JP2005069871A - Turntable device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a turntable device wherein a turning table is smoothly supported without using a lubricant such as grease. <P>SOLUTION: The table 1 is turned with a pinion 2, made by gear-cutting a shaft part 1b on the downside of a table part 1a, meshing with a rack 4 rectilinearly driven by a linear solenoid 3. The table 1 is radially supported by a support member 5 via a slide bearing 9 with a resin film 9a formed thereon. The table 1 is axially supported by a plurality of balls 7 with their surfaces formed of a resin, the balls being arranged around the shaft part 1b and between the support member 5 and the table part 1a. Thus, the table 1 can be smoothly supported without using the lubricant such as grease. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a turning table device that rotates and positions an object mounted on a table.

  A turning table device that supports a table rotated around a vertical axis by an actuator on a support member on the lower side is applied to various mechanical devices such as robots, semiconductor manufacturing devices, precision machines, machine tools, and the like. It is used for rotational positioning of objects such as mounted workpieces. In this type of swivel table device, a rolling bearing is used for supporting the rotating table to the support member, and in particular, a cross roller bearing that can receive a radial load and an axial load with one bearing is often used. (For example, refer to Patent Document 1).

Japanese Patent Laid-Open No. 2002-341076 (page 3, FIG. 8)

  A rolling bearing such as a cross roller bearing used in the above-described conventional turning table device requires a lubricant such as grease in order to lubricate between the race and the rolling element. However, depending on the mechanical device to which the swivel table device is applied, it may not be possible to use these lubricants due to a slight scattering of lubricants such as grease or usage environments that dislike the generation of steam due to temperature rise. is there.

  Therefore, an object of the present invention is to provide a turning table device that can smoothly support a rotating table without using a lubricant such as grease.

  In order to solve the above-described problems, the present invention provides a rotary table device in which a table rotated around a vertical axis by an actuator is supported on a support member on a lower side, and a shaft portion is provided on the lower side of the table. The shaft portion is supported by a slide bearing having at least a sliding surface made of resin, and a plurality of balls having at least a surface made of resin are placed between the support member and the lower surface of the table. A configuration in which the axial direction of the table is supported by the plurality of balls is used.

  That is, the radial direction of the table is slidably contacted with the lower shaft portion and supported by a slide bearing having at least a sliding surface formed of resin, and the axial direction of the table is defined between the support member and the lower surface of the table. By supporting with a plurality of balls arranged at least on the surface and made of resin, the rotating table can be smoothly supported without using a lubricant such as grease.

  The support member can be manufactured at low cost by forming the support member as a thin press-formed product and forming the annular groove in which the plurality of balls are arranged by press molding.

  Further, the present invention provides a rotary table device in which a table rotated around a vertical axis by an actuator is supported on a support member on a lower side, and a shaft portion is provided on a lower side of the table, and the radial portion of the shaft portion is provided. The direction is supported by a sliding bearing having at least a sliding surface made of resin, and a thrust washer having at least a sliding surface made of resin is inserted around the shaft portion between the support member and the lower surface of the table. A configuration is also adopted in which the axial direction of the table is supported by the thrust washer.

  That is, the radial direction of the table is slidably contacted with the lower shaft portion and supported by a slide bearing having at least a sliding surface formed of resin, and the axial direction of the table is defined between the support member and the lower surface of the table. The rotating table is smoothly supported without using a lubricant such as grease by supporting it with a thrust washer fitted around the shaft portion and having at least a sliding surface made of resin.

  The support member can be manufactured at low cost by forming the support member as a thin press-formed product and forming an annular groove into which the thrust washer is fitted by press forming.

  The resin that forms the sliding surface of the sliding bearing and the resin that forms the surface of the ball or the sliding surface of the thrust washer are heat-resistant resins, so that the swivel table device can be used even in environments where the temperature rises. can do. As the heat resistant resin, a fluorine resin such as polyimide resin, polyamide resin, liquid crystal polyester resin, polyether ketone resin, polyphenylene sulfide resin (PPS), PTFE, or the like can be used.

  The heat-resistant resin is preferably a resin composition in which a solid lubricant and a reinforcing material are appropriately blended. For example, 15 to 40% by mass of a solid lubricant such as PTFE, graphite, and molybdenum disulfide, and glass fibers and carbon fibers. A heat-resistant resin composition containing about 3 to 30% by mass of a reinforcing material such as mineral fiber such as potassium titanate whisker is preferable. The solid lubricant effectively lowers the coefficient of friction of the heat-resistant resin and smoothly rotates the table. In addition, the reinforcing material prevents creep deformation due to load.

  By providing a means for preventing the shaft portion of the table from coming off from the support member, it is possible to prevent the table from falling off due to a large vibration or the like.

  The actuator is linearly driven in the horizontal direction, and the linear motion of the actuator is converted into the rotational motion of the table by the meshing of the rack and pinion. Can be.

  By forming the pinion on the outer periphery of the shaft portion of the table, the number of parts can be reduced.

  The turning table device of the present invention supports the radial direction of the rotating table by a sliding bearing that is slidably contacted with the lower shaft portion and at least the sliding surface is formed of resin, and the axial direction of the table. A plurality of balls arranged around the shaft portion between the support member and the lower surface of the table, at least a surface of which is made of resin, or at least inserted around the shaft portion between the support member and the lower surface of the table, Since the sliding surface is supported by a thrust washer formed of resin, the rotating table can be smoothly supported without using a lubricant such as grease.

  The support member can be manufactured at low cost by forming the support member as a thin press-molded product and forming an annular groove in which the plurality of balls or thrust washers are disposed by press molding.

  By using a heat-resistant resin as the resin for forming the sliding surface of the sliding bearing and the resin for forming the ball surface or the sliding surface of the thrust washer, the swivel table device can be applied even in an environment where the temperature rises. Can do.

  By providing the support member with means for preventing the shaft portion of the table from coming off, it is possible to prevent the table from falling off due to large vibrations or the like.

  The actuator is linearly driven in the horizontal direction, and the linear motion of the actuator is converted into the rotational motion of the table by the engagement of the rack and the pinion. Can be.

  By forming the pinion on the outer periphery of the shaft portion of the table, the number of parts can be reduced.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 6. 1 and 2 show a first embodiment. As shown in FIG. 1, in this turning table device, a table 1 that is a press-formed product of a thin steel plate has a pinion 2 cut on the outer periphery of a shaft portion 1b formed on the lower side of the table portion 1a. The table 1 supported by a support member 5 that is a press-formed product of a thin steel plate is rotated in both directions by meshing of a rack 4 and a pinion 2 that are linearly driven in a horizontal direction by a linear solenoid 3 as an actuator. It has become so.

  In the support member 5, an annular groove 6 is formed around a hole through which the shaft portion 1b of the table 1 is passed, and a plurality of balls 7 supporting the axial direction are arranged in the annular groove 6. Each ball 7 is formed of PPS (including 20% by mass of PTFE and 10% by mass of graphite) which is a heat-resistant resin, and the rolling surfaces 8a and 8b of the ball 7 are concave on the bottom of the annular groove 6 and the lower surface of the table portion 1a. Is formed. As shown in FIG. 2A, the balls 7 are arranged in the annular groove 6 in a total ball state.

  On the inner peripheral side of the inner peripheral vertical wall portion of the annular groove 6 of the support member 5, a ring-shaped slide bearing 9 that supports the shaft portion 1b of the table 1 in the radial direction is press-fitted. This sliding bearing 9 was formed as a sliding surface by forming a coating 9a of a fluororesin (containing 5% by mass of carbon fiber and 5% by mass of inorganic compound powder in PTFE) on the inner peripheral surface of the steel ring. Is.

  An annular pressing plate 10 that presses the support member 5 upward at the bottom of the annular groove 6 to prevent it from coming off is press-fitted into the outer periphery of the shaft portion 1 b of the table 1. Note that a fluororesin film 10 a such as PTFE is formed on the upper surface of the pressing plate 10 that causes a slip between the bottom surface of the annular groove 6.

  FIG. 2B shows a modification of the method for arranging the balls 7. In this modification, a plurality of balls 7 are arranged in the annular groove 6 at intervals by the retainer 11.

  3 and 4 show a second embodiment. This swivel table device has the same basic configuration as that of the first embodiment, and only the support form of the table 1 in the axial direction is different as shown in FIG. In this embodiment, a thrust washer 12 that is in sliding contact with the lower surface of the table portion 1a is fitted in the annular groove 6 of the support member 5 formed by press molding. The thrust washer 12 is formed of PPS which is a heat resistant resin. As shown in FIGS. 4A and 4B, the lower surface side is formed in a trapezoidal shape, the upper surface is formed flat, and the table portion is formed on the entire surface. It is in sliding contact with the lower surface of 1a.

  On the inner peripheral side of the inner peripheral vertical wall portion of the annular groove 6 of the support member 5, a ring-shaped slide bearing 9 that supports the shaft portion 1b of the table 1 in the radial direction is press-fitted. The sliding bearing 9 is formed by forming a fluororesin coating 9a, which is a heat-resistant resin, on the inner peripheral surface of a steel ring. The ring-shaped plain bearing 9 may be integrated with a thrust washer 12.

  5 and 6 are modifications of the thrust washer 12. In the modification shown in FIGS. 5A and 5B, a convex step 12a that is in sliding contact with the lower surface of the table portion 1a is provided on the upper surface at a phase of 120 °, and the sliding resistance of the table 1 is reduced. It is. 6 (a) and 6 (b), the groove 12b into which wear powder generated by sliding with the table 1 is inserted is further provided on the sliding contact surface of each convex step 12a. It has been devised to prevent dispersion.

  In the embodiment described above, the entire ball and thrust washer are formed of resin, but only the surface of the ball and the sliding surface of the thrust washer may be formed of resin. Conversely, the entire sliding bearing may be formed of resin. As the resin for these plain bearings, balls and thrust washers, polyimide resin, polyamide resin, liquid crystal polyester resin, polyether ketone resin, etc. can be used in addition to fluorine resin such as PTFE and PPS.

  Further, the table and the support member are not limited to the thin plate press-formed product as in the embodiment, and may be formed by cutting or forging. Furthermore, the actuator for rotating the table is not limited to the linear solenoid of the embodiment, and other linear actuators, and rotary actuators such as servo motors and stepping motors can be used.

Cutaway front view showing the turning table device of the first embodiment a is a plan view showing the arrangement of the balls in FIG. 1, and b is a plan view showing a modification of the arrangement of a. Notched front view showing a turning table device of the second embodiment a is a plan view showing the thrust washer of FIG. 3, b is a longitudinal sectional view of a a is a plan view showing a modification of the thrust washer of FIG. 4, and b is a longitudinal sectional view of a. a is a plan view showing another modification of the thrust washer of FIG. 4, b is a longitudinal sectional view of a

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Table 1a Table part 1b Shaft part 2 Pinion 3 Linear solenoid 4 Rack 5 Support member 6 Annular groove 7 Ball 8a, 8b Rolling surface 9 Slide bearing 10 Holding plate 9a, 10a Film 11 Retainer 12 Thrust washer 12a Convex step 12b Groove

Claims (8)

  In a turning table device that supports a table rotated around a vertical axis by an actuator on a support member on a lower side, a shaft portion is provided on the lower side of the table, and at least a sliding surface is provided in a radial direction of the shaft portion. A plurality of balls, which are supported by a plain bearing made of resin, are arranged around the shaft portion between the support member and the lower surface of the table, and at least the surface is made of resin. A turntable device characterized by being supported by a plurality of these balls.   The swivel table device according to claim 1, wherein the support member is a press-formed product made of a thin plate, and an annular groove for arranging the plurality of balls is formed on the support member by press molding.   In a turning table device that supports a table rotated around a vertical axis by an actuator on a support member on a lower side, a shaft portion is provided on the lower side of the table, and at least a sliding surface is provided in a radial direction of the shaft portion. A thrust washer, which is supported by a plain bearing made of resin and has at least a sliding surface made of resin between the support member and the lower surface of the table, is inserted around the shaft portion, and the axial direction of the table Is supported by the thrust washer.   The turning table device according to claim 3, wherein the support member is a thin press-formed product, and an annular groove into which the thrust washer is fitted is formed in the support member by press molding.   5. The swivel table device according to claim 1, wherein the resin forming the sliding surface of the sliding bearing and the resin forming the sliding surface of the ball surface or the thrust washer are heat-resistant resins.   The turning table device according to any one of claims 1 to 5, further comprising means for preventing the shaft portion of the table from being detached from the support member.   The swing according to any one of claims 1 to 6, wherein the actuator is linearly driven in a horizontal direction, and the linear motion of the actuator is converted into a rotational motion of the table by meshing of a rack and a pinion. Table device.   The turning table device according to claim 7, wherein the pinion is formed on an outer periphery of a shaft portion of the table.

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