JPH0428203Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a bearing cooling device for an electric motor, and more particularly to a cooling device for cooling a bearing that supports an output shaft of an electric motor.

BACKGROUND ART FIG. 7 is a simplified cross-sectional view of a prior art electric motor 1. A stator coil 3 is provided within a frame 2 of the electric motor 1 . A rotor 5 is fixed to an output shaft 4 at a position facing the stator coil 3.

Both ends of the output shaft 4 protrude outward from the bracket 12 and are supported by bearings 6 and 7, respectively, so as to be rotatable around an axis. The output shaft 4 protrudes outward from the axis 6 on the side opposite to the load side of the electric motor 1.
A plurality of blades 8 are arranged at intervals in the circumferential direction. The manner in which the blades 8 are attached is such that when the output shaft 4 is rotationally driven to drive a load (not shown), air is directed toward the frame 2 side (right side in FIG. 7), that is, in the direction of arrow A1. configured so that it can be sent. In addition, a cover 9 surrounding this blade 8
is provided, and air from an intake port 10 formed in the cover 9 is sent to the frame 2 side by the vane 8, and this air flow is transferred by the cover 9 to the frame 2 side.
It is sent to the right in Fig. 7 along.

In such a prior art electric motor 1, the airflow does not sufficiently contact the bearing 7, which may cause the bearing 7 to burn out.

Furthermore, the grease used to lubricate the bearings 6 and 7 does not necessarily have excellent heat resistance, and therefore it has been difficult to improve the allowable temperature during operation of the electric motor 1. Also, electric motor 1
Even if high-quality winding materials with excellent heat resistance are used, unless the heat resistance of the bearings 6 and 7 is improved,
There was a problem that the electric motor 1 could not exhibit sufficient performance.

FIG. 8 is a cross-sectional view of another prior art. This prior art is similar to the prior art described above, and corresponding parts are given the same reference numerals. In addition to the configuration shown in FIG. 7, this prior art provides a cover 11 that covers the vicinity of the bearing 7 to cool the bearing 7 sufficiently.
That is, the direction of the air flow sent along the outer circumferential surface of the frame 2 by the vanes 8 is changed by the cover 11, and the air is sent to the vicinity of the bearing 7. Although the electric motor 1 of the prior art solves the problem that the bearing 7 is not sufficiently cooled as described in the prior art, dust accumulates on the bearing 7 and the bearing 7 heat dissipation is inhibited. Moreover, the cover 11 causes turbulence in the airflow along the frame 2, resulting in the generation of high temperature portions in the frame 2, which is another problem.

Problems to be Solved by the Invention The purpose of the invention is to solve the above-mentioned problems, to efficiently cool the bearing that supports the output shaft of the electric motor, and to prevent dust, etc. from being removed from the bearing being cooled. It is an object of the present invention to provide a bearing cooling device for an electric motor that can prevent deposition.

Means for Solving the Problems The present invention provides cooling fins 29 formed on the frame 16 with first cooling fins fixed to one end of the output shaft 19.
In a bearing cooling device for a fully enclosed external fan-shaped electric motor in which air intake by blades 22 is guided by a cover 23, the bearing cooling device is fixed to the other end of the output shaft 19 and is attached to the frame 16.
a second blade 26a that sends air to the side and has a smaller outer diameter than the first blade 22; and a second blade 26a coaxially with the frame 16;
It has a smaller diameter than the frame 16, has an intake port on the opposite side to the frame 16, is provided axially away from the frame 16, and directs air by the second blade 26a radially inward as it approaches the frame 16. This is a bearing cooling device for an electric motor characterized in that it includes a truncated cone-shaped cover member 46 that leads to a truncated cone shape.

Effect According to the present invention, the second blade 22 and the second blade 26a are fixed to both ends of the output shaft 19 respectively protruding from the frame 16 of the electric motor 15, and these first and second blades 2 feathers 2
The air from 2 and 26a is sent to the frame 16 side, and therefore the frame 1 supporting the output shaft 19
The bearings 20 and 21 provided in the bearings 6 can be efficiently cooled, and dust and the like can be prevented from accumulating on the bearings to be cooled.

Moreover, the air from the first blade 22 is removed from the cover 22.
Since it is guided toward the cooling fins 29 through the cooling fins 29, the frame 16 can be efficiently cooled.

Further, the air from the second vane 26a is guided by a cover member 46, which includes:
It is provided apart from the frame 16 in the axial direction, has a truncated conical shape, and has a smaller diameter than the frame 16, so that the air from the first blade 22 cooling the cooling fin 29 is not disturbed.
The bearing of the other end of the output shaft 19 to which the second blade 26a is fixed can be reliably cooled.

In particular, according to the present invention, the load side of a totally enclosed fan motor, which is equipped with the first blade 22 at one end of the output shaft 19 and has no blades at the other end of the output shaft 19, that is, the output A second blade having an outer diameter smaller than that of the first blade 22 is provided at the other end of the shaft 19.
While fixing the blade 26a, the second blade 2
A cover member 46 is provided to cover the output shaft 19, thereby cooling the bearing on the other end side of the output shaft 19.

Moreover, according to the present invention, as described above, the second blade 26a has a smaller outer diameter than the first blade 22, so that the cooling air flow between the first blade 22 and the second blade 26a is reduced. In particular, the second
The blade 26a allows the bearing at the other end of the output shaft 19 to be cooled.

Embodiment FIG. 1 is a partially sectional front view of an electric motor 15 showing the basic configuration of the present invention. Electric motor 15
A stator coil 17 is disposed within the frame 16 . An output shaft 19 to which a rotor 18 is fixed is provided at a position facing the stator coil 17. Both ends of the output shaft 19 protrude outward from the frame 16 and are supported by bearings 20 and 21 so as to be rotatable about their axes.

One rear end of the output shaft 19 further protrudes from the bearing 20 in the axial direction, and a plurality of first blades 22 are fixed at intervals in the circumferential direction. When the output shaft 19 is rotationally driven to drive a load (not shown) by the electric motor 15, the first blade 22 is axially moved toward the frame 16 side, that is, toward the right side in FIG. It has a shape and configuration that allows air to flow through it. A cover 23 having a generally cylindrical shape and coaxial with the frame 16 is disposed to cover the first blade 22 . An intake port 25 is formed at an end 24 of the cover 23 on the opposite side from the frame 16. Further, at the end of the frame 16 on the first blade 22 side, a bracket 27a is connected to the bearing 20 and the first blade 22.
It is provided between the blade 22 and fixed to the frame 16.

The other end of the output shaft 19 protrudes further outward in the axial direction than the bearing 21, and a plurality of second blades 26 are fixed at intervals in the circumferential direction. frame 1
A bracket 27 is attached to the end of the blade 6 on the second blade 26 side.
b is provided between the bearing 21 and the second blade 26,
It is fixed to the frame 16. This second blade 26
is an axial flow blade. Also, the outer side of the frame 16 in the radial direction is in contact with the cooling fins 29 and the cover 2
The end portion 23a of 3 extends.

The frame 16 of the electric motor 15 is fixed on a base 28, and a large number of cooling fins 29 are attached to the frame 16, which protrudes radially outward along the axial direction. A terminal box 30 is provided on the outer periphery of the frame 16, and a grip portion 31 is provided at the top for carrying the electric motor 15.

2 is a left side view of FIG. 1, and FIG. 3 is a sectional view taken along the cutting plane line - of FIG. 1. A wire mesh 32 is attached to the intake port 25 of the end portion 24 of the cover 23.

FIG. 4 is a perspective view of the second blade 26 of FIG. 1. A right cylindrical boss 33 is attached to the output shaft 19 so as to fit almost snugly into the output shaft 19 . The boss 33 has a radial axis, passes through the boss 33 in the radial direction, and has, for example, three screw holes 34 formed with internal threads at intervals in the circumferential direction. The boss 33 is fixed to the output shaft 19 by screwing a bolt 35 into each screw hole 34 and pressing the output shaft 19 with the tip 36 of the bolt 35.

As described above, a plurality of bosses (four in this configuration) are arranged at intervals in the circumferential direction on the outer periphery of this boss 33.
The second blade 26 of is fixed. The shape of these second blades 26 and the manner in which they are attached to the boss 33 are such that when the output shaft 19 is rotationally driven in the direction of arrow B1, for example, the second blades 26 rotate in the opposite direction from the frame 16 (see FIG. 1), that is, in the direction of the arrow B1. It is set to send air in the direction of mark B2. That is, with respect to the virtual plane 38 perpendicular to the axis 37 of the boss 33, each of the flat second blades 26
is installed so as to be inclined by a predetermined angle θ1 in the direction of arrow B2 toward the upstream side in the direction of arrow B1.

Referring again to FIG. 1, such an electric motor 15
When the output shaft 19 is rotationally driven, for example, in the direction of the arrow B1, the first blade 22 causes the output shaft 19 to rotate in the direction of the arrow B1.
Airflow occurs in three directions. This airflow impinges on the bracket 27a of the frame 16 and cools the bearing 20 via the bracket 27a. Further, this air flow flows in the direction of arrow B4, and the first
Reach the right-hand edge of the diagram.

On the other hand, the second vane 26 generates an airflow in the direction of arrow B2. This airflow can flow radially inwardly along the bracket 27b and thus cool the bearing 21 via the bracket 27b. On the other hand, since the airflow in the direction of arrow B2 is generated, the airflow in the direction of arrow B4 generated by the first blade 22 is localized near the right end of the electric motor 15 in FIG. It is possible to prevent the frame 16 or the bracket 27b from becoming partially stagnant and having a high temperature area.

FIG. 5 is a sectional view of an embodiment of the present invention. This embodiment is similar to the previously described configuration, and corresponding parts are given the same reference numerals. The load side (right side in FIG. 5) of the output shaft 19 is fixed to one boss 40 of a so-called flexible shaft joint 39, and the second blade 26a is fixed to this boss 40.

Such a flexible shaft joint 39 includes a pair of bosses 40, 41, and disk-shaped flanges 42, 43 fixed coaxially with each boss 40, 41.
Boss 40 and flange 42 constitute joint part 44, and boss 41 and flange 43 constitute joint part 4.
form 5. Each of these joint parts 44, 45
are each integrally formed from a metal material.
In addition, an elastic member (not shown) is sandwiched between the flanges 42 and 43 to realize a so-called flexible shaft joint 39.

The second blade 26a is configured to generate an airflow in the direction of arrow B5 when the output shaft 19 is rotationally driven in the direction of arrow B1, contrary to the above-described configuration. This second blade 26a is formed smaller than the first blade 22. Therefore, the airflow in the direction of arrow B4 caused by the first blade 22 is not disturbed by the airflow in the direction of arrow B5 generated by the rotational drive of the second blade 26a. A cover member 46 is provided to cover the second blade 26a.

FIG. 6 is a perspective view of the cover member 46 of FIG. 5. The cover member 46 includes an upper cover 47 and a lower cover 48, and the lower cover 48 is fixed to a mounting base 49. Moreover, the upper cover 47 and the lower cover 48 are
They are flanged together.

With reference to FIGS. 5 and 6, cover member 4
The upper cover 47 and the lower cover 48 of 6 are bottomless and topless, and the radius decreases from the front side in the axial direction (right side in FIG. 5) to the rear side in the axial direction (left side in FIG. 5). It forms a truncated cone shape. First blade 2
2 has approximately the same outer diameter as the frame 16.
The cover 23 removes the air from the first blade 22,
It is guided in the axial direction toward the cooling fins 29 of the frame 16. The second blade 26a sends air to the frame 16 side and has a smaller outer diameter than the first blade 22. The cover member 46 covers the second blade 26a coaxially with the frame 16 and has a smaller diameter than the frame 16. This cover member 46 has an air intake port on the opposite side to the frame 16 (on the right side in FIG. 5), and is provided away from the frame 16 in the axial direction by the reference numeral d in FIG. 5. This cover member 46 covers the frame 1
6 (toward the left in FIG. 5), the second blade 26a is guided inward in the radial direction, so that the second blade 26a is shaped like a truncated cone as described above.

The second blade 2 has the configuration and shape as described above.
6a, the arrow B5 generated when the second blade 26a is rotated in the arrow B1 direction.
The directional airflow allows the bearing 21 to be cooled via the bracket 27b. Also, the second blade 26a is connected to the boss 4 of the flexible shaft joint 39.
0, the configuration including the electric motor 15a can be simplified without any processing of the electric motor 15a. Also, the arrow B5 by the second blade 26
Dust and the like that tend to accumulate near the bearing 21 can be removed by the air flow in this direction.

Further, since the cover member 46 having the above-described configuration is provided, the degree to which the airflow in the direction of arrow B4 caused by the first blade 22 is disturbed can be further reduced.

In the embodiment described above, the frame 16 has a hermetically sealed configuration, and the electric motor 15 has the first blade 2.
It is a completely enclosed external fan shape with 2.

In addition, the first blade 22 and the second blades 26, 26
A is not limited to a flat plate shape as explained in the above embodiment, and may also be such that the rotation direction of the output shaft is opposite to the direction of arrow B1. Also,
The shaft joint of the electric motor 15a is not limited to the flexible shaft joint 39 as explained in the above embodiment.

Effects As described above, according to the present invention, the air sent by the first blade 22 and the second blade 26a causes the output shaft to move in the frame 16 of the electric motor 15.
The bearings 20 and 21 supporting the bearings 9 are efficiently and reliably cooled.

Furthermore, in the present invention, the first and second blades 22,
26a sends outside air toward the frame 16 side,
Therefore, the bearings 20 and 21 can be efficiently cooled by the outside air having a relatively low temperature.

Furthermore, the second blade 26a and the cover member 46 that covers it have a diameter smaller than that of the first blade 22, so that the cooling fin 26a is connected to the first blade 22.
The bearing 21 on the second blade 26a side can be cooled by the air of the second blade 26a without causing disturbance in the air that cools the bearing 9.

The cover member 46 is spaced apart from the frame 16 in the axial direction by a distance d as shown in FIG. , it becomes easier to cool the frame 16 reliably without causing any turbulence in the air that cools the cooling fins 29 by the first blades 22.

According to the present invention, in an existing fully enclosed external sector electric motor in which cooling fins 29 are provided at one end of the output shaft 19, the other end of the output shaft 19 has an outer diameter smaller than that of the first blade 22. Second blade 26a
is fixed to enable cooling of the bearing on the other end side of the output shaft 19, and the air from the second blade 26a is guided to the bearing on the other end side of the output shaft 19 by the cover member 46. However, in this way, it is possible to reliably cool the bearings of the existing totally enclosed external sector electric motor.

Furthermore, according to the present invention, since the second blade 26a has a smaller outer diameter than the first blade 22,
The bearing can be cooled without the need to provide a shielding partition wall or an interference prevention plate for opposing cooling air flows from the first and second vanes 22, 26a, thereby simplifying the configuration. This effect is achieved.

Further, according to the present invention, the cover member 46 has a second
In addition to covering the blade 26a, it is also possible to partially cover the shaft coupling connected to the other end of the output shaft 19, thereby achieving the excellent effect of ensuring safety. be done.

[Brief explanation of the drawing]

FIG. 1 is a front view showing a partial cross section of an electric motor 15 showing the basic configuration of the present invention, FIG. 2 is a left side view of FIG. 1, and FIG. 4 is a perspective view of the second blade 26, FIG. 5 is a sectional view of the electric motor 15a according to an embodiment of the present invention, FIG. 6 is a perspective view of the cover member 46, and FIG. 7 is a perspective view of the second blade 26. FIG. 8 is a simplified cross-sectional view of another prior art electric motor 1. 15, 15a... electric motor, 16... frame,
19... Output shaft, 20, 21... Bearing, 22...
First blade, 23... Cover, 26, 26a... Second blade, 39... Flexible shaft joint, 40...
Boss, 46...Cover member.

Claims (1)

[Claims for Utility Model Registration] In the cooling fins 29 formed on the frame 16,
In a bearing cooling device for a fully enclosed external fan type electric motor, in which intake air is guided by a first blade 22 fixed to one end of the output shaft 19 through a cover 23, a frame 16 fixed to the other end of the output shaft 19
a second blade 26a that sends air to the side and has a smaller outer diameter than the first blade 22; and a second blade 26a coaxially with the frame 16;
It has a smaller diameter than the frame 16, has an intake port on the opposite side to the frame 16, is provided axially away from the frame 16, and directs air by the second blade 26a radially inward as it approaches the frame 16. A bearing cooling device for an electric motor, comprising a cover member 46 having a truncated cone shape.