JP2010288350A - Waterproof structure of motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a waterproof structure for a motor in a bad environment in which high pressure water intrudes. <P>SOLUTION: The waterproof structure 1 of the motor 2 is configured by providing a second member 3 and a third member 4 in the direction of extension of the output shaft 2a of the motor 2 in this order. The second member surrounds a bearing of the output shaft 2a and allows the penetration of the output shaft 2a. The third member surrounds the motor 2 and the second member 3 and allows the penetration of the output shaft 2a. The waterproof structure is provided with an annular first member 5 disposed and fixed on the outer surface of the output shaft 2a so that it is positioned between the second member 3 and the third member 4. The outside diameter of the first member is larger than the diameter of the opening in the second member 3 and the diameter of the opening in the third member 4. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a waterproof structure for an electric motor, and more particularly to a waterproof structure for an electric motor used in a poor environment where high-pressure water enters.

  As is well known, a plurality of steel plate cooling spray devices are installed in the traveling direction of the steel plate between the finish rolling mill and the winder arranged in the hot rolling line of the steel plate. The steel plate cooling spray device is a device that is installed above and below the steel plate to be conveyed and cools the steel plate by spraying water from above and below. The steel plate cooling spray device is controlled based on a measurement result of a thermometer (usually a radiation thermometer) installed at a predetermined position on a steel plate conveyance line.

  When measuring the temperature of the steel sheet with this radiation thermometer, if there is a large amount of water or water vapor on or near the surface of the steel sheet, accurate measurement cannot be performed, and accordingly the steel sheet cooling spray device is properly controlled. The steel sheet cannot be cooled to a desired temperature. In particular, water staying on the surface of the steel plate after being sprayed from the steel plate cooling spray device causes measurement errors of the radiation thermometer. The water staying on the surface of the steel sheet is removed by spraying high pressure water spray. A large amount of the high-pressure water spray sprayed in the width direction of the steel sheet flows out of the steel sheet conveying line.

  An electric motor for driving a steel sheet transport roll is installed beside the steel sheet transport line. The electric motor surrounds a bearing that rotatably supports the output shaft, and has a first casing that forms an annular first opening through which the output shaft passes with a gap, and the electric motor and the first electric motor. A second casing that surrounds one casing and forms an annular opening through which the output shaft of the motor passes with a gap is provided in this order in the extending direction of the output shaft. It has a waterproof and dustproof structure.

However, the water that has flowed out to the outside of the steel sheet conveyance line described above enters the bearing of the electric motor and the inside thereof, resulting in inevitable rotation of the bearing and defective insulation of the electric motor.
Patent Document 1 discloses an invention relating to a waterproof device in which a rolling cover is incorporated and a waterproof cover is attached to a bracket having a waterproof wall, and a slinger is provided on a rotating shaft so as to be positioned between the waterproof cover and the waterproof wall. Is disclosed. Further, in Patent Document 2, a first seal having an outward lip is attached to the side surface of the bearing portion of the rotary shaft, and a second seal having an outward lip is attached to the outer side thereof, Furthermore, the invention which concerns on the bearing sealing device provided with the gas piping which blows in the gas dehumidified in the space between the 1st and 2nd seals is disclosed.

  However, even with the inventions disclosed in Patent Documents 1 and 2, it is extremely difficult to prevent water flowing out to the outside of the steel sheet conveying line from entering the motor bearing and the interior thereof.

  Therefore, conventionally, an intermediate shaft is interposed between the steel sheet transport roll and the electric motor, and the motor is installed away from the steel sheet transport line, thereby preventing water from entering the motor bearing and the interior thereof. Yes.

Japanese Utility Model Publication No. 57-96817 Japanese Patent Laid-Open No. 8-4776

  However, this measure requires a large installation space and increases costs, so that it is actually difficult to adopt. In particular, the steel line conveyor line of the hot rolling line is generally long in order to ensure sufficient cooling time, and accordingly, the number of steel sheet transport rolls installed is large, so this countermeasure is implemented. Requires a large amount of capital investment and is difficult to actually adopt.

  As described above, the conventional technology cannot easily waterproof the motor and its bearing used in a poor environment where high-pressure water intrudes without requiring a large capital investment and a large installation space. .

  The present invention relates to a waterproof structure for an electric motor used in such an inferior environment. Briefly, if a baffle plate is directly attached to the output shaft of the motor, the baffle plate rotates with the output shaft. This is based on the technical idea that water that tries to enter the motor bearing and motor from the direction of the extension of the output shaft can be cut off easily and completely without requiring large capital investment and large installation space. .

  In the broadest sense, the present invention is characterized by comprising an annular first member that is fixedly disposed on the outer surface of the output shaft of the electric motor and prevents the flow of water along the axial direction of the output shaft. This is a waterproof structure for an electric motor.

  Specifically, the waterproof structure of the electric motor according to the present invention further includes an annular first opening that surrounds a bearing that rotatably supports the output shaft of the electric motor and that the output shaft penetrates with a gap. A second member that forms a portion, and a third member that surrounds the electric motor and the second member and forms an annular second opening through which the output shaft penetrates with a gap. The first member is arranged in this order in the extending direction, and the first member is disposed between the second member and the third member, and the outer diameter thereof is the diameter of the first opening, And larger than both of the diameters of the second openings.

  In the waterproof structure of the electric motor according to the present invention, the first member is (i) fixed to the outer surface of the output shaft in a watertight state, (ii) configured integrally in the circumferential direction, (iii) It is desirable to be made of an anticorrosive material, and (iv) to be fixed to the outer surface of the output shaft by providing a fixed key that is pushed into a key groove formed on the inner surface thereof.

  In the waterproof structure of the electric motor according to the present invention, it is desirable to further include an annular fourth member that is fixed and arranged on the outer surface of the output shaft so as to be positioned between the electric motor and the second member. . Thereby, waterproofness can further be improved.

  In this case, the fourth member is fixed in relation to the small diameter portion provided in a step shape on the output shaft and has a predetermined thickness, and the first member is in contact with the fourth member. It is desirable to be arranged. As a result, the first member can be accurately and reliably fixed at a predetermined position of the output shaft.

  In the waterproof structure of the electric motor according to the present invention, it is exemplified that the electric motor is an electric motor that is arranged on the side of the conveying line of the hot-rolled steel sheet and drives the steel sheet conveying roller.

  According to the present invention, the first member mounted on the output shaft rotates together with the output shaft, and blows away water that is about to enter the motor bearing and the motor from the extending direction of the output shaft in the circumferential direction thereof. Therefore, it can be cut off easily and completely without requiring large capital investment and a large installation space.

  In particular, according to the present invention, the first member attached to the output shaft closes the gap between the output shaft of the electric motor and the openings of the second member and the third member. The water that rotates with this gap and blows water in the circumferential direction from the extending direction of the output shaft through the clearance of the output shaft in the circumferential direction, so there is no need for a large capital investment and a large installation space Moreover, it can be cut off almost completely.

  Furthermore, according to the present invention, by providing the fourth member in particular, the waterproofness can be further improved, the first member can be easily attached and adjusted after the installation, and maintenance after the installation is also possible. It is unnecessary.

  In this way, according to the present invention, water intrusion into the motor and the bearing is prevented, so that failure due to water intrusion (such as bearing rotation failure and motor insulation failure) is prevented, and the motor is lengthened. It can be used continuously over a period of time.

Fig.1 (a) is explanatory drawing which shows the waterproof structure of the electric motor of embodiment, FIG.1 (b) is an enlarged view of the A section vicinity of Fig.1 (a). FIG. 2 is an enlarged view of the vicinity of part B in FIG.

  EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing the waterproof structure of the electric motor which concerns on this invention is demonstrated in detail, referring an accompanying drawing. In the following description, when the electric motor is an electric motor that is arranged on the side of the hot-rolled steel plate conveyance line and drives the steel plate conveyance roller, that is, the present invention is applied to the finish rolling mill of the hot rolling line. The case where it applies to the drive motor of the roll for steel plate conveyance installed in the side is taken as an example.

  Fig.1 (a) is explanatory drawing which shows the waterproof structure 1 of the electric motor 2 of this Embodiment, FIG.1 (b) is an enlarged view of the A part vicinity of Fig.1 (a). FIG. 2 is an enlarged view of the vicinity of the portion B in FIG.

Since the waterproof structure 1 of the present embodiment includes the first member 5, the second member 3, the third member 4, and the fourth member 7, these components will be described in order.
[Second member 3]
As shown in FIG. 1, the output shaft 2 a of the electric motor 2 is rotatably supported by a bearing 9. The output shaft 2 a is connected to a steel sheet transport roll (not shown) via a coupling (not shown), and is configured such that the steel sheet transport roll is driven by the electric motor 1. Reference numeral 8 in FIG. 1 is a base on which the electric motor 1 is placed.

A representative example of the second member 3 is a bearing cover. In the following description, a case where the second member 3 is a bearing cover is taken as an example.
The bearing cover 3 has a shape surrounding the bearing 9 of the electric motor 1. The bearing cover 3 is provided with an annular opening through which the output shaft 2a penetrates with a gap. The bearing cover 3 is fixed around the bearing 9 by appropriate means such as screwing.

The bearing cover 3 may be a well-known and conventional one of this type, and such a member is also used in the present embodiment, so that further description of the bearing cover 3 is omitted.
[Third member 4]
A representative example of the third member 4 is an electric motor cover. In the following description, the case where the third member 4 is an electric motor cover is taken as an example.

  The electric motor cover 4 surrounds the electric motor 2 and the bearing cover 3. Further, similarly to the bearing cover 3, the motor cover 4 is provided with an annular opening through which the output shaft 2 penetrates with a gap. The electric motor cover 5 does not necessarily need to enclose all of the electric motor 2 and the bearing cover 3 with a slight gap, and covers the portion where water may enter depending on the target water intrusion route. That's fine. For example, since water does not enter from the side opposite to the water intrusion route (left side in FIG. 1 (a)), it may be opened as shown in FIG. 1 (a).

The motor cover 4 may be a well-known and commonly used one of this kind, and such a cover is also used in the present embodiment, so that further description of the motor cover 4 is omitted.
[First member 5]
The first member 5 is a feature of the present invention. In the present embodiment, focusing on its functional aspect, the first member 5 will be referred to as a waterproof ring in the following description.

  The waterproof ring 5 is fixed to the outer surface of the output shaft 2a of the electric motor 2 as shown in FIG. The waterproof ring 5 is disposed so as to be positioned between the bearing cover 3 and the motor cover 4 with respect to the axial direction of the output shaft 2a.

  The outer diameter of the waterproof ring 5 is formed in the bearing cover 3 in order to prevent water from entering from the extending direction of the output shaft 2a (the left and right directions in FIGS. 1 (a), 1 (b), and 2). It is desirable that it is larger than both the diameter of the opening and the diameter of the opening formed in the motor cover 4.

  In the present embodiment shown in FIGS. 1A, 1B, and 2, the annular waterproof ring 5 is fixed to the sleeve 6 fixed to the output shaft 2a. However, the waterproof ring 5 may be directly fixed to the output shaft 2 a without the sleeve 6.

  The shape of the waterproof ring 5 is preferably an annular shape because it is easy to manufacture, but it is not necessary to be an annular shape. If the annular shape is an object with respect to the rotation axis, such as a regular hexagon or a regular octagon, Good.

  It is desirable that the waterproof ring 5 is fixed to the output shaft 2a in a watertight state in order to prevent water from entering from a contact portion with the output shaft 2a. In order to fix the waterproof ring 6 to the output shaft 2a in a watertight state, the contact portion between the output shaft 2a and the waterproof ring 5 is sealed, or the outer diameter of the output shaft 2a and the inner diameter of the waterproof ring 5 are set as much as possible. It should be close.

  Further, the distance between the waterproof ring 5 and the bearing cover 3 in the extending direction of the output shaft 2a (distance L0 in FIG. 2) is driven by the mechanical movement allowance in the axial direction of the output shaft 2a of the electric motor 2 and the electric motor 2. It is desirable to make it larger than the sum of the mechanical movement allowances in the axial direction of the steel sheet transporting rolls to be driven.

Since the waterproof ring 5 is used in a poor environment where high-pressure water enters, it is desirable that the waterproof ring 5 be made of an anticorrosive material such as stainless steel or plated steel.
In order to improve the workability of the replacement work, the waterproof ring 5 has an effect even if the output shaft 2a is sandwiched between bolts and the like, for example. In the case of application, there is a possibility that a trouble may occur in which it moves in the axial direction of the output shaft 2a due to the pressure of the high-pressure water and comes into contact with the bearing cover 3 disposed in the vicinity. For this reason, it is desirable to use the waterproof ring 5 integrally formed in the circumferential direction, for example, manufactured by cutting out from a material.

[Fourth member 7]
The 4th member 7 shown in FIG.1 (b) and FIG.2 assists the waterproof ring 5 which is the 1st member which makes the characteristic of this invention, and further improves waterproofness, In this Embodiment Focusing on the functional aspect, the fourth member 7 will be referred to as an internal waterproof ring in the following description.

The internal waterproof ring 7 is an annular member having a predetermined thickness, and is fixed to the outer surface of the output shaft 2 a of the electric motor 2 so as to be positioned between the electric motor 2 and the bearing cover 3.
As shown in FIG. 1B, the internal waterproof ring 7 is provided in a stepped manner at a predetermined position on the output shaft 2a of the electric motor 2 that is a predetermined distance away from the installation position of the waterproof ring 5 in the axial direction. The small diameter portion 2b is fixed in relation to the small diameter portion 2b. And the waterproof ring 5 presses the end surface of the sleeve 6 which fixes the waterproof ring 5 to the internal waterproof ring 7 fixed in the predetermined position in the output shaft 2a of the electric motor 2 in this way. 2 is fixed to the output shaft 2a.

  In this state, the waterproof ring 5 can be firmly fixed to a predetermined position of the output shaft 2 by press-fitting a fixed key into a key groove preliminarily formed on the inner surface of the sleeve 6. Fixing with a fixed key is suitable for adjustment in narrow spaces and precise adjustment. In order to change the installation position of the sleeve 6 in the axial direction, the thickness of the internal waterproof ring 7 may be changed, or the number of the internal waterproof rings 7 arranged in a stacked manner may be changed.

Thus, the waterproof ring 5 can be reliably arranged at a predetermined position of the output shaft 2a with the internal waterproof ring 7 as a reference.
As with the waterproof ring 5, the internal waterproof ring 7 is fixed to the outer surface of the output shaft 2a of the electric motor 2 in a watertight state, integrally formed in the circumferential direction, and further made of an anticorrosive material. desirable.

The waterproof structure 1 of the electric motor 2 of the present embodiment is configured as described above. Next, the waterproofing of the electric motor 2 by the waterproof structure 1 will be described.
When high-pressure water jets from the right to the left in FIG. 1A in the direction in which the output shaft 2 a extends, a considerable amount of water is repelled by the motor cover 4. However, water enters through an annular opening provided in the motor cover 4.

  In the conventional waterproof structure in which the waterproof ring 5 of the present embodiment is not attached, the invading water further enters the inside through an annular opening provided in the bearing cover 3, and finally the bearing 9 and the electric motor 2 It penetrates into the interior of the machine and causes serious effects (bearing rotation failure, motor insulation failure, etc.).

  However, in the present embodiment, since the waterproof ring 5 is disposed between the motor cover 4 and the bearing cover 3, the water that has entered the interior through the annular opening of the motor cover 4 is prevented from flowing into the output shaft 2a. The waterproof ring 5 is fastened together with the output shaft 2a and is fastened together with the output shaft 2a. The waterproof ring 5 rotates at a high speed, and the waterproof ring 5 rotates in the circumferential direction, that is, in the direction perpendicular to the extending direction of the output shaft 2a. Blowed away by centrifugal force. Thereby, there is almost no water which goes to the extending direction of the output shaft 2a.

  The water blown off by the centrifugal force in the direction perpendicular to the extending direction of the output shaft 2a collides with the inner surface of the motor cover 4 and bounces off, but the gap between the waterproof ring 5 and the bearing cover 3 is narrow, and this Since the centrifugal force in the circumferential direction of the waterproof ring 5 acts on the water, the water can be almost completely prevented from entering the gap between the waterproof ring 5 and the bearing cover 3.

  Further, if the waterproof ring 5 is cut into a product shape from the material and is firmly fixed to the output shaft 2a by the internal waterproof ring 7 and the fixed key as shown in FIG. 1 (b), high-pressure water is discharged from the axial direction of the output shaft 2a. Even if it is received, the waterproof ring 5 can be prevented from contacting the bearing cover 3 without being displaced.

  Further, in the present embodiment, even if water enters the inside of the bearing cover 3 through a gap between the waterproof ring 5 and the bearing cover 3, the intruded water is provided on the output shaft 2 a of the electric motor 2. The inner waterproof ring 7 that rotates at a high speed together with the output shaft 2a is damped, and the inner waterproof ring 7 that rotates at a high speed rotates the inner waterproof ring 7 in the circumferential direction, that is, the direction orthogonal to the extending direction of the output shaft 2a. It is blown away by force. Thereby, the water which goes to the extending direction of the output shaft 2a is completely lost.

  In this way, according to the present embodiment, the waterproof ring 5 attached to the output shaft 2a creates a gap between the output shaft 2a of the electric motor 2 and the openings of the bearing cover 3 and the electric motor cover 4 respectively. While closing, it rotates with the output shaft 2a, and the water that tries to enter the bearing of the electric motor 2 and the electric motor 2 from the extending direction of the output shaft 2a through this gap is blown away in the circumferential direction. It can be cut off almost completely without requiring a large installation space. Furthermore, by using the internal waterproof ring 7 together, the bearing of the electric motor 2 and the water that tries to enter the electric motor 2 can be completely eliminated.

  Therefore, according to the present embodiment, water intrusion into the electric motor 2 and the bearing 9 is completely prevented, so that failures due to water intrusion (such as defective rotation of the bearing 9 and defective insulation of the electric motor 2) are eliminated. The life of the electric motor 2 can be greatly extended.

DESCRIPTION OF SYMBOLS 1 Waterproof structure 2 Electric motor 2a Output shaft 2b Small diameter part 3 2nd member (bearing cover)
4 Third member (motor cover)
5 First member (waterproof ring)
6 Sleeve 7 Fourth member (internal waterproof ring)
8 Base 9 Bearing

Claims (9)

  A waterproof structure for an electric motor, comprising: an annular first member arranged to be fixed to an outer surface of an output shaft of the electric motor and blocking a flow of water along an axial direction of the output shaft.   A second member that surrounds a bearing that rotatably supports the output shaft of the electric motor and that forms an annular first opening through which the output shaft passes with a gap; the electric motor; A third member surrounding the two members and forming an annular second opening through which the output shaft penetrates with a gap, in this order in the extending direction of the output shaft, and The first member is disposed so as to be positioned between the second member and the third member, and the outer diameter thereof is the diameter of the first opening and the second opening. The waterproof structure for an electric motor according to claim 1, wherein the waterproof structure is larger than any of the diameters.   The waterproof structure for an electric motor according to claim 1, wherein the first member is fixed to an outer surface of the output shaft in a watertight state.   The waterproof structure for an electric motor according to any one of claims 1 to 3, wherein the first member is integrally formed in a circumferential direction.   The waterproof structure for an electric motor according to any one of claims 1 to 4, wherein the first member is made of an anticorrosive material.   6. The first member according to claim 1, wherein the first member is fixed to an outer surface of the output shaft by including a fixed key that is pushed into a key groove formed on an inner surface of the first member. Waterproof structure of the motor.   Furthermore, it is provided with the cyclic | annular 4th member fixed to the outer surface of the said output shaft so that it may be located between the said electric motor and the said 2nd member. The waterproof structure of the electric motor described in any one of the preceding items.   The fourth member is fixed in relation to a small diameter portion provided in a step shape on the output shaft and has a predetermined thickness, and the first member is disposed in contact with the fourth member. The waterproof structure for an electric motor according to claim 7.   9. The waterproof structure for an electric motor according to claim 1, wherein the electric motor is an electric motor that is disposed on a side of a conveying line of a hot-rolled steel plate and drives a roller for conveying the steel plate. 10. .

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