JP7381298B2 - air cooled electric motor - Google Patents

Description

The present invention relates to an air-cooled electric motor.

Air-cooling systems are often used to cool the motor bodies of motors used in machine tool spindles and the like. In such an air-cooled electric motor, a cooling fan is installed at the rear of the electric motor so that the cooling air exhaust direction is parallel to the axial direction of the electric motor, and a partition plate is installed inside the electric motor to rectify the airflow caused by the cooling fan. is common. An example of a configuration in which a partition plate is provided within a fan cover of a cooling device for an electric motor is described in, for example, Patent Document 1.

Japanese Patent Application Publication No. 2005-278287

Since the partition plate is generally made of a plate-shaped member, if the partition plate is not sufficiently restrained within the motor, vibrations from the motor body or the fan motor will be transmitted to the partition plate, causing the partition plate to vibrate, causing damage to the motor such as the fan cover. There is a risk that the product may come into contact with the outer wall of the product and generate vibration noise. An air-cooled electric motor is desired that can securely restrain the partition plate to the outer wall of the electric motor and prevent the generation of vibration noise.

One aspect of the present disclosure is an air-cooled electric motor that includes a cooling fan for cooling the electric motor body, a partition plate that rectifies the airflow within the air-cooled electric motor by the cooling fan, and houses the electric motor body. a fan cover attached to a motor housing and accommodating the cooling fan, the partition plate being formed of a plate-like member, and allowing the airflow by the cooling fan to pass through a central portion of the plate-like member. The fan cover has an opening and an inclined portion inclined with respect to the radial direction on a radially outer peripheral edge perpendicular to the axial direction of the motor main body when disposed in the air-cooled electric motor. constitutes a part of the outer wall of the air-cooled electric motor, and an inclined surface inclined with respect to the axial direction is formed on the inner wall surface of the fan cover, and the partition plate forms a part of the outer wall of the air-cooled electric motor. The fan cover is fixed to the fan cover at a portion radially inner than the inclined portion, and the inclined portion is restrained to the inclined surface in both the axial direction and the radial direction. This is an air-cooled electric motor that is in close surface contact with an inclined surface .

According to the above configuration, it is possible to reliably restrain the partition plate to the outer wall of the electric motor and prevent the generation of vibration noise.

These and other objects, features and advantages of the invention will become more apparent from the detailed description of exemplary embodiments of the invention, which are illustrated in the accompanying drawings.

FIG. 1 is an axial cross-sectional view showing the configuration of an electric motor according to an embodiment. 2 is an enlarged view of a rectangular area indicated by a broken line in FIG. 1. FIG. It is a perspective view of a partition plate. FIG. 3 is a front view of the partition plate as seen from the front side. FIG. 5 is a cross-sectional view of the partition plate as seen in the direction of arrow A in FIG. 4. FIG. It is a perspective view of a fan cover. FIG. 3 is a front view of the fan cover as seen from the front side. 8 is a sectional view of the fan cover taken in the direction of arrow A in FIG. 7. FIG. FIG. 3 is an axial cross-sectional view showing another configuration example of the electric motor according to the present embodiment. FIG. 3 is an axial cross-sectional view showing the configuration of an electric motor of a comparative example.

Next, embodiments of the present disclosure will be described with reference to the drawings. In the drawings referred to, like components or functional parts are provided with like reference numerals. For ease of understanding, the scale of these drawings has been changed accordingly. Moreover, the form shown in the drawings is one example for implementing the present invention, and the present invention is not limited to the form shown in the drawings.

FIG. 1 is an axial cross-sectional view showing the configuration of an air-cooled electric motor 10 (hereinafter referred to as electric motor 10) according to an embodiment. In the following, for convenience of explanation, as shown in FIG. 1, the output shaft side in the axial direction will be referred to as the front side, and the side opposite to the output shaft (the side where the cooling fan 20 is located) will be referred to as the rear side. Further, a direction perpendicular to the axial direction of the output shaft 1 is also referred to as a radial direction. The electric motor 10 is air-cooled and includes a motor main body 2 , a peripheral wall-shaped motor housing 3 surrounding the motor main body 2 , and a cooling fan 20 disposed at the rear end of the motor housing 3 . The cooling fan 20 is housed in a fan cover 30, and the front end of the fan cover 30 is attached to the rear end of the motor housing 3. The motor housing 3 and the fan cover 30 constitute an outer wall portion of the motor 10. At least one vent hole 6 is formed between the motor body 2 and the inner circumferential surface of the motor housing 3, through which airflow from the cooling fan 20 passes. The ventilation holes 6 extend parallel to the axial direction of the output shaft 1 of the electric motor 10, and in a cross-sectional view perpendicular to the axial direction, for example, when the electric motor housing 3 is rectangular, the ventilation holes 6 are provided at four corners. Alternatively, it may be formed all around the motor body 2.

A fan motor 21 is attached to the rear end inside the fan cover 30. A partition plate 50 is attached to the front end portion of the fan cover 30 to rectify the airflow from the ventilation holes 6 (see arrows in FIG. 1) and guide it to the cooling fan 20. Details of the partition plate 50 and fan cover 30 will be described below. FIG. 2 is an enlarged view of region F indicated by the broken line in FIG. 3, FIG. 4, and FIG. 5 are a perspective view of the partition plate 50, a front view seen from the front side, and a sectional view in the direction of arrow A in FIG. 4, respectively. 6, 7, and 8 are a perspective view of the fan cover 30, a front view seen from the front side, and a sectional view taken in the direction of arrow A in FIG. 7, respectively.

As shown in FIGS. 6 to 8, the fan cover 30 has an octagonal outer shape when viewed along the axial direction, and is located on the front end side of a cylindrical fan motor accommodating portion 32 that accommodates the fan motor 21. The opening is shaped like a bell mouth, widening toward the front. More specifically, as shown in FIG. 2, an inclined wall 31 is formed from the front end of the fan motor accommodating portion 32 and is inclined with respect to the axial direction so as to spread outward in the radial direction toward the front. A peripheral wall 33 is formed from the front end of 31 and extends forward in the axial direction.

As shown in FIGS. 3 to 5, the partition plate 50 is a plate-shaped member having an octagonal outer diameter shape when viewed along the axial direction, and allows air flow by the cooling fan 20 to pass through the central part. It has a circular opening 52. A sloping portion 51 that slopes forward in the radial direction is formed at the peripheral edge of the partition plate 50 . As shown in FIGS. 3 and 4, screw holes 54 are formed at four locations around the periphery of the partition plate 50, and as shown in FIG. It is fixed with screws from the front side into four screw holes 34 (see Figure 6-7). When the partition plate 50 is screwed and fixed from the front side, the inclined portion 51 at the peripheral edge of the partition plate 50 comes into close surface contact with the inclined wall 31 on the fan cover 30 side (see FIG. 2). .

The left side of FIG. 2 shows an enlarged view of a close contact area between the inclined portion 51 of the partition plate 50 and the inclined wall 31 of the fan cover 30 (the area surrounded by a circle with a broken line). The fan cover 30 is provided with an inclined wall 31 that is inclined with respect to the axial direction, and the partition plate 50 is provided with an inclined part 51 that is inclined with respect to the radial direction on the peripheral edge of the partition plate 50, so that the partition plate 50 is screwed to the fan cover 30. In the fixed state, the inclined portion 51 can be pressed against the inclined wall 31 in both the axial direction and the radial direction. In this state, the outer circumferential surface 51a of the inclined portion 51 and the inclined surface 31a on the inner circumferential surface side of the inclined wall 31 are in close contact with each other over the entire circumference. As can be seen from FIG. 2, the inclined wall 31 (inclined surface 31a) of the fan cover 30 has a shape that is sufficiently wide compared to the inclined part 51 (outer peripheral surface 51a) of the partition plate 50, and the outermost part of the inclined part 51 A sufficient distance is ensured between the end face of the frame and the peripheral wall 33.

According to such a configuration, even when vibrations from the fan motor 21 or the electric motor main body 2 are transmitted to the partition plate 50 and the partition plate 50 vibrates in the axial direction and the direction perpendicular to the axial direction, the peripheral edge of the partition plate 50 This prevents vibration noise from hitting the inner wall surface of the fan cover 30 and generating vibration noise. In particular, according to the above configuration, it is possible to press the inclined portion 51 of the partition plate 50 against the inclined wall 31 in both the axial direction and the radial direction, so that the peripheral edge of the partition plate 50 can be pressed against the inclined wall 31 in both the axial and radial directions. It becomes possible to sufficiently restrain both sides.

Furthermore, according to the above configuration, it is possible to reliably bring the peripheral edge of the partition plate 50 into close contact with the inner circumferential surface of the fan cover 30, thereby ensuring that air leakage from the peripheral edge of the partition plate 50 is prevented. It becomes possible to prevent this, and thereby it becomes possible to improve cooling efficiency. The inclination angle a of the inclined wall 31 of the fan cover 30 with respect to the axial direction may be, for example, 45 degrees, or may be another angle.

Here, as a comparative example, a configuration of an electric motor in which the fan cover does not have an inclined wall and the partition plate does not have an inclined part will be described. FIG. 10 is an axial cross-sectional view schematically showing the configuration of an electric motor 200 as such a comparative example. As shown in FIG. 10, the electric motor 200 of the comparative example has a configuration in which a fan cover 230 that accommodates a cooling fan 220 is attached to the rear end side of the electric motor body, similar to the electric motor 10 according to the above-described embodiment. . A partition plate 250 is fixed to the front side of the fan cover 230 with screws. A peripheral portion of the partition plate 250 is formed to extend along the radial direction. That is, the peripheral edge of the partition plate 250 does not have an inclined portion that is inclined with respect to the radial direction. A protrusion 231 that protrudes toward the central axis of the motor body is formed on the front inner wall surface of the fan cover 230. The protrusion 231 is formed over the entire circumference of the inner wall surface of the fan cover 230 in a radial cross-sectional view seen from the axial direction, and in the axial cross-sectional view of FIG. It is formed into a vertical rectangular shape.

Considering the dimensional error of the fan cover 230, the dimensions of the partition plate 250 are set so that a gap is secured between the end face of the peripheral edge of the partition plate 250 and the inner wall surface of the fan cover 230 as shown in FIG. is set. The protrusion 231 plays a role in closing this gap. In the above configuration, the partition plate 250 is screwed and fixed to the fan cover 230 so that its peripheral edge contacts the front side surface 231a of the protrusion 231. There are four screw-fastening locations as in the case of the partition plate 50 of the above-described embodiment. In the configuration shown in FIG. 10, the peripheral edge of the partition plate 250 is not sufficiently constrained in the radial direction perpendicular to the axial direction, so vibrations of the partition plate 250 caused by vibrations of the electric motor body or the fan motor may cause the peripheral edge of the partition plate 250 to When the fan cover 230 hits the inner wall surface of the fan cover 230, vibration noise may be generated.

In addition, in the configuration of FIG. 10, particularly in the area between the screw-fastening locations of the partition plate 250 and the fan cover 230 in the circumferential direction, air leakage is caused due to insufficient restraint of the partition plate 250 to the fan cover 230. Leaks may also occur.

Therefore, it can be seen that the configuration of the electric motor 10 according to the embodiment described above is advantageous in terms of prevention of vibration noise and cooling efficiency compared to the electric motor 200 of the comparative example of FIG. 10.

Next, a modification of the electric motor 10 according to the above embodiment will be described. FIG. 9 is an axial cross-sectional view schematically showing the configuration of an electric motor 10A as a modification of the electric motor 10. As shown in FIG. As shown in FIG. 9, the electric motor 10A has a configuration in which a fan cover 130 that accommodates a cooling fan 120 is attached to the rear end side of the electric motor body, similar to the electric motor 10 according to the above-described embodiment. A partition plate 150 is fixed to the front side of the fan cover 130 with screws. The partition plate 150 has the same configuration as the partition plate 50, and the peripheral edge of the partition plate 150 is formed as an inclined portion 151 inclined with respect to the radial direction. Taking into account dimensional errors of the fan cover 130, a gap is ensured between the peripheral end face of the partition plate 150 (the outermost end face in the radial direction) and the inner wall surface of the fan cover 130, as shown in FIG. The dimensions of the partition plate 150 are set as follows.

A protrusion 131 that protrudes toward the central axis is formed on the inner peripheral surface of the front side of the fan cover 130 . The protrusion 131 is formed over the entire inner circumference of the fan cover 130 in a radial cross-sectional view viewed from the axial direction, and is formed in a triangular shape in an axial cross-sectional view in FIG. It is formed as an inclined surface 131a that is inclined with respect to the surface.

With this configuration, similarly to the case of the electric motor 10 described above, when the partition plate 150 is screwed and fixed to the fan cover 130, the inclined portion 151 is pressed against the inclined surface 131a in both the axial direction and the radial direction. It can be done. In this state, the inclined portion 151 and the inclined surface 131a are in close contact with each other over the entire circumference. According to such a configuration, in a situation where vibrations from the fan motor 121 or the electric motor main body are transmitted to the partition plate 150 and the partition plate 150 vibrates, the peripheral edge of the partition plate 150 hits the inner wall surface of the fan cover 130 and vibration noise is generated. It is prevented from doing so. In particular, according to the above configuration, the inclined portion 151 of the partition plate 150 can be pressed against the inclined surface 131a in both the axial direction and the radial direction, so that the peripheral edge of the partition plate 150 can be pressed against the inclined surface 131a in both the axial and radial directions. It becomes possible to sufficiently restrain both sides.

As described above, according to the present embodiment, it is possible to reliably restrain the partition plate to the outer wall of the electric motor and prevent the generation of vibration noise.

Although the present invention has been described above using typical embodiments, those skilled in the art will be able to make changes to each of the above-described embodiments and various other changes, omissions, and modifications without departing from the scope of the present invention. It will be appreciated that additions can be made.

The configuration of the electric motor shown in the above-described embodiments is merely an example, and the present invention is not limited thereto. For example, in the above-described embodiment, the partition plate 50 and the fan cover 30 have an octagonal outer shape when viewed along the axial direction, but may have another shape (for example, a circular shape). Further, the number of screwing locations between the partition plate and the fan cover may be other than four. Fixing means other than screws may be used to fix the partition plate to the fan cover. The material of the partition plate is, for example, metal, but other materials (for example, resin) may also be used.

An inclined part inclined with respect to the radial direction is formed on the peripheral edge of the partition plate, an inclined surface inclined with respect to the axial direction is formed on the inner side of the outer wall of the electric motor, and these inclined parts and the inclined surface are brought into surface contact. The configuration of the above-described embodiment can be applied to various types of air-cooled electric motors.

10, 10A Air-cooled electric motor 1 Output shaft 2 Motor body 3 Motor housing 6 Ventilation hole 20, 120 Cooling fan 30, 130 Fan cover 31 Inclined wall 31a, 131a Inclined surface 50, 150 Partition plate 51, 151 Inclined part 52 Opening 131 protrusion

Claims (2)

An air-cooled electric motor,
A cooling fan for cooling the electric motor body,
a partition plate that rectifies the airflow within the air-cooled electric motor caused by the cooling fan;
a fan cover that is attached to a motor housing that accommodates the motor main body and that accommodates the cooling fan;
The partition plate is formed of a plate-shaped member, and has an opening in the center of the plate-shaped member through which airflow from the cooling fan passes, and when placed in the air-cooled electric motor, the partition plate is formed of a plate-shaped member. A radially outer peripheral edge perpendicular to the axial direction of the main body has an inclined part inclined with respect to the radial direction,
The fan cover constitutes a part of an outer wall portion of the air-cooled electric motor, and an inclined surface inclined with respect to the axial direction is formed on an inner wall surface of the fan cover,
The partition plate is fixed to the fan cover at a peripheral portion of the plate-shaped member that is radially inner than the inclined portion, and the inclined portion is fixed to the fan cover in both the axial direction and the radial direction. in close surface contact with the inclined surface so as to be restrained with respect to the inclined surface;
Air-cooled electric motor. 2. The air-cooled electric motor according to claim 1, wherein a protrusion protruding toward the central axis of the motor body is formed on the inner wall surface , and the inclined surface is formed on the protrusion.

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