JP2018057219A - Bearing structure and vertical rotary electrical machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stabilize lubrication oil in an oil tank of a vertical rotary electrical machine to enhance a bearing function.SOLUTION: A bearing structure 100 rotatably supporting a rotor including a rotor shaft 11 extending in a vertical direction comprises: a thrust bearing 110, a journal bearing 120; and an oil tank 130. The thrust bearing 110 comprises: a plurality of thrust pads 112 which are made stationary and fixed in the oil tank 130 and annularly arranged at predetermined spaces in the circumferential direction; and a runner 111 which includes an overhang part 111m, a runner cylindrical part 111n, and a lower end part 111p arranged in the lower side of the runner cylindrical part 111n undersurface of which faces the top face of the thrust pad 112 formed flat. A stepped part inner diameter of which is upwardly decreased is formed at the inner surface of the runner 111 facing the outer surface of an oil cylinder 118 in which the inner diameter thereof is decreased as it becomes closer to the upper side of the stepped part.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a bearing structure and a vertical rotary electric machine having the same.

  In a vertical rotating electrical machine having a rotating shaft in a vertical direction, a rotating portion such as a rotor is rotatably supported by an upper bearing portion and a lower bearing portion. The upper bearing portion includes a thrust bearing that supports the weight of the rotating portion, and a journal bearing that is a slide bearing that supports a radial load. The lower bearing portion has a journal bearing.

  In the thrust bearing, a cylindrical runner extending in the main axis direction, that is, the vertical direction is attached to the shaft in order to support the rotating portion. The lower part of the runner is mounted on a stationary receiving member and is coupled to the upper side of the thrust bearing. Since the sliding portion of the thrust bearing generates a large amount of heat, it is usually immersed in an oil tank (Patent Document 1).

  FIG. 5 is a partial vertical sectional view showing an example of the configuration around the upper bearing portion of a conventional vertical rotating electrical machine. The upper bearing portion cover 125 and the oil cylinder 118 form an oil tank. That is, the upper bearing portion cover 125 has a cylindrical portion, an upper lid portion, and a bottom portion, and an opening through which the rotor shaft 11 of the rotor passes is formed in the bottom portion. The oil cylinder 118 rises in a cylindrical shape from the periphery of the opening at the bottom of the upper bearing portion cover 125. An annular oil tank is formed by the radially inner oil cylinder 118 and the cylinder part and bottom part of the radially outer upper bearing cover 125.

  A runner 51 is fixed to the rotor shaft 11 of the rotor. The runner 51 extends in a cylindrical shape vertically downward from an attachment portion to the rotor shaft 11, and a horizontal plane is formed at the bottom. A portion below the intermediate height of the runner 51 is immersed in the lubricating oil stored in the annular oil tank.

  The bottom of the runner 51 is mounted on a thrust pad 112 fixed in the oil tank.

  FIG. 6 is an elevational sectional view showing details of a portion B in FIG. A journal bearing oil supply hole 51a penetrating from the plurality of inner surfaces to the outer surface is formed at the same height in the cylindrical portion of the runner 51 so as to be spaced apart from each other in the circumferential direction. A journal bearing 120 that is stationary and fixed is provided outside the journal bearing oil supply hole 51a in the radial direction.

  A stepped portion 51 f is formed on the inner surface side of the cylindrical portion of the runner 51. The lower inner diameter of the cylindrical portion is wider than the upper inner diameter with the stepped portion 51f as a boundary. The lower inner diameter and the upper inner diameter of the cylindrical portion are constant with respect to the change in height. A first annular protrusion 51c is continuously formed in the circumferential direction above the stepped portion 51f. Further, the cylindrical portion of the runner 51 is higher than the lubricating oil surface, and penetrates from the plurality of inner surfaces to the outer surface below the first annular protrusions 51c at the same height and spaced from each other in the circumferential direction. A communicating hole 51b is formed.

JP-A-8-270891

  During operation of the rotating electrical machine, the cylindrical portion of the runner 51 rotates in the oil tank on the radially outer side of the oil cylinder 118. Since the lower part of the runner 51 is immersed in the lubricating oil in the oil tank, the runner 51 rotates while stirring the lubricating oil.

  7A and 7B are first explanatory views of a problem of a conventional vertical rotating electrical machine bearing, in which FIG. 7A shows a splashing phenomenon of the lubricating oil, and FIG. 7B shows a rising phenomenon of the lubricating oil. FIG. 7 shows a case where the distance between the outer surface of the oil cylinder 118 and the inner surface of the cylindrical portion of the runner 51 is relatively narrow.

  In such a case, the lubricating oil in the annular space between the outer surface of the oil cylinder 118 and the inner surface of the cylindrical portion of the runner 51 is greatly affected by the rotating runner 51. That is, a splash phenomenon occurs in which the liquid level largely fluctuates up and down, and when the liquid level rises, there is a possibility that the lubricating oil flows over the oil cylinder 118 and flows into the rotor shaft 11 side. It should be noted that the degree of rising due to the distribution of the circumferential speed of the lubricating oil in the radial direction caused by the rotation of the lubricating oil is small.

  FIGS. 8A and 8B are second explanatory views of the problems of the conventional vertical rotary electric machine bearing, in which FIG. 8A shows the splashing phenomenon of the lubricating oil, and FIG. 8B shows the rising phenomenon of the lubricating oil. FIG. 8 shows a case where the distance between the outer surface of the oil cylinder 118 and the inner surface of the cylindrical portion of the runner 51 is relatively wide.

  In such a case, the degree of the splash phenomenon is small, and there is no concern that the lubricating oil flows over the oil cylinder 118 and flows into the rotor shaft 11 side. However, as the inner diameter of the cylindrical portion of the runner 51 increases, the peripheral speed of the lubricating oil generated by the accompanying rotation of the lubricating oil increases, and the degree of the rising of the lubricating oil to the inner surface of the cylindrical portion of the runner 51 increases. For this reason, the thickness of the lubricating oil on the inner surface side of the cylindrical portion of the runner 51 of the lubricating oil in the journal bearing oil supply hole 51a is reduced, and gas is entrained. For this reason, sufficient lubricating oil is not supplied between the inner surface of the journal bearing 120 and the outer surface of the runner 51, and the function of the journal bearing 120 is affected.

  That is, if the gap between the outer surface of the oil cylinder 118 and the inner surface of the cylindrical portion of the runner 51 is increased in order to eliminate the splash phenomenon, the lubricating oil rises to the inner surface of the cylindrical portion of the runner 51 to the journal bearing oil supply hole 51a. The possibility of gas entrainment increases.

  Accordingly, an object of the present invention is to enhance the bearing function by making the lubricating oil in the oil tank of the vertical rotating electrical machine stable.

  In order to achieve the above-mentioned object, the present invention rotatably supports a rotor having a rotor shaft extending in the vertical direction, and is for thrust bearing, journal bearing, lubrication and cooling of the thrust bearing and the journal bearing. A bearing structure for a vertical rotating electrical machine including an annular stationary oil tank that stores a lubricating oil of the rotor, wherein the oil tank has at least an outer cylinder part and a bottom part, and the rotor shaft is provided at the bottom part. An upper bearing cover in which an opening is formed for penetrating through, and a cylindrical oil that is fixed to the bottom near the edge of the opening of the upper bearing cover and that extends vertically upward, with a lower end fixed The thrust bearing is fixed stationary in the oil tank, the upper surface is formed in a flat shape, and is arranged annularly with a circumferential interval between each other on the radially outer side of the rotor shaft. A plurality of thrust pads, a projecting portion fixed to the rotor shaft and projecting radially outward from the fixed portion to the rotor shaft, a runner cylindrical portion extending downward from the projecting portion, and a lower portion of the runner cylindrical portion A runner having a lower surface formed on the side and having a lower surface facing the upper surface of the thrust pad, and the inner diameter of the runner facing the outer surface of the oil cylinder is reduced upward. A stepped portion is formed, and the inner diameter of the inner surface of the runner becomes smaller as it goes above the stepped portion.

  In addition, the present invention provides a rotor having a rotor shaft extending in the vertical direction, a rotor having a rotor core provided on the radially outer side of the rotor shaft, and a cylinder arranged stationary on the radially outer side of the rotor. Stator, a thrust bearing that rotatably supports the rotor, a journal bearing, and an annular stationary and fixed oil tank that contains lubricating oil for lubrication and cooling of the thrust bearing and the journal bearing , And a lower bearing portion that supports a radial load at the lower portion of the rotor, wherein the oil tank has at least an outer cylinder portion and a bottom portion. An upper bearing cover in which an opening for allowing the rotor shaft to pass through is formed at the bottom, and a lower end is fixed to the bottom near the edge of the opening of the upper bearing cover and vertically upward The thrust bearing is fixedly supported in the oil tank and has an upper surface formed in a flat shape, and is arranged annularly with a circumferential interval on the radially outer side of the rotor shaft. A plurality of thrust pads, a projecting portion fixed to the rotor shaft and projecting radially outward from a fixed portion to the rotor shaft, a runner cylindrical portion extending downward from the projecting portion, and a runner cylindrical portion A runner having a lower surface formed on a lower surface and having a lower surface facing the upper surface of the thrust pad, and the inner surface of the runner facing the outer surface of the oil cylinder has an inner diameter upward. A stepped portion to be reduced is formed, and the inner diameter of the inner surface of the runner becomes smaller as it goes above the stepped portion.

  According to the present invention, the lubricating oil in the oil tank of the vertical rotating electrical machine can be made stable to enhance the bearing function.

It is an elevation sectional view showing the composition of the vertical rotary electric machine concerning an embodiment. It is a fragmentary sectional view which shows the structure of the bearing structure of the vertical rotary electric machine which concerns on embodiment. FIG. 3 is a horizontal sectional view taken along line III-III in FIG. 2. FIG. 3 is an elevational sectional view showing details of a portion A in FIG. 2. It is a fragmentary sectional view which shows the structural example around the upper bearing part of the conventional vertical rotary electric machine. FIG. 6 is an elevational sectional view showing details of a portion B in FIG. 5. It is the 1st explanatory view of the subject of the bearing of the conventional vertical rotating electrical machine, (a) shows the splash phenomenon of lubricating oil, and (b) shows the rising phenomenon of lubricating oil. It is the 2nd explanatory view of the subject of the bearing of the conventional vertical rotary electric machine, (a) shows the splash phenomenon of lubricating oil, and (b) shows the rising phenomenon of lubricating oil.

  Hereinafter, a bearing structure and a vertical rotating electrical machine according to an embodiment of the present invention will be described with reference to the drawings. Here, the same or similar parts are denoted by common reference numerals, and redundant description is omitted.

  FIG. 1 is a vertical sectional view showing a configuration of a vertical rotating electrical machine 200 according to the embodiment. The vertical rotary electric machine 200 includes a rotor 10, a stator 20, a bearing structure 100, a lower bearing portion 40, and a frame 150.

  The rotor 10 includes a rotor shaft 11 extending in the vertical direction, and a rotor core 12 that is provided radially outside the rotor shaft 11 and rotates integrally with the rotor shaft 11. The stator 20 includes a stator core 21 provided in the radial direction of the rotor core 12 and a stator coil 22 installed in a slot (not shown) formed in the stator core 21.

  The frame 150 houses a part of the rotor shaft 11, the rotor core 12, and the stator 20. The rotor 10 is rotatably supported by a bearing structure 100 provided at the upper part of the frame 150 and a lower bearing part 40 provided at the lower part of the frame 150. The lower bearing portion 40 includes an oil tank 41 provided in the lower part of the frame 150 and a journal bearing 42 provided in the oil tank 41.

  The bearing structure 100 includes a thrust bearing 110 that supports the weight of the rotor, a journal bearing 120, and an oil tank 130 that stores lubricating oil for lubricating and cooling the thrust bearing 110 and the journal bearing 120.

  The oil tank 130 has an upper bearing portion cover 125 and an oil cylinder 118. The upper bearing portion cover 125 has an outer cylinder portion 125a, a bottom portion 125b, and an upper lid portion 125c. An opening for allowing the rotor shaft 11 to pass therethrough is formed in the bottom 125b. The bottom portion 125 b is fixed to a horizontal end plate 150 a at the upper end of the frame 150. The outer cylinder part 125a has a cylindrical shape whose upper and lower sides are opened, and the lower end is attached in close contact with the bottom part 125b. The upper lid portion 125c is attached horizontally so as to close the opening at the upper end of the outer cylinder portion 125a.

  The oil cylinder 118 is cylindrical and the upper and lower parts are open. The oil cylinder 118 is provided on the radially outer side of the rotor shaft 11 with a gap from the rotor shaft 11. The lower end of the oil cylinder 118 is attached to the bottom 125 b near the edge of the opening formed in the bottom 125 b of the upper bearing cover 125. As a result, the outer cylinder part 125a, the oil cylinder 118, and the bottom part 125b of the upper bearing part cover 125 constitute an oil tank 130 that is an annular container for storing lubricating oil.

  Lubricating oil is stored in the oil tank 130. The thrust bearing 110 and the journal bearing 120 are each immersed in the oil tank 130 except for a part.

  FIG. 2 is a partial vertical sectional view showing the configuration of the bearing structure 100 of the vertical rotating electrical machine 200 according to the embodiment. 3 is a horizontal sectional view taken along line III-III in FIG.

  The thrust bearing 110 supports the weight of the rotor 10 (FIG. 1). The thrust bearing 110 includes a runner 111, a thrust pad 112, a pad support 113, and a base plate 114.

  The runner 111 is attached to the outer surface of the rotor shaft 11. The runner 111 has a projecting portion 111m, a runner cylindrical portion 111n, and a lower end portion 111p. The overhanging portion 111m is a portion fixed to the rotor shaft 11, and is higher than the level of the upper end of the oil cylinder 118 from the fixing portion to the rotor shaft 11 from the outside in the radial direction of the oil cylinder 118 when viewed in plan. Overhang in the radial direction.

  The runner cylindrical portion 111n is a portion that continuously extends below the overhanging portion 111m and extends downward in a cylindrical shape, and is provided outside the oil cylinder 118 in the radial direction. The lower end portion 111p is a portion connected to the lower side of the runner cylindrical portion 111n, and the lower surface is formed in a planar shape. The lower end 111p faces the upper surface of the thrust pad 112 of the thrust bearing 110 and is mounted on the upper surface of the thrust pad 112.

  The base plate 114 has a substantially rectangular parallelepiped shape, and a plurality of base plates 114 are provided. The base plates 114 are annularly arranged at intervals in the circumferential direction, and are fixed to the bottom portion 125 b of the upper bearing portion cover 125. On the base plate 114, a disc-shaped pad support portion 113 having an opening at the center is attached. The base plate 114 and the pad support portion 113 are not limited to such shapes. For example, the base plate 114 and the pad support portion 113 may be combined into one annular support base, and through holes that are directed in the radial center may be arranged in the circumferential direction.

  On the pad support portion 113, a plurality of thrust pads 112 are mounted annularly at intervals in the circumferential direction. Each thrust pad 112 has a flat upper surface and is constrained so as not to move in either the radial direction or the circumferential direction. A protrusion is formed substantially at the center of the lower surface of each thrust pad 112. When the lower end 111p of the runner 111 moves in the circumferential direction on the thrust pad 112, the thrust pad 112 is formed to be inclined with respect to the horizontal direction toward the circumferential direction, and the lower surface of the lower end 111p of the runner 111 Then, the lubricating oil is guided to the gap between the thrust pad 112 and the upper surface of the thrust pad 112.

  As a result, when the runner 111 is mounted on the thrust pad 112 and rotates with the rotation of the rotor shaft 11, the upper surface of the thrust pad 112 is not in close contact with the lower surface of the lower end portion 111 p of the runner 111 and It becomes inclined. Therefore, the lubricating oil is guided to the space between the upper surface of the thrust pad 112 and the lower surface of the lower end portion 111p of the runner 111.

  Between the upper surface of the thrust pad 112 and the lower surface of the lower end portion 111p of the runner 111, the lubricating oil flows from the radially inner side to the radially outer side due to the centrifugal force generated by the rotation of the runner 111. In the space formed in the radial direction between the base plates 114 adjacent to each other of the thrust bearing 110, the lubricating oil flows from the radially outer side to the radially inner side, and the lubricating oil flowing out from the thrust pad 112 is replenished. Is done.

  A plurality of journal bearing oil supply holes 111a are formed at a position lower than the lubricating oil level of the runner cylindrical portion 111n at intervals in the circumferential direction. An annular journal bearing 120 is provided at the height of the journal bearing oil supply hole 111a with a small gap formed on the radially outer side of the runner cylindrical portion 111n.

  The lubricating oil flows out from the inner side of the runner cylindrical portion 111n to the outer side in the radial direction through the journal bearing oil supply hole 111a by the centrifugal force of the flow along the rotation of the runner 111. Lubricating oil that has flowed out from the inner surface of the runner cylindrical portion 111n to the outer surface of the runner cylindrical portion 111n and the inner surface of the journal bearing 121 flows upward. At this time, due to the static pressure generated between the outer side of the journal bearing oil supply hole 111a and the inner side in the radial direction of the support wheel 121, a force acting in the direction of the rotation axis is generated in each part in the circumferential direction. A restraining force to the radial displacement is generated.

  A plurality of communication holes 111b are formed at a position higher than the oil level of the lubricating oil in the runner cylindrical portion 111n at intervals in the circumferential direction. The communication hole 111 b is for discharging the gas that has been involved in the lubricating oil in the oil tank 130 and has moved to the inside of the runner 111 from the runner 111.

  FIG. 4 is an elevational sectional view showing details of a portion A in FIG. A stepped portion 111f is formed on the inner surface side of the runner cylindrical portion 111n. With the stepped portion 111f as a boundary, the lower inner diameter of the runner cylindrical portion 111n is wider than the upper inner diameter.

  A portion of the inner surface of the runner cylindrical portion 111n above the stepped portion 111f has an inner diameter that decreases upward, forming a so-called tapered portion 111w.

  A first annular protrusion 111c is formed continuously in the circumferential direction on the inner surface of the runner cylindrical portion 111n and above the communication hole 111b. A second annular projection 111d is formed on the inner surface of the runner cylindrical portion 111n below the communication hole 111b. A gap is formed between the inner surface of the first annular protrusion 111c and the outer surface of the oil cylinder 118 so that the first annular protrusion 111c and the oil cylinder 118 do not contact while the runner 111 is rotating. Similarly, a gap is formed between the inner surface of the second annular protrusion 111d and the outer surface of the oil cylinder 118 so that the second annular protrusion 111d and the oil cylinder 118 do not contact while the runner 111 is rotating.

  In the present embodiment configured as described above, first, the stepped portion 111f becomes a resistance against the fluctuation of the oil level. Further, the lubricating oil that further rises in the annular space between the inner surface of the runner cylindrical portion 111n and the oil cylinder 118 becomes a resistance that becomes narrower as it rises in the annular space, and the occurrence of the splash phenomenon is hindered.

  Further, the second annular protrusion 111d prevents the lubricating oil from flowing out of the cylindrical portion of the runner 111 from the communication hole 111b.

  As described above, in the vertical rotary electric machine 200, the lubricating oil in the annular space between the outer surface of the oil cylinder 118 and the inner surface of the cylindrical portion of the runner 111 can be stabilized to enhance the bearing function. it can.

[Other Embodiments]
As mentioned above, although embodiment of this invention was described, embodiment is shown as an example and is not intending limiting the range of invention. The embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. The embodiments and the modifications thereof are included in the scope of the invention and the scope of the invention, and are also included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 10 ... Rotor, 11 ... Rotor shaft, 12 ... Rotor iron core, 20 ... Stator, 21 ... Stator iron core, 22 ... Stator coil, 40 ... Lower bearing part, 41 ... Oil tank, 42 ... Journal bearing, 51 ... Runner, 51a ... journal bearing oil supply hole, 51b ... communication hole, 51c ... first annular protrusion, 51f ... stepped portion, 100 ... bearing structure, 110 ... thrust bearing, 111 ... runner, 111a ... journal bearing oil supply hole, 111b ... Communication hole, 111c ... first annular protrusion, 111d ... second annular protrusion, 111f ... stepped part, 111m ... projecting part, 111n ... runner cylindrical part, 111p ... lower end part, 111w ... tapered part, 112 ... thrust pad, DESCRIPTION OF SYMBOLS 113 ... Pad support part, 114 ... Base plate, 118 ... Oil cylinder, 120 ... Journal bearing, 121 ... Support wheel, 125 ... Upper bearing part cover, 125a The outer tube portion, 125b ... bottom, 125c ... upper cover, 130 ... oil tank, 150 ... frame, 150a ... end plate, 200 ... Vertical rotating electrical machine

Claims (4)

A rotor having a rotor shaft extending in the vertical direction is rotatably supported, and is fixed in an annular shape to hold a thrust bearing, a journal bearing, and a lubricating oil for lubricating and cooling the thrust bearing and the journal bearing. A vertical rotating electrical machine bearing structure comprising an oil tank,
The oil tank is
An upper bearing part cover having at least an outer cylinder part and a bottom part, and an opening part through which the rotor shaft passes is formed in the bottom part;
A cylindrical oil cylinder having a lower end fixed to the bottom near the edge of the opening of the upper bearing cover and extending vertically upward;
Have
The thrust bearing is
A plurality of thrust pads that are fixedly fixed in the oil tank and have an upper surface formed in a planar shape, and are arranged annularly with a circumferential interval from each other radially outside the rotor shaft;
A projecting portion fixed to the rotor shaft and projecting radially outward from a fixed portion to the rotor shaft; a runner cylindrical portion extending downward from the projecting portion; and a lower surface provided on a lower side of the runner cylindrical portion. A runner having a lower end facing the upper surface of the thrust pad,
Have
A stepped portion whose inner diameter is reduced upward is formed on the inner surface of the runner facing the outer surface of the oil cylinder, and the inner diameter of the inner surface of the runner becomes smaller as it is above the stepped portion.
A bearing structure characterized by that.   2. The bearing structure according to claim 1, wherein the diameter becomes smaller toward the upper side of the stepped portion due to formation of a tapered portion. A communication hole for gas communication penetrating in the radial direction is formed above the stepped portion of the runner,
3. The bearing structure according to claim 1, wherein an inward projection is formed on the inner surface of the runner below the communication hole. A rotor having a rotor shaft extending in the vertical direction and a rotor iron core provided radially outside the rotor shaft;
A cylindrical stator that is arranged on the radially outer side of the rotor and fixed stationary;
A bearing that rotatably supports the rotor, and includes a thrust bearing, a journal bearing, and an annular stationary and fixed oil tank that contains lubricating oil for lubricating and cooling the thrust bearing and the journal bearing. A structure,
A lower bearing portion for supporting a radial load at a lower portion of the rotor;
A vertical rotary electric machine comprising:
The oil tank is
An upper bearing part cover having at least an outer cylinder part and a bottom part, and an opening part through which the rotor shaft passes is formed in the bottom part;
A cylindrical oil cylinder having a lower end fixed to the bottom near the edge of the opening of the upper bearing cover and extending vertically upward;
Have
The thrust bearing is
A plurality of thrust pads fixedly supported in the oil tank and having an upper surface formed in a planar shape, and arranged in an annular manner at intervals in the circumferential direction on the radially outer side of the rotor shaft;
A projecting portion fixed to the rotor shaft and projecting radially outward from a fixed portion to the rotor shaft; a runner cylindrical portion extending downward from the projecting portion; and a lower surface provided on a lower side of the runner cylindrical portion. A runner having a lower end facing the upper surface of the thrust pad,
Have
A stepped portion whose inner diameter is reduced upward is formed on the inner surface of the runner facing the outer surface of the oil cylinder, and the inner diameter of the inner surface of the runner becomes smaller as it is above the stepped portion.
A vertical rotary electric machine characterized by that.

Images