JP2008082356A - Static pressure gas bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mass-producible, inexpensive static pressure gas bearing. <P>SOLUTION: This static pressure gas bearing is equipped with: a resin bearing member 2 in which a cylindrical through hole 2a is extendingly formed in the axial direction, having a plurality of air blowout ports 2c on the inner face of the through hole 2a, and an air supply groove 2c on the outer face of the through hole 2a communicating with the air blowout ports 2b; and a base body 3 bonded to the resin bearing member 2 to cover the air supply groove 2c and having an air supply port 3b on the outer face thereof for communicating with the air supply groove 2c. The resin bearing member 2 is formed by injection molding, and the structure of the base body 3 is simple, such that the static pressure gas bearing 1 can be assembled just by bonding the base body 3 to cover the resin bearing member 2. An air supply groove 3d may be provided on the side of the base body 3. In the case the resin bearing member 2 and the base body 3 are cylindrical, the resin bearing member 2 is preferably inserted inside the base body 3 by temporarily decreasing the outer diameter of the resin bearing member 2 or temporarily increasing the inner diameter of the base body 3 so that the resin bearing member 2 has a larger outer diameter than the inner diameter of the base body 3. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a static pressure gas bearing, and in particular, is formed in a cylindrical shape and can be used as a bearing that allows a shaft to be inserted therein to perform a rotational motion, a rocking motion, or a reciprocating motion. The present invention relates to a static pressure gas bearing.

  Conventionally, a static pressure gas bearing is a bearing capable of realizing ultra-low friction, ultra-high accuracy, and ultra-high-speed motion. In the case of cylindrical radial bearings that perform ultra-precise measurements, etc., there are applications such as inserting a shaft inside to perform ultra-high speed rotation. There are porous throttles, surface throttles, orifice throttles, self-contained throttles, etc., as the types of throttles at the air outlet of this static pressure gas bearing, and they were used while adjusting the load capacity and rigidity according to the application. .

  For example, Patent Document 1 discloses a static bearing having a carbon graphite bearing member having a porous diaphragm and an alumina ceramic holding member for holding the bearing member as a radial bearing that achieves ultrahigh rigidity and high accuracy. Pressure gas bearings have been proposed.

JP 2006-112497 A

  Although the above-mentioned conventional static pressure gas bearings and the like can achieve ultra-low friction, ultra-high precision and ultra-high-speed motion, high-strength metals and ceramics are mainly used as bearing materials, and high-precision Since it is necessary to perform grinding finishing etc., there was a problem that mass production was difficult and the price increased. For this reason, currently only high-priced hydrostatic gas bearings are available on the market, and even when ultra-low friction, ultra-high accuracy and ultra-high-speed motion are not required, high-priced hydrostatic gas bearings must be selected. Therefore, static pressure gas bearings have not been widely used.

  Then, this invention was made | formed in view of the problem in the said conventional static pressure gas bearing, Comprising: It aims at providing the cheap static pressure gas bearing which can be utilized in various field | areas.

  In order to achieve the above object, the present invention is a static pressure gas bearing, wherein a through hole is formed in a cylindrical shape extending in an axial direction, and a plurality of air outlets are provided on an inner surface of the through hole, and the plurality of air outlets are provided on an outer surface. A resin bearing member having an air supply groove communicating with the air outlet, and a base body having an air supply opening connected to the resin bearing member so as to cover the air supply groove and communicating with the air supply groove on the outer surface; It is characterized by providing.

  According to the present invention, the resin bearing member constituting the static pressure gas bearing can be formed by injection molding using a mold, and mechanical processing is not required, and the structure of the base body Since the static pressure gas bearing can be assembled by simply joining the resin bearing member so as to cover the resin bearing member only by having an air supply port communicating with the resin bearing member, mass production of the static pressure gas bearing becomes possible. An inexpensive static pressure gas bearing can be provided.

  The present invention also relates to a static pressure gas bearing, wherein a through hole is formed in a cylindrical shape extending in the axial direction, and a resin bearing member having a plurality of air outlets on the inner surface of the through hole, and the resin bearing An air supply groove that is joined to the resin bearing member so as to cover the member, communicates with the plurality of air outlets on the joint surface with the resin bearing member, and air supply communicates with the air supply groove on the outer surface. And a base having a mouth. As a result, as in the above-described invention, mass production of static pressure gas bearings is possible, and an inexpensive static pressure gas bearing can be provided.

  In the static pressure gas bearing, the resin bearing member is made of at least one of polyphenylene sulfide resin, polyether sulfone resin, polyether ether ketone resin, liquid crystal polymer resin, glass fiber, carbon fiber, or inorganic filler. It can be formed of a reinforced reinforcing material-containing polyphenylene sulfide resin, polyether sulfone resin, polyether ether ketone resin, or liquid crystal polymer resin, and can be a resin bearing member having high strength. Moreover, since the resin bearing members formed of these resins are excellent in slidability and have self-lubricating properties, there is little risk of damage even if they come into contact with other members, and the safety is high.

  The substrate is also made of polyphenylene sulfide resin, polyether sulfone resin, polyether ether ketone resin or liquid crystal polymer resin, or polyphenylene containing a reinforcing material reinforced with at least one of glass fiber, carbon fiber, or inorganic filler. It may be formed of a sulfide resin, a polyether sulfone resin, a polyether ether ketone resin, or a liquid crystal polymer resin, or may be formed of a metal other than those synthetic resins.

  In the static pressure gas bearing, the resin bearing member and the substrate may be bonded by ultrasonic bonding, bonding by high frequency induction heating, or bonding via an adhesive. The bonding strength can be improved, and deformation of each member due to air supply and air leakage can be easily prevented.

  In the static pressure gas bearing, the resin bearing member and the base body can be formed in a cylindrical shape, and a static pressure gas bearing in which two parts of the inner and outer rings are combined can be configured.

  In the static pressure gas bearing, the resin bearing member has an outer diameter larger than the inner diameter of the base, and the outer diameter of the resin bearing member is temporarily reduced, or the inner diameter of the base is reduced. The resin bearing member and the base may be assembled by inserting the resin bearing member inside the base in a state where the diameter is temporarily expanded. As a method of temporarily reducing the outer diameter of the resin bearing member or temporarily expanding the inner diameter of the base, a method of deforming the resin bearing member or the base by heat, etc. can be used. According to the above configuration, after the resin bearing member is inserted inside the base, the outer diameter of the resin bearing member is increased or the inner diameter of the base is reduced. Both of them can be firmly pressed by the residual stress between them, and it is possible to suppress the occurrence of displacement and deformation due to the supply air pressure, and other air leaks.

  As described above, according to the present invention, it is possible to provide an inexpensive static pressure gas bearing that can be mass-produced.

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

  1 to 4 show an embodiment of a static pressure gas bearing according to the present invention, and the static pressure gas bearing 1 includes a resin bearing member 2 and a base 3.

  As shown in FIG. 2, the resin bearing member 2 is formed in a cylindrical shape having a through hole 2a extending in the axial direction at the center, and has a diameter of about 0.2 to 0.4 mm on the inner peripheral surface of the through hole 2a. A plurality of self-drawn air outlets 2b are provided, and two air supply grooves 2c having a rectangular cross section and an annular shape in front view are provided on the outer peripheral surface and communicated with each of the air outlets 2b. The resin bearing member 2 can be formed using a polyphenylene sulfide resin, a polyether sulfone resin, a polyether ether ketone resin, or a liquid crystal polymer resin, and the resin is made of glass fiber, carbon fiber, or inorganic filler. It is preferable to mix and strengthen at least one. By using these resins, the strength of the resin bearing member 2 can be increased, and since the resin bearing member 2 is excellent in slidability and also has self-lubricating properties, it is temporarily in contact with other members. Even if it happens, there is little risk of damage and safety is high.

  2 shows a configuration in which eight air outlets 2b arranged in parallel at equal intervals along the shape of the resin bearing member 2 are connected by one air supply groove 2c, and two sets of them are provided. Although shown, the numbers of the air outlets 2b and the air supply grooves 2c can be changed as appropriate according to the weight and application of the article to be supported. Further, the air outlet 2b communicates with the air supply groove 5c of the resin bearing member 5 through the air passage 5b, as shown in FIG. 3, in addition to the self-contained throttle shape as shown in FIG. A so-called orifice-shaped air outlet having an air outlet 5a having a diameter larger than that of the air passage 5b may be used.

  As shown in FIG. 4, the base 3 is formed in a cylindrical shape having a through hole 3a extending in the axial direction at the center, and is connected to the air supply groove 2c of the resin bearing member 2 shown in FIG. And an internal thread portion 3c formed on the inner peripheral surface of the air supply port 3b. As shown in FIG. 1, the resin bearing member 2 is inserted into the through hole 3 a of the base 3, but the base 3 has a through hole 3 a in a state before the resin bearing member 2 is inserted. Is formed to be slightly smaller than the outer diameter of the resin bearing member 2.

  Similarly to the resin bearing member 2, the substrate 3 is made of polyphenylene sulfide resin, polyether sulfone resin, polyether ether ketone resin, liquid crystal polymer resin, or synthetic resin thereof, glass fiber, carbon fiber, or inorganic material. It can be formed of a reinforced synthetic resin mixed with at least one filler.

  Next, the manufacturing method of the static pressure gas bearing 1 having the above configuration will be described with reference to the drawings.

  The entire resin bearing member 2 shown in FIG. 2 is injection-molded using a mold. The air outlet 2b, the air supply groove 2c, and the air passage 2d are preferably formed by injection molding. However, when the number of production of the static pressure gas bearings 1 and the number of the air outlets 2b are small, they are formed by machining. May be.

  The base 3 shown in FIG. 4 is also formed by injection molding in the same manner as the resin bearing member 2. Even when the air supply port 3b and the female screw portion 3c of the base 3 are formed, it is preferably formed by injection molding as in the case of the air outlet 2b of the resin bearing member 2, but may be formed by machining. Good.

  After the resin bearing member 2 and the base 3 are formed, the resin bearing member 2 and the base 3 are joined. At this time, the resin bearing member 2 is inserted into the through hole 3a of the base 3 using a cold fit. It is preferable to install. That is, prior to inserting the resin bearing member 2 into the through hole 3a of the base 3, the resin bearing member 2 is cooled to temporarily reduce the outer diameter of the resin bearing member 2, and in this state The resin bearing member 2 is inserted into the through hole 3 a of the base 3. After that, when the resin bearing member 2 is exposed to room temperature, the outer diameter of the resin bearing member 2 is expanded, so that both are firmly pressed by the residual stress between the resin bearing member 2 and the base 3. Therefore, it is possible to suppress the occurrence of misalignment and deformation due to the supply air pressure, and other air leaks.

  Further, when joining the resin bearing member 2 and the base 3, in addition to the cooling fit, as shown in FIG. 1, the portions 10 on both sides sandwiching the air outlet 2 b are connected to the resin bearing member 2. It is preferable to perform ultrasonic or high frequency induction heating in a ring shape along the shape, or to join using an adhesive. As a result, the bonding strength between the resin bearing member 2 and the base 3 can be further improved, and displacement and deformation can be further suppressed.

  Next, the operation of the hydrostatic gas bearing 1 shown in FIGS. 1 to 4 will be described with reference to FIG.

  A plug 7 a attached to the end of a resin tube 7 for supplying air to the static pressure gas bearing 1 is screwed into the female screw portion 3 c of the base 3, and air is supplied to the air supply port 3 b through the resin tube 7. Supply. The air taken in from the air supply port 3b is ejected from the respective air outlets 2b to the inside (in the direction of the arrow) of the static pressure gas bearing 1 through the air supply groove 2c and the air passage 2d of the resin bearing member 2. Thereby, the axis | shaft 9 located in the through-hole 2a of the static pressure gas bearing 1 can be supported via an air layer, and the axis | shaft 9 can be rotated at high speed.

  As described above, according to the present embodiment, the resin bearing member 2 and the base body 3 can be formed by injection molding using a mold, and mechanical processing is not required, and the base body Since the structure 3 also has an air supply port 3b communicating with the air supply groove 2c of the resin bearing member 2, the static pressure gas bearing 1 can be assembled only by joining so as to cover the resin bearing member 2. The static pressure gas bearing 1 can be mass-produced at a low cost.

  In the above embodiment, both the resin bearing member 2 and the base 3 are cylindrical radial static pressure gas bearings. However, as shown in FIG. The bearing member 2 can be formed in a cylindrical shape having a columnar through-hole 2a, and the base body 3 can be formed in a rectangular tube shape surrounding the resin bearing member 2, as shown in FIG. The resin bearing member 2 can also be formed in a rectangular tube shape having a cylindrical through hole 2a, and a shaft can be inserted into the through hole 2a to perform high-speed rotation or the like.

  Further, as shown in FIG. 6C, the resin bearing member 2 is formed in a rectangular tube shape having a prismatic through hole 2a, and the base body 3 is also formed in a rectangular tube shape surrounding the resin bearing member 2. It is also possible to adopt a configuration in which a shaft is inserted through the prismatic through hole 2a to perform reciprocating motion. In FIG. 6C, either the resin bearing member 2 or the base 3 is formed in a cylindrical shape, or both are cylindrical in a state where the resin bearing member 2 has a prismatic through hole 2a. It can also be formed.

  In the above embodiment, as shown in FIG. 1 and the like, the air supply groove 2 c is formed in the resin bearing member 2, but the air supply groove may be formed in the base 3. For example, as shown in FIG. 7, an air passage 2d having a uniform cross section penetrating from the outer surface of the resin bearing member 2 to the air outlet 2b of the inner surface 2e of the through hole 2a is formed, and the inner peripheral surface of the base 3 In addition, the air supply groove 3d may be formed so as to communicate with the air outlet 2b via the air passage 2d.

  In the static pressure gas bearing 1 shown in FIGS. 1 to 4, since the air supply groove 2c is provided in the resin bearing member 2, the base 3 is formed in a cylindrical shape having only the air supply port 3b. In addition, as shown in FIG. 2, since the thickness d1 from the bottom surface of the air supply groove 2c to the inner surface 2e of the through hole 2a is thin, the air outlet 2b and the air passage 2d are provided. It can be formed easily. When the air outlet 2b has an orifice shape as shown in FIG. 3, only the orifice portion may be machined separately.

  On the other hand, in the static pressure gas bearing 1 shown in FIG. 7, since the air supply groove 3d is provided on the base 3 side, the distance from the air outlet 2b to the air supply groove 3d, that is, the thickness of the resin bearing member 2 is provided. The thickness d2 becomes thick, and the strength around the air inlet 3d can be increased.

  Furthermore, in the said embodiment, although the base | substrate 3 is formed with the synthetic resin, you may form the base | substrate 3 with metals, such as aluminum other than a synthetic resin, and cast the whole base | substrate 3 using the casting_mold | template. Thereafter, the internal thread portion 3c may be machined.

  In the above-described embodiment, a cold fit is used for joining the resin bearing member 2 and the base 3. However, in addition to the cool fit, the base 3 is heated to pass through the holes 3 a of the base 3. Alternatively, shrink fitting that temporarily expands the inner diameter of the resin or a method of temporarily deforming the resin bearing member 2 or the base body 3 by applying pressure may be used.

BRIEF DESCRIPTION OF THE DRAWINGS It is an assembly drawing which shows one Embodiment of the static pressure gas bearing concerning this invention, Comprising: (a) is a front view, (b) is the sectional view on the AA line of (a). It is a figure which shows the resin-made bearing members of the static pressure gas bearing shown in FIG. 1, (a) is a top view, (b) is a front view, (c) is a BB sectional drawing of (b). is there. It is sectional drawing which shows the other example of the air blower outlet of the resin-made bearing members concerning this invention. It is a figure which shows the base | substrate of the static pressure gas bearing shown in FIG. 1, Comprising: (a) is a top view, (b) is a front view, (c) is CC sectional view taken on the line of (b). It is sectional drawing for demonstrating the usage example of the static pressure gas bearing shown in FIG. It is a front view which shows other embodiment of the static pressure gas bearing concerning this invention. It is an assembly drawing which shows other embodiment of the static pressure gas bearing concerning this invention, Comprising: (a) is a front view, (b) is DD sectional drawing of (a).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Static pressure gas bearing 2 Resin-made bearing member 2a Through-hole 2b Air blower outlet 2c Air supply groove 2d Air passage 2e Inner surface 3 Base | substrate 3a Through-hole 3b Air supply port 3c Female thread part 3d Air supply groove 5 Resin bearing member 5a Air blower Outlet 5b Air passage 5c Air supply groove 7 Resin tube 7a Plug 9 Shaft 10 Joint

Claims (7)

A resin bearing member having a through hole formed in a cylindrical shape extending in the axial direction, a plurality of air outlets on an inner surface of the through hole, and an air supply groove communicating with the plurality of air outlets on an outer surface;
A hydrostatic gas bearing, comprising: a base member that is joined to the resin bearing member so as to cover the air supply groove and has an air supply port that communicates with the air supply groove on an outer surface. A resin bearing member having a through hole formed in a cylindrical shape extending in the axial direction and having a plurality of air outlets on the inner surface of the through hole;
An air supply groove that is joined to the resin bearing member so as to cover the resin bearing member, communicates with the plurality of air outlets on the joint surface with the resin bearing member, and the air supply groove on the outer surface. A static pressure gas bearing comprising: a base body having an air supply port communicating therewith.   The resin bearing member is made of a polyphenylene sulfide resin, a polyether sulfone resin, a polyether ether ketone resin or a liquid crystal polymer resin, or a polyphenylene containing a reinforcing material reinforced with at least one of glass fiber, carbon fiber, or an inorganic filler. The hydrostatic gas bearing according to claim 1 or 2, comprising a sulfide resin, a polyether sulfone resin, a polyether ether ketone resin, or a liquid crystal polymer resin.   The substrate is a polyphenylene sulfide resin, a polyether sulfone resin, a polyether ether ketone resin or a liquid crystal polymer resin, or a polyphenylene sulfide resin with a reinforcing material reinforced with at least one of glass fiber, carbon fiber, or an inorganic filler, The hydrostatic gas bearing according to claim 1, 2, or 3, wherein the hydrostatic gas bearing is made of a polyether sulfone resin, a polyether ether ketone resin, a liquid crystal polymer resin, or a metal.   5. The static pressure according to claim 1, wherein the resin bearing member and the base are bonded by ultrasonic bonding, bonding by high-frequency induction heating, or bonding through an adhesive. Gas bearing.   The hydrostatic gas bearing according to claim 1, wherein the resin bearing member and the base are cylindrical.   The resin bearing member has an outer diameter larger than the inner diameter of the base, and the outer diameter of the resin bearing member is temporarily reduced, or the inner diameter of the base is temporarily increased. The static pressure gas bearing according to claim 6, wherein the static pressure gas bearing is inserted inside the base in a state.

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