JP2013113344A - Static pressure gas bearing structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provided a static pressure gas bearing structure that is robust against load variations and enables reduction in size and weight of a mounted device.SOLUTION: An air bearing 1 comprises: a magnetic-force generating part 11 that generates a magnetic force which attracts a mating member; a compressed-air supply part 12 that is arranged around the magnetic-force generating part 11 and discharges compressed air toward the mating member; a base plate 13 to which the magnetic-force generating part 11 and the compressed-air supply part 12 are attached; and a ball joint 14 that allows the inclination of the air bearing 1 to be freely adjustable while holding the same. The magnetic-force generating part 11 is a permanent magnet, such as a neodymium magnet, formed into a columnar shape. The compressed-air supply part 12 is a disk-shaped member with a through-hole 123 formed in the center. The magnetic-force generating part 11 is fitted into the through-hole 123. One end surface 121 of the compressed-air supply part 12 and one end surface 111 of the magnetic-force generating part 11 fitted into the through-hole 123 together constitute a support surface 10 that faces the surface of the mating member contactlessly.

Description

  The present invention relates to a hydrostatic gas bearing that forms a gas layer in a gap with a relatively moving counterpart member and supports the counterpart member via the gas layer, and is particularly resistant to load fluctuations and is small in size. -It relates to a static pressure gas bearing structure that enables weight reduction.

  Patent Document 1 discloses a hydrostatic gas bearing that can stably support a light-weight support object in a non-contact manner. The hydrostatic gas bearing has a first and second porous surfaces each having a large number of pores formed on a support surface facing the object to be supported in a non-contact manner, and a second surface with respect to the first porous surface. And an end face of the partition wall that separates the porous surface. A compressed air supply pump for discharging compressed air from the opening is connected to each pore of the first porous surface, and air is sucked into the opening into each pore of the second porous surface. An air suction pump is connected. Further, the second porous surface and the first porous surface are substantially flush with each other.

  With such a structure, the hydrostatic gas bearing described in Patent Document 1 discharges compressed air from the first porous surface by the compressed air supply pump and air to the second porous surface by the air suction pump. Even if it is a lightweight support object, it can be stably supported in a non-contact manner by the balance between the suction and the weight of its own weight or the support object.

JP 2005-214290 A

  However, since the static pressure gas bearing described in Patent Document 1 draws the support target to the support surface by sucking air into the second porous surface, the support target is brought to the support surface with a force higher than atmospheric pressure. It cannot be drawn. For this reason, the static pressure gas bearing described in Patent Document 1 has low rigidity. For example, when an external force is applied to the support target or the static pressure gas bearing and a load fluctuation occurs, the support state of the support target may become unstable. There is.

  Moreover, in the static pressure gas bearing described in Patent Document 1, for air suction for sucking air into the second porous surface, separately from the compressed air supply pump for discharging compressed air from the first porous surface. A pump is also required. For this reason, when the static pressure gas bearing is used in an apparatus such as an air slide apparatus, the entire apparatus using the static pressure gas bearing becomes large and heavy.

  The present invention has been made in view of the above circumstances, and the object thereof is less susceptible to load fluctuations due to external force and the like, and therefore, the stability of the support state is high, and the mounted device is reduced in size and weight. An object of the present invention is to provide a static pressure gas bearing structure that enables this.

  In order to solve the above-mentioned problems, in the present invention, in a static pressure gas bearing structure, a magnetic force that generates a magnetic force in a support means that has a support surface that faces a relatively moving counterpart member that is a support target in a non-contact manner. A generating member and a compressed gas supply unit for discharging the compressed gas are provided, and a magnetic member is used as a mating member that forms an air layer between the supporting surface and the generating member.

For example, the present invention is a static pressure gas bearing structure having a support means having a support surface that faces a relatively moving counterpart member in a non-contact manner,
The counterpart member is a magnetic member,
The support means is
Magnetic force generating means for generating a magnetic force;
Compressed gas supply means for supplying compressed gas to a gap between the counterpart member and the support surface.

  According to the present invention, a magnetic member is used as the counterpart member of the static pressure gas bearing, and the magnetic member is made relative to the support surface of the support means of the static pressure gas bearing by the magnetic force generated by the magnetic force generation means. To draw. For this reason, as compared with the case of the static pressure gas bearing using the air suction means in which the drawing force is limited to the atmospheric pressure or less as the means for drawing the mating member, it is possible to reduce the influence on the sudden load fluctuation. A static pressure gas bearing having rigidity can be realized. For this reason, even if a sudden load fluctuation occurs in the counterpart member or the static pressure gas bearing itself, stable relative motion between the static pressure gas bearing and the counterpart member can be maintained. Further, since a gas suction pump is not required, the entire apparatus equipped with the static pressure gas bearing can be reduced in size and weight.

1A and 1B are external views of an air bearing 1 according to an embodiment of the present invention. 2A and 2B are a front view and a rear view of the air bearing 1 shown in FIG. 3A is a right side view of the air bearing 1 shown in FIG. 2A, and FIG. 3B is an AA cross-sectional view of the air bearing 1 shown in FIG. 2A. FIG. 4 is a view for explaining the operating principle of the air bearing 1 according to the embodiment of the present invention.

  Embodiments of the present invention will be described below with reference to the drawings.

  1A and 1B are external views of an air bearing 1 according to an embodiment of the present invention. 2 (A) and 2 (B) are a front view and a rear view of the air bearing 1 shown in FIG. 1, and FIG. 3 (A) is a right side view of the air bearing 1 shown in FIG. 2 (A). FIG. 3B is a cross-sectional view taken along the line AA of the air bearing 1 shown in FIG.

  As shown in the figure, an air bearing 1 according to the present embodiment includes a support surface 10 that faces a relatively moving counterpart member that is a support target, and a magnetic force generator 11 that is a means for generating a magnetic force. And a support 18 having a compressed air supply unit 12 which is disposed around the magnetic force generation unit 11 and discharges compressed air. Further, the air bearing 1 includes a base plate 13 to which a support 18 is attached, and a ball joint 14 that holds the air bearing 1 in a swingable manner.

  The magnetic force generator 11 is a permanent magnet formed in, for example, a cylindrical shape, and for example, a neodymium magnet is used. In the present embodiment, one columnar permanent magnet is used as the magnetic force generator 11, but the shape and number of permanent magnets can be changed as appropriate. For example, a prismatic permanent magnet may be used, or a plurality of through holes 123 may be formed in the center of a compressed air supply unit 12 described later, and the permanent magnets may be fitted into these through holes 123, respectively.

  The compressed air supply unit 12 is a disk-like member in which a through hole 123 connected from one end surface 121 to the other end surface 122 is formed in the center, and the magnetic force generation unit 11 is fitted into the through hole 123.

  One end surface 121 of the compressed air supply unit 12 is a member (hereinafter referred to as a support target) that moves relative to the air bearing 1 together with the one end surface 111 of the magnetic force generation unit 11 fitted in the through hole 123. A support surface 10 that faces the surface in a non-contact manner is configured. In addition, an annular groove 124 surrounding the through hole 123 (that is, the magnetic force generator 11) is formed on one end surface 121, and a compressed air discharge port 125 by a self-contained throttle is formed at the groove bottom of the groove 124. Many are formed at equal intervals along the circumferential direction of the groove 124.

  On the other end surface 122 of the compressed air supply unit 12, an annular groove 126 connected to a plurality of compressed air discharge ports 125 formed on one end surface 121 is formed as a compressed air supply path 126. An O-ring groove 127 is formed on the outer edge of the compressed air supply path 126, and an O-ring 17 for preventing air leakage from the compressed air supply path 126 is accommodated in the O-ring groove 127. The Further, a screw hole 127 to which a hexagon socket head bolt 15 for fixing the compressed air supply unit 12 to the base plate 13 is fastened is formed on the other end surface 122 of the compressed air supply unit 12.

  The base plate 13 is a disk-shaped member having substantially the same outer diameter as that of the compressed air supply unit 12, and is a countersink connected from one end surface 131 to the other end surface 132 at a position corresponding to the screw hole 127 of the compressed air supply unit 12. A hole 133 is formed. With the other end surface 132 of the base plate 13 in contact with the other end surface 122 of the compressed air supply unit 12, the hexagon socket head bolt 15 is inserted into the counterbore hole 133 and the screw hole 127 of the compressed air supply unit 12 is inserted. The compressed air supply unit 12 is fixed to the base plate 13 by being screwed together. At this time, the other end surface 112 of the magnetic force generation unit 11 fitted in the through hole 123 of the compressed air supply unit 12 may be bonded to the other end surface 132 of the base plate 13 with an adhesive.

  One end face 131 of the base plate 13 is formed with a screw hole 134 to which a hexagon socket head bolt 16 for fixing the ball joint 14 to the base plate 13 is fastened.

  The other end surface 132 of the base plate 13 is in contact with the O-ring 17 in the O-ring groove 127 formed on the outer edge of the compressed air supply path 126 of the compressed air supply unit 12. Thereby, the compressed air filled in the compressed air supply path 126 of the compressed air supply unit 12 is in a region other than the compressed air discharge port 125 of the compressed air supply unit 12, that is, the other end surface 122 of the compressed air supply unit 12. This prevents leakage from the contact portion with the other end surface 132 of the base plate 13 to the outside.

  Further, the base plate 13 is formed with a ventilation path 137 connected to the compressed air supply path 126 of the compressed air supply unit 12. The opening 138 of the ventilation path 137 is formed in the side surface 136 of the base plate 13 and is connected to a tube of a compressed air supply pump (not shown). As a result, the compressed air from the compressed air supply pump is supplied to the compressed air supply path 126 of the compressed air supply section 12 through the ventilation path 137 and is directed from the compressed air discharge port 125 of the compressed air supply section 12 to the counterpart member. Erupt.

  The ball joint 14 slides on a ball stud 141 having a ball head 142, a ball socket 143 that rotatably accommodates the ball head 142, a fixed plate 144 formed integrally with the ball socket 143, and the air bearing 1. And a fixing nut 145 for fixing to a base such as the plate 3 (see FIG. 4).

  The ball stud 141 includes a stud portion 149 in which a male screw portion 148 is formed, and a ball head 142 formed integrally with one end surface 1481 of the stud portion 148. A hexagon hole 1483 for a hexagon wrench is formed in the other end surface 1482 of the stud portion 148. Further, a flange 1494 protruding from the outer peripheral surface is formed on the outer periphery of the stud portion 149 on the ball head 142 side (between the male screw portion 148 and the ball head 142). Before the air bearing 1 is attached to the base of the slide plate 3 or the like, the fixing nut 145 is screwed into the male screw portion 148 of the stud portion 149 until it comes into contact with the flange 1494. When the air bearing 1 is attached to the base of the slide plate 3 or the like, the screw portion 148 of the stud portion 149 is screwed into the screw hole 133 formed in the base of the slide plate 3 or the like, and then the hexagonal hole 1488 is hexagonal. While inserting the wrench to prevent the rotation of the stud portion 149, the fixing nut 145 is rotated until it comes into contact with the base of the slide plate 3 or the like. Thereby, the air bearing 1 is attached to the base such as the slide plate 3.

  The ball socket 143 is formed as follows, for example. That is, the ball head 142 of the ball stud 141 is inserted into the cylindrical member integrally formed with the fixing plate 144 so that one end surface is closed by the fixing plate 144. In this state, the opening side of the cylindrical member is inserted. Can be tightened. A top 1431 is disposed in the ball socket 143, and the ball head 142 accommodated in the ball socket 143 is supported by the top 1431.

  A through hole 1441 for inserting a bolt is formed in the fixing plate 144 at a position corresponding to the screw hole 134 of the base plate 13. The ball joint 14 is attached to the base plate 13 by inserting the hexagon socket head bolt 16 into the through hole 1441 and screwing the hexagon socket head bolt 16 into the screw hole 134 of the base plate 13.

  Next, the operating principle of the air bearing 1 having the above structure will be described. FIG. 4 is a view for explaining the operating principle of the air bearing 1 according to the embodiment of the present invention. In this figure, the case where the air bearing 1 is used as an air bearing that slides in a non-contact manner on the fixed rail 2 of the air slide device is illustrated.

  The fixed rail 2 to be supported by the air bearing 1 is made of a magnetic material. The slide plate 3 serving as a base to which the air bearing 1 is attached is formed with a screw hole 33 for the ball stud 141 connected from one end surface 31 to the other end surface 32.

  The ball stud 141 of the air bearing 1 is screwed into the screw hole 33 from one end surface 31 side of the slide plate 3, and the hexagon hole 1483 of the end surface 145 of the ball stud 141 is inserted into the hexagon hole 1483 from the other end surface 32 side of the slide plate 3. Insert a hexagon wrench not shown. Accordingly, the fixing nut 145 is rotated until it contacts the one end surface 31 of the slide plate 3 while preventing the ball stud 141 from rotating together. Thereby, the air bearing 1 is attached to the slide plate 3.

  When the air bearing 1 attached to the slide plate 3 is brought close to the fixed rail 2 so that the support surface 10 of the air bearing 1 faces the surface 21 of the fixed rail 2, the air bearing 1 is moved by the magnetic force m of the magnetic force generator 11. It is attracted to the fixed rail 2. As a result, the support surface 10 of the air bearing is attracted to the surface 21 of the fixed rail 2. In this state, when compressed air is supplied to the ventilation path 137 from the opening 138 provided on the side surface 136 of the base plate 13 by a compressed air supply pump (not shown), the inside of the compressed air supply path 126 of the compressed air supply unit 12 is compressed. The air is filled with air, and the compressed air a is discharged from the plurality of compressed air discharge ports 125 toward the surface 21 of the fixed rail 2. As a result, the air bearing 1 is separated from the fixed rail 2 and positioned at a position where the pressure of the compressed air a, the weight of the slide plate 3 including the air bearing 1 and the like, and the magnetic force m of the magnetic force generator 11 are balanced. . Thus, the load from the slide plate 3 and its load is supported without contact with the fixed rail 2, and the slide plate 3 is slidably held along the fixed rail 2.

  At this time, the ball joint 14 supplies the base plate 13 and the compressed air in the direction d around the center of the ball head 142 so as to keep the gap t between the support surface 10 of the air bearing 1 and the surface 21 of the fixed rail 2 uniform. The part 12 and the magnetic force generation part 11 are swung together to adjust the inclination of the support surface 10 with respect to the ball stud 141.

  The embodiment of the present invention has been described above.

  According to the present embodiment, the magnetic object m (the fixed rail 2 in the example of FIG. 4) is attracted relatively to the support surface 10 of the air bearing 1 by the magnetic force m of the magnetic force generator 11. Therefore, the support surface 10 of the air bearing 1 is moved with a larger force than when the support target is relatively pulled by air suction (that is, when the force for pulling the support target is limited to atmospheric pressure or less). It is possible to attract. For this reason, the rigidity with respect to the load fluctuation of the air bearing 1 can be further increased, and the support target or the air bearing 1 (specifically, a base to which the air bearing 1 is attached, such as the slide plate 3 shown in FIG. 4). ) Even if the load fluctuates, it can stably move relative to the support target. Moreover, since an air suction pump is not required, the entire apparatus using the air bearing 1 can be reduced in size and weight. Furthermore, as shown in FIG. 4, when the air bearing 1 is used in an air slide device, it is possible to accurately stop at a desired position on the fixed rail 2 of the slide plate 3, thereby improving the positioning function. it can.

  Moreover, in this Embodiment, the magnetic bearing 11 which arrange | positions the magnetic force generation part 11 which generate | occur | produces the force which draws the air bearing 1 and a support object relatively relatively in the center, and surrounds the outer peripheral side of this magnetic force generation part 11 is surrounded. The compressed air supply unit 12 that generates a force that relatively separates the support target and the support target is disposed. For this reason, for example, even when a force in the direction of tilting the support surface 10 with respect to the support target is applied to the air bearing 1, the air bearing 1 and the support are supported so as to eliminate the tilt in the outer peripheral region of the support surface 10. Since a force that relatively separates the object is applied, the relative movement with respect to the support object can be further stabilized while maintaining the gap t between the support surface 10 and the surface of the support object.

  In the present embodiment, a permanent magnet is used for the magnetic force generator 11. When the support target is relatively pulled by air suction, when the pump stops due to a failure or the like, the force that relatively pulls the support target and the air bearing together with the force that relatively pulls the support target and the air bearing does not work. Therefore, there is a possibility that the support target is dropped from the air bearing or the air bearing is dropped from the support target. On the other hand, according to the present embodiment, since the magnetic force m that relatively draws the air bearing 1 and the support object is constantly acting by the permanent magnet, even if the compressed air supply pump stops, the air Since the bearing 1 and the support target are adsorbed to each other, the air bearing 1 can be held on the support target or the support target can be held on the air bearing 1 without taking any special drop-off prevention measures.

  In the present embodiment, the ball joint 14 adjusts the inclination d of the support surface 10 with respect to the ball stud 141 so that the gap t between the support surface 10 of the air bearing 1 and the surface of the support target is kept uniform. For example, in FIG. 4, the air bearing 1 can be automatically aligned with respect to the inclination of the surface 21 of the fixed rail 2.

  In addition, this invention is not limited to said embodiment, Many deformation | transformation are possible within the range of the summary.

  For example, in the above embodiment, the compressed air supply unit 12 in which a large number of compressed air discharge ports 125 are formed by a self-contained throttle is used, but the present invention is not limited to this. Instead of the compressed air supply unit 12, for example, a compressed air supply unit in which a large number of compressed air discharge ports such as an orifice restrictor and a surface restrictor are formed on the surface constituting the support surface 10 may be used. Alternatively, a compressed air supply unit in which a porous sintered layer connected to the compressed air supply path 126 is formed on the surface constituting the support surface 10 may be used.

  In the above embodiment, a permanent magnet is used as the magnetic force generation unit 11, but an electromagnet may be used as the magnetic force generation unit 11.

  Moreover, in said embodiment, although the ball joint 14 is used as an alignment mechanism of the air bearing 1, this invention is not limited to this. Others may be used as long as the inclination of the support surface 10 can be automatically adjusted so as to keep the gap t between the support surface 10 of the air bearing 1 and the support target uniform. For example, the gap t between the support surface 10 of the air bearing 1 and the support target may be kept uniform by attaching the air bearing 1 to the base via an elastic body.

  In the above embodiment, as an apparatus using the air bearing 1, the air bearing 1 attached to the base (slide plate 3 in FIG. 4) is mounted on the magnetic support target (fixed rail 2 in FIG. 4). The present invention has been described by taking an air slide device as an example, but in the present invention, an air layer is formed in a gap with the support target, such as a device in which the base is fixed and the support target moves in a non-contact manner on the air bearing 1, Of course, any apparatus using an air bearing that supports the load in the gap direction with the object to be supported is applicable.

  In the above-described embodiment, the air bearing 1 is formed as an example in which an air layer is formed in a gap with a relatively moving counterpart member to be supported, and the counterpart member is supported via the air layer. The present invention is widely applicable to hydrostatic gas bearings in which a gas layer is formed in a gap with a mating member and the mating member is supported via the gas layer.

  1: Air bearing, 2: Fixed rail, 3: Slide plate, 10: Support surface, 11: Magnetic force generation part, 12: Compressed air supply part, 13: Base plate, 14: Ball joint, 15, 16: Hexagon socket head cap screw , 17: O-ring, 18: support, 31, 32: end surface of the slide plate 3, 33: screw hole of the slide plate 3, 111, 112: end surface of the magnetic force generation unit 11, 121, 122: compressed air supply unit 12 123: Through hole of compressed air supply unit 12 124: Groove of compressed air supply unit 12 125: Compressed air discharge port 126: Compressed air supply path 127: Screw hole of compressed air supply unit 12 : Groove for O-ring of compressed air supply unit 12, 131, 132: End surface of base plate 13, 133: Countersink hole of base plate 13, 134: Base plate 3 screw holes, 136: side surface of the base plate 13, 137: air passage of the base plate 13, 138: opening of the air passage 137, 141: ball stud, 142: ball head, 143: ball socket, 144: fixing plate, 145: Nuts for fixing ball stud 141, 148: male screw portion of ball stud 141, 149: stud portion of ball stud 141, 1431: piece, 1441: screw hole of fixing plate 144, 1491, 1492: end surface of stud portion 149, 1493: Hexagon socket of stud 149, 1494: Flange of stud 149

Claims (6)

A hydrostatic gas bearing structure having a support means having a support surface facing non-contact with a relatively moving counterpart member,
The counterpart member is a magnetic member,
The support means is
Magnetic force generating means for generating a magnetic force;
A hydrostatic gas bearing structure comprising compressed gas supply means for supplying compressed gas to a gap between the counterpart member and the support surface. The static pressure gas bearing structure according to claim 1,
The hydrostatic gas bearing structure, wherein the magnetic force generating means is disposed at the center of the support surface, and the compressed gas supply means is disposed so as to surround an outer peripheral side of the magnetic force generating means. The static pressure gas bearing structure according to claim 1 or 2,
The magnetic force generating means is a magnet,
The compressed gas supply means is a plate-like member in which at least one compressed gas discharge port is formed on one end face, and an insertion hole for the magnetic force generating means is formed in the center of the one end face.
The support surface is
A static pressure gas bearing structure, comprising an end face of the magnet and the one end face of the plate-like member. The static pressure gas bearing structure according to claim 3,
The magnet is made of at least one permanent magnet. The static pressure gas bearing structure according to any one of claims 1 to 4,
A static pressure gas bearing structure, further comprising an alignment means for maintaining a uniform gap between the support surface and the mating member. The static pressure gas bearing structure according to claim 5,
The alignment means includes
A static pressure gas bearing structure, wherein the static pressure gas bearing is a ball joint for mounting the static pressure gas bearing to the base at any angle.

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