JP7273612B2 - Bearing structure and rotating electric machine - Google Patents

Description

The present invention relates to a bearing structure and a rotating electrical machine having the same.

A rotating electrical machine includes a rotor having a rotor shaft and a rotor core attached to the rotor shaft, and a stator having a stator core and stator windings extending therethrough. The rotor shaft is rotatably supported by bearings on both sides of the rotor core. As bearings, for example, bearing bodies or sliding bearings are generally used.

For lubrication of bearings, there are a method of supplying liquid lubricating oil and a method of supplying gel grease. In the case of sliding bearings, it is usually configured to always supply lubricating oil. On the other hand, in the case of the bearing main body, grease is often replenished periodically.

JP-A-5-149344

As described above, the method of supplying grease requires periodic injection of grease from the outside.

On the other hand, there are facilities such as air conditioners that cannot be stopped while the plant is in operation. If the electric motor is located in the air conditioning duct, the electric motor cannot be accessed while the air conditioning installation is in operation. Thus, during operation of the plant, it is necessary to maintain the lubricating function of the grease even when the rotating electrical machine is installed in a location with limited or no access.

As a method for reducing the amount of grease supplied, there is known a technique of providing an impeller, for example, for draining oil in order to reduce leakage from the labyrinth (see Patent Document 1). However, it does not solve the problem of securing the necessary supply amount.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to ensure a lubricating function with grease even when a rotary electric machine is installed in an inaccessible location.

In order to achieve the above object, a rotating electric machine according to the present invention includes a rotor having a rotor shaft extending in a direction of a rotation axis, a rotor iron core provided radially outside the rotor shaft, and the rotor a stator having a cylindrical stator core provided radially outside the core; a stator winding penetrating through the stator core in the direction of the rotating shaft; a frame arranged to house the rotor core and the stator; and two bearing structures that sandwich the rotor core and rotatably support the rotor shaft on both sides in the direction of the rotation axis, each of the two bearing structures has a bearing body, a bearing support portion that supports the bearing body stationary, and a flat plate portion that extends radially outward of the bearing support portion from the bearing support portion; a bearing bracket in which an injection portion for injecting grease for lubricating the bearing main body from the outside is formed in the flat plate portion , and a passage communicating between the injection portion and the bearing main body is formed in the bearing support portion ; a storage portion that communicates with the passage and stores the grease, the passage being formed between a transfer portion that communicates with the injection portion and the bearing main body; a melting section positioned inside the machine and aligned with the bearing main body in the direction of the rotation axis, receiving heat due to heat conduction from the bearing main body, and melting the grease from the injection section and the storage section by the heat; , is characterized by having

Further, a bearing structure according to the present invention includes a rotor having a rotor shaft extending in a direction of a rotation axis, a rotor iron core provided radially outside the rotor shaft, and a rotor core radially outside the rotor iron core. A stator having a cylindrical stator core provided therein, a stator winding passing through the stator core in the direction of the rotation axis, and the rotor arranged radially outside the stator. A bearing structure for rotatably supporting the rotor shaft at both sides in the direction of the rotation axis with the rotor core of the rotor shaft of a rotating electric machine provided, comprising a frame housing an iron core and the stator. a bearing main body, a bearing support portion that supports the bearing main body stationary, and a flat plate portion that extends radially outward of the bearing support portion from the bearing support portion; a bearing bracket in which an injection part into which grease for lubrication can be injected is formed in the flat plate part , and a passage communicating between the injection part and the bearing main body is formed in the bearing support part; a storage section for storing the grease, wherein the passage is formed between the transfer section communicating with the injection section and the bearing main body, and is located inside the bearing main body. a melting portion that is positioned in parallel with the bearing main body in the direction of the rotation axis, receives heat due to heat conduction from the bearing main body, and melts the grease from the injection portion and the storage portion by the heat. and

ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to ensure the lubricating function by grease, even when it installs in the place which a rotary electric machine cannot access.

1 is a longitudinal sectional view showing the configuration of a rotating electric machine according to a first embodiment; FIG. 2 is a side view taken along the line II-II in FIG. 1, showing the configuration of the bearing structure according to the first embodiment; FIG. FIG. 3 is a horizontal cross-sectional view taken along line III-III in FIG. 2, showing the configuration of the bearing structure according to the first embodiment; FIG. 3 is a vertical cross-sectional view taken along line IV-IV in FIG. 2 showing the configuration of the bearing structure according to the first embodiment; FIG. 8 is a conceptual partial elevational cross-sectional view for explaining details of a storage portion of a bearing structure and a state of grease according to a second embodiment; FIG. 11 is a conceptual partial elevational cross-sectional view for explaining details of a storage portion and a state of grease in a bearing structure according to a third embodiment; FIG. 11 is a conceptual partial elevational cross-sectional view for explaining details of a storage portion of a bearing structure and a state of grease according to a fourth embodiment;

Hereinafter, a bearing structure and a rotating electric machine according to embodiments of the present invention will be described with reference to the drawings. Here, parts that are the same or similar to each other are denoted by common reference numerals, and repeated explanations are omitted.

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

A rotating electric machine 200 has a rotor 10 , a stator 20 , a frame 40 and two bearing structures 100 . Note that the detailed illustration of the bearing structure 100 is omitted in FIG.

The rotor 10 has a rotor shaft 11 extending in the rotation axis direction and a rotor core 12 attached to the rotor shaft 11 .

The stator 20 has a stator core 21 arranged radially outside of the rotor core 12 to surround the rotor core 12 with an air gap 18 interposed therebetween, and a stator winding 22 penetrating the stator core 21 . .

Rotor core 12 and stator 20 are housed within frame 40 . The bearing brackets 120 of the bearing structure 100 are attached to both ends of the frame 40 . The bearing bracket 120 has a flat plate portion 121 that extends radially outwardly of the bearing support portion 128 that directly supports the bearing main body 110 ( FIG. 3 ) and that is coupled to the frame 40 .

The frame 40 and the two bearing structures 100 form a closed space 40a together. Hereinafter, the side facing the closed space 40a will be referred to as the inside of the machine, and the side facing the outside air will be called the outside of the machine.

2 is a side view taken along the line II-II in FIG. 1 showing the configuration of the bearing structure according to the first embodiment, and FIG. 3 is a cross-sectional view taken along the line III-III in FIG. 4 is a sectional view taken along line IV-IV in FIG.

As shown in FIG. 3 , each bearing structure 100 has a bearing body 110 , a bearing bracket 120 , a housing 130 and an exhaust 140 .

The bearing body 110 has a plurality of rotating bodies 111 , rotating portions 112 and stationary portions 113 . The rotating part 112 is attached to the rotor shaft 11 . The stationary portion 113 is stationary supported by the bearing support portion 128 of the bearing bracket 120 so as to face the rotating portion 112 . A plurality of rotating bodies 111 arranged in the circumferential direction are sandwiched between the rotating portion 112 and the stationary portion 113 and rotate together with the rotation of the rotating portion 112 .

The bearing bracket 120 has a flat plate portion 121 and a bearing support portion 128 that directly supports the bearing body 110 .

As shown in FIG. 2 , the flat plate portion 121 is an annular disk, and is connected to a bearing support portion 128 on the radially inner side. Flat plate portion 121 is connected to frame 40 by a plurality of connecting members 121a such as bolts.

As shown in FIG. 3, the bearing support portion 128 stationary supports the stationary portion 113 of the bearing body 110 . A passage 126 for guiding grease to the bearing body 110 is formed inside the bearing support portion 128 . That is, the transfer portion 122 and the fusion portion 123 between the transfer portion 122 and the bearing main body 110 are formed as the passage 126 . A discharge port 125 is formed on the downstream side of the bearing body 110 . A portion of the passage 126 on the inside of the machine is formed in an annular shape.

One injection path 129 a of the injection portion 129 is formed in the flat plate portion 121 . The injection path 129a is formed to extend in the radial direction, and penetrates to the uppermost end face in the radial direction of the flat plate portion 121 . It communicates with the passage 126 of the bearing support 128 radially inward. A through hole of the injection path 129a on the radially outer end surface of the flat plate portion 121 is sealed with a grease nipple 129b. When injecting grease, for example, a grease injection cartridge (not shown) is connected to grease nipple 129b and the grease is press-fitted. Although the injection part 129 does not have to be provided vertically above the transfer part 122, it is formed in the angular direction in which the passage 126 is formed.

The discharge port 125 is disposed on the opposite side of the passage 126 across the bearing body 110 and communicates with a discharge portion 140 provided outside the machine. In addition, the discharge part 140 and the passage 126 are isolated. The grease discharged from discharge portion 140 is directly collected, for example, in a receiving container (not shown).

Thus, the transfer section 122 is formed so as to communicate with the injection section 129, and communicates with the melting section 123 inside the apparatus. An intermediate area exists between the transfer section 122 and the melting section 123, and the boundary between the transfer section 122 and the melting section 123 is conceptual.

A storage section 130 for storing grease is provided inside the machine so as to communicate with the passage 126 . The storage portion 130 has a storage container 131 and a communication portion 134 that allows the storage container 131 and the passage 126 to communicate with each other. Moreover, the upper part of the storage container 131 is opened and a lid 135 is attached.

A storage space 130 s is formed by the storage container 131 and the lid 135 of the storage section 130 . Here, the outer shape of the storage container 131 may be, for example, a cylinder or rectangular parallelepiped, or an elliptical or polygonal cross section. Moreover, it is not necessary to have the same cross section along the vertical direction. In addition, although the storage container 131 and the communication portion 134 extend vertically along the vertical direction, the present invention is not limited to this. That is, if the grease in the storage container 131 is subjected to a vertically downward component of gravity, the grease may be tilted with respect to the vertical direction.

The maximum volume of the storage space 130s in the storage container 131 is large enough to accommodate the amount of grease used over a predetermined period of time, for example, a period exceeding two years.

Next, the operation of this embodiment will be described.

During an open inspection of the rotating electric machine 200, the lid 135 of the storage container 131 can be removed and the storage container 131 can be filled with grease.

During operation of rotating electric machine 200, the temperature inside the machine rises, and the temperature of a portion of transfer section 122 that is close to the inside of the machine rises. The melting portion 123 is arranged inside the machine and receives heat by heat conduction from the bearing main body 110 having a high temperature due to frictional resistance heat. This heat causes the grease to become completely liquid. Therefore, in a region near bearing body 110 , for example, melted portion 123 , the grease is completely melted and supplied to bearing body 110 . In the storage space 130s, the gel-like grease becomes a sol as it approaches the melting portion 123 and the bearing main body 110 from the transfer portion 122, and is supplied to the bearing main body 110 by natural fall.

Further, when the grease is press-fitted from the injection part 129, the pressure in the storage space 130s in the storage container 131 of the storage part 130 originally exists in the storage space 130s because the storage space 130s is filled with the grease. Air pressure rises. This increased pressure serves as a driving force for pushing out the grease stored in the storage container 131 .

The grease supplied to bearing body 110 contributes to lubrication between rotating body 111 and rotating part 112 and between rotating body 111 and stationary part 113 of bearing body 110 , and then is discharged from discharging part 140 .

Since the volume of the storage space 130s is larger than the volume corresponding to the amount of grease consumed over the operating period of the rotary electric machine 200, for example, the maximum periodical inspection interval, the necessary grease is supplied.

Also, if necessary, grease can be supplied directly from the outside. When a grease injection cartridge is connected to the grease nipple 129b of the injection portion 129 and the grease is press-fitted, the grease is supplied to the bearing main body 110 via the passage 126 because there is a gap in the bearing main body 110. be. Although part of it moves to the storage container 131 side, the amount of migration is small because the storage container 131 side is a closed space.

If there is ample space inside the aircraft, it is advantageous in terms of layout and passageability in terms of the number of items occupying the space outside the aircraft. Further, since the storage portion 130 is provided inside the machine, which has a higher temperature than the outside, the grease stored in the storage portion 130 is liquefied in the container and reliably supplied to the bearing main body 110 .

Of the two bearing structures 100 shown in FIG. 1, the right bearing structure 100 in FIG. 1 has been described above, but the left bearing structure 100 is the same.

As described above, according to the present embodiment, even if the rotating electric machine is installed in a place where access is restricted during operation of the plant, or where access is not possible, during shutdown of the plant such as periodic inspection, etc. By entering and injecting grease, the necessary lubrication can be ensured during operation of the rotating electrical machine. Moreover, even when a large number of electric rotating machines are installed and operated like in a large plant such as a power plant, the frequency of supplying grease is reduced, thereby reducing the burden on operating personnel or maintenance personnel.

[Second embodiment]
FIG. 5 is a conceptual partial elevational cross-sectional view for explaining the details of the storage portion of the bearing structure and the state of the grease according to the second embodiment.

The second embodiment is a modification of the first embodiment. A storage unit 130 in the second embodiment has a cylinder 132 instead of the storage container 131 in the first embodiment. Other points are the same as the first embodiment.

Cylinder 132 is cylindrical and has a cross section of constant shape and dimension along its length. The cross section is, for example, rectangular, but may alternatively be non-rectangular. The cylinder 132 has therein a piston 133a that vertically divides the inside of the cylinder 132 and a spring 133b that pushes the piston 133a downward. A piston shaft (not shown) may be provided as required. A storage space 130 s in the cylinder 132 communicates with the communicating portion 134 .

The piston 133a is formed to be movable in the axial direction of the cylinder 132 along the inner wall of the cylinder 132 while its outer edge is in contact with the inner wall of the cylinder 132 . The spring 133b can drive the piston 133a over the entire length of the cylinder 132 . That is, when the storage space 130s is filled with grease, the spring 133b is in a compressed state. As the amount of grease decreases, the spring 133b acts to push down the piston 133a according to its volume, and the piston 133a is in a compressed state over all positions. It is in.

To fill the storage space 130s with grease, remove the lid 135 attached to the top of the cylinder 132, remove the spring 133b and the piston 133a, and then supply the grease to the storage space 130s from above. This can be done by restoring 133b and lid 135. FIG.

As described above, according to the present embodiment, it is possible to obtain means for further ensuring the pushing force of the grease stored in the storage space 130s.

[Third embodiment]
FIG. 6 is a conceptual partial elevational cross-sectional view for explaining the details of the storage portion of the bearing structure and the state of the grease according to the third embodiment.

The third embodiment is a modification of the first embodiment. In the third embodiment, the storage portion 130 is attached to the outboard portion of the bearing support portion 128 of the bearing bracket 120 . That is, the storage section 130 is provided outside the machine. Other than this, it is the same as the first embodiment.

This embodiment is advantageous when there is no space inside the machine.

[Fourth embodiment]
FIG. 7 is a conceptual partial elevational cross-sectional view for explaining the details of the storage portion of the bearing structure and the state of the grease according to the fourth embodiment.

The fourth embodiment is a combination of the second embodiment and the third embodiment. That is, the storage portion 130a is arranged outside the machine, and the storage portion 130a has a piston 133a and a spring 133b in the cylinder 132, so that the grease can be reliably supplied.

[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.

For example, in the first and second embodiments, the storage portion itself may be detachably attached to the bearing bracket, thereby removing the injection portion.

Moreover, you may combine the characteristic of each embodiment. For example, the features of the third embodiment may be combined with the first or second embodiment.

Furthermore, the embodiments can be implemented in various other forms, and various omissions, replacements, and modifications can be made without departing from the gist 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, 18... Gap, 20... Stator, 21... Stator core, 22... Stator winding, 40... Frame, 40a... Closed space, 100... Bearing Structure 110 Bearing body 111 Rotating body 112 Rotating part 113 Stationary part 120 Bearing bracket 121 Flat plate part 121a Combined body 122 Transfer part 123 Melting part 125 Exhaust Outlet 126 Passage 128 Bearing support 129 Injection part 129a Injection path 129b Grease nipple 130, 130a Storage part 130s Storage space 131 Storage container 132 Cylinder 133a Piston 133b Spring 134 Communicating portion 135 Lid 140 Discharging portion 200 Rotating electric machine

Claims (6)

a rotor having a rotor shaft extending in a rotation axis direction and a rotor iron core provided radially outside the rotor shaft;
a stator having a cylindrical stator core provided radially outward of the rotor core, and a stator winding penetrating through the stator core in the direction of the rotation axis;
a frame disposed radially outside the stator and housing the rotor core and the stator;
two bearing structures that sandwich the rotor core and rotatably support the rotor shaft on both sides in the direction of the rotation axis;
with
Each of the two bearing structures includes:
a bearing body;
It has a bearing support portion that supports the bearing body stationary and a flat plate portion that extends radially outward of the bearing support portion from the bearing support portion, and grease for lubricating the bearing body can be injected from the outside. a bearing bracket having an injection portion formed in the flat plate portion and a passage communicating between the injection portion and the bearing body formed in the bearing support portion ;
a storage unit that communicates with the passage and stores the grease;
and
The passage is
a transfer section in communication with the injection section;
is formed between the transfer portion and the bearing body, is positioned on the inside of the bearing body, is aligned with the bearing body in the direction of the rotating shaft, receives heat due to heat conduction from the bearing body, and receives heat from the bearing body; a melting section that melts the grease from the section and the storage section by the heat;
A rotating electric machine characterized by having: 2. The electric rotating machine according to claim 1, wherein the storage portion is provided inside the machine. 2. The rotary electric machine according to claim 1, wherein the storage portion is provided outside the machine. 4. The electric rotating machine according to claim 1, further comprising a discharge portion connected to the grease discharge side of the bearing body. The storage unit is
a cylinder containing the grease;
a piston provided within the cylinder;
a spring that pushes the grease in the cylinder into the passage by pushing the piston;
The rotary electric machine according to any one of claims 1 to 4, characterized by comprising: a rotor having a rotor shaft extending in the direction of the rotation axis; a rotor core provided radially outside the rotor shaft; and a cylindrical stator core provided radially outside the rotor core. a stator having a stator winding passing through the stator core in the direction of the rotation axis; and a frame arranged outside the stator in the radial direction to accommodate the rotor core and the stator. and a bearing structure that rotatably supports the rotor shaft at both sides in the direction of the rotation axis with the rotor iron core of the rotor shaft of a rotating electric machine interposed therebetween,
a bearing body;
It has a bearing support portion that supports the bearing body stationary and a flat plate portion that extends radially outward of the bearing support portion from the bearing support portion, and grease for lubricating the bearing body can be injected from the outside. a bearing bracket having an injection portion formed in the flat plate portion and a passage communicating between the injection portion and the bearing body formed in the bearing support portion ;
a storage unit that communicates with the passage and stores the grease;
and
The passage is
a transfer section in communication with the injection section;
is formed between the transfer portion and the bearing body, is positioned on the inside of the bearing body, is aligned with the bearing body in the direction of the rotating shaft, receives heat due to heat conduction from the bearing body, and receives heat from the bearing body; a melting section that melts the grease from the section and the storage section by the heat;
A bearing structure comprising:

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