JP3428859B2 - Electric motor with cooling fan and cooling fan - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric motor with a cooling fan and 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. FIG. 8 shows only the upper half of the cross section of a conventional electric motor with a cooling fan. It should be noted that this drawing is a cross-sectional view of the electric motor with a cooling fan placed in a normal installation state and cut obliquely. That is, the electric motor main body 2
The stator core 204 of No. 01 has a rectangular contour shape, and the upper half of the cross-sectional view of the stator core 204 cut diagonally is shown. This conventional electric motor with a cooling fan has a structure in which an electric motor main body 201 and a cooling fan 202 are connected by a duct 203. The stator core 204 of the electric motor main body 201 includes the stator core 2
A plurality of cooling through holes 2 through which the cooling gas for cooling 04 passes
05 are formed at four corners of the stator core 204 at intervals in the circumferential direction. The cooling fan 202 has a plurality of blades 206, a blade fixing member 207 having the plurality of blades 206 fixed to the outer peripheral portion, and a driving electric motor 208 that rotates the blade fixing member 207. When the blades 206 of the cooling fan 202 rotate, cooling gas flows through the cooling through holes 205 ... In the direction from the stator core 204 side toward the cooling fan 202 side as shown by the arrow F, and the stator core 204 is cooled. To be done. In this electric motor, the cooling fan 202 is configured by an axial fan that allows a cooling gas to flow in the axial direction of the shaft of the driving electric motor 208. In addition to the type shown in this figure, there is also proposed an electric motor with a cooling fan in which a so-called centrifugal fan, which flows a cooling gas in a radial direction orthogonal to the axis of the shaft of the driving electric motor 208, is attached as a cooling fan.

[0003]

The axial-flow fan used in the conventional electric motor shown in FIG. 8 has a characteristic that the air volume is large but the air pressure is small. The centrifugal fan described above has a characteristic that the air pressure is large but the air volume is small. In the conventional electric motor with a cooling fan that cools the stator core 204 by passing the cooling gas through the cooling through hole 205 formed in the stator core 204 of the electric motor body 201 using the cooling fan having such characteristics, noise is reduced. There was a limit to that. 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. In addition, when a large cooling fan is used, the size of the cooling fan is inevitably increased due to the increase in size of the cooling fan.

Further, in the conventional electric motor with a cooling fan,
The cooling through holes 205 ... Are formed only at the corners of the stator core 204 having the rectangular contour shape of the electric motor body 201. This was to avoid the formation of a through hole in the intermediate region between the four corners, which would result in the through hole being formed in the yoke portion of the stator core, that is, the magnetic passage portion. However, when the cooling through holes 205 are formed only in the four corner regions, the temperature of the intermediate region located between the two corners becomes high, and this temperature is particularly high in the end bracket 209 on the shaft side. It has been a cause of raising the temperature of the equipment on the side where the electric motor is attached.

It is an object of the present invention to provide a cooling fan-equipped electric motor and a cooling fan which can reduce the size of the cooling fan and reduce the noise of the cooling fan.

Another object of the present invention is to provide an electric motor with a cooling fan and a cooling fan which can reduce the axial dimension of the electric motor with a cooling fan.

Another object of the present invention is to provide an electric motor with a cooling fan and a cooling fan capable of suppressing an increase in temperature of a stator core of an electric motor body and suppressing an increase in temperature of a device to which the electric motor is attached. is there.

[0008]

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 on the end side opposite to the end where the shaft projects and applies pressure to the cooling gas that passes through the plurality of cooling through holes, and a ventilation path for the plurality of cooling through holes and the cooling fan. And a duct that forms a gas flow path that connects the and. 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, as the cooling fan, 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 is used. More specifically, a plurality of blades, a blade fixing member that is fixed to the rotor and has a plurality of blades fixed to an annular outer peripheral portion, and a driving electric motor that rotates the rotor,
It is provided with a tubular casing that surrounds a plurality of blades and forms a ventilation path inside, and a plurality of webs that connect the driving electric motor and the casing, and the outer peripheral portion (or outer peripheral surface) of the blade fixing member is It has a shape that inclines so that the diameter size increases from the suction side to the discharge side, so that the sucked gas is positively discharged in an oblique direction between the axial direction and the radial direction of the output shaft of the drive motor. In addition, a plurality of blades are fixed to the outer peripheral portion.

In order to obtain a desired air volume and pressure with the axial flow fan and the centrifugal fan used as the conventional cooling fan, it is necessary to use a large noise fan (having a high cooling capacity) as the cooling fan. . If the desired air volume and air pressure can be obtained with a small cooling fan, the noise generated from the cooling fan itself can be reduced. Further, if the cooling fan can be made smaller, the axial dimension of the electric motor can be reduced accordingly. Therefore, the inventor has studied whether it is possible to reduce noise by using another cooling fan that has not been conventionally used for cooling an electric motor, without sticking to the conventional wisdom. As a result, we discovered a mixed flow fan. The mixed flow fan has a characteristic intermediate between those of an axial flow fan and a centrifugal fan. Then, the desired air volume and air pressure can be obtained with a mixed-flow fan that is smaller than the conventional axial fan or centrifugal fan. As a result, when the mixed flow fan is used as the cooling fan, noise can be reduced as compared with the conventional case.

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 such that the angle of inclination 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 is inclined, 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-mentioned 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-mentioned 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 mounting 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, a plurality of blades are respectively connected to a blade fixing member with a virtual connecting line connecting one end located on the suction side and the other end located on the discharge side of the mounting side portion, and a driving electric motor. The angle between the axis of the output shaft and a virtual intersecting line formed on the outer peripheral surface of the blade fixing member intersecting the virtual surface including one end of the mounting side portion in the surface is 50 ° ± 2. It is attached to the blade fixing member at an angle of 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.

It is preferable to dispose a plurality of vanes inside the duct. Providing a plurality of vanes on the suction side or the discharge side of the cooling fan suppresses the generation of eddy currents on the suction side or the cooling side of the cooling fan and reduces noise. Conventionally, such a vane is generally provided in a cooling fan. In the present invention, since the stationary vanes are arranged inside the duct, compared with the case where the stationary vanes are provided in the cooling fan,
The axial dimension of the cooling fan can be shortened. As a result, there is an advantage that the axial dimension of the electric motor with the cooling fan can be shortened.

In the electric motor with a cooling fan, a pair of end brackets to which bearings supporting the output shaft are fixed are fixed to both ends of the stator core, and a plurality of cooling through holes through which cooling gas passes are formed in the stator core. And a rotation detector for detecting the rotation of the output shaft, the rotation detector for detecting the rotation of the output shaft is arranged outside the other end bracket located opposite to the one end bracket where the output shaft projects. A cooling fan that is provided on the outer side of the cooling fan and sucks the cooling gas through the plurality of cooling through holes, and a plurality of cooling through holes and a ventilation path of the cooling fan between the other end bracket and the outer surface of the rotation detector. And a duct forming a gas flow passage connecting the stationary vane and the outer surface of the other end bracket and the rotation detector with a slight gap. So as to open the preferably fixed to the inner wall of the duct.

It is preferable that the plurality of vanes provided in the duct be provided so as to divide the gas flow passage formed in the duct into a plurality of portions in the circumferential direction as much as possible. For that purpose, it is ideal that both ends of the stationary blade are fixed to or in contact with the inner wall portion of the duct and the outer surface of the end bracket and the rotation detector. However, unless the processing accuracy of the duct, end bracket, and cover of the rotation detector is increased, the stationary vane interferes and the assembly is not successful. Therefore, in the present invention, the stationary blade is fixed to the inner wall portion of the duct facing both the end bracket and the cover of the rotation detector, and a slight gap is provided between the stationary blade and the outer surface of the end bracket and the rotation detector. I did it. In this way, even if the vane is made as large as possible, the vane does not become an obstacle to assembly, and as a result, it is not necessary to make the processing accuracy of each part high.

The conventional stator core is formed by laminating a plurality of steel plates each having a through hole forming region in which a plurality of through holes forming cooling through holes are formed at each of four corners. However, it is preferable that a plurality of through holes forming cooling through holes are further formed in the intermediate region located between the two through hole forming regions in this steel plate. If you do this,
The temperature rise in the intermediate region can be suppressed, and the temperature rise of the device on the side where the electric motor is attached can be greatly suppressed.

The cooling fan used in the electric motor with a cooling fan according to the present invention has a stator core having a plurality of cooling through holes through which cooling gas passes, and is provided on the opposite side of the end portion of the output shaft of the electric motor main body. A cooling fan that is provided on the end side and applies pressure to the cooling gas that passes through the plurality of cooling through holes,
A plurality of blades, a blade fixing member to which the plurality of blades are fixed to the outer peripheral portion, a drive motor for rotating the blade fixing member, and a casing which surrounds the plurality of blades and forms a ventilation path inside , A plurality of webs connecting the driving electric motor and the casing. The outer peripheral surface of the outer peripheral portion of the blade fixing member has a shape inclined so that the diameter dimension increases from the suction side to the discharge side, and the sucked gas is guided in the axial direction of the output shaft of the drive motor. A plurality of blades are fixed to the outer peripheral portion so as to positively discharge in an oblique direction between the directions. And preferably, the outer peripheral portion of the blade fixing member is inclined so that the inclination angle between the blade fixing member and the axis of the output shaft of the driving electric motor is 35 ° ± 3.5 °, and the inner wall portion of the casing is The blade fixing member is inclined in the same direction as the outer peripheral surface of the outer peripheral portion of the blade fixing member, and is inclined so that the inclination angle with respect to the axis is smaller than the inclination angle of the outer peripheral surface.

[0022]

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 a cross-sectional view of an upper half portion of an electric motor, which has a cross section similar to the conventional example of FIG. 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 main 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 is constructed by winding a winding 11b around a stator iron 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 area 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 corner through holes 11e1 and 11e5 located at both ends have a triangular shape with rounded corners. The corner through holes 11e2 to 11e4, which are arranged between the corner through holes 11e1 and 11e5, have a longitudinal direction in the radial direction and a rectangular shape with rounded corners. Also in the intermediate region 12b between the two through hole forming regions 12a, the four intermediate through holes 11f1 to 11f4 forming the cooling through holes for passing the cooling gas through the stator core 11a are provided with the long side portion 1.
Are formed side by side along 1c. The intermediate through holes 11f1 and 11f4 located at both ends are
It has a rectangular shape with rounded corners. The intermediate through holes 11f2 and 11f3, which are arranged so as to be sandwiched between the intermediate through holes 11f1 and 11f4 on both sides, have a triangular shape with rounded corners. Corner through hole 11e1
˜11e5 and intermediate through holes 11f1 to 11f4
Has a shape and dimensions 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.
Are each formed with a plurality of cooling through holes 11i at each corner of the stator core 11a, and the middle half through holes 11f1 to 11f4 in the latter half of each half are used to cool a plurality of intermediate parts that are not conventional stator cores. Through holes 11j ... Are formed. In FIG. 1, the cooling through hole 1 located at the corner is shown.
Only 1i is 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 cooling gas suction port (11i1) is formed on the side of the cooling through hole 11i ... And the cooling through hole 11j ... where the shaft 7 protrudes (the side of the shaft portion 7a through which the output of the motor is taken out) (FIG. 1 shows only the suction port 11i1 of the cooling through hole 11i). According to the electric motor of the present embodiment, by providing the cooling through holes 11j located between the corners of the stator core 11a, compared with the conventional electric motor of the same type in which such a cooling through hole is not provided. It was confirmed that the temperature of the end bracket 13 could be lowered by about 5 degrees.

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 protrudes (on the side of the shaft portion 7a for extracting 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 and the gas flow passage 2
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. 3 is an enlarged cross section of the cooling fan 5 shown in FIG. 1, and FIG. 4 is a fan main body 27 viewed from the duct 3 side in FIG.
5 is a plan view of the blade fixing member 35 to which the blades 37 ... Are attached, and FIG. 5 is a plan view of the cooling fan 5 viewed from the right side (the discharge port 55 side) toward FIG. Here, both FIG. 4 and FIG. 5 depict not only the upper half but the entire upper and lower parts. Further, FIG. 5 is a plan view of the cooling fan 5 in which an upper half portion is removed with the fingered 57 attached to the frame body 53, and a lower half portion includes the fingered 57 attached to the frame body 53. It is a top view.

As shown in FIG. 3, the fan main 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. The inner cylindrical wall portion 45a constitutes a bearing holder, and bearings 49, 51 for rotatably supporting the shaft 39 are attached inside. 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. A labyrinth structure is formed by loosely fitting the cylindrical end portion 43b1 and the annular recess 45b1. The outer tubular wall portion 45c is
The end portion is arranged along the tubular end portion 35c of the blade fixing member 35 so as to form a slight gap with the tubular end portion 35c. A plurality of (four in this example) webs 31 are formed integrally with the motor bracket 45 on the outer peripheral portion of the outer cylindrical wall portion 45c. Also these webs 3
1 are integrally formed with an annular frame 53 connected to the casing 29 as shown in detail in FIG. As a result, the motor bracket 45 is supported by the frame body 53 via the webs 31. Frame 53 and motor bracket 4
The opening portion between the nozzle 5 and 5 forms a discharge port 55 through which a cooling gas for cooling the stator core 11a is discharged. And
A fingered 57 arranged outside the discharge port 55 is attached to the frame 53. Motor bracket 45
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. The stator 47 is configured 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 is from the suction side (the suction port 11i1 side) of the cooling gas to the discharge side (the discharge port 5).
It has a cylindrical shape or a trumpet shape that is inclined so that the diameter dimension increases toward the (5 side). Specifically, the outer peripheral surface of the blade fixing portion 35b has an inclination angle θ1 between the axis of the shaft 39 of the drive motor 33 and the outer peripheral surface of 35 °.
It is inclined so as to be within the angle range of ± 2 °. Since the shaft 39 of the driving electric motor 33 and the shaft 7 of the electric motor main body 1 share an axis line, the outer peripheral surface of the blade fixing portion 35b is 35 mm from the axis line of the shaft 7 of the electric motor main body 1.
It means that it is inclined at an angle of ± 2 °.

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 suction ports 11i1 of the plurality of cooling through-holes formed in the stator core 11a by the rotation of the blades 37 moves toward the discharge port 55 of the cooling fan in the axial direction of the shaft 39 of the drive motor 33. It is positively discharged obliquely between the radial directions. 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 its base (mounting side) is welded to the outer peripheral surface of the blade fixing portion 35b. It 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. Alternatively, the blades 37 may be formed of synthetic resin or the like and integrally formed with the blade fixing member 35. Each blade 37 has a shape such that a side 37b of the blade 37 opposite to the side 37a attached to the blade fixing portion 35 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 the two end portions 37c and 37d is shown as L1 in FIG. And the shaft 3 of the drive motor 33
9 axis and one end 37 of the attachment side 37a of the blade 37
A virtual intersection line (a line extending in the direction in which the cooling gas flows) L2 formed on the outer peripheral surface of the outer peripheral surface of the blade fixing portion 35b intersecting the virtual surface including c in the plane and the virtual connecting line described above. Each blade 37 is attached to the blade fixing portion 35 so that the angle θ3 with L1 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,
Also, the noise is close to the minimum. Outside this range,
The air volume decreases and the noise increases. 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.

The casing 29 comprises a frame side attachment portion (flange portion) 29a, a ventilation passage forming portion 29b, and a duct side attachment portion (flange portion) 29c. The frame-side mounting portion 29a and the duct-side mounting portion 29c each have an annular disc shape and extend in the radial direction of the shaft 39 of the drive motor 29, and are screwed to the frame body 53 and the duct 3, respectively. Will be stopped. Therefore, in these members, a plurality of through holes through which screws pass are formed at intervals in the circumferential direction. The air passage forming portion 29b is provided between the blade fixing member 35 and the blade fixing portion 35b, and has an annular air passage 59.
Has a cylindrical shape that forms Ventilation path forming part 29
The inner wall portion of b is inclined in the same direction as the outer peripheral portion of the blade fixing portion 35b is inclined. That is, the ventilation path forming unit 2
9b is from the duct side mounting portion 29c to the frame body side mounting portion 29a.
The diameter is enlarged so that the diameter becomes larger as it goes to.
The inclination angle θ2 between the inner wall portion of the ventilation passage forming portion 29b and the axis of the shaft 39 of the drive motor 33 is determined by the blade fixing portion 3
5b is inclined so as to be smaller than the inclination angle θ1 of the outer peripheral portion. In this example, this angle θ2 is 25 °.

FIG. 6 is a diagram schematically showing the relationship between the air flow rate and the air pressure of the mixed flow fan used as the cooling fan of the present embodiment and the axial flow fan and the centrifugal fan having substantially the same shape and size as the mixed flow fan. Is. In this figure, A to C indicate load curves. From this figure, it can be seen that the axial flow fan has a large air volume but a small air pressure. In addition, the centrifugal fan has a large air pressure but a small air volume. On the other hand, the mixed flow fan has characteristics intermediate between those of the axial flow fan and the centrifugal fan. As a result, it can be seen that, at any intersection of the load curves A to C, the mixed flow fan has a larger air volume and pressure than the axial flow fan and the centrifugal fan.

FIG. 7 is a half sectional view of an electric motor with a cooling fan according to another embodiment of the present invention. In this figure, the same parts as in FIG.
Is added and the description thereof is omitted. In the embodiment shown in this figure, a structure that flows in the stator core 111a side from the cooling fan 105 side as shown in the cooling gas arrow B to cool the stator core 111a opposite to the arrow A shown in FIG. 1 Have That is, in the embodiment shown in this figure,
The portion corresponding to the suction port shown in FIG. 1 is the discharge port 111i1.
And the portion corresponding to the discharge port shown in FIG. 1 is the suction port 1.
55. In order to configure in this way, the cooling fan 105 from which the fingered 157 is removed is inverted and attached to the duct 103, and the casing 129 and the blade fixing member 135 are tilted in the same direction as the reduced diameter tubular portion 103b of the duct 103. Good. Then, the frame body 153 is screwed to the duct 103, and the fingered 157 is attached to the fingered attachment portion 129c (a portion corresponding to the duct side attachment portion 29c in FIG. 3).

[0042]

According to the present invention, by using a mixed flow 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. As a result, the cooling fan can be downsized, the axial dimension of the electric motor with the cooling fan can be reduced, and noise can be reduced.

[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 air pressure of the mixed flow fan used as the cooling fan of the present embodiment and the conventionally used axial flow fan and centrifugal fan.

FIG. 7 is a half sectional view of an electric motor with a cooling fan according to another embodiment of the present invention.

FIG. 8 is a half sectional view of a conventional electric motor with a cooling fan.

[Explanation of symbols]

1 Electric motor body 3 ducts 5 cooling fan 7 shaft (output shaft) 11a Stator core 11e1 to 11e5 corner through holes 11f1 to 11f4 intermediate through hole 11i ... Cooling through hole 11j ... Cooling through hole 13,15 End bracket 17 Rotation detector 29 casing 31 ... Web 33 Drive motor 35 blade fixing member 37 ... feather 39 Shaft (output shaft)

─────────────────────────────────────────────────── ─── 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-9-154256 (JP, A) JP-A-7-119685 (JP, A) JP-A-7-245915 (JP, A) JP-A-55-160952 (JP, A) JP-A-55-51995 (JP, A) JP 63-310340 (JP, A) Actually opened 63-202154 (JP, U) Actually opened 64-11397 (JP, U) Actually opened 63-48365 (JP, U) Actual KAISHO 59-78848 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) H02K 9/00-9/28 H02K 1/20 F04D 17/00-23/00 F04D 29/18 -29/70

Claims (9)

(57) [Claims] 1. An electric motor body having a plurality of cooling through-holes, through which cooling gas passes, formed in a stator iron core, and the electric motor body is provided on an end portion side opposite to an end portion from which an output shaft projects. A cooling fan that applies pressure to the cooling gas that passes through the plurality of cooling through holes, and a duct that forms a gas flow passage that connects the plurality of cooling through holes and the ventilation path of the cooling fan. The cooling fan comprises a plurality of blades, a blade fixing member to which the plurality of blades are fixed to an outer peripheral portion, a driving electric motor for rotating the blade fixing member, and a periphery of the plurality of blades. An electric motor with a cooling fan, comprising: a casing that forms the ventilation passage inside the enclosure; and a plurality of webs that connect the driving electric motor and the casing, wherein the cooling fan is a suction fan For driving Configured diagonal flow fan is used to discharge actively diagonally between the axial and radial direction of the output shaft of motivation, the outer peripheral portion of the blade fixing member of the driving electric motor
An inclination angle between the axis of the output shaft and 30 ° to 45 °
The outer wall of the outer peripheral portion of the inner wall of the casing is inclined so that the inner wall of the casing is inclined.
Angle inclining in the same direction as the
So that the degree is smaller than the inclination angle of the outer peripheral surface.
An electric motor with a cooling fan characterized by being inclined. 2. A bearing for supporting the output shaft is fixed.
A pair of end brackets are attached to both ends of the stator core.
A plurality of cooling holes through which cooling gas passes through the stator core.
One of the above-mentioned
The other end located opposite to the end bracket
A rotation detector that detects the rotation of the output shaft on the outside of the bracket.
The electric motor main body in which the output device is arranged and the front of the electric motor main body provided outside the rotation detector.
Intake the cooling gas through a plurality of cooling through holes.
Cooling fan, and the outer surface of the other end bracket and the rotation detector
Passing said cooling fan and said plurality of cold 却用through hole between the
A duct forming a gas flow passage connecting to the air passage
And, the cooling fan, and a plurality of blades, fixed to the rotor
Blades fixed to the outer periphery of the ring.
A constant member, a driving electric motor for rotating the rotor,
The ventilation passage is formed inside by surrounding a plurality of blades.
A tubular casing, the drive motor and the case
Cooling web having a plurality of webs for joining
A fan-equipped electric motor, wherein the cooling fan is the outer peripheral portion of the blade fixing member.
The outer peripheral surface of the has a large radial dimension from the suction side to the discharge side.
It has a slanted shape so that the sucked gas is
Diagonal between the axial direction and the radial direction of the output shaft of the electric motor
The plurality of blades to positively discharge in the direction
A mixed flow fan fixed to the outer peripheral portion is used, and the outer peripheral surface of the outer peripheral portion of the blade fixing member is the drive member.
The inclination angle between the axis of the output shaft of the electric motor is 30.
The casing is inclined so as to form an angle of 45 °, and the inner wall portion of the casing has a direction in which the outer peripheral surface is inclined.
Inclined in the same direction and the angle of inclination with the axis is
Inclining so that it is smaller than the inclination angle of the outer peripheral surface
An electric motor with a cooling fan. 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 battery with a cooling fan according to claim 1 or 2,
Motive. 4. The plurality of blades are respectively the blades.
Located on the suction side of the mounting side that is attached to the root fixing member.
One end to be placed and the other end located on the discharge side
And a virtual connecting line connecting the output motor of the drive motor
Temporary inclusion of the axis and the one end of the mounting side in the plane
The outer peripheral surface of the blade fixing member intersects with the outer peripheral surface of the blade fixing member.
The angle between the virtual intersection line formed on the
Of the 7 sheets attached to the wing fixing member
The cooling fan according to claim 3, wherein the cooling fan is composed of vanes.
Electric motor with fan. 5. A plurality of stationary vanes are arranged inside the duct.
With a cooling fan according to claim 1 or 2 installed
Electric motor. 6. The plurality of stationary vanes are provided at the other end.
Slightly between the bracket and the outer surface of the rotation detector
Fixed to the inner wall of the duct with a large gap.
The electric motor with a cooling fan according to claim 5, 7. The stator core has four corner portions, respectively.
A plurality of through holes forming the cooling through holes are formed in
Constructed by stacking multiple steel plates with through-hole forming areas
It is, above the steel plate located between two of the through-hole forming region
A plurality of through holes that further form the cooling through holes in the intermediate region
The cooling fan according to claim 1 or 2, wherein holes are formed.
Electric motor with 8. A plurality of coolers through which a cooling gas passes through a stator core.
The output shaft of the electric motor body with the through hole for ejection projects
Is provided on the side of the end opposite to the end for cooling the plurality of
With a cooling fan that sucks the cooling gas through the through hole
There are multiple blades and the multiple blades are fixed to the outer peripheral part.
Blade fixing member and drive for rotating the blade fixing member
For the electric motor and surrounding the plurality of blades
A casing forming an air passage, the drive motor and the front
A plurality of webs for connecting with the casing, and the outer peripheral surface of the outer peripheral portion of the blade fixing member is discharged from the suction side.
A shape that is inclined so that the diameter dimension increases toward the exit side
The suctioned gas is directed toward the axis of the output shaft of the drive motor.
Before the positive discharge in the diagonal direction between the direction and the radial direction
Serial plurality of blades is fixed to the outer peripheral portion, the vane solid
The outer peripheral surface of the outer peripheral portion of the fixed member is the drive motor.
The inclination angle between the output shaft and the axis of the output shaft is 35 ° ± 3.5.
Is inclined so that the inner wall portion of the casing is the outer periphery of the blade fixing member.
The surface is inclined in the same direction as the direction in which it is inclined and
The inclination angle between the two is smaller than the inclination angle of the outer peripheral portion.
Inclination so that
Hmm. 9. The plurality of blades are respectively the blades.
Located on the suction side of the mounting side that is attached to the root fixing member.
One end to be placed and the other end located on the discharge side
And a virtual connecting line connecting the output motor of the drive motor
Temporary inclusion of the axis and the one end of the mounting side in the plane
The outer peripheral surface I virtual plane Majiwa and the outer peripheral surface of the blade fixing member
The angle between the virtual intersection line formed on the
Of the 7 sheets attached to the wing fixing member
The cooling fan according to claim 8, wherein the cooling fan is composed of vanes.
Hmm.