventor's earnest research on what kind of mixed flow fan should be used, it has been found that it is preferable to use a mixed flow fan that satisfies at least the following two requirements.

(1) The outer peripheral surface of the outer peripheral portion of the blade fixing member is inclined so that the inclination angle with the axis of the output shaft of the drive motor is 30 ° to 45 °.

(2) The inner wall portion of the casing is inclined in the same direction as the outer peripheral portion of the blade fixing member, and the inclination angle between the inner wall portion and the axis is between the axis and the outer peripheral surface of the outer peripheral portion of the blade fixing member. Be tilted to be smaller than the tilt angle.

When the inclination angle of the outer peripheral portion of the fixing member is less than 30 °, the characteristics are close to those of the above-described axial flow fan, and when the inclination angle exceeds 45 °, the characteristics are close to those of the centrifugal fan, and the small inclined fan is used. It is difficult to obtain a desired air volume and air pressure with a flow fan.

As a result of searching for a more preferable angle in the above angle range, the inclination angle between the outer peripheral surface of the outer peripheral portion of the blade fixing member and the axis of the output shaft of the drive motor is 35 ° ±.
It has been found that it is preferable to incline the outer peripheral surface of the outer peripheral portion of the blade fixing member so that the blade fixing member has an angle of 3.5 °. Within this angle range, a desired air volume and air pressure can be obtained without increasing the size of the mixed flow fan. Even with a mixed flow fan that is out of the preferable angle range and falls within the wide angle range described above, noise can be reduced and size can be reduced as compared with the case of using an axial flow fan or a centrifugal fan. Compared with the above-mentioned mixed flow fan having a more preferable angle range, the cooling capacity and the noise characteristic are deteriorated.

The attachment angle of the plurality of blades to the blade fixing member can be arbitrarily determined according to the shape of the blade. However, when the number of blades is 7, the more preferable cooling capacity and noise characteristics can be obtained by setting the angle as follows. That is, each of the plurality of blades is connected to a blade fixing member with a virtual connecting line connecting one end located on the suction port side and the other end located on the discharge port side of the mounting side, and a drive line. The angle between the axis of the output shaft of the electric motor and an imaginary plane that includes one end of the mounting side portion in the plane intersects the outer circumferential surface of the blade fixing member and the virtual intersecting line formed on the outer circumferential surface is 50 ° ±. It is attached to the blade fixing member at an angle of 2.5 °. By doing so, the air volume can be set to a value close to the maximum and the noise can be set to a value close to the minimum.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a half sectional view of an example of an embodiment in which the present invention is applied to an induction motor with a cooling fan. FIG. 1 is an upper half sectional view of an electric motor. This electric motor has an electric motor main body 1, a duct 3, and a cooling fan 5 connected to the electric motor main body 1 by the duct 3.

The electric motor body 1 has a shaft 7 forming an output shaft, a rotor 9 fixed to the shaft 7, a stator 11, a pair of end brackets 13 and 15, and a rotation detector 17. . The shaft 7 is composed of four shaft portions 7a to 7d having different diameters, and the shaft portion 7a constitutes an output portion. The shaft 7 is rotatably supported by the pair of end brackets 13 and 15 by bearings 19 and 21 attached to the shaft portions 7b and 7d, respectively. A rotor 9 is fixed to the outer circumference of the shaft portion 7c having the largest diameter dimension, which is located between the shaft portions 7b and 7d. The rotor 9 is a cage rotor.

The stator 11 comprises a stator core 11a and a winding 11b wound around the stator core 11a. Stator core 11a
2, which is a sectional view showing the stator core 11a as viewed from the line II-II in FIG. 1, has an octagonal tubular shape with a circular internal hole 11k. Bearings 1 that support both ends of the shaft 7 in the axial direction at both ends
A pair of end brackets 13 and 1 to which 9 and 21 are fixed
5 is fixed. FIG. 2 is a cross-sectional view showing the stator core 11a and shows the shapes of a plurality of silicon steel plates forming the stator core 11a. This stator core 11a
Is formed by laminating a plurality of silicon steel plates in the axial direction of the shaft 7.

As shown in FIG. 2, the plurality of silicon steel plates constituting the stator core 11a have eight side portions forming an octagonal contour shape on the outer peripheral portion. Specifically, it has four long side portions 11c ... And four short side portions 11d ... Positioned between the adjacent long side portions 11c, 11c. In other words, the short side portions 11d ... are the four long side portions 11c.
The corners that connect ... Are formed. The plurality of silicon steel sheets each have through-hole forming regions 12a ... Adjacent to the four corner portions (portions corresponding to the short side portions 11d ...) And between the through-hole forming regions. (Long side 1
1c ...) has intermediate regions 12b. Further, an annular yoke portion is provided inside the through hole forming regions 12a ... And the intermediate regions 12b. Inside the yoke portion, the stator winding 11
a plurality of slots 11 into which the winding conductors constituting b are inserted
g are formed at intervals in the circumferential direction. Note that FIG.
In the figure, some of the plurality of slots 11g are drawn, and the other slots 11g are omitted.

In the through hole forming region 12a, five corner through holes 11e1 to 11e5 forming cooling through holes for passing the cooling gas through the stator iron core 11a are arranged side by side along the short side portions 11d. Each is formed. The intermediate through-hole 12b between the two through-hole forming areas 12a is also provided with cooling through-holes for passing the cooling gas through the stator core 11a.
The two intermediate through holes 11f1 to 11f4 are the long side portions 11c.
They are formed side by side along the line. Corner through holes 11e1 to 11e5 and intermediate through hole 11f1
The shapes and dimensions of 11f4 are set so as not to reduce the magnetic resistance of the yoke portion.

By laminating a plurality of silicon steel plates, the corner through holes 11e1 to 11e5 formed in each steel plate are formed.
Thus, a plurality of cooling through holes 11i ... Is formed at each corner of the stator core 11a, and each intermediate portion through hole 11 is formed.
Due to f1 to 11f4, a plurality of cooling through holes 11j in the middle portion, which are not conventional stator cores, are formed. In FIG. 1, the cooling through holes 11i located at the corners are shown.
Only shown.

Cooling through holes 11i ... and Cooling through holes 1
1j ... The cooling gas for cooling the stator core 11a is rotated by the blade 37 of the cooling fan 5.
Flow in the direction shown in. A gas inlet (11i1) for sucking the cooling gas is formed on the side of the cooling through-hole 11i ... And the cooling through-hole 11j ... where the shaft 7 projects (the side of the shaft portion 7a through which the output of the motor is taken out). (In FIG. 1, the gas inlet 11i1 of the cooling through hole 11i
Only shown).

The rotation of the shaft 7 is provided on the outer side of the other end bracket 15 located on the side opposite to the one end bracket 13 located on the side where the shaft 7 projects (the side of the shaft portion 7a for taking out the output of the motor). A rotation detector 17 for detecting is arranged. The rotation detector 17 is composed of, for example, an optical encoder. The rotation detector 17 is a detector body 17 a connected to the shaft 7.
And a cover member 17b for protecting the detector body 17a. The cover member 17b has a so-called cup shape and has a cylindrical inclined portion 17c that faces the duct 3. The end of the inclined portion 17c is connected to the end of the end bracket 15. A surface of the end bracket 15 and the inclined portion 17c of the cover member 17b that faces the duct 3 forms a gently inclined surface that approaches the axis of the shaft 7 from the stator iron core 11a side toward the cooling fan 5 side. There is.

The duct 3 is provided between the end bracket 15 and the cover member 17b of the rotation detector 17 so that the gas flow passage 2 is formed.
3 has a tubular shape forming 3. Gas flow passage 23
Communicate with the cooling through holes 11i ... And the cooling through holes 11j. The duct 3 has a rectangular tubular portion 3a having a rectangular cross section.
And a diameter-reduced cylindrical portion 3b whose diameter is reduced continuously toward the end of the rectangular cylindrical portion 3a. The end of the rectangular tube portion 3a is connected to the stator core 11a by welding or screwing. Further, the reduced diameter cylindrical portion 3b faces the cover member 17b, and the stator core 11
The outer surface is inclined so that the diameter dimension decreases from the a side toward the cooling fan 5 side. The end of the reduced diameter cylindrical portion 3b is
It is connected to the casing 29 of the cooling fan 5.

The duct 3, the end bracket 15, and the cover member 17b are dimensioned and dimensioned so that the gas flow passage 23 approaches the axis of the shaft 7 from the stator core 11a side toward the cooling fan 5 side, and the cross-sectional area increases. The shape is fixed. Inside the reduced-diameter cylindrical portion 3b of the duct 3, a plurality of (20) stationary blades 25 that divide the gas flow passage 23 into a plurality of portions in the circumferential direction are arranged. The vane 25 has a shape close to a rectangle, and is fixed to the inner wall portion of the duct 3 so as to open a slight gap between the end bracket 15 and the outer surface of the cover member 17b.

As shown in detail in FIGS. 3 to 5, the cooling fan 5 has a structure in which a fan body 27 and a casing 29 are connected by a plurality of webs 31 ... The end where the 7 projects (the shaft part 7
The suction port 5a is provided on the end side opposite to the (a side) side. 3 is an enlarged cross section of the cooling fan 5 shown in FIG. 1, and FIG. 4 is a plan view of the blade fixing member 35 to which the blades 37 of the fan body 27 are attached as seen from the duct 3 side of FIG. Yes, FIG. 5 is a plan view of the cooling fan 5 viewed from the right side (the ejection port 5b side) toward FIG. Here, both FIG. 4 and FIG. 5 depict not only the upper half but the entire upper and lower parts. 5 is a plan view of the cooling fan 5 in which the upper half portion is shown with the guide plate 55 removed, and the lower half portion actually includes the guide plate 55. FIG.

As shown in FIG. 3, the fan body 27 includes a driving electric motor 33, a blade fixing member 35, and a blade fixing member 3.
5 and a plurality of blades 37 ... The drive motor 33 is composed of a known induction motor, and includes a shaft (output shaft) 39, an annular flywheel 43 fixed to the shaft 39, and a flywheel 4.
3, the rotor 41 fixed to the motor bracket 45 and the motor bracket 45
And a stator 47 fixed to the motor bracket 45. The shaft 39 is arranged so as to share the axis with the shaft 7 of the electric motor body 1, and is rotatably supported by the motor bracket 45 by bearings 49 and 51.

The rotor 41 is a cage-shaped rotor like the rotor of the electric motor body 1. Although an induction motor is used as the driving motor 33 in the present embodiment, a brushless DC motor of a type using a permanent magnet or the like may be used as the driving motor 33. Motor bracket 45
Has a structure in which the inner tubular wall portion 45a, the intermediate tubular wall portion 45b, and the outer tubular wall portion 45c are connected by a connecting wall portion 45d. A guide plate 55, which will be described later, is attached to the connecting cylindrical wall portion 45d. The inner tubular wall portion 45a constitutes a bearing holder, and bearings 49, 5 for rotatably supporting the shaft 39 therein are provided.
1 is attached. The end of the intermediate tubular wall portion 45b has a U-shaped cross section for accommodating the end portion 43b1 inside the end portion 43b1 of the blade fixing member mounting portion 43b of the flywheel 43 at a distance. An annular recess 45b1 is formed. Cylindrical end 43b1 and annular recess 4
A labyrinth structure is formed by loosely fitting with 5b1. The outer cylindrical wall portion 45c has an end portion which is the blade fixing member 3
5 is arranged along the tubular end portion 35c so as to form a slight gap with the tubular end portion 35c. A plurality of (four in this example) webs 31 ... Are integrally formed with the motor bracket 45 on the outer peripheral portion of the outer cylindrical wall portion 45c (FIG. 5). These webs 31 ...
9 is connected to the annular flange portion 29b. As a result, the motor bracket 45 is supported by the casing 29 via the webs 31 ... The opening between the flange portion 29b and the motor bracket 45 constitutes the discharge port 5b through which the cooling gas for cooling the stator core 11a is discharged. A stator 47 is arranged in a space surrounded by the inner tubular wall portion 45a, the intermediate tubular wall portion 45b, and the connecting tubular wall portion 45d of the motor bracket 45. Stator 47
Is constituted by winding a winding wire 47b around a stator iron core 47a.

An annular flywheel 43 is fixed to the outer end of the bearing 49 of the shaft 39 (the end on the electric motor body 1 side). The flywheel 43 has a structure in which a base portion 43a to which the shaft 39 is attached and a blade fixing member attachment portion 43b are connected by a connecting portion 43c. The blade fixing member mounting portion 43b has an annular concave portion that opens toward the stator 47 side. Inside the annular recess, one winding portion of the winding 47b of the stator 47 is arranged so as to be spaced a predetermined distance from the inner wall surface of the blade fixing member mounting portion 43b. The mounting disk portion 35a of the blade fixing member 35 is fixed to the radially outer end of the blade fixing member mounting portion 43b.

The blade fixing member 35 is a flywheel 43.
An annular mounting disk portion 35a fixed by screws or welding to one end portion in the axial direction of, and a cylindrical blade fixing portion 35 in which seven blades 37 are fixed to the outer peripheral portion or the outer peripheral surface.
b and a cylindrical end portion 35c that faces the outer wall portion 45c of the motor bracket 45 at a slight interval and are integrally formed. The mounting disk portion 35a extends in the radial direction of the shaft 39 of the driving electric motor 33, and has a cylindrical end portion 3a.
5c extends in the axial direction of the shaft 39 of the drive motor 33. The outer peripheral portion of the blade fixing portion 35b has a cylindrical shape or a trumpet shape inclined so that the diameter dimension increases from the suction side (suction port 5a) of the cooling gas toward the discharge side (discharge port 5b side). is doing. Specifically, the outer peripheral surface of the blade fixing portion 35b is inclined so that the inclination angle θ1 between the axis of the shaft 39 of the drive motor 33 and the outer peripheral surface falls within the angle range of 35 ° ± 2 °. There is. Since the shaft 39 of the driving electric motor 33 and the shaft 7 of the electric motor main body 1 share an axis, the outer peripheral surface of the blade fixing portion 35b is also 35 ° ± 2 ° with respect to the axis of the shaft 7 of the electric motor main body 1.
It means that it is inclined at an angle of.

The outer peripheral surface of the blade fixing portion 35b and the shaft 3
The inclination angle θ1 with respect to the axis of 9 is preferably set within the range of 30 ° to 45 °. With this tilt angle,
The cooling fan 5 is a mixed flow fan having characteristics suitable for cooling the stator core 11a of the electric motor. The cooling gas sucked from the gas intake ports 11i1 of the plurality of cooling through holes of the stator core 11a by the rotation of the blades 37 is sucked into the suction port 5
From a to the discharge port 5b of the cooling fan, positive discharge is performed in an oblique direction between the axial direction and the radial direction of the shaft 39 of the drive motor 33. As shown in FIG. 4, each of the seven blades 37 has a strip-shaped metal plate attached to the outer peripheral surface of the blade fixing portion 35b, and the base portion (mounting side portion) thereof is attached to the blade fixing portion 35b.
It is welded to the outer peripheral surface of b and is fixed to the outer peripheral portion of the blade fixing portion 35b. Although the blade 37 is welded to the blade fixing member 35 in the present embodiment, the blade 37 and the blade fixing member 35 may be fixed by other means. Also, the blade 37
May be formed of synthetic resin or the like and integrally formed with the blade fixing member 35. Each blade 37 has a side portion 37 on the opposite side of the side portion 37a of the blade 37 that is attached to the blade fixing portion 35.
It has a shape such that b is substantially parallel to the inner wall of the casing 29.

The mounting state of each blade 37 will be described.
The attachment side portion 37a of each blade 37 has one end portion 37c located on the suction side of the cooling fan 3 and the other end portion 37d located on the discharge side of the cooling fan 3. A virtual connecting line connecting these two end portions 37c and 37d is LA1.
As shown in FIG. The axis of the shaft 39 of the drive motor 33 and the one end 3 of the attachment side 37a of the blade 37
7c and an imaginary plane including 7c in the plane and the outer peripheral surface of the blade fixing member 35 intersect with each other to form an imaginary line of intersection (a line extending in the direction in which the cooling gas flows) LA2 and the virtual connecting line described above. The blades 37 are attached to the blade fixing portion 35 so that the angle θ3 with the LA1 is in the range of 50 ° ± 2.5 °. In this example, the angle θ3 is approximately 50 °. If such a mounting structure is adopted, the angle θ3 will be 50
In the range of ± 2.5 °, the air volume is close to the maximum value and the noise is close to the minimum value. Note that, since FIG. 4 is a diagram in which a solid is converted into a plane, the angle of θ3 shown in the drawing is different from the actual angle of θ3.

The casing 29 is a casing body 29a.
And a flange portion 29b. Although the flange portion 29b constitutes a part of the casing 29, it is integrally formed with the webs 31 ... In this example. Of course, the flange portion 29b may be integrally formed with the casing body 29a. Casing body 29a
Is a flange-side mounting portion (flange portion) 29c, a ventilation passage forming portion 29d, and a duct-side mounting portion (flange portion) 29.
and e. Flange side mounting part 29
Both c and the duct side attachment portion 29e have an annular disc shape and extend in the radial direction of the shaft 39.
The flange portion 29b and the duct 3 are screwed to each other. Therefore, in these members, a plurality of through holes through which screws pass are formed at intervals in the circumferential direction. The ventilation passage forming portion 29d is the blade fixing portion 35 of the blade fixing member 35.
It has a tubular shape that forms an annular ventilation passage 59 between the b and b. The inner wall portion of the ventilation passage forming portion 29d is inclined in the same direction as the outer peripheral portion of the blade fixing portion 35b is inclined. That is, the ventilation passage forming portion 29d is the duct side mounting portion 2
The diameter is enlarged such that the diameter increases from 9e toward the flange-side mounting portion 29c. Ventilation path forming part 29d
The inclination angle θ2 between the inner wall of the blade and the axis of the shaft 39 of the drive motor 33 is smaller than the inclination angle θ1 of the outer peripheral portion of the blade fixing portion 35b. In this example, this angle θ2 is 25 °.

The flange portion 29b is formed at the end portion of the casing 29 on the discharge port 5b side, and has an annular shape extending outward in the radial direction of the shaft 39. An annular curved surface 29b1 that is curved so as to be convex in the same direction as the curved surface 55c1 of the guide plate 55 described later is formed at the corner portion on the inner peripheral side of the flange portion 29b.

The guide plate 55 attached to the connecting cylindrical wall portion 45d includes an attaching portion 55a and an opposing wall portion 55b.
And have. The mounting portion 55a is formed in an annular shape. As shown in FIG. 5, the mounting portion 55 a is screwed to the connecting wall portion 45 d of the motor bracket 45 with the screw N, and the guide plate 55 is attached to the motor bracket 45. The opposing wall portion 55b is formed radially outward from the attachment portion 55a. A facing wall surface 55c is formed on the side of the mounting portion 55a facing the discharge port 5b. The opposed wall surface 55c is an annular curved surface 55c1 that is curved so as to be convex in a direction away from the discharge port 5b.
And an annular flat surface 55c2 continuous with the curved surface 55c1 and extending radially outward. The curved surface 55c1 is curved so that the gas discharged from the discharge port 5b is directed in the radial direction. The radius of curvature R1 of the curved surface 55c1 is equal to the curved surface 29b1 of the flange portion 29b.
Is formed to be larger than the radius of curvature R2. When the minimum dimension between the flange portion 29b and the flat surface 55c2 of the guide plate 55 is L1,
1.50 × L1 ≦ R1 ≦ 1.85 × L1 and 0.50 ×
In order that the relation of L1 ≦ R2 ≦ 0.85 × L1 is established,
The size and shape of the flange portion 29b and the guide plate 55 are set. Further, the minimum dimension L2 of the distance between the inner wall surface of the ventilation passage forming portion 29d of the casing 29 and the outer peripheral surface of the blade fixing member 35 is substantially equal to L1.

Next, an electric motor with each cooling fan of the present embodiment having a radius of curvature R1 of 0 mm and 50 mm and an electric motor with a cooling fan of the same structure as the present embodiment except that the guide plate 55 is not provided. I prepared. In addition, the cooling fan having a radius of curvature R1 of 0 mm is used in the guide plate 55
The opposing wall portion 55b 'of ′ is formed without being curved as shown in FIG. Further, the dimension L1 of each electric motor is 30
mm. Then, the drive motor 33 is set to 200V, 6
Rotation was carried out at 0 Hz, and the relationship between the air volume and noise of each electric motor and the relationship between the air volume and static pressure were examined. FIG. 6 shows the measurement result. From this figure, it can be seen that the electric motor equipped with the guide plate can reduce noise and increase static pressure. In particular, it can be seen that an electric motor having R1 of 50 mm can reduce noise and increase static pressure.

[0040]

According to the present invention, the ink is discharged from the discharge port.
It can be in the flow of the gas body to smoothly lower the noise of the cooling fan. Moreover, the cooling efficiency can be increased because the wind velocity of the gas increases. Further, since the gas discharged from the discharge port is hot air, there is an advantage that an object that is easily affected by the hot air can be arranged outside the discharge port in the axial direction.

[Brief description of drawings]

FIG. 1 is a half sectional view of an example of an electric motor with a cooling fan according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the stator core 11a as seen from the line II-II in FIG.

FIG. 3 is a partially enlarged sectional view of the cooling fan shown in FIG.

FIG. 4 is a plan view of a blade fixing member to which blades are attached as seen from the duct side in FIG.

5 is a plan view of the cooling fan seen from the right side in FIG. 1. FIG.

FIG. 6 is a diagram showing the relationship between the air volume and the sound (noise) of the electric motor used in the test, and the relationship between the air volume and the static pressure.

FIG. 7 is a diagram showing an example of a radius of curvature R1 = 0 mm.

[Explanation of symbols]

1 Electric motor body 3 ducts 5 cooling fan 7 shaft (output shaft) 11i ..., 11j ... Through holes for cooling 29 casing 29b Flange part 29b1 curved surface 31 ... Web 33 Drive motor 35 blade fixing member 37 ... feather 39 Shaft (output shaft) 55 Guide plate 55c facing wall 55c1 curved surface 55c2 plane

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hideo Kiyomi 1-5-15-1 Kitaotsuka, Toshima-ku, Tokyo Sanyo Electric Co., Ltd. (56) Reference JP-A-7-245913 (JP, A) JP-A-6-213198 (JP, A) JP-A-9-154256 (JP, A) JP-A-7-119685 (JP, A) JP-A-55-160952 (JP, A) JP-A-55-51995 (JP, A) Actual development 63-202154 (JP, U) Actual development 57-66416 (JP, U) Actual development 64-11397 (JP, U) (58) Fields investigated (Int.Cl. ⁷⁾ , DB name) H02K 9/00-9/28 F04D 17/00-23/00 F04D 25/00-25/16 F04D 29/18-29/70

Claims (5)

(57) [Claims] 1. A motor main body having a plurality of cooling through holes formed in a stator core through which a cooling gas passes, and a suction port on an end side opposite to an end where an output shaft of the motor main body projects. A cooling fan that is provided so as to be positioned to apply suction pressure to the cooling gas that passes through the plurality of cooling through holes,
A duct that constitutes a gas flow passage that connects the plurality of cooling through holes and the ventilation passage of the cooling fan, wherein the cooling fan has a plurality of blades, and the plurality of blades has an outer peripheral surface. A blade fixing member fixed to, a driving electric motor for rotating the blade fixing member, a casing that surrounds the periphery of the plurality of blades and forms the ventilation passage inside, a driving electric motor and the casing. A motor with a cooling fan comprising a plurality of webs to be coupled, wherein the sucked gas is positively acted in an oblique direction between an axial direction and a radial direction of an output shaft of the driving electric motor as the cooling fan. A mixed flow fan configured to discharge is used, and is arranged at a predetermined distance from the discharge port of the cooling fan to guide the gas discharged from the discharge port in a predetermined direction. That the guide plate is provided, wherein the guide plate is configured to direct gas discharged from the discharge port substantially the radial direction, opposite the wall that faces the discharge opening of the guide plate
Is to be convex in the direction away from the discharge port.
An annular curved surface that bends in an inward direction and a radial direction that is continuous with the curved surface
An annular flat surface extending toward the outside, and the curved surface allows the gas discharged from the discharge port to be in the radial direction.
It is curved so as to face in the direction, and the end portion on the discharge port side of the casing has the radial direction.
An annular flange portion that extends toward the outside is formed, and an inner peripheral side corner portion of the flange portion has the guide plate of the guide plate.
So that the curved surface is convex in the same direction as it is convex
An annular curved surface that curves is formed, and the radius of curvature R1 of the curved surface of the guide plate is
Greater than the radius of curvature R2 of the curved surface of the flange portion, between the flange portion and the plane of the guide plate
1.50 × L1 ≦ R1 where L1 is the minimum dimension of
≦ 1.85 × L1 and 0.50 × L1 ≦ R2 ≦ 0.85
XL1 relationship is established, with cooling fan
Electric motor. 2. The outer peripheral surface of the blade fixing member is
The inclination angle between the drive motor and the axis of the output shaft is 3
It is inclined so as to form an angle of 0 ° to 45 °, and the inner wall surface of the casing is different from the direction in which the outer peripheral surface is inclined.
Inclined in the same direction and the angle of inclination with the axis is
Inclined to be smaller than the inclination angle of the outer periphery
Electric with a cooling fan according to claim 1, characterized in that
Machine. 3. The outer peripheral surface of the blade fixing member is the
The inclination angle between the drive motor and the axis of the output shaft is 3
Be sure to incline so that the angle is 5 ° ± 3.5 °
The electric motor with a cooling fan according to claim 2, which is characterized in that. 4. The inner wall surface of the casing and the blade
The minimum dimension L2 of the space between the fixing member and the outer peripheral surface is
4. The method according to claim 3, which is substantially equal to L1.
Electric motor with cooling fan. 5. The plurality of blades are respectively the blades.
On the suction port side of the mounting side that is attached to the root fixing member
One end located and the other end located on the discharge port side
And a virtual connecting line connecting the parts and the output of the drive motor.
The axis of the shaft and the one end of the mounting side are included in the plane.
The imaginary surface intersects the outer peripheral surface of the blade fixing member, and
The angle between the virtual intersection line formed on the peripheral surface is 50 ° ± 2.
7 attached to the wing fixing member so as to form an angle of 5 °
The cooling device according to claim 4, wherein the cooling device is composed of a single blade.
Electric motor with cooling fan.