JP2017180503A - Sliding bearing and electric motor including sliding bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To sufficiently and entirely deliver lubricant to a bearing surface to maintain stable bearing performance and extend the life of a sliding bearing.SOLUTION: The sliding bearing supports a rotation shaft so as to be rotatable and allows slide movement of the rotation shaft at a bearing surface. The sliding bearing includes: a plurality of slide members extending in an insertion direction of the rotation shaft and provided in a circumferential direction at constant intervals at the bearing surface; and oil supply ports respectively provided intervals between the slide members.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a structure of a sliding bearing, and more particularly, to a technique effective when applied to an external pressure bearing for supplying lubricating oil pressurized from the outside to a bearing surface and lifting a shaft.

  In a slide bearing in which the shaft and the bearing relatively slide, a fluid lubricating film is generally formed between the shaft and the bearing, and the frictional resistance is reduced by the lubricating film to support the load. Sliding bearings are broadly divided into hydrodynamic bearings that generate a lubricating film by sliding movement and float the shaft by the film pressure and support it, and hydrostatic bearings that form a lubricating film using external fluid pressure. .

  A hydrostatic bearing with a structure that feeds fluid (generally lubricating oil) pressurized from the outside to the bearing surface and lifts the shaft, also called an external pressurized bearing, is used to send pressurized lubricating oil. Although equipment such as an oil pump and an oil tank is required, the friction loss is small, and the bearing surface does not come into solid contact even when starting and stopping, so there is little wear, and it is widely used in industrial equipment such as electric motors.

  As a background art in this technical field, there is a technique as described in Patent Document 1. Patent Document 1 states that “the amount of lubricating oil that is formed by combining a pair of semi-cylindrical bearings and that rotatably supports a shaft member and is supplied to the lower semi-cylindrical bearing. Is disclosed.

  Further, Patent Document 2 states that “a common sliding member can be used regardless of the outer diameter of the shaft to be supported, and versatility can be improved, and even if an uneven load or the like occurs during use, it is difficult to break. A “bearing structure” is disclosed.

JP2015-152107A JP 2013-44417 A

  By the way, in a hydrostatic bearing type slide bearing, the friction coefficient between the shaft and the bearing is governed by the oil pressure and the pressure receiving area of the fluid (lubricating oil) supplied from the outside, so that the lubricating oil can be distributed evenly over the bearing surface. This is an important issue for maintaining stable bearing performance and extending the life of plain bearings.

  For example, it is conceivable to provide an oil supply hole and an oil groove as in Patent Document 1 in the bearing structure of Patent Document 2. However, in this method, it is difficult to form a sufficient lubricating film on the entire bearing surface, and there is a problem that the oil is not sufficiently circulated.

  SUMMARY OF THE INVENTION Accordingly, the present invention has a stable bearing performance in a mixed lubrication and boundary lubrication region required in a lubrication environment, and an object thereof is to extend the life of a slide bearing.

  In order to solve the above-described problems, the present invention provides a sliding bearing that rotatably supports a rotating shaft and causes the rotating shaft to slide on the bearing surface, and the sliding bearing is disposed on the rotating shaft. A plurality of sliding members extending in the insertion direction are provided at predetermined intervals in the circumferential direction, and an oil filler opening is provided between each of the plurality of sliding members.

  Further, the present invention is an electric motor in which a coil and a core are mounted, and the rotating shaft is rotated by an induced current, and the rotating shaft is rotatably supported by a slide bearing, and the slide bearing is A plurality of sliding members extending in the circumferential direction at a predetermined interval are provided on the bearing surface at predetermined intervals in the circumferential direction, and an oil filler port is provided between each of the plurality of sliding members. It is characterized by.

  According to the present invention, it is possible to have a stable bearing performance in a mixed lubrication or boundary lubrication region required in a lubrication environment, and to extend the life of a slide bearing.

  Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.

It is a figure showing the whole electric motor outline concerning one embodiment of the present invention. It is an overhead view of the bearing metal which concerns on one Embodiment of this invention. It is sectional drawing which looked at the bearing metal from the A-A 'direction of FIG. It is sectional drawing which looked at the bearing metal from the C-C 'direction of FIG. It is a figure which shows notionally the D-D 'part cross section of FIG. 4A. It is a figure which shows the flow path of the bearing supply-and-discharge oil in the slide bearing which concerns on one Embodiment of this invention. It is a figure which shows the shape and sliding member of the oil lift part of the bearing metal which concern on one Embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings. In the drawings, the same components are denoted by the same reference numerals, and detailed description of overlapping portions is omitted.

  First, an electric motor to which the present invention is applied will be described with reference to FIG. FIG. 1 shows an overall outline of the electric motor. As shown in FIG. 1, the electric motor of the present embodiment is configured as an electric motor system in which a cooling device 2 is mounted on an electric motor 1. 1 is a view of the left view of FIG. 1 as viewed from the B-B ′ direction (minus X direction).

  A coil and a core are mounted on the electric motor main body (the central portion of the electric motor 1), and the shaft shaft 102 is rotated by an induced current. The shaft 102 is supported by two slide bearings (slide bearing body 101).

  The cooling device 2 is provided with a motor 3, a fan 4, and a cooling water circulation tank 5. The heat generated by the electric motor 1 is circulated by rotating the fan 4 by the motor 3, and heat exchange is performed by the cooling water circulation tank 5. By doing so, the electric motor 1 is cooled.

  Next, the internal structure of the plain bearing body 101 will be described with reference to FIG. A bearing metal shown in FIG. 2 is incorporated in the slide bearing main body 101. FIG. 2 is an overhead view of the bearing metal. The bearing metal is a component used as a bearing for the shaft shaft 102.

  As shown in FIG. 2, the bearing metal has a hollow structure, and functions as a bearing when the shaft 102 is inserted into the hollow region. A sliding member 311 is provided on the inner diameter side surface of the bearing metal from the back to the front of the paper. Further, oil supply ports 304, 308, and 310 for introducing oil into the bearing surface are provided on the inner diameter side surface of the bearing metal. The detailed configuration of the sliding member 311 and each oil filler will be described later with reference to FIG.

  FIG. 3 is a cross-sectional view taken along the line A-A ′ of FIG. 1, and shows a cross-sectional shape of only the bearing metal excluding the shaft 102. The bearing metal of this embodiment is a combination of the upper metal 301 and the lower metal 302.

  The inner diameter circle of the bearing metal that combines the upper metal 301 and the lower metal 302 is an inner diameter circle that matches the shaft diameter of the shaft shaft 102, and is a slide bearing that is made of a bearing alloy. The bearing alloy is an alloy mainly composed of tin (Sn), antimony (Sb), lead (Pb), or the like, generally called white metal.

  In the bearing metal of this embodiment, as shown in FIGS. 2 and 3, the sliding member 311 is incorporated in the lower metal 302. The sliding member 311 can prevent the upper metal 301 and the lower metal 302 from being damaged even if an unbalanced load or the like is generated by the shaft 102 during use.

  The sliding member 311 has a curved plate shape, and a groove is formed in the lower metal 302 in the axial direction (backward as viewed in FIG. 3), and the sliding member 311 is incorporated therein. It is. For the sliding member 311, for example, a member made of RB ceramics (RB: Rice Bran), which is a hard porous carbon material made from defatted rice bran, is used. Other materials may be used.

  The sliding member 311 is radially arranged on the inner side surface of the lower metal 302 in a symmetrical manner with respect to the Y axis, and is provided in an oil reservoir 305 provided in the vicinity of the first oil supply port 303 and the second oil supply port 304. They are arranged at a predetermined interval until they do not overlap. The oil reservoir 305 is a recess (concave portion) for storing oil introduced from the first oil supply port 303 and the second oil supply port 304.

  In FIGS. 2 and 3, the upper metal 301 is made of only a bearing alloy, and the sliding member 311 is not incorporated, but may be incorporated in the upper metal 301.

  Here, the reason why the sliding member 311 is incorporated in at least the lower metal 302 is that a large amount of unbalanced load or the like due to the shaft 102 is added to the lower metal 302, and wear resistance can be improved.

  The reason why the sliding member 311 is not incorporated in the upper metal 301 of FIGS. 2 and 3 in the bearing metal of this embodiment is mainly because a load is applied to the lower metal 302. The portion without the sliding member 311 is a bearing alloy.

  In FIG. 3, an oil supply port 306 at the lower center of the lower metal 302 is an oil supply port for supplying high-pressure oil, and is intended for an oil lift that floats the shaft 102 by hydraulic pressure. The other oil filler ports (the oil filler ports 303 to 304 and the third oil filler port 307 to the sixth oil filler port 310) are oil filler ports for supplying low-pressure oil. The oil supply ports 307 to 310 for supplying low-pressure oil are provided between the sliding members 311 so that the oil spreads over the entire bearing surface, that is, the entire inner diameter side surface of the lower metal 302.

  The arrangement of the oil supply ports 307 to 310 for supplying low-pressure oil is symmetrical with respect to the Y axis in FIG. Further, since the oil flows from the top to the bottom on the principle of gravity, it is desirable that the oil supply port is provided on the upper side (plus Y direction side) as much as possible.

  In addition, when only the sliding member 311 satisfies the lubrication condition of the bearing surface, it is not always necessary to provide an oil filler port between the sliding members 311.

  Further, the bearing metal portion in the vicinity of the oil supply port 306 for supplying high-pressure oil is not curved and is processed into a rectangular flat surface. The shape of the bearing metal in the vicinity of the high-pressure oil supply port 306 will be described in the second embodiment.

  4A is a cross-sectional view taken along the line C-C ′ of FIG. 3. The sliding member 401 is arranged to extend along the Z direction, that is, the insertion direction of the shaft 102. Here, the sliding member 401 composed of a plurality of members is attached to the inner diameter side surface of the lower metal 302 with an adhesive. In addition, the sliding member 401 is good also as a form which processes and forms an oil filler opening etc. in a required location using one member.

  The sliding member 401 is incorporated into the inner side surface of the lower metal 302 so that the bearing alloy is grooved and does not move even when an oil discharge pressure is applied by an adhesive and fitting.

  Note that sliding members 401 are also incorporated at both ends in the Z direction where oil supply ports 306 for supplying high-pressure oil are provided. Details of this configuration will be described in a second embodiment.

  FIG. 5 is a view showing a flow path of bearing supply / discharge oil to the slide bearing main body 101. By supplying oil (lubricating oil) from an oil supply port 501 provided in the bearing body, the oil flows to the bearing metal outer oil sump 502.

  Oil flows from the respective oil supply ports (the oil supply ports 303 to 304 and the oil supply ports 307 to 310 in FIG. 3) into the bearing metal due to the pressure difference between the inner side and the outer side oil sump 502 of the bearing metal. Supplying the high-pressure oil to the high-pressure oil supply port 306 is performed by branching a part of the oil supply system and supplying it by pressurizing with a pressurizing pump, or a supply system different from the oil supply system to other oil supply ports May be provided to supply high pressure oil.

  By processing the bearing alloy processed portion (within the range indicated by the dotted lines 402 and 403 in FIG. 4A) at both ends of the lower metal 302 a little wider than the diameter of the shaft 102, the oil flows outside the gap. The oil is discharged to the oil tank 504 of the main bearing body and flows to the oil discharge port 505.

  As described above, according to the slide bearing structure of the present embodiment, the lubricant can be sufficiently spread over the bearing surface, maintaining stable bearing performance and extending the life of the slide bearing. Become.

  The plain bearing of Example 2 is demonstrated using FIG. 4A and 4B. 4A is a cross-sectional view taken along the line C-C ′ of FIG. 3, and FIG. 4B is a cross-sectional view taken along the line D-D ′ of FIG. 4A. As described with reference to FIG. 3 of the first embodiment, the purpose of supplying oil from the high-pressure oil supply port 306 to the bearing surface is to float the shaft 102. If there is no sliding member 404 provided at the end portion in the Z direction shown in FIG. 4A, the oil flows in the Z axis direction and the purpose of floating the shaft 102 cannot be achieved.

  Therefore, the sliding member 401 blocks the oil supplied to the bearing surface from the high-pressure oil supply port 306 so that an oil sump can be made. That is, the damming portion (oil stop 404) is arranged so as to ensure a prescribed discharge pressure that enables the shaft shaft 102 to be lifted by the oil lift device.

  Further, the bearing metal portion in the vicinity of the high-pressure oil supply port 306 is not curved, and is processed into a rectangular (rectangular) plane. Even a bearing metal portion that has been processed into a rectangular (rectangular) plane has an oil sump function, but if a sliding member 404 provided at the end in the Z-axis direction is further provided, an efficient oil sump can be achieved and the shaft shaft 102 can be more effectively realized.

  The portion of the bearing alloy within the range of 402 to 403 in FIG. 4A is processed to be slightly larger than the diameter of the shaft 102 as shown in FIG. 4B. This limits the amount of oil drained. It is not a function to stop the flow of oil like a damming but a function to restrict. That is, in order to limit the amount of oil drained, both ends of the lower metal 302 in the shaft axial direction are processed to be slightly larger than the outer diameter of the shaft shaft 102 so that there is a gap between the shaft shaft and the bearing inner diameter. Yes.

  Note that if the inner diameter of the shaft 102 matches the diameter of the shaft 102, it is difficult to drain oil, and there is no other place where oil is drained. Further, if the inner diameter circle is larger than the diameter of the shaft 102, the oil may escape in the Z direction in FIG. 4A and the oil may not reach all the sliding members 401 (RB ceramic material). An oil sump function is also included.

  According to the slide bearing structure of the present embodiment, as in the case of the first embodiment, the lubricant can be sufficiently distributed evenly on the bearing surface, maintaining stable bearing performance and extending the life of the slide bearing. It becomes.

  The plain bearing of Example 3 is demonstrated using FIG. FIG. 6 shows the shape of the sliding member 602 near the high-pressure oil supply port 603. The sliding member 602 adjacent to the high-pressure oil supply port 603 is chamfered (the chamfered portion 601), and has a large area so that a specified discharge pressure that allows the shaft shaft 102 to float can be secured. doing. This is because it is desired to increase as much as possible the area where the oil spreads while maintaining the sliding area by the sliding member 602 as much as possible. It should be noted that chamfering may be applied to the sliding member 602 other than the sliding member 602 adjacent to the high-pressure oil supply port 603.

  According to the slide bearing structure of the present embodiment, as in the first and second embodiments, the lubricating oil can be distributed evenly over the bearing surface, maintaining stable bearing performance and improving the length of the slide bearing. Life can be extended.

  In addition, this invention is not limited to an above-described Example, Various modifications are included. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Further, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

  DESCRIPTION OF SYMBOLS 1 ... Electric motor, 2 ... Cooling device, 3 ... Motor, 4 ... Fan, 5 ... Cooling water circulation tank, 101 ... Sliding bearing main body, 102 ... Shaft shaft, 301 ... Upper metal, 302 ... Lower metal, 303 ... 1st oil supply , 304: second oil supply port, 305 ... oil reservoir, 306, 603 ... high pressure oil supply port, 307 ... third oil supply port, 308, 604 ... fourth oil supply port, 309, 605 ... fifth oil supply port, 310, 606 ... Sixth oil supply port, 311, 401, 602 ... Sliding member, 402, 403 ... Bearing alloy processed part, 404 ... Sliding member (oil stop), 405 ... Oil (lubricating oil), 501 ... Oil supply port , 502 ... Bearing metal outer oil reservoir, 503 ... Bearing main body metal receiving part, 504 ... Oil tank, 505 ... Oil discharge port, 506 ... Oil level, 601 ... Chamfered part.

Claims (14)

A sliding bearing that rotatably supports the rotating shaft and causes the rotating shaft to slide on the bearing surface,
The sliding bearing is provided with a plurality of sliding members extending in a circumferential direction at a predetermined interval on the bearing surface in the insertion direction of the rotating shaft,
A sliding bearing, wherein an oil filler port is provided between each of the plurality of sliding members. The plain bearing according to claim 1,
A damming portion for restricting the flow of lubricating oil is provided in a region sandwiched between two sliding members adjacent to the oil supply port provided on the lowermost side in the gravity direction among the oil supply ports. A plain bearing. The plain bearing according to claim 1,
When the rotary shaft is inserted into the slide bearing, a gap between the bearing surface and the rotary shaft at both ends of the bearing surface is formed narrower than a gap between the bearing surface and the rotary shaft at the center of the bearing surface. A plain bearing characterized by being made. The sliding bearing according to claim 2,
The area surrounded by the two sliding members and the damming portion has a rectangular shape. The sliding bearing according to any one of claims 1 to 4,
A sliding bearing, wherein a chamfered portion is provided on two sliding members adjacent to the oil supply port provided on the lowermost side in the gravity direction among the oil supply ports. A sliding bearing according to any one of claims 1 to 5,
The sliding bearing is a hydrostatic bearing type sliding bearing in which a lubricating film is formed between the rotating shaft and the bearing surface by supplying lubricating oil from the oil supply port to the bearing surface. bearing. The sliding bearing according to any one of claims 1 to 6,
The plain bearing is composed of two semi-cylindrical bearing members that can be divided into upper and lower parts,
The sliding bearing and the oil filler opening are provided on a bearing surface of a lower bearing member of the two bearing members. An electric motor having a coil and a core mounted therein and rotating a rotating shaft by induced current,
The rotating shaft is rotatably supported by a slide bearing,
The sliding bearing is provided with a plurality of sliding members extending in a circumferential direction at a predetermined interval on the bearing surface in the insertion direction of the rotating shaft,
An electric motor provided with a slide bearing, wherein an oil supply port is provided between each of the plurality of sliding members. The electric motor according to claim 8,
A damming portion for restricting the flow of lubricating oil is provided in a region sandwiched between two sliding members adjacent to the oil supply port provided on the lowermost side in the gravity direction among the oil supply ports. An electric motor equipped with a sliding bearing. The electric motor according to claim 8,
When the rotary shaft is inserted into the slide bearing, a gap between the bearing surface and the rotary shaft at both ends of the bearing surface is formed narrower than a gap between the bearing surface and the rotary shaft at the center of the bearing surface. An electric motor having a plain bearing characterized by being made. The electric motor according to claim 9,
An electric motor provided with a slide bearing, wherein a region surrounded by the two sliding members and the damming portion is rectangular. The electric motor according to any one of claims 8 to 11,
A motor provided with a slide bearing, wherein chamfered portions are provided in two sliding members adjacent to the oil supply port provided on the lowermost side in the direction of gravity among the oil supply ports. The electric motor according to any one of claims 8 to 12,
The sliding bearing is a hydrostatic bearing type sliding bearing in which a lubricating film is formed between the rotating shaft and the bearing surface by supplying lubricating oil from the oil supply port to the bearing surface. An electric motor with a bearing. The electric motor according to any one of claims 8 to 13,
The plain bearing is composed of two semi-cylindrical bearing members that can be divided into upper and lower parts,
The sliding bearing motor according to claim 1, wherein the sliding member and the oil filler port are provided on a bearing surface of a lower bearing member of the two bearing members.

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