JP4848413B2 - Rotating structure with journal bearing - Google Patents

Description

  INDUSTRIAL APPLICABILITY The present invention is suitable for being applied to large rotating machines such as steam turbines and generators, and is a rotating structure that enables formation of a high oil film pressure of lubricating oil on the upper pad bearing surface of a pad type journal bearing that supports a rotating shaft. About the body.

Conventionally, for this type of journal bearing, a journal bearing having a tilting pad capable of automatically aligning the journal is used.
Japanese Patent Laid-Open No. 5-332355 discloses a journal bearing provided with a tilting pad proposed by the present applicant. As disclosed in Patent Document 1, the tilting pad can swing in the axial direction and the circumferential direction of the journal through an adjustment liner on a spherical pivot provided on the back side of the tilting pad with respect to the journal. It is supported.

Therefore, the tilting pad can move freely with respect to the movement of the journal, and the journal bearing provided with the tilting pad has a self-aligning function. For this reason, the journal can be stably supported, so that it is applied to a high-speed rotating machine.
In addition, the spherical pivot protrudes from the inner surface of the bearing housing toward the tilting pad and loosely fits in a groove provided on the back of the tilting pad, so that the tilting pad rotates in the journal rotation direction. It is blocked by the pivot.

Journal bearings with tilting pads are classified into oil bath lubrication and direct lubrication. The oil bath lubrication method is a method in which both sides of the tilting pad are sealed with side seals, and the bearing surface of the tilting pad is filled with lubricating oil.
However, this method has a problem that the frictional loss due to the side seal and the agitation loss of the lubricating oil between the pads occur, and the mechanical efficiency is lowered.

  This reduction in mechanical efficiency will be described with reference to FIG. FIG. 8 is a diagram showing the relationship between the journal rotation speed and the mechanical loss of the journal bearing in the oil bath lubrication method shown in FIG. In FIG. 8, the total mechanical loss increases approximately in proportion to the square of the rotational speed. The breakdown is the friction loss X due to the lower pad on the load side and the friction loss Y due to the upper pad on the no load side. The mechanical loss Z is the sum of the friction loss due to the side seal and the stirring loss of the lubricating oil between the pads.

  Therefore, a direct lubrication method that eliminates the mechanical loss Z has been proposed. The direct lubrication method is a method in which an oil supply nozzle is provided on the upstream side of each tilting pad in the journal rotation direction, and lubricating oil is supplied from the oil supply nozzle to the bearing surface of the tilting pad, and the side seal is removed. is there. The direct lubrication system is widely used at present because the mechanical loss Z can be eliminated. Patent Document 1 proposes a journal bearing of a direct lubrication method.

  Patent Document 2 (Japanese Patent Laid-Open No. 2000-274432) proposes a journal bearing of a direct lubrication system having another configuration. As described in paragraph [0009] of Patent Document 2, the journal bearing provided with the tilting pad also has a problem of carryover of lubricating oil. This is a phenomenon in which the lubricating oil supplied to the bearing surface of the upstream tilting pad rotates along with the journal surface and enters the bearing surface of the downstream tilting pad.

Lubricating oil receives a shearing force on the bearing surface of the tilting pad, and the temperature rises. Therefore, the lubricating oil enters a bearing surface of the plurality of tilting pads and becomes high temperature. And the temperature of a tilting pad may be raised and the bearing part may be burned out.
Patent Document 2 proposes a means for preventing carryover in a journal bearing of a direct lubrication system.

Further, as described in paragraph [0004] of Patent Document 2, in the pad-type journal bearing, the lubricating oil is filled between the journal surface and the tilting pad, but the tilting pad is fixed, and the journal Is rotating at a very high peripheral speed, a large speed difference occurs between the tilting pad and the journal bearing.
Against this speed difference, it is necessary to form an oil film pressure that supports the load applied to the tilting pad between the journal surface and the tilting pad.

  FIG. 9 is a quotation of FIG. 33 of Patent Document 2. In FIG. 9, a plurality of tilting pads 101 a to 101 d are arranged between the journal 100 and the ring-shaped bearing housing 103 so as to surround the journal 100, and support the journal 100. A gap 102 between the journal 100 and the tilting pads 101a to 101d is filled with lubricating oil. The oil film pressure Fp varies depending on the direction and position of the load W applied to the journal 100. When the oil film pressure Fp generated in each of the tilting pads 101a to 101d is integrated over the entire circumference, the oil film pressure Fp matches the load W of the journal 100.

  By tilting each tilting pad 101a to 101d and narrowing the gap 102 on the downstream side in the journal rotation direction a, a high oil film pressure can be formed in the gap 102 on the downstream side due to the wedge film effect.

JP-A-5-332355 JP 2000-274432 A

Since the journal weight is added to the bearing surface of the tilting pad disposed on the lower side of the journal, it is relatively easy to form a high oil film pressure. However, it is not easy to form a high oil film pressure on the bearing surface of the tilting pad disposed on the upper side of the journal because the weight of the journal is not added.
Even when the wedge film effect is exerted by narrowing the clearance downstream of the tilting pad and the journal in the rotational direction, the large rotating structure increases the weight of the tilting pad. It is not easy to adjust the gap.

  In view of the problems of the prior art, the present invention makes it possible to adjust a gap between a journal and a tilting pad, which is arranged on the upper side of the journal and does not add the journal's own weight, in the rotary structure including the journal bearing. The object is to facilitate the formation of a high oil film pressure of the lubricating oil over the entire circumference.

In order to achieve the above object, a rotating structure including a journal bearing according to the present invention has a plurality of pads that are swingably disposed in an annular bearing housing and support the journal so as to be self-aligning. In a rotating structure having a journal bearing in which lubricating oil is supplied between the pad and the journal, the central area of the pad is swung in a spherical pivot provided on the inner surface of the bearing housing in the axial direction and the circumferential direction of the journal. In a bearing housing that is movably supported and supports an upper pad disposed at an upper position where the journal's own weight is not loaded, a measurement hole penetrating from the back surface of the spherical pivot to the outer surface of the bearing housing is provided, the measurement hole and configured to adjust the gap between the journal and the upper pad based from the opening to a depth measurement of up to spherical pivot back Than is.

According to the present invention, it is difficult to form a high oil film pressure in the gap between the upper pad and the journal where the journal's own weight is not loaded. Therefore, vibration is likely to be generated in the upper pad, which may cause the inner surface of the upper pad to contact the journal and cause cracks in the upper pad.
With the above configuration, the gap between the upper pad and the journal can be accurately adjusted in the journal rotation direction, so that a high oil film pressure can be formed in the gap between the upper pad and the journal, and therefore the vibration of the upper pad is generated. Can be prevented.
In the present invention, it is preferable that the downstream portion of the upper pad in the journal rotation direction is pressed toward the journal by the elastic force of the spring member . A narrowing gap can be formed between the upper pad and the journal toward the downstream side in the rotational direction. Therefore, a high oil film pressure due to the lubricating oil can be formed on the bearing surface of the upper pad by the wedge film effect, so that the lubricating performance of the bearing surface can be maintained and the bearing surface can be prevented from being burned out.

  In the present invention, it is preferable that lift means that can lift the upstream end of the upper pad in the journal rotation direction is provided, and that the clearance between the upper pad and the upstream portion of the journal in the rotation direction can be adjusted by the lift means. By the combination of the spring member and the lift means, the gap between the upper pad and the journal can be accurately adjusted to a desired dimension over the journal rotation direction.

  In the present invention, the lift means includes a through hole formed in the bearing housing in the radial direction and a screw hole formed in the pad and opened in a position connected to the through hole and formed in the same direction. A bolt inserted into the through-hole and simultaneously screwed into the screw hole, and a gap between the bearing housing and the pad can be adjusted by adjusting a screwing length of the bolt into the screw hole. Good.

  With this configuration, the lift means can be made simple and low-cost, and the lift means can be used as a means for simultaneously conveying the bearing housing and the pad by integrally forming a hanging portion on the bolt.

According to the rotating structure including the journal bearing of the present invention, the rotary structure has a plurality of pads which are swingably disposed in the annular bearing housing and support the journal so as to be self-alignable, and between the pads and the journal. In a rotating structure with a journal bearing that supplies lubricating oil to
A central area of the pad is supported on a spherical pivot provided on the inner surface of the bearing housing so as to be swingable in the axial direction and the circumferential direction of the journal, and an upper pad disposed at an upper position where the weight of the journal is not loaded is supported. In the bearing housing, a measurement hole penetrating from the rear surface of the spherical pivot to the outer surface of the bearing housing is provided, and a gap between the journal and the upper pad is formed based on a depth measurement value from the opening of the measurement hole to the rear surface of the spherical pivot. with the arrangements to condition, since it accurately adjusted over the gap between the upper pad and the journal in the journal direction of rotation, can form a high oil film pressure in the gap between the upper pad and the journal, therefore, the vibration of the upper pad Can be prevented.

  Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the component parts described in this embodiment are not intended to limit the present invention to that only, unless otherwise specified.

1 to 3 show a journal bearing of the present embodiment, FIG. 1 is a front sectional view taken along line CC in FIG. 2, and FIG. 2 is a side sectional view taken along line BB in FIG. FIG. 3 and FIG. 3 are rear views seen from the direction A in FIG.
In FIG. 1, a journal j is a rotating shaft of a large rotating machine such as a steam turbine, a gas turbine, or a generator. Since the journal j has a large diameter of about 40 cm, the journal bearing 10 that supports the journal j is enlarged and the peripheral speed of the journal j is also increased. Journal j rotates in the direction of arrow a.

  The journal bearing 10 that supports the journal j includes a bearing base 20, a split-type bearing housing 30 that is fixedly supported by the bearing base 20, and a tilting pad 40 that is attached to the inner surface of the bearing housing 30. Yes. The bearing base 20 has a recess 20a having a semicircular cross section, while the split bearing housing 30 is divided into an upper bearing housing 30a and a lower bearing housing 30b each having a semi-ring shape. The lower bearing housing 30b is fitted and fixed to the recess 20a. The upper bearing housing 30 a is positioned on the lower bearing housing 30 b with the positioning pins 31 shown in FIG. 3 and is coupled to the lower bearing housing 30 b by the coupling bolt 32.

  Inside the bearing housing 30, four tilting pads 40a to 40d are arranged in the circumferential direction. In addition, when description common to all the tilting pads is performed, a to d are omitted and displayed. The same applies to other members. As shown in FIG. 4, a recess 42 is formed near the center of the back surface of each tilting pad 40, and an adjustment liner 44 is press-fitted into the recess. A recess 34 is provided on the inner surface of the bearing housing facing the adjustment liner 44, and a spherical pivot 36 is fitted in the recess.

The surface of the spherical pivot 36 is formed in a spherical shape, and the tilting pad 40 can swing in the circumferential direction and the axial direction of the journal j along the spherical surface. Between the tilting pads 40, gaps s1 are provided at equal intervals. The center point of the spherical pivot 36 is arranged at a circumferential position of 45 degrees from the vertical direction or the horizontal direction.
The spherical surface of the spherical pivot 36 is formed at the same height as the inner peripheral surface of the bearing housing 30. Therefore, when the side plate 35 described later is removed, the tilting pad 40 can be removed from the bearing assembly by sliding the tilting pad 40 in the journal axis direction with the adjustment liner 44 attached.

The upper bearing housing 30a is formed with a measurement hole 38 that communicates the recess 34 and the outer peripheral surface of the upper bearing housing 30a in the radial direction of the journal j. An outer liner 33 is provided on the outer peripheral surface of the bearing housing 30 that is in the same circumferential position as the circumferential position where the spherical pivot 36 is provided.
As shown in FIG. 4, the outer liner 33 is coupled to the outer peripheral surface of the bearing housing 30 by a coupling bolt (not shown). The outer peripheral surface of the outer liner 33 protrudes slightly outward from the outer peripheral surface of the bearing housing 30.

Therefore, the outer liner 33 is in contact with the bearing base 20, and the lower bearing housing 30 b is fixedly supported on the bearing base 20 via the outer liner 33. A gap s <b> 2 exists between the outer peripheral surface of the upper bearing housing 30 a and the inner peripheral surface of the bearing stand 20.
The outer liner 33 is formed with a through hole 33 a communicating with the measurement hole 38. The measurement hole 38 is closed with a plug 39 after a predetermined measurement operation is completed.

  As shown in FIG. 2, ring-shaped side plates 35 are disposed on both sides of the bearing housing 30 and the tilting pad 40 in the journal axis direction over the entire circumference. As shown in FIG. 3, the side plate 35 is coupled to the bearing housing 30 with a plurality of bolts 37 arranged in the circumferential direction. A gap s3 is provided between the side plate 35 and the journal j. Lubricating oil ejected from an oil supply nozzle 50, which will be described later, is used for lubrication between the journal j and the tilting pad 40 and is then discharged from the gap s3.

  As shown in FIG. 1, the oil supply nozzles 50 that eject the lubricating oil are disposed in front of and behind the journaling direction of the tilting pads 40 so as to sandwich the respective tilting pads 40. FIG. 5 shows, as an example, an oil supply nozzle 50 arranged behind the tilting pad 40 in the journal rotation direction. The configuration of the fueling nozzle 50 will be described with reference to FIGS. The oil supply nozzle 50 has no structural difference due to the difference in the upstream or downstream side of the journal rotation direction.

  The lower half of the main casing 52 having a rectangular parallelepiped shape is fitted and fixed to the fitting recess 70 provided in the bearing housing 30, and the upper half of the oil supply nozzle 50 stands from the bearing housing 30 toward the tilting pad 40 side. It is installed. Arms 54 extend from the main casing 52 on both sides in the journal axial direction. Lubricating oil supply holes 56 are formed in the main casing 52 and the arms 54.

  A plurality of nozzle openings 58 are formed in the arm 54 at equal intervals in the axial direction, and the nozzle openings 58 are directed to the journal j side. Lubricating oil ejected from an oil supply nozzle 50 provided on the upstream side of the journal rotation direction with respect to the tilting pad 40 is caused by the rotational force of the journal j and the inner peripheral surface of the tilting pad 40 (bearing surface 48 in FIG. 4) and the journal. An oil film is formed between the outer peripheral surfaces of j.

  The lubricating oil ejected from the oil supply nozzle 50 provided on the downstream side in the journal rotation direction with respect to the tilting pad 40 cools the lubricating oil that has passed between the tilting pad 40 and the journal j, and the flow of the lubricating oil is reduced. By disturbing with the lubricating oil ejected from the nozzle port 58 and separating it from the journal surface, it is prevented from rotating around the bearing surface 48 of the tilting pad 40 on the rear side in the rotation direction. The lubricating oil is discharged from the gap s3 between the side plate 35 and the journal j.

  As shown in FIG. 5, the main casing 52 is a rectangular parallelepiped, and the surface 52a and the inclined surface 46 of the main casing 52 and the tilting pad 40 that face each other are in line contact with each other at the root portion 46a. , And is inclined so as to form a minute angle α in a direction away from the surface 52a. In this manner, the oil supply nozzle 50 is supported by the surface 52a of the main casing 52 from both sides of the journaling direction of the tilting pad 40 in line contact with the root portion 46a of the inclined surface 46 of the tilting pad 40, thereby tilting. The movement of the pad 40 in the journal rotation direction is fixedly supported.

As shown in FIG. 1, the bearing base 20 is provided with a lubricating oil supply hole 60. An outer liner 62 is provided on the outer peripheral surface of the lower bearing housing 30 b facing the oil supply hole 60. Hereinafter, the configuration of this portion will be described with reference to FIG. In FIG. 6, an oil supply hole 62 a is formed in the outer liner 62 at a position communicating with the oil supply hole 60 in the journal radial direction.
The lower bearing housing 30b is provided with oil supply holes 64 in the radial direction at positions communicating with the oil supply holes 62a. Further, an annular oil guide groove 66 is provided in communication with the oil supply hole 64 in the journal rotation direction.

  The oil guide groove 66 is provided in the entire circumference in the bearing housing 30. As shown in FIG. 2, the oil guide groove 66 is formed in an oil supply hole 56 formed in the main casing 52 of the oil supply nozzle 50 via an oil supply hole 68 formed in the bearing housing 30 in the journal axis direction. Communicate. One end opening of the oil supply hole 56 is closed by a plug 72, and the plug 72 is fixed to the opening by a C-shaped retaining ring 74.

  A gap s4 is formed between the inner surface of the bearing stand 20 and the outer surface of the outer liner 62. The O-ring 76 is inserted into the gap s4, and a crushing margin is provided in the O-ring 76 to seal the gap s4. As a result, the lubricating oil is prevented from leaking from the gap s4, and the load of the lower bearing housing 30b applied to the bearing base 20 via the outer liner 62 is supported via the outer liner 33 that supports the load of the bearing housing 30. It is configured to be smaller than the load of the bearing housing 30 added to the table 20.

  As shown in FIG. 7, cylindrical concave portions 82 are formed in two locations facing the outer peripheral surface of the tilting pad 40a or 40b on the inner peripheral surface of the upper bearing housing 30a. A cylindrical recess 84 having the same diameter as the recess 82 is formed on the outer peripheral surface of the tilting pad 40a or 40b facing the recess 82. A coil spring 80 is fitted into the recess 82 and the recess 84. As a result, the elastic force of the coil spring 80 is urged toward the journal j. The coil spring 80 is provided on the downstream end of the tilting pad 40a or 40b in the journal rotation direction. Therefore, it becomes easy to form a narrow gap between the surface of the journal j and the tilting pad 40a or 40b in the journal rotation direction as shown in FIG.

  As shown in FIG. 1, screw holes 90 are formed in the radial direction at the upstream end and the downstream end in the journal rotation direction of each tilting pad 40. A bolt through hole 92 is formed in a radial direction at a position corresponding to the opening of the screw hole 90 of the bearing housing 30. The screw holes 90 and the bolt through holes 92 are provided so that the axes thereof coincide. A carrying hexagon socket head bolt 94 is passed through the bolt through hole 92 and the tip of the hexagon socket head bolt 94 is screwed into the screw hole 90.

The gap between the bearing housing 30 and the tilting pad 40 can be adjusted by adjusting the length of the threaded portion of the hexagon socket head bolt 94 to the screw hole 90. Thereby, the gap dimension between the journal surface and the tilting pad 40 can be adjusted.
In addition, since the hexagonal hole for inserting a conveyance tool is provided in the head part of the hexagon socket head cap bolt 94, it can utilize also as a conveyance means of the bearing housing 30 and the tilting pad 40. In this way, the clearance between the tilting pad 40 and the journal j at the front and rear ends in the rotational direction can be adjusted with simple and low-cost means.

  In the present embodiment having such a configuration, the lubricating oil is supplied to the oil supply nozzle 50 from the oil supply hole 60 provided in the bearing stand 20 through the oil guide groove 66 and the oil supply holes 68 and 56. Then, the lubricating oil is supplied to the inner peripheral surface (bearing surface 48) of the tilting pad 40 from the nozzle port 58 of the arm 54 of the oil supply nozzle 50.

  Lubricating oil ejected from an oil supply nozzle 50 disposed on the upstream side in the journal rotation direction with respect to the tilting pad 40 is supplied to the bearing surface 48 and is used for lubrication of the bearing surface 48. Lubricating oil ejected from the oil supply nozzle 50 disposed downstream of the journal rotation direction cools the lubricating oil that has passed through the bearing surface 48 and disturbs the laminar flow of the lubricating oil formed on the surface of the journal j. Thus, it is possible to suppress the lubricating oil having a high temperature from rotating around the bearing surface 48 on the downstream side. As a result, the high temperature of the lubricating oil on the bearing surface 48 can be suppressed, and burning of the bearing surface 48 can be suppressed.

At this time, the gap between the bearing surface 48 of the tilting pad and the surface of the journal j can be measured by measuring the distance from the back surface of the spherical pivot 36 to the opening of the measurement hole 38 using a known measuring device. Based on this measured value, as shown in FIG. 4, the gap between the bearing surface 41 and the journal can be adjusted to a desired dimension by inserting a height adjusting shim plate 86 on the back surface of the spherical pivot 36. .
By using this clearance adjustment means together with clearance adjustment by the hexagon socket head cap bolt 94, the clearance between the bearing surface 41 and the journal j is narrowed toward the journal rotation direction with high accuracy as shown in FIG. Since the gap can be formed, a high oil film pressure can be formed on the bearing surface 48 by utilizing the wedge film effect. Therefore, the lubricating performance of the bearing surface 48 can be maintained high.

  Since the own weight of the journal j is loaded on the tilting pads 40c and 40d provided in the lower bearing housing 30b, it is relatively easy to form the narrow gap shown in FIG. On the other hand, since the own weight of the journal j is not loaded on the tilting pads 40a and 40b provided in the upper bearing housing 30a, a higher oil film pressure is formed on the bearing surface 48 with the journal j than the lower bearing housing 30b. It's not easy.

In the present embodiment, the coil spring 80 is provided downstream of the tilting pad 40a or 40b provided in the upper bearing housing 30a in the journal rotation direction, and the elastic force of the coil spring 80 is applied to the journal j. However, it becomes easy to form a narrow gap. Therefore, a high oil film pressure can be easily formed on the bearing surface 48 by utilizing the wedge film effect.
In addition, since the journal j is not loaded with its own weight on the upper bearing housing 30a, vibration tends to occur in the related art, and there is a possibility that fatigue destruction may occur in the tilting pad 40 due to the vibration. Can also be eliminated.

Further, the oil supply nozzle 50 is provided on the upstream side and the downstream side in the rotation direction of each tilting pad 40, and the base part of the inclined surface 46 of the tilting pad 40 is supported in line contact by the base part 46a of the main casing 52. A means for fixing the tilting pad 40 in the journal rotation direction is not required, and the configuration of the journal bearing can be simplified.
Further, since the tilting pad 40 is supported by the base portion 46a of the main casing 52, the front and rear spaces of the tilting pad 40 can be widened, thereby enabling further stable supply of lubricating oil. Become.

  Conventionally, the spherical pivot 36 protrudes toward the tilting pad 40 and the tilting pad 40 is fixed. However, in this embodiment, such a configuration is unnecessary. Therefore, by making the surface of the spherical pivot 36 the same height as the inner peripheral surface of the bearing housing 30, the tilting pad 40 can be pulled out in the journal axis direction simply by removing the side plate 35. Therefore, it is possible to remove the tilting pad 40 with the journal j installed, and it becomes easy to attach and remove the tilting pad 40 when the tilting pad 40 is repaired or modified.

  Further, according to the present embodiment, the outer liner 62 is provided separately from the outer liner 33 that is the load support portion of the bearing housing 30, and the outer liner 62 is provided with the oil supply hole 62 a, thereby preventing the strength of the outer liner 33 from being lowered. Therefore, the thickness of the bearing housing 30 can be prevented. Further, since the load of the bearing housing 30 loaded on the bearing mount 20 by the outer liner 62 is made smaller than the load of the bearing housing 30 loaded on the bearing mount 20 by the outer liner 33, the support points of the bearing housing 30 are increased excessively. There is nothing. Therefore, it is not necessary to make the dimensional accuracy of the load support portion of the bearing housing 30 high, and the ease of assembling the journal bearing can be maintained.

Further, since the outer liner 62 is provided in the lower bearing housing 30b to which the load of the journal j is loaded, the load load can be easily adjusted, and the connecting portion between the outer liner 33 and the bearing base 20 can be deformed and elastic. Since the flexible O-ring 76 is attached, the load load can be adjusted more easily.
Lubricating oil is supplied to the oil supply nozzle 50 from the oil supply hole 60 provided in the bearing stand 20 through the annular oil guide groove 66 and the oil supply hole 68 and the oil supply hole 56 formed in the oil supply nozzle 50. Therefore, the lubricating oil can be supplied to the oil supply nozzle 50 with a simple configuration without reducing the strength of the bearing housing 30.

  In addition, although the O-ring was used for the connection part of the outer liner 33 and the bearing stand 20, not only an O-ring but another elastic body, for example, a bellows structure etc., may be used. Thus, by using an elastic body, it becomes easy to adjust the load of the bearing housing 30 loaded on the bearing stand 20 via the outer liner 33.

  According to the present invention, it is possible to form a high oil film pressure of lubricating oil on the upper pad bearing surface of a pad-type journal bearing that supports a rotating shaft by low-cost and simple means. It is suitable to be applied to a machine.

FIG. 4 is a front sectional view (CC sectional view in FIG. 2) according to an embodiment of the rotating structure of the present invention. It is side sectional drawing (BB sectional drawing in FIG. 3) of the said embodiment. It is a rear view (view A in FIG. 2) of the embodiment. FIG. 2 is a partially enlarged view of the vicinity of a spherical pivot 36 in FIG. 1. It is a perspective view of the oil supply nozzle 50 of the embodiment. FIG. 2 is a partially enlarged view of the vicinity of an oil supply hole 60 in FIG. 1. It is sectional drawing which follows the DD line | wire in FIG. It is a diagram which shows the mechanical loss of the journal bearing of an oil bath lubrication system. It is explanatory drawing which shows the oil film pressure formation of the journal bearing by a wedge film effect.

DESCRIPTION OF SYMBOLS 10 Journal bearing 20 Bearing stand 30 Bearing housing 30a Upper bearing housing 30b Lower bearing housing 33,62 Outer liner 35 Side plate 36 Spherical pivot 38 Measurement hole 40a-d Tilting pad 44 Adjustment liner 46 Inclined surface 46a Root part 48 Bearing surface 50 Lubrication nozzle 52 Main casing 54 Arms 56, 60, 62a, 68 Lubrication hole 58 Nozzle port 66 Oil guide groove 76 O-ring 80 Coil spring 86 Shim plate for height adjustment 90 Screw hole 92 Bolt through hole 94 Hexagon socket head cap screw s1 to s4 Gap

Claims (4)

Rotation provided with a journal bearing having a plurality of pads which are swingably disposed in an annular bearing housing and which support the journal in a self-aligning manner, and which supplies lubricating oil between the pads and the journal. In the structure,
The center region of the pad is supported on a spherical pivot provided on the inner surface of the bearing housing so as to be swingable in the axial direction and the circumferential direction of the journal,
In the bearing housing supporting the upper pads arranged in an upper position where the own weight of the journal is not loaded, the measurement hole penetrating from the back of the spherical pivot on the outer surface of the bearing housing is provided, the spherical pivot back from the opening of the measurement hole A rotary structure having a journal bearing, characterized in that the gap between the journal and the upper pad is adjusted based on the measured depth value . In the bearing housing, a spring member is provided between the inner surface of the bearing housing and the back surface of the upper pad at a downstream portion of the upper pad in the journal rotation direction, and the spring member biases the downstream portion of the upper pad toward the journal side. Give the elastic force to
2. A rotating structure having a journal bearing according to claim 1, wherein a narrowing gap is formed between the upper pad and the journal toward the downstream side in the journal rotating direction by the elastic force of the spring member. body. 3. A lift means that can lift the upstream portion of the upper pad in the journal rotation direction is provided, and the clearance between the upper pad and the upstream portion of the journal in the rotation direction can be adjusted by the lift means. A rotating structure comprising the journal bearing described in 1. The lift means is inserted into a through hole formed in a radial direction in the bearing housing and a screw hole formed in the pad and opened in a position continuous with the through hole and in the same direction. And a bolt that is screwed into the screw hole at the same time, and the gap between the bearing housing and the pad can be adjusted by adjusting a screwing length of the bolt into the screw hole. A rotating structure including the journal bearing according to Item 3 .

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