Geared compressor

Abstract

This geared compressor comprises a drive shaft extending in a first direction, a main gear fixed to the drive shaft, a first auxiliary gear meshing with the main gear, a second auxiliary gear meshing with the main gear, a first shaft fixed to the first auxiliary gear, a second shaft fixed to the second auxiliary gear, a pair of first bearings rotatably supporting the first shaft, a pair of second bearings rotatably supporting the second shaft, and a casing. The casing has a casing side plate extending across a plane intersecting the first direction, a pair of first bearing housings fixed to the casing side plate and fixing each of the pair of first bearings, and a pair of second bearing housings fixed to the casing side plate and fixing each of the pair of second bearings. The casing side plate is formed to be thinner in the first direction than the first bearing housings and the second bearing housings, and the second bearing housings are formed to be thinner in the first direction than the first bearing housings.

Description

Geared Compressor

[0001] The present disclosure relates to a geared compressor. The present application claims priority based on Japanese Patent Application No. 2025-027634 filed in Japan on February 25, 2025, the content of which is incorporated herein by reference.

[0002] A centrifugal compressor, which is a type of rotating machine, compresses fluid by causing the fluid to pass through in the radial direction of a rotating impeller and utilizing the centrifugal force generated during this process.

[0003] For example, Patent Document 1 discloses a gear-driven turbo compressor (geared compressor) as one type of such centrifugal compressors, the compressor including a large gear shaft having a large gear rotationally driven by a drive device, a pinion shaft having a pinion that meshes with the large gear, and an impeller fixed to an end of the pinion shaft.

[0004] International Publication No. 2010 / 095507

[0005] Incidentally, in such a geared compressor, there are cases where a casing that accommodates the large gear and the pinion has an integrally formed portion through which the large gear shaft is inserted and a portion through which the pinion shaft is inserted. In such cases, the degree of freedom in designing the casing is reduced. Furthermore, the overall weight of the geared compressor increases. Therefore, there is a demand for a configuration that can further reduce the overall weight of the geared compressor.

[0006] The present disclosure provides a geared compressor with further reduced weight.

[0007] The geared compressor according to this disclosure includes a drive shaft extending around an axis extending in a first direction and rotated about the axis, a main gear fixed to the drive shaft and rotating together with the drive shaft around the axis, a first sub-gear that meshes with the main gear and rotates, a second sub-gear positioned on the opposite side of the first sub-gear with respect to the main gear in a second direction intersecting the first direction and meshing with the main gear and rotating, a first shaft fixed to the first sub-gear and extending in the first direction, a second shaft fixed to the second sub-gear and extending in the first direction, a pair of first bearings rotatably supporting the first shaft and positioned apart in the first direction, and a pair of bearings rotatably supporting the second shaft and positioned apart in the first direction The gear comprises a pair of second bearings arranged apart in the first direction, and a casing that houses the main gear, the first auxiliary gear, and the second auxiliary gear. The casing has a casing side plate extending in a plane intersecting the first direction, a pair of first bearing housings fixed to the casing side plate and each fixing the pair of first bearings, and a pair of second bearing housings fixed to the casing side plate and each fixing the pair of second bearings. The casing side plate is formed to be thinner in the first direction than the first bearing housing and the second bearing housing, and the second bearing housing is formed to be thinner in the first direction than the first bearing housing.

[0008] According to the geared compressor of this disclosure, the weight can be further reduced.

[0009] This is a schematic horizontal cross-sectional view showing the configuration of a geared compressor according to an embodiment of the present disclosure. This is a plan view of the geared compressor according to an embodiment of the present disclosure, viewed from a first direction. This is a diagram showing the configuration of a geared compressor according to an embodiment of the present disclosure, and is a cross-sectional view taken along the line III-III in Figure 1. This is a schematic horizontal cross-sectional view showing the configuration of a geared compressor that is a comparative example of the geared compressor according to an embodiment of the present disclosure.

[0010] Hereinafter, embodiments for implementing the geared compressor 1 according to the present invention will be described with reference to Figures 1 to 3. However, this disclosure is not limited to these embodiments.

[0011] (Configuration of the geared compressor) Figure 1 is a schematic horizontal cross-sectional view showing the configuration of the geared compressor 1 according to this embodiment. The geared compressor 1 has a multi-axis, multi-stage configuration that compresses fluid by rotating multiple impellers by rotating multiple gears. The geared compressor 1 includes a drive shaft 10, a main gear 12, a first auxiliary gear 22, a second auxiliary gear 32, a first shaft 20, a second shaft 30, a pair of first bearings 24, a pair of second bearings 34, a first impeller 26, a second impeller 36, a casing 50, and a supply pipe 80.

[0012] (Drive shaft) The drive shaft 10 extends around an axis O that extends in the first direction D1. The drive shaft 10 is formed in a cylindrical shape around the axis O. The drive shaft 10 is provided so as to penetrate the casing 50 in the first direction D1. The drive shaft 10 is made rotatable around the axis O by a drive source (not shown). As a drive source, for example, an electric motor, a steam turbine, etc., can be used. The drive shaft 10 is rotatably supported relative to the casing 50 by a bearing (journal bearing) (not shown).

[0013] (Main Gear) The main gear 12 is fixed to the drive shaft 10. The main gear 12 is rotatable together with the drive shaft 10 around axis O. The main gear 12 transmits the rotation of the drive shaft 10 to the first auxiliary gear 22 and the second auxiliary gear 32. The main gear 12 is an external gear formed in the shape of a disc with axis O as its center. In this embodiment, the main gear 12 has a larger outer diameter than the first auxiliary gear 22 and the second auxiliary gear 32. The main gear 12 is housed inside the casing 50.

[0014] (First Sub-Gear) The first sub-gear 22 rotates in mesh with the main gear 12. The first sub-gear 22 is fixed to or integrated with the first shaft 20. The first sub-gear 22 is positioned on the first side D2a of the second direction D2, which intersects the first direction D1 with respect to the main gear 12. The first sub-gear 22 is an external gear formed in the shape of a disc with a first centerline O1 that extends parallel to the axis O on the first side D2a of the second direction D2 with respect to the axis O. The first sub-gear 22 rotates around the first centerline O1 as the main gear 12 rotates. In this embodiment, the first sub-gear 22 is formed with a smaller outer diameter than the main gear 12. The first sub-gear 22 is housed inside the casing 50.

[0015] (Second Sub-Gear) The second sub-gear 32 rotates in mesh with the main gear 12. The second sub-gear 32 is fixed to or integrated with the second shaft 30. The second sub-gear 32 is positioned on the second side D2b of the second direction D2 with respect to the main gear 12. That is, the second sub-gear 32 is positioned on the opposite side of the first sub-gear 22 with respect to the main gear 12 in the second direction D2. The second sub-gear 32 is an external gear formed in the shape of a disc with a second centerline O2 that extends parallel to the axis O on the second side D2b of the second direction D2 with respect to the axis O. The second sub-gear 32 rotates around the second centerline O2 as the main gear 12 rotates. In this embodiment, the second sub-gear 32 is formed with a smaller outer diameter than the main gear 12. The second sub-gear 32 is housed inside the casing 50.

[0016] In this embodiment, directions are defined as follows: As described above, the direction in which the axis O extends is defined as the first direction D1. The direction that intersects (for example, perpendicular to) the axis O is defined as the second direction D2. Furthermore, the direction that intersects (for example, perpendicular to) the first direction D1 and the second direction D2 is defined as the third direction D3. The third direction D3 is the vertical direction. That is, the first direction D1 and the second direction D2 are the horizontal directions. For the sake of explanation, with respect to the first direction D1, the upper side in Figure 1 is defined as one side D1a of the first direction D1, and the lower side in Figure 1 is defined as the other side D1b of the first direction D1. For example, a drive source (not shown) is located outside the casing 50 on one side D1a of the drive shaft 10 in the first direction D1.

[0017] (First shaft) The first shaft 20 is fixed to or integrated with the first sub-gear 22. The first shaft 20 extends in the first direction D1. The first shaft 20 is formed in a cylindrical shape with respect to the first centerline O1. The first shaft 20 is positioned away from the axis O on the first side D2a of the second direction D2. The first shaft 20 is provided so as to penetrate the casing 50 in the first direction D1. The first shaft 20 is rotatably supported by a pair of first bearings 24. The first shaft 20 is rotatable about the first centerline O1 as the drive shaft 10 rotates.

[0018] (Second shaft) The second shaft 30 is fixed to or integrated with the second auxiliary gear 32. The second shaft 30 extends in the first direction D1. The second shaft 30 is formed in a cylindrical shape with respect to the second centerline O2. The second shaft 30 is positioned away from the axis O on the second side D2b in the second direction D2. The second shaft 30 is provided so as to penetrate the casing 50 in the first direction D1. The second shaft 30 is rotatably supported by a pair of second bearings 34. The second shaft 30 is rotatable about the second centerline O2 as the drive shaft 10 rotates.

[0019] In this embodiment, the second shaft 30 is formed in a cylindrical shape with a smaller diameter than the first shaft 20. Furthermore, the second shaft 30 is shorter than the first shaft 20 in the first direction D1. Moreover, as shown in Figure 2, the drive shaft 10, the first shaft 20, and the second shaft 30 in this embodiment are arranged so that their centers are at the same height in the third direction D3. In other words, the drive shaft 10, the first shaft 20, and the second shaft 30 are arranged so that their centers are aligned in a straight line. That is, the axis O, the first center line O1, and the second center line O2 are arranged at the same height in the third direction D3 (vertical direction) so that they lie on the same virtual plane.

[0020] (First Bearing) The first bearing 24 rotatably supports the first shaft 20 relative to the casing 50. The first bearing 24 is a journal bearing. As shown in Figure 1, a pair of first bearings 24 are arranged apart in the first direction D1. The pair of first bearings 24 are arranged so as to sandwich the first sub-gear 22 in the first direction D1. Both the pair of first bearings 24 are fixed to the casing 50. The distance between the pair of first bearings 24 in the first direction D1 is denoted as the first bearing span L1. More specifically, the first bearing span L1 is the distance between the centers of each first bearing 24 in the first direction D1.

[0021] (Second bearing) The second bearing 34 rotatably supports the second shaft 30 relative to the casing 50. The second bearing 34 is a journal bearing. The second bearing 34 is arranged in pairs, separated in the first direction D1. The second bearing 34 is arranged in pairs so as to sandwich the second auxiliary gear 32 in the first direction D1. Both the pair of second bearings 34 are fixed to the casing 50. Due to the relationship between the diameters of the first shaft 20 and the second shaft 30, the inner diameter of the second bearing 34 is smaller than that of the first bearing 24. Also, the width of the second bearing 34 in the first direction D1 is smaller than that of the first bearing 24.

[0022] For a pair of second bearings 34, the distance in the first direction D1 is defined as the second bearing span L2. More specifically, the second bearing span L2 is the distance between the centers of each second bearing 34 in the first direction D1. In this embodiment, the relationship between the first bearing span L1 and the second bearing span L2 is such that L2 / L1 is less than 1. Preferably, the value of L2 / L1 is 0.9 or less.

[0023] (Impeller) The first shaft 20 and the second shaft 30 are equipped with impellers at both ends in the first direction D1. The first shaft 20 has a first impeller 26 fixed to both ends in the first direction D1. The second shaft 30 has a second impeller 36 fixed to both ends in the first direction D1. The first impeller 26 and the second impeller 36 compress the fluid. In this embodiment, the second impeller 36 compresses the fluid at a higher pressure than the first impeller 26. For example, the second impeller 36 compresses the fluid that has been compressed by the first impeller 26. That is, the second shaft 30 is capable of rotating at a higher speed than the first shaft 20. Also, the second impeller 36 is smaller in size than the first impeller 26. Note that the pair of first impellers 26 may be of different sizes. Similarly, the pair of second impellers 36 may be of different sizes.

[0024] (Casing Configuration) The casing 50 is formed to house the main gear 12, the first auxiliary gear 22, and the second auxiliary gear 32 inside. As shown in Figure 2, the casing 50 has an upper casing 50A and a lower casing 50B. The upper casing 50A and the lower casing 50B are formed to divide the casing 50 in a third direction D3. Specifically, the casing side plate 52, the closing plate 53, the first bearing housing 60, and the second bearing housing 70 are separable in the third direction D3. In the following description, only the lower casing 50B will be explained. For example, in Figure 3, the upper casing 50A is omitted. As shown in Figure 1, the casing 50 includes a casing side plate 52, a closing plate 53, a pair of first bearing housings 60, a pair of second bearing housings 70, a bearing support portion 54, and a bottom plate 56.

[0025] (Casing side plate) The casing side plate 52 extends in a plane that intersects the first direction D1. That is, the casing side plate 52 extends in the second direction D2 and the third direction D3. The casing side plate 52 is formed to have a constant thickness in the first direction D1 across its entire surface. The casing side plate 52 is formed to be thinner in the first direction D1 than the first bearing housing 60 and the second bearing housing 70. The casing side plate 52 is formed so that the drive shaft 10, the first shaft 20 and the second shaft 30 can be inserted through it. A pair of casing side plates 52 are arranged spaced apart in the first direction D1 so as to sandwich the main gear 12, the first auxiliary gear 22 and the second auxiliary gear 32 in the first direction D1. The casing side plate 52 is fixed to the bottom plate 56 at its lower end in the third direction D3. The bottom plate 56 is a plate-shaped member that extends horizontally.

[0026] (Blocking plate) The blocking plate 53 extends in a plane that intersects the second direction D2. That is, the blocking plate 53 extends in the first direction D1 and the third direction D3. A pair of blocking plates 53 are arranged spaced apart in the second direction D2 so as to block a pair of casing side plates 52 in the second direction D2. That is, the pair of blocking plates 53 are arranged to sandwich the main gear 12, the first auxiliary gear 22, and the second auxiliary gear 32 in the second direction D2.

[0027] (First Bearing Housing) The first bearing housing 60 fixes the first bearing 24. The first bearing housing 60 is fixed to the casing side plate 52. The first bearing housings 60 are arranged in pairs, each fixing a pair of first bearings 24. That is, the first bearing housings 60 are arranged in pairs spaced apart in the first direction D1. The shape of the first bearing housing 60 when viewed from the first direction D1 is annular. The first bearing housing 60 is fixed to the first bearing 24 on its inner circumferential surface and to the casing side plate 52 on its outer circumferential surface. The first bearing housing 60 is also spaced apart from the drive shaft 10 in the second direction D2.

[0028] In a pair of first bearing housings 60, the surfaces facing each other in the first direction D1 (facing inward in the first direction D1) are defined as the inner surfaces 62 of the first housings. In the pair of first bearing housings 60, the surfaces facing outward in the first direction D1 are defined as the outer surfaces 64 of the first housings. In the first bearing housings 60, the inner surfaces 62 of the first housings are arranged to be coplanar with the inner surface of the casing side plate 52. In addition, in the first bearing housings 60, the outer surfaces 64 of the first housings protrude in the first direction D1 beyond the outer surface of the casing side plate 52. That is, in the first bearing housings 60, the thickness in the first direction D1 is greater than that of the casing side plate 52. Furthermore, in the first bearing housings 60, the thickness in the first direction D1 is formed to be approximately the same as that of the first bearing 24.

[0029] (Second Bearing Housing) The second bearing housing 70 fixes the second bearing 34. The second bearing housing 70 is fixed to the casing side plate 52. The second bearing housing 70 is arranged in pairs, each fixing a pair of second bearings 34. That is, the second bearing housings 70 are arranged in pairs spaced apart in the first direction D1. The shape of the second bearing housing 70 when viewed from the first direction D1 is annular. The second bearing housing 70 is fixed to the second bearing 34 on its inner circumferential surface and to the casing side plate 52 on its outer circumferential surface. The second bearing housing 70 is also spaced apart from the drive shaft 10 in the second direction D2. Note that the outer diameter of the second bearing housing 70 is smaller than that of the first bearing housing 60 due to the relationship between the diameters of the first shaft 20 and the second shaft 30.

[0030] In a pair of second bearing housings 70, the surfaces facing each other in the first direction D1 (facing inward in the first direction D1) are defined as the inner surfaces 72 of the second housings. In the pair of second bearing housings 70, the surfaces facing outward in the first direction D1 are defined as the outer surfaces 74 of the second housings. In the second bearing housings 70, the inner surfaces 72 of the second housings are arranged to be coplanar with the inner surface of the casing side plate 52. In addition, in the second bearing housings 70, the outer surfaces 74 of the second housings protrude in the first direction D1 beyond the outer surface of the casing side plate 52. That is, the second bearing housings 70 are formed to be thicker in the first direction D1 than the casing side plate 52. Furthermore, the second bearing housings 70 are formed so that their thickness in the first direction D1 is approximately the same as that of the second bearing 34.

[0031] As described above, in the first direction D1, the distance between the pair of inner surfaces 62 of the first housing is equal to the distance between the pair of inner surfaces 72 of the second housing. On the other hand, in the first direction D1, the distance between the pair of outer surfaces 64 of the first housing is greater than the distance between the pair of outer surfaces 74 of the second housing. In other words, the second bearing housing 70 is formed to be thinner in the first direction D1 than the first bearing housing 60.

[0032] (Bearing support section) The bearing support section 54 is formed and positioned to support the first bearing housing 60 and the second bearing housing 70 from below in the vertical direction. The bearing support section 54 is fixed to the outer surface of the casing side plate 52 and extends vertically. The bearing support section 54 connects each of the first bearing housing 60 and the second bearing housing 70 to the bottom plate 56 in a third direction D3. That is, the bearing support section 54 is positioned to support each of the first bearing housing 60 and the second bearing housing 70. As shown in Figures 2 and 3, the bearing support section 54 extends from below the first bearing housing 60 and the second bearing housing 70 in the third direction D3.

[0033] Furthermore, the bearing support portion 54 is positioned in the second direction D2 such that its centers coincide with those of the first shaft 20 or the second shaft 30. The bearing support portion 54 is formed to be narrower in width than the first bearing housing 60 and the second bearing housing 70 in the second direction D2. In addition, the bearing support portion 54 is formed such that its end in the first direction D1 is nearly coplanar with the outer surface 64 of the first housing or the outer surface 74 of the second housing (see Figure 3). The bearing support portion 54 may be adjusted to the required size according to the first bearing housing 60 and the second bearing housing 70, respectively.

[0034] (Supply pipe) The supply pipe 80 is arranged to supply lubricating oil to the first bearing 24 and the second bearing 34. The supply pipe 80 is formed so that lubricating oil can flow through its interior. In this embodiment, at least a portion of the supply pipe 80 is arranged inside the casing 50, and a pair is provided so as to sandwich the main gear 12, the first auxiliary gear 22, and the second auxiliary gear 32 in the first direction D1. The supply pipe 80 is positioned so as not to interfere with the parts that are driven. The supply pipe 80 comprises a main supply pipe portion 82 and branch portions 84.

[0035] The main supply pipe 82 is positioned extending in the second direction D2. The main supply pipe 82 is capable of supplying lubricating oil from the first side D2a to the second side D2b in the second direction D2 by a pumping device (not shown). That is, the supply pipe 80 in this embodiment is formed to supply lubricating oil by branching it into two from the pumping device. The branch section 84 is formed to branch out from the main supply pipe 82 toward the first direction D1. The branch section 84 is inserted into the first bearing housing 60 or the second bearing housing 70, and is capable of supplying lubricating oil to the first bearing 24 or the second bearing 34.

[0036] <Effects and Effects> As a comparative example of the geared compressor 1 described above, a geared compressor 1c as shown in Figure 4 will be explained. The geared compressor 1c of the comparative example differs from the geared compressor 1 of the embodiment in the form of the casing 50c through which the drive shaft 10, the first shaft 20, and the second shaft 30c pass. In the casing 50c of the comparative example, the part through which the drive shaft 10, the first shaft 20, and the second shaft 30c pass is a single bearing housing 60c. The bearing housing 60c is formed with a constant thickness in the first direction D1. Furthermore, the bearing housing 60c is formed to match the thickness of the first bearing 24 in the first direction D1, and is approximately the same as the first bearing 24. In other words, the bearing housing 60c is the first bearing housing 60 of the embodiment extended in the second direction D2.

[0037] In the comparative example, the second bearing 34 is fixed to the central portion of the bearing housing 60c in the first direction. Therefore, in the first direction, the distance between the pair of first bearings 24 and the distance between the pair of second bearings 34 are the same. Also, in the comparative example, the second shaft 30c is formed to have the same length as the first shaft 20 in the first direction. Furthermore, the supply pipe 80c in the comparative example is a hole formed in the bearing housing 60c near the first bearing 24 and the second bearing 34, respectively. That is, in the comparative example, it is configured to supply lubricating oil from the pressure feeding equipment in four separate branches.

[0038] In the geared compressor 1 of this embodiment, the first shaft 20 and the second shaft 30 are supported by a first bearing 24 and a second bearing 34, respectively, which are fixed to a first bearing housing 60 and a second bearing housing 70, which are separate components. The casing side plate 52 is formed to be thinner in the first direction D1 than the first bearing housing 60 and the second bearing housing 70. The second bearing housing 70 is formed to be thinner in the first direction D1 than the first bearing housing 60. With this configuration, the casing 50 is configured to have the necessary rigidity to support the first shaft 20 and the second shaft 30, respectively. In other words, the casing 50 is adjusted to the minimum thickness necessary to support the first shaft 20 and the second shaft 30, respectively.

[0039] Specifically, the first bearing housing 60 is formed to be thicker in the first direction D1 than the second bearing housing 70. This allows for stable support of the first shaft 20, which has a larger diameter than the second shaft 30. In other words, the casing 50 can be constructed without making the second bearing housing 70 unnecessarily thick. Furthermore, the casing side plate 52 is formed to be thinner in the first direction D1 than the first bearing housing 60 and the second bearing housing 70. This allows for stable support of the first shaft 20 and the second shaft 30, and also reduces the overall weight of the casing 50. Therefore, the weight of the geared compressor 1 can be further reduced.

[0040] In other words, compared to the comparative example geared compressor 1c, the geared compressor 1 of this embodiment has improved design flexibility for the casing 50 by separating the first bearing housing 60 and the second bearing housing 70. Furthermore, by separating the first bearing housing 60 and the second bearing housing 70, the overall weight of the casing 50 can be reduced. Reducing the weight of the geared compressor 1 (casing 50) offers advantages such as reduced manufacturing costs and reduced transportation costs.

[0041] Furthermore, the distance between the pair of inner surfaces 62 of the first housing is equal to the distance between the pair of inner surfaces 72 of the second housing, and the distance between the pair of outer surfaces 64 of the first housing is greater than the distance between the pair of outer surfaces 74 of the second housing. As a result, the first bearing housing 60 and the second bearing housing 70 are arranged at the same distance inside the casing 50. Therefore, the thickness of the first bearing housing 60 and the second bearing housing 70 can be changed without changing (increasing) the internal space of the casing 50. In other words, the overall weight of the casing 50 can be reduced while keeping the size of the internal space of the casing 50 constant. In addition, the design freedom of the casing 50 can be improved.

[0042] Furthermore, the casing 50 of this embodiment has a bearing support portion 54 that is fixed to the casing side plate 52 and extends vertically (third direction D3), supporting the first bearing housing 60 and the second bearing housing 70 from below in the vertical direction. As a result, the first bearing housing 60 and the second bearing housing 70 are supported from below in the vertical direction by the bearing support portion 54. The bearing support portion 54 is adjusted to the required size according to the first bearing housing 60 and the second bearing housing 70, respectively. Therefore, sufficient rigidity can be obtained to stably support the first bearing 24 and the second bearing 34 while keeping the thickness of the casing side plate 52 down. Consequently, the first shaft 20 and the second shaft 30 can be supported more stably while keeping the overall weight of the casing 50 down.

[0043] Furthermore, in this embodiment, the second impeller 36 fixed to the second shaft 30 is configured to compress fluids at a higher pressure than the first impeller 26 fixed to the first shaft 20. The relationship between the first bearing span L1 and the second bearing span L2 is such that L2 / L1 is less than 1. In this case, the first bearing housing 60 and the second bearing housing 70 are formed to the required thickness for the first shaft 20 and the second shaft 30, respectively, without changing (increasing) the internal space of the casing 50. As a result, the second shaft 30 can be formed shorter than the first shaft 20. With this configuration, the weight of the casing 50 can be reduced, and the second bearing span L2 can be shortened, thereby increasing the eigenvalue of the rotor of the second shaft 30. As a result, the second shaft 30 can rotate at a higher speed, and the performance of the impeller can be improved. Thus, the compression performance can be improved while reducing the weight of the geared compressor 1.

[0044] Furthermore, according to the configuration of the supply pipe 80 of the present embodiment, the supply pipe branches from the main supply pipe portion 82 to the branch portion 84, and is capable of supplying lubricating oil to the first bearing 24 and the second bearing 34. According to this configuration, compared with the configuration of the supply pipe 80c in the comparative example, it is possible to supply lubricating oil while reducing the number of pipe branches from the pressure feeding equipment. In other words, according to the present embodiment, the configuration of piping and the like related to pressure feeding equipment for supplying lubricating oil can be simplified. Further, according to the present embodiment, lubricating oil can be supplied to the first bearing 24 and the second bearing 34 without forming a hole penetrating the casing 50 in the second direction D2. Therefore, the degree of freedom in design of the casing 50 can be improved while maintaining the rigidity of the casing 50.

[0045] <Other Embodiments> The embodiments of the present disclosure have been described in detail above with reference to the drawings. However, the specific configuration is not limited to these embodiments, and design changes and the like within a scope that does not deviate from the gist of the present disclosure are also included herein.

[0046] For example, the geared compressor 1 of the embodiment is a two-shaft four-stage compression centrifugal compressor, but is not limited thereto. Specifically, the geared compressor may be a compressor with three shafts and five or more compression stages.

[0047] Further, the casing 50 of the present embodiment can be divided into an upper casing 50A and a lower casing 50B, but is not limited to this configuration. For example, the casing 50 may be of a form that can be further subdivided.

[0048] <Additional Notes> The geared compressor 1 described in the embodiment can be understood, for example, as follows.

[0049] (1) The geared compressor 1 according to the first embodiment includes a drive shaft 10 that extends around an axis O extending in a first direction D1 and is rotationally driven around the axis O, a main gear 12 fixed to the drive shaft 10 and rotating together with the drive shaft 10 around the axis O, a first sub-gear 22 that meshes with the main gear 12 and rotates, a second sub-gear 32 that is positioned on the opposite side of the first sub-gear 22 with respect to the main gear 12 in a second direction D2 intersecting the first direction D1 and meshes with the main gear 12 and rotates, a first shaft 20 fixed to the first sub-gear 22 and extending in the first direction D1, a second shaft 30 fixed to the second sub-gear 32 and extending in the first direction D1, a pair of first bearings 24 that rotatably support the first shaft 20 and are positioned apart in the first direction D1, and the second shaft 30 that rotatably supports The system comprises a pair of second bearings 34 arranged apart in the first direction D1, a casing 50 that houses the main gear 12, the first auxiliary gear 22, and the second auxiliary gear 32, the casing 50 having a casing side plate 52 that extends in a plane intersecting the first direction D1, a pair of first bearing housings 60 fixed to the casing side plate 52 and each fixing the pair of first bearings 24, and a pair of second bearing housings 70 fixed to the casing side plate 52 and each fixing the pair of second bearings 34, the casing side plate 52 being formed to be thinner in the first direction D1 than the first bearing housing 60 and the second bearing housing 70, and the second bearing housing 70 being formed to be thinner in the first direction D1 than the first bearing housing 60.

[0050] In this geared compressor 1, the first shaft 20 and the second shaft 30 are supported by a first bearing 24 and a second bearing 34, respectively, which are provided in a first bearing housing 60 and a second bearing housing 70, which are separate components. The casing side plate 52 is formed to be thinner in the first direction D1 than the first bearing housing 60 and the second bearing housing 70. This allows for stable support of the first shaft 20 and the second shaft 30, while also reducing the overall weight of the casing 50. Therefore, the weight of the geared compressor 1 can be further reduced.

[0051] (2) The geared compressor 1 relating to the second embodiment is the geared compressor 1 of (1), wherein in a pair of first bearing housings 60, the distance between a pair of first housing inner surfaces 62 facing inward in the first direction D1 is equal to the distance between a pair of second housing inner surfaces 72 facing inward in the first direction D1 in a pair of second bearing housings 70, and in a pair of first bearing housings 60, the distance between a pair of first housing outer surfaces 64 facing outward in the first direction D1 is greater than the distance between a pair of second housing outer surfaces 74 facing outward in the first direction D1 in a pair of second bearing housings 70.

[0052] In this geared compressor 1, the first bearing housing 60 and the second bearing housing 70 are arranged at the same distance from each other inside the casing 50. Therefore, the thickness of the first bearing housing 60 and the second bearing housing 70 can be changed without increasing the internal space of the casing 50.

[0053] (3) The geared compressor 1 according to the third embodiment is the geared compressor 1 of (1) or (2), wherein the casing 50 is fixed to the casing side plate 52 and extends vertically, and has a bearing support portion 54 that supports the first bearing housing 60 and the second bearing housing 70 from below in the vertical direction.

[0054] In this geared compressor 1, the first bearing housing 60 and the second bearing housing 70 are supported vertically from below by the bearing support portion 54. Therefore, sufficient rigidity can be obtained while keeping the thickness of the casing side plate 52 low.

[0055] (4) The geared compressor 1 relating to the fourth embodiment is the geared compressor 1 of (1) to (3), wherein the first shaft 20 has first impellers 26 fixed to both ends in the first direction D1, and the second shaft 30 has second impellers 36 fixed to both ends in the first direction D1 for compressing a fluid at a higher pressure than the first impellers 26.

[0056] In this geared compressor 1, the first bearing housing 60 and the second bearing housing 70 are formed and arranged to the required thickness for the first shaft 20 and the second shaft 30, respectively. Therefore, the overall weight of the casing 50 can be reduced while ensuring sufficient rigidity.

[0057] According to the geared compressor of this disclosure, the weight can be further reduced.

[0058] 1...Geared compressor 10...Drive shaft 12...Main gear 20...First shaft 22...First auxiliary gear 24...First bearing 26...First impeller 30...Second shaft 32...Second auxiliary gear 34...Second bearing 36...Second impeller 50...Casing 50A...Upper casing 50B...Lower casing 52...Casing side plate 53...Closing plate 54...Bearing support part 56...Bottom plate 60...First bearing housing 62...Inner surface of first housing 64...Outer surface of first housing 70...Second bearing housing 72...Inner surface of second housing 74...Outer surface of second housing 80...Supply pipe 82...Main part of supply pipe 84...Branch part L1...First bearing span L2...Second bearing span O...Axis O1...First centerline O2...Second centerline D1...First direction D1a...One side D1b...Other side D2...Second direction D2a...first side D2b...second side D3...third direction

Claims

1. A drive shaft extending around an axis extending in a first direction and rotationally driven around the axis; a main gear fixed to the drive shaft and rotating together with the drive shaft around the axis; a first sub-gear meshing with the main gear and rotating; a second sub-gear positioned on the opposite side of the first sub-gear with respect to the main gear in a second direction intersecting the first direction and meshing with the main gear and rotating; a first shaft fixed to the first sub-gear and extending in the first direction; a second shaft fixed to the second sub-gear and extending in the first direction; a pair of first bearings rotatably supporting the first shaft and spaced apart in the first direction; a pair of second bearings rotatably supporting the second shaft and spaced apart in the first direction; and a casing housing the main gear, the first sub-gear, and the second sub-gear inside, wherein the casing comprises: casing side plates extending in a plane intersecting the first direction; and a pair of first bearing housings fixed to the casing side plates and each fixing a pair of the first bearings. A geared compressor comprising: a pair of second bearing housings fixed to the casing side plate and each fixing a pair of the second bearings, wherein the casing side plate is formed to be thinner in the first direction than the first bearing housing and the second bearing housing, and the second bearing housing is formed to be thinner in the first direction than the first bearing housing.

2. In a pair of first bearing housings, the distance between the inner surfaces of the pair of first housings facing inward in the first direction is equal to the distance between the inner surfaces of the pair of second housings facing inward in the first direction in a pair of second bearing housings, and in a pair of first bearing housings, the distance between the outer surfaces of the pair of first housings facing outward in the first direction is greater than the distance between the outer surfaces of the pair of second housings facing outward in the first direction in a pair of second bearing housings. The geared compressor according to claim 1.

3. The geared compressor according to claim 1 or 2, wherein the casing has bearing support portions that are fixed to the casing side plates and extend vertically, and support the first bearing housing and the second bearing housing from below in the vertical direction.

4. The geared compressor according to claim 1 or 2, wherein the first shaft has first impellers fixed to both ends in the first direction, and the second shaft has second impellers fixed to both ends in the first direction for compressing a fluid at a higher pressure than the first impeller.

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