JP2010063280A - Internal pressure explosion-proof rotating electric machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress the leakage of a protection gas fed into a space in a body frame to the outside of an internal pressure explosion-proof rotating electric machine from a clearance between a penetration hole of an oil cut member and a rotating shaft via a space in a bearing housing. <P>SOLUTION: The internal pressure explosion-proof rotating electric machine 1 comprises: a body frame 4 which accommodates a stator, is fed with the protection gas, and is kept higher in pressure than atmospheric pressure; the rotating shaft 3 which rotates together with a rotor which can rotate in the stator; a sliding bearing 2 which supports the rotating shaft 3 at the outside of the body frame 4, and is fed with a lubricating oil; the bearing housing 5 which is arranged adjacent to the body frame 4 to accommodate the sliding bearing 2; the oil cut member 6 which has a hole penetrated with the rotating shaft 3, and partitions the space 4a in the body frame and the space 5a in the bearing housing; and a seal member 7 which is attached to the oil cut member 6, and has a plurality of annular protrusions which are formed along the surrounding of the rotating shaft 3 at intervals in the axial direction of the rotating shaft 3, and protrude inwardly in the radial direction toward the rotating shaft 3. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an internal pressure explosion-proof rotating electrical machine including a slide bearing.

  The internal pressure explosion-proof rotating electrical machine is installed in an atmosphere containing flammable gas, and the protective gas is constantly supplied into the rotating electrical machine to maintain the atmospheric pressure in the rotating electrical machine at a pressure higher than the atmospheric pressure. This prevents the flammable gas from entering the gas.

  An internal pressure explosion-proof rotating electrical machine having a conventional slide bearing will be described with reference to FIG. FIG. 5 is a cross-sectional view of the vicinity of a sliding bearing in a conventional internal pressure explosion-proof rotating electrical machine.

  The conventional internal pressure explosion-proof rotating electrical machine 11 includes a main body frame 14 and a bearing housing 15. The internal pressure explosion-proof rotating electrical machine 11 has a stator and a rotor in a main body frame inner space 14a, a slide bearing 12 in a bearing housing inner space 15a, and a main body frame inner space 14a and a bearing housing inner space 15a. A rotating shaft 13 is provided. Further, the body frame inner space 14 a and the bearing housing inner space 15 a are partitioned by an oil draining member 16. Furthermore, the internal pressure explosion-proof rotating electrical machine 11 has a protective gas supply mechanism that supplies protective gas from the air supply port to the main body frame inner space 14a and discharges it from the exhaust port to the outside of the internal pressure explosion-proof rotating electrical machine 11.

  However, in the conventional internal pressure explosion-proof rotating electrical machine 11, the protective gas supplied to the main body frame inner space 14 a passes through the clearance between the through hole of the oil draining member 16 and the rotary shaft 13 through the inner space 15 a of the bearing housing. It leaks out of the explosion-proof rotating electrical machine 11. Therefore, in order to keep the atmospheric pressure in the main body frame inner space 14a at a desired atmospheric pressure, it is necessary to increase the flow rate of the protective gas to be supplied, and the necessity of increasing the size of the protective gas supply mechanism and the increase in cost have been problems. .

For suppressing leakage of protective gas or the like from the through hole or the bearing portion to the outside of the rotating electrical machine, the clearance between the through hole of the oil draining member 16 and the rotary shaft 13 is reduced by reducing the inner diameter of the through hole. In addition, various proposals (Patent Documents 1, 2 and 3) are known.
JP-A-9-149600 JP 2006-234106 A JP 2001-86703 A

  The present invention has been made in order to solve the above-described problems, and the purpose of the present invention is to prevent the protective gas supplied to the space inside the main body frame from passing through the clearance between the through hole of the oil draining member and the rotary shaft. Thus, an internal pressure explosion-proof rotating electrical machine that can suppress leakage outside the machine is provided.

  In order to achieve the above object, an internal pressure explosion-proof rotating electrical machine according to the present invention accommodates a stator, a main body frame that is supplied with a protective gas and maintained at a pressure higher than atmospheric pressure, and is rotatable within the stator. A rotating shaft that rotates together with the rotor, a sliding bearing that supports the rotating shaft outside the main body frame and that is supplied with lubricating oil, and a bearing that is provided adjacent to the main body frame and houses the sliding bearing A housing, an oil draining member having an opening through which the rotary shaft passes, and partitioning the space in the main body frame and the space in the bearing housing; and attached to the oil draining member and spaced apart from each other in the axial direction of the rotary shaft And a seal member provided with a plurality of annular protrusions arranged along the periphery of the rotation shaft and projecting radially inward toward the rotation shaft.

  According to the present invention, the protective gas supplied to the inner space of the main body frame is prevented from leaking from the clearance between the through hole of the oil draining member and the rotating shaft to the outside of the internal pressure explosion-proof rotating electrical machine via the inner space of the bearing housing. can do.

[First Embodiment]
Hereinafter, a first embodiment of an internal pressure explosion-proof rotating electrical machine according to the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is an upper half partial vertical sectional view in the vicinity of a slide bearing in an internal pressure explosion-proof rotating electrical machine according to the present embodiment. FIG. 2 is an enlarged vertical sectional view of the upper half of the vicinity of the seal member of FIG.

  The internal pressure explosion-proof rotating electrical machine 1 includes a main body frame 4 and a bearing housing 5 adjacent to the main body frame 4 in the axial direction. The internal pressure explosion-proof rotating electrical machine 1 has a stator and a rotor in a main body frame inner space 4a, and a sliding bearing 2 in a bearing housing inner space 5a. The internal pressure explosion-proof rotating electrical machine 1 has a rotating shaft 3 that passes through the body frame inner space 4a and the bearing housing inner space 5a and rotates together with the rotor. Further, the internal pressure explosion-proof rotating electrical machine 1 has an oil draining member 6 that partitions the main body frame inner space 4 a and the bearing housing inner space 5 a, and a seal member 7 is attached to the oil draining member 6.

  The rotating shaft 3 is a metal shaft having a cylindrical cross section. The rotating shaft 3 passes through the body frame inner space 4 a and the bearing housing inner space 5 a and is rotatably supported by the slide bearing 2. In addition, there is another bearing at the right end (not shown) of the main body frame 4 in FIG. 1, and the rotary shaft 3 is rotatably supported.

  The slide bearing 2 is disposed in the bearing housing inner space 5a and rotatably supports the rotary shaft 3. The sliding bearing 2 has a lubricating oil supply mechanism (not shown), and the lubricating oil supply mechanism supplies lubricating oil between the sliding bearing 2 and the rotary shaft 3.

  The main body frame 4 houses a stator, a rotor, various electric parts, and the like. Further, the atmospheric pressure in the main body frame space 4a is maintained at a pressure higher than the atmospheric pressure by constantly supplying a predetermined flow rate of the protective gas to the main body frame space 4a by a protective gas supply mechanism (not shown). As the protective gas, clean air or the like is used. Therefore, even if the internal pressure explosion-proof rotating electrical machine 1 is installed in an atmosphere having a flammable gas, the flammable gas can be prevented from entering the main body frame inner space 4a.

  The oil draining member 6 has a through hole 6a through which the rotary shaft 3 passes, and is disposed at a position that partitions the body frame inner space 4a and the bearing housing inner space 5a. Therefore, it is possible to prevent the lubricating oil supplied to the slide bearing 2 from scattering into the main body frame inner space 4a.

  The seal member 7 includes, for example, three annular seal plates 7a arranged in the axial direction, and two annular spacers 7b sandwiched therebetween. The annular seal plate 7 a is a perforated disc whose inner diameter is designed to be the same as or slightly larger than the diameter of the rotary shaft 3. The annular spacer 7b is a perforated disk whose inner diameter is slightly larger than the inner diameter of the annular seal plate 7a and whose outer shape is designed to be the same as the outer shape of the annular seal plate 7a. The annular seal plate 7a is made of, for example, a fluororesin such as Teflon (trade name). The seal member 7 is formed by concentrically laminating three annular seal plates 7a and two annular spacers 7b alternately in the axial direction. The seal member 7 is attached to a side surface of the oil draining member 6 on the side of the body frame inner space 4a via a contact plate 7e and is disposed along the periphery of the rotary shaft 3. Thereby, there is a gap 7 c between the seal member 7 and the rotary shaft 3.

  In the present embodiment, when the inner diameter of the annular seal plate 7a is designed to be the same as the diameter of the rotary shaft 3, the gap between the annular seal plate 7a of the seal member 7 and the rotary shaft 3 can be designed to a minimum. The protective gas supplied to the body frame inner space 4a is prevented from leaking out of the internal pressure explosion-proof rotating electrical machine 1 from the clearance between the through hole 6a of the oil draining member 6 and the rotary shaft 3 through the bearing housing inner space 5a. can do.

  On the other hand, in the present embodiment, when the inner diameter of the annular seal plate 7 a is designed to be larger than the diameter of the rotary shaft 3, a plurality of gaps 7 c are formed between the seal member 7 and the rotary shaft 3. When the protective gas supplied to the space 4a in the main body frame passes through the gap between the seal member 7 and the rotary shaft 3, the flow path of the protective gas repeats abrupt contraction and expansion, and the pressure loss increases. To do. As a result, the amount of protective gas leaking into the bearing housing inner space 5a can be suppressed. That is, it is possible to prevent the protective gas supplied to the main body frame inner space 4a from leaking out of the internal pressure explosion-proof rotating electrical machine 1.

  Furthermore, in the present embodiment, if the inner diameter of the annular seal plate 7a is designed to be the same as or larger than the diameter of the rotary shaft 3, if the fluororesin is used for the annular seal plate 7a, the rotary shaft 3 Therefore, even if it contacts the rotating shaft 3, the rotating shaft 3 is not damaged, and the wear resistance is high. Thereby, the clearance gap between the annular seal board 7a and the rotating shaft 3 can be designed to the minimum. As a result, the protective gas leakage suppression effect can be further increased.

[Second Embodiment]
A second embodiment of the internal pressure explosion-proof rotating electrical machine according to the present invention will be described with reference to FIG. FIG. 3 is an upper half partial vertical cross-sectional view enlarging the vicinity of the seal member in the internal pressure explosion-proof rotating electrical machine according to the present embodiment. In addition, this embodiment is a modification of 1st Embodiment, Comprising: The same code | symbol is attached | subjected to the same part or similar part as 1st Embodiment, and duplication description is abbreviate | omitted.

  In this embodiment, the seal member 7 includes an annular seal plate 7a attached to the side surface of the oil draining member 6 on the main body frame inner space 4a side, one annular spacer 7b, and the rotary shaft 3 side of the oil draining member 6 on the rotary shaft 3 side. The seal ring 7 d is attached to a groove formed on the side surface, and a gap 7 c is provided between the seal member 7 and the rotary shaft 3. Also in this embodiment, the same effect as that of the first embodiment can be obtained.

[Third Embodiment]
A third embodiment of the internal pressure explosion-proof rotating electrical machine according to the present invention will be described with reference to FIG. FIG. 4 is an upper half partial vertical cross-sectional view enlarging the vicinity of the seal member in the internal pressure explosion-proof rotating electrical machine according to the present embodiment. In addition, this embodiment is a modification of 1st Embodiment, Comprising: The same code | symbol is attached | subjected to the same part or similar part as 1st Embodiment, and duplication description is abbreviate | omitted.

  In the present embodiment, the seal member 7 has a cylindrical shape, and has three annular protrusions protruding radially inward toward the rotation shaft 3 at intervals in the rotation axis direction on the inner wall thereof. ing. The seal member 7 is made of a fluororesin such as Teflon (trade name) and is integrally formed by injection molding. Also in this embodiment, the same effect as that of the first embodiment can be obtained.

[Other Embodiments]
The above embodiments are merely examples, and the present invention is not limited thereto. For example, in the first embodiment, the seal member 7 in which the number of the annular seal plates 7a and the annular spacers 7b is further increased may be used. Moreover, you may combine the characteristic of each embodiment. For example, the seal ring 7d in FIG. 3 may be attached to a groove formed on the side surface on the rotating shaft 3 side of the oil draining member 6 in FIG. Also in these embodiments, the same effect as that of the first embodiment can be obtained.

1 is an upper half partial vertical sectional view of a vicinity of a slide bearing in an internal pressure explosion-proof rotating electrical machine according to a first embodiment of the present invention. It is the upper half partial longitudinal cross-sectional view which expanded the seal member vicinity of FIG. It is the upper half partial longitudinal cross-sectional view which expanded the seal member vicinity in the internal pressure explosion-proof rotary electric machine which concerns on the 2nd Embodiment of this invention. It is the upper half partial longitudinal cross-sectional view which expanded the seal member vicinity in the internal pressure explosion-proof rotary electric machine which concerns on the 3rd Embodiment of this invention. It is an upper half partial longitudinal cross-sectional view near a slide bearing in a conventional internal pressure explosion-proof rotating electrical machine.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Internal pressure explosion-proof rotary electric machine, 2 ... Slide bearing, 3 ... Rotating shaft, 4 ... Body frame, 4a ... Body frame inner space, 5 ... Bearing housing, 5a ... Bearing housing inner space, 6 ... Oil draining member, 6a ... Through hole, 7 ... seal member, 7a ... annular seal plate, 7b ... annular spacer, 7c ... gap, 7d ... seal ring, 7e ... contact plate

Claims (4)

A body frame that houses the stator and is supplied with protective gas and maintained at a pressure higher than atmospheric pressure;
A rotating shaft that rotates with a rotor rotatable within the stator;
A sliding bearing that supports the rotating shaft outside the main body frame and is supplied with lubricating oil;
A bearing housing that is provided adjacent to the main body frame and houses the slide bearing;
An oil draining member that has an opening through which the rotating shaft passes and partitions the space in the main body frame and the space in the bearing housing;
A plurality of annular protrusions attached to the oil draining member and arranged along the periphery of the rotary shaft at intervals in the axial direction of the rotary shaft and projecting radially inward toward the rotary shaft A seal member comprising:
An internal pressure explosion-proof rotating electrical machine characterized by comprising:   The seal member includes a plurality of annular seal plates having a spreading surface extending in a direction perpendicular to the rotation axis and constituting the protruding portion, and an inner periphery of the annular seal plate disposed between the annular seal plates. 2. The internal pressure explosion-proof rotating electrical machine according to claim 1, further comprising at least one annular spacer retracted toward the outer peripheral side.   The internal pressure explosion-proof rotating electrical machine according to claim 1 or 2, wherein the protruding portion is configured to slide with the rotating shaft.   The internal pressure explosion-proof rotating electrical machine according to claim 3, wherein the protruding portion is made of a fluororesin.

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