JP7249972B2 - Rotating electric machine, its bearing structure and shaft penetration seal structure - Google Patents

Description

The present invention relates to a rotary electric machine, its bearing structure, and shaft penetration seal structure.

2. Description of the Related Art A rotating machine is provided with a seal mechanism for preventing, for example, leakage of lubricating oil for sealing to the outside of the machine from a gap between a rotating portion and a stationary portion (see Patent Document 1). As a sealing mechanism, it is common to install a labyrinth or use an air seal.

JP-A-2005-102362

If the rotating electrical machine is a drip-proof type that is required to prevent outside air or moisture from entering the machine against the external water environment, the clearance at the labyrinth of the seal mechanism should be reduced to strengthen the sealing performance. Then, when the rotor shaft rotates, there is a problem that the temperature rises due to agitation loss of the air in the labyrinth.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to enhance the sealing performance without excessively reducing the clearance in the labyrinth of the sealing portion.

In order to achieve the above object, a bearing structure according to the present invention is a bearing structure for rotatably supporting a rotor shaft of a rotating electrical machine, comprising a bearing body directly supporting the rotor shaft, and a shaft shaft viewed from the bearing body. a shaft penetration portion seal structure provided on the opposite side of the rotor core in the direction of the shaft penetration portion and suppressing the intrusion of outside air and moisture into the bearing main body side, the shaft penetration portion seal structure including an inner labyrinth portion; an outer labyrinth portion; a seal structure space formed by the inner labyrinth portion and the outer labyrinth portion; It is characterized by having a formed partition plate, and an inner air supply section and an outer air supply section that supply sealing air to the inner space and the outer space, respectively.

Further, a rotary electric machine according to the present invention includes a rotor having a rotor shaft extending in the axial direction and a rotor iron core attached radially outwardly of the rotor shaft; and a stator winding axially penetrating through the stator core; and a stator that is supported stationary and is axially supported on both sides of the rotor core by the rotor shaft. a frame disposed radially outward of the stator; and two bearing brackets attached to both ends of the frame to support each of the two bearing structures. , wherein at least one of the two bearing structures includes a bearing body that directly supports the rotor shaft, and is provided on the opposite side of the rotor core in the axial direction as viewed from the bearing body, and a shaft-penetration portion seal structure for suppressing intrusion of outside air and moisture into the bearing main body side, wherein the shaft-penetration portion seal structure includes an inner labyrinth portion, an outer labyrinth portion, the inner labyrinth portion, and the outer labyrinth portion. a partition plate attached to the rotor shaft and formed to partition the seal structure space into an inner space and an outer space in the axial direction; the inner space and the outer space; and an inner air supply section and an outer air supply section for supplying seal air to the respective air supply sections.

According to the present invention, the sealing performance can be enhanced without excessively reducing the clearance in the labyrinth of the sealing portion.

BRIEF DESCRIPTION OF THE DRAWINGS It is a side view which shows the structure of the rotary electric machine which concerns on 1st Embodiment. FIG. 4 is a side view taken along the line II-II in FIG. 3 showing the configuration of the bearing structure of the rotary electric machine according to the first embodiment; 3 is a side view taken along line III-III in FIG. 2, showing the configuration of the bearing structure of the rotary electric machine according to the first embodiment; FIG. FIG. 3 is a partial cross-sectional view showing the details of the seal structure for the shaft-penetrating portion in the range indicated by part A in FIG. 2 of the bearing structure for the rotary electric machine according to the first embodiment; FIG. 3 is a partial cross-sectional view showing the details of the seal structure for the shaft-penetrating portion of the bearing structure for the rotary electric machine according to the first embodiment, which is shown in part B of FIG. 2 ; FIG. 10 is a partial cross-sectional view showing details of a shaft penetration portion seal structure of a bearing structure for a rotary electric machine according to a second embodiment; FIG. 11 is a partial cross-sectional view showing details of a shaft penetration portion seal structure of a bearing structure for a rotary electric machine according to a third embodiment;

A rotary electric machine, a bearing structure thereof, and a seal structure for a shaft penetration portion according to embodiments of the present invention will be described below with reference to the drawings. Here, parts that are the same or similar to each other are denoted by common reference numerals, and overlapping descriptions are omitted.

[First Embodiment]
FIG. 1 is a side view showing the configuration of a rotating electric machine 300 according to the first embodiment.

A rotating electric machine 300 has a rotor 10 , a stator 20 , a frame 30 , a bearing bracket 40 and a bearing structure 100 .

The rotor 10 has a rotor shaft 11 extending in the direction of the rotation axis (hereinafter referred to as axial direction), a rotor core 12 attached to the rotor shaft 11 , and an inner fan 15 attached to the rotor shaft 11 . The rotor core 12 is provided with a plurality of rotor bars 13 axially penetrating and circumferentially spaced from each other. The rotor 10 is rotatably supported by bearing structures 100 on both axial sides of the rotor shaft 11.
The stator 20 has a stator core 21 arranged radially outside the rotor core 12 and a stator winding 22 wound around the stator core 21 .

The frame 30 has a tubular shape extending in the axial direction, and is arranged radially outside the stator 20 so as to surround the stator 20 , the rotor core 12 and the inner fan 15 . The frame 30 is formed with one or more in-frame flow passages 31 extending in the axial direction for allowing the cooling gas to pass therethrough. The in-frame channel 31 communicates with the radially outer side of the inner fan 15 via a channel inlet 32 , and communicates with the space on the opposite side of the inner fan 15 with the rotor core 12 interposed therebetween through a channel outlet 33 . communicates through

A bearing bracket 40 is attached to each end of the frame 30 to provide stationary support for the bearing structure 100 respectively.

Hereinafter, in the axial direction, the side closer to the rotor core 12 or the direction toward the rotor core 12 is referred to as the inner side, and the side farther from the rotor core 12, that is, the side closer to the outside air or the direction toward the outside air side is referred to as the outer side. I will call.

2 is a side view taken along the line II-II in FIG. 3 showing the configuration of the bearing structure 100 of the rotary electric machine 300 according to the first embodiment, and FIG. 3 is a side view taken along the line III-III in FIG. It is a diagram.

The bearing structure 100 includes a bearing body 110 that directly receives the load of the rotor shaft 11, a bearing pad 120 attached to the radially outer side of the bearing body 110, and a bearing bracket 40 that surrounds the bearing pad 120. a bearing cap 130 axially supporting the bearing pads 120; an inner oil slinger 140 attached to the axially inner end of the bearing cap 130 and flared radially inward toward the rotor shaft; and an axial penetration seal arrangement 200 attached to the axially outer end of the .

The shaft penetrating portion seal structure 200 suppresses intrusion of outside air and moisture into the bearing main body 110 side. Details of the seal structure 200 for the shaft-penetrating portion will be described with reference to FIG. 4 for the A portion shown in FIG. 2 and FIG. 5 for the B portion shown in FIG. It has a partition plate 161 , an inner air supply portion 171 and an outer air supply portion 172 that supply air to a seal structure space 155 to be described later, and an inner discharge portion 173 and an outer discharge portion 174 that discharge air from the seal structure space 155 .

FIG. 4 is a partial cross-sectional view showing the details of the shaft penetration portion seal structure 200 in the range indicated by part A in FIG. 2 of the bearing structure 100 of the rotary electric machine 300 according to the first embodiment.

The shaft penetration portion seal structure 200 includes an outer oil slinger 150 on the stationary side, an inner air supply portion 171 for supplying sealing air, an outer air supplying portion 172 for supplying sealing air, and for discharging sealing air and moisture that has entered from the outside. inner discharge portion 173 (FIG. 5) and outer discharge portion 174 (FIG. 5), and a partition plate 161 on the rotating side.

The outer oil slinger 150 is connected to a support plate 151 whose outer peripheral side is supported by a bearing cap 130 supported by a bearing bracket 40 (FIG. 2) and has an opening formed in the center, and is connected to the opening of the support plate 151 to extend axially. an inner labyrinth portion 153 extending radially inward toward the rotor shaft 11 adjacent to the cylindrical portion 152 and adjacent to the cylindrical portion 152 in the axial direction of the cylindrical portion 152; Adjacent to portion 152 is an outer labyrinth portion 154 that widens radially inward toward rotor shaft 11 .

A plurality of inner labyrinth teeth 153 a are attached to the surface of the inner labyrinth portion 153 facing the rotor shaft 11 , and are spaced apart from each other in the axial direction. A plurality of outer labyrinth teeth 154a are attached to the surface of the outer labyrinth portion 154 that faces the rotor shaft 11 and are spaced apart from each other in the axial direction. The number of outer labyrinth teeth 154 a is greater than the number of inner labyrinth teeth 153 a so that the flow resistance of sealing air in outer labyrinth portion 154 is greater than the flow resistance of sealing air in inner labyrinth portion 153 . is formed in

A seal structure space 155 is formed by the cylindrical portion 152 , the inner labyrinth portion 153 , the outer labyrinth portion 154 and the rotor shaft 11 .

The partition plate 161 has a perforated disc shape and is attached to a portion of the rotor shaft 11 facing the seal structure space 155 . The radial outer edge of the partition plate 161 forms a clearance between the radial inner surface of the cylindrical portion 152 and the rotor shaft 11 and the outer oil thrower 150 due to manufacturing errors, assembly errors, vibrations during operation, and the like. The gap size is set to be larger than the relative positional deviation in the radial direction with the

The partition plate 161 partitions the seal structure space 155 into an inner space 155a and an outer space 155b in the axial direction. The axial position of the partition plate 161 is set so that the axial widths of the inner space 155a and the outer space 155b are approximately the same. Here, when the width of the outer space 155b in the axial direction becomes narrower than a certain amount, the effect of pushing out water entering the outer space 155b from the outside of the outer labyrinth portion 154 via the outer labyrinth portion 154 causes the water to gradually , enters the inner space 155a from the outer space 155b. Therefore, the width of the outer space 155b in the axial direction is set to a width that does not produce the pushing effect. The same applies to the inner space 155a.

The inner air supply section 171 and the outer air supply section 172 are connected to supply sealing air to the inner space 155a and the outer space 155b, respectively. The outer air supply portions 172 are provided at two locations in the circumferential direction, for example, at positions Θ1 in the clockwise direction and Θ2 in the counterclockwise direction when viewed from the top of the cylindrical portion 152 as shown in FIG. ing. Θ1 and Θ2 are, for example, about 60 degrees. The number of installations may be, for example, one at the vertex of the cylindrical portion 152, or three or more in the upper half. The same applies to the inner air supply section 171 . In addition, the inner air supply section 171 and the outer air supply section 172 may be provided so that they are installed at different locations and in different numbers.

FIG. 5 is a partial cross-sectional view showing the details of the shaft penetration portion seal structure 200 in the range indicated by B in FIG. 2 of the bearing structure 100 of the rotary electric machine 300 according to the first embodiment.

FIG. 5 shows the bottom side of the shaft-penetration portion seal structure 200, and the structure on the discharge side of sealing air and moisture entering from the outside is different from the structure shown in FIG.

The inner discharge part 173 and the outer discharge part 174 are connected to discharge seal air and moisture entering from the outside from the inner space 155a and the outer space 155b, respectively. As shown in FIG. 3, the outer discharge portions 174 are provided in the circumferential direction, for example, at five locations near the bottom as shown in FIG. The number of installations may be 4 or less or 6 or more in the lower half. The same applies to the inner discharge portion 173 . In addition, the inner discharge part 173 and the outer discharge part 174 may be provided so as to be different from each other in installation location and installation number.

The operation of this embodiment configured as above will be described.

First, consider a case where the rotating electrical machine 300 is in a stopped state, that is, the rotor shaft 11 is not rotating. Moisture entering the outer space 155b from the outside of the outer labyrinth portion 154 via the outer labyrinth portion 154 is prevented from entering the inner space 155a by the partition plate 161. It moves downward along the inner surface of the portion 152 and is discharged from the outer discharge portion 174 .

Also, even if it goes over the partition plate 161 and enters the inner space 155 a , it similarly moves downward along the surface of the rotor shaft 11 or the inner surface of the cylindrical portion 152 and is discharged from the inner discharge portion 173 . be done.

Next, consider a case where the rotating electrical machine 300 is in an operating state, that is, the rotor shaft 11 is in a rotating state. In this case, the water entering the outer space 155b from the outside of the outer labyrinth portion 154 via the outer labyrinth portion 154 is caused by the centrifugal force caused by the rotation of the rotor shaft 11 to move the surface of the rotor shaft 11 or the partition plate 161. After being thrown radially outward from the side surface on the outer space 155 b side and adhering to the inner surface of the cylindrical portion 152 , it moves downward along the inner surface of the cylindrical portion 152 and is discharged from the outer discharge portion 174 . In addition, the rotation of the partition plate 161 substantially prevents the movement of the user to climb over the partition plate 161 and enter the inner space 155a.

As described above, according to the present embodiment, the sealing performance can be enhanced without excessively reducing the clearance in the labyrinth of the sealing portion.

[Second embodiment]
FIG. 6 is a partial cross-sectional view showing details of the shaft penetration portion seal structure 200a of the bearing structure 100 of the rotary electric machine 300 according to the second embodiment.

The second embodiment is a modification of the first embodiment. The shaft penetration portion seal structure 200 a in this embodiment has a plurality of inner wings 181 attached to the inner surface of the partition plate 161 and a plurality of outer wings 182 attached to the outer surface of the partition plate 161 .

The plurality of inner blades 181 are arranged at equal intervals in the circumferential direction. A plurality of outer wings 182 are similarly arranged at equal intervals in the circumferential direction. The number of inner wings 181 and the number of outer wings 182 may be the same or different.

The position where the inner blade 181 is attached to the partition plate 161 in the radial direction is the innermost position in the radial direction. Also, the angle at which the inner blade 181 is attached to the partition plate 161 in the radial direction is parallel to the axial direction. However, it may be angled in the axial direction. In that case, by forming an acute angle on the side facing the direction of rotation, the efficiency of retaining moisture and expelling it in the radial direction is improved.

As described above, especially when the rotor 10 is in a rotating state, it is possible to improve the moisture intrusion suppression effect.

[Third Embodiment]
FIG. 7 is a partial cross-sectional view showing the details of the shaft penetration portion seal structure 200b of the bearing structure of the rotary electric machine according to the third embodiment.

The third embodiment is a modification of the first embodiment. The shaft penetration portion seal structure 200 b in this embodiment has a lower groove 191 formed in a lower portion of the cylindrical portion 152 and at an axial position corresponding to the partition plate 161 .

By having the lower groove 191 , it is possible to avoid a situation in which the moisture is rolled up due to the rotation of the partition plate 161 before the moisture is discharged from the lower part of the cylindrical portion 152 .

[Other embodiments]
Although the embodiments of the present invention have been described above, the embodiments are presented as examples and are not intended to limit the scope of the invention.

Moreover, you may combine the characteristic of each embodiment. In addition, the embodiments can be implemented in various other forms, and various omissions, replacements, and modifications can be made without departing from the scope of the invention.

The embodiments and their modifications are included in the scope and spirit of the invention, as well as the scope of the invention described in the claims and its equivalents.

DESCRIPTION OF SYMBOLS 10... Rotor, 11... Rotor shaft, 12... Rotor core, 13... Rotor bar, 15... Inner fan, 20... Stator, 21... Stator core, 22... Stator winding, 30... Frame, 31 In-frame flow path 32 Flow path inlet 33 Flow path outlet 40 Bearing bracket 100 Bearing structure 110 Bearing body 120 Bearing pad 130 Bearing cap 140 Inner oil drainer 150 Outer oil slinger 151 Support plate 152 Cylindrical part 153 Inner labyrinth part 153a Inner labyrinth tooth 154 Outer labyrinth part 154a Outer labyrinth tooth 155 Seal structure space 155a Inner space 155b... Outer space 161... Partition plate 171... Inner air supply part 172... Outer air supply part 173... Inner discharge part 174... Outer discharge part 181... Inner wing 182... Outer wing 191... Lower groove , 200, 200a, 200b... Shaft penetration portion seal structure 300... Rotating electric machine

Claims (6)

A bearing structure for rotatably supporting a rotor shaft of a rotating electrical machine,
a bearing body that directly supports the rotor shaft;
a shaft through portion seal structure provided on the opposite side of the rotor core in the axial direction when viewed from the bearing main body;
and
The shaft penetrating portion seal structure includes:
an inner labyrinth;
an outer labyrinth portion;
a seal structure space formed by the inner labyrinth portion and the outer labyrinth portion;
a partition plate attached to the rotor shaft and formed to partition the seal structure space into an inner space and an outer space in the axial direction;
an inner air supply section and an outer air supply section that supply seal air to the inner space and the outer space, respectively;
A bearing structure comprising: 2. The bearing structure according to claim 1, wherein the flow resistance of the sealing air in the outer labyrinth portion is greater than the flow resistance of the sealing air in the inner labyrinth portion. The shaft penetrating portion seal structure includes:
a plurality of inner labyrinth teeth provided radially inward of the inner labyrinth portion;
a plurality of outer labyrinth teeth provided radially inward of the outer labyrinth portion;
has
3. The bearing structure according to claim 1, wherein the number of said outer labyrinth teeth is greater than the number of said inner labyrinth teeth. The bearing structure according to any one of claims 1 to 3, wherein the shaft penetration portion seal structure further includes a plurality of blades attached to the partition plate. The shaft penetrating portion seal structure includes:
a support plate that is supported stationary and has an opening in the center;
a cylindrical portion connected to the opening in the support plate and extending axially, the inner portion of which adjoins the inner labyrinth portion and the outer portion of which adjoins the outer labyrinth portion;
further having
A lower groove is formed in a portion corresponding to the partition plate at the lower portion of the cylindrical portion,
5. The bearing structure according to any one of claims 1 to 4, characterized in that: a rotor having an axially extending rotor shaft and a rotor core mounted radially outwardly of the rotor shaft;
a stator having a stator core disposed radially outward of the rotor core; and a stator winding axially penetrating through the stator core;
two bearing structures that are stationary supported and rotatably support the rotor shaft on both axial sides of the rotor core;
a frame disposed radially outward of the stator;
two bearing brackets attached to opposite ends of the frame to support each of the two bearing structures;
A rotating electrical machine comprising
at least one of the two bearing structures,
a bearing body that directly supports the rotor shaft;
a shaft penetration portion seal structure provided on the opposite side of the rotor core in the axial direction when viewed from the bearing main body and suppressing intrusion of outside air and moisture into the bearing main body;
and
The shaft penetrating portion seal structure includes:
an inner labyrinth;
an outer labyrinth portion; a seal structure space formed by the inner labyrinth portion and the outer labyrinth portion;
a partition plate attached to the rotor shaft and formed to partition the seal structure space into an inner space and an outer space in the axial direction;
an inner air supply section and an outer air supply section that supply seal air to the inner space and the outer space, respectively;
A rotating electric machine characterized by having:

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