JP6403594B2 - Journal bearing and rotating machine - Google Patents

Description

  The present disclosure relates to journal bearings and rotating machines.

Journal bearings used in rotating machines such as steam turbines, gas turbines, blowers, and compressors are widely known.
For example, Patent Document 1 discloses a journal bearing including a carrier ring, a guide metal, a first bearing pad, a second bearing pad, and a plurality of oiling nozzles. The oil supply nozzle supplies the supplied lubricating oil between the outer peripheral surface of the rotor shaft and the inner peripheral surface of the bearing pad, and includes a first oil supply nozzle disposed at one end of the guide metal, A second oil supply nozzle disposed at both ends of the bearing pad; and a fourth oil supply nozzle disposed at one end of the second bearing pad. The same amount of lubricating oil is supplied from each of the oil supply nozzles (the first oil supply nozzle, the second oil supply nozzle, the third oil supply nozzle, and the fourth oil supply nozzle).

Japanese Patent No. 4764486

  The present inventors have found that in the journal bearing disclosed in Patent Document 1, it may be difficult to form an oil film having a sufficient thickness on the first bearing pad. In particular, when the surface pressure of the rotor shaft relative to the first bearing pad and the second bearing pad is low, or when the rotor shaft rotates in a low rotation region, it is difficult to sufficiently secure the oil film thickness of the first bearing pad. It became clear.

  In view of the above circumstances, at least one embodiment of the present invention aims to provide a journal bearing and a rotary machine that can sufficiently secure the oil film thickness in a bearing pad located on the upstream side in the rotation direction of the rotor shaft. To do.

(1) A journal bearing according to at least one embodiment of the present invention includes:
A carrier ring formed in a cylindrical shape;
A first bearing pad provided on the inner peripheral side of the lower half region of the carrier ring and configured to support the rotor shaft from below;
A second bearing pad provided on the inner peripheral side of the lower half region of the carrier ring on the downstream side in the rotational direction of the rotor shaft with respect to the first bearing pad and configured to support the rotor shaft from below; ,
A guide metal provided on the inner peripheral side of the upper half region of the carrier ring, and covering the upper region of the outer peripheral surface of the rotor shaft;
A first oiling unit installed immediately before the upstream side of the first bearing pad;
A second oil supply unit installed at a circumferential position between the first bearing pad and the second bearing pad;
A pair of side plates installed along the outer periphery of the rotor shaft at one end and the other end in the axial direction of the carrier ring;
With
Between the inner peripheral surface of each side plate and the outer peripheral surface of the rotor shaft, there is a gap for communicating the bearing inner space surrounded by the pair of side plates and the outside,
The amount of lubricating oil discharged from the first oil supply unit is set larger than the amount of lubricating oil discharged from the second oil supply unit.

  As a result of intensive studies by the present inventors, for example, the cause of the problem of insufficient oil film thickness of the first bearing pad in the conventional journal bearing described in Patent Document 1 is the lubricant that is carried over to the first bearing pad. It was found that the air was mixed. That is, the conventional journal bearing has a gap for communicating the bearing inner space surrounded by the pair of side plates and the outside between the inner peripheral surface of each side plate and the outer peripheral surface of the rotor shaft, In the region from the second bearing pad to the first bearing pad in the rotation direction of the rotor shaft, the air sucked from the gap is mixed into the lubricating oil. For this reason, the lubricating oil carried over to the first bearing pad contains a large amount of air, and the actual amount of lubricating oil is small (for example, 10% of lubricating oil with respect to 90% of air). Therefore, even if the amount of discharged oil is the same between the first oil supply unit immediately before the upstream side of the first bearing pad and the second oil supply unit immediately before the upstream side of the second bearing pad, compared to the second bearing pad. The first bearing pad tends to be short of lubricating oil. In particular, when the surface pressure of the rotor shaft with respect to the first bearing pad and the second bearing pad is low, or when the rotor shaft rotates in a low rotation region, the lubricating oil carried over to the first bearing pad is small. The lack of lubricating oil in the first bearing pad is significant. When the lubricating oil supplied to the first bearing pad is insufficient, the first bearing pad does not get wet from the inlet, and therefore the oil film pressure generation region is narrowed, and the oil film of the first bearing pad becomes thin. As a result, when the surface pressure of the rotor shaft relative to the first bearing pad and the second bearing pad is low or the rotor shaft rotates in the low rotation region, the axis of the rotor shaft deviates from the vertical line and the journal. The isotropy of the bearing may be impaired.

  In this regard, according to the configuration of (1) above, even if air is sucked into the lubricating oil in the region from the second bearing pad to the first bearing pad on the downstream side in the rotation direction of the rotor shaft, Sufficient lubricating oil is supplied to the bearing pads. Thereby, even when the surface pressure of the rotor shaft with respect to the first bearing pad and the second bearing pad is low or the rotor shaft rotates in a low rotation region, the oil film thickness at the first bearing pad can be sufficiently secured. .

(2) In some embodiments, in the configuration of (1) above,
The total oil discharge hole area of the first oil supply unit is larger than the total oil discharge hole area of the second oil supply unit.
According to the configuration of (2) above, the amount of lubricating oil supplied from the first oil supply unit to the first bearing pad is larger than the amount of lubricating oil supplied from the second oil supply unit to the second bearing pad. Easy to set.

(3) In some embodiments, in the configuration of (2) above,
The number of oil discharge holes of the first oil supply unit is larger than the number of oil discharge holes of the second oil supply unit.
According to the configuration of (3) above, by providing a difference in the number of oil discharge holes between the first oil supply unit and the second oil supply unit, the total area of the oil discharge holes of the first oil supply unit is set to that of the second oil supply unit. The total area of the oil discharge holes can be made larger.

(4) In some embodiments, in the configuration of (2) or (3) above,
The size of the oil discharge hole of the first oil supply unit is larger than the size of the oil discharge hole of the second oil supply unit.
According to the configuration of (4) above, by providing a difference in the size of the oil discharge holes between the first oil supply unit and the second oil supply unit, the total oil discharge hole area of the first oil supply unit is set to the second oil supply. The total oil discharge hole area of the unit can be made larger.

(5) In some embodiments, in any one of the above configurations (1) to (4),
The carrier ring has a manifold that communicates with the first oil supply unit and the second oil supply unit inside the carrier ring.
According to the configuration of (5), the lubricating oil supplied to the manifold can be distributed to the first oil supply unit and the second oil supply unit.

(6) In some embodiments, in the configuration of (5) above,
The carrier ring includes a lower half portion constituting a lower half region and an upper half portion constituting an upper half region, and the manifold penetrates only one joining surface of the upper half portion and the lower half portion. To do.
According to the configuration of (6) above, it is only necessary to seal one joint surface through which the manifold penetrates, and the cost can be reduced.

(7) In some embodiments, in any one of the configurations (1) to (6) above,
The internal pressure of the first oil supply unit is greater than the internal pressure of the second oil supply unit.
According to the configuration of (7) above, by providing a difference in internal pressure between the first oil supply unit and the second oil supply unit, the amount of lubricating oil supplied from the first oil supply unit to the first bearing pad can be reduced. It can be set to be larger than the amount of lubricating oil supplied from the second oil supply unit to the second bearing pad.

(8) In some embodiments, in the configuration of (7) above,
A second oil supply source that supplies lubricating oil to the second oil supply unit; and a first oil supply source that supplies lubricating oil to the first oil supply unit at a pressure higher than that of the second oil supply source.
According to the configuration of (8) above, the amount of lubricating oil supplied from the first oil supply unit to the first bearing pad is larger than the amount of lubricating oil supplied from the second oil supply unit to the second bearing pad. Can be set.

(9) A rotating machine according to at least one embodiment of the present invention includes:
The rotor shaft is supported by the journal bearing described in any one of (1) to (8) above.
With configuration (9) above, it is possible to sufficiently ensure the oil film thickness at the bearing pad located on the upstream side in the rotational direction of the rotor shaft.

  According to at least one embodiment of the present invention, it is possible to sufficiently ensure the oil film thickness in the bearing pad located on the upstream side in the rotation direction of the rotor shaft.

It is a figure which shows the cross section of the journal bearing which concerns on one Embodiment of this invention schematically, Comprising: It is a figure which shows the state supported by the housing. It is sectional drawing which follows the II-II line of the journal bearing supported by the housing shown in FIG. It is sectional drawing which follows the III-III line of the journal bearing supported by the housing shown in FIG. It is a figure which shows schematically the nozzle which comprises a 1st oil supply unit. It is an expanded view which shows schematically the carrier ring, side plate, bearing pad, oil supply unit, and side plate which concern on one Embodiment. It is an expanded view which shows schematically the carrier ring, side plate, bearing pad, oil supply unit, and side plate which concern on one Embodiment. It is a cross-sectional view of a journal bearing according to an embodiment. It is a cross-sectional view of a journal bearing according to an embodiment.

Hereinafter, some embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described in the embodiments or shown in the drawings are not intended to limit the scope of the present invention, but are merely illustrative examples. Absent.
For example, expressions expressing relative or absolute arrangements such as “in a certain direction”, “along a certain direction”, “parallel”, “orthogonal”, “center”, “concentric” or “coaxial” are strictly In addition to such an arrangement, it is also possible to represent a state of relative displacement with an angle or a distance such that tolerance or the same function can be obtained.
In addition, for example, expressions representing shapes such as quadrangular shapes and cylindrical shapes not only represent shapes such as quadrangular shapes and cylindrical shapes in a strict geometric sense, but also within the range where the same effect can be obtained. A shape including a chamfered portion or the like is also expressed.
On the other hand, the expressions “comprising”, “comprising”, “comprising”, “including”, or “having” one constituent element are not exclusive expressions for excluding the existence of the other constituent elements.

  FIG. 1 is a view schematically showing a cross section of a journal bearing 1 according to an embodiment of the present invention, and is a view showing a state supported by a housing H. FIG. 2 is a cross-sectional view taken along line II-II of the journal bearing 1 supported by the housing H shown in FIG. 1, and FIG. 3 is a cross-sectional view of the journal bearing 1 supported by the housing H shown in FIG. It is sectional drawing which follows the -III line. FIG. 1 is a cross-sectional view taken along line II of the journal bearing 1 supported by the housing H shown in FIG.

  In some embodiments, as shown in FIG. 1 to FIG. 3, the journal bearing 1 is a mechanical element for rotatably supporting the rotor shaft 11, and is supported by a housing H, and includes a steam turbine, a gas turbine, It is attached to a rotating machine such as a blower or a compressor. As shown in FIGS. 2 and 3, the housing H has a pedestal part H1 constituting the lower half part and a cover H2 constituting the upper half part, and the housing H is provided between the pedestal part H1 and the cover H2. In a state where the journal bearing 1 according to the embodiment is sandwiched, the cover H2 is fastened to the pedestal portion H1 with a bolt H3. Thereby, the journal bearing 1 is supported by the housing H, and the rotor shaft 11 rotatably supported by the journal bearing 1 is also rotatably supported by the housing H.

  In some embodiments, as shown in FIGS. 1 to 3, the journal bearing 1 includes a carrier ring 2, a first bearing pad 31, a second bearing pad 32, a guide metal 33, a first oil supply unit 4, a second An oil supply unit 5 and a pair of side plates 7 are provided.

  As shown in FIGS. 1 and 2, the carrier ring 2 is disposed inside the housing H and has a cylindrical space and can surround a part of the rotor shaft 11, that is, the journal 12. The carrier ring 2 has, for example, a cylindrical shape with a rectangular cross section.

  The first bearing pad 31 is provided on the inner peripheral side of the lower half region of the carrier ring 2 and is configured to support the rotor shaft 11 from below. The first bearing pad 31 has a sector shape when viewed along the axial direction of the carrier ring 2, and has a curved inner peripheral surface 31 a and outer peripheral surface 31 b. The inner peripheral surface 31 a of the first bearing pad 31 is formed of a bearing alloy, for example, white metal, and is disposed to face a part of the rotor shaft 11, that is, the outer peripheral surface 12 a of the journal 12.

  In some embodiments, a tilting unit (not shown) is provided between the first bearing pad 31 and the carrier ring 2, and the first bearing pad 31 is supported to be tiltable.

  The second bearing pad 32 is provided on the inner peripheral side of the lower half region of the carrier ring 2 on the downstream side in the rotation direction of the rotor shaft 11 with respect to the first bearing pad 31, and similarly to the first bearing pad 31, the rotor shaft 11. Is supported from below. Similar to the first bearing pad 31, the second bearing pad 32 has a sector shape when viewed along the axial direction of the carrier ring 2, and has a curved inner peripheral surface 32a and outer peripheral surface 32b. Yes. Similar to the first bearing pad 31, the inner peripheral surface 32 a of the second bearing pad 32 is formed of a bearing alloy, for example, white metal, and is disposed to face the outer peripheral surface 12 a of the journal 12.

  In some embodiments, a tilting unit (not shown) is provided between the second bearing pad 32 and the carrier ring 2, as in the case between the second bearing pad 32 and the carrier ring 2. The two bearing pads 32 are supported to be tiltable.

In one embodiment, as shown in FIG. 2, the guide metal 33 is provided on the inner peripheral side of the upper half region of the carrier ring 2, and is fixed to the carrier ring 2 with a bolt or the like (not shown). In another embodiment, the guide metal 33 is formed integrally with the carrier ring 2.
In the exemplary embodiment shown in FIG. 2, the guide metal 33 has a fan shape when viewed along the axial direction of the carrier ring 2 and covers the upper region of the outer peripheral surface of the rotor shaft 11. . The guide metal 33 has a bearing surface 33 a on the inner side in the radial direction of the carrier ring 2. The bearing surface 33a is curved along the upper region of the outer peripheral surface 12a of the journal 12, and is opposed to the upper region of the outer peripheral surface 12a of the journal 12 with a bearing gap.

As shown in FIG. 2, in some embodiments, the journal bearing 1 includes a plurality of oil supply units (4, 5, 6) for supplying lubricating oil toward the rotor shaft 11.
The plurality of oil supply units (4, 5, 6) are spaced apart from each other in the circumferential direction, and can each supply lubricating oil toward the rotor shaft 11. For example, a manifold 24 is formed in the carrier ring 2, and lubricating oil is supplied to the plurality of oil supply units (4, 5, 6) through the manifold 24.

  The first oil supply unit 4 is for supplying lubricating oil toward a part of the rotor shaft 11, that is, the journal 12, and is provided on the upstream side of the first bearing pad 31 in the rotational direction of the rotor shaft 11. It is arranged immediately before 31. The first oil supply unit 4 includes a plurality of nozzles 41, 42, for example, two nozzles 41, 42. The plurality of nozzles 41 and 42 of the first oil supply unit 4 are fixed with an interval immediately before the upstream side of the first bearing pad 31.

FIG. 4 is a diagram schematically showing the nozzles 41 and 42 constituting the first oil supply unit 4.
As shown in FIG. 4, the nozzles 41 and 42 of the first oil supply unit 4 each have a base portion 43 and a branch portion 44. The base 43 has a cylindrical shape with a closed end, is disposed along the radial direction of the carrier ring 2, and is fixed to the carrier ring 2 so as to communicate with the manifold 24. The branch portion 44 has a cylindrical shape whose tip is narrower than the base portion 43, is arranged along the axial direction of the carrier ring 2, and is provided on both sides of the base portion 43 so as to communicate with the internal space of the base portion 43. It is fixed. Further, the branch portion 44 is provided with a plurality of oil discharge holes 45 so as to face the axis of the carrier ring 2.

  As shown in FIG. 2, the second oil supply unit 5 is for supplying lubricating oil toward a part of the rotor shaft 11, that is, the journal 12, like the first oil supply unit 4. It is arranged at a circumferential position between 31 and the second bearing pad 32. Similar to the first oil supply unit 4, the second oil supply unit 5 includes a plurality of nozzles 51 and 52, for example, two nozzles 51 and 52. The plurality of nozzles 51 and 52 of the second oil supply unit 5 are arranged at intervals in the circumferential position between the first bearing pad 31 and the second bearing pad 32. Since the nozzles 51 and 52 have the same configuration as the nozzles 41 and 42 constituting the first oil supply unit 4, here, the corresponding base 53, branch 54 and oil discharge hole 55 are denoted by the reference numerals in FIG. A description thereof will be omitted.

  Similar to the first oil supply unit 4 and the second oil supply unit 5, the third oil supply unit 6 is for supplying lubricating oil toward the rotor shaft 11, that is, the journal 12, and the rotor shaft of the second bearing pad 32. 11 is disposed immediately downstream of the second bearing pad 32 on the downstream side in the rotational direction. The third oil supply unit 6 may include a plurality of nozzles, but in the exemplary embodiment shown in FIG. Since the nozzle 61 has the same configuration as the nozzle 41 constituting the first oil supply unit 4, the corresponding base 63, branch 64, and oil discharge hole 65 are described here with reference to FIG. 4. Is omitted.

  The pair of side plates 7 are disposed along the outer periphery of the rotor shaft 11 at one end and the other end in the axial direction of the carrier ring 2, and define both ends of the internal space of the journal bearing 1 in the axial direction of the carrier ring 2. ing. The pair of side plates 7 are respectively fixed to the carrier ring 2 with bolts 71.

As shown in FIG. 1, in some embodiments, the lubricating oil supply method in the journal bearing 1 is a so-called direct lubrication method. That is, the journal bearing 1 includes a bearing inner space surrounded by a pair of side plates 7 between the inner peripheral surface of each side plate 7 and a part of the rotor shaft 11, that is, the outer peripheral surface 12 a of the journal 12. There is a gap C for communicating with each other. For this reason, the internal space of the journal bearing 1 is not completely filled with the lubricating oil, and at least a part of the internal space of the journal bearing 1 is occupied by air entering from the outside. The pressure of the lubricating oil present inside the journal bearing 1 is equivalent to the atmospheric pressure.
In this respect, the above-described direct lubrication type journal bearing 1 is different from an oil bath lubrication type journal bearing in which the bearing internal space is filled with lubricating oil. In an oil bath lubrication type journal bearing, a sealing member is provided between the side plate and the outer peripheral surface of the journal to prevent leakage of the lubricating oil from the bearing inner space to the outside so that the bearing inner space is filled with the lubricating oil. It has become. For this reason, the lubricating oil present in the internal space of the oil bath lubrication type journal bearing is at a pressure higher than the atmospheric pressure.

Here, in the journal bearing 1 of the direct lubrication system, there is a tendency that the oil film thickness in the bearing pad (first bearing pad 31) located on the upstream side in the rotation direction of the rotor shaft 11 is insufficient. This is considered to be caused by air mixing in the lubricating oil carried over by the first bearing pad 31.
That is, in the journal bearing 1 of the direct lubrication system, the bearing inner space surrounded by the pair of side plates 7 is communicated with the outside between the inner peripheral surface of each side plate 7, 7 and the outer peripheral surface of the rotor shaft 11. In the region from the second bearing pad 32 to the first bearing pad 31 in the rotational direction of the rotor shaft 11, air sucked from the gap C is mixed into the lubricating oil. For this reason, the lubricating oil carried over to the first bearing pad 31 contains a large amount of air, and the amount of substantial lubricating oil is small (for example, 10% of lubricating oil with respect to 90% of air). Therefore, even if the discharge oil amount of the first oil supply unit 4 immediately before the upstream side of the first bearing pad 31 and the second oil supply unit 5 immediately before the upstream side of the second bearing pad 32 are the same, the second bearing Compared to the pad 32, the first bearing pad 31 tends to be insufficient in lubricating oil. In particular, when the surface pressure of the rotor shaft 11 with respect to the first bearing pad 31 and the second bearing pad 32 is low, or when the rotor shaft 11 rotates in a low rotation region, the first bearing pad 31 carries over. Since there is little lubricating oil, the lubricating oil shortage in the 1st bearing pad 31 is remarkable. When the lubricating oil supplied to the first bearing pad 31 is insufficient, the first bearing pad 31 does not get wet from the inlet, so that the oil film pressure generation region is narrowed, and the oil film of the first bearing pad 31 becomes thin. Thereby, when the surface pressure of the rotor shaft 11 with respect to the first bearing pad 31 and the second bearing pad 32 is low, or when the rotor shaft 11 rotates in a low rotation region, the axial locus of the rotor shaft 11 is vertical. There is a possibility that the isotropic property of the journal bearing 1 is lost due to deviation from the line.

Therefore, in some embodiments, the amount of lubricating oil discharged from the first oil supply unit 4 is set to be larger than the amount of lubricating oil discharged from the second oil supply unit 5.
In this case, even if air is sucked into the lubricating oil in the region from the second bearing pad 32 to the first bearing pad 31 downstream in the rotational direction of the rotor shaft 11, the lubricating oil is supplied from the first oil supply unit 4 to the first bearing pad 31. Is fully supplied. Thereby, even when the surface pressure of the rotor shaft 11 with respect to the first bearing pad 31 and the second bearing pad 32 is low or the rotor shaft 11 rotates in a low rotation region, the axial locus of the rotor shaft 11 is vertical. Since it is located on the line, the isotropic property of the journal bearing 1 can be maintained.

5 and 6 are development views schematically showing the carrier ring 2, the side plate 7, the bearing pads 31, 32, the oil supply units 4, 5, 6 and the side plate 7. FIG.
As shown in FIGS. 5 and 6, in some embodiments, the total oil discharge hole area of the first oil supply unit 4 is larger than the total oil discharge hole area of the second oil supply unit 5. For example, the total oil discharge hole area of the first oil supply unit 4 is 3, whereas the total oil discharge hole area of the second oil supply unit 5 is 3. In this case, when the first oil supply unit 4 and the second oil supply unit 5 are configured by two nozzles 41, 42, 51, 52, the oil discharge hole area is determined by the two nozzles 41, 42 configuring the first oil supply unit 4. The oil discharge hole 45 is formed so that the oil discharge hole 45 becomes 3, and the two nozzles 51 and 52 constituting the second oil supply unit 5 form the oil discharge hole 55 so that the oil discharge hole area becomes 3.

  Further, the total oil discharge hole area of the third oil supply unit 6 is smaller than the total oil discharge hole area of the second oil supply unit 5, and the total oil discharge hole area of the second oil supply unit 5 is 3 with respect to the third oil supply unit 6. The total oil discharge hole area is 2. In this case, when the second oil supply unit 5 is constituted by two nozzles 51 and 52 and the third oil supply unit 6 is constituted by one nozzle 61, the two nozzles 51 and 52 constituting the second oil supply unit 5 are oiled. The oil discharge hole 55 is formed so that the total area of the discharge hole becomes 3, and the oil discharge hole 65 is formed so that the total area of the oil discharge hole becomes 2 by one nozzle 61 constituting the third oil supply unit 6. .

  According to this configuration, the amount of lubricating oil discharged from the first oil supply unit 4 can be set more easily than the amount of lubricating oil discharged from the second oil supply unit 5. Accordingly, the amount of lubricating oil supplied from the first oil supply unit 4 to the first bearing pad 31 can be set larger than the amount of lubricating oil supplied from the second oil supply unit 5 to the second bearing pad. In the example described above, the amount of lubricating oil discharged from the second oil supply unit 5 can be set to 3 while the amount of lubricating oil discharged from the first oil supply unit 4 is 5. Similarly, the lubricating oil discharged from the third oil supply unit 6 can be set to 3 while the lubricating oil discharged from the second oil supply unit 5 is 3. Thus, when the total amount of lubricating oil discharged from the first oil supply unit 4, the second oil supply unit 5, and the third oil supply unit 6 is 5, the first oil supply units 4 to 2.5, the second oil supply unit 5 1 to 1.5, and the third oil supply unit 6 discharges 1 lubricating oil.

  As shown in FIG. 5, in some embodiments, the number of oil discharge holes 45 of the first oil supply unit 4 is larger than the number of oil discharge holes 45 of the second oil supply unit 5. For example, when the size of the oil discharge hole 45 of the first oil supply unit 4 and the size of the oil discharge hole 55 of the second oil supply unit 5 are equal, the number of oil discharge holes 45 of the first oil supply unit 4 is 5 Thus, the number of oil discharge holes 55 of the second oil supply unit 5 is three. In this case, when the first oil supply unit 4 and the second oil supply unit 5 are configured by two nozzles 41, 42, 51, 52, the oil discharge holes 45 are formed by the two nozzles 41, 42 configuring the first oil supply unit 4. The oil discharge holes 45 are formed so that the number of oil discharge holes 45 is five, and the oil discharge holes 55 are formed so that the number of oil discharge holes 55 is three by the two nozzles 51, 52 constituting the second oil supply unit 5. The

  Further, when the size of the oil discharge hole 45 of the second oil supply unit 5 and the size of the oil discharge hole 55 of the third oil supply unit 6 are made equal, the number of oil discharge holes 65 of the third oil supply unit 6 is the second oil supply number. The number of oil discharge holes 55 of the third oil supply unit 6 is two while the number of oil discharge holes 55 of the second oil supply unit 5 is three and the number of oil discharge holes 65 of the third oil supply unit 5 is two. In this case, when the second oil supply unit 5 is constituted by two nozzles 51 and 52 and the third oil supply unit 6 is constituted by one nozzle 61, the two nozzles 51 and 52 constituting the second oil supply unit 5 are oiled. The oil discharge holes 55 are formed so that the number of the discharge holes 55 is three, and the oil discharge holes are formed so that the number of the oil discharge holes 65 is two by one nozzle 61 constituting the third oil supply unit 6. The Thereby, in the second oil supply unit 5 and the third oil supply unit 6, the number of oil discharge holes 55 and 65 per nozzle is larger in the third oil supply unit 6 than in the second oil supply unit 5. In terms of the total number of nozzles, the second oil supply unit 5 is more numerous than the third oil supply unit 6.

  According to this configuration, by providing a difference in the number of oil projecting holes between the first oil supply unit 4 and the second oil supply unit 5, the total oil discharge hole area of the first oil supply unit 4 can be reduced. The total area of the oil discharge holes can be made larger. In the example described above, the total oil discharge hole area of the second oil supply unit 5 can be set to 3 with respect to the total oil discharge hole area of the first oil supply unit 4. Similarly, the total oil discharge hole area of the second oil supply unit 5 can be set to 3, while the total oil discharge hole area of the third oil supply unit 6 can be set to two.

  As shown in FIG. 6, in some embodiments, the size of the oil discharge hole 45 of the first oil supply unit 4 is larger than the size of the oil discharge hole 55 of the second oil supply unit 5. For example, when the number of oil discharge holes 45 of the first oil supply unit 4 and the number of oil discharge holes 55 of the second oil supply unit 5 are equal, the size (opening area) of the oil discharge holes 45 of the first oil supply unit 4 Is 5 and the size (opening area) of the oil discharge hole 55 of the second oil supply unit 5 is 3.

  According to this configuration, by providing a difference in the size of the oil discharge holes between the first oil supply unit 4 and the second oil supply unit 5, the total oil discharge hole area of the first oil supply unit 4 is set to the second oil supply unit. The total oil discharge hole area of 5 can be made larger. In the example described above, the total oil discharge hole area of the second oil supply unit 5 can be set to 3 with respect to the total oil discharge hole area of the first oil supply unit 4. Similarly, the total oil discharge hole area of the second oil supply unit 5 can be set to 3, while the total oil discharge hole area of the third oil supply unit 6 can be set to two.

  In some embodiments, the number of oil discharge holes 45 in the first oil supply unit 4 is larger than the number of oil discharge holes 55 in the second oil supply unit 5, and the oil discharge holes 45 in the first oil supply unit 4. Is larger than the size of the oil discharge hole 55 of the second oil supply unit 5.

  According to this configuration, the total oil discharge hole area of the first oil supply unit 4 can be made larger than the total oil discharge hole area of the second oil supply unit 5. For example, the total oil discharge hole area of the second oil supply unit 5 can be set to 3 with respect to the total oil discharge hole area of the first oil supply unit 4. Similarly, the total oil discharge hole area of the second oil supply unit 5 can be set to 3, while the total oil discharge hole area of the third oil supply unit 6 can be set to two.

FIG. 7 is a cross-sectional view of the journal bearing 1 according to an embodiment.
As shown in FIG. 7, in some embodiments, the carrier ring 2 has a manifold 24 that communicates with the first oil supply unit 4 and the second oil supply unit 5 therein.
According to this configuration, the lubricating oil supplied to the manifold 24 can be distributed to the first oil supply unit 4 and the second oil supply unit 5.

As shown in FIG. 7, in some embodiments, the carrier ring 2 includes a lower half 25 that constitutes the lower half region and an upper half 26 that constitutes the upper half region. Only one joint surface 27 of the half part 25 and the upper half part 26 is penetrated.
That is, the manifold 24 is provided in an arc shape along the inner periphery of the carrier ring 2, and one end of the manifold 24 is located upstream of the central portion of the lower half 25 constituting the lower half region in the rotational direction of the rotor shaft 11. It passes through the joint surface 27 and extends to the upper half 26 constituting the upper half region. On the other hand, the other end portion of the manifold 24 extends from the central portion of the lower half portion 25 to the downstream side in the rotation direction of the rotor shaft 11 and stops before the joint surface 28 on the downstream side in the rotation direction of the rotor shaft 11.

  According to this configuration, it is only necessary to seal one joint surface 27 through which the manifold 24 passes, and the cost can be reduced as compared to the case where both the joint surfaces 27 and 28 are sealed.

FIG. 8 is a cross-sectional view of the journal bearing 1 according to an embodiment.
As shown in FIG. 8, in some embodiments, the internal pressure of the first oil supply unit 4 is greater than the internal pressure of the second oil supply unit 5. For example, the number of oil discharge holes 45 of the first oil supply unit 4 is equal to the number of oil discharge holes 45 of the second oil supply unit 5, and the size of the oil discharge holes 45 of the first oil supply unit 4 and the second oil supply unit 45 are the same. When the sizes of the five oil discharge holes 45 are equal, the internal pressure of the second oil supply unit 5 is 3 with respect to the internal pressure of the first oil supply unit 4.

  According to this configuration, by providing a difference in internal pressure between the first oil supply unit 4 and the second oil supply unit 5, the amount of lubricating oil supplied from the first oil supply unit 4 to the first bearing pad 31 can be reduced. The amount of lubricating oil supplied from the second oil supply unit 5 to the second bearing pad 32 can be set larger. In the example described above, the amount of lubricating oil discharged from the second oil supply unit 5 can be set to 3 while the amount of lubricating oil discharged from the first oil supply unit 4 is 5.

  As shown in FIG. 8, in some embodiments, the second oil supply source 82 supplies lubricating oil to the second oil supply unit 5, and the first oil supply unit 4 is supplied with lubricating oil at a pressure higher than that of the second oil supply source. And a first oil supply source 81 to be supplied. For example, the number of oil discharge holes 45 of the first oil supply unit 4 and the number of oil discharge holes 55 of the second oil supply unit 5 are equal, and the size of the oil discharge holes 45 of the first oil supply unit 4 and the second oil supply unit 55 When the sizes of the five oil discharge holes 55 are equal, the pressure of the first oil supply source 81 is 5 and the pressure of the second oil supply source 82 is 3.

  According to this configuration, the amount of lubricating oil supplied from the first oil supply unit 4 to the first bearing pad 31 is larger than the amount of lubricating oil supplied from the second oil supply unit 5 to the second bearing pad 32. Can be set. In the example described above, the amount of lubricating oil discharged from the second oil supply unit 5 can be set to 3 while the amount of lubricating oil discharged from the first oil supply unit 4 is 5.

  As shown in FIG. 8, in some embodiments, the carrier ring 2 includes a lower half 25 that constitutes the lower half region and an upper half 26 that constitutes the upper half region. Only one joint surface 27 of the lower half 25 and the upper half 26 penetrates. That is, one manifold 24 </ b> A is provided in an arc shape along the inner periphery of the carrier ring 2, and the joint surface 27 on the upstream side in the rotational direction of the rotor shaft 11 from the upstream portion in the rotational direction of the rotor shaft 11 in the lower half 25. The street extends to the upper half 26. On the other hand, the other manifold 24 </ b> B is provided at the downstream portion of the lower half portion 25 in the rotational direction of the rotor shaft 11, and stops before the other joining surface 28 of the lower half portion 25 and the upper half portion 26. That is, the other manifold 24 </ b> B is provided in an arc shape along the inner periphery of the carrier ring 2, and stops before the other joint surface 28 of the lower half portion 25 and the upper half portion 26.

  According to this configuration, it is only necessary to seal one joint surface 27 through which one manifold 24A passes, and the cost can be reduced as compared with the case where both joint surfaces 27 and 28 are sealed.

  The present invention is not limited to the above-described embodiments, and includes forms obtained by modifying the above-described embodiments and forms obtained by appropriately combining these forms.

1 journal bearing 11 rotor shaft 12 journal 12a outer peripheral surface 2 carrier ring 24 manifold 24A, 24B manifold 25 lower half 26 upper half 27, 28 joint surface 31 first bearing pad 31a inner peripheral surface 31b outer peripheral surface 32 second bearing pad 32a Inner peripheral surface 32b Outer peripheral surface 33 Guide metal 33a Bearing surface 4 First oil supply unit 41 Nozzle 42 Nozzle 43 Base 44 Branch part 45 Oil discharge hole 5 Second oil supply unit 51, 52 Nozzle 53 Base part 54 Branch part 55 Oil discharge hole 6 Third oil supply unit 61 Nozzle 63 Base 64 Branch 65 Oil discharge hole 7 Side plate 71 Bolt 81 First oil source 82 Second oil source C Clearance H Housing H1 Base part H2 Cover H3 Bolt

Claims (9)

A carrier ring formed in a cylindrical shape;
A first bearing pad provided on the inner peripheral side of the lower half region of the carrier ring and configured to support the rotor shaft from below;
A second bearing pad provided on the inner peripheral side of the lower half region of the carrier ring on the downstream side in the rotational direction of the rotor shaft with respect to the first bearing pad and configured to support the rotor shaft from below; ,
A guide metal provided on the inner peripheral side of the upper half region of the carrier ring, and covering the upper region of the outer peripheral surface of the rotor shaft;
A first oiling unit installed immediately before the upstream side of the first bearing pad;
A second oil supply unit installed at a circumferential position between the first bearing pad and the second bearing pad;
A pair of side plates installed along the outer periphery of the rotor shaft at one end and the other end in the axial direction of the carrier ring;
With
Between the inner peripheral surface of each side plate and the outer peripheral surface of the rotor shaft, there is a gap for communicating the bearing inner space surrounded by the pair of side plates and the outside,
The journal bearing characterized in that the amount of lubricating oil discharged from the first oil supply unit is set to be larger than the amount of lubricating oil discharged from the second oil supply unit.   The journal bearing according to claim 1, wherein a total oil discharge hole area of the first oil supply unit is larger than a total oil discharge hole area of the second oil supply unit.   The journal bearing according to claim 2, wherein the number of oil discharge holes of the first oil supply unit is larger than the number of oil discharge holes of the second oil supply unit.   The journal bearing according to claim 2 or 3, wherein a size of the oil discharge hole of the first oil supply unit is larger than a size of the oil discharge hole of the second oil supply unit.   5. The journal bearing according to claim 1, wherein the carrier ring includes a manifold that communicates with the first oil supply unit and the second oil supply unit inside the carrier ring.   The carrier ring includes a lower half portion constituting a lower half region and an upper half portion constituting an upper half region, and the manifold penetrates only one joining surface of the upper half portion and the lower half portion. The journal bearing according to claim 5, wherein:   The journal bearing according to any one of claims 1 to 6, wherein an internal pressure of the first oil supply unit is greater than an internal pressure of the second oil supply unit.   A second oil supply source that supplies lubricating oil to the second oil supply unit, and a first oil supply source that supplies lubricant oil to the first oil supply unit at a pressure higher than that of the second oil supply source. Item 8. The journal bearing according to item 7. A rotating machine, wherein a rotor shaft is supported by the journal bearing according to any one of claims 1 to 8.

Images