JP6116278B2 - Bearing device and rotating machine equipped with the bearing device - Google Patents

Description

  The present invention relates to a bearing pad that rotatably supports a rotating shaft (rotor) of a large-sized rotating machine such as a steam turbine, a gas turbine, a compressor, and a generator, a bearing device including the same, and a rotating machine including the bearing device About.

  An example of a bearing device used in a conventional rotating machine is shown in FIGS. The bearing device 100 is called a journal bearing or a tilting pad bearing, and a plurality (four in this example) of bearing pads are arranged at a predetermined interval along the circumferential direction of the axis O of the rotating shaft 101. 102. These bearing pads 102 are accommodated in the housing 103 and support the rotating shaft 101 so as to be rotatable around the axis O. In journal bearings for large rotating machines, lubrication is generally performed by oil bath lubrication in order to enable safe operation of the machine, and there is no lubricating oil between the rotating shaft 101 and the bearing pad 102. An oil film is formed.

  The bearing pad 102 is supported by a pivot 104, and the pivot 104 is known as a point support type for the purpose of preventing the rotation shaft 101 from coming into contact with each other. In the case of the point support type, the bearing pads 102 are supported so as to be swingable in an arbitrary direction around the support point of the pivot 104 having a hemispherical shape, for example, with respect to the corresponding support ring 3. . The bearing pad 102 swings according to the rotation of the rotating shaft 101 and tilts. The inner peripheral surface (sliding surface) 102a of the bearing pad 102 and the outer peripheral surface (sliding surface) of the rotating shaft 101 are caused by the wedge action of the oil film. Oil film pressure is generated with respect to 101a. This oil film pressure generated on the bearing pad 102 located on the lower half side of the bearing device 100 is configured to support the excessive weight (load) of the rotating shaft 101.

  The lubricating oil supplied from the oil supply hole 106 opened in the housing 103 passes through the inside of the housing 103 from the nozzle 107 located on the rear side in the rotation direction of the bearing pad 102 toward the outer peripheral surface 101 a of the rotary shaft 101. Erupted. Thus, lubrication is performed by forming an oil film between the outer peripheral surface 101a of the rotating shaft 101 and the inner peripheral surface 102a of the bearing pad 102 to reduce friction.

  As in this bearing device 100, a bearing of a type in which the bearing is not filled with lubricating oil and the lubricating oil is supplied only to the sliding portion between the rotating shaft 101 and the bearing pad 102 is generally a direct lubricated bearing. being called. In this direct lubrication type bearing, since the lubricating oil is not filled in the bearing, when the amount of oil supplied from the nozzle 107 decreases due to a decrease in pump oil supply pressure, the amount of oil supplied from the nozzle 107 decreases.

  In such a case, the lubricating oil does not spread over the entire sliding surface between the rotating shaft 101 and the bearing pad 102, and the vicinity of the rear edge of the bearing pad 102 (the most downstream end in the lubricating oil flow direction on the inner peripheral surface 102 a of the bearing pad 102). A situation occurs where only the portion 102b) is lubricated. As a result, local shear heat generation of the lubricating oil occurs particularly in the vicinity of the rear edge of the bearing pad 102, and the temperature rise of the oil film and the bearing pad 102 is locally increased. Therefore, thermal stress and thermal deformation occur in the bearing pad 102, and the load capacity of the bearing device 100 (the weight of the rotating shaft that the bearing can support) is reduced, or problems such as seizure and deterioration of the lubricating oil occur. There was a problem.

  Here, FIG. 15 shows the analysis result of the temperature distribution of the oil film on the inner peripheral surface 102 a of the bearing pad 102. From this, it can be seen that a region H having the highest temperature is generated near the rear edge of the bearing pad 102 (near the most downstream end portion 102b in the flow direction of the lubricating oil on the inner peripheral surface 102a). Further, in the vicinity of the most downstream end portion 102b in the lubricating oil flow direction on the inner peripheral surface 102a, the region H is wider at the center portion than at both end portions in the width direction of the bearing pad 102 (in the direction of the axis O of the rotating shaft 101). From the distribution, it can be seen that the temperature is higher at the center. Further, the isothermal lines are substantially parallel to each other in the axial direction on the downstream side of the bearing pad 102 in the flow direction.

  Further, as an important function of the lubricating oil, in addition to the lubricating function, there is also a cooling function by absorbing and removing the heat generated on the inner peripheral surface 102a as described above. However, the lubricating oil after acting on the inner peripheral surface 102a of one bearing pad 102 flows into the inner peripheral surface 102a of the bearing pad 102 adjacent to the downstream side in the flow direction of the lubricating oil as so-called carry-over oil. End up. Further, since the lubricating oil flows in a direction orthogonal to the pressure contour line, it flows in a direction orthogonal to the radial direction, that is, in the circumferential direction, and as the carry-over oil, the inner peripheral surface of the bearing pad 102 adjacent to the downstream in the flow direction of the lubricating oil It flows into 102a. For this reason, when the lubricating oil that has acted at one bearing pad 102 and has reached a high temperature flows into the inner peripheral surface 102a of the adjacent bearing pad 102 as carry-over oil, the cooling action there is reduced, and as a result There has been a problem in that the required amount of lubricating oil is increased.

  In other words, how to prevent the carry-over oil from flowing directly affects the bearing efficiency, which leads to a reduction in the amount of lubricating oil. This reduction in the amount of lubricating oil greatly affects the cost reduction and downsizing of the journal bearing system because the lubricating oil supply device and the auxiliary equipment such as the oil storage tank occupy a large specific gravity in the journal bearing system. . In addition, with regard to the lubricating oil, there is an agitation loss accompanying the agitation of the lubricating oil due to the rotation of the rotating shaft 101, but this agitation loss can also be reduced by reducing the amount of the lubricating oil, resulting in a reduction in bearing loss.

  As an invention for preventing such carry-over oil, for example, the following Patent Document 1 has been proposed.

  Further, the bearing device described in Patent Document 1 is elongated in the axial direction on the sliding end (inner peripheral surface) of the pad at the rear end portion on the downstream side with respect to the moving direction of the lubricating oil accompanying the rotation of the rotating shaft, An oil guide groove having at least one end opened toward the side plate is provided. Also, a clogging fence that opens in the side plate at a position corresponding to the open end of the oil guide groove, and further projects inward in a state perpendicular to the flow of lubricating oil flowing in the gap between the pad and the side plate. Is provided on the side plate so as to be close to the oil discharge port.

JP 2003-176818 A

  In the bearing device described in Patent Document 1, when the speed of the rotating shaft is high, the lubricating oil between the pad and the rotating shaft is reliably guided to the oil guiding groove, and the efficiency from the oil discharge port is increased. May not be discharged. In this case, there is a problem that the lubricating oil flows into the adjacent pad on the downstream side in the flow direction of the lubricating oil as carry-over oil, and the adjacent pad cannot be efficiently cooled.

  The present invention has been made to solve the above-described problem, and is a bearing pad capable of efficiently discharging lubricating oil having a high temperature from between the rotating shaft and the support surface of the rotating shaft of the bearing pad. Provided are a bearing device including the same and a rotating machine including the bearing device.

In order to achieve the above object, the present invention employs the following means.
That is, the bearing device according to the present invention includes a housing and a plurality of circumferentially arranged rotating shafts supported in the housing so as to be swingable and rotating about an axis, and a gap between the rotating shaft and the outer peripheral surface of the rotating shaft. A pad body that supports the rotary shaft from the outer peripheral side by a pad support surface, and both edge portions on both sides in the axial direction of the pad support surface on the front side in the rotation direction of the rotary shaft are provided. , with progressively closer together toward the front Symbol rotation direction front side, the bearing pads are formed so as to be connected to each other in the rotational direction forward from between the bearing pads adjacent to each other in the gap lubrication and a lubricating oil supply section for supplying oil, and the shape of the pad mounting surface which is a rear surface of the pad support surface, the shape of the pad support surfaces are different from each other, the pad support Characterized in that it is connected between the pad mounting surface and each other, a connecting wall portion which is formed so as to gradually toward the rotational direction front side toward the radially outer side.

In such a bearing pad, at least one of both edge portions on both sides in the axial direction on the front side in the rotation direction of the pad support surface is directed toward the front side in the rotation direction of the rotation shaft, and therefore close to the other of both edge portions on both sides in the axial direction. It is formed as follows. As a result, the pressure contour line on the pad support surface is a line that is close to the other side from one of both edges corresponding to the shape of the end portion on the front side in the rotational direction of the pad support surface. Therefore, since the lubricating oil on at least one side of both edges flows in the direction perpendicular to the pressure contour line as described above, the lubricating oil is directed outward in the width direction of the support surface (axial direction of the rotating shaft) and forward in the rotational direction of the rotating shaft. Flowing. Therefore, the lubricating oil that has reached a high temperature can be discharged from between the rotation shaft front side of the rotation shaft and the rotation shaft of the bearing pad rotation shaft support surface (pad support surface).
In such a bearing pad, the lubricating oil flows on both sides of the both edge portions of the pad support surface toward the outside in the width direction of the support surface (axial direction of the rotation shaft) and toward the front side in the rotation direction of the rotation shaft. Accordingly, the lubricating oil having a high temperature can be discharged from both edges on the support surface (pad support surface) of the rotation axis of the bearing pad from between both edges on the front side in the rotation direction of the rotation shaft and the rotation shaft. .
In such a bearing device, the lubricating oil supplied from the lubricating oil supply section flows between the pad support surface and the outer peripheral surface of the rotating shaft, and at least one side of both edges, the width direction of the support surface ( It flows toward the outside in the axial direction of the rotating shaft) and forward in the rotating direction of the rotating shaft. Therefore, the lubricating oil having a high temperature can be discharged from between the rotating shaft front side of the rotating shaft on the supporting surface (pad supporting surface) of the bearing pad and the rotating shaft. Therefore, the lubricating oil that has flowed through the pad support surface of one bearing pad does not flow into the other bearing pads on the front side in the rotational direction.
Also, the shape of the pad mounting surface opposite to the pad supporting surface and the shape of the pad supporting surface are different from each other, and the pad supporting surface and the pad mounting surface gradually move forward in the rotational direction toward the radially outer side. Since the area of the pad mounting surface is larger than the area of the pad support surface by being connected by the connecting wall portion formed to face the pad body, the pad main body can be securely attached to another support member and the pad The support surface can reliably discharge the lubricating oil.

  Moreover, the bearing pad which concerns on this invention may be formed in the circular arc shape which the edge part of the said rotation direction front side of the said pad support surface swells toward the said rotation direction front side.

  In such a bearing pad, the lubricating oil flows over a wide range on the front side in the rotation direction of the pad support surface, outward in the width direction of the support surface (axial direction of the rotation shaft) and toward the front side in the rotation direction of the rotation shaft. Therefore, it is possible to reliably discharge the lubricating oil that has reached a high temperature from between the rotation shaft front side of the rotation shaft and the rotation shaft of the bearing pad rotation shaft support surface (pad support surface).

  In the bearing pad according to the present invention, the shape of the pad mounting surface opposite to the pad support surface and the shape of the pad support surface may be the same.

  In such a bearing pad, since the shape of the pad mounting surface is the same as the shape of the pad support surface, the lubricating oil having a high temperature in the radial direction of the bearing pad can be discharged.

  A rotating machine according to the present invention includes the rotating shaft and the bearing device described above that rotatably supports the rotating shaft.

  In such a rotating machine, the lubricating oil that has flowed on the pad support surface of one bearing pad does not flow into the other bearing pads on the front side in the rotational direction.

  According to the bearing pad, the bearing device including the bearing pad, and the rotary machine including the bearing device according to the present invention, the lubricating oil on at least one side of both edge portions flows in the direction orthogonal to the pressure contour as described above. Then, it flows toward the outer side in the width direction of the support surface (the axial direction of the rotating shaft) and toward the front side in the rotating direction of the rotating shaft. Therefore, the lubricating oil that has reached a high temperature can be discharged on the front side in the rotation direction of the rotary shaft on the support surface (pad support surface) of the rotary shaft of the bearing pad. Accordingly, the lubricating oil having a high temperature can be efficiently discharged from between the rotating shaft and the support surface (pad support surface) of the rotating shaft of the bearing pad.

1 is a schematic cross-sectional view showing a steam turbine according to a first embodiment of the present invention. It is sectional drawing which shows the principal part of an example of the bearing apparatus using the bearing pad which concerns on 1st embodiment of this invention, Comprising: It is a fragmentary sectional view at the time of seeing in the cross section perpendicular | vertical with respect to the axis line of a rotating shaft. . It is the figure which looked at the pad support surface of the pad main body which concerns on 1st embodiment of this invention from radial inside (direction of arrow B in FIG. 2). It is the schematic perspective view which looked at the pad main body which concerns on 1st embodiment of this invention from radial inside. It is the figure which looked at the pad main body which concerns on 1st embodiment of this invention from the radial inside, (b) the figure seen from the axial direction, (c) The schematic perspective view seen from the radial inside. It is the figure which looked at the pad support surface of the pad main body which concerns on the modification 1 of 1st embodiment of this invention from radial inside. It is the figure which looked at the pad support surface of the pad main body which concerns on the modification 2 of 1st embodiment of this invention from radial inside. It is the figure which looked at the pad support surface of the pad main body which concerns on the modification 3 of 1st embodiment of this invention from radial inside. It is the figure which looked at the pad support surface of the pad main body which concerns on the modification 4 of 1st embodiment of this invention from radial direction inner side. It is the figure which looked at the pad main body which concerns on 2nd embodiment of this invention from the radial inside, (b) the figure seen from the axial direction, (c) The schematic perspective view seen from the radial inside. The pad main body which concerns on the modification 1 of 2nd embodiment of this invention (a) The figure seen from the radial inside, (b) The figure seen from the axial direction, (c) The schematic perspective view seen from the radial inside. is there. The pad main body which concerns on the modification 2 of 2nd embodiment of this invention (a) The figure seen from the radial inside, (b) The figure seen from the axial direction, (c) The schematic perspective view seen from the radial inside. is there. It is sectional drawing of the bearing apparatus using the conventional bearing pad. It is sectional drawing which shows the AA cross section in FIG. It is a perspective view which shows the analysis result of the temperature distribution of the oil film in the pad surface of the conventional bearing pad.

  Hereinafter, embodiments and modifications of a bearing pad according to the present invention, a bearing device including the same, and a rotary machine including the bearing device will be described in detail with reference to the drawings. In each embodiment and each modified example, description will be made centering on differences from the conventional bearing device described with reference to FIG. 13 to FIG.

(First embodiment)
First, a steam turbine 20 as an example of a rotating machine according to a first embodiment of the present invention will be described with reference to FIG. Here, the steam turbine is an external combustion engine that extracts steam energy as rotational power, and is used by being connected to a generator or the like in a power plant.

  As shown in FIG. 1, the steam turbine 20 includes a casing 30, a regulating valve 40 that adjusts the amount and pressure of steam S flowing into the casing 30, and a power generator (not shown) that is rotatably provided inside the casing 30. A shaft body 50 that transmits power (rotational energy) to a machine such as a machine, a stationary blade 60 held in the casing 30, a moving blade 70 provided on the shaft body 50, and the shaft body 50 and the moving blade 70 are aligned with each other. The main part is a bearing portion 80 that is rotatably supported around O.

  Casing 30 has an internal space hermetically sealed and a flow path for steam S. A ring-shaped partition plate outer ring (stator) 31 through which the shaft body 50 is inserted is firmly fixed to the inner wall surface of the casing 30.

  A plurality of regulating valves 40 are attached to the inside of the casing 30, and each includes a regulating valve chamber 41 into which steam S flows from a boiler (not shown), a valve body 42, and a valve seat 43. When the valve is separated from the valve seat 43, the steam flow path is opened, and the steam S flows into the internal space of the casing 30 through the steam chamber 44.

  The shaft body 50 includes a rotating shaft 10 that rotates around the axis, and a plurality of disks 11 that extend in the radial direction of the axis O from the outer peripheral surface 10a of the rotating shaft 10 (see FIG. 2).

  The bearing portion 80 includes a journal bearing (bearing device) 1 and a thrust bearing 81, and supports the shaft body 50 in a freely rotatable manner.

A large number of the stationary blades 60 are arranged radially so as to surround the shaft body 50 to form an annular stationary blade group, and are respectively held by the partition plate outer ring 31 described above. The inner sides in the radial direction of these stationary blades 60 are connected by a ring-shaped hub shroud 61 through which the shaft body 50 is inserted, and the tip ends thereof are disposed with a gap in the radial direction with respect to the shaft body 50. .
The group of annular stator blades composed of the plurality of stator blades 60 is formed at intervals in the axial direction, converts the pressure energy of the steam S into velocity energy, and moves to the rotor blade 70 adjacent to the downstream side. To guide you.

The rotor blade 70 is firmly attached to the outer periphery of the disk 11 included in the shaft body 50. A large number of the moving blades 70 are arranged radially on the downstream side of each annular stationary blade group to constitute the annular moving blade group.
These annular stator blade groups and annular rotor blade groups are grouped into one stage. That is, the steam turbine 20 is configured in six stages.

  Next, the bearing device 1 applied to the steam turbine 20 according to the present embodiment will be described with reference to FIGS.

  In the bearing device 1 of the present embodiment, as shown in FIG. 2, a plurality of (this embodiment) divided in the circumferential direction of the axis O of the rotary shaft 10 in a housing 2 in which a cross section orthogonal to the axis O is formed in an annular shape. Four support rings 3 are fixed in the form. Each support ring 3 has an arcuate cross section perpendicular to the axis O and a curved plate shape wide in the direction of the axis O. A gap C is provided in the radial direction of the axis O between the inner peripheral surface 2 b of the housing 2 and the outer peripheral surface 3 a of the support ring 3. The housing 2 has at least one oil supply hole (not shown) for supplying lubricating oil (see the oil supply hole 106 in FIG. 13), which penetrates from the outer peripheral surface 2a to the inner peripheral surface 2b of the housing 2. Not connected to the lubricating oil supply source and lubricating oil supply pump.

  A plurality (four in this embodiment) of oil supply nozzles (lubricating oil supply units) 4 are fixed integrally with the support ring 3 between the support rings 3 adjacent to each other in the circumferential direction. An introduction port 4 a is opened on the outer peripheral side of the oil supply nozzle 4 so as to face the inner peripheral surface 2 b of the housing 2 in order to introduce the lubricating oil supplied from the oil supply hole and flowing through the gap C into the oil supply nozzle 4. ing. In addition, on the inner peripheral side of the oil supply nozzle 4, a plurality of lubricants (this embodiment) are opposed to the outer peripheral surface 10 a in order to eject the lubricating oil introduced into the oil supply nozzle 4 toward the outer peripheral surface 10 a of the rotating shaft 10. In the embodiment, seven oil supply ports 4b are opened along the direction of the axis O (see FIG. 3).

  A pivot 7 that protrudes toward the inner peripheral side is fixed integrally with the support ring 3 at a substantially central portion of the inner peripheral surface 3b of the support ring 3. The tip on the inner peripheral side of the pivot 7 has a substantially hemispherical shape. There is no.

  Between the oil supply nozzles 4 adjacent to each other in the circumferential direction, a bearing pad 6 having a pad body 5 swings on the pad mounting surface 5a, which is the outer peripheral surface, with the tip on the inner peripheral side of the pivot 7 as a fulcrum. The support ring 3 is point-supported by a pivot 7 so as to be freely movable. Therefore, misalignment between the rotating shaft 10 and the bearing device 1 (the gap between the outer peripheral surface 10a of the rotating shaft 10 in the radial direction of the axis O and the pad support surface 5b which is the inner peripheral surface of the pad body 5). When F is in a non-uniform state, the bearing pad 6 (pad body 5) can follow the rotating shaft 10. The pad body 5 is only in contact with the pivot 7, and a gap D in the radial direction of the axis O is provided between the pad mounting surface 5 a of the pad body 5 and the inner peripheral surface 3 b of the support ring 3. It has been.

  Each pad body 5 has an arcuate cross section perpendicular to the axis O and a curved plate shape that is wide in the direction of the axis O. Further, a plurality (four in this embodiment) of pad bodies 5 are arranged in the circumferential direction of the axis O. Further, one corresponding pad body 5 is disposed on the inner side in the radial direction of the axis O of one support ring 3. A plurality of pivots 7 for supporting the pad main body 5 are also arranged (four in this embodiment) so as to correspond to the pad main body 5 on a one-to-one basis.

  The radius of curvature of the pad support surface 5 b of the pad body 5 is slightly larger than the radius of curvature of the outer peripheral surface 10 a of the rotating shaft 10. That is, the entire pad support surface 5 b does not come into contact with the outer peripheral surface 10 a of the rotating shaft 10. The pad support surface 5b is made of a soft metal such as white metal (babbit metal).

  Further, there is a gap E between the rotation P-direction end 5c (end 5c1 at the front of the rotation P direction and end 5c2 at the rear of the rotation P direction) of the pad body 5 and the rotation P-direction end 4c of the oil supply nozzle 4. Are provided. The gap E together with the gap D is set to a dimension range in which the pad main body 5 can swing, that is, a dimension range in which the pad main body 5 does not come into contact with the support ring 3 and the oil supply nozzle 4 when the pad main body 5 swings. Has been.

  Further, as described above, a gap F in the radial direction of the axis O is formed between the pad support surface 5 b of the pad body 5 and the outer peripheral surface 10 a of the rotating shaft 10. The oil supply nozzle 4 fixed to the support ring 3 supplies lubricating oil to the gap F from an oil supply port 4b located between the pad bodies 5 adjacent to each other. The pad main body 5 can rotate the rotation shaft 10 around the axis O by the pad support surface 5b from the outer peripheral side (the outer peripheral surface 10a side) of the rotation shaft 10 by interposing the lubricating oil in the gap F. I support it to be.

  Further, a gap G (see FIG. 5) is formed between the side surfaces 3d, 4d, and 5d of the support ring 3, the oil supply nozzle 4, and the pad main body 5 in the direction of the axis O and the side plate 2c that is erected inward in the radial direction of the housing 2. 3) is formed. That is, the gap G is formed toward both ends of the support ring 3, the oil supply nozzle 4, and the pad body 5 in the direction of the axis O.

  As shown in FIGS. 3 to 5, the pad main body 5 is formed such that the shape of the pad mounting surface 5a and the shape of the pad support surface 5b opposite to the pad mounting surface 5a are the same.

  In the present embodiment, the end 5c2 of the pad mounting surface 5a and the pad support surface 5b on the rear side in the rotation P direction is a straight line extending in the axis O direction. Further, the front end 5c1 of the pad mounting surface 5a and the pad support surface 5b in the rotation P direction is formed in an arc shape that swells toward the front side in the rotation P direction.

  In other words, both edge portions of the pad support surface 5b and the pad mounting surface 5a on the outer side in the width direction (both sides in the axis O direction) are formed so as to approach each other toward the front side in the rotation P direction.

  Next, the operation of the bearing device 1 using the bearing pad 6 of the present embodiment will be described.

  The high-pressure and low-temperature lubricating oil supplied from the lubricating oil supply source and the lubricating oil supply pump flows into the gap C through the oil supply hole opened in the housing 2. The lubricating oil that has flowed into the gap C flows into the oil supply nozzle 4 through the introduction port 4a and also flows into the gap G while flowing mainly along the gap C in the circumferential direction. The lubricating oil flowing into the gap G flows into the gap F through the gaps D and E.

  The lubricating oil that has flowed into the oil supply nozzle 4 flows through the oil supply nozzle 4 toward the inner peripheral side, and is then ejected from the oil supply port 4 b toward the outer peripheral surface 10 a of the rotating shaft 10. The low-temperature lubricating oil ejected toward the outer peripheral surface 10 a is caught in the rotation of the rotary shaft 10 and guided into the gap F.

  Thus, the lubricating oil that has flowed into the gap F flows mainly toward the front side in the rotation P direction of the rotating shaft 10. That is, the flow direction of the lubricating oil (arrow Q shown in FIG. 2) is the direction of rotation P of the rotating shaft 10.

  Note that the gap F at this time is filled with lubricating oil, but the pad support surface 5b of each pad body 5 is almost stationary, whereas the rotating shaft 10 side rotates at a very high peripheral speed, so it is narrow. The lubricating oil filled in the gap F has a very large speed difference between the rotating shaft 10 side and the pad body 5 side. When such a speed difference occurs, a shearing force acts on the lubricating oil, and a viscous force is generated inside the lubricating oil. The wedge effect is generated by the viscous action, the rotation shaft 10 and the inclination formed by the movement of each pad body 5, and the oil film pressure is generated in the lubricating oil in the gap F to support the rotation shaft 10. Can do.

  Here, a pressure contour line is shown by a solid line on the pad support surface 5b of the pad body 5 of FIG. As can be seen from FIG. 3, the pressure distribution applied to the pad support surface 5 b of each pad body 5 has a shape corresponding to the shape of the end of the pad body 5. That is, the pressure contour line has a straight line shape in the direction of the axis O on the rear end 5c2 side in the rotation P direction, a straight line shape in the rotation P direction on the side surface 5d side, and the front side in the rotation P direction. On the end 5c1 side, the pad body 5 has a curved shape that swells toward the inner side in the width direction (center side in the axis O direction).

  Similar to this pressure distribution, due to the shearing force acting on the lubricating oil due to the speed difference between the rotating shaft 10 side and the pad main body 5 side, heat is generated along with the viscous force inside the lubricating oil, and the pad main body 5 causes a temperature difference on the pad support surface 5b.

  Here, the temperature distribution is indicated by a two-dot chain line on the pad support surface 5b of the pad body 5 of FIG. As can be seen from FIG. 3, in the pad support surface 5b, the end 5c2 at the rear in the rotation P direction (upstream side in the flow direction of the lubricant) is directed to the end 5c1 at the front in the rotation P direction (downstream in the flow direction of the lubricant). As the temperature increases. Further, the isotherm at the end portion 5c1 has a curved shape that swells toward the inner side in the width direction of the pad body 5 (center side in the axis O direction) corresponding to the shape of the end portion 5c1.

  On the other hand, the lubricating oil at this time has a lubricating action between the rotary shaft 10 and each pad body 5 and also a cooling action for each pad body 5. That is, the low-temperature lubricating oil ejected from the oil supply opening 4b of each oil supply nozzle 4 toward the outer peripheral surface 10a of the rotary shaft 10 passes through the gap F in the direction of the rotation P (the lubricant oil) in the gap F as described above. Each of the pad bodies 5 is convectively cooled from the pad support surface 5b side when flowing along the flow direction. Therefore, the lubricating oil moves from the end 5c2 on the pad support surface 5b rearward in the rotation P direction (upstream side in the flow direction of the lubricating oil) toward the end 5c1 on the front side in the rotation P direction (downstream side in the flow direction of the lubricating oil). Therefore, heat is exchanged with the pad body 5 and the temperature gradually rises.

  And the lubricating oil which became high temperature is the direction orthogonal to a pressure contour from the edge part 5c1 ahead of the rotation P direction of the pad main body 5, that is, the width direction outer side of the pad main body 5, and the rotation P direction front direction of the rotating shaft 10 ( Flows in the direction of the arrow shown in FIG.

According to the steam turbine 20 thus configured, the pad support surface 5b and the end 5c1 of the pad mounting surface 5a on the front side of the rotation P direction of the rotation shaft 10 swell toward the front side in the rotation P direction. Is formed. As a result, the lubricating oil interposed between the pad support surface 5b and the rotary shaft 10 moves from the front end 5c1 of the pad main body 5 in the rotational P direction to the outside in the width direction of the pad main body 5 and in the rotational P direction of the rotary shaft 10. It flows toward the front and flows into the gap E and the gap G. Further, the lubricating oil can flow into the gap E and the gap G over the radial direction from the pad mounting surface 5a to the pad support surface 5b.
Here, this embodiment is compared with a configuration in which the end portion 5c1 of the pad main body 5 is formed in a linear shape toward the axis O direction. When the end portion 5c1 is formed in a straight line toward the axis O direction, the pressure contour in front of the pad support surface 5b in the rotation P direction is substantially parallel to the axis O direction. It flows toward the orthogonal direction, that is, toward the gap E. On the other hand, in the present embodiment, the lubricating oil flows from the end portion 5c1 to the outer side in the width direction of the pad body 5 and forward in the rotation P direction of the rotation shaft 10, that is, toward the gap G. Therefore, in this embodiment, the lubricating oil which flows toward the clearance gap E can be suppressed rather than the case where said edge part 5c1 is formed in the linear form which goes to the axis line O direction.
Further, since the amount of the lubricating oil that has flowed out into the gap E is suppressed, it flows as carry-over oil between the pad support surface 5b of the pad main body 5 disposed in front of the rotation P direction and the rotary shaft 10. Rather, it flows through the gap G between the oil supply nozzle 4 and the side plate 2c toward the front side in the rotation P direction.
In this way, the lubricating oil that has become hot is heated at the end 5c1 of the pad body 5 from between the rotary shaft 10 and the pad support surface 5b toward the outside in the width direction and forward in the rotation P direction of the rotary shaft 10. It becomes possible to efficiently discharge the lubricating oil. Furthermore, since the pad main body 5 arranged in front of the rotation P direction can be cooled with the lubricating oil supplied from the oil supply nozzle 4 arranged in front of the rotation P direction, thermal stress and thermal deformation generated in the pad main body 5 can be reduced. Can be relaxed.

(Modification 1 of the first embodiment)
As shown in FIG. 6, in the pad main body 105 that is Modification 1 of the first embodiment, the front end 105 c 1 of the pad mounting surface 5 a and the pad support surface 5 b in the rotation P direction is both in the width direction of the pad main body 105. A pair of arc portions 116 and 116 having an arc shape as viewed from the radially inner side that swells outward in the width direction and forward in the rotation P direction at the edge portion, and a connecting portion 117 that connects the pair of arc portions 116 and 116. doing.

  In the pad main body 105 configured as described above, the pressure contour line on the front side in the rotation P direction of the pad support surface 5b is a line corresponding to the shape of the end portion 105c1. Therefore, the high-temperature lubricating oil flows from the pair of arc portions 116, 116 in a direction substantially orthogonal to the arcs of the arc portions 116, 116, that is, in the width direction outside and in the forward direction of the rotation P direction (the direction of the arrow shown in FIG. 6). It is discharged towards.

(Modification 2 of the first embodiment)
As shown in FIG. 7, in the pad main body 205 that is the second modification of the first embodiment, the front end 205c1 of the pad mounting surface 5a and the pad support surface 5b in the rotation P direction are both in the width direction of the pad main body 205. A pair of inclined portions 206 and 206 that are formed so as to gradually move forward toward the inner side in the width direction at the edge portion, and a connecting portion 207 that connects the pair of inclined portions 206 and 206 as viewed from the inner side in the radial direction; have.

  In the pad main body 205 configured as described above, the pressure contour line on the front side in the rotation P direction of the pad support surface 5b is a line corresponding to the shape of the end portion 205c1. Therefore, the high-temperature lubricating oil flows from the pair of inclined portions 206 and 206 in a direction substantially orthogonal to the straight line of the inclined portions 206 and 206, that is, in the width direction outer side and in the forward direction of the rotation P direction (the direction of the arrow shown in FIG. 7). It is discharged towards.

(Modification 3 of the first embodiment)
As shown in FIG. 8, in the pad main body 305 that is the third modification of the first embodiment, the front end portion 305 c 1 of the pad mounting surface 5 a and the pad support surface 5 b in both the width directions of the pad main body 305. The edge portion has a pair of inclined portions 306 and 306 that are formed so as to gradually go forward as they go inward in the width direction, as viewed from the inside in the radial direction. The ends of the pair of inclined portions 306 and 306 are connected to each other.

  In the pad main body 305 configured as described above, the pressure contour line on the front side in the rotation P direction of the pad support surface 5b is a line corresponding to the shape of the end portion 305c1. Therefore, the high-temperature lubricating oil flows from the pair of inclined portions 306, 306 in a direction substantially orthogonal to the straight line of the inclined portions 306, 306, that is, in the width direction outer side and the forward direction in the rotation P direction (the direction of the arrow shown in FIG. It is discharged towards.

(Modification 4 of the first embodiment)
As shown in FIG. 9, the bearing pad 406 of Modification 4 of the first embodiment includes a pad body 405A as a plurality of pad bodies 405, and a pad body 405B disposed in front of the pad body 405A in the rotation P direction. A pad body 405A disposed in front of the pad body 405B in the rotation P direction.

  The pad main body 405A is formed so as to gradually go forward in the rotational P direction as it goes inward in the width direction at one edge in the width direction of the end portion 405c1 of the pad mounting surface 5a and the pad support surface 5b in the rotational P direction front. In addition, a linear inclined portion 406A viewed from the radially inner side and a linear straight portion 407A viewed from the radially inner side extending in the axis O direction from the end of the inclined portion 406A are provided.

  The pad main body 405B is formed so as to gradually go forward in the rotational P direction as it goes inward in the width direction at the edge of the other side in the width direction of the end portion 405c1 of the pad mounting surface 5a and the pad support surface 5b in the rotational P direction front. The linear inclined portion 406B as viewed from the radially inner side, and the linear straight portion 407B as viewed from the radially inner side extending in the axis O direction from the end of the inclined portion 406B.

  Thus, the pad main body 405A and the pad main body 405B are alternately arranged in the rotation P direction.

  In the bearing pad 406 configured as described above, the pressure contour line on the front side in the rotation P direction of the pad support surface 5b is a line corresponding to the shape of the end portion 405c1. Accordingly, the high-temperature lubricating oil is discharged from the inclined portions 406A and 406B in a direction substantially orthogonal to the straight line of the inclined portions 406A and 406B, that is, outward in the width direction and forward in the rotation P direction.

  Further, in the pad main body 405A, the lubricating oil is discharged from the inclined portion 406A provided on one side in the width direction, and in the pad main body 405B, the lubricating oil is discharged from the inclined portion 406B provided on the other side in the width direction. It can discharge alternately with the width direction one side and the other side. Therefore, since the high-temperature lubricating oil can be discharged with a good balance in the width direction, the temperature difference in the direction of the axis O of the lubricating oil can be suppressed.

(Second embodiment)
Hereinafter, the pad main body 505 according to the second embodiment of the present invention will be described with reference to FIG.
In this embodiment, the same members as those used in the above-described embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  The steam turbine according to the present embodiment is obtained by changing the bearing pad 6 of the steam turbine 20 according to the first embodiment, and other configurations are the same as those of the steam turbine 20 according to the first embodiment.

  In the pad main body 505 according to the present embodiment, the shape of the pad support surface 505b and the shape of the pad mounting surface 505a are different from each other.

  The front end 505c1 of the pad support surface 505b in the rotation P direction is formed in an arc shape that swells toward the front side in the rotation P direction. Further, the end 505d1 of the pad mounting surface 505a on the front side in the rotation P direction is formed in an arc shape that swells toward the front side in the rotation P direction.

  The shape of the end portion 505c1 of the pad support surface 505b corresponds to the shape of the end portion 505d1 of the pad mounting surface 505a. Further, the end portion 505d1 of the pad mounting surface 505a is formed to be positioned forward in the rotation P direction across the width direction than the end portion 505c1 of the pad support surface 505b. That is, the area of the pad attachment surface 505a is larger than the area of the pad support surface 505b.

  The end portion 505c1 of the pad support surface 505b and the end portion 505d1 of the pad mounting surface 505a are connected to each other by a connecting wall portion 506. The connecting wall portion 506 is formed so as to gradually go forward in the rotational P direction as it goes radially outward.

  In the pad main body 505 configured as described above, the pad mounting surface 505a has a larger area than the pad support surface 505b, so that the pad main body 505 is securely supported and attached to the pivot 7. Further, the lubricating oil having reached a high temperature is discharged from the end portion 505c1 of the pad support surface 505b along the connecting wall portion 506, that is, gradually toward the front side in the rotation P direction as it goes radially outward. Accordingly, since the high-temperature lubricating oil flows radially outward in the gap E and the gap G in the rotation P direction of the pad main body 505 toward the rotation P direction, the pad support of the pad main body 505 disposed in front of the rotation P direction is performed. It does not flow into the surface 505b.

(Modification 1 of the second embodiment)
As shown in FIG. 11, in the pad main body 605 that is the first modification of the second embodiment, the front end 605c1 of the pad support surface 605b in the rotation P direction is formed in a straight line extending in the axis O direction. Yes. Further, the end 605d1 of the pad mounting surface 605a on the front side in the rotation P direction is formed in an arc shape that swells toward the front side in the rotation P direction. Further, the area of the pad mounting surface 605a is larger than the area of the pad support surface 605b.

  The end 605c1 of the pad support surface 605b and the end 605d1 of the pad mounting surface 605a are connected to each other by a connecting wall 606. The connecting wall portion 606 is formed so as to gradually go to the front side in the rotation P direction as it goes outward in the radial direction.

  In the pad main body 605 configured as described above, since the area of the pad mounting surface 605a is larger than the area of the pad support surface 605b, the pad main body 605 is securely supported and attached to the pivot 7. Further, the lubricating oil having reached a high temperature is discharged from the end portion 605c1 of the pad support surface 605b along the connecting wall portion 606, that is, gradually toward the front side in the rotation P direction as it goes radially outward. Accordingly, since the high-temperature lubricant flows in the radial direction outer side of the gap E and the gap G in the rotation P direction of the pad main body 605 toward the rotation P direction, the pad support of the pad main body 605 disposed forward of the rotation P direction is performed. It does not flow into the surface 605b.

(Modification 2 of the second embodiment)
As shown in FIG. 12, in the pad main body 705 which is the second modification of the second embodiment, the front end 705c1 of the pad support surface 705b in the rotation P direction is formed in an arc shape that swells toward the front side in the rotation P direction. Has been. Further, an end portion 705d1 of the pad mounting surface 705a on the front side in the rotation P direction is formed in a straight line extending toward the axis O direction. Further, the area of the pad attachment surface 705a is larger than the area of the pad support surface 705b.

  The end portion 705c1 of the pad support surface 705b and the end portion 705d1 of the pad mounting surface 705a are connected to each other by a connecting wall portion 706. The connecting wall portion 706 is formed so as to gradually go to the front side in the rotation P direction as it goes outward in the radial direction.

  In the pad main body 705 configured as described above, since the area of the pad mounting surface 705a is larger than the area of the pad support surface 705b, the pad main body 705 is securely supported and attached to the pivot 7. Further, the lubricating oil having reached a high temperature is discharged from the end portion 705c1 of the pad support surface 705b along the connecting wall portion 706, that is, gradually toward the front side in the rotation P direction as it goes radially outward. Accordingly, since the high-temperature lubricating oil flows in the radial direction outer side of the gap E and the gap G in the rotation P direction of the pad main body 705 toward the rotation P direction, the pad support of the pad main body 705 disposed forward of the rotation P direction is performed. It does not flow into the surface 705b.

  The various shapes and combinations of the constituent members shown in the above-described embodiments are merely examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.

  For example, in the present embodiment, the bearing pad 6 is described as being supported by the pivot 7. However, the present invention is not limited to this, and the bearing pad 6 is axially extended by a member extending in the direction of the axis O. The structure supported over O direction may be sufficient.

DESCRIPTION OF SYMBOLS 1 ... Bearing apparatus 2 ... Housing 5,105,205,305,405,405A, 405B, 505,605,705 ... Pad main body 5a, 505a, 605a, 705a ... Pad mounting surface 5b, 505b, 605b, 705b ... Pad support Surface 6,406 ... bearing pad 10 ... rotating shaft 10a ... outer peripheral surface 20 of rotating shaft ... steam turbine (rotary machine)
506, 606, 706 ... connecting wall F ... gap O ... axis

Claims (4)

A housing;
A plurality of rotating shafts are supported in the housing so as to be swingable, and are arranged in the circumferential direction of the rotating shaft that rotates about the axis. Lubricating oil is interposed in the gap with the outer peripheral surface of the rotating shaft, so that the rotating shaft is has a pad body for supporting from the side by the pad support surface, gradually from one another according to opposite edges of the both sides in the axial direction in the rotation direction front side of the rotation axis of the pad support surface, toward the front Symbol rotation direction front side Bearing pads that are close to each other and are connected to each other in front of the rotational direction;
A lubricating oil supply section that supplies the lubricating oil to the gap from between the bearing pads adjacent to each other ,
The shape of the pad mounting surface that is the back surface of the pad support surface and the shape of the pad support surface are different from each other,
The bearing device, wherein the pad support surface and the pad mounting surface are connected to each other by a connecting wall portion formed so as to gradually go to the front side in the rotational direction as going outward in the radial direction . The bearing device according to claim 1,
An end portion of the pad support surface on the front side in the rotation direction is formed in an arc shape that swells toward the front side in the rotation direction. In the bearing device according to claim 1 or 2,
The bearing device, wherein the shape of the pad mounting surface that is the back surface of the pad support surface and the shape of the pad support surface are the same. The rotating shaft;
A rotary machine comprising the bearing device according to any one of claims 1 to 3 that rotatably supports the rotating shaft.

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