Bearing device

Abstract

Provided is a technology capable of suppressing contact between a bearing which supports a thrust load of a rotary shaft and a collar facing the bearing. A bearing device 10 according to an embodiment of the present invention comprises: a collar 13 provided to a rotary shaft 20 and formed in a disk shape about the rotary shaft 20; and a thrust bearing 14 disposed to face the collar 13 in the axial direction along the rotary shaft 20. A surface, of the collar 13, facing the thrust bearing 14 has an inclined part 13A inclined such that the distance from the thrust bearing 14 to the inclined part 13A is larger outward in a radial direction about the rotary shaft 20.

Description

[Technical Field]

[0001] The present disclosure relates to a bearing device. [Background technology]

[0002] BACKGROUND ART Conventionally, a bearing that supports a thrust load on a rotating shaft of a high-speed rotating body is known (see Patent Document 1).

[0003] Patent Document 1 discloses that a dynamic pressure gas bearing is used to support the thrust load on the rotating shaft of an expansion turbine. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-150661 Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, there are cases where a bearing that supports the thrust load on the rotating shaft is arranged opposite a disk-shaped collar provided on the rotating shaft in an axial direction parallel to the rotating shaft (hereinafter simply referred to as "axial direction") (see Figure 4 described below).

[0006] However, for example, a sudden change in process conditions may cause the rotating shaft to run out. Furthermore, for example, abnormal vibrations may occur in the rotating shaft. Therefore, the runout or vibration of the rotating shaft may cause the rotating shaft to tilt, which may result in contact between the outer periphery of the collar and the bearing, leading to seizure.

[0007] In view of the above-mentioned problems, an object of the present invention is to provide a technique capable of suppressing contact between a bearing that supports the thrust load of a rotating shaft and a collar that faces the bearing. [Means for solving the problem]

[0008] In order to achieve the above object, in one embodiment of the present disclosure, a disc-shaped collar provided on the rotation shaft and centered on the rotation shaft; a thrust bearing disposed to face the collar in an axial direction along the rotation axis, the thrust bearing has an injection portion that is provided to face the collar in the axial direction and that injects gas toward the collar, a surface of the collar facing the thrust bearing has an inclined portion inclined outward in a radial direction based on the rotation axis so that a distance from the thrust bearing increases, The inclined portion is The aforementioned In the radial direction, the collar Between the inner periphery corresponding to the joint with the rotary shaft and the outer periphery The range includes the central portion of A bearing arrangement is provided. [Effects of the Invention]

[0009] According to the above-described embodiment, it is possible to suppress contact between the bearing that supports the thrust load of the rotating shaft and the collar that faces the bearing. [Brief explanation of the drawings]

[0010] [Figure 1] 1A and 1B are diagrams illustrating a first example of the structure of a bearing device. [Figure 2] FIG. 10 is a diagram showing a second example of the structure of the bearing device. [Figure 3] FIG. 1 is a diagram illustrating an example of the configuration of a hydrogen gas filling system. [Figure 4] FIG. 10 is a diagram showing a bearing device according to a comparative example. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment will be described with reference to the drawings.

[0012] [First example of bearing device] A first example of a bearing device 10 according to this embodiment will be described with reference to FIG.

[0013] FIG. 1 is a diagram showing a first example of the structure of a bearing device 10. As shown in FIG.

[0014] In this example, the up-down direction in the drawing corresponds to the vertical direction. Also, in the drawing, only a part (the housing 11 and the thrust bearing 14) is shown as a cross-sectional view. The same applies to FIG. 2 described below.

[0015] As shown in FIG. 1, a bearing device 10 supports a radial load and a thrust load on a rotating shaft 20 that rotates at high speed.

[0016] For example, as shown in Fig. 1, the rotation shaft 20 is installed so as to extend in the vertical direction. Alternatively, the rotation shaft 20 may be arranged so as to extend in the horizontal direction.

[0017] An impeller 30 of an expansion turbine (see FIG. 3) that expands the process gas is attached to one end (the lower end in this example) of the rotating shaft 20. The process gas is, for example, hydrogen gas (see FIG. 4). Alternatively, the process gas may be helium gas, nitrogen gas, or air.

[0018] An energy consuming unit 40 is attached to the other end (the upper end in this example) of the rotating shaft 20. The energy consuming unit 40 can consume the rotational energy of the rotating shaft 20 driven by the process gas. The energy consuming unit 40 is, for example, the impeller of a compressor (see FIG. 4). The energy consuming unit 40 may also be a brake fan for braking or a generator.

[0019] The rotation axis 20 may be upside down in the vertical direction.

[0020] As shown in FIG. 1, the bearing device 10 includes a housing 11, a radial bearing 12, a collar 13, and a thrust bearing 14.

[0021] Housing 11 accommodates radial bearing 12, collar 13, and thrust bearing 14 inside. Rotating shaft 20 passes through housing 11 in the vertical direction, and impeller 30 is attached to one end (lower end) of rotating shaft 20 that is exposed from one end (lower end) of housing 11, and energy consuming unit 40 is attached to the other end (upper end) of rotating shaft 20 that is exposed from the other end (upper end) of housing 11.

[0022] The radial bearing 12 supports a radial load on the rotating shaft 20. In this example, the radial bearing 12 is a dynamic pressure gas bearing. For example, as shown in FIG. 1, the radial bearing 12 is a tilting pad gas bearing. Alternatively, the radial bearing 12 may be a circular gas bearing or a foil gas bearing.

[0023] In this example, two radial bearings 12 are provided, one at each end in the axial direction inside the housing 11.

[0024] The collar 13 is attached to the rotary shaft 20 and has a disk shape centered on the rotary shaft 20. The collar 13 is provided inside the housing 11 at the center in the axial direction.

[0025] The collar 13 is configured to be able to receive a reaction force (hereinafter referred to as a "thrust reaction force") generated by the thrust bearing 14 in response to the thrust load of the rotary shaft 20.

[0026] The thrust bearing 14 supports a thrust load on the rotary shaft 20. Specifically, the thrust bearing 14 generates a thrust reaction force on the collar 13.

[0027] The thrust bearing 14 is disposed so as to face the collar 13 in the axial direction. For example, as shown in Fig. 1, two thrust bearings 14 are provided, and each is disposed so as to be adjacent to both one end (lower end) and the other end (upper end) of the rotating shaft 20 when viewed from the collar 13.

[0028] For example, as shown in FIG. 1 , the thrust bearing 14 is a hydrostatic gas bearing. Specifically, the thrust bearing 14 has injection holes 14A that inject a predetermined gas toward the collar 13. For example, the injection holes 14A are provided at predetermined intervals in a circumferential direction (hereinafter simply referred to as the "circumferential direction") based on the rotating shaft 20 of the thrust bearing 14. The injection holes 14A communicate with a gas supply path 14B that leads to the outside of the housing 11, and the predetermined gas is supplied to the injection holes 14A from the outside. The predetermined gas is, for example, the same gas as the process gas introduced into the expansion turbine including the impeller 30. In this case, the process gas before being introduced into the expansion turbine including the impeller 30 is branched and introduced into the gas supply path 14B. Alternatively, the predetermined gas may be a gas dedicated to the thrust bearing 14 that is different from the process gas introduced into the expansion turbine including the impeller 30. Alternatively, the thrust bearing 14 may be a hydrodynamic gas bearing that supports the thrust load of the rotating shaft 20 by gas film pressure between the thrust bearing 14 and the collar 13. In this case, the injection holes 14A are omitted. The thrust bearing 14 may be a combination of both the dynamic pressure type and the static pressure type.

[0029] The injection holes 14A (an example of an injection portion) are provided on the surface of the thrust bearing 14 facing the collar 13, and are formed so that the injection direction of the predetermined gas is in the axial direction. As a result, the predetermined gas injected from the injection holes 14A can generate a thrust reaction force in the collar 13. Furthermore, even if the rotating shaft 20 tilts due to runout or vibration of the rotating shaft 20, causing the collar 13 to approach the thrust bearing 14, the action of the injected predetermined gas can suppress abnormal approach due to an increase in the tilt of the rotating shaft 20, and prevent contact between the collar 13 and the thrust bearing 14.

[0030] The gas injected from the injection hole 14A may be released to the atmosphere or may be recovered. In the latter case, the recovered gas may be returned to the same path as the gas before being introduced into the expansion turbine.

[0031] The surface of the collar 13 facing the thrust bearing 14 is provided with an inclined portion 13A configured so that the distance from the thrust bearing 14 increases outward in the radial direction (hereinafter simply referred to as the "radial direction") relative to the rotating shaft 20. In this example, the surface of the thrust bearing 14 facing the collar 13 is configured as a surface perpendicular to the rotating shaft 20, i.e., a horizontal plane. Meanwhile, the inclined portion 13A is inclined at a constant angle from the radial center toward the radially outward direction, moving away from the facing surface (horizontal plane) of the thrust bearing 14. As a result, even if the rotating shaft 20 tilts due to runout or vibration of the rotating shaft 20 and the collar 13 approaches the thrust bearing 14, for example, the inclined portion 13A acts to maintain a relatively large distance between the radially outer end (outer periphery) of the collar 13 and the thrust bearing 14. This prevents the collar 13 from coming into contact with the thrust bearing 14.

[0032] The inclination angle of the inclined portion 13A with respect to a predetermined reference (for example, a horizontal plane) is set, for example, based on the maximum inclination angle defined for the radial bearing 12. Specifically, the inclination angle of the inclined portion 13A is set to be as small as possible within a range in which the radially outer end of the collar 13 does not come into contact with the thrust bearing 14 when the rotating shaft 20 is inclined to an angle corresponding to the maximum inclination angle of the radial bearing 12.

[0033] [Second example of bearing device] Next, a second example of the bearing device 10 according to this embodiment will be described.

[0034] The following description will focus on the differences from the first example described above, and the description of the same or corresponding configurations as the first example described above may be simplified or omitted.

[0035] FIG. 2 is a diagram showing a second example of the structure of the bearing device 10. In FIG.

[0036] As shown in FIG. 2, the bearing device 10 includes a housing 11, a radial bearing 12, a collar 13, and a thrust bearing 14, similar to the first example described above.

[0037] The collar 13 has an inclined portion 13A, similar to the first example described above.

[0038] In this example, the inclined portion 13A is provided only at a location on the surface of the collar 13 facing the thrust bearing 14 that is radially outward from the radial position where the ejection hole 14A of the thrust bearing 14 is provided. Specifically, the inclined portion 13A is inclined radially outward from a predetermined start position radially outward from the radial position where the ejection hole 14A of the thrust bearing 14 is provided to the radially outer end of the collar 13 so as to move away from the thrust bearing 14. On the other hand, the portion of the surface of the collar 13 facing the thrust bearing 14 that is radially inward from the start position of the inclined portion 13A is a horizontal plane, and the distance from the thrust bearing 14 is maintained constant. This makes it possible to maintain a relatively large distance between the radially outer end of the collar 13 and the thrust bearing 14, while maintaining a relatively small distance between the ejection hole 14A and the collar 13. Therefore, the action of the specified gas injected from the injection hole 14A can more appropriately apply thrust reaction force to the collar 13, and can more appropriately suppress the collar 13 from approaching the thrust bearing 14 due to the tilt of the rotating shaft 20.

[0039] [Other examples of bearing devices] Next, another example of the bearing device 10 according to this embodiment will be described.

[0040] The configurations of the first and second examples described above may be combined, modified, or changed as appropriate.

[0041] For example, in the first example described above, inclined portion 13A may be provided on only a portion of the radial direction of the surface of collar 13 facing thrust bearing 14, as in the second example described above. Specifically, in the first example described above, inclined portion 13A may be inclined radially outward from the radial center to a predetermined end position inside the radially outer end so as to move away from thrust bearing 14. In this case, the portion of the surface of collar 13 facing thrust bearing 14 that is radially outward from the end position of inclined portion 13A may be a horizontal plane, and the distance from thrust bearing 14 may be maintained constant.

[0042] Furthermore, in the second example described above, the inclined portion 13A may be inclined radially outward from a predetermined radial start position to a predetermined end position that is more inward than the outer radial end portion so as to move away from the thrust bearing 14. In this case, the portion of the surface of the collar 13 that faces the thrust bearing 14, which is radially outward from the end position of the inclined portion 13A, may be a horizontal plane, and the distance from the thrust bearing 14 may be maintained constant.

[0043] In the first and second examples and their modifications described above, the degree of inclination (inclination angle) of the inclined portion 13A may change continuously or stepwise in the radial direction.

[0044] [Examples of bearing device applications] Next, an application example of the bearing device 10 will be described with reference to FIG.

[0045] 3 is a diagram showing an application example of the bearing device 10. Specifically, FIG. 3 is a diagram showing an example of a hydrogen gas filling system 1.

[0046] The hydrogen gas filling system 1 is installed, for example, in a hydrogen station for filling a vehicle VCL with hydrogen gas.

[0047] As shown in FIG. 3, the hydrogen gas compression equipment 100 includes an expansion valve 200, a hydrogen gas line 300, and a pre-cooling system 400.

[0048] The hydrogen gas compression equipment 100 compresses hydrogen gas supplied from a tank, raises the pressure to a predetermined level, and outputs the gas.

[0049] The expansion valve 200 adiabatically expands (isenthalpic expands) the hydrogen gas output from the hydrogen gas compression equipment 100. At this time, since the temperature of the hydrogen gas before expansion is higher than the inversion temperature (-58°C), the temperature of the hydrogen gas after expansion rises due to the Joule-Thomson effect.

[0050] The hydrogen gas line 300 supplies the expanded hydrogen gas output from the expansion valve 200 to the pre-cooling system 400 .

[0051] The pre-cooling system 400 cools the hydrogen gas supplied from the hydrogen gas line 300 and supplies it to the dispenser 500 .

[0052] The pre-cooling system 400 includes a compressor 410 , a chiller 420 , a cold source 430 , and an expansion turbine 440 .

[0053] The compressor 410 compresses the hydrogen gas supplied from the hydrogen gas line 300 .

[0054] The cooler 420 exchanges heat between a refrigerant supplied from a cold heat source 430 and the hydrogen gas compressed by the compressor 410, thereby cooling the hydrogen gas.

[0055] The cold heat source 430 supplies a refrigerant having a temperature lower than that of the hydrogen gas output from the compressor 410 to the cooler 420 and circulates it.

[0056] A cooler similar to the cooler 420 may be provided upstream of the compressor 410, and the hydrogen gas in the hydrogen gas line 300 may be introduced into the compressor 410 after being cooled by the cooler.

[0057] The expansion turbine 440 expands the hydrogen gas cooled by the cooler 420. This expands the hydrogen gas and reduces its temperature. Furthermore, expanding the hydrogen gas compressed by the compressor 410 relatively increases the expansion ratio, and as a result, the temperature of the hydrogen gas can be reduced even more significantly. Therefore, the temperature of the hydrogen gas can be reduced to an appropriate level without requiring a pre-cooling system that requires a refrigerator equipment including, for example, a compressor, a condenser, an expansion valve, an evaporator, an accumulator, and the like.

[0058] In this example, the compressor 410 and the expansion turbine 440 are connected by a rotating shaft 20 supported by a bearing device 10. The expansion turbine 440 expands hydrogen gas using an impeller 30 attached to one end of the rotating shaft 20, while the compressor 410 compresses hydrogen gas using an impeller serving as an energy consuming unit 40 attached to the other end of the rotating shaft 20. This prevents contact between the collar 13 and the thrust bearing 14 of the bearing device 10, even if the rotating shaft 20 of the compressor 410 and the expansion turbine 440, which rotate at high speed, tilts due to vibration or vibration. This prevents seizure caused by contact between the collar 13 and the thrust bearing 14, which may require the compressor 410 and the expansion turbine 440 to be stopped or replaced, thereby preventing an impact on the operation of the hydrogen station.

[0059] The dispenser 500 fills the hydrogen tank TNK of the vehicle VCL with high-pressure hydrogen gas supplied from the pre-cooling system 400. The vehicle VCL is, for example, a fuel cell vehicle equipped with a fuel cell capable of generating electricity using hydrogen gas as fuel.

[0060] In this way, the bearing device 10 can be applied to the compressor 410 and the expansion turbine 440 of the pre-cooling system 400 in the hydrogen gas filling system 1.

[0061] [Effect] Next, the operation of the bearing device 10 according to this embodiment will be described with reference to FIG.

[0062] FIG. 4 is a diagram showing a bearing device 10c according to a comparative example.

[0063] In FIG. 4, the same components as those in the bearing device 10 according to this embodiment are denoted by the same reference numerals.

[0064] As shown in FIG. 4, the bearing device 10c includes a housing 11, a radial bearing 12, a collar 13c, and a thrust bearing .

[0065] The collar 13 c is configured to receive a thrust reaction force generated by the thrust bearing 14 in response to the thrust load of the rotary shaft 20 .

[0066] The surface of collar 13c facing thrust bearing 14 is a horizontal surface, and a constant distance is maintained between collar 13c and thrust bearing 14. Therefore, for example, if rotating shaft 20 tilts due to runout or vibration of rotating shaft 20, the radially outer end of collar 13 may approach and come into contact with thrust bearing 14. As a result, collar 13 or thrust bearing 14 may seize, which may require the compressor turbine including impeller 30 to be stopped or may make it impossible to restart and require parts to be replaced.

[0067] In contrast, in this embodiment, bearing device 10 is provided on rotating shaft 20 and includes a disk-shaped collar 13 centered on rotating shaft 20, and a thrust bearing 14 arranged to face collar 13 in the axial direction along rotating shaft 20. The surface of collar 13 facing thrust bearing 14 has an inclined portion 13A that is inclined outward in the radial direction based on rotating shaft 20 so that the distance from thrust bearing 14 increases.

[0068] This ensures a relatively large distance between the radial outer end of the collar 13 and the thrust bearing 14. Therefore, even if the rotating shaft 20 tilts due to runout or vibration of the rotating shaft 20, causing the collar 13 to approach the thrust bearing 14, contact between the collar 13 and the thrust bearing 14 can be suppressed.

[0069] In this embodiment, the thrust bearing 14 may be provided with an injection hole 14A for injecting gas toward the collar 13.

[0070] As a result, even if the rotating shaft 20 tilts due to runout or vibration of the rotating shaft 20 and the collar 13 approaches the thrust bearing 14, the gas injected from the injection holes 14A to the collar 13 can prevent the tilt of the rotating shaft 20 from increasing. Therefore, contact between the collar 13 and the thrust bearing 14 can be further prevented.

[0071] In this embodiment, the inclined portion 13A may be formed on the collar 13 radially outward from a position axially facing the injection hole 14A.

[0072] This makes it possible to maintain a relatively small distance between the ejection hole 14A and the thrust bearing 14 at the radially outer end portion, while maintaining a relatively large distance between the ejection hole 14A and the thrust bearing 14 at the facing surface of the collar 13 facing the thrust bearing 14. Therefore, contact between the collar 13 and the thrust bearing 14 can be further suppressed.

[0073] Although the embodiments have been described in detail above, the present disclosure is not limited to such specific embodiments, and various modifications and variations are possible within the scope of the gist described in the claims. [Explanation of symbols]

[0074] 1 Hydrogen gas filling system 10 Bearing device 11. Housing 12 Radial bearing 13 Colors 13A Inclined section 14 Thrust bearing 14A injection hole 14B Gas supply route 20 Rotation axis 30 impeller 40 Energy consumption unit 200 Expansion valve 300 Hydrogen gas line 400 Pre-cool System 410 Compressor 420 Cooler 430 Cold source 440 Expansion Turbine 500 Dispensers TNK hydrogen tank VCL vehicle

Claims

[Claim 1] a disc-shaped collar provided on the rotation shaft and centered on the rotation shaft; a thrust bearing disposed to face the collar in an axial direction along the rotation axis, the thrust bearing has an injection portion that is provided to face the collar in the axial direction and that injects gas toward the collar, a surface of the collar facing the thrust bearing has an inclined portion inclined outward in a radial direction based on the rotation axis so that a distance from the thrust bearing increases, the inclined portion is provided in a range including a central portion between an inner peripheral edge corresponding to a coupling portion of the collar with the rotation shaft and an outer peripheral edge in the radial direction, Bearing device.

Images