JP2015142437A - motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent flood from the outside or moisture stagnation to the vicinity of a gap between a shaft and an end bracket, in a simple configuration independent of an installation place of a motor.SOLUTION: The motor comprises at least: a housing 10; an end bracket 7; a cooling fan 4 which is rotated together while being connected to the vicinity of an end portion of a rotor shaft penetrating the end bracket; and a fan cover 11 including a hole 11a communicating with the outside on a surface parallel to the end bracket, and covering the end bracket and the cooling fan. The cooling fan has a substantially circular shape in which a base part 4b is inclined in a direction of the end bracket from a center to an outer periphery, and includes blades substantially perpendicularly extending from the inclined plane in a direction opposite to the end bracket. An outer surface of the end bracket has an inclination (m-n) which becomes lower in an outer peripheral direction of the end bracket from an intersection with an axial extension of an outer periphery of the cooling fan.

Description

  The present invention relates to an electric motor, and more particularly to an electric motor having a waterproof structure.

  The electric motor may be installed outdoors, and its waterproofing has been achieved by various methods. In Patent Document 1, for the purpose of waterproofing between an end bracket of an electric motor and a rotor shaft (shaft) penetrating the end bracket, an annular structure that rotates together with the shaft is opposed to the outer surface of the end bracket. The invention to attach is disclosed. Two circular convex portions having different sizes around the axial center are provided on the surface facing the end bracket of the structure in the radial direction, and the outer surface on the end bracket side includes a circular shape including each circular convex portion. Are provided, and a labyrinth structure is formed by fitting them together. The labyrinth structure prevents water from entering the gap between the shaft and the end bracket.

  Moreover, the electric motor may include an external fan for cooling on the opposite side (back surface) to the output shaft. The outer fan fan rotates in the space formed by the fan cover and the end bracket according to the rotation of the shaft. The cooling air is sucked from an air inlet provided in the center of the fan cover, deflected by the fan cover, and led out to the outer periphery of the motor housing.

  When the electric motor is disposed sideways (the shaft is in a horizontal direction), since a fan cover is provided, it is possible to prevent water from entering the vicinity of the connecting portion between the shaft and the end bracket from above. Even if the water is submerged, it flows downward through the end bracket, and moisture does not stay near the connecting portion.

JP 2011-15479 A

  However, when the electric motor is placed vertically with the output shaft facing downward, moisture entering from the air inlet of the fan cover stays in the end bracket, and there is a possibility that the gap with the shaft is immersed in water. In order to prevent moisture from entering from above, it may be possible to install a dedicated cover above the intake port or to install the intake port in the circumferential direction of the fan cover. In the latter case, it is necessary to change the structure of the outer fan itself (no cooling airflow is generated). That is, it is necessary to change the specifications between the vertical placement and the horizontal placement.

  As in Patent Document 1, it is also effective to directly arrange some kind of sealing member against water entering the gap between the shaft and the end bracket, but in the first place, moisture from the outside does not enter the vicinity of such a gap. It is also important to avoid or stay. A waterproof technology that does not depend on the installation direction of the electric motor with a single configuration that is not complicated is desired.

  In order to solve the above-described problems, for example, the configuration is set forth in the claims. That is, a housing, an end bracket, a cooling fan that is connected in the vicinity of the end of the rotor shaft that passes through the end bracket and rotates together, and a fan that has an inlet on a surface parallel to the end bracket and covers the end bracket and the cooling fan An electric motor including at least a cover, wherein the cooling fan has a substantially circular shape with a base portion inclined toward the end bracket from the center toward the outer periphery, and is substantially vertical from the inclined surface toward the direction opposite to the end bracket. The outer surface of the end bracket has an inclination that decreases toward the outer periphery of the end bracket from the intersection with the axial extension line of the outer periphery of the cooling fan.

  According to one aspect of the present invention, there is an effect that waterproofing can be performed without depending on the installation direction of the electric motor. Other problems and effects will become clear from the following description.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view illustrating an axial waist section of a squirrel-cage induction motor that is an embodiment to which the present invention is applied. It is the schematic diagram which expanded the waist | hip | lumbar part of this embodiment. It is a schematic diagram which shows the example of the flow of the water | moisture content in this embodiment.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. In this embodiment, a squirrel-cage induction motor will be described as an example.
FIG. 1 schematically shows a partial cross section in the end bracket side / axial direction of a squirrel-cage induction motor. A squirrel-cage induction motor is roughly divided into a rotating part and a fixed part.
First, the rotating part will be described. The rotating part includes a shaft 1 serving as an output shaft, a rotor 2 composed of laminated steel plates, a bearing 3 for supporting the shaft 1 with an end bracket 7, a fan 4 for rotating together with the shaft 1 and cooling the electric motor, A V-ring 5 (see an enlarged view of FIG. 2) for preventing water from entering between the shaft 1 and the fan 4 and a waterproof collar 6 for preventing water from entering the motor machine along the outer periphery of the shaft 1 are included.

  The waterproof collar 6 has a cylindrical shape having an inner diameter substantially the same as the diameter of the shaft 1. More specifically, the waterproof collar 6 has an outer diameter near one end (fan side) of the cylindrical shape that is larger than the outer diameter of the other end (output shaft side), and the other end of the end The part side surface has a circular groove whose cross section is a substantially U-shaped cross section. This circular groove fits into a circular convex portion provided on the end shaft described later.

  The waterproof collar 6 is fixed to the shaft 1 with the other (output shaft side) end contacting the side surface of the inner ring of the bearing 3 and a circular groove fitted to an end shaft circular convex portion described later. It is designed to rotate together.

  A recess for fitting the outer ring of the bearing 3 is formed on the rear surface side (output shaft direction surface) of the end bracket 7, and the shaft 1 extends to the vicinity of the outer periphery of the inner ring of the outer bearing 3 at the center of the bottom surface of the recess. A through-hole is provided in the radial direction. On the edge of the hole, a convex portion is provided toward the fan 4 side to form a circular convex portion. By fitting the circular convex portion and the circular groove of the waterproof collar 6 described above, it is possible to prevent water from entering from the outside.

Further, a gap 8 is provided between the bearing 3 and the concave bottom surface of the end bracket 7 and is filled with rust preventive oil. The rust preventive oil 8 also serves to prevent water from entering the bearing 3.
The fan 4 has a fan base 4a (see FIG. 2) and a plurality of blades. The fan 4 is fitted through the end of the shaft 1 protruding from the end bracket 7, and is fixed with a screw or the like. . The V ring 5 is fixed in a state where it is in contact with the fan 4 in order to seal water intruding into the joint surface between the shaft end of the shaft 1 and the fan 4.

  Next, the fixing part will be described. The fixed portion includes a stator core 9, a coil 14 wound around the stator core 9, a housing 10 that forms an outer wall in the circumferential direction of the electric motor, an end bracket 5 that forms an outer wall in the axial direction of the electric motor, and the end bracket 5 and the fan 4. An end cover 11 is included.

  The fan cover 11 has its outer peripheral end and the outer peripheral end of the end bracket 7 fixed with bolts so as to cover the end bracket 7 and the fan 4. As a result, a closed space is formed by the end cover 11 and the end bracket 7. A plurality of intake ports 11 a communicating with the outside are provided on the side surface in the axial direction of the end cover 11. Note that a confirmation hole 11b for manually confirming the motor is also provided at the center of the side surface in the direction. The confirmation hole 11b is usually covered with a cap such as rubber.

An in-slot insulator 13 is inserted into the stator core slot 12. This in-slot insulator 13 is provided to electrically insulate between the stator core 9 and the coil 14 and between the coils 14.
A lead wire 15 is connected near the terminal end of the coil 14 protruding from the stator core 9. The lead wire 15 is accommodated in the terminal box 16 with the inner wall of the housing 10 turned upside down.

Here, the waterproof structure which is one of the features of the present embodiment will be described.
As shown in FIG. 1, a corner portion in the end portion circumferential direction of the shaft 1 and a corner portion in the end portion circumferential direction of the waterproof collar 6 are molded in a shape inclined toward the electric motor main body. The main body of the fan 4 is also formed in a curved shape so that the outer periphery is inclined toward the end bracket. Further, the outer surface of the end bracket 7 is also formed to be inclined toward the output shaft direction from the axially extended position of the outer diameter n of the fan 4 to the position of the outer side m. An outer peripheral end corner portion of the end cover 11 is also formed in a shape inclined to the electric motor side.

  With these configurations, when the squirrel-cage induction motor is vertically arranged, moisture that enters from the upper side through the intake port 11a is guided to the outer peripheral side of the housing 10 to prevent moisture from staying on the outer surface of the end bracket 7. Intrusion into the gap between the shaft 1 and the end bracket 7 is prevented.

  FIG. 3 schematically shows a flow of discharging moisture from above. For example, moisture that enters the side surface of the end of the shaft 1 from the air inlet 11 a flows through the V ring 5 along the inclination of the corner of the shaft 1. After that, it moves to the fan 4 through the inclination of the V ring 5 and falls to the end bracket 7 along the inclination. Since the surface of the end bracket 7 at the drop destination is inclined, the moisture further flows in the outer peripheral direction, and eventually drains to the outer peripheral surface of the housing 10 beyond the outer periphery. In addition, the water | moisture content which penetrate | invaded directly into the V ring 5 or the fan 4 from the upper direction is drained similarly by each inclination.

  In this way, each part and the inclination formed in each part create a flow that directs moisture from above toward the outer periphery of the housing 10, so that moisture may stay on the outer surface of the end bracket 7. Furthermore, since the vicinity of the center of the outer surface of the end bracket 7 is one step higher than the outer circumferential surface, it is possible to prevent moisture from entering the vicinity of the joint between the shaft 1 and the end bracket 7. An effect can be obtained.

  Conventionally, the V-ring 5 is fixed to the shaft 1 and brought into contact with the end bracket 7 to achieve waterproofing. However, wear caused by contact with the end bracket 7 due to rotation required periodic replacement. In this embodiment, since it is configured to be fixed to the shaft 1 so as to come into contact with the fan 4, there is no problem of wear, and it may be resin, rubber or the like.

  Further, since the end bracket 7 is inclined at a position between n and m, moisture retention on the outer surface of the end bracket 7 can be prevented if the outer diameter of the fan 4 satisfies n. Therefore, it is possible to reduce the size of the fan 4 within a range that satisfies this relationship according to the specifications of the electric motor.

  Further, since the outer surface near the center of the end bracket 7 is the highest and the outer surface near the outer periphery of the housing 10 is the lowest, it is blown by wind or the like, and the gap between the end bracket 5 and the end cover 11 (cooling air) It is also possible to discharge moisture that enters from the discharge port.

  As mentioned above, although the form for implementing this invention was demonstrated, this invention can apply a various structure in the range which does not deviate from the meaning. For example, the outer surface of the end bracket 7 may be continuously inclined without being inclined stepwise. Further, for example, the fan 4 is not limited to a curved shape, and the cross section may be a straight slope or a bottom slope. Further, for example, the V ring 5 may be provided at the joint between the waterproof collar 6 and the shaft 1 or may be added. In addition, the effects of the present invention can be sufficiently obtained with only some of the components without applying all the configurations of the present embodiment.

DESCRIPTION OF SYMBOLS 1 ... Shaft, 2 ... Rotor, 3 ... Bearing, 4 ... Fan, 4a ... Fan base, 5 ... V ring, 6 ... Waterproof collar, 7 ... End bracket, 8 ... Gap, 9 ... Stator core, 10 ... Housing, 11 ... Fan cover, 12 ... stator core slot, 13 ... insulator, 14 ... coil, 15 ... lead wire, 16 ... terminal box

Claims (4)

A fan cover that covers the end bracket with a housing, an end bracket, a cooling fan that is connected to the end of the rotor shaft that passes through the end bracket and rotates together, and a hole that communicates with the outside in a plane parallel to the end bracket An electric motor comprising at least
The cooling fan has a substantially circular shape whose base portion is inclined in the direction of the end bracket from the center toward the outer periphery, and has blades extending substantially vertically from the inclined surface toward the direction opposite to the end bracket,
The electric motor in which the outer surface of the end bracket has a slope that becomes lower toward the outer periphery of the end bracket from the intersection with the axial extension line of the outer periphery of the cooling fan. The electric motor according to claim 1,
An electric motor in which the cooling fan is connected through the rotor shaft end portion, and a corner portion of the rotor shaft end portion has a slope inclined in the outer peripheral direction. The electric motor according to claim 1 or 2,
An electric motor in which the cooling fan is connected through the rotor shaft end, and has a seal ring whose one side surface is in contact with the cooling fan on an outer periphery protruding from the cooling fan at the rotor shaft end. 4. The electric motor according to claim 1, further comprising a collar member on the rotor shaft between the end bracket and the cooling fan,
The collar member has an annular groove centered on the rotor shaft on the surface facing the end bracket,
The end bracket has an annular projection that fits into the annular groove,
The collar member is an electric motor provided on a rotor shaft such that the annular groove and the annular convex portion are rotatably fitted.

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