JP2008025604A - Driving device for air spindle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a driving device for an air spindle which can prevent the generation of vibrations, noises, etc. and can keep a high speed and highly accurate rotation. <P>SOLUTION: The driving device 1 for the air spindle comprises a rotary spindle 3, a first plate member 4, and a second plate member 5, which are supported by air bearings 6A to 6C in a floating state from a body 2, a first air supply passage 2g penetrating from the outer surface of the body to a hollow portion, second air supply passages 2a to 2c penetrating from the outer surface of the body to each of the respective air bearings 6, first air discharge passages 2d to 2f penetrating from the respective air bearings 6A to 6C to the outer surface of the body, groove portions 3a provided on the outer surface of the body, third air supply passages 3b, 3c penetrating from the bottom portions of the groove portions to one end of the rotary spindle, and second air discharge passages 4a, 4b provided on the first plate member so as to communicate with the third air supply passages. Air penetrates the first air supply passage, the groove portions, the third air supply passages, and the second air discharge passages in this order, and then gushes outward. As a result, the first plate member, etc. rotate. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a drive device for an air spindle, and more particularly, to a drive device for an air spindle that can obtain submicron-class high rotational accuracy and is used in ultraprecision machining, ultraprecision measuring instruments, and the like.

  Conventionally, an air spindle that is inserted into a hollow portion of a housing and supported in a floating state by an air bearing in ultra-precision machining or an ultra-precision measuring instrument such as a cutting machine equipped with a rotating grindstone, a magnetic head, or a rotational viscometer. (Air shaft) is used, and a driving device such as a motor having a rotor built in the rotating shaft directly or a belt via a coupling is used as a rotation driving means of the air spindle.

  However, the drive means that directly builds in the rotor of the motor on the rotating shaft has less vibration compared to the other, high speed and high output, but the motor space is not required and compact, the motor generates heat, There are problems such as high costs. In addition, the belt drive via the coupling has the problem of low frequency vibration due to slipping and torque slip, and the noise during machining is high, so the vibration is small and the noise can be reduced. Was demanded.

  Therefore, in order to solve the above problem, Patent Document 1 discloses that a disc-shaped injection plate is inserted into the top of a hollow rotary shaft that is inserted into a hollow portion of a housing and supported in a floating state by an air bearing. A gas passage that passes through the axis of the hollow rotary shaft, and is perpendicular to the gas passage at both ends of the gas passage, and , A branch path is provided point-symmetrically with respect to the axis of the hollow rotary shaft, a gas discharge path whose tip penetrates the side wall of the disk-shaped injection plate is provided in this branch path, and compressed gas is supplied to the hollow rotary shaft, There has been proposed an air spindle that rotates a disk-shaped injection plate by discharging compressed gas out of the disk-shaped injection plate via a passage, a branch path, and a gas discharge path, and rotates around a hollow rotating shaft. .

JP 2005-147379 A

  However, in the air spindle described in Patent Document 1, since the compressed gas is introduced into the hollow rotating shaft when the compressed gas is supplied to the disc-shaped injection plate, the joint portion is used. Vibration, noise, heat generation, friction loss, etc. occur, and there is a problem that high-speed and high-precision rotation cannot be obtained.

  Therefore, the present invention has been made in view of the problems in the conventional air spindle described above, and can solve various problems that have occurred in the conventional joint portion and maintain high-speed and high-precision rotation. An object is to provide a drive device for an air spindle.

  In order to achieve the above object, the present invention is an air spindle driving device, which is inserted into a hollow portion of a main body and supported in a floating state by a first air bearing, and one end of the rotating shaft. The first plate-like member supported by the second air bearing and fixed to the other end of the rotary shaft so as to be in a floating state with respect to the main body, and in a floating state with respect to the main body The second plate-like member supported by the third air bearing, the first air supply passage penetrating from the outer surface of the main body to the hollow portion, and the first air supply path from the outer surface of the main body. The first air bearing, the second air bearing, and the third air bearing, the second air supply passage penetrating to each of the first air bearing, the second air bearing, and the third air bearing, the first air bearing, the second air bearing, and the third air. A first air exhaust passage extending from each of the bearings to the outer surface of the body; A groove portion provided on the outer peripheral surface of the rotary shaft so as to communicate with the first air supply passage; a third air supply passage penetrating from the bottom of the groove portion to the one end of the rotary shaft; A plate-like member having a second air discharge path provided so as to communicate with the third air supply path, and the air supplied through the first air supply path is the groove section, After passing through the third air supply path and the second air discharge path in this order, the first plate member, the rotation shaft, and the second plate member rotate by being ejected to the outside. It is characterized by.

  And according to this invention, the air supplied via the 1st air supply path is the groove part on the outer peripheral surface of a rotating shaft, a 3rd air supply path, and the air discharge path of a 1st plate-shaped member. After sequentially passing, the first plate member, the rotation shaft, and the second plate member rotate by ejecting to the outside. At this time, the rotation shaft is a member other than the first and second plate members. Since it is in a completely non-contact state with the member, vibrations, noises, and the like as in the case of using a conventional rotary joint do not occur, and high-speed and high-precision rotation can be maintained. In addition, by eliminating the need for a rotary joint, maintenance work around the rotary joint, which was necessary in the past, is no longer necessary, friction powder is not generated, and contamination problems due to grease, etc. are eliminated. The number of parts can be reduced.

  In the air spindle drive device, the first to third air bearings may be bearings having a porous sintered layer.

  In the air spindle driving device, the rotation shaft and the first plate member may be integrally formed, and the rotation shaft and the second plate member are formed integrally. It can also be configured as follows.

  Furthermore, in the air spindle driving device, a part of the second air supply path is formed in a T shape so as to penetrate from the outer surface of the main body to the second air bearing and the third air bearing. Can be provided. Thereby, while being able to supply air to a 2nd air bearing and a 3rd air bearing simultaneously, the process of a rotating shaft becomes easy.

  Further, in the air spindle driving device, the first air discharge path is formed at a boundary portion between the first air bearing and the second air bearing, and the first air bearing and the third air. It can provide in a V shape so that it may penetrate from the boundary part with a bearing to the outer surface of the said main body. Thereby, the air can be efficiently discharged from both the boundary portions where the air tends to stay, and can be simultaneously discharged from the first to third air bearings to the outside of the main body.

  In the air spindle drive device, the third air supply path may be configured to extend in the axial direction of the rotating shaft. Thereby, while being able to make the 3rd air supply path shortest, the process of a rotating shaft also becomes easy.

  In the air spindle driving device, the second air discharge path can be extended perpendicularly to the axial direction of the rotary shaft. Accordingly, the second air discharge path can be shortened, the first plate member can be efficiently rotated, and the processing of the first plate member is facilitated.

  As described above, according to the present invention, it is possible to provide an air spindle drive device that can prevent generation of vibration, noise, and the like, and that can maintain high-speed and high-precision rotation.

  Next, embodiments of the present invention will be described with reference to the drawings.

  1 to 3 show an embodiment of an air spindle driving device according to the present invention. This device 1 is roughly divided into a main body 2, a rotating shaft 3, a disc member (first plate-like shape). Member) 4, a thrust plate (second plate-like member) 5, an air bearing 6 (6 </ b> A to 6 </ b> C) that supports the rotating shaft 3, the disk member 4, and the thrust plate 5 in a floating state with respect to the main body 2. The air supply port 8 (6A to 6C) for supplying air to the air bearing 6 and the air supply port 10 for supplying air for rotating the disk member 4 are configured.

  As shown in FIG. 1 and FIG. 2 (c), the main body 2 is formed in a hollow cylindrical shape and includes an air supply port 8 on the outer peripheral surface. The air supply port 8 is provided to supply air to the air bearings 6B and 6C, and air is supplied to the air bearings 6B and 6C through the air supply paths 2a to 2c. Although not shown, the outer peripheral surface of the main body 2 is provided with another air supply port for supplying air to the air bearing 6A, and an air supply path that connects the air supply port and the air bearing 6A is formed. Is done. Further, the main body 2 is provided with air discharge paths 2d to 2f for discharging the air supplied to the air bearings 6A to 6C, and an exhaust port 9.

  As shown in FIG. 3B, the main body 2 includes another air supply port 10, and this air supply port 10 communicates with the groove portion 3 a of the rotating shaft 3 through the air supply path 2 g. Air is supplied to the air supply port 10 and the air supply port 8 shown in FIG. 2C via an air pump and a tube (not shown).

  As shown in FIGS. 2 and 3, the rotary shaft 3 is formed in a hollow cylindrical shape, is fitted into the hollow portion of the main body 2, and is supported in a floating state by the air bearing 6A. Further, a groove portion 3 a communicating with the air supply path 2 g of the main body 2 is formed on the outer peripheral surface of the rotating shaft 3 over the entire circumference. An air supply path 3b is formed in the bottom of the groove 3a, and an air supply path 3c extends from the air supply path 3b in parallel to the axial direction of the rotary shaft 3.

  The disc member 4 is formed in a disc shape having a hollow portion at the center, and is supported in a floating state with respect to the main body 2 by the air bearing 6B. The disc member 4 is fixed to the left end portion of the rotating shaft 3 via a bolt 11 shown in FIG. 3A, and communicates with the air supply path 3c of the rotating shaft 3 to discharge air to the outside. Air discharge passages 4a and 4b. These air discharge paths 4 a and 4 b are formed point-symmetrically with respect to the center of the disk member 4.

  The thrust plate 5 is formed in a disk shape having a hollow portion at the center, and is supported in a floating state with respect to the main body 2 by the air bearing 6C. The thrust plate 5 is fixed to the right end portion of the rotary shaft 3 via a bolt (not shown).

  The air bearings 6A to 6C have a porous sintered layer, and air is always supplied to the air bearings 6B and 6C from the air supply port 8 through the air supply paths 2a to 2c. A constant pressure of air is interposed between the member 4 and the thrust plate 5, and the disc member 4 and the thrust plate 5 are supported in a floating state with respect to the main body 2. Air is always supplied to the air bearing 6A from an air supply port (not shown) through an air supply path (not shown) in the main body 2 so that air with a constant pressure is supplied between the main body 2 and the rotary shaft 3. The rotary shaft 3 is supported in a floating state with respect to the main body 2.

  Next, the operation of the air spindle drive device 1 having the above-described configuration will be described with reference to the drawings. In the following description, the case where the air spindle driving device 1 is used for polishing will be described as an example.

  In FIG. 2C, a workpiece (not shown) to be polished is fixed to the right surface of the thrust plate 5 via bolts, jigs and the like.

  An air pump (not shown) is driven to supply air from the air supply port 8 to the air bearings 6B and 6C through the air supply passages 2a to 2c via a tube or the like. Similarly, air is supplied to the air bearing 6A from another intake port (not shown). Thereby, an air layer of 3 to 20 μm is formed between the main body 2 and each of the rotating shaft 3, the disk member 4 and the thrust plate 5, and each of the rotating shaft 3, the disk member 4 and the thrust plate 5 is The main body 2 is supported in a floating state. Air from the air bearings 6A to 6C is discharged from the exhaust port 9 to the outside of the main body 2 through the air discharge paths 2d to 2f.

  Next, the disk member 4 is rotated for polishing. In FIG. 3B, when an air pump (not shown) is driven and air is introduced from the air supply port 10 via a tube or the like, the introduced air is supplied to the air supply path 2g, the groove 3a, the air supply paths 3b, 3c. After passing through, it passes through two pairs of air discharge passages 4a and 4b of the disk member 4, and as shown in FIG. The disk member 4 rotates in the arrow Y direction by the reaction force of the blown air. At the same time, the rotating shaft 3 and the thrust plate 5 also rotate in the same direction.

  The work mounted on the disk member 4 is also rotated by the rotation of the disk member 4, and the surface of the work is polished by bringing a polishing pad into contact with the work.

  When the polishing of the workpiece is completed, the air pump is stopped, the introduction of air into the air supply port 10 is stopped, the rotation of the disk member 4 and the like is stopped, and then the air is supplied to the air bearings 6A to 6C Also stop.

  In the embodiment described above, the air bearings 6A to 6C have the porous sintered layer. However, the present invention is not necessarily limited to the one having the porous sintered layer. An air bearing that can support the rotating shaft 3, the disk member 4, and the thrust plate 5 with an air layer of about 3 to 20 μm interposed therebetween can be used.

  Further, the rotating shaft 3, the disk member 4 and the thrust plate 5 are not integrally structured with bolts or the like, but the rotating shaft 3 and either the disk member 4 or the thrust plate 5 are integrally structured. It can also be.

  Further, the air supply paths 2a to 2c to the air bearings 6A to 6C are not T-shaped but can take various paths, and an air supply path is provided for each of the air bearings 6A to 6C. May be. Similarly, the air discharge paths 2d to 2f may be provided individually for the air bearings 6A to 6C.

  Further, the air supply path 3c is not necessarily limited to the configuration extending in the axial direction of the rotating shaft 3, and the air discharge paths 4a and 4b can be maintained as long as the disk member 4 can be smoothly rotated. It is not limited to the extending direction of illustration.

1 is an external perspective view showing an embodiment of an air spindle driving device according to the present invention. It is a figure which shows one Embodiment of the drive device for air spindles concerning this invention, Comprising: (a) is a front view, (b) is the sectional view on the AA line of (a), (c) is (a). It is a BB sectional view taken on the line. It is a figure which shows one Embodiment of the drive device for air spindles concerning this invention, Comprising: (a) is a side view of Fig.3 (a), (b) is CC sectional view taken on the line of (a). .

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Air spindle drive 2 Main body 2a-2c Air supply path 2d-2f Air discharge path 2g Air supply path 3 Rotating shaft 3a Groove part 3b Air supply path 3c Air supply path 4 Disc member 4a Air discharge path 4b Air discharge path 5 Thrust plate 6 (6A to 6C) Air bearing 8 Air supply port 9 Air exhaust port 10 Air supply port 11 Bolt

Claims (7)

A rotating shaft that is inserted into the hollow portion of the main body and is supported in a floating state by the first air bearing;
A first plate member fixed to one end of the rotating shaft and supported by a second air bearing so as to float with respect to the main body;
A second plate-like member fixed to the other end of the rotating shaft and supported by a third air bearing so as to float with respect to the main body;
A first air supply path penetrating from the outer surface of the main body to the hollow portion;
A second air supply path that penetrates from the outer surface of the main body to each of the first air bearing, the second air bearing, and the third air bearing;
A first air exhaust passage penetrating from each of the first air bearing, the second air bearing and the third air bearing to an outer surface of the main body;
A groove provided on the outer peripheral surface of the rotating shaft so as to communicate with the first air supply path;
A third air supply path that penetrates from the bottom of the groove to the one end of the rotating shaft;
A second air discharge path provided in the first plate-like member so as to communicate with the third air supply path;
The air supplied through the first air supply path passes through the groove, the third air supply path, and the second air discharge path in this order, and then is ejected to the outside. An air spindle driving device, wherein the plate member, the rotating shaft, and the second plate member rotate.   The air spindle driving device according to claim 1, wherein the first to third air bearings have a porous sintered layer.   The air spindle according to claim 1 or 2, wherein the rotary shaft and the first plate-like member, or the rotary shaft and the second plate-like member are integrally formed. Drive device.   The part of the second air supply path is provided in a T shape so as to penetrate from the outer surface of the main body to the second air bearing and the third air bearing, respectively. The drive device for an air spindle according to 2 or 3.   The first air discharge path extends from the boundary portion between the first air bearing and the second air bearing, and from the boundary portion between the first air bearing and the third air bearing. 5. The air spindle driving device according to claim 1, wherein the air spindle driving device is provided in a V shape so as to penetrate the outer surface of the air spindle.   6. The air spindle driving device according to claim 1, wherein the third air supply path extends in an axial direction of the rotating shaft. 7.   The air spindle driving device according to any one of claims 1 to 6, wherein the second air discharge path extends perpendicularly to an axial direction of the rotating shaft.

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