JP2016223375A - Air turbine drive spindle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air turbine drive spindle in which the lowering of the rotation efficiency of a rotating shaft is suppressed.SOLUTION: An air turbine drive spindle comprises: a rotating shaft 1 which includes a shaft part 1A, and a thrust plate part 1B that is formed so as to extend in a radial direction with respect to the shaft part 1A, and that has a first face, and has a plurality of rotating blades 15 which are formed so as to extend in a thrust direction on the first face; and a box body (a cover 5 and a nozzle plate 6) which rotatably accommodates the rotating shaft 1. The rotating shaft 1 includes a detected part 24 for detecting a rotation number of the rotating shaft 1 on the first face. An opening part 35 which communicates with the outside is formed at a portion opposing the detected part 24 at the box body (the cover 5 and he nozzle plate 6). The air turbine drive spindle further comprises a partitioning part which partitions a space contacting with the detected part 24 and the opening part 35.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an air turbine drive spindle that is rotationally driven by an air turbine.

  A conventional air turbine drive spindle is disclosed in Japanese Patent Application Laid-Open No. 2000-121653.

  Japanese Patent Application Laid-Open No. 2000-121653 discloses a spindle with a rotation sensor provided with a reflective optical rotation sensor for detecting the number of rotations of a main shaft. The rotation sensor is fixed to a housing that houses the rotation shaft. A rotation detector (detected part) is formed on the main shaft, and the rotation detector has a high reflection part that reflects the detection light of the optical rotation sensor.

  There is also known a configuration in which the air turbine drive spindle itself does not include a rotation sensor, and an external device (for example, an electrostatic coating machine) to which the spindle is mounted includes a rotation sensor.

  In any case, in order to guide the rotation sensor to the vicinity of the rotation shaft, an insertion hole for inserting the rotation sensor is provided in the casing that accommodates the rotation shaft in the air turbine drive spindle.

JP 2000-121653 A

  However, in the conventional air turbine drive spindle, the insertion hole for inserting the rotation sensor faces the space where the rotation detector is in contact, and the hole diameter of the insertion hole is equal to or greater than the outer diameter of the rotation sensor. It has been. The space in contact with the rotation detector is provided so that a part of the driving gas supplied to the rotor blades in order to rotate the rotating shaft flows. Therefore, the flow of the driving gas is disturbed by the insertion hole, and there is a problem that the rotation efficiency of the rotating shaft is lowered.

  The present invention has been made to solve the above-described problems. A main object of the present invention is to provide an air turbine drive spindle in which a decrease in rotational efficiency of a rotating shaft is suppressed.

  An air turbine drive spindle according to the present invention includes a shaft portion and a thrust plate portion that is formed to extend in a radial direction with respect to the shaft portion and has a first surface. A rotating shaft having a plurality of rotating blades formed to extend, and a casing that rotatably accommodates the rotating shaft. The rotating shaft includes a detected portion for detecting the number of rotations of the rotating shaft on the first surface. An opening that communicates with the outside is formed in a portion of the housing that faces the detected portion. A partition part is provided for partitioning the space between the detected part and the opening. In this specification, “partition between the space in contact with the detected portion and the opening” means that the space in contact with the detected portion and the opening are not connected via the through-hole, and the driving gas. And a state in which the space in contact with the detected portion and the opening are connected via a through-hole that does not disturb the flow.

  ADVANTAGE OF THE INVENTION According to this invention, the air turbine drive spindle with which the fall of the rotation efficiency of a rotating shaft is suppressed can be provided.

FIG. 3 is a cross-sectional view for explaining an air turbine drive spindle and a spindle holder in the first embodiment. FIG. 3 is a partial cross-sectional view showing an enlarged partition of the air turbine drive spindle in the first embodiment. It is a fragmentary sectional view which shows the modification of the partition part shown in FIG. FIG. 10 is a partial cross-sectional view showing an enlarged partition of an air turbine drive spindle in a second embodiment. FIG. 9 is a partial cross-sectional view showing an enlarged partition portion of an air turbine drive spindle in a third embodiment. It is a fragmentary sectional view which shows the modification of the partition part shown in FIG. It is a fragmentary sectional view which shows the other modification of the partition part shown in FIG. It is a fragmentary sectional view which shows the other modification of the partition part shown in FIG. FIG. 10 is a partial cross-sectional view showing an enlarged partition portion of an air turbine drive spindle in a fourth embodiment. It is a fragmentary sectional view which shows the modification of the partition part shown in FIG. FIG. 10 is a partial cross-sectional view showing an enlarged partition portion of an air turbine drive spindle in a fifth embodiment. It is a fragmentary sectional view which shows the modification of the partition part shown in FIG. It is a fragmentary sectional view which shows the other modification of the partition part shown in FIG. It is a fragmentary sectional view which shows the other modification of the partition part shown in FIG. FIG. 10 is a partial cross-sectional view showing an enlarged partition portion of an air turbine drive spindle in a sixth embodiment. FIG. 6 is a cross-sectional view for explaining through holes formed in a partition portion of an air turbine drive spindle in a fourth embodiment. FIG. 10 is a cross-sectional view for explaining a modified example of a through hole formed in a partition portion of an air turbine drive spindle in a fourth embodiment. FIG. 10 is a cross-sectional view for explaining a through hole formed in a partition portion of an air turbine drive spindle in a sixth embodiment. It is sectional drawing for demonstrating the modification of the fixing method of the partition part in Embodiment 1 and Embodiment 3-5. It is sectional drawing for demonstrating the other modification of the fixing method of the partition part in Embodiment 1 and Embodiment 3-5. It is sectional drawing for demonstrating the other modification of the partition part in Embodiment 4 or Embodiment 5. FIG.

  Embodiments of the present invention will be described below with reference to the drawings. In the following drawings, the same or corresponding parts are denoted by the same reference numerals, and description thereof will not be repeated.

(Embodiment 1)
With reference to FIG. 1 and FIG. 2, the air turbine drive spindle 100 which concerns on Embodiment 1 is demonstrated. FIG. 1A is a cross-sectional view for explaining a spindle holder 40 to which an air turbine drive spindle 100 is attached. FIG. 1B is a cross-sectional view for explaining the air turbine drive spindle 100. FIG. 2 is an enlarged partial sectional view showing the partition portion 33 of the air turbine drive spindle 100. In the following Embodiment 1, the air turbine drive spindle 100 will be described by taking an air turbine drive spindle for an electrostatic coating machine as an example, but the apparatus to which the air turbine drive spindle 100 is applied is not limited to this.

  As shown in FIG. 1B, an air turbine drive spindle 100 includes a rotating shaft 1, a journal bearing 7 that supports the rotating shaft 1 in the radial direction, and a thrust bearing 8 that supports the rotating shaft 1 in the thrust direction. The air supply part (drive air supply path 13 and drive air supply nozzle 14) provided to be capable of jetting gas to the rotary shaft 1 is mainly provided. The journal bearing 7 and the thrust bearing 8 are configured as, for example, static pressure gas bearings.

  The rotating shaft 1 includes a shaft portion 1A having a cylindrical shape, and a thrust plate portion 1B formed so as to extend in the radial direction with respect to the shaft portion 1A. The thrust plate portion 1B is connected to one end portion in the axial direction of the shaft portion 1A. Hereinafter, the other end of the shaft portion 1A located on the rear side of the one end portion of the shaft portion 1A on which the thrust plate portion 1B is provided in the axial direction and on the opposite side of the thrust plate portion 1B in the axial direction of the shaft portion 1A. The end side is called the front side. A first through hole 17 extending in the thrust direction is formed in the shaft portion 1A and the thrust plate portion 1B. When the air turbine drive spindle 100 is configured for an electrostatic coating machine, a conical cup (not shown) is attached to the front end portion of the rotary shaft 1, and the first through hole 17 has an inside. A paint supply pipe is provided for supplying paint to the conical cup. The thrust plate portion 1B is formed with a rotary blade 15, a through hole (through hole portion) 16 (see FIG. 2), and a detected portion 24.

  As shown in FIG. 2, the thrust plate portion 1B has a thin portion 1D whose thickness in the thrust direction is thinner than the region (thick portion 1C) where the region located on the outer peripheral side in the radial direction is located on the center side. ing. The thick part 1C is formed so as to surround the first through hole 17 (see FIG. 1), and the thin part 1D is formed so as to surround the thick part 1C.

  The rotary blade 15 is formed so as to extend in the thrust direction from the surface located on the rear side on the thin portion 1D of the thrust plate portion 1B. The rotary shaft 1 is rotatably provided when the rotary blade 15 receives the gas ejected from the driving air supply nozzle 14 (see FIG. 1). A plurality of rotor blades 15 are formed. The plurality of rotary blades 15 are provided at intervals (gap portions) in the rotation direction of the rotary shaft 1. Preferably, in the plurality of rotor blades 15, adjacent rotor blades 15 are provided at equal intervals. The plurality of rotor blades 15 are arranged along the outer periphery of the thrust plate portion 1B. The cross-sectional shape perpendicular to the thrust direction of the plurality of rotor blades 15 may be any shape. For example, the front curved surface portion that is positioned forward in the rotation direction and is formed in a convex shape in the rotation direction, and the rotation direction And a rear curved surface portion formed in a convex shape in the rotational direction.

  As shown in FIG. 2, a second through hole (through hole portion) 16 extending in the thrust direction is formed on the thin portion 1D of the thrust plate portion 1B. The second through hole 16 extends from the plane located on the front side of the thrust plate portion 1B to the face located on the rear side (the face on which the rotary blades 15 are formed). The second through-hole 16 only needs to have an arbitrary shape when viewed in plan from the thrust direction, and is, for example, a circular shape.

  As shown in FIGS. 1 and 2, the detected portion 24 is formed on the surface located on the rear side in the thick portion 1 </ b> C. The to-be-detected part 24 is surface-treated so that it may become a different reflectance for every some area | region divided | segmented in a rotation direction. For example, in the surface located on the rear side in the thick portion 1C, a half region in the rotation direction is provided so that the intensity of the reflected light is higher when light such as laser light is irradiated than the other half region. It has been.

  A part of the shaft portion 1 </ b> A of the rotating shaft 1 is accommodated in the housing assembly 2. The housing assembly 2 faces each part of the outer peripheral surface of the shaft portion 1A of the rotating shaft 1 and the front plane of the thrust plate portion 1B, and is formed so as to surround a part of the shaft portion 1A. including. Further, the housing assembly 2 includes a housing 3 that is disposed on the outer peripheral side of the bearing sleeve 4 in the radial direction and is fixed to the bearing sleeve 4. The bearing sleeve 4 and the cover 5 are fixed. For example, the housing 3 is connected to the cover 5 via an O-ring.

  The cover 5 is fixed to the nozzle plate 6 in the thrust direction. The nozzle plate 6 is a portion of the rotating shaft 1 that is not accommodated in the housing 3, the bearing sleeve 4 and the cover 5 (the outer peripheral end surface of the thrust plate portion 1B in the radial direction and the surface located on the rear side of the thrust plate portion 1B). It is formed to surround. The cover 5 and the nozzle plate 6 constitute a housing that accommodates the rotating shaft 1.

  The nozzle plate 6 is disposed on the rear side of the rotating shaft 1. Inside the nozzle plate 6, there is formed a flow passage through which the driving gas flows when the driving gas is supplied to and exhausted from the rotary blades 15 formed on the thrust plate portion 1B. The driving gas is, for example, compressed air.

  In the nozzle plate 6, a driving air supply path 13 and a driving air supply nozzle 14 for supplying a driving gas to the rotary blades 15 are formed. One end of the drive air supply path 13 is connected to the drive gas supply port 12 on the outer peripheral surface of the nozzle plate 6, and the other end is connected to the drive air supply nozzle 14. The drive air supply nozzle 14 is provided so as to be able to eject drive gas from the outer side to the inner side of the rotary shaft 1 in the radial direction with respect to the rotary blade 15. A plurality of the drive air supply passages 13 and the drive air supply nozzles 14 may be formed at intervals in the rotational direction. That is, the drive air supply path 13 and the drive air supply nozzle 14 can simultaneously supply the drive gas in the same rotation direction to the rotor blades 15 provided at an arbitrary interval in the rotation direction. It may be provided.

  The nozzle plate 6 is located on the rear side of the thrust plate portion 1B, is opposed to the thrust plate portion 1B in the thrust direction, is located on the rear side of the partition plate 22, and is opposed to the thrust plate portion 1B in the thrust direction. A rear wall portion 28. The partition wall 22 is formed on the nozzle plate 6 on the rear side surface of the thrust plate portion 1 </ b> B at a portion located in the radial direction center side of the driving air supply nozzle 14 and in front of the exhaust hole 11 in the thrust direction. It is provided so as to face each other. If it says from a different viewpoint, the partition 22 is comprised as a connection part connected with the partition member 34 mentioned later in the nozzle plate 6, and has a surface which continues to 33 A of surface parts of the partition part 33. As shown in FIG. The rear wall portion 28 is configured as a connection portion that is connected to a partition member 34 described later in the nozzle plate 6, and has a surface that continues to an end portion 34 </ b> B on the rear side of the partition member 34. The nozzle plate 6 (the partition wall 22 and the rear wall portion 28) is provided with a driving gas supplied to the rotary blade 15 from the driving air supply nozzle 14 so as to be discharged to the outside of the air turbine driving spindle 100. A gas exhaust port 19, a driving gas exhaust space 20, and an exhaust hole 11 are formed.

  The driving gas exhaust port 19 is formed as a third through hole in the partition wall 22, and the driving gas exhaust space 20 is formed between the rear wall portion 28 and the partition wall 22 in the nozzle plate 6.

  The driving gas exhaust port 19 is preferably formed at a position that does not overlap the rotor blade 15 in the thrust direction, and is preferably formed at the center side of the rotor blade 15 in the radial direction. The driving gas exhaust port 19 is preferably formed at a position overlapping the boundary region between the thin portion 1D and the thick portion 1C of the thrust plate portion 1B in the thrust direction. A portion of the partition wall 22 located on the outer peripheral side in the radial direction from the driving gas exhaust port 19 is formed so as to face the rotary blade 15 and the second through hole 16 in the thrust direction. In other words, the space 21 sandwiched between the thrust plate portion 1B (the thin portion 1D thereof) and the partition wall 22 and sandwiched between the adjacent rotary blades 15 includes the driving air supply nozzle 14 and the driving gas exhaust port. 19 are connected to each other. The space 21 is a flow for efficiently applying the gas supplied from the driving air supply nozzle 14 toward the rotary blade 15 to the rotary blade 15 and for efficiently circulating the gas to the drive gas exhaust port 19. A path (driving gas exhaust path) is formed. The space 21 is connected to the bearing gap between the thrust plate portion 1 </ b> B and the bearing sleeve 4 through the through-hole portion 16. The space 21 has a smaller volume than the driving gas exhaust space 20.

  The nozzle plate 6 (the partition wall 22 and the rear wall portion 28) is further formed with two through holes. A fourth through hole 23 is formed in the rear wall portion 28 of the nozzle plate 6 so as to be located at the center side in the radial direction and to be continuous with the first through hole 17 in the thrust direction. A sixth through hole 26 is formed in the partition wall 22 so as to be located on the radial center side and to be continuous with the first through hole 17 and the fourth through hole 23 in the thrust direction. A fifth through hole 25 is formed in the rear wall portion 28 of the nozzle plate 6 on the outer peripheral side in the radial direction with respect to the fourth through hole 23 and on the center side in the radial direction with respect to the driving gas exhaust port 19. . A seventh through hole 27 is formed in the partition wall 22 on the outer peripheral side in the radial direction with respect to the sixth through hole 26 and on the central side in the radial direction with respect to the driving gas exhaust port 19. The fifth through hole 25 and the seventh through hole 27 are formed so as to face the detected portion 24 in the thrust plate portion 1B in the thrust direction. A partition member 34 to be described later is fixed to the fifth through hole 25 and the seventh through hole 27. The fifth through hole 25 has a plurality of portions that are continuous in the thrust direction, and one portion may be provided with a larger diameter than the other portion. In other words, the part facing the fifth through hole 25 in the rear wall portion 28 of the nozzle plate 6 may have a stepped portion.

  The exhaust hole 11 is formed on the rear wall portion 28 of the nozzle plate 6 on the center side in the radial direction with respect to the driving air supply path 13 and the driving air supply nozzle 14. The exhaust hole 11 is formed so as to at least partially overlap the driving gas exhaust port 19 in the thrust direction. An exhaust space 20 is formed between the driving gas exhaust port 19 and the exhaust hole 11 in the rear wall portion 28 of the nozzle plate 6. The exhaust space 20 has a larger volume than the space formed between the thrust plate 1 </ b> B and the partition wall 22.

  As shown in FIG. 2, an opening 35 that communicates with the outside is formed in a portion that faces the detected portion 24 in the casing constituted by the cover 5 and the nozzle plate 6. That is, the opening 35 has an open end on the rear side in the thrust direction. The air turbine drive spindle 100 includes a partition 33 that partitions the space S in contact with the detected portion 24 and the opening 35. Here, the space S in contact with the detected portion 24 refers to a space located between the rotating shaft 1 and the casing, and specifically refers to a space located between the thrust plate portion 1B and the partition wall 22. . The partition portion 33 is configured as an end portion located on the front side in the thrust direction in the partition member 34 provided separately from the partition wall 22. If it says from a different viewpoint, the partition part 33 is a part which opposes the front-end | tip part of a rotation detection apparatus (the optical sensor 46 and the sensor holder 47) in the partition member 34. FIG. The partition portion 33 has a surface portion 33 </ b> A that faces the detected portion 24. The partition member 34 includes a partition portion 33 configured as a closed end portion positioned on the front side in the thrust direction, an end portion 34B positioned on the rear side in the thrust direction and configured as an open end, and the partition portion 33. And a side surface portion 34D extending from the partition portion 33 to the rear end portion 34B.

  The external dimension along the thrust direction of the partition member 34 (the distance between the surface located on the front side of the partition portion 33 and the surface located on the rear side of the rear end portion 34B) is the size of the partition wall 22 of the nozzle plate 6. The distance between the surface located on the front side and the surface located on the rear side of the rear wall portion 28 is set equal to the distance. The external dimension along the radial direction of the partition member 34 is set to be equal to the diameters of the fifth through hole 25 and the seventh through hole 27. The partition member 34 is fitted and fixed in the fifth through hole 25 formed in the rear wall portion 28 and the seventh through hole 27 formed in the partition wall 22. The partition member 34 is only required to be fixed to the casing (the cover 5 and the nozzle plate 6) by an arbitrary method. For example, the partition member 34 is selected from the group consisting of screw fixing, fitting, press-fitting, adhesion, and welding. It is fixed to the housing by at least one fixing method.

  The partition member 34 has a flat end portion located on the front side in the thrust direction. In other words, the surface portion 33A located on the front side in the partition portion 33 is a flat surface. The surface portion 33 </ b> A of the partition portion 33 is provided so as to be on the same plane as the plane located on the front side of the partition wall 22. In the partition member 34, a step 34E is formed at the rear end 34B in the thrust direction so as to be convex in the radial direction with respect to the side 34D. The stepped portion 34E of the partition member 34 and the stepped portion provided in the rear wall portion 28 of the nozzle plate 6 are provided to be able to engage with each other. If the material which comprises the partition part 33 (partition member 34) has translucency (property which transmits substantially the light irradiated from the optical sensor 46 (permeability is 50% or more)). Good. The material which comprises the partition part 33 (partition member 34) is a transparent material or a translucent material, for example. When the material which comprises the partition part 33 (partition member 34) is a transparent material, a high detection sensitivity is realizable about the measurement of the rotation speed of the rotating shaft 1. FIG. Moreover, when the material which comprises the partition part 33 (partition member 34) is a translucent material, it is a case where the space S which contact | connects the to-be-detected part 24 is filled with mist-like gas, or it is not filled. However, the change in the detection sensitivity of the optical sensor 46 accompanying such a change in the environment can be suppressed, and the occurrence of detection failure of the optical sensor 46 can be suppressed.

  The material which comprises the partition part 33 (partition member 34) is at least 1 selected from the group which consists of a polypropylene, a polyacetal, a polycarbonate, polyethylene, an acryl, and glass, for example.

  The opening 35 is configured as a space located on the rear side of the partition 33. Specifically, the opening 35 is configured as a space surrounded by the partition 33, the end located on the rear side of the partition member 34, and the side surface 34D. The opening 35 is provided so that a rotation detecting device (optical sensor 46 and sensor holder 47 in FIG. 2) can be inserted. Although the opening part 35 should just have arbitrary shapes, it has a shape which can be fitted with a polygonal column or a cylinder, for example.

  As shown in FIG. 1B, the optical sensor 46 and the sensor holder 47 are attached to the spindle holder 40. The spindle holder 40 has an accommodating portion 48 provided so as to accommodate at least a portion located on the rear side of the air turbine drive spindle 100. The spindle holder 40 has a bearing gas supply part 41 provided so as to be connectable to the bearing gas supply port 9 of the air turbine drive spindle 100 housed in the housing part 48. The spindle holder 40 has a driving gas supply portion 42 provided so as to be connectable to the driving gas supply port 12 of the air turbine drive spindle 100 housed in the housing portion 48. The spindle holder 40 has an exhaust hole 43 provided so as to be connectable to the exhaust hole 11 of the air turbine drive spindle 100 housed in the housing portion 48. The spindle holder 40 has a paint supply part 44 provided so as to be insertable into the first through hole 17 of the air turbine drive spindle 100 housed in the housing part 48. The spindle holder 40 has an optical sensor 46 and a sensor holder 47 as a rotation detecting device provided so as to be inserted into the partition member 34 of the air turbine drive spindle 100 housed in the housing portion 48. .

  The optical sensor 46 only needs to have an arbitrary configuration capable of detecting the number of rotations of the rotating shaft 1 from the detected portion 24 provided on the rotating shaft 1. For example, the optical sensor 46 irradiates the detected portion 24 with light. And a light receiving unit capable of detecting the reflected light from the detected portion 24. The light emitting unit of the optical sensor 46 only needs to be able to irradiate light having an arbitrary wavelength that can pass through the partition member 34. The light receiving unit of the optical sensor 46 includes a light receiving element such as a photodiode. The sensor holder 47 is for fixing the optical sensor 46 to the spindle holder 40 and the air turbine drive spindle 100. The optical sensor 46 and the sensor holder 47 are provided so as to face at least the partition portion 33 when the air turbine drive spindle 100 is housed in the housing portion 48, for example, close to the partition portion 33. Is provided. The sensor holder 47 may be chamfered at the front end in the thrust direction, for example.

  The housing 3, the bearing sleeve 4, and the cover 5 are provided such that a bearing gap can be formed between the shaft portion 1 </ b> A of the rotary shaft 1 and the bearing sleeve 4 and between the thrust plate portion 1 </ b> B and the bearing sleeve 4. In addition, gas can be supplied to the bearing gap. Specifically, the housing 3, the bearing sleeve 4, and the cover 5 each have a bearing gas supply path 10, and the respective bearing gas supply paths 10 are connected to each other. The bearing gas supply path 10 has one end connected to a bearing gas supply port 9 on the outer peripheral surface of the cover 5 and the other end connected to the bearing gap between the shaft portion 1A and the bearing sleeve 4 and the thrust plate portion 1B and the bearing. It is connected to the bearing gap with the sleeve 4. The hole diameter of the portion connected to the bearing gap in the bearing gas supply passage 10 is smaller than the hole diameter of the bearing gas supply port 9, and a so-called restriction is formed in the portion connected to the bearing gap in the bearing gas supply passage 10. Yes. The journal bearing 7 is configured by supplying the gas supplied from the bearing gas supply port 9 to the bearing gas supply path 10 into the bearing gap between the shaft portion 1 </ b> A and the bearing sleeve 4. The thrust bearing 8 is configured by supplying the gas supplied from the bearing gas supply port 9 to the bearing gas supply path 10 into the bearing gap between the thrust plate portion 1 </ b> B and the bearing sleeve 4.

  In the housing 3, a magnet 30 is disposed in a region facing the thrust plate portion 1B in the thrust direction. The magnet 30 is provided so that a magnetic force can be applied to the thrust plate portion 1B. The magnet 30 is a permanent magnet, for example. The magnet 30 is provided, for example, so as to face the thin portion 1D of the thrust plate portion 1B in which the rotor blade 15 and the second through hole 16 are formed in the thrust direction. The magnet 30 has, for example, an annular shape when viewed from the thrust direction.

  A plurality of second through holes 16 are preferably formed. The plurality of second through holes 16 are respectively formed between adjacent rotary blades 15 in the plurality of rotary blades 15. The plurality of second through holes 16 are formed one by one in all the gaps formed between the adjacent rotor blades 15 in the plurality of rotor blades 15, for example. In other words, two adjacent rotary blades 15 in the plurality of rotary blades 15 are provided so as to sandwich one second through hole 16. At this time, the second through hole 16 may be formed at an arbitrary position in the gap, but is formed at the center of the gap, for example.

  The hole diameter of the second through-hole 16 is the distance between adjacent rotary blades 15 across the second through-hole 16 (for example, the rear curved surface portion of the other rotary blade 15 adjacent to the front curved surface portion of one adjacent rotary blade 15). And the distance). The plurality of second through holes 16 may be formed to have different hole diameters, but are preferably formed to have the same hole diameter. Although the 2nd through-hole 16 can be formed by arbitrary methods, it is formed, for example by drilling the thrust board part 1B with a drill.

  The second through holes 16 adjacent to each other in the plurality of second through holes 16 may be formed at arbitrary intervals, but are preferably provided at equal intervals. The plurality of second through holes 16 are preferably formed so as to be point-symmetric with respect to the rotation center of the rotation shaft 1.

  As shown in FIG. 2, in the thrust plate portion 1B, the boundary region between the thin portion 1D and the thick portion 1C is provided so that the thickness in the thrust direction changes gently. The surface located on the rear side of the thrust plate portion 1B has a curved surface between the thin portion 1D and the thick portion 1C. The portion located on the rear side of the rotary blade 15 and the portion located on the rear side in the thick portion 1C are formed on the same surface extending in the radial direction.

  Next, the operation of the air turbine drive spindle 100 according to the first embodiment will be described.

  A driving gas supplied from a driving gas supply source such as an air compressor (not shown) is supplied from the driving gas supply port 12 to the driving supply nozzle 14 through the driving supply passage 13. The driving gas supplied to the driving air supply nozzle 14 is ejected toward the rotor blade 15 of the thrust plate 1B along a direction substantially parallel to the tangential direction (rotation direction) of the thrust plate 1B. The rotary blade 15 receives the jetted driving gas at the rear curved surface portion. At this time, the driving gas ejected to the rotary blade 15 reaches the outer peripheral side of the rear curved surface portion and is changed in direction by flowing along the rear curved surface portion, and reaches the exhaust space 20 from the driving gas exhaust port 19. Then, the air is exhausted from the exhaust hole 11 to the outside. A reaction force of the force applied to the driving gas acts on the rotary blade 15, and the thrust plate portion 1B is given a rotational torque. Thereby, the rotating shaft 1 rotates along the rotation direction. The rotation speed of the rotating shaft 1 can be set to, for example, tens of thousands rpm or more. That is, the air turbine drive spindle 100 is suitable for a spindle for an electrostatic coating machine, for example.

  Next, functions and effects of the air turbine drive spindle 100 according to Embodiment 1 will be described. The air turbine drive spindle 100 includes a shaft portion 1A and a thrust plate portion 1B having a first surface and extending in the radial direction with respect to the shaft portion 1A, and in the thrust direction on the first surface. A rotating shaft 1 having a plurality of rotating blades 15 formed to extend, and a casing (cover 5 and nozzle plate 6) that rotatably accommodates the rotating shaft 1 are provided. The rotating shaft 1 includes a detected portion 24 for detecting the number of rotations of the rotating shaft 1 on the first surface. An opening 35 that communicates with the outside is formed in a portion of the housing (cover 5 and nozzle plate 6) that faces the detected portion 24. A partition member 34 that partitions the space S in contact with the detected portion 24 and the opening 35 is provided.

  In this way, the rotary shaft 1 is rotationally driven when the rotor 15 receives the driving gas ejected from the driving air supply nozzle 14, and the driving gas flows between the thrust plate portion 1 </ b> B and the partition wall 22. It also circulates in the space S in contact with the detected part 24. Similarly, in a conventional air turbine driven spindle that is rotationally driven, a through hole having a hole diameter equal to or greater than the outer diameter of the rotation detecting device is formed in a region facing the detected portion in the thrust direction. There is a problem in that the flow of the driving gas is disturbed in the space in contact with the detected portion, and the rotation efficiency of the rotating shaft is lowered. Specifically, when there is no partition portion, the through hole (opening portion) into which the optical sensor is inserted has a concave shape when viewed from the rotating shaft side. In addition, the space in contact with the detected portion (the space close to the rotation axis) and the exhaust space are in communication with each other. At this time, when the rotating shaft rotates at high speed, the air in the space close to the rotating shaft is entangled and rotates at high speed. When air rotating at high speed falls into the recess, the airflow is disturbed and rotational resistance is generated. In addition, depending on the pressure distribution, air may flow backward from the exhaust space to a space close to the rotation axis, and in this case as well, the air flow is disturbed and rotational resistance is generated.

  On the other hand, in the air turbine drive spindle 100, the partition 33 partitions the space S in contact with the detected portion 24 and the opening 35, so that the space S in contact with the detected portion 24, that is, the rotation shaft 1. In the space S located between the thrust plate portion 1B and the partition wall 22 of the nozzle plate 6, the turbulence in the flow of the driving gas is suppressed. Therefore, in the air turbine drive spindle 100, a decrease in the rotation efficiency of the rotary shaft 1 is suppressed.

  In the air turbine drive spindle 100, the partition portion 33 includes a flat surface portion 33A facing the detected portion 24, and the housing (the cover 5 and the nozzle plate 6) has a connection portion (partition wall) having a surface continuous to the surface portion 33A. 22) may be included.

  In this way, in the air turbine drive spindle 100, the space S in contact with the detected portion 24 and the opening 35 are partitioned by the partition portion 33, and the space S in contact with the detected portion 24 is Since no recess is formed, the partition 33 is sufficiently suppressed from causing disturbance in the flow of the driving gas in the space S in contact with the detected portion 24. Therefore, in the air turbine drive spindle 100, the reduction in the rotation efficiency of the rotary shaft 1 is sufficiently suppressed.

  In the air turbine drive spindle 100, the material constituting the partition portion 33 is translucent. In this way, by attaching the spindle holder 40 including the optical sensor 46 to the air turbine drive spindle 100, the optical sensor 46 can easily measure the rotational speed of the rotary shaft 1.

  Moreover, it is preferable that the material which comprises the partition part 33 is at least 1 selected from the group which consists of a polypropylene, a polyacetal, a polycarbonate, polyethylene, an acryl, and glass. When the air turbine drive spindle 100 is configured as, for example, a spindle for an electrostatic coating machine and an organic solvent-based paint is used, the partition portion 33 is placed in a solvent atmosphere. In such a case, it is desirable that the constituent material of the partition portion 33 is a material having solvent resistance. Specifically, polypropylene, polyacetal, polycarbonate, and glass are selected. As a result, the life of the air turbine drive spindle 100 can be extended. When solvent resistance is not questioned, polyethylene or acrylic may be used.

  In the air turbine drive spindle 100, the connecting portion of the housing (the cover 5 and the nozzle plate 6) is a partition wall 22 provided so as to face the thrust plate portion 1B in the thrust direction. The partition portion 33 is provided as a separate body from the partition wall 22, and may be fixed to the partition wall 22 or the rear wall portion 28. That is, the partition portion 33 may be provided as a part of the partition member 34 provided separately from the partition wall 22, and the partition member 34 may be fixed to the partition wall 22 or the rear wall portion 28.

  If it does in this way, when it becomes necessary to replace | exchange the partition part 33 (partition member 34), only the partition part 33 (partition member 34) can be replaced | exchanged. Moreover, when it is necessary to replace a member (for example, the nozzle plate 6) that contacts the partition portion 33, the partition portion 33 can be reused as it is. Moreover, since the partition part 33 and the member which touches the partition part 33 can be comprised with a different material, the freedom degree of material selection can be raised.

  The partition member 34 may be fixed to the housing (the cover 5 and the nozzle plate 6) by at least one fixing method selected from the group consisting of screw fixing, fitting, press-fitting, adhesion, and welding.

  In this way, even if the partition member 34 collides with a driving gas such as compressed air at a high speed, positional deviation and detachment with respect to the nozzle plate 6 are suppressed.

  The partition member 34 shown in FIG. 2 is formed so that the side surface portion 34D contacts the partition wall 22 and the rear wall portion 28, but is not limited thereto. In other words, the side surface portion 34 </ b> D of the partition member 34 is formed so as to partition the exhaust space 20 and the opening 35 located behind the partition wall 22 with respect to the space where the detected portion 24 contacts. However, it is not limited to this. Referring to FIG. 3, the partition member 34 is formed such that the side surface portion 34 </ b> D is in contact with the partition wall 22, and the side surface portion 34 </ b> D may not be formed so as to partition the exhaust space 20 and the opening 35. . In this case, the side surface portion 34D is formed only in the seventh through hole 27 of the partition wall 22, and the stepped portion 34E is convex in the radial direction with respect to the side surface portion 34D on the surface located on the rear side of the partition wall 22. It may be formed.

  Even in this case, the space S in contact with the detected portion 24, that is, the space S located between the thrust plate 1 </ b> B of the rotating shaft 1 and the partition wall 22 and the opening 35 are partitioned by the partition portion 33. In the space S, the flow of the driving gas is prevented from being disturbed. Therefore, the air turbine drive spindle shown in FIG. 3 can achieve the same effects as the air turbine drive spindle 100 according to the first embodiment.

(Embodiment 2)
Next, an air turbine drive spindle 110 according to the second embodiment will be described with reference to FIG. The air turbine drive spindle 110 according to the second embodiment basically has the same configuration as the air turbine drive spindle 100 according to the first embodiment, but the partition portion 33 is provided integrally with the partition wall 22. It is different.

  The seventh through hole 27 shown in FIG. 2 is not formed in the partition wall 22, but a recess that is recessed toward the front side is formed. The opening 35 is formed in the recessed portion formed in the partition wall 22, a part of the space 20 located behind the recessed portion, and the fifth through hole 25 formed in the rear wall portion 28 of the nozzle plate 6. Is formed. The partition portion 33 is configured as a recess (a portion where the thickness is reduced) formed in the partition wall 22. If it says from a different viewpoint, the partition part 33 is a part which opposes the front-end | tip part of the rotation detection apparatus (the optical sensor 46 and the sensor holder 47) in the partition 22 in a thrust direction.

  The material constituting the partition wall 22 only needs to have a light-transmitting property (a property of substantially transmitting light irradiated from the optical sensor 46 (transmittance is 50% or more, for example)). The material which comprises the partition part 33 is a transparent material or a translucent material, for example. The material constituting the partition wall 22 is at least one selected from the group consisting of polypropylene, polyacetal, polycarbonate, polyethylene, acrylic, and glass, for example.

  Even in this case, the flow of the driving gas may be disturbed in the space S that is in contact with the detected portion 24 by the partition portion 33, that is, the space S that is located between the thrust plate portion 1 </ b> B of the rotating shaft 1 and the partition wall 22. It is suppressed. Therefore, the air turbine drive spindle 110 according to the second embodiment can achieve the same operational effects as the air turbine drive spindle 100 according to the first embodiment.

(Embodiment 3)
Next, an air turbine drive spindle 120 according to Embodiment 3 will be described with reference to FIG. The air turbine drive spindle 120 according to the third embodiment basically has the same configuration as the air turbine drive spindle 100 according to the first embodiment, but the surface portion 33A where the partition portion 33 faces the detected portion 24. The housing (the cover 5 and the nozzle plate 6) includes a connecting portion (partition 22) that is adjacent to the partition portion 33 in the radial direction and that is farther from the detected portion 24 than the surface portion of the partition portion 33. It is different. In other words, in the air turbine drive spindle 120, at least a part of the surface portion 33 </ b> A of the partition portion 33 is provided with a distance from the detected portion 24 shorter than the partition wall 22 adjacent to the partition portion 33.

  As shown in FIG. 5, when the partition portion 33 is provided separately from the partition wall 22, the partition portion 33 is detected with respect to the partition wall 22 that is a portion adjacent to the partition portion 33 in the radial direction. Protruding toward the portion 24. In the partition portion 33, the entire surface portion 33 </ b> A is configured as a convex portion for the partition wall 22. The partition portion 33 is configured such that a front surface facing the detected portion 24 in the thrust direction (a surface positioned on the front side of the surface portion 33A of the partition portion 33) is parallel to the first surface. .

  Even in this case, the space S in contact with the detected portion 24, that is, the space S located between the thrust plate 1 </ b> B of the rotating shaft 1 and the partition wall 22 and the opening 35 are partitioned by the partition portion 33. In the space S, the flow of the driving gas is prevented from being disturbed. Therefore, the air turbine drive spindle 120 according to the third embodiment can achieve the same operational effects as the air turbine drive spindle 100 according to the first embodiment.

  Further, the interval between the partition portion 33 (the convex portion thereof) and the detected portion 24 is shorter than the interval between the partition wall 22 and the detected portion 24. Therefore, even if the space in contact with the detected part 24 is filled with a mist-like gas, the thickness of the mist-like gas layer is between the partition part 33 (the convex part thereof) and the detected part 24. Since it is thin, the influence (change in detection sensitivity) of the atomized gas on the detection sensitivity of the optical sensor 46 can be reduced. The case where the space in contact with the detected portion 24 is filled with a mist-like gas means that, for example, the driving gas ejected from the driving air supply nozzle 14 to the rotary blade 15 is exhausted from the rotary blade 15 to the space 21. In this case, the water that has dissolved in the gas becomes minute water particles, that is, in the form of a mist.

  Further, at this time, the opening 35 shown in FIG. 5 is closer to the detected part 24 than the opening 35 when the partition 33 as shown in FIG. 2 is provided flat in the thrust direction. It is provided so that it may extend. In this way, the optical sensor 46 can be disposed at a position closer to the detected portion 24. Therefore, the detection sensitivity of the rotational speed of the rotating shaft 1 by the optical sensor 46 can be increased.

  The partition 33 shown in FIG. 5 is configured such that the front surface facing the detected portion 24 in the thrust direction is a flat surface, but is not limited thereto. Referring to FIG. 6, the partition 33 may be configured such that the front surface facing the detected portion 24 in the thrust direction is a curved surface. In this case, the front surface of the partition portion 33 is formed in a spherical shape, for example. At this time, the rear surface of the partition 33 is provided in parallel with, for example, the first surface 1F on which the detected portion 24 is formed. Even in this case, the space in contact with the thrust plate portion 1B of the rotating shaft 1 and the opening 35 are partitioned, and the interval between the partition portion 33 and the detected portion 24 is the partition wall 22 and the detected portion 24. Shorter than the interval. Further, the opening 35 is provided so as to extend to a position closer to the detected part 24 compared to the opening 35 when the partition 33 as shown in FIG. 2 is provided flat in the thrust direction. Yes. Therefore, the air turbine drive spindle including the partition portion 33 shown in FIG. 6 can achieve the same operational effects as the air turbine drive spindle 120 according to the third embodiment shown in FIG.

  Note that the rear surface of the partition 33 may be provided in parallel with the front surface of the partition 33, for example. In other words, the partition part 33 may be provided so that thickness may become fixed. Even in this case, the interval between the partition portion 33 (the convex portion thereof) and the detected portion 24 can be made shorter than the interval between the partition wall 22 and the detected portion 24. Therefore, even if the space in contact with the detected part 24 is filled with a mist-like gas, the thickness of the mist-like gas layer is between the partition part 33 (the convex part thereof) and the detected part 24. Since it is thin, the influence (change in detection sensitivity) of the atomized gas on the detection sensitivity of the optical sensor 46 can be reduced.

  In addition, referring to FIG. 7, part of the partition 33 may be provided in a convex shape toward the detected part 24 rather than the other part. In other words, the partition part 33 may have the convex part 34C. Even in this case, the space in contact with the thrust plate portion 1B of the rotary shaft 1 and the opening 35 are partitioned, and the interval between the convex portion 34C of the partition portion 33 and the detected portion 24 is separated from the partition wall 22. It is shorter than the interval with the detected part 24. Therefore, the air turbine drive spindle including the partition 33 shown in FIG. 7 can achieve the same effect as the air turbine drive spindle 120 shown in FIG.

  The surface located on the front side of the convex portion 34C may be configured as a surface parallel to the first surface on which the detected portion 24 is formed, or may be configured as a curved surface.

  Further, referring to FIG. 8, partition portion 33 is provided integrally with partition wall 22 in the same manner as partition portion 33 in the second embodiment shown in FIG. 4, and is configured as partition portion 33 in partition wall 22. A part of the portion (a portion facing the detected portion 24) may be formed more convexly toward the detected portion 24 than the other portions. In other words, the partition wall 22 may have a convex portion 34 </ b> C in a portion configured as the partition portion 33. Even in this case, the air turbine drive spindle shown in FIG. 8 has the space in contact with the thrust plate portion 1B of the rotating shaft 1 and the opening 35 partitioned, so that the second embodiment shown in FIG. The same effects as the air turbine drive spindle 110 can be obtained. Further, the air turbine drive spindle shown in FIG. 8 is shown in FIG. 5 because the distance between the convex part 34C of the partition part 33 and the detected part 24 is shorter than the distance between the partition wall 22 and the detected part 24. The same effect as the air turbine drive spindle 120 according to the third embodiment can be obtained.

(Embodiment 4)
Next, an air turbine drive spindle 130 according to Embodiment 4 will be described with reference to FIG. The air turbine drive spindle 130 according to the fourth embodiment basically has the same configuration as the air turbine drive spindle 100 according to the first embodiment, except that a through hole 36 is formed in the partition portion 33. Different.

  The through hole 36 is formed in the partition portion 33. The through hole 36 is formed at a position overlapping the optical axis of the light emitted from the optical sensor 46 inserted into the opening 35 in the partition 33, and is formed, for example, one at the center of the partition 33. Yes. The opening 35 is formed in a region located on the rear side of the surface portion of the partition portion 33 (in other words, the through hole 36 from a different point of view).

  The hole diameter Φd of the through hole 36 in the air turbine drive spindle 130 will be described with reference to FIGS. 9 and 16. FIG. 16A is a cross-sectional view for explaining an example of the rotation detection device (optical sensor 46 and sensor holder 47) inserted into the opening 35 of the air turbine drive spindle 130 shown in FIG. FIG. 16B is a cross-sectional view for explaining the hole diameter Φd of the through hole 36 formed in the partition portion 33 of the air turbine drive spindle 130 shown in FIG. 9. As shown in FIG. 9, the hole diameter of the through hole 36 may be a size that does not disturb the flow of the driving gas, and is smaller than the inner diameter dimension of the opening 35 in the radial direction, for example. That is, the hole diameter of the through hole 36 is larger than the hole diameter of the seventh through hole 27 formed to accommodate the partition member 34 in the partition wall 22 (to form the opening 35 into which the optical sensor 46 is inserted). small. In other words, with reference to FIGS. 16A and 16B, the hole diameter Φd of the through hole 36 is smaller than the outermost diameter ΦD1 of the rotation detection device (the optical sensor 46 and the sensor holder 47). Is provided. Referring to FIGS. 16 to 18, the hole diameter Φd of the through hole 36 is preferably not more than the outer diameter φD1 of the sensor holder 47 of the rotation detecting device, and more preferably not more than the outer diameter φD2 of the optical sensor 46. Preferably, it is 50% or less of the maximum value of the inner diameter dimension in the radial direction of the opening 35, more preferably 30% or less, and more preferably 20% or less.

  Even in this way, the space that is in contact with the thrust plate 1 </ b> B of the rotating shaft 1 and the opening 35 are partitioned by the partition 33. For this reason, the air turbine drive spindle 130 according to the fourth embodiment has a space in contact with the thrust plate portion of the rotation shaft and an opening into which the rotation detection device is inserted through a through hole that is equal to or larger than the outer diameter of the rotation detection device. As compared with the conventional air turbine drive spindle connected in this manner, the flow of the drive gas is prevented from being disturbed in the space in contact with the detected portion 24. As a result, in the air turbine drive spindle 130 according to the fourth embodiment, a decrease in the rotation efficiency of the rotary shaft 1 is suppressed.

  Referring to FIG. 22, a plurality of through holes 36 may be formed. In this case, the plurality of through holes 36 may be arranged on the partition portion 33 at a predetermined interval. The plurality of through holes 36 may have the same diameter or may be different from each other. The diameters of the plurality of through holes 36 may be smaller than the width of light emitted from the optical sensor 46. The diameter of the plurality of through holes 36 is preferably less than φD2.

  Referring to FIG. 10, partition portion 33 is provided integrally with partition wall 22 in the same manner as partition portion 33 in the second embodiment shown in FIG. 4, and is configured as partition portion 33 in partition wall 22. The through-hole 36 may be formed in the part which exists. Specifically, even if the portion of the partition wall 22 that is configured as the partition portion 33 has a portion that is thinner than the other portions of the partition wall 22, and the through hole 36 is formed in the thin portion. Good. Even in such a case, the air turbine drive spindle shown in FIG. 10 has the space located between the thrust plate portion 1B of the rotary shaft 1 and the partition wall 22 and the opening 35 partitioned by the partition portion 33 (partition wall 22). Therefore, the same operational effects as the air turbine drive spindle 130 according to the fourth embodiment shown in FIG. 9 can be obtained.

  In addition, although the partition part 33 shown by FIG. 10 is comprised as a recessed part (part where thickness is thin) formed in the partition 22, it is not restricted to this. The partition portion 33 is a portion of the partition wall 22 that faces the tip of the rotation detection device (the optical sensor 46 and the sensor holder 47), and may have a thickness equivalent to that of other portions of the partition wall 22. In this case, a through hole 36 may be formed in a portion of the partition wall 22 that is configured as the partition portion 33. With reference to FIG. 17, the hole diameter Φd of the through hole 36 formed in the partition portion 33 as described above may be formed as follows.

  FIG. 17A illustrates an example of a rotation detection device (an optical sensor 46 and a sensor holder 47) inserted into the opening 35 in the above-described modification of the partition wall 22 (partition portion 33) illustrated in FIG. FIG. FIG. 17B is a cross-sectional view for explaining the hole diameter Φd of the through hole 36 formed in the partition portion 33 of the air turbine drive spindle 130 shown in FIG. Referring to FIGS. 17A and 17B, the hole diameter Φd of the through hole 36 is provided to be smaller than the outer diameter ΦD of the rotation detection device (the optical sensor 46 and the sensor holder 47). Just do it. Even in this case, the partition portion 33 can partition the space in contact with the thrust plate portion of the rotating shaft and the opening 35. Therefore, the air turbine drive spindle provided with the partition portion 33 shown in FIG. 17B has a space in contact with the detected portion, that is, a space in contact with the thrust plate portion of the rotating shaft, as compared with the above-described conventional air turbine drive spindle. In this case, the disturbance of the flow of the driving gas is suppressed.

(Embodiment 5)
Next, an air turbine drive spindle 140 according to Embodiment 5 will be described with reference to FIG. The air turbine drive spindle 140 according to the fifth embodiment basically has the same configuration as the air turbine drive spindle 130 according to the fourth embodiment, but the housing (the cover 5 and the nozzle plate 6) is in the radial direction. It is different in that it includes a connection part (partition 22) that is adjacent to the partition part 33 and is further away from the detected part 24 than the part in which the through hole 36 is formed in the partition part 33. In other words, in the air turbine drive spindle 140, at least a portion of the partition 33 adjacent to the through hole 36 is provided with a shorter distance from the detected portion 24 than the partition 22 adjacent to the partition 33. The hole diameter of the through-hole 36 formed in the partition 33 at this time is the same as that of the through-hole 36 of the partition 33 in the fourth embodiment as shown in FIGS. 16 (A) and 16 (B). What is necessary is just to be provided so that it may become smaller than the outer diameter of a rotation detection apparatus (the optical sensor 46 and the sensor holder 47).

  Even in this case, the space that is in contact with the detected portion 24, that is, the space located between the thrust plate portion 1 </ b> B of the rotating shaft 1 and the partition wall 22 and the opening 35 are partitioned by the partition portion 33, so the thrust Disturbances in the flow of the driving gas in the space in contact with the plate portion 1B are suppressed. Therefore, the air turbine drive spindle 140 according to the fifth embodiment can achieve the same operational effects as the air turbine drive spindle 130 according to the fourth embodiment shown in FIG.

  Further, the interval between the partition portion 33 and the detected portion 24 is shorter than the interval between the partition wall 22 and the detected portion 24. As a result, the air turbine drive spindle 140 according to the fifth embodiment has the partition portion 33 (the convex portion thereof) and the detected portion 24 even when the space in contact with the detected portion 24 is filled with a mist-like gas. The thickness of the atomized gas layer can be reduced between the two. Therefore, according to the air turbine drive spindle 140, the influence (change in detection sensitivity) of the mist gas on the detection sensitivity of the optical sensor 46 can be reduced.

  Referring to FIG. 12, the partition 33 may be configured such that the front surface facing the detected portion 24 in the thrust direction is a curved surface. The partition 33 shown in FIG. 12 has a configuration in which a through hole 36 is formed in the partition 33 shown in FIG. In this case, the front surface of the partition 33 is formed in, for example, a spherical shape, and the through hole 36 is formed at the top of the front surface. Even in this case, the space in contact with the thrust plate portion 1B of the rotating shaft 1 and the opening 35 are partitioned, and the interval between the partition portion 33 (the convex portion thereof) and the detected portion 24 is the partition wall 22. And the interval between the detected portion 24 and the detected portion 24 is shorter. Therefore, the air turbine drive spindle provided with the partition portion 33 shown in FIG. 12 can achieve the same effect as the air turbine drive spindle 140 according to the fifth embodiment shown in FIG.

  Referring to FIG. 13, part of the partition 33 may be provided in a convex shape toward the detected part 24 rather than the other part. In other words, the partition part 33 may have the convex part 34C. At this time, a through hole 36 may be formed on the convex portion 34C. The partition 33 shown in FIG. 13 has a configuration in which a through-hole 36 is formed in the convex portion 34C of the partition 33 shown in FIG. The through hole 36 is formed, for example, at the center of the convex portion 34C. Even in this case, the space in contact with the thrust plate portion 1B of the rotary shaft 1 and the opening 35 are partitioned, and the interval between the convex portion 34C of the partition portion 33 and the detected portion 24 is separated from the partition wall 22. It is shorter than the interval with the detected part 24. Therefore, the air turbine drive spindle provided with the partition portion 33 shown in FIG. 12 can achieve the same effect as the air turbine drive spindle 140 according to the fifth embodiment shown in FIG.

  Referring to FIG. 14, the partition 33 is provided integrally with the partition wall 22, and a part of the part configured as the partition part 33 in the partition wall 22 is more at the detected part 24 than the other part. It may be formed in a convex shape, and a through hole 36 may be formed in a part thereof. As for the partition part 33 shown by FIG. 14, the through-hole 36 may be formed in the convex part 34C of the partition part 33 shown by FIG. Even in this case, the space in contact with the thrust plate portion 1B of the rotating shaft 1 and the opening 35 are partitioned, and the interval between the partition portion 33 (the convex portion thereof) and the detected portion 24 is the partition wall 22. And the interval between the detected portion 24 and the detected portion 24 is shorter. Therefore, the air turbine drive spindle including the partition 33 shown in FIG. 14 can achieve the same effects as the air turbine drive spindle 140 according to the fifth embodiment shown in FIG.

  In addition, with reference to FIG. 22, in the partition part 33 shown by FIGS. 9-14, the through-hole 36 may be formed with two or more. In this case, the plurality of through holes 36 may be arranged on the partition portion 33 at a predetermined interval. The plurality of through holes 36 may have the same diameter or may be different from each other. The hole diameters of the plurality of through holes 36 may be smaller than the width of the light emitted from the optical sensor 46 or may be less than the outer diameter φD2 of the optical sensor 46. Moreover, the partition part 33 shown by FIGS. 9-14 may not be the material which permeate | transmits light.

(Embodiment 6)
Next, an air turbine drive spindle 150 according to Embodiment 6 will be described with reference to FIG. The air turbine drive spindle 150 according to the sixth embodiment basically has the same configuration as that of the air turbine drive spindle shown in FIG. 10, but is attached to the spindle holder 40 shown in FIG. 1 (B). The optical sensor 46 is different in that the front end portion of the optical sensor 46 is provided on the same plane as the surface 22a located on the front side of the partition wall 22 configured as the partition portion 33.

  The tip of the rotation detection device has a tapered shape. For example, the optical sensor 46 is configured as a columnar body, and the tip of a sensor holder 47 provided so as to surround the optical sensor 46 has a chamfered shape. The sensor holder 47 has an outer peripheral surface 47a that extends in a direction intersecting the thrust direction at the tip portion. An inner peripheral surface 36a of the through hole 36 formed in a portion of the partition wall 22 that is configured as the partition portion 33 is provided so as to be in contact with (for example, surface contact) or close to the outer peripheral surface 47a of the sensor holder 47. .

  The hole diameter Φd of the through hole 36 in the air turbine drive spindle 150 will be described with reference to FIGS. 15 and 18. FIG. 18A is a cross-sectional view for explaining an example of a rotation detection device (optical sensor 46 and sensor holder 47) inserted into opening 35 of air turbine drive spindle 150 shown in FIG. FIG. 18B is a cross-sectional view for explaining the hole diameter Φd of the through hole 36 formed in the partition portion 33 of the air turbine drive spindle 150 shown in FIG. As shown in FIG. 15, FIG. 18 (A) and FIG. 18 (B), the hole diameter Φd of the through hole 36 on the front surface 22a of the partition wall 22 is determined by the rotation detection device (optical sensor 46 and sensor holder). 47) so as to be smaller than the outermost diameter ΦD1. On the other hand, the hole diameter Φd of the through hole 36 on the rear surface 22b in the partition wall 22 is provided to be larger than the outer diameter ΦD1 of the rotation detection device (optical sensor 46 and sensor holder 47). Also good. In other words, the through-hole 36 has only to be provided so that the hole diameter on at least the front surface 22a of the partition wall 22 is smaller than the inner diameter dimension (maximum width) of the opening 35 in the radial direction. In other words, the inner peripheral surface 36a of the through hole 36 may be inclined with respect to the thrust direction.

  Even in this case, the air turbine drive spindle 140 according to the sixth embodiment is configured such that the space in contact with the thrust plate portion 1B of the rotating shaft 1 and the opening 35 are partitioned by the portion configured as the partition portion 33 in the partition wall 22. Therefore, the same operational effects as those of the air turbine drive spindle 100 including the partition 33 shown in FIG. 10 can be obtained. Furthermore, in the air turbine drive spindle 140 according to the sixth embodiment, the optical sensor 46 is disposed closer to the detected portion 24 than the air turbine drive spindle including the partition 33 shown in FIG. Can do. Therefore, according to the air turbine drive spindle 140 according to the sixth embodiment, the detection sensitivity of the rotational speed of the rotary shaft 1 by the optical sensor 46 can be increased.

  Further, in the air turbine drive spindle according to the first embodiment and the third to fifth embodiments, the partition portion 33 can be configured as a separate body from the partition wall 22, but at this time, the partition portion 33 is separated from the partition member 34 as described above. The partition member 34 is fixed to the partition wall 22 by being fixed to the partition wall 22 by at least one fixing method selected from the group consisting of screw fixing, fitting, press-fitting, adhesion, and welding. It only has to be fixed. Referring to FIG. 19, the partition member 34 (partition portion 33) may be fixed to the partition wall 22 by screw fixing. In this case, for example, portions of the seventh through hole 27 of the partition wall 22 and the side surface portion 34D of the partition member 34 that are in contact with the seventh through hole 27 of the partition wall 22 are threaded together. Even in this case, it is possible to suppress separation of the partition portion 33 and the partition wall 22 in a state where the air turbine drive spindle 100 is rotationally driven. Referring to FIG. 20, the partition member 34 (partition portion 33) may be fixed to the partition wall 22 by being fitted into the partition wall 22. In this case, in the partition member 34, the side surface portion 34D in the thrust direction is formed with a protruding portion 39 that is formed in a convex shape in the radial direction with respect to the side surface portion 34D. The protruding portion 39 and the stepped portion 34E are provided so as to sandwich the rear wall portion 28 of the nozzle plate 6 in the thrust direction. Even in this case, it is possible to suppress separation of the partition portion 33 and the partition wall 22 in a state where the air turbine drive spindle 100 is rotationally driven.

  In the present embodiment, both the journal bearing 7 and the thrust bearing 8 may be configured as static pressure gas bearings. In such an air turbine drive spindle 100, since the rotary shaft 1 is supported in a non-contact manner on the housing assembly 2, the progress of wear is suppressed under normal use conditions. As a result, the air turbine drive spindle 100 has a long life. Further, since the lubricant is unnecessary, the inside of the air turbine drive spindle 100 (for example, the first through hole 17) is not contaminated by the lubricant. Therefore, the air turbine drive spindle 100 provided with a static pressure gas bearing is suitable for an electrostatic coating machine, for example.

  In the present embodiment, the journal bearing 7 and the thrust bearing 8 are both configured as static pressure gas bearings, but are not limited thereto. The journal bearing 7 and the thrust bearing 8 may be rolling bearings such as a thrust roller bearing. Even in this case, the thrust plate portion 1B is formed with a plurality of through-hole portions 16 extending in the thrust direction, so that the thrust plate portion, the space in contact with the front surface of the thrust plate portion 1B at the time of rotational driving, and the rear side The pressure difference with the space in contact with the surface can be reduced.

  Each embodiment disclosed this time must be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  The present invention is applied to an air turbine drive spindle that is rotationally driven by an air turbine, and is particularly advantageously applied to an air turbine drive spindle that is rotated at a high speed.

  1 rotating shaft, 1A shaft portion, 1B thrust plate portion, 1E outer peripheral end surface, 2 housing assembly, 3 housing, 4 bearing sleeve, 5 cover, 6 nozzle plate, 7 journal bearing, 8 thrust bearing, 9 bearing gas supply port, 10 Bearing gas supply path, 11 exhaust hole, 12 driving gas supply port, 13 driving air supply path, 14 driving air supply nozzle, 15 rotor blade, 16 through hole (second through hole), 16A opening, 17 1st through-hole, 18 clearance part, 19 drive gas exhaust port, 20 exhaust space, 21 space, 22 partition, 23 4th through-hole, 24 detected part, 25 5th through-hole, 26 6th through-hole, 27 7th through hole, 30 magnet, 33 partition, 33C convex, 34 partition member, 34D side, 34E step, 35 opening, 36 through hole, 39 protrusion, 40 spin Dollar holder, 41 Bearing gas supply unit, 42 Drive gas supply unit, 44 Paint supply unit, 46 Optical sensor, 47 Sensor holder, 48 Storage unit, 100, 110, 120, 130, 140, 150 Air turbine drive spindle.

Claims (11)

A plurality of shaft portions and a thrust plate portion having a first surface and extending in the radial direction with respect to the shaft portions, and a plurality of portions formed on the first surface so as to extend in the thrust direction. A rotating shaft having a rotating blade of
A housing that rotatably accommodates the rotating shaft,
The rotating shaft includes a detected portion for detecting the number of rotations of the rotating shaft on the first surface,
An opening that communicates with the outside is formed in a portion of the housing that faces the detected portion.
An air turbine drive spindle, comprising: a partition that partitions a space in contact with the detected portion and the opening. The partition includes a flat surface portion facing the detected portion,
The air turbine drive spindle according to claim 1, wherein the housing includes a connection portion having a surface continuous with the surface portion. The partition portion includes a surface portion facing the detected portion,
2. The air turbine drive spindle according to claim 1, wherein the casing includes a connection portion that is adjacent to the partition portion in the radial direction and is farther from the detected portion than the surface portion of the partition portion. The connection portion of the housing is a partition wall provided to face the thrust plate portion in the thrust direction,
4. The air turbine drive spindle according to claim 2, wherein the partition portion is provided separately from the partition wall, and is fixed to the partition wall or the rear wall portion.   The air turbine drive spindle according to claim 4, wherein a material constituting the partition portion is translucent.   The air turbine drive spindle according to claim 5, wherein the material constituting the partition is at least one selected from the group consisting of polypropylene, polyacetal, polycarbonate, polyethylene, acrylic, and glass.   The said partition part is fixed to the said housing | casing by the at least 1 fixing method selected from the group which consists of screw fixation, fitting, press fit, adhesion | attachment, and welding. The air turbine drive spindle as described in. The connection portion of the housing is a partition wall provided to face the thrust plate portion in the thrust direction,
The air turbine drive spindle according to claim 2 or 3, wherein the partition portion is provided integrally with the partition wall.   The air turbine drive spindle according to claim 8, wherein the material constituting the partition wall has translucency.   10. The air turbine drive spindle according to claim 9, wherein the material constituting the partition wall is at least one selected from the group consisting of polypropylene, polyacetal, polycarbonate, polyethylene, acrylic, and glass. A through hole is formed in the partition part,
The air turbine drive spindle according to any one of claims 1 to 10, wherein a diameter of the through hole is smaller than an inner diameter of the opening in the radial direction.

Images