Hydrostatic bearing spindle
By employing a special radial and thrust bearing configuration and magnetic attraction in the hydrostatic bearing spindle, the load problem during high-speed rotation is solved, improving load-bearing characteristics and preventing coating quality deterioration, thus achieving better mechanical protection and cost control.
Patent Information
- Application Number
- CN202511368375.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2024-09-27
- Filing Date
- 2025-09-24
- Publication Date
- 2026-03-27
AI Technical Summary
Existing hydrostatic bearing spindles are easily affected by gyroscopic torque and loads caused by shaft vibration when rotating at high speeds, resulting in insufficient load-bearing capacity.
A hydrostatic bearing spindle is designed, employing a special configuration of radial bearing bushings and thrust bearing bushings. Combined with the attractive force of a magnet in the thrust direction, radial and thrust bearings are formed to support the rotating shaft. The thrust bearing bushing and the magnet are configured on opposite sides of the radial bearing bushing side in the thrust direction, and the thrust bearing clearance is adjusted by adjusting the position of the magnet.
It improves the load-bearing characteristics of the hydrostatic bearing spindle, prevents coating quality deterioration, and achieves better mechanical protection and flexible rotation axis control by reducing magnet size and cost.
Smart Images
Figure CN121739002A_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to a hydrostatic bearing spindle. Background Technology
[0002] Japanese Patent No. 6935766 and Japanese Patent No. 7035594 disclose spindle assembly. Summary of the Invention
[0003] By changing the posture of the spindle assembly and altering the angle of the high-speed rotating shaft, a gyroscopic torque is generated on the rotating shaft. Furthermore, if there is a circumferential weight imbalance on the rotating shaft, it may vibrate when rotated. Thus, the gyroscopic torque and the load caused by the vibration of the rotating shaft act on it. This disclosure was made in view of the above-mentioned technical problems, and its object is to provide a hydrostatic bearing spindle with improved load-bearing characteristics.
[0004] The hydrostatic bearing spindle disclosed herein includes a rotating shaft, a radial bearing bushing, a thrust bearing bushing, and a magnet. The rotating shaft includes: a shaft portion extending in the thrust direction; a thrust plate extending radially from the shaft portion intersecting the thrust direction; and turbine blades disposed on the thrust plate. The radial bearing bushing is radially disposed opposite to the shaft portion. The thrust bearing bushing is disposed opposite to the thrust plate in the thrust direction. The magnet attracts the rotating shaft in the thrust direction. A radial bearing supporting the shaft portion is formed between the shaft portion and the radial bearing bushing. A thrust bearing supporting the rotating shaft in the thrust direction is formed between the thrust plate and the thrust bearing bushing. The thrust bearing bushing and the magnet are disposed in the thrust direction opposite to the radial bearing bushing side relative to the thrust plate. The distance in the thrust direction from the thrust bearing to the center of the radial bearing in the thrust direction is larger than the diameter of the center of the radial thrust bearing.
[0005] The above and other objects, features, aspects and advantages of this disclosure will become apparent from the following detailed description of this disclosure, which will be understood in conjunction with the accompanying drawings. Attached Figure Description
[0006] Figure 1 This is a schematic cross-sectional view of the hydrostatic bearing spindle of the embodiment.
[0007] Figure 2 This is a rear view of the rotating shaft included in the hydrostatic bearing spindle of the embodiment.
[0008] Figure 3 This is a schematic cross-sectional view of a hydrostatic bearing spindle with a bell-shaped cup configuration.
[0009] Figure 4 This is a schematic cross-sectional view of a hydrostatic bearing spindle installed in a spindle retainer embodiment.
[0010] Figure 5 This is a schematic cross-sectional view of the hydrostatic bearing spindle of the first variation of the embodiment.
[0011] Figure 6 This is a partially enlarged rough cross-sectional view of the hydrostatic bearing spindle of the first example of the second variation of the embodiment.
[0012] Figure 7 This is a partially enlarged rough cross-sectional view of the hydrostatic bearing spindle of the second example of the second variation of the embodiment.
[0013] Figure 8 This is a partially enlarged rough cross-sectional view of the hydrostatic bearing spindle of the third example of the second variation of the embodiment.
[0014] Figure 9 This is a partially enlarged rough cross-sectional view of the hydrostatic bearing spindle of the third variation of the embodiment.
[0015] Figure 10 This is a partially enlarged rough cross-sectional view of the radial bearing of the hydrostatic bearing spindle in the first example of the fourth variation of the embodiment.
[0016] Figure 11 This is a partially enlarged rough cross-sectional view of the thrust bearing of the hydrostatic bearing spindle in the first example of the fourth variation of the embodiment.
[0017] Figure 12 This is a partially enlarged rough cross-sectional view of the radial bearing of the hydrostatic bearing spindle in the second example of the fourth variation of the embodiment.
[0018] Figure 13 This is a partially enlarged rough cross-sectional view of the thrust bearing of the hydrostatic bearing spindle in the second example of the fourth variation of the embodiment.
[0019] Figure 14 This is a partially enlarged rough cross-sectional view of the radial bearing of the hydrostatic bearing spindle in the third example of the fourth variation of the embodiment.
[0020] Figure 15 This is a partially enlarged rough cross-sectional view of the thrust bearing of the hydrostatic bearing spindle in the third example of the fourth variation of the embodiment.
[0021] Figure 16 This is a partially enlarged rough cross-sectional view of the radial bearing of the hydrostatic bearing spindle in the fourth example of the fourth variation of the embodiment.
[0022] Figure 17 This is a partially enlarged rough cross-sectional view of the thrust bearing of the hydrostatic bearing spindle in the fourth example of the fourth variation of the embodiment.
[0023] Figure 18This is a partially enlarged rough cross-sectional view of the radial bearing of the hydrostatic bearing spindle in the fifth example of the fourth variation of the embodiment.
[0024] Figure 19 This is a partially enlarged rough cross-sectional view of the thrust bearing of the hydrostatic bearing spindle in the fifth example of the fourth variation of the embodiment. Detailed Implementation
[0025] The embodiments of this disclosure will be described in detail based on the accompanying drawings. Furthermore, in the following drawings, the same or equivalent parts are labeled with the same reference numerals, and their descriptions are not repeated. At least a portion of the structures of the embodiments described below can be combined arbitrarily.
[0026] Reference Figures 1 to 4 The hydrostatic bearing spindle 1 of the embodiment will be described. The hydrostatic bearing spindle 1 is used, for example, in an electrostatic coating machine. The hydrostatic bearing spindle 1 includes a rotating shaft 10, a housing assembly 20, a cover 27, multiple O-rings 41, 42, 43, and 44, a thrust bearing bushing 50, a magnet 55, and a housing 57. The hydrostatic bearing spindle 1 may also further include a bell-shaped cup 19 (see reference). Figure 3 and Figure 4 ).
[0027] Reference Figure 1 , Figure 3 and Figure 4 The rotating shaft 10 is supported by a radial bearing 24 and a thrust bearing 53 and rotates about axis O. The rotating shaft 10 includes a shaft portion 11, a thrust plate 12, and a plurality of turbine blades 15.
[0028] The shaft portion 11 extends in the thrust direction T. That is, the length direction of the shaft portion 11 is the thrust direction T. The shaft portion 11 includes a first end portion 11a, a second end portion 11b opposite to the first end portion 11a, and a central portion located between the first end portion 11a and the second end portion 11b. The first end portion 11a and the second end portion 11b are the two ends of the shaft portion 11 in the thrust direction T. Hereinafter, the side of the first end portion 11a in the thrust direction T will be referred to as the rear side, and the side of the second end portion 11b will be referred to as the front side. A first through hole 16 extending in the thrust direction T may be provided in the shaft portion 11. When the hydrostatic bearing spindle 1 is used in an electrostatic coating machine, a bell-shaped cup mounting portion 18 may be formed in the second end portion 11b.
[0029] Thrust plate 12 extends from the outer periphery of shaft portion 11 in a radial direction R intersecting the thrust direction T. Thrust plate 12 may, for example, be disposed at the first end 11a of shaft portion 11. Thrust plate 12 includes a thick-walled portion 13 and a thin-walled portion 14. The thick-walled portion 13 is connected to the first end 11a of shaft portion 11. The thickness of the thin-walled portion 14 in the thrust direction T is smaller than the thickness of the thick-walled portion 13 in the thrust direction T. The thin-walled portion 14 is located radially outside the thick-walled portion 13 and surrounds the thick-walled portion 13. In this specification, the side radially away from axis O is referred to as the outer side, and the side radially closer to axis O is referred to as the inner side. The thickness of the portion of thin-walled portion 14 farther from thick-walled portion 13 is, for example, fixed. The thickness of the portion of thin-walled portion 14 closer to thick-walled portion 13 gradually increases as it approaches thick-walled portion 13. The front surface of the portion of thin-walled portion 14 closer to thick-walled portion 13 is, for example, curved. The rear surface of the thick-walled portion 13 and the rear surface of the thin-walled portion 14 are, for example, flush with each other.
[0030] Reference Figure 2 A detection portion 17 is formed on the rear surface of the thrust plate 12 (specifically, the rear surface of the thin-walled portion 14). The detection portion 17 includes multiple regions divided in the rotational direction of the rotation axis 10. These multiple regions include, for example, a first region 17a and a second region 17b. The reflectivity of the first region 17a differs from that of the second region 17b. For example, the reflectivity of the first region 17a is higher than that of the second region 17b.
[0031] Reference Figure 1 , Figure 3 and Figure 4 Multiple turbine blades 15 are disposed on the front surface of the thrust plate 12. Specifically, the multiple turbine blades 15 extend from the front surface of the thin-walled portion 14 of the thrust plate 12 toward the front side in the thrust direction T. The multiple turbine blades 15 are arranged along the outer periphery of the thrust plate 12. The multiple turbine blades 15 are located within the space 35 formed between the thin-walled portion 14 and the rear surface of the radial bearing bushing 21. By receiving turbine gas ejected from the turbine nozzle 62 through the multiple turbine blades 15, the rotating shaft 10 can be rotated.
[0032] Reference Figure 3 and Figure 4 In the case where the hydrostatic bearing spindle 1 is used in an electrostatic coating machine, the bell-shaped cup 19 is mounted on the bell-shaped cup mounting part 18. The bell-shaped cup 19 is, for example, fitted or screwed into the bell-shaped cup mounting part 18. From the paint spray nozzle 78 (see reference...) Figure 4 The coating material is supplied to the bell-shaped cup 19. The bell-shaped cup 19, which rotates at high speed together with the rotating shaft 10, applies centrifugal force to the coating material, thus micronizing it.
[0033] Reference Figure 1 , Figure 3 and Figure 4The housing assembly 20 houses a portion of the shaft portion 11. The housing assembly 20 includes a radial bearing bushing 21 and a housing 25.
[0034] A radial bearing bushing 21 is radially opposed to the shaft portion 11 (more specifically, the central portion of the shaft portion 11) and surrounds a portion of the shaft portion 11. A radial bearing clearance 23 is formed between the shaft portion 11 and the radial bearing bushing 21. In the thrust direction T, the radial bearing bushing 21 is positioned forward of the thrust plate 12. The rear surface of the radial bearing bushing 21 faces the front surface of the thrust plate 12 in the thrust direction T. The radial bearing bushing 21 is provided with a first nozzle 22 for the first bearing gas to flow radially toward the shaft portion 11.
[0035] The housing 25 is disposed on the outer side of the radial bearing bushing 21 in the radial direction R. The housing 25 houses the radial bearing bushing 21. The housing 25 is fixed to the radial bearing bushing 21.
[0036] The cover 27 is disposed on the outer side of the outer shell 25 in the radial direction R. The cover 27 covers the outer shell 25 and houses the outer shell 25.
[0037] The housing 25, radial bearing bushing 21, and cover 27 are configured to supply first bearing gas to the radial bearing clearance 23. Specifically, a first bearing gas supply passage 30 is provided in the housing 25, radial bearing bushing 21, and cover 27. One end of the first bearing gas supply passage 30 is connected to a first bearing gas inlet 31 provided on the outer peripheral surface of the cover 27. The other end of the first bearing gas supply passage 30 is connected to a first nozzle 22 of the radial bearing bushing 21. The diameter of the first nozzle 22 may be smaller than the diameter of the first bearing gas inlet 31, and the first nozzle 22 may be a throttling section. The first bearing gas passes through the first bearing gas inlet 31 and the first bearing gas supply passage 30 and is supplied to the radial bearing clearance 23, thereby forming a radial bearing 24 that supports the shaft 11 in the radial direction R between the shaft 11 and the radial bearing bushing 21.
[0038] The housing 25, radial bearing bushing 21, and cover 27 are configured to exhaust turbine gas supplied to the plurality of turbine blades 15. Specifically, a turbine gas exhaust passage 33 is provided in the housing 25, radial bearing bushing 21, and cover 27. One end of the turbine gas exhaust passage 33 is connected to a turbine gas exhaust port 34 provided on the outer peripheral surface of the cover 27. The turbine gas exhaust port 34 is located rearward of the first bearing gas inlet 31 in the thrust direction T. The other end of the turbine gas exhaust passage 33 communicates with a space 35 formed between the thin-walled portion 14 of the thrust plate 12 and the rear surface of the radial bearing bushing 21.
[0039] Reference Figure 1 , Figure 3 and Figure 4Multiple O-rings 41, 42, 43, and 44 are disposed between the housing 25 and the cover 27, and the housing 25 is elastically supported by the cover 27. The multiple O-rings 41, 42, 43, and 44 are formed, for example, by a perfluoroelastomer, which is a fluororubber. Therefore, when the hydrostatic bearing spindle 1 is used in an electrostatic coating machine, the multiple O-rings 41, 42, 43, and 44 exhibit high resistance to coating solvents.
[0040] O-ring 41 is disposed on the outer side of the thrust plate 12 in the radial direction R. In the thrust direction T, O-ring 41 is disposed at the rearmost position among the plurality of O-rings 41, 42, 43, and 44. In the thrust direction T, O-ring 41 is disposed between the thrust bearing 53 and the center C1 of the radial bearing 24 in the thrust direction T. O-ring 42 is disposed on the outer side of the shaft portion 11 in the radial direction R. In the thrust direction T, O-ring 42 is disposed at a position further forward than O-ring 41. In the thrust direction T, O-ring 42 is disposed between the thrust plate 12 and the center C1 of the radial bearing 24 in the thrust direction T.
[0041] O-ring 43 is positioned radially outward relative to the center of shaft portion 11. In the thrust direction T, O-ring 43 is positioned forward of O-ring 42. In the thrust direction T, at least one of the plurality of O-rings 41, 42, 43, and 44 (e.g., O-ring 43) is positioned between the center C1 of the radial bearing 24 and the center of gravity G1 of the rotating shaft 10 (see reference). Figure 1 and Figure 3 Between. In the thrust direction T, at least one of the plurality of O-rings 41, 42, 43, 44 (e.g., O-ring 43) is positioned at the center C1 of the radial bearing 24 and the center of gravity G2 of the entire rotating shaft 10 and bell cup 19 (see reference). Figure 3 )between.
[0042] O-ring 44 is disposed on the outer side of the shaft portion 11 in the radial direction R relative to the central portion of the shaft portion 11. In the thrust direction T, O-ring 44 is disposed forward of O-ring 43. In the thrust direction T, O-ring 44 is disposed at the most forward position among the plurality of O-rings 41, 42, 43, and 44. In the thrust direction T, at least one O-ring (e.g., O-ring 44) among the plurality of O-rings 41, 42, 43, and 44 is disposed at the center of gravity G1 of the rotating shaft 10 and the center of gravity G3 of the bell cup 19 (see reference). Figure 3 Between. In the thrust direction T, at least one O-ring (e.g., O-ring 44) of the plurality of O-rings 41, 42, 43, 44 is disposed at the center of gravity G2 of the entire rotating shaft 10 and bell cup 19 (see reference). Figure 3 The center of gravity G3 of the bell-shaped cup 19 (refer to) Figure 3 )between.
[0043] Reference Figure 1 , Figure 3 and Figure 4 The thrust bearing bushing 50 is disposed opposite to the thrust plate 12 in the thrust direction T. A thrust bearing clearance 52 is formed between the thrust plate 12 and the thrust bearing bushing 50. In the thrust direction T, the thrust bearing bushing 50 is disposed on the side opposite to the radial bearing bushing 21 side relative to the thrust plate 12. Specifically, in the thrust direction T, the thrust bearing bushing 50 is disposed rearward than the thrust plate 12. The front surface of the thrust bearing bushing 50 is opposite to the rear surface of the thrust plate 12 (specifically, the rear surface of the thick-walled portion 13) in the thrust direction T. The thrust bearing bushing 50 is provided with a second nozzle 51 for the second bearing gas to flow toward the thrust plate 12 in the thrust direction T. The second nozzle 51 can be disposed at the center of the front surface of the thrust bearing bushing 50 in the radial direction R. The center of the front surface of the thrust bearing bushing 50 in the radial direction R is the midpoint between the inner and outer peripheries of the front surface of the thrust bearing bushing 50. The second nozzle 51 can be configured on the center C2 of the thrust bearing 53 in the radial direction R.
[0044] Reference Figure 1 , Figure 3 and Figure 4 The magnet 55 applies a magnetic force to the thrust plate 12, attracting the rotating shaft 10 in the thrust direction T. The magnet 55 is, for example, a permanent magnet. In the thrust direction T, the magnet 55 is positioned relative to the thrust plate 12 on the side opposite to the radial bearing bushing 21 side. Specifically, in the thrust direction T, the magnet 55 is positioned rearward of the thrust plate 12. The magnet 55 is positioned radially inside the thrust bearing bushing 50. The magnet 55 is opposite to the first end 11a of the shaft portion 11. The magnet 55 has a ring shape. The inner diameter of the magnet 55 is approximately equal to the diameter of the first through hole 16. The magnet 55 can be coaxial with the first through hole 16. The front surface of the magnet 55 can be flush with the front surface of the thrust bearing bushing 50, or it can be recessed rearward relative to the front surface of the thrust bearing bushing 50 by a magnet gap g.
[0045] Reference Figure 1 , Figure 3 and Figure 4 The housing 57 houses the thrust bearing bushing 50 and the magnet 55. For example, the front surface of the housing 57 has a first opening and a second opening. The thrust bearing bushing 50 is inserted into the first opening. The magnet 55 is inserted into the second opening. The thrust bearing bushing 50 and the magnet 55 are fixed to the housing 57.
[0046] Reference Figure 1 , Figure 3 and Figure 4The housing 57 may be provided with a second through hole 58 extending in the thrust direction T. The second through hole 58 communicates with the first through hole 16. The second through hole 58 may be coaxial with the first through hole 16. The second through hole 58 is located radially inner than the magnet 55. The diameter of the second through hole 58 is smaller than the inner diameter of the magnet 55. The second through hole 58 is located radially inner than the thrust bearing bushing 50.
[0047] The housing 57 may be provided with a third through hole 59 extending in the thrust direction T. The third through hole 59 is located radially outward from the magnet 55 and the thrust bearing bushing 50. In the thrust direction T, the third through hole 59 is opposite to the detection part 17.
[0048] The housing 57 is configured to supply turbine gas to a plurality of turbine blades 15. Specifically, the housing 57 is provided with a turbine gas supply passage 60. One end of the turbine gas supply passage 60 is connected to a turbine gas inlet 61 disposed on the rear surface of the housing 57. The turbine gas inlet 61 is located radially outward of the second through hole 58, the magnet 55, and the thrust bearing bushing 50. The other end of the turbine gas supply passage 60 is connected to a turbine nozzle 62. The turbine nozzle 62 is configured to eject turbine gas radially inward toward the plurality of turbine blades 15. The turbine gas passes through the turbine gas inlet 61 and the turbine gas supply passage 60 and is supplied to the plurality of turbine blades 15, thereby causing the rotating shaft 10 to rotate.
[0049] Multiple turbine gas supply passages 60 and turbine nozzles 62 can be formed at intervals from each other in the rotation direction of the rotating shaft 10. That is, the turbine gas supply passages 60 and turbine nozzles 62 can be configured to simultaneously supply turbine gas in the same rotation direction relative to multiple turbine blades 15 arranged at arbitrary intervals in the rotation direction of the rotating shaft 10.
[0050] The housing 57 and thrust bearing bushing 50 are configured to supply second bearing gas to the thrust bearing clearance 52. Specifically, a second bearing gas supply passage 65 is provided in the housing 57 and thrust bearing bushing 50. One end of the second bearing gas supply passage 65 is connected to a second bearing gas inlet 66 located on the rear surface of the housing 57. The second bearing gas inlet 66 is located radially outward from the second through hole 58, magnet 55, and thrust bearing bushing 50. The second bearing gas inlet 66 is located radially inward from the turbine gas inlet 61. The other end of the second bearing gas supply passage 65 is connected to a second nozzle 51 of the thrust bearing bushing 50. The diameter of the second nozzle 51 may be smaller than the diameter of the second bearing gas inlet 66, and the second nozzle 51 may be a throttling section.
[0051] The second bearing gas passes through the second bearing gas inlet 66 and the second bearing gas supply path 65 and is supplied to the thrust bearing gap 52, thereby generating a force that presses the thrust plate 12 forward in the thrust direction T. A force that attracts the thrust plate 12 backward in the thrust direction T is generated by the magnet 55. Through the pressing and attracting forces, a thrust bearing 53 supporting the rotating shaft 10 in the thrust direction T is formed between the thrust plate 12 and the thrust bearing bushing 50. The thrust bearing 53 surrounds the first through hole 16. Therefore, the thrust bearing 53 prevents turbine gas from flowing into the first through hole 16 through the thrust bearing gap 52.
[0052] Reference Figure 1 and Figure 3 The distance L from the thrust bearing 53 to the center C1 of the radial bearing 24 in the thrust direction T is larger than the diameter D of the center C2 of the thrust bearing 53 in the radial direction R.
[0053] Reference Figure 4 The spindle retainer 70 houses the hydrostatic bearing spindle 1. Specifically, the spindle retainer 70 has a housing portion 71. The hydrostatic bearing spindle 1 is housed in the housing portion 71. The spindle retainer 70 has a bearing gas supply passage 72, a turbine gas supply passage 73, and a turbine gas exhaust passage 74. When the hydrostatic bearing spindle 1 is housed in the housing portion 71, the bearing gas supply passage 72 is connected to the first bearing gas inlet 31 and the second bearing gas inlet 66, the turbine gas supply passage 73 is connected to the turbine gas inlet 61, and the turbine gas exhaust passage 74 is connected to the turbine gas exhaust port 34. The bearing gas supply passage 72 communicates with the first bearing gas supply passage 30 and the second bearing gas supply passage 65. The turbine gas supply passage 73 communicates with the turbine gas supply passage 60. The turbine gas exhaust passage 74 communicates with the turbine gas exhaust passage 33.
[0054] Reference Figure 4 The spindle retainer 70 may be provided with a paint supply passage 75. When the hydrostatic bearing spindle 1 is housed in the housing 71, the paint supply passage 75 is connected to the paint spray nozzle 78. Paint is supplied to the paint spray nozzle 78 through the paint supply passage 75. The paint spray nozzle 78 sprays the paint supplied from the paint supply passage 75.
[0055] Reference Figure 4The rotation sensor 76 measures the rotational speed of the rotating shaft 10. The rotation sensor 76 is mounted to the spindle retainer 70 via a sensor holder 77. When the hydrostatic bearing spindle 1 is housed in the housing 71, a portion of the rotation sensor 76 is inserted into the third through hole 59. The end of the rotation sensor 76 faces the detected portion 17 of the rotating shaft 10. The rotation sensor 76 is, for example, an optical rotation sensor. The rotation sensor 76 includes: a light source (not shown) capable of emitting light to the detected portion 17; and a photodetector (not shown) capable of detecting reflected light from the detected portion 17. The light source is, for example, a semiconductor laser. The photodetector is, for example, a photodiode. When the rotating shaft 10 rotates one revolution, the photodetector receives, for example, light from the first region 17a of the detected portion 17 (see reference 17a). Figure 2 Bright reflected light from the second region 17b of the detected section 17 (see reference) Figure 2 The dim reflected light from the detected part 17. Therefore, by measuring the number of times the intensity of the reflected light changes from the detected part 17, the rotational speed of the rotating shaft 10 can be determined.
[0056] The operation of the hydrostatic bearing spindle 1 in this embodiment will be explained.
[0057] Bearing gas supplied from a bearing gas supply source (not shown) such as an air compressor flows into bearing gas supply path 72. The bearing gas is divided into first bearing gas and second bearing gas in bearing gas supply path 72.
[0058] The first bearing gas passes through the first bearing gas inlet 31, the first bearing gas supply path 30, and the first nozzle 22, and is supplied to the radial bearing clearance 23. Thus, the radial bearing 24 is formed between the shaft portion 11 and the radial bearing bushing 21.
[0059] The second bearing gas passes through the second bearing gas inlet 66, the second bearing gas supply path 65, and the second nozzle 51, and is supplied to the thrust bearing gap 52. This generates a force that presses the thrust plate 12 forward in the thrust direction T. The magnet 55 generates a force that attracts the thrust plate 12 backward in the thrust direction T. Through the pressing and attracting forces, the thrust bearing 53 is formed between the thrust plate 12 and the thrust bearing bushing 50.
[0060] Turbine gas supplied from a turbine gas supply source (not shown), such as an air compressor, passes through turbine gas supply passage 73, turbine gas inlet 61, and turbine gas supply passage 60, and is supplied to turbine nozzle 62. Turbine gas is ejected from turbine nozzle 62 towards a plurality of turbine blades 15 radially inward. The plurality of turbine blades 15 receive the turbine gas. A rotational torque is imparted to the thrust plate 12. The rotating shaft 10 rotates about axis O. The rotational speed of the rotating shaft 10 can be, for example, tens of thousands of rpm or higher. Therefore, the hydrostatic bearing spindle 1 can be used in an electrostatic coating machine. The turbine gas changes direction due to the curvature of the front surface of the thrust plate 12 and flows into turbine gas exhaust passage 33. The turbine gas passes through turbine gas exhaust passage 33, turbine gas exhaust port 34, and turbine gas exhaust passage 74, and is discharged to the outside of the hydrostatic bearing spindle 1.
[0061] (Variation example)
[0062] Reference Figure 5 In a first variation of the embodiment, the magnet 55 is positioned radially outward from the thrust bearing bushing 50. The magnet 55 is opposite to the thin-walled portion 14 of the thrust plate 12. The inner diameter of the magnet 55 is larger than the diameter of the first through hole 16.
[0063] Reference Figures 6 to 8 In a second variation of the embodiment, the position of the magnet 55 in the thrust direction T is adjustable. That is, the distance g between the front surface of the thrust bearing bushing 50 and the front surface of the magnet 55 in the thrust direction T, i.e., the magnet gap, is adjustable.
[0064] Reference Figure 6 In the first example of the second modification, the magnet 55 is screwed onto the housing 57, and the magnet 55 can move relative to the housing 57 in the thrust direction T. Therefore, the position of the magnet 55 in the thrust direction T can be adjusted, and the magnet gap g can be adjusted.
[0065] Reference Figure 7 In the second example of the second modification, the hydrostatic bearing spindle 1 further includes a spacer 80. The spacer 80 contacts the rear surface of the housing 57 and the magnet 55. By changing the thickness of the spacer 80, the position of the magnet 55 in the thrust direction T can be adjusted, and the magnet gap g can be adjusted. For example, by selecting one spacer 80 from a plurality of spacers 80 having different thicknesses, the thickness of the spacer 80 disposed between the housing 57 and the magnet 55 can be changed.
[0066] Reference Figure 8In the third example of the second modification, the hydrostatic bearing spindle 1 further includes a spacer 80 and a cover 82. The housing 57 includes an inner wall 57w protruding into the second through hole 58 from its inner circumferential surface. The inner wall 57w is formed in the portion of the housing 57 closest to the thrust plate 12. A magnet 55 is disposed on the inner circumferential surface of the second through hole 58. The spacer 80 contacts the rear surface of the inner wall 57w and the front surface of the magnet 55. By changing the thickness of the spacer 80, the position of the magnet 55 in the thrust direction T can be adjusted, and the magnet gap g can be adjusted. The cover 82 is mounted on a portion of the inner circumferential surface of the second through hole 58 and the inner wall 57w. The cover 82 supports the magnet 55 and the spacer 80. The cover 82 has a through hole 83. The through hole 83 communicates with the first through hole 16. The through hole 83 can be coaxial with the first through hole 16. The diameter of the through hole 83 is smaller than the diameter of the second through hole 58. The perforation 83 is located radially inside the second through hole 58.
[0067] Reference Figure 9 In a third variation of the embodiment, the thrust bearing bushing 50 is elastically supported on the housing 57. Specifically, the hydrostatic bearing spindle 1 further includes elastic members 85 and 86. The elastic members 85 and 86 are, for example, O-rings. The elastic members 85 and 86 are disposed between the housing 57 and the thrust bearing bushing 50, elastically supporting the thrust bearing bushing 50 on the housing 57. The elastic member 85 is disposed between the rear surface of the thrust bearing bushing 50 and the housing 57, elastically supporting the thrust bearing bushing 50 on the housing 57 in the thrust direction T. The elastic member 86 is disposed between the outer surface of the thrust bearing bushing 50 and the housing 57, elastically supporting the thrust bearing bushing 50 on the housing 57 in the radial direction R.
[0068] Reference Figures 10 to 19 In the fourth variation of the embodiment, the radial bearing 24 and the thrust bearing 53 can be a hydrostatic bearing with a self-throttling method, a hydrostatic bearing with a porous throttling method, a hydrostatic bearing with an orifice throttling method, or a hydrostatic bearing with a combined throttling method.
[0069] For example, radial bearing 24 and thrust bearing 53 can be Figure 10 and Figure 11 The diagram shows a hydrostatic bearing with a self-throttling mechanism. Specifically, the diameter of the portion of the first nozzle 22 closer to the radial bearing clearance 23 is smaller than the diameter of the portion of the first nozzle 22 farther from the radial bearing clearance 23. Similarly, the diameter of the portion of the second nozzle 51 closer to the thrust bearing clearance 52 is smaller than the diameter of the portion of the second nozzle 51 farther from the thrust bearing clearance 52.
[0070] Radial bearing 24 and thrust bearing 53 can also be Figure 12 and Figure 13The diagram shows a hydrostatic bearing with a porous throttling mechanism. Specifically, the radial bearing bush 21 and the thrust bearing bush 50 are formed of a porous material. A groove 88 may be provided in the portion of the radial bearing bush 21 opposite to the first bearing gas supply path 30. The first bearing gas diffuses through the groove 88 and is uniformly supplied by the porous material as a whole. A groove 89 may be provided in the portion of the thrust bearing bush 50 opposite to the second bearing gas supply path 65. The second bearing gas diffuses through the groove 89 and is uniformly supplied by the porous material as a whole.
[0071] Radial bearing 24 and thrust bearing 53 can also be Figure 14 and Figure 15 The diagram illustrates a hydrostatic bearing with an orifice throttling mechanism. Specifically, the first nozzle 22 includes: an orifice 90 facing the radial bearing clearance 23; and a throttling orifice 91 disposed at the bottom of the orifice 90. The diameter of the throttling orifice 91 is smaller than the diameter of the orifice 90. The second nozzle 51 includes: an orifice 92 facing the thrust bearing clearance 52; and a throttling orifice 93 disposed at the bottom of the orifice 92. The diameter of the throttling orifice 93 is smaller than the diameter of the orifice 92.
[0072] Radial bearing 24 and thrust bearing 53 can also be Figures 16 to 19 The hydrostatic bearing shown is a composite throttling type. A composite throttling type hydrostatic bearing is a hydrostatic bearing that combines a throttling orifice and a groove that overlaps with the throttling orifice.
[0073] Reference Figure 16 The groove 88 can be formed in a manner that overlaps with the throttling orifice 91. For example, the groove 88 can be formed on the inner diameter surface of the radial bearing bushing 21 in a manner that overlaps with the throttling orifice 91. See reference. Figure 17 The groove 89 can be formed in a manner that overlaps with the orifice 93. For example, the groove 89 can be formed on the end face of the thrust bearing bushing 50 in a manner that overlaps with the orifice 93.
[0074] Reference Figure 18 Alternatively, a first compound throttling section can be formed in the first nozzle 22 and the shaft portion 11. For example, a throttling orifice 91 and a groove 94 are formed in the first nozzle 22. A groove 94 is formed on the outer peripheral surface of the shaft portion 11. The groove 94 functions to distribute pressure over a wider range. Therefore, a hydrostatic bearing with a first compound throttling method is formed by the combination of a throttling orifice and a groove in the first nozzle 22 and the shaft portion 11. (See reference...) Figure 19 Alternatively, a second composite throttling section can be formed on the second nozzle 51 and the thrust plate 12. For example, a throttling orifice 93 and a groove 95 are formed on the second nozzle 51. A groove 95 is formed on the rear surface of the thrust plate 12. The groove 95 functions in a way that allows pressure to be distributed over a wider range. Therefore, a hydrostatic bearing with a second composite throttling method is formed by the combination of a throttling orifice and a groove through the second nozzle 51 and the thrust plate 12.
[0075] The effects of the hydrostatic bearing spindle 1 in this embodiment will be explained.
[0076] The hydrostatic bearing spindle 1 of this embodiment includes a rotating shaft 10, a radial bearing bushing 21, a thrust bearing bushing 50, and a magnet 55. The rotating shaft 10 includes: a shaft portion 11 extending in the thrust direction T; a thrust plate 12 extending from the shaft portion 11 in a radial direction R intersecting the thrust direction T; and a turbine blade 15 disposed on the thrust plate 12. The radial bearing bushing 21 is arranged radially opposite to the shaft portion 11. The thrust bearing bushing 50 is arranged radially opposite to the thrust plate 12 in the thrust direction T. The magnet 55 attracts the rotating shaft 10 in the thrust direction T. A radial bearing 24 supporting the shaft portion 11 in the radial direction R is formed between the shaft portion 11 and the radial bearing bushing 21. A thrust bearing 53 supporting the rotating shaft 10 in the thrust direction T is formed between the thrust plate 12 and the thrust bearing bushing 50. The thrust bearing bushing 50 and the magnet 55 are positioned on the opposite side of the thrust plate 12 in the thrust direction T, opposite to the radial bearing bushing 21 side. The distance L from the thrust bearing 53 to the center C1 of the radial bearing 24 in the thrust direction T is greater than the diameter D of the center C2 of the thrust bearing 53 in the radial direction R.
[0077] The thrust bearing bushing 50 and magnet 55 are positioned on the opposite side of the thrust plate 12 in the thrust direction T, opposite to the radial bearing bushing 21 side, thus increasing the area of the radial bearing 24. This improves the load-bearing characteristics of the hydrostatic bearing spindle 1. Furthermore, the distance L in the thrust direction T from the thrust bearing 53 to the center C1 of the radial bearing 24 in the thrust direction T is larger than the diameter D of the center C2 of the thrust bearing 53 in the radial direction R, allowing the radial bearing 24 to be formed longer in the thrust direction T. This further improves the load-bearing characteristics of the hydrostatic bearing spindle 1.
[0078] In the hydrostatic bearing spindle 1 of this embodiment, a through hole (first through hole 16) extending in the thrust direction T is provided in the shaft portion 11 and the thrust plate 12. The thrust bearing 53 surrounds the through hole.
[0079] Therefore, a paint spray nozzle 78 or the like can be arranged inside the through hole (first through hole 16). The hydrostatic bearing spindle 1 can be applied to electrostatic coating machines, etc. Furthermore, since the thrust bearing 53 surrounds the through hole, the thrust bearing 53 can prevent turbine gas from flowing into the first through hole 16 through the thrust bearing clearance 52. When the hydrostatic bearing spindle 1 is used in an electrostatic coating machine, deterioration of coating quality can be prevented.
[0080] In the hydrostatic bearing spindle 1 of this embodiment, the magnet 55 is disposed on the inner side of the thrust bearing bushing 50, which is radially R closer to the inside.
[0081] Therefore, the size of magnet 55 can be reduced. This also reduces the size and cost of hydrostatic bearing spindle 1.
[0082] In the hydrostatic bearing spindle 1 of this embodiment, the magnet 55 is disposed on the outer side of the thrust bearing bushing 50, which is radially R away.
[0083] Therefore, the load-bearing characteristics of the hydrostatic bearing spindle 1 are improved.
[0084] In the hydrostatic bearing spindle 1 of this embodiment, the magnet 55 has a ring shape.
[0085] Therefore, a paint spraying nozzle 78 can be installed inside the through hole of the magnet 55. The hydrostatic bearing spindle 1 can be applied to electrostatic coating machines, etc.
[0086] In the hydrostatic bearing spindle 1 of this embodiment, the position of the magnet 55 in the thrust direction T can be adjusted.
[0087] Therefore, the attractive force of the rotating shaft 10 generated by the magnet 55 can be adjusted. The size of the thrust bearing clearance 52 can be appropriately adjusted. A suitable thrust bearing 53 can be formed that corresponds to the pressure of the second bearing gas supplied to the hydrostatic bearing spindle 1 and the purpose of the hydrostatic bearing spindle 1.
[0088] The hydrostatic bearing spindle 1 of this embodiment also includes a housing 57 for housing the thrust bearing bushing 50 and the magnet 55. The thrust bearing bushing 50 is fixed to the housing 57.
[0089] Therefore, the thrust bearing bushing 50 and the magnet 55 are mechanically protected by the housing 57.
[0090] In this embodiment, the hydrostatic bearing spindle 1 also includes a housing 57 for housing the thrust bearing bushing 50 and the magnet 55. The thrust bearing bushing 50 is elastically supported by the housing 57.
[0091] Therefore, the thrust bearing bushing 50 and the magnet 55 are mechanically protected by the housing 57. Furthermore, since the thrust bearing bushing 50 is elastically supported by the housing 57, it easily follows the attitude changes of the rotating shaft 10. Even when loads caused by gyroscopic torque and vibrations of the rotating shaft are applied to the rotating shaft 10, the rotating shaft 10 can rotate more stably.
[0092] The hydrostatic bearing spindle 1 of this embodiment includes: a housing 25 that houses the radial bearing bushing 21; a cover 27 that covers the housing 25; and a plurality of O-rings 41, 42, 43, and 44. The plurality of O-rings 41, 42, 43, and 44 are disposed between the housing 25 and the cover 27, and the housing 25 is elastically supported by the cover 27. In the thrust direction T, at least one of the plurality of O-rings 41, 42, 43, and 44 (O-ring 43) is disposed between the center C1 of the radial bearing 24 and the center of gravity G1 of the rotating shaft 10.
[0093] Therefore, at least one O-ring (O-ring 43) can be positioned closer to the center of gravity G1 of the rotation axis 10. At least one O-ring can reduce the effects of gyroscopic torque and vibration of the rotation axis 10 on the radial bearing 24 and the thrust bearing 53. The rotation axis 10 can rotate more stably.
[0094] In the hydrostatic bearing spindle 1 of this embodiment, the shaft portion 11 includes: a first end portion 11a on which a thrust plate 12 is provided; and a second end portion 11b on the opposite side of the first end portion 11a. A bell-shaped cup mounting portion 18 is formed at the second end portion 11b.
[0095] Therefore, the load-bearing characteristics of the hydrostatic bearing spindle 1 are improved. This allows the hydrostatic bearing spindle 1 to be used in electrostatic coating machines.
[0096] The hydrostatic bearing spindle 1 of this embodiment also includes a bell cup 19, which is mounted on the bell cup mounting part 18.
[0097] Therefore, the hydrostatic bearing spindle 1 can be applied to an electrostatic coating machine.
[0098] The hydrostatic bearing spindle 1 of this embodiment includes: a housing 25 that houses the radial bearing bushing 21; a cover 27 that covers the housing 25; and a plurality of O-rings 41, 42, 43, and 44. The plurality of O-rings 41, 42, 43, and 44 are disposed between the housing 25 and the cover 27, and the housing 25 is elastically supported by the cover 27. In the thrust direction T, at least one of the plurality of O-rings 41, 42, 43, and 44 (O-ring 43) is disposed between the center C1 of the radial bearing 24 and the center of gravity G2 of the entire rotating shaft 10 and the bell cup 19.
[0099] Therefore, at least one O-ring (O-ring 43) can be positioned closer to the center of gravity G2 of the entire assembly of the rotation shaft 10 and the bell cup 19. With the bell cup 19 mounted on the rotation shaft 10, at least one O-ring can reduce the effects of gyroscopic torque and vibration of the rotation shaft 10 on the radial bearing 24 and the thrust bearing 53. The entire assembly of the rotation shaft 10 and the bell cup 19 can then rotate more stably.
[0100] The hydrostatic bearing spindle 1 of this embodiment includes: a housing 25 that houses a radial bearing bushing 21; a cover 27 that covers the housing 25; and a plurality of O-rings 41, 42, 43, and 44. The plurality of O-rings 41, 42, 43, and 44 are disposed between the housing 25 and the cover 27, and the housing 25 is elastically supported by the cover 27. In the thrust direction T, at least one of the plurality of O-rings 41, 42, 43, and 44 (O-ring 44) is disposed between the center of gravity G1 of the rotating shaft 10 and the center of gravity G3 of the bell cup 19.
[0101] Therefore, even if a vibration load is applied to the bell-shaped cup mounting portion 18 side (second end 11b side) of the hydrostatic bearing spindle 1, at least one O-ring (O-ring 44) is sufficient to reduce the impact of the load on the radial bearing 24 and the thrust bearing 53. The rotating shaft 10 and the bell-shaped cup 19 as a whole can rotate more stably.
[0102] In the hydrostatic bearing spindle 1 of this embodiment, the radial bearing 24 and the thrust bearing 53 are hydrostatic bearings with self-throttling, hydrostatic bearings with porous throttling, hydrostatic bearings with orifice throttling, or hydrostatic bearings with combined throttling.
[0103] Therefore, the load-bearing characteristics of the hydrostatic bearing spindle 1 are improved.
[0104] It should be considered that the embodiments and variations thereof disclosed herein are illustrative rather than restrictive in all respects. The scope of this disclosure is defined by the claims rather than the foregoing description and is intended to include all modifications within the meaning and scope equivalent to the claims.
Claims
1. A hydrostatic bearing spindle, characterized in that, have: A rotating shaft includes a shaft portion, a thrust plate, and turbine blades. The shaft portion extends in the thrust direction, the thrust plate extends radially from the shaft portion in a direction intersecting the thrust direction, and the turbine blades are disposed on the thrust plate. A radial bearing bushing, the radial bearing bushing being disposed radially opposite to the shaft portion; A thrust bearing bushing, the thrust bearing bushing being disposed opposite to the thrust plate in the thrust direction; and A magnet that attracts the rotating shaft in the direction of the thrust. A radial bearing supporting the shaft portion in the radial direction is formed between the shaft portion and the radial bearing bushing. A thrust bearing supporting the rotating shaft in the thrust direction is formed between the thrust plate and the thrust bearing bushing. The thrust bearing bushing and the magnet are positioned on the opposite side of the radial bearing bushing side relative to the thrust plate in the thrust direction. The distance from the thrust bearing to the center of the radial bearing in the thrust direction is greater than the diameter of the center of the thrust bearing in the radial direction.
2. The hydrostatic bearing spindle according to claim 1, characterized in that, A through hole extending in the thrust direction is provided in the shaft portion and the thrust plate. The thrust bearing surrounds the through hole.
3. The hydrostatic bearing spindle according to claim 1 or 2, characterized in that, The magnet is positioned radially inside the thrust bearing bushing.
4. The hydrostatic bearing spindle according to claim 1 or 2, characterized in that, The magnet is positioned radially outward from the thrust bearing bushing.
5. The hydrostatic bearing spindle according to claim 1 or 2, characterized in that, The magnet has a ring shape.
6. The hydrostatic bearing spindle according to claim 1 or 2, characterized in that, The position of the magnet in the direction of the thrust can be adjusted.
7. The hydrostatic bearing spindle according to claim 1 or 2, characterized in that, It also includes a housing for accommodating the thrust bearing bushing and the magnet. The thrust bearing bushing is fixed to the housing.
8. The hydrostatic bearing spindle according to claim 1 or 2, characterized in that, It also includes a housing for accommodating the thrust bearing bushing and the magnet. The thrust bearing bushing is elastically supported by the housing.
9. The hydrostatic bearing spindle according to claim 1 or 2, characterized in that, have: A housing that houses the radial bearing bushing; A cover, the cover covering the outer shell; and Multiple O-rings, The plurality of O-rings are disposed between the outer shell and the cover, and elastically support the outer shell on the cover. In the thrust direction, at least one of the plurality of O-rings is disposed between the center of the radial bearing and the center of gravity of the rotating shaft.
10. The hydrostatic bearing spindle according to claim 1 or 2, characterized in that, The shaft portion includes: a first end portion on which the thrust plate is disposed; and a second end portion on the opposite side of the first end portion. A bell-shaped cup mounting portion is formed at the second end.
11. The hydrostatic bearing spindle according to claim 10, characterized in that, It also includes a bell-shaped cup, which is mounted on the bell-shaped cup mounting part.
12. The hydrostatic bearing spindle according to claim 11, characterized in that, have: A housing that houses the radial bearing bushing; A cover, the cover covering the outer shell; and Multiple O-rings, The plurality of O-rings are disposed between the outer shell and the cover, and elastically support the outer shell on the cover. In the thrust direction, at least one of the plurality of O-rings is disposed between the center of the radial bearing and the center of gravity of the entire rotating shaft and the bell cup.
13. The hydrostatic bearing spindle according to claim 11, characterized in that, have: A housing that houses the radial bearing bushing; A cover, the cover covering the outer shell; and Multiple O-rings, The plurality of O-rings are disposed between the outer shell and the cover, and elastically support the outer shell on the cover. In the thrust direction, at least one of the plurality of O-rings is positioned between the center of gravity of the rotating shaft and the center of gravity of the bell-shaped cup.
14. The hydrostatic bearing spindle according to claim 1 or 2, characterized in that, The radial bearing and the thrust bearing are hydrostatic bearings with self-throttling, hydrostatic bearings with porous throttling, hydrostatic bearings with orifice throttling, or hydrostatic bearings with combined throttling.