Hydrostatic spindle

Abstract

A hydrostatic spindle (1) comprises: a shaft (10); a radial bearing sleeve (21); a thrust bearing sleeve (50); and a magnet (55). The shaft (10) comprises a shaft section (11) extending in a compression direction (T) and a thrust washer (12) extending from the shaft section (11) in a radial direction (R). The thrust bearing sleeve (50) and the magnet (55) are arranged opposite the side of the radial bearing sleeve (21) with respect to the thrust washer (12) in the compression direction (T).

Description

CROSS-REFERENCE TO RELATED REGISTRATIONS

[0001] This non-provisional application is based on Japanese patent application No. 2024-168132, which was filed with the Japanese Patent Office on September 27, 2024, and the contents of which are hereby incorporated in full by reference. BACKGROUND OF THE INVENTION Area of ​​the invention

[0002] The present disclosure relates to a hydrostatic spindle. Description of the state of the art

[0003] Japanese patent no. 6935766 and Japanese patent no. 7035594 each disclose a spindle device. BRIEF SUMMARY OF THE INVENTION

[0004] When the position of a spindle device changes and the angle of a high-speed rotating shaft changes, a gyroscopic moment is generated in the shaft. If the shaft has uneven weight in its circumferential direction, it may also vibrate as it rotates. Thus, a load caused by the gyroscopic moment and the shaft vibration acts upon the shaft. The present disclosure was conceived with regard to the problem described above, one objective being to provide a hydrostatic spindle with improved load-resistance characteristics.

[0005] A hydrostatic spindle according to the present disclosure comprises: a shaft; a radial bearing sleeve; a thrust bearing sleeve; and a magnet. The shaft comprises a shaft section extending in a thrust direction, a thrust disk extending from the shaft section in a radial direction intersecting the thrust direction, and a turbine blade provided on the thrust disk. The radial bearing sleeve is arranged so that it faces the shaft section in the radial direction. The thrust bearing sleeve is arranged so that it faces the thrust disk in the thrust direction. The magnet attracts the shaft in the thrust direction. A radial bearing is formed between the shaft section and the radial bearing sleeve, supporting the shaft section in the radial direction. A thrust bearing is formed between the thrust disk and the thrust bearing sleeve, supporting the shaft in the thrust direction.The thrust bearing sleeve and the magnet are arranged oppositely to the thrust washer in the direction of pressure on the radial bearing sleeve side. The distance in the direction of pressure from the thrust bearing to a center of the radial bearing is smaller than the diameter of a center of the thrust bearing in the radial direction.

[0006] The aforementioned and other tasks, features, aspects and advantages of the present disclosure will become clearer from the detailed description of the present disclosure below in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a schematic cross-sectional view of a hydrostatic spindle according to one embodiment. Fig. Figure 2 is a rear view of a shaft contained in the hydrostatic spindle according to the embodiment. Fig. Figure 3 is a schematic cross-sectional view of the hydrostatic spindle according to the embodiment with a bell. Fig. Figure 4 is a schematic cross-sectional view of the hydrostatic spindle according to the embodiment, which is mounted in a spindle holder. Fig. Figure 5 is a schematic cross-sectional view of a hydrostatic spindle according to a first further development of the embodiment. Fig. Figure 6 is a schematic, partially enlarged cross-sectional view of a hydrostatic spindle according to a first example of a second further development of the embodiment. Fig. Figure 7 is a schematic, partially enlarged cross-sectional view of a hydrostatic spindle according to a second example of the second further development of the embodiment. Fig. Figure 8 is a schematic, partially enlarged cross-sectional view of a hydrostatic spindle according to a third example of the second further development of the embodiment. Fig. Figure 9 is a schematic, partially enlarged cross-sectional view of a hydrostatic spindle according to a third further development of the embodiment. Fig. Figure 10 is a schematic, partially enlarged cross-sectional view of a radial bearing of a hydrostatic spindle according to a first example of a fourth further development of the embodiment. Fig. Figure 11 is a schematic, partially enlarged cross-sectional view of a thrust bearing of the hydrostatic spindle according to the first example of the fourth further development of the embodiment. Fig. Figure 12 is a schematic, partially enlarged cross-sectional view of a radial bearing of a hydrostatic spindle according to a second example of the fourth further development of the embodiment. Fig. Figure 13 is a schematic, partially enlarged cross-sectional view of a thrust bearing of the hydrostatic spindle according to the second example of the fourth further development of the embodiment. Fig. Figure 14 is a schematic, partially enlarged cross-sectional view of a radial bearing of a hydrostatic spindle according to a third example of the fourth further development of the embodiment. Fig. Figure 15 is a schematic, partially enlarged cross-sectional view of a thrust bearing of the hydrostatic spindle according to the third example of the fourth further development of the embodiment. Fig. Figure 16 is a schematic, partially enlarged cross-sectional view of a radial bearing of a hydrostatic spindle according to a fourth example of the fourth further development of the embodiment. Fig. Figure 17 is a schematic, partially enlarged cross-sectional view of a thrust bearing of the hydrostatic spindle according to the fourth example of the fourth further development of the embodiment. Fig. Figure 18 is a schematic, partially enlarged cross-sectional view of a radial bearing of a hydrostatic spindle according to a fifth example of the fourth further development of the embodiment. Fig. Figure 19 is a schematic, partially enlarged cross-sectional view of a thrust bearing of the hydrostatic spindle according to the fifth example of the fourth further development of the embodiment. DESCRIPTION OF PREFERRED EXECUTION FORMS

[0007] Details of one embodiment of the present disclosure are described with reference to the drawings. In the drawings below, identical or corresponding parts are designated by the same reference numerals, so that repeated description is unnecessary. At least some of the configurations of the embodiment described below can be combined as desired.

[0008] With reference to Fig. Figures 1 to 4 describe a hydrostatic spindle 1 according to one embodiment. The hydrostatic spindle 1 is used, for example, in an electrostatic coating machine or the like. The hydrostatic spindle 1 comprises a shaft 10, a housing assembly 20, a cover 27, a plurality of O-rings 41, 42, 43 and 44, a thrust bearing sleeve 50, a magnet 55 and a casing 57. The hydrostatic spindle 1 may further comprise a bell 19 (see Figure 1). Fig. 3 and Fig. 4).

[0009] According to Fig. 1, Fig. 3 and Fig. 4 The shaft 10 is supported by a radial bearing 24 and a thrust bearing 53 and rotates about an axis O. The shaft 10 comprises a shaft section 11, a thrust washer 12 and a plurality of turbine blades 15.

[0010] The shaft section 11 extends in a pressure direction T. That is, the direction of a longer side of the shaft section 11 is the pressure direction T. The shaft section 11 comprises a first end section 11a, a second end section 11b opposite the first end section 11a, and a middle section located between the second end section 11b and the first end section 11a. The first end section 11a and the second end section 11b are both end sections of the shaft section 11 in the pressure direction T. Hereinafter, one side of the first end section 11a in the pressure direction T is referred to as the rear side, and one side of the second end section 11b in the pressure direction T is referred to as the front side. The shaft section 11 may be provided with a first through-bore 16 extending in the pressure direction T.If the hydrostatic spindle 1 is used in an electrostatic coating machine, a bell mounting section 18 can be formed in the second end section 11b.

[0011] The pressure disk 12 extends from an outer circumferential surface of the shaft section 11 in a radial direction R that intersects the pressure direction T. The pressure disk 12 is provided, for example, in the first end section 11a of the shaft section 11. The pressure disk 12 comprises a thick section 13 and a thin section 14. The thick section 13 is connected to the first end section 11a of the shaft section 11. The thickness of the thin section 14 in the pressure direction T is less than the thickness of the thick section 13 in the pressure direction T. The thin section 14 is located radially outside the thick section 13 in the radial direction R and surrounds the thick section 13. In this description, a side that is far from the axis O in the radial direction R is referred to as the outside, and a side that is close to the axis O in the radial direction R is referred to as the inside.For example, the thickness of a section of the thin section 14 located away from the thick section 13 is constant. The thickness of a section of the thin section 14 located near the thick section 13 gradually increases towards the thick section 13. For example, the front face of the section of the thin section 14 located near the thick section 13 is a curved surface. For example, the back face of the thick section 13 and the back face of the thin section 14 are flush with each other.

[0012] According to Fig. 2 A section 17 to be detected is formed on the back side of the pressure disk 12 (in particular, the back side of the thin section 14). The section 17 to be detected comprises a plurality of regions subdivided in a direction of rotation of the shaft 10. The plurality of regions includes, for example, a first region 17a and a second region 17b. The reflectance of the first region 17a differs from the reflectance of the second region 17b. For example, the reflectance of the first region 17a is higher than the reflectance of the second region 17b.

[0013] According to Fig. 1, Fig. 3 and Fig. 4 The plurality of turbine blades 15 is provided on a front face of the pressure disk 12. Specifically, the plurality of turbine blades 15 extends forward in the pressure direction T from the front face of the thin section 14 of the pressure disk 12. The plurality of turbine blades 15 is arranged along an outer circumference of the pressure disk 12. The plurality of turbine blades 15 is located in a space 35 formed between the thin section 14 and the rear face of a radial bearing sleeve 21. When the plurality of turbine blades 15 receives turbine gas exiting from a turbine nozzle 62, the shaft 10 can rotate.

[0014] When the hydrostatic spindle 1 is used in an electrostatic coating machine, according to Fig. 3 and Fig. 4. Bell 19 is attached to the bell mounting section 18. Bell 19 is, for example, placed or screwed onto bell mounting section 18. A coating material is applied to bell 19 from a coating material injection nozzle 78 (see Fig. 4) supplied. The bell 19, which rotates at high speed together with the shaft 10, causes the centrifugal force to act on the coating material, thereby bringing the coating material into microparticle form.

[0015] According to Fig. 1, Fig. 3 and Fig. 4 The housing assembly 20 accommodates part of the shaft section 11. The housing assembly 20 comprises a radial bearing sleeve 21 and a housing 25.

[0016] The radial bearing sleeve 21 is arranged such that it faces the shaft section 11 (more precisely, the central section of the shaft section 11) in the radial direction R and surrounds a portion of the shaft section 11. A radial bearing gap 23 is formed between the shaft section 11 and the radial bearing sleeve 21. In the pressure direction T, the radial bearing sleeve 21 is positioned on its front side relative to the pressure plate 12. The rear side of the radial bearing sleeve 21 faces the front side of the pressure plate 12 in the pressure direction T. The radial bearing sleeve 21 is provided with a first nozzle 22 through which a first bearing gas flows out in the radial direction R towards the shaft section 11.

[0017] The housing 25 is arranged radially R away from the radial bearing sleeve 21. The housing 25 accommodates the radial bearing sleeve 21. The housing 25 is attached to the radial bearing sleeve 21.

[0018] The cover 27 is arranged radially R to the outside of the housing 25. The cover 27 covers and receives the housing 25.

[0019] The housing 25, the radial bearing sleeve 21, and the cover 27 are designed such that the first bearing gas can be supplied to the radial bearing gap 23. In particular, the housing 25, the radial bearing sleeve 21, and the cover 27 are provided with a first bearing gas supply channel 30. One end of the first bearing gas supply channel 30 is connected to a first bearing gas inlet 31, which is provided on an outer circumferential surface of the cover 27. The other end of the first bearing gas supply channel 30 is connected to the first nozzle 22 of the radial bearing sleeve 21. The diameter of the first nozzle 22 can be smaller than the diameter of the first bearing gas inlet 31, and the first nozzle 22 can be a throttle.The first bearing gas is supplied to the radial bearing gap 23 through the first bearing gas inlet 31 and the first bearing gas supply channel 30, thereby forming the radial bearing 24 between the shaft section 11 and the radial bearing sleeve 21, which supports the shaft section 11 in the radial direction R.

[0020] The housing 25, the radial bearing sleeve 21, and the cover 27 are designed to allow the discharge of turbine gas supplied to the plurality of turbine blades 15. Specifically, the housing 25, the radial bearing sleeve 21, and the cover 27 are provided with a turbine gas discharge channel 33. One end of the turbine gas discharge channel 33 is connected to a turbine gas outlet 34 located on the outer circumferential surface of the cover 27. The turbine gas outlet 34 is positioned in the pressure direction T relative to the first bearing gas inlet 31 on the rear side. The other end of the turbine gas discharge channel 33 is connected to the space 35 formed between the thin section 14 of the thrust washer 12 and the rear face of the radial bearing sleeve 21.

[0021] According to Fig. 1, Fig. 3 and Fig. In Figure 4, a multitude of O-rings 41, 42, 43, and 44 are arranged between the housing 25 and the cover 27, providing elastic support for the housing 25 relative to the cover 27. The multitude of O-rings 41, 42, 43, and 44 are made, for example, of perfluoroelastomer, a fluorine-based rubber. Therefore, when the hydrostatic spindle 1 is used in an electrostatic coating machine, the multitude of O-rings 41, 42, 43, and 44 exhibits high resistance to the solvents in the coating material.

[0022] The O-ring 41 is arranged radially R on the outside relative to the pressure plate 12. In the pressure direction T, the O-ring 41 is located on the rearmost side of the plurality of O-rings 41, 42, 43, and 44. In the pressure direction T, the O-ring 41 is located between the thrust bearing 53 and a center point C1 of the radial bearing 24 in the pressure direction T. The O-ring 42 is arranged radially R on the outside relative to the central section of the shaft section 11. In the pressure direction T, the O-ring 42 is located on the front side relative to the O-ring 41. In the pressure direction T, the O-ring 42 is located between the pressure plate 12 and the center point C1 of the radial bearing 24 in the pressure direction T.

[0023] The O-ring 43 is arranged radially R on the outside relative to the central section of the shaft section 11. In the compression direction T, the O-ring 43 is arranged on the front side relative to the O-ring 42. In the compression direction T, at least one O-ring (e.g., the O-ring 43) of the plurality of O-rings 41, 42, 43, and 44 is located between the center C1 of the radial bearing 24 in the compression direction T and a center of gravity G1 (see figure). Fig. 1 and Fig. 3) of the shaft 10. In the pressure direction T, at least one O-ring (e.g., O-ring 43) of the plurality of O-rings 41, 42, 43, and 44 is located between the center C1 of the radial bearing 24 and a center of gravity G2 (see Fig. 3) the entirety of wave 10 and bell 19 arranged.

[0024] The O-ring 44 is arranged radially R on the outside relative to the central section of the shaft section 11. In the pressure direction T, the O-ring 44 is arranged relative to the O-ring 43 on the front side. In the pressure direction T, the O-ring 44 is arranged on the foremost side of the plurality of O-rings 41, 42, 43, and 44. In the pressure direction T, at least one O-ring (e.g., the O-ring 44) of the plurality of O-rings 41, 42, 43, and 44 is located between the center of gravity G1 of the shaft 10 and a center of gravity G3 (see figure). Fig. 3) of the bell 19. In the pressure direction T, at least one O-ring (e.g., O-ring 44) of the plurality of O-rings 41, 42, 43, and 44 is arranged between the center of gravity G2 (see Fig. 3) the entirety of wave 10 and bell 19 and the center of gravity G3 (see Fig. 3) arranged for bell 19.

[0025] According to Fig. 1, Fig. 3 and Fig. In section 4, the thrust bearing sleeve 50 is arranged such that it faces the thrust plate 12 in the pressure direction T. A thrust bearing gap 52 is formed between the thrust plate 12 and the thrust bearing sleeve 50. In the pressure direction T, the thrust bearing sleeve 50 is opposite the side of the radial bearing sleeve 21 with respect to the thrust plate 12. In particular, the thrust bearing sleeve 50 is arranged on its rear side relative to the thrust plate 12 in the pressure direction T. A front face of the thrust bearing sleeve 50 faces the rear face of the thrust plate 12 (in particular, the rear face of the thick section 13) in the pressure direction T. The thrust bearing sleeve 50 is provided with a second nozzle 51 through which a second bearing gas flows in the pressure direction T towards the thrust plate 12. The second nozzle 51 can be arranged in the radial direction R at the center of the front face of the thrust bearing sleeve 50.The center of the front face of the thrust bearing sleeve 50 in radial direction R is an intermediate section between an inner circumferential edge and an outer circumferential edge of the front face of the thrust bearing sleeve 50. The second nozzle 51 can be arranged in radial direction R at a center C2 of the thrust bearing 53.

[0026] According to Fig. 1, Fig. 3 and Fig. 4. The magnet 55 exerts a magnetic force on the pressure plate 12 and attracts the shaft 10 in the pressure direction T. The magnet 55 is, for example, a permanent magnet. The magnet 55 is arranged opposite the side of the radial bearing sleeve 21 with respect to the pressure plate 12 in the pressure direction T. In particular, the magnet 55 is arranged on the rear side relative to the pressure plate 12 in the pressure direction T. The magnet 55 is arranged radially R inside the pressure bearing sleeve 50. The magnet 55 is opposite the first end section 11a of the shaft section 11. The magnet 55 has a ring shape. An inner diameter of the magnet 55 can be substantially equal to a diameter of the first through-bore 16. The magnet 55 can be coaxial with the first through-bore 16. The front of the magnet 55 can be flush with the front of the thrust bearing sleeve 50 or offset to the rear by a magnetic gap g from the front of the thrust bearing sleeve 50.

[0027] According to Fig. 1, Fig. 3 and Fig. 4. The casing 57 accommodates the thrust bearing sleeve 50 and the magnet 55. One front face of the casing 57 is provided with, for example, a first and a second opening. The thrust bearing sleeve 50 is inserted into the first opening. The magnet 55 is inserted into the second opening. The thrust bearing sleeve 50 and the magnet 55 are attached to the casing 57.

[0028] According to Fig. 1, Fig. 3 and Fig. 4. The shell 57 can be provided with a second through-hole 58 extending in the pressure direction T. The second through-hole 58 is connected to the first through-hole 16.

[0029] The second through-hole 58 can be coaxial with the first through-hole 16. The second through-hole 58 is located radially R inside 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 R inside the thrust bearing sleeve 50.

[0030] The casing 57 can be provided with a third through-hole 59 extending in the pressure direction T. The third through-hole 59 is located radially R to the outside of the magnet 55 and the thrust bearing sleeve 50. In the pressure direction T, the third through-hole 59 is opposite the section 17 to be captured.

[0031] The casing 57 is designed to supply turbine gas to the plurality of turbine blades 15. In particular, the casing 57 is provided with a turbine gas supply channel 60. One end of the turbine gas supply channel 60 is connected to a turbine gas inlet 61, which is provided in a rear face of the casing 57. The turbine gas inlet 61 is arranged radially R to the outside relative to the second through-bore 58, the magnet 55, and the thrust bearing sleeve 50. The other end of the turbine gas supply channel 60 is connected to the turbine nozzle 62. The turbine nozzle 62 is designed to expel the turbine gas radially R inwards towards the plurality of turbine blades 15. When the turbine gas is supplied to the multitude of turbine blades 15 through the turbine gas inlet 61 and the turbine gas supply channel 60, the shaft 10 rotates.

[0032] A plurality of turbine gas supply channels 60 and a plurality of turbine nozzles 62 can be configured such that they are spaced apart from one another in the direction of rotation of the shaft 10. That is, the turbine gas supply channels 60 and the turbine nozzles 62 can be arranged such that the turbine gas can be supplied simultaneously in the same direction of rotation to the plurality of turbine blades 15, which are arranged in the direction of rotation of the shaft 10 with a suitable intermediate spacing.

[0033] The shell 57 and the thrust bearing sleeve 50 are designed such that a second bearing gas can be supplied to the thrust bearing gap 52. In particular, the shell 57 and the thrust bearing sleeve 50 are provided with a second bearing gas supply channel 65. One end of the second bearing gas supply channel 65 is connected to a second bearing gas inlet 66, which is provided in the rear of the shell 57. The second bearing gas inlet 66 is arranged radially R externally relative to the second through-bore 58, the magnet 55, and the thrust bearing sleeve 50. The second bearing gas inlet 66 is arranged radially R internally relative to the turbine gas inlet 61. The other end of the second bearing gas supply channel 65 is connected to the second nozzle 51 of the thrust bearing sleeve 50. The diameter of the second nozzle 51 can be smaller than the diameter of the second bearing gas inlet 66, and the second nozzle 51 can be a throttle.

[0034] When the second bearing gas is supplied through the second bearing gas inlet 66 and the second bearing gas supply channel 65 into the thrust bearing gap 52, a force is generated that pushes the thrust disk 12 forward in the pressure direction T. The magnet 55 generates the force that attracts the thrust disk 12 backward in the pressure direction T. The pressure force and the attractive force form the thrust bearing 53 between the thrust disk 12 and the thrust bearing sleeve 50, supporting the shaft 10 in the pressure direction T. The thrust bearing 53 surrounds the first through-bore 16. Therefore, the thrust bearing 53 prevents the turbine gas from flowing through the thrust bearing gap 52 into the first through-bore 16.

[0035] According to Fig. 1 and Fig. 3 is a distance L in the pressure direction T from the thrust bearing 53 to the center C1 of the radial bearing 24 in the pressure direction T smaller than a diameter D of the center C2 of the thrust bearing 53 in the radial direction R.

[0036] According to Fig. Figure 4 shows a spindle holder 70, which accommodates the hydrostatic spindle 1. Specifically, the spindle holder 70 is provided with a receiving section 71. The hydrostatic spindle 1 is received in the receiving section 71. The spindle holder 70 is provided with a bearing gas supply channel 72, a turbine gas supply channel 73, and a turbine gas discharge channel 74. When the hydrostatic spindle 1 is received in the receiving section 71, the bearing gas supply channel 72 is connected to the first bearing gas inlet 31 and the second bearing gas inlet 66, the turbine gas supply channel 73 is connected to the turbine gas inlet 61, and the turbine gas discharge channel 74 is connected to the turbine gas outlet 34. Storage gas supply channel 72 is connected to the first storage gas supply channel 30 and the second storage gas supply channel 65. Turbine gas supply channel 73 is connected to turbine gas supply channel 60.The turbine gas discharge channel 74 is connected to the turbine gas discharge channel 33.

[0037] According to Fig. 4. The spindle holder 70 can be provided with a coating material supply channel 75. When the hydrostatic spindle 1 is mounted in the receiving section 71, the coating material supply channel 75 is connected to the coating material injection nozzle 78. The coating material is supplied to the coating material injection nozzle 78 through the coating material supply channel 75. The coating material injection nozzle 78 injects the coating material supplied from the coating material supply channel 75.

[0038] According to Fig. 4. A rotation sensor 76 can measure the rotational speed of the shaft 10. The rotation sensor 76 is attached to the spindle holder 70 by a sensor holder 77. When the hydrostatic spindle 1 is received in the receiving section 71, part of the rotation sensor 76 is inserted into the third through-hole 59. One end of the rotation sensor 76 faces the section 17 of the shaft 10 to be detected. The rotation sensor 76 is, for example, an optical rotation sensor 76. The rotation sensor 76 includes a light source (not shown) that can emit light onto the section 17 to be detected and a photodetector (not shown) that can detect light reflected from the section 17 to be detected. The light source is, for example, a semiconductor laser. The photodetector is, for example, a photodiode.When wave 10 rotates once, the photodetector receives, for example, bright reflected light from the first area 17a (see . Fig. 2) of the section to be captured 17 and dark reflected light from the second area 17b (see Fig. 2) of the section 17 to be detected. By measuring the number of intensity changes of the light reflected from the section 17 to be detected, the rotational speed of the shaft 10 can therefore be measured.

[0039] The following describes the operation of the hydrostatic spindle 1 according to the present embodiment.

[0040] A storage gas supplied from a storage gas source (not shown), for example an air compressor, flows into the storage gas supply channel 72. The storage gas is separated in the storage gas supply channel 72 into a first storage gas and a second storage gas.

[0041] The first bearing gas is supplied to the radial bearing gap 23 through the first bearing gas inlet 31, the first bearing gas supply channel 30, and the first nozzle 22. In this way, the radial bearing 24 is formed between the shaft section 11 and the radial bearing sleeve 21.

[0042] The second bearing gas is supplied to the thrust bearing gap 52 via the second bearing gas inlet 66, the second bearing gas supply channel 65, and the second nozzle 51. This generates the force that pushes the pressure disk 12 forward in the pressure direction T. The magnet 55 generates the force that attracts the pressure disk 12 backward in the pressure direction T. The thrust force and the attractive force form the thrust bearing 53 between the pressure disk 12 and the thrust bearing sleeve 50.

[0043] Turbine gas supplied from a turbine gas source (not shown), for example, an air compressor, is fed to the turbine nozzle 62 via the turbine gas supply channel 73, the turbine gas inlet 61, and the turbine gas supply channel 60. The turbine gas is expelled from the turbine nozzle 62 radially inwards in the direction R towards the plurality of turbine blades 15. The plurality of turbine blades 15 receives the turbine gas. The torque is transmitted to the thrust disk 12. The shaft 10 rotates about the axis O. The rotational speed of the shaft 10 can be set, for example, to several tens of thousands of revolutions per minute or more. Therefore, the hydrostatic spindle 1 can be used in an electrostatic coating machine. The direction of the turbine gas is changed at the curved front face of the thrust disk 12, and the turbine gas flows into the turbine gas discharge channel 33.The turbine gas is discharged outside the hydrostatic spindle 1 through the turbine gas discharge channel 33, the turbine gas outlet 34 and the turbine gas discharge channel 74. (Further training)

[0044] According to Fig. In a first further development of the embodiment, the magnet 55 is arranged radially R to the outside of the thrust bearing sleeve 50. The magnet 55 is opposite the thin section 14 of the pressure plate 12. The inner diameter of the magnet 55 is larger than the diameter of the first through-hole 16.

[0045] According to Fig. In a second further development of the embodiment, the position of the magnet 55 in the pressure direction T is adjustable, as shown in figures 6 to 8. That is, the magnetic gap g, which represents a distance between the front of the thrust bearing sleeve 50 and the front of the magnet 55 in the pressure direction T, is adjustable.

[0046] According to Fig. In a first example of the second further development, magnet 55 is screwed to the casing 57, and magnet 55 is movable in the pressure direction T with respect to the casing 57. Therefore, the position of magnet 55 in the pressure direction T is adjustable, and the magnetic gap g is adjustable.

[0047] According to Fig. In a second example of the second embodiment, the hydrostatic spindle 1 further comprises a spacer 80. The spacer 80 is in contact with the casing 57 and a rear side of the magnet 55. By changing the thickness of the spacer 80, the position of the magnet 55 in the pressure direction T can be adjusted, and the magnetic gap g can be set. For example, by selecting a spacer 80 from a variety of spacers 80 with different thicknesses, the thickness of the spacer 80 arranged between the casing 57 and the magnet 55 can be changed.

[0048] According to Fig. In a third example of the second embodiment, the hydrostatic spindle 1 further comprises the spacer 80 and a cover 82. The casing 57 includes an inner wall 57w that projects from an inner circumferential surface of the second through-bore 58 into the interior of the second through-bore 58. The inner wall 57w is formed on a section of the casing 57 located near the pressure plate 12. The magnet 55 is arranged on the inner circumferential surface of the second through-bore 58. The spacer 80 is in contact with a rear side of the inner wall 57w and the front side of the magnet 55. By changing the thickness of the spacer 80, the position of the magnet 55 in the pressure direction T can be adjusted, and the magnetic gap g can be adjusted. The cover 82 is attached to a portion of the inner circumferential surface that defines the second through-bore 58 and the inner wall 57w. The lid 82 supports the magnet 55 and the spacer 80.The cover 82 is provided with a through-hole 83. The through-hole 83 is connected to 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 through-hole 83 is located radially R inside the second through-hole 58.

[0049] According to Fig. In a third embodiment, the thrust bearing sleeve 50 is elastically supported by the casing 57. The hydrostatic spindle 1 further comprises elastic elements 85 and 86. Each of the elastic elements 85 and 86 is, for example, an O-ring. The elastic elements 85 and 86 are arranged between the casing 57 and the thrust bearing sleeve 50 and elastically support the thrust bearing sleeve 50 with respect to the casing 57. The elastic element 85 is arranged between a rear surface of the thrust bearing sleeve 50 and the casing 57 and elastically supports the thrust bearing sleeve 50 with respect to the casing 57 in the compressive direction T. The elastic element 86 is arranged between an outer surface of the thrust bearing sleeve 50 and the casing 57 and elastically supports the thrust bearing sleeve 50 with respect to the casing 57 in the radial direction R.

[0050] According to Fig. In a fourth further development of the embodiment, the radial bearing 24 and the thrust bearing 53 can each be a hydrostatic bearing of the type with integrated throttle, a hydrostatic bearing of the type with porous throttle, a hydrostatic bearing of the type with opening throttle or a hydrostatic bearing of the type with compound throttle.

[0051] For example, the radial bearing 24 and the thrust bearing 53 can each be a hydrostatic bearing of the type with integrated throttle, as in Fig. 10 and Fig. Figure 11 shows that the diameter of a section of the first nozzle 22 located near the radial bearing gap 23 is smaller than the diameter of a section of the first nozzle 22 located away from the radial bearing gap 23. Similarly, the diameter of a section of the second nozzle 51 located near the thrust bearing gap 52 is smaller than the diameter of a section of the second nozzle 51 located away from the thrust bearing gap 52.

[0052] The radial bearing 24 and the thrust bearing 53 can each be a hydrostatic bearing of the type with a porous throttle, as in Fig. 12 and Fig. Figure 13 shows that the radial bearing sleeve 21 and the thrust bearing sleeve 50 are made of a porous material. A section of the radial bearing sleeve 21, opposite the first bearing gas supply channel 30, may be provided with a groove 88. The first bearing gas spreads in the groove 88 and is supplied more uniformly to the entire porous material. A section of the thrust bearing sleeve 50, opposite the second bearing gas supply channel 65, may be provided with a groove 89. The second bearing gas spreads in the groove 89 and is supplied more uniformly to the entire porous material.

[0053] The radial bearing 24 and the thrust bearing 53 can each be a hydrostatic bearing of the type with opening throttle, as in Fig. 14 and Fig. Figure 15 shows. In particular, the first nozzle 22 comprises a pocket 90 opposite the radial bearing gap 23 and a throttle bore 91 provided at the bottom of the pocket 90. The diameter of the throttle bore 91 is smaller than the diameter of the pocket 90. The second nozzle 51 comprises a pocket 92 opposite the thrust bearing gap 52 and a throttle bore 93 provided at the bottom of the pocket 92. The diameter of the throttle bore 93 is smaller than the diameter of the pocket 92.

[0054] The radial bearing 24 and the thrust bearing 53 can each be a hydrostatic bearing of the compound throttle type, as in Fig. Figures 16 to 19 show the compound throttle hydrostatic bearing. This type of hydrostatic bearing comprises a combination of a throttle bore and a groove provided to overlap the throttle bore.

[0055] According to Fig. 16. The groove 88 can be configured to overlap the throttle bore 91. For example, the groove 88 in an inner diameter surface of the radial bearing sleeve 21 can be configured to overlap the throttle bore 91. According to Fig. 17 The groove 89 can be designed such that it overlaps the throttle bore 93. For example, the groove 89 in an end face of the thrust bearing sleeve 50 can be designed such that it overlaps the throttle bore 93.

[0056] According to Fig. 18 A first compound throttle can be formed in the first nozzle 22 and in the shaft section 11. For example, a throttle bore 91 and a groove 94 are formed in the first nozzle 22. The groove 94 is formed in the outer circumferential surface of the shaft section 11. The groove 94 serves to distribute the pressure widely. Therefore, the first nozzle 22 and the shaft section 11 form a hydrostatic bearing of the first compound throttle type, which represents a combination of the throttle bore and the groove. According to Fig.19 A second compound throttle can be formed in the second nozzle 51 and the pressure plate 12. For example, a throttle bore 93 and a groove 95 are formed in the second nozzle 51. The groove 95 is formed on the back side of the pressure plate 12. The groove 95 serves to distribute the pressure widely. Therefore, the second nozzle 51 and the pressure plate 12 form a hydrostatic bearing of the second compound throttle type, which represents a combination of the throttle bore and the groove.

[0057] The effects of the hydrostatic spindle 1 according to the present embodiment are described below.

[0058] The hydrostatic spindle 1 according to the present embodiment comprises: the shaft 10; the radial bearing sleeve 21; the thrust bearing sleeve 50; and the magnet 55. The shaft 10 comprises the shaft section 11, which extends in the pressure direction T, the thrust disk 12, which extends from the shaft section 11 in the radial direction R intersecting the pressure direction T, and the turbine blade 15, which is provided on the thrust disk 12. The radial bearing sleeve 21 is arranged so that it faces the shaft section 11 in the radial direction R. The thrust bearing sleeve 50 is arranged so that it faces the thrust disk 12 in the pressure direction T. The magnet 55 attracts the shaft 10 in the pressure direction T. The radial bearing 24, which supports the shaft section 11 in the radial direction R, is formed between the shaft section 11 and the radial bearing sleeve 21.The thrust bearing 53, which supports the shaft 10 in the pressure direction T, is formed between the thrust plate 12 and the thrust bearing sleeve 50. The thrust bearing sleeve 50 and the magnet 55 are arranged opposite the side of the radial bearing sleeve 21 with respect to the thrust plate 12 in the pressure direction T. The distance L in the pressure direction T from the thrust bearing 53 to the center C1 of the radial bearing 24 in the pressure direction T is smaller than the diameter D of the center C2 of the thrust bearing 53 in the radial direction R.

[0059] Since the thrust bearing sleeve 50 and the magnet 55 are arranged opposite to the thrust washer 12 in the pressure direction T on the side of the radial bearing sleeve 21, the area of ​​the radial bearing 24 can be increased. This improves the load-bearing capacity of the hydrostatic spindle 1. Furthermore, since the distance L in the pressure direction T from the thrust bearing 53 to the center C1 of the radial bearing 24 in the pressure direction T is smaller than the diameter D of the center C2 of the thrust bearing 53 in the radial direction R, the radial bearing sleeve 21 and the radial bearing 24 can be extended to a position near the thrust washer 12 of the shaft 10. Therefore, the load-bearing capacity of the hydrostatic spindle 1 is improved.

[0060] In the hydrostatic spindle 1 according to the present embodiment, the shaft section 11 and the thrust plate 12 are provided with a through-bore (first through-bore 16) extending in the pressure direction T. The thrust bearing 53 surrounds the through-bore.

[0061] Therefore, the coating material injection nozzle 78 and the like can be arranged in the through-bore (first through-bore 16). The hydrostatic spindle 1 can be used in an electrostatic coating machine or the like. Furthermore, since the thrust bearing 53 surrounds the through-bore, it prevents the turbine gas from flowing through the thrust bearing gap 52 into the first through-bore 16. When the hydrostatic spindle 1 is used in an electrostatic coating machine, a deterioration of the coating quality can be prevented.

[0062] In the hydrostatic spindle 1 according to the present embodiment, the magnet 55 is arranged in the radial direction R relative to the thrust bearing sleeve 50.

[0063] Therefore, the size of magnet 55 can be reduced. The size and cost of the hydrostatic spindle 1 are reduced.

[0064] In the hydrostatic spindle 1 according to the present embodiment, the magnet 55 is arranged on the outside in the radial direction R relative to the thrust bearing sleeve 50.

[0065] This improves the load resistance properties of the hydrostatic spindle 1.

[0066] In the hydrostatic spindle 1 according to the present embodiment, the magnet 55 has a ring shape.

[0067] Therefore, the coating material injection nozzle 78 and the like can be arranged in the through-bore of the magnet 55. The hydrostatic spindle 1 can be used in an electrostatic coating machine or the like.

[0068] In the hydrostatic spindle 1 according to the present embodiment, the position of the magnet 55 in the pressure direction T is adjustable.

[0069] Therefore, the force with which the magnet 55 attracts the shaft 10 can be adjusted. The size of the thrust bearing gap 52 can be adjusted accordingly. A thrust bearing 53 can be formed that is suitable for the pressure of the second bearing gas supplied to the hydrostatic spindle 1, the uses of the hydrostatic spindle 1, and the like.

[0070] The hydrostatic spindle 1 according to the present embodiment further comprises the housing 57, which accommodates the thrust bearing sleeve 50 and the magnet 55. The thrust bearing sleeve 50 is attached to the housing 57.

[0071] Therefore, the thrust bearing sleeve 50 and the magnet 55 are mechanically protected by the casing 57.

[0072] The hydrostatic spindle 1 according to the present embodiment further comprises the housing 57, which accommodates the thrust bearing sleeve 50 and the magnet 55. The thrust bearing sleeve 50 is elastically supported by the housing 57.

[0073] Therefore, the thrust bearing sleeve 50 and the magnet 55 are mechanically protected by the casing 57. Since the thrust bearing sleeve 50 is elastically supported by the casing 57, it can also more easily follow changes in the position of the shaft 10. Even when the load caused by the gyroscopic moment and vibration of the shaft acts on the shaft 10, the shaft 10 can rotate more stably.

[0074] The hydrostatic spindle 1 according to the present embodiment comprises: the housing 25, which receives the radial bearing sleeve 21; the cover 27, which covers the housing 25; and the plurality of O-rings 41, 42, 43, 44. The plurality of O-rings 41, 42, 43, and 44 are arranged between the housing 25 and the cover 27 and elastically support the housing 25 with respect to the cover 27. In the pressure direction T, at least one O-ring (the O-ring 43) of the plurality of O-rings 41, 42, 43, 44 is arranged between the center C1 of the radial bearing 24 and the center of gravity G1 of the shaft 10.

[0075] Therefore, at least one O-ring (O-ring 43) can be positioned closer to the center of gravity G1 of shaft 10. At least one O-ring can reduce the influence of the gyroscopic moment and vibration of shaft 10 on the radial bearing 24 and the thrust bearing 53. Shaft 10 can then rotate more stably.

[0076] In the hydrostatic spindle 1 according to the present embodiment, the shaft section 11 comprises the first end section 11a, which is provided with the pressure plate 12, and the second end section 11b, which is opposite the first end section 11a. The bell mounting section 18 is formed in the second end section 11b.

[0077] This improves the load resistance properties of the hydrostatic spindle 1. The hydrostatic spindle 1 can be used in an electrostatic coating machine.

[0078] The hydrostatic spindle 1 according to the present embodiment further comprises the bell 19, which is attached to the bell mounting section 18.

[0079] Therefore, the hydrostatic spindle 1 can be used in an electrostatic coating machine.

[0080] The hydrostatic spindle 1 according to the present embodiment comprises: the housing 25, which receives the radial bearing sleeve 21; the cover 27, which covers the housing 25; and the plurality of O-rings 41, 42, 43, 44. The plurality of O-rings 41, 42, 43, and 44 are arranged between the housing 25 and the cover 27 and elastically support the housing 25 with respect to the cover 27. In the pressure direction T, at least one O-ring (the O-ring 43) of the plurality of O-rings 41, 42, 43, 44 is arranged between the center C1 of the radial bearing 24 and the center of gravity G2 of the assembly consisting of shaft 10 and bell 19.

[0081] Therefore, at least one O-ring (O-ring 43) can be positioned closer to the center of gravity G2 of the assembly consisting of shaft 10 and bell 19. When the bell 19 is attached to the shaft 10, at least one O-ring can reduce the influence of the gyroscopic moment and vibration of the shaft 10 on the radial bearing 24 and the thrust bearing 53. The assembly consisting of shaft 10 and bell 19 can then rotate more stably.

[0082] The hydrostatic spindle 1 according to the present embodiment comprises: the housing 25, which receives the radial bearing sleeve 21; the cover 27, which covers the housing 25; and the plurality of O-rings 41, 42, 43, 44. The plurality of O-rings 41, 42, 43, and 44 are arranged between the housing 25 and the cover 27 and elastically support the housing 25 with respect to the cover 27. In the pressure direction T, at least one O-ring (the O-ring 44) of the plurality of O-rings 41, 42, 43, 44 is arranged between the center of gravity G1 of the shaft 10 and the center of gravity G3 of the bell 19.

[0083] Therefore, at least one O-ring (the O-ring 44) can reduce the influence of the load on the radial bearing 24 and the thrust bearing 53 even when the vibration load acts on the side of the bell mounting section 18 (side of the second end section 11b) of the hydrostatic spindle 1. The assembly of shaft 10 and bell 19 can rotate more stably.

[0084] In the hydrostatic spindle 1 according to the present embodiment, the radial bearing 24 and the thrust bearing 53 are each a hydrostatic bearing of the type with integrated throttle, a hydrostatic bearing of the type with porous throttle, a hydrostatic bearing of the type with opening throttle or a hydrostatic bearing of the type with compound throttle.

[0085] This improves the load resistance properties of the hydrostatic spindle 1.

[0086] It is understood that the embodiment and its further developments as disclosed herein are in every respect exemplary and not limiting. The scope of this disclosure is defined by the terms of the claims and not by the foregoing description and is intended to encompass all further developments within the scope and meaning that correspond to the terms of the claims. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] JP 2024-168132

[0001] JP 6935766

[0003] JP 7035594

[0003]

Claims

[1] Hydrostatic spindle (1) comprising: a shaft (10) comprising a shaft section (11) extending in a pressure direction (T), a pressure disk (12) extending from the shaft section (11) in a radial direction (R) intersecting the pressure direction (T), and a turbine blade (15) provided on the pressure disk (12); a radial bearing sleeve (21) arranged such that it is opposite the shaft section (11) in the radial direction (R); a thrust bearing sleeve (50) arranged such that it is opposite the thrust disk (12) in the direction of pressure (T); and a magnet (55) that attracts the shaft (10) in the direction of pressure (T), wherein a radial bearing (24) is formed between the shaft section (11) and the radial bearing sleeve (21), which supports the shaft section (11) in the radial direction (R), a thrust bearing (53) is formed between the pressure plate (12) and the thrust bearing sleeve (50), which supports the shaft (10) in the pressure direction (T), the thrust bearing sleeve (50) and the magnet (55) are arranged opposite to the thrust disk (12) in the direction of pressure (T) on the side of the radial bearing sleeve (21) and a distance (L) in the pressure direction (T) from the thrust bearing (53) to a center (C1) of the radial bearing (24) in the pressure direction (T) is smaller than a diameter (D) of a center (C2) of the thrust bearing (53) in the radial direction (R). [2] Hydrostatic spindle (1) according to claim 1, wherein the shaft section (11) and the pressure plate (12) are provided with a through-bore (16) extending in the pressure direction (T), and the thrust bearing (53) surrounds the through-hole (16). [3] Hydrostatic spindle (1) according to claim 1 or 2, wherein the magnet (55) is arranged inside in the radial direction (R) relative to the thrust bearing sleeve (50). [4] Hydrostatic spindle (1) according to claim 1 or 2, wherein the magnet (55) is arranged externally in the radial direction (R) relative to the thrust bearing sleeve (50). [5] Hydrostatic spindle (1) according to claim 1 or 2, wherein the magnet (55) has a ring shape. [6] Hydrostatic spindle (1) according to claim 1 or 2, wherein a position of the magnet (55) in the pressure direction (T) is adjustable. [7] Hydrostatic spindle (1) according to claim 1 or 2, further comprising a shell (57) which accommodates the thrust bearing sleeve (50) and the magnet (55), wherein the thrust bearing sleeve (50) is attached to the casing (57). [8] Hydrostatic spindle (1) according to claim 1 or 2, further comprising a shell (57) which accommodates the thrust bearing sleeve (50) and the magnet (55), wherein the thrust bearing sleeve (50) is elastically supported by the shell (57). [9] Hydrostatic spindle (1) according to claim 1 or 2, comprising: a housing (25) that accommodates the radial bearing sleeve (21); a cover (27) that covers the housing (25); and a variety of O-rings (41, 42, 43, 44), wherein the multitude of O-rings (41, 42, 43, 44) is arranged between the housing (25) and the cover (27) and elastically supports the housing (25) in relation to the cover (27) and in the pressure direction (T) at least one O-ring (43) of the plurality of O-rings (41, 42, 43, 44) is arranged between the center (C1) of the radial bearing (24) and a center of gravity (G1) of the shaft (10). [10] Hydrostatic spindle (1) according to claim 1 or 2, wherein the shaft section (11) comprises a first end section (11a) which is provided with the pressure disc (12) and a second end section (11b) which is opposite the first end section (11a), and in the second end section (11b) a bell attachment section (18) is formed. [11] Hydrostatic spindle (1) according to claim 10, further comprising a bell (19) which is attached to the bell mounting section (18). [12] Hydrostatic spindle (1) according to claim 11, comprising: a housing (25) that accommodates the radial bearing sleeve (21); a cover (27) that covers the housing (25); and a variety of O-rings (41, 42, 43, 44), wherein the multitude of O-rings (41, 42, 43, 44) is arranged between the housing (25) and the cover (27) and elastically supports the housing (25) in relation to the cover (27) and in the pressure direction (T) at least one O-ring (43) of the plurality of O-rings (41, 42, 43, 44) is arranged between the center (C1) of the radial bearing (24) and a center of gravity (G2) of an assembly consisting of the shaft (10) and the bell (19). [13] Hydrostatic spindle (1) according to claim 11, comprising: a housing (25) that accommodates the radial bearing sleeve (21); a cover (27) that covers the housing (25); and a variety of O-rings (41, 42, 43, 44), wherein the multitude of O-rings (41, 42, 43, 44) is arranged between the housing (25) and the cover (27) and elastically supports the housing (25) in relation to the cover (27) and in the pressure direction (T) at least one O-ring (44) of the plurality of O-rings (41, 42, 43, 44) is arranged between a center of gravity (G1) of the shaft (10) and a center of gravity (G3) of the bell (19). [14] Hydrostatic spindle (1) according to claim 1 or 2, wherein the radial bearing (24) and the thrust bearing (53) are each a hydrostatic bearing of the type with integrated throttle, a hydrostatic bearing of the type with porous throttle, a hydrostatic bearing of the type with opening throttle or a hydrostatic bearing of the type with compound throttle.

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