JP6983140B2 - Rotating machine and bearing structure - Google Patents

Description

The present invention relates to a rotary electric machine and a bearing structure thereof.

A rotary electric machine typically has a rotor shaft extending axially, a rotor having a rotor core attached radially outward, and a stator core and a stator core provided radially outside the rotor core. It is provided with a stator having a stator winding that penetrates the radially inner portion in the axial direction. The rotor shaft is rotatably supported on both sides of the rotor shaft in the axial direction by bearings.

Japanese Unexamined Patent Publication No. 2016-103871

In order to prevent oil leakage from the bearing portion, for example, an oil drain is provided adjacent to the bearing portion. A labyrinth seal may be formed on the oil drain (Patent Document 1).

The labyrinth seal structure in this bearing portion is formed between the member on the rotating side and the member on the fixed side, but since there is a gap between the member on the rotating side and the member on the fixed side, there is a gap. If there is a pressure difference, it is difficult to completely stop the leak.

Therefore, an object of the present invention is to provide a bearing structure having less leakage of lubricating oil in a rotary electric machine.

In order to achieve the above object, the rotary electric machine according to the present invention has a rotor having a rotor shaft extending in the axial direction, a rotor core attached to the radial outer side of the rotor shaft, and the rotor core. A stator having a stator core arranged radially outside and a stator winding that penetrates the inside of the stator core in the axial direction, and a stator that is statically supported and axially sandwiches the rotor core. Two bearing structures each having a bearing body that rotatably supports the rotor shaft on both sides of the rotor, a frame arranged radially outside the stator, and the two bearings attached to both ends of the frame. A rotary electric machine including a bearing bracket that supports each of the structures, wherein at least one of the two bearing structures is provided on the rotor main body and the rotor core side in the axial direction from the bearing main body. An inner oil drain and an outer oil drain provided on the opposite side of the rotor core side in the axial direction from the bearing body are provided, and the outside of the journal portion facing the radial inner surface of the bearing body in the rotor shaft. The diameter is formed to be smaller than the outer diameter of the large diameter portion adjacent to both sides of the journal portion in the axial direction, and the bearing body has a radial gap with the journal portion inside in the axial direction. body and the inner partition plate arranged Te, have a, a body outer partition plate disposed at a gap of the journal portion and the radially outer side of the axial direction, at least to the inner oil cut of the outer oil cut One has a first cylindrical portion arranged along the outer surface of the rotor shaft, and a journal-side throttle portion arranged axially on the bearing body side with a gap from the journal portion. , The journal-side throttle portion and the insertion portion having the second cylindrical portion are provided, and the second cylindrical portion is fitted with the first cylindrical portion in the axial direction with the first cylindrical portion. The relative positions of the journals are adjustable, and the journal-side throttles are spaced apart from the stepped surface perpendicular to the axis of rotation at the boundary between the journal and the large diameter portion. It is characterized by having a labyrinth tooth on the stepped surface side extending in the axial direction.

Further, the bearing structure according to the present invention is disposed of a rotor having a rotor shaft extending in the axial direction and a rotor core attached to the radial outer side of the rotor shaft, and a rotor shaft arranged on the radial outer side of the rotor core. A stator having a stator core and a stator winding that penetrates the inside of the stator core in the axial direction, a frame arranged radially outside the stator, and bearings attached to both ends of the frame. Two bearing structures that rotatably support the rotor shaft of a rotary electric machine including a bracket, and at least one of the two bearing structures is a bearing body and an axial rotor from the bearing body. It is provided with an inner oil drain provided on the iron core side and an outer oil drain provided on the opposite side of the rotor shaft side in the axial direction from the bearing body, and is provided with a radial inner surface of the bearing body in the rotor shaft. The outer diameter of the facing journal portion is formed to be smaller than the outer diameter of the large diameter portion adjacent in the axial direction, and the bearing body is arranged inside the axial direction with a radial gap from the journal portion. body and the inner partition plate which is, possess the body and the outer partition plate disposed at a gap of the journal portion and the radially outer side of the axial direction, the at least one of the outer oil cut and the inner oil clippers It has a first cylindrical portion arranged along the outer surface of the rotor shaft, and a journal-side throttle portion arranged axially on the bearing body side with a gap from the journal portion. An insertion portion having a journal-side throttle portion and a second cylindrical portion is provided, and the second cylindrical portion is fitted with the first cylindrical portion and is axially relative to the first cylindrical portion. The journal-side throttle portion is formed so as to be adjustable, and the journal-side throttle portion is arranged at a distance between a stepped surface perpendicular to the rotation axis at the boundary between the journal portion and the large-diameter portion. It is characterized by having labyrinth teeth on the stepped surface side extending in the direction.

According to the present invention, it is possible to provide a bearing structure having less leakage of lubricating oil in a rotary electric machine.

It is a vertical sectional view which shows the structure of the rotary electric machine which concerns on 1st Embodiment. It is the upper half vertical sectional view which shows the structure of the bearing structure of the rotary electric machine which concerns on 1st Embodiment. It is a vertical sectional view which shows the structure of the outer oil drain of the bearing structure of the rotary electric machine which concerns on 1st Embodiment. It is a vertical sectional view which shows the structure of the outer oil drain of the bearing structure of the rotary electric machine which concerns on 2nd Embodiment.

Hereinafter, the rotary electric machine and the bearing structure according to the embodiment of the present invention will be described with reference to the drawings. Here, common reference numerals are given to parts that are the same as or similar to each other, and duplicate description is omitted.

[First Embodiment]
FIG. 1 is a vertical sectional view showing a configuration of a rotary electric machine according to the first embodiment.

The rotary electric machine 300 has a rotor 10, a stator 20, a frame 40, two bearing brackets 45, and two bearing structures 100.

The rotor 10 has a rotor shaft 11 extending in the axial direction and a rotor core 12 attached to the radial outer side of the rotor shaft 11.

The stator 20 has a cylindrical stator core 21 arranged on the outer side of the rotor core 12 in the radial direction via a gap 18, and a stator winding 22 penetrating the inside of the stator core 21.

The frame 40 is provided on the radial outer side of the rotor core 12 and the stator 20 so as to surround them. Bearing brackets 45 are attached to both ends of the frame 40, respectively. Each bearing bracket 45 statically supports the bearing structure 100. The bearing structure 100 rotatably and statically supports the rotor shaft 11.

FIG. 2 is an upper half vertical cross-sectional view showing the configuration of the bearing structure of the rotary electric machine according to the first embodiment. Further, FIG. 3 is a vertical cross-sectional view showing the configuration of the outer oil drain of the bearing structure of the rotary electric machine according to the first embodiment. The inner oil drain 130 has the same configuration as the outer oil drain 140, but FIG. 3 shows only the configuration of the outer oil drain 140.

The bearing structure 100 has a bearing main body 110, a main body retainer 120, an inner oil drain 130, and an outer oil drain 140.

Here, the bearing structure 100 is provided to support the rotor shaft 11, but the portion of the rotor shaft 11 of the portion where the bearing structure 100 is provided has a step and is in a direction perpendicular to the rotation axis, that is, A stepped surface 11d is formed in the radial direction. That is, the rotor shaft 11 has a journal portion 11a having a relatively small diameter in the axial direction, a large diameter portion 11b having a diameter larger than that of the journal portion 11a on the inside, and a large diameter portion 11b on the outside in the axial direction. Has a large diameter portion 11c having a diameter relatively larger than that of the journal portion 11a.

The bearing main body 110 has a main body metal portion 111, an axial inner side of the main body metal portion 111, that is, a main body inner partition plate 113 attached to a side closer to the rotor core 12, and an axial outer side of the main body metal portion 111, that is. It has a main body outer partition plate 114 attached to the rotor core 12 on the far side.

The main body metal portion 111 has a substantially cylindrical shape, and its radial inner surface faces the radial outer side of the journal portion 11a, and is radially outer by the main body retainer 120 statically supported by the bearing bracket 45. Is supported by. On the radial outer side of the main body metal portion 111, the axial central portion protrudes radially outward, and the axial central portion is formed of a curved spherical surface portion 111a forming a part of a smooth spherical surface. The inner receiving seat 121a in the radial direction facing the main body metal portion 111 of the tubular portion 121 of the main body retainer 120 is formed in a shape corresponding to the main body metal portion 111.

A protective metal portion 112, which is a sliding member, is provided on the radial inner surface of the main body metal portion 111. The material of the protective metal portion 112 is an alloy for slide bearings (hereinafter, referred to as white metal) mainly composed of low melting point alloys such as lead, tin, antimony, and zinc.

Each of the main body inner partition plate 113 and the main body outer partition plate 114 attached to the axial end of the main body metal portion 111 surrounds the radial outside of the journal portion 11a and has a gap between the journal portion 11a and the journal portion 11a. It is formed in an annular shape so as to have. On the surface of the annular portion facing the journal portion 11a, a tooth portion provided on the entire circumference and extending in the radial direction may be provided. In this case, the length of the journal portion 11a in the axial direction is increased, and the rigidity of the rotor shaft 11 is reduced by that amount. Therefore, the range of the tooth portion is increased within a range in which the rigidity margin of the rotor shaft 11 is secured.

The body retainer 120 has a tubular portion 121, an inner annular portion 122, an outer annular portion 123, and a coupling annulus 124. The tubular portion 121 has a substantially cylindrical shape centered on a rotation axis, and as described above, a receiving seat 121a that supports the main body metal portion 111 from the outside in the radial direction is formed. The inner ring portion 122 is connected to the end portion of the tubular portion 121 on the rotor core side in the axial direction, and is connected to the inner oil drain 130 by a bolt or the like. The outer annulus portion 123 is connected to an end portion of the tubular portion 121 opposite to the rotor core side in the axial direction, and is connected to the outer oil drain 140 by a bolt or the like. The coupling ring 124 extends radially from the middle of the tubular portion 121 in the axial direction, and is coupled to the portion around the opening 45a of the bearing bracket 45 by a bolt or the like.

The inner oil drain 130 has a disk portion 131 that is coupled to the inner ring portion 122 of the main body retainer 120, a cylindrical portion 132, and a journal-side throttle portion 134. The cylindrical portion 132 extends axially along the radial surface of the large diameter portion 11b of the rotor shaft 11 from the opening portion of the disk portion 131. On the inner peripheral surface of the cylindrical portion 132, the large-diameter side drawing portions 133 are formed at intervals in the axial direction. The large-diameter side throttle portion 133 is annular and extends in the radial direction, and the inner diameter in the radial direction is larger by a predetermined gap on both sides due to the outer diameter of the large-diameter portion 11b of the rotor shaft 11. As a result, a labyrinth is formed on the inner surface of the cylindrical portion 132. The journal side drawing portion 134 overhangs from the opening portion of the disk portion 131 toward the journal portion 11a in the direction opposite to the cylindrical portion 132, and the tooth portion extending in the radial direction to the portion facing the outer surface of the journal portion 11a ( Not shown).

The outer oil drain 140 has a disk portion 141 connected to the outer ring portion 123 of the main body retainer 120, a cylindrical portion 142, and a journal-side throttle portion 144. The cylindrical portion 142 extends axially from the opening portion of the disk portion 141 along the radial surface of the large diameter portion 11c of the rotor shaft 11.

Large-diameter side diaphragm portions 143 are formed on the inner peripheral surface of the cylindrical portion 142 at intervals in the axial direction. The large-diameter side drawing portion 143 is annular and extends in the radial direction, and on the inner surface in the radial direction, the large-diameter labyrinth tooth 143a extending inward in the radial direction along the plane perpendicular to the rotation axis direction. Is attached. The diameter of the labyrinth tooth 143a on the large diameter side in the radial direction is larger than the outer diameter of the large diameter portion 11c of the rotor shaft 11 by a predetermined gap on both sides. As a result, a labyrinth is formed on the inner surface of the cylindrical portion 142.

The journal side drawing portion 144 overhangs from the opening portion of the disk portion 141 toward the journal portion 11a in the direction opposite to the cylindrical portion 142, and the journal side labyrinth tooth 144a is attached to the portion facing the outer surface of the journal portion 11a. ing. The diameter of the labyrinth tooth 144a on the journal side in the radial direction is larger than the outer diameter of the journal portion 11a of the rotor shaft 11 by a predetermined gap on both sides.

The case where the cylindrical portion 132 and the cylindrical portion 142 are arranged on the radial outer side of the large diameter portion 11b and the large diameter portion 11c of the rotor shaft 11, respectively, is shown, but the present invention is not limited to this. That is, part or all of it may be outside the journal portion 11a in the radial direction. In this case, the tooth portion (not shown) attached to the journal side throttle portion 134 on the radial outer side of the journal portion 11a and the journal side labyrinth tooth 144a attached to the journal side throttle portion 144 have their respective radial inner sides. It is formed so as to have a predetermined gap with the outer surface of the journal portion 11a.

The bearing body 110, the body retainer 120, the inner oil drain 130, and the outer oil drain 140 described above each have elements divided in the circumferential direction, and surround the rotor shaft 11. These elements are arranged on the outer side in the radial direction of the rotor shaft 11 and connected by bolts or the like to be integrated with each other.

In the bearing structure 100 according to the present embodiment configured as described above, the tooth portions formed in the openings of the main body inner partition plate 113 and the main body outer partition plate 114 of the main body metal portion 111 are the journal portion 11a. Have a predetermined gap between. In the conventional configuration, the main body inner partition plate 113 and the main body outer partition plate 114 are arranged outside the large diameter portions 11b and 11c of the rotor shaft 11. Therefore, assuming that the predetermined gap is equal to the conventional one, the flow path cross-sectional area of the gap portion as the route of leakage of the lubricating oil is the ratio of the outer diameter of the journal portion 11a to the outer diameters of the large diameter portions 11b and 11c. For example, it decreases to about 80% to 90%. As a result, in the bearing structure 100, first, the leakage of the lubricating oil from the bearing body 110 can be reduced.

As for the outer oil drain 140, all the throttle portions are conventionally arranged on the radial outside of the large diameter portion 11c, but in the present embodiment, the large diameter portion arranged on the radial outside of the large diameter portion 11c. In addition to the side throttle portion 143, a journal side throttle portion 144 arranged on the radial outer side of the journal portion 11a is formed. Similarly, for the inner oil drain 130, a journal-side throttle portion 134 arranged on the radial outer side of the journal portion 11a is formed.

Therefore, the annular area of a part of the labyrinth is reduced to, for example, about 80% to 90% of the conventional one.

As described above, according to the present embodiment, it is possible to provide the bearing structure 100 with less leakage of lubricating oil in the rotary electric machine 300.

[Second Embodiment]
FIG. 4 is a vertical cross-sectional view showing the configuration of the outer oil drain of the bearing structure of the rotary electric machine according to the second embodiment. The second embodiment is a modification of the first embodiment.

In the second embodiment, the outer oil drain 240 has a different configuration from the outer oil drain 140 in the first embodiment. Hereinafter, the outer oil drain 240 will be described as a representative, but the inner oil drain may also have the same configuration as the outer oil drain 240. In other respects, it is the same as the first embodiment.

The outer oil drain 240 has a disk portion 141, a cylindrical portion 242 (first cylindrical portion), and an insertion portion 244.

The insertion portion 244 is similar to the insertion portion 144 in the first embodiment in that it has a journal-side throttle portion 244a that overhangs from the large diameter portion 11c toward the journal portion 11a in the axial direction, but in the overhanging direction. Has a cylindrical portion 244b (second cylindrical portion) in the opposite direction.

Further, the journal-side throttle portion 244a is formed with a journal-side labyrinth tooth 244c extending in the radial direction so as to face the journal portion 11a of the rotor shaft 11, as in the first embodiment. The journal side throttle portion 244a is formed with a step surface side labyrinth tooth 244d extending in the axial direction so as to face the step surface 11d at the boundary between the journal portion 11a of the rotor shaft 11 and the large diameter portion 11c.

An annular hole 242a is formed in the cylindrical portion 242 of the outer oil drain 240 so as to fit with the cylindrical portion 244b of the insertion portion 244. As a result, the cylindrical portion 244b of the insertion portion 244 fitted with the annular hole 242a of the cylindrical portion 244b can adjust the mutual position in the axial direction. Further, the cylindrical portion 242 is formed with a screw hole 242b that penetrates radially outward from the annular hole 242a, and the cylindrical portion 244b of the insertion portion 244 fitted with the annular hole 242a of the cylindrical portion 244b by the set screw 242c. Can be held in place.

With the above configuration, the distance between the stepped surface side labyrinth tooth 244d provided on the journal side throttle portion 244a of the insertion portion 244 and the stepped surface 11d of the rotor shaft 11 can be set so as to have a predetermined gap.

As described above, in the second embodiment, a labyrinth having a predetermined gap can be formed also between the stepped surface 11d of the rotor shaft 11. Centrifugal force acts on the lubricating oil that leaks to the outside along the stepped surface 11d as the rotor shaft 11 rotates. Therefore, forming a labyrinth in this portion has a great effect on suppressing the leakage of the lubricating oil. Bring.

[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.

Furthermore, these embodiments can be implemented in various other embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the invention.

These embodiments and variations thereof are included in the scope of the invention described in the claims and the equivalent scope thereof, as are included in the scope and gist of the invention.

10 ... Rotor, 11 ... Rotor shaft, 11a ... Journal part, 11b, 11c ... Large diameter part, 11d ... Step surface, 12 ... Rotor core, 18 ... Gap, 20 ... Fixture, 21 ... Fixture core, 22 ... stator winding, 40 ... frame, 45 ... bearing bracket, 45a ... opening, 100 ... bearing structure, 110 ... bearing body, 111 ... body metal part, 111a ... spherical part, 112 ... protective metal part, 113 ... body Inner partition plate, 114 ... Main body outer partition plate, 120 ... Main body retainer, 121 ... Cylindrical part, 121a ... Receiving seat, 122 ... Inner ring part, 123 ... Outer ring part, 124 ... Bonding ring, 130 ... Inner Oil drain, 131 ... disk part, 132 ... cylindrical part 133 ... large diameter side drawing part, 134 ... journal side drawing part, 140 ... outer oil draining, 141 ... disk part, 142 ... cylindrical part, 143 ... diameter Most side squeezing part, 143a ... Large diameter side labyrinth tooth 144 ... Journal side squeezing part, 144a ... Journal side labyrinth tooth, 240 ... Outer oil drain, 242 ... Cylindrical part (first cylindrical part), 242a ... Circular Hole, 242b ... Screw hole, 242c ... Set screw, 244 ... Insertion part, 244a ... Journal side drawing part, 244b ... Cylindrical part (second cylindrical part), 244c ... Journal side labyrinth tooth, 244d ... Step surface side labyrinth tooth , 300 ... Rotating electric machine

Claims (2)

A rotor having a rotor shaft extending in the axial direction and a rotor core attached to the radial outer side of the rotor shaft.
A stator having a stator core arranged radially outside the rotor core and a stator winding that axially penetrates the inside of the stator core.
Two bearing structures that are statically supported and each have a bearing body that rotatably supports the rotor shaft on both sides of the rotor core in the axial direction.
A frame arranged radially outside the stator, and
Bearing brackets attached to both ends of the frame to support each of the two bearing structures,
It is a rotary electric machine equipped with
At least one of the two bearing structures
With the bearing body
The inner oil drain provided on the rotor core side in the axial direction from the bearing body,
The outer oil drain provided on the opposite side of the rotor core side in the axial direction from the bearing body,
Equipped with
In the rotor shaft, the outer diameter of the journal portion facing the radial inner surface of the bearing body is formed to be smaller than the outer diameter of the large diameter portion adjacent to both sides of the journal portion in the axial direction.
The bearing main body has a main body inner partition plate arranged with a radial gap from the journal portion on the inner side in the axial direction, and a main body arranged with a radial gap from the journal portion on the outer side in the axial direction. possess and outside the partition plate, the,
At least one of the inner oil drain and the outer oil drain
A first cylindrical portion arranged along the outer surface of the rotor shaft,
A journal-side throttle portion arranged on the bearing body side in the axial direction with a gap from the journal portion,
Have,
An insertion portion having the journal-side throttle portion and the second cylindrical portion is provided.
The second cylindrical portion is fitted with the first cylindrical portion so that the position relative to the first cylindrical portion in the axial direction can be adjusted.
The journal-side throttle portion has a step-side labyrinth tooth that is arranged at a distance between a step surface perpendicular to the rotation axis at the boundary between the journal portion and the large-diameter portion and extends in the axial direction.
A rotating electric machine characterized by that. A rotor having a rotor shaft extending in the axial direction and a rotor core attached to the radially outer side of the rotor shaft, a stator core arranged radially outside the rotor core, and the inside of the stator core. The rotor shaft of a rotary electric machine including a stator having a stator winding penetrating in the axial direction, a frame arranged radially outside the stator, and bearing brackets attached to both ends of the frame. Two bearing structures that rotatably support the
At least one of the two bearing structures
Bearing body and
The inner oil drain provided on the rotor core side in the axial direction from the bearing body,
The outer oil drain provided on the opposite side of the rotor core side in the axial direction from the bearing body,
Equipped with
In the rotor shaft, the outer diameter of the journal portion facing the radial inner surface of the bearing body is formed to be smaller than the outer diameter of the large diameter portion adjacent in the axial direction.
The bearing main body has a main body inner partition plate arranged with a radial gap from the journal portion on the inner side in the axial direction, and a main body arranged with a radial gap from the journal portion on the outer side in the axial direction. possess and outside the partition plate, the,
At least one of the inner oil drain and the outer oil drain
A first cylindrical portion arranged along the outer surface of the rotor shaft,
A journal-side throttle portion arranged on the bearing body side in the axial direction with a gap from the journal portion,
Have,
An insertion portion having the journal-side throttle portion and the second cylindrical portion is provided.
The second cylindrical portion is fitted with the first cylindrical portion so that the position relative to the first cylindrical portion in the axial direction can be adjusted.
The journal-side throttle portion has a step-side labyrinth tooth that is arranged at a distance between a step surface perpendicular to the rotation axis at the boundary between the journal portion and the large-diameter portion and extends in the axial direction.
A bearing structure characterized by that.

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