JP2010112554A - Linear motion bearing with rotary bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a linear motion bearing with a rotary bearing which can be manufactured easily and make the linear movement and/or the rotary movement of the axial body with a high degree of accuracy. <P>SOLUTION: The linear motion bearing with a rotary bearing includes a linear motion bearing (13) which accommodates the axial body (12) in a cylinder (11) non-rotatably and non-slidably and a plurality of rotary bearings (14) installed with at intervals along the longitudinal direction of the cylinder around the cylinder. The diameter of the peripheral face of the above cylinder is constant in the longitudinal direction of the cylinder, and the above rolling bearing comprises a circumferential groove (11a) formed on the outer peripheral face of the cylinder, a plurality of rolling bodies (15) arranged on this circumferential groove, an annular rolling body retainer (16) rotatably retaining the rolling bodies with part of them projecting to the outer peripheral side, an annular body (17) equipped with a peripheral groove (17a) to accommodate the part of the rolling body part projecting from the retainer on an inner circumference face. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a linear motion bearing with a rotary bearing that can be advantageously used as a component of an electronic component mounting apparatus that mounts an electronic component on the surface of a printed wiring board.

  Conventionally, a shaft body having a nozzle with an electronic component adsorbed on the lower end is arranged above the printed wiring board, and the shaft body is rotated and moved in the circumferential direction so that the electronic component is disposed at a predetermined angle. Next, there is known an electronic component mounting apparatus for mounting an electronic component at a predetermined position on the surface of the printed wiring board at a predetermined angle by linearly moving (sliding) the shaft body downward (to the printed wiring board side). It has been.

  In order to realize the linear movement and the rotational movement of the shaft body, a linear motion bearing with a rotary bearing having a combination of a linear motion bearing and a rotary bearing is used.

  In Patent Document 1, a ball having a configuration in which a ball screw nut and a ball spline nut (tubular body) are fitted via a plurality of balls to a ball screw shaft (shaft body) having a ball screw groove and a ball spline groove. A screw device is disclosed.

  A shaft body is accommodated in the cylinder so as to be slidable with respect to the cylinder. The cylindrical body that accommodates the shaft functions as a linear motion bearing. A pair of circumferential grooves are formed around the cylindrical body at intervals in the longitudinal direction of the cylindrical body. Around the cylindrical body, a housing having a pair of circumferential grooves for accommodating the balls on the inner circumferential surface is fitted via a plurality of balls arranged in the circumferential grooves. The cylinder is rotatably supported inside the housing. The pair of circumferential grooves, the plurality of balls arranged in the circumferential grooves, and the housing function as a rotary bearing.

  Patent Document 2 discloses a ball screw device having the same configuration as the above-described ball screw device. The ball spline nut (cylinder) of the ball screw device of Patent Document 2 is formed with a rolling element insertion hole that communicates from the inner peripheral surface to the inner ring groove (circumferential groove) on the outer peripheral surface. Each ball is inserted into the rolling element insertion hole from the inner peripheral surface side of the cylinder, and is disposed in a peripheral groove on the outer peripheral surface of the cylinder through the insertion hole.

Japanese Utility Model Publication No. 4-97150 (FIG. 1) Japanese Utility Model Publication No. 4-110255 (Fig. 1)

  In the devices described in the above documents, the shaft body accommodated in the cylindrical body of the linear motion bearing can be rotationally moved by rotationally moving the linear motion bearing supported by the rotary bearing. However, when the plurality of balls arranged in each circumferential groove of the cylindrical body move (roll) while rotating in the length direction of the circumferential groove along with the rotational movement of the linear motion bearing, Adjacent balls touch. Since each ball rotates in the same direction inside the circumferential groove, the surface of each ball is strongly rubbed while moving in the opposite direction at the contact portion of both balls. For this reason, the wear of the ball due to the contact, and the accuracy of the linear movement and / or rotational movement of the shaft due to the wear of the ball may be problematic.

  An object of the present invention is to provide a linear motion bearing with a rotary bearing that is easy to manufacture and that can linearly move and / or rotate a shaft body with high accuracy.

  The present invention is a linear motion bearing in which a shaft body is slidably accommodated in a non-rotating manner inside a cylindrical body, and is mounted around the cylindrical body at intervals from each other along the length direction of the cylindrical body. A linear motion bearing with a rotary bearing comprising two or more rotary bearings, wherein a diameter of an outer peripheral surface of the cylindrical body is constant in a length direction of the cylindrical body, and each rotary bearing is connected to the outer periphery of the cylindrical body A circumferential groove formed on the surface, a plurality of rolling elements arranged in the circumferential groove, and an annular rolling element holder that holds the rolling elements rotatably in a state in which a part of each rolling element protrudes to the outer circumferential side. The linear motion bearing with a rotary bearing is characterized in that it is composed of an annular body provided on the inner peripheral surface with a circumferential groove that accommodates each rolling element portion protruding from the rolling element cage.

The preferable aspect of the linear motion bearing with a rotary bearing of this invention is as follows.
(1) The annular bodies of the rotary bearings are connected to each other to form an outer cylinder.
(2) The difference between the diameter of the inner peripheral surface of the annular body and the diameter of the outer peripheral surface of the cylindrical body is a length in the range of 1.2 to 1.95 times the diameter of the rolling element.
(3) The annular rolling element cage of each rotary bearing includes a peripheral wall arranged coaxially with the cylindrical body in which a plurality of through holes for holding the respective rolling elements are formed, and the rolling bearing of one rotary bearing is provided. A plurality of slits reaching the end surface of the other rotary bearing from each through hole is formed in the peripheral wall of the moving body cage, and each of the peripheral walls of the rolling body cage of the other rotary bearing is A plurality of slits reaching the end surface of the one rotary bearing from the through hole are formed, and the width of each slit of each rolling element cage is 0.7 to 0.95 times the diameter of the rolling element. The length is within the range.

  In the present specification, the phrase “the diameter of the outer peripheral surface of the cylinder is constant in the length direction of the cylinder” refers to, for example, chamfering the end of the cylinder that is performed to ensure safety. Variations in the diameter of the outer peripheral surface of the cylinder, fluctuations in the diameter of the outer peripheral surface of the cylinder based on fine irregularities that are inevitably generated by machining when manufacturing the cylinder, and normal manufacturing errors of the cylinder (cylinder Of the cylindrical body based on the irregularities formed on the outer peripheral surface of the cylindrical body regardless of the fluctuation of the diameter of the outer peripheral surface of the cylindrical body based on the diameter of the outer peripheral surface of It does not mean that the fluctuation of the diameter of the outer peripheral surface is excluded.

  In the linear motion bearing with a rotary bearing according to the present invention, each rolling element of the rotary bearing is held by the annular rolling element cage, thereby preventing contact between adjacent balls inside each circumferential groove of the cylindrical body. The For this reason, the wear of the ball due to the contact (collision) of the ball and the reduction in the accuracy of the linear movement and / or the rotational movement of the shaft body due to the wear of the ball are suppressed. In the linear motion bearing with a rotary bearing according to the present invention, the diameter of the outer peripheral surface of the cylindrical body is constant in the length direction of the cylindrical body. For this reason, a cylinder can be produced very easily. Then, by forming a circumferential groove on the outer peripheral surface of the cylindrical body and mounting the rotary bearing around the cylindrical body using the circumferential groove, the linear motion bearing with the rotary bearing of the present invention is manufactured very easily. be able to.

It is a partially notched front view which shows the structural example of the linear motion bearing with a rotary bearing of this invention. It is an expanded sectional view of the linear motion bearing 10 with a rotary bearing cut | disconnected along the cutting line II-II line entered in FIG. It is the figure which looked at the annular rolling element holder | retainer 16 shown in FIG. 2 from the near side of the figure. It is sectional drawing of the annular rolling element holder | retainer 16 cut | disconnected along the cutting line IV-IV line entered in FIG. It is a figure which shows the mode of use of the linear motion bearing 10 with a rotary bearing of FIG. It is a partially notched front view which shows another structural example of the linear motion bearing with a rotary bearing of this invention.

  A linear motion bearing with a rotary bearing according to the present invention will be described with reference to the accompanying drawings. FIG. 1 is a partially cutaway front view showing a configuration example of a linear motion bearing with a rotary bearing according to the present invention. FIG. 2 is an enlarged cross-sectional view of the linear motion bearing 10 with a rotary bearing cut along the cutting line II-II entered in FIG. FIG. 3 is a view of the annular rolling element holder 16 shown in FIG. 2 as viewed from the front side of the figure. 4 is a cross-sectional view of the annular rolling element holder 16 cut along the cutting line IV-IV entered in FIG.

  A linear motion bearing 10 with a rotary bearing shown in FIG. 1 to FIG. 4 includes a linear motion bearing 13 in which a shaft body 12 is slidably accommodated in a cylindrical body 11 in a non-rotatable manner, and a cylinder around the cylindrical body 11. It consists of two rotary bearings 14 mounted at intervals along the length direction of the body 11. In the linear motion bearing 10 with a rotary bearing, the diameter of the outer peripheral surface of the cylindrical body 11 is constant in the length direction of the cylindrical body 11, and each rotary bearing 14 is formed on the outer peripheral surface of the cylindrical body 11. A circumferential groove 11a, a plurality of rolling elements 15 arranged in the circumferential groove 11a, and an annular rolling element holder 16 that rotatably holds a part of each rolling element 15 protruding to the outer peripheral side. The annular member 17 is provided with a circumferential groove 17a that houses each rolling element portion protruding from the cage 16 on the inner peripheral surface.

  In the linear motion bearing 10 with the rotary bearing of the present invention, the diameter of the outer peripheral surface of the cylindrical body 11 of the linear motion bearing 13 is constant in the length direction of the cylindrical body 11 as described above. For this reason, the cylinder 11 can be produced very easily. Then, a circumferential groove 11a is formed on the outer peripheral surface of the cylindrical body 11, and the rotary bearing 14 is mounted around the cylindrical body 11 using the circumferential groove 11a. Can be manufactured.

  A plurality of grooves 21 each extending in the length direction of the cylindrical body 11 are formed on the inner peripheral surface of the cylindrical body 11. A plurality of grooves 22 extending in the length direction of the shaft body 12 are formed on the outer peripheral surface of the shaft body 12 at positions facing the grooves 21 of the cylindrical body 11. A plurality of spheres 25 are arranged along the length direction of the groove between the cylindrical groove 21 and the shaft groove 22 facing the groove 21.

  The cylindrical body 11, the shaft body 12, and the spherical body 25 are formed of, for example, a metal material typified by steel or a copper alloy.

  A cylindrical rolling element holder 26 is disposed between the cylindrical body 11 and the shaft body 12 in order to prevent contact (collision) between the spherical bodies 25 adjacent to each other. The cylindrical rolling element holder 26 includes a plurality of through holes 26a, and holds the spherical body 25 in a rotatable state inside each through hole 26a.

  The cylindrical rolling element holder 26 is made of, for example, a metal material or a resin material. As the metal material, it is preferable to use a metal material, for example, brass or stainless steel, which can easily form the through holes 26a by machining. As the resin material, it is preferable to use a resin material having high mechanical strength, for example, a polyacetal resin, a polyphenylene sulfide (PPS) resin, or a polyether ether ketone (PEEK) resin.

  Moreover, it was formed in the inner peripheral surface of each edge part of the cylinder 11 so that the cylindrical rolling element holder | retainer 26 may not come out of the cylinder 11 with the spherical body 25, when the shaft body 12 moves linearly. A snap ring (retaining ring) 27 is fitted in the circumferential groove 11b.

  As described above, since the spherical body 25 is disposed between the groove 21 of the cylindrical body 11 and the groove 22 of the shaft body 12, the shaft body 12 rotates in the circumferential direction inside the cylindrical body 11. I can't. On the other hand, when a force is applied in the length direction of the shaft body 12, each spherical body 25 rolls along the length direction of the groove between the groove 21 of the cylindrical body 11 and the groove 22 of the shaft body 12. Therefore, the shaft body 12 can slide (linearly move) in the length direction inside the cylinder body 11.

  As the linear motion bearing, a publicly known linear motion bearing (generally called a linear motion guide device) in which a shaft body is slidably accommodated in a non-rotating manner can be used.

  As an example of such a linear bearing, a groove is formed along the length direction on one of the opposing surfaces of the cylindrical body and the shaft body, and a protrusion that fits into the groove is formed on the other surface. By doing so, there is a linear motion bearing in which the cylindrical body and the shaft body are engaged, thereby making the shaft body non-rotating in the circumferential direction and slidable in the length direction.

  As another example, a groove is formed along the length direction on each of the opposing surfaces of the cylinder and the shaft, and a plurality of rolling elements are disposed between the groove of the cylinder and the groove of the shaft. The cylindrical body and the shaft body are engaged with each other through a rolling element, thereby making the shaft body non-rotating in the circumferential direction and slidable in the length direction (typical example, in FIG. 1). The linear bearing 13) shown is mentioned.

  As yet another example, a groove is formed in the outer circumferential surface of the shaft body along the length direction, and a plurality of rolling elements are arranged in the groove so that the shaft body can slide in the length direction. On the other hand, the cylindrical body and the shaft body are fixed by fixing a cylindrical rolling body holder having a track for circulating the plurality of rolling bodies between the cylindrical body and the shaft body. Examples thereof include a cylindrical rolling element cage and a linear motion bearing that is engaged via the rolling element, thereby making the shaft body non-rotating in the circumferential direction.

  Since the structure of the linear bearing is well known, further explanation is omitted.

  As described above, each rotary bearing 14 of the linear motion bearing 10 with a rotary bearing according to the present invention includes a circumferential groove 11a formed on the outer peripheral surface of the cylindrical body 11, and a plurality of rolling elements (spheres) arranged in the circumferential groove 11a. 15), an annular rolling element holder 16 that rotatably holds a part of each rolling element 15 protruding to the outer peripheral side, and each rolling element portion protruding from the holder 16. It is comprised from the annular body 17 provided with the circumferential groove 17a in an internal peripheral surface.

  For example, when the shaft body 12 of the linear motion bearing 13 is rotated in the circumferential direction, the cylindrical body 11 that accommodates the shaft body 12 in a non-rotating state also rotates in the circumferential direction. Along with the rotation of the cylinder 11, the plurality of rolling elements 15 of each rotary bearing 14 roll along the circumferential groove 11 a of the cylinder 11. For this reason, the linear motion bearing 13 can rotate smoothly while being supported by the two rotary bearings 14. As the rolling elements of the rotary bearing 14, rollers (rollers) can be used.

  An annular rolling element cage 16 is disposed between the annular body 17 and the cylinder 11 of each rotary bearing 14. As shown in FIGS. 3 and 4, the annular rolling element holder 16 includes a plurality of through holes 16 a, and holds the rolling elements 15 in a rotatable state inside each through hole 16 a. For this reason, the contact of the adjacent rolling elements 15 is prevented. Therefore, the wear of the rolling element 15 is suppressed, and the cylindrical body 11 of the linear motion bearing 13 is tightly supported by the annular body 17 via the plurality of rolling elements 15, so that it is accommodated in the cylindrical body 11 of the linear motion bearing 13. Further, the rotational movement of the shaft body 12 with high accuracy is realized. Further, since the occurrence of relative fine movement in the axial direction between the annular body 17 and the cylindrical body 11 is suppressed, the linear movement with high accuracy of the shaft body 12 accommodated in the cylindrical body 11 of the linear motion bearing 13 is achieved. Is realized.

As shown in FIGS. 1 to 4, the annular rolling element holder 16 includes a peripheral wall 16 b disposed coaxially with the cylindrical body 11 in which a plurality of through holes 16 a for holding the rolling elements 15 are formed. Then, the peripheral wall 16b of the rolling element cage 16 of the rotary bearing 14 of one side (upper side in FIG. 1) extends from each through hole 16a to the end surface of the rotary bearing 14 side of the other side (lower side in FIG. 1). A plurality of reaching slits 16c are formed, and the peripheral wall 16b of the rolling element holder 16 of the other (lower) rotary bearing 14 is connected to the one (upper) rotary bearing 14 from each through hole 16a. A plurality of slits 16c reaching the end face on the side are formed, and the width (W ₁ ) of each slit 16c of each rolling element holder 16 is 0.7 of the diameter (FIG. 2: D ₃ ) of the rolling element 15. It is preferable that the length is in a range of ˜0.95 times. In addition, when using a roller (roller) as a rolling element, the above-mentioned "diameter of a rolling element" is a diameter in a cross section perpendicular to the central axis of the roller (however, when the diameter of the roller varies in the axial direction) Means the largest diameter).

  The annular rolling element retainer 16 has a plurality of rolling elements 15 disposed between the circumferential groove 17 a of the annular body 17 and the circumferential groove 11 a of the cylindrical body 11, and then the annular body from one end side of the annular body 17. 17 and the cylinder 11 are inserted. When the annular rolling element holder 16 is inserted between the annular body 17 and the cylindrical body 11, each rolling element 15 is accommodated in the through hole 16a.

As shown in FIGS. 3 and 4, the width (W ₂ ) of the end of each slit 16 c of the annular rolling element holder 16 opposite to the through hole 16 a side is larger than the width (W ₁ ). It is preferably enlarged. Thereby, since the rolling element 15 easily enters the slit 16c from the end portion, it is further easy to accommodate the rolling element 15 in the through hole 16a of the annular rolling element holder 16. The width (W ₂ ) of the end of the slit 16c opposite to the through hole 16a is 1.05 to 2 times (particularly 1.05 to 1.5 times) the width (W ₁ ). It is preferable to be within the range.

  An end of the peripheral wall 16b of the annular rolling element retainer 16 opposite to the side where the slit 16c is formed is provided with an annular protrusion 16d extending from the periphery of the end toward the inner periphery. preferable. Thereby, the mechanical strength of the annular rolling element holder 16 is increased.

  The annular body 17 and the rolling element 15 of the rotary bearing 14 are made of, for example, a metal material typified by steel or a copper alloy, as in the case of the cylindrical body 11 and the spherical body 25 of the linear motion bearing 13. The annular rolling element holder 16 is formed of a metal material or a resin material as in the case of the cylindrical rolling element holder 26.

The difference between the diameter of the inner peripheral surface of the annular body 17 (FIG. 2: D ₁ ) and the diameter of the outer peripheral surface of the cylindrical body 11 (FIG. 2: D ₂ ) is the diameter of the rolling element 15 (FIG. 2: D ₃ ). The length is preferably in the range of 1.2 to 1.95 times. Thus, a large gap is formed between the annular body 17 and the cylinder 11 by moving the annular body 17 in the radial direction of the cylinder 11. From the gap, the plurality of rolling elements 15 can be easily inserted between the annular body 17 and the cylindrical body 11.

  If the difference between the diameter of the inner peripheral surface of the annular body 17 and the diameter of the outer peripheral surface of the cylindrical body 11 is 1.2 or more times the diameter of the rolling element 15, the gap becomes larger, so that the rolling element 15 Easy to insert. On the other hand, when the difference between the diameter of the inner peripheral surface of the annular body 17 and the diameter of the outer peripheral surface of the cylindrical body 11 is 1.95 times or less the diameter of the rolling element 15, each of the annular body 17 and the cylindrical body 11 Since the depth of the circumferential groove can be sufficiently increased, the rolling element 15 is prevented from falling off between the circumferential grooves.

  The difference between the diameter of the inner peripheral surface of the annular body 17 and the diameter of the outer peripheral surface of the cylindrical body 11 is preferably a length in the range of 1.3 to 1.8 times the diameter of the rolling element 15. More preferably within the range of 3 to 1.7 times, and particularly preferably within the range of 1.3 to 1.6 times.

  In the linear motion bearing 10 with a rotary bearing of the present invention, the circumferential groove 11 a formed on the outer peripheral surface of the cylindrical body 11 of the linear motion bearing 13 is used as the raceway of the plurality of rolling elements 15 of the rotary bearing 14. Such a circumferential groove 11a is formed by, for example, machining using a lathe or a cylindrical grinding machine, and the central axis of the circumferential groove 11a (that is, the central axis of the rotary bearing 14) and the central axis of the cylindrical body 11 (that is, linear motion). It is easy to form in a state where the center axis of the bearing 13 is exactly matched. Then, by arranging a plurality of rolling elements 15 in the circumferential groove 11 a on the outer peripheral surface of the cylindrical body 11 and assembling the rotary bearing 14, the central axis of the rotary bearing 14 is easily aligned with the central axis of the linear motion bearing 13. be able to. For this reason, the linear motion bearing 10 with a rotary bearing of the present invention can stably realize linear movement and / or rotational movement of the shaft body 12 with high accuracy without taking assembly accuracy into consideration.

  Moreover, since the linear motion bearing 10 with a rotation bearing uses the circumferential groove 11a formed in the outer peripheral surface of the cylindrical body 11 of the linear motion bearing 13 as a track | orbit of the some rolling element 15 of the rotation bearing 14, the diameter direction It is easy to reduce the size.

  The number of rotary bearings to be mounted around the cylindrical body 11 of the linear motion bearing 13 is not particularly limited as long as it is two or more, but it is within a range of two to four because it is easy to assemble. Is preferable, and two is particularly preferable.

  FIG. 5 is a diagram showing a mode of use of the linear motion bearing 10 with a rotary bearing in FIG. 1. FIG. 5 shows a main part of an apparatus for mounting electronic components on the surface of a printed wiring board.

  As shown in FIG. 5, the linear motion bearing 10 with a rotary bearing is used, for example, in a state of being housed and fixed in a cylindrical container 52 fixed to a support column 51. This cylindrical container 52 is comprised from the main body 52a and the lid | cover 52b which can be screwed to the upper part of the main body 52a. A cylindrical spacer 53 that prevents the annular body 17 of each rotary bearing 14 from swinging is fitted inside the main body 52a.

  A connecting member 55 for connecting the exhaust pipe 54 to the through hole (FIG. 1: 12a) of the shaft body 12 is fixed to the upper end portion of the shaft body 12 of the linear motion bearing 10 with a rotary bearing. By exhausting the inside of the through hole of the shaft body 12 with a pump or the like through the exhaust pipe 54 and the gas passage 55 a of the connection member 55, the electronic component can be adsorbed to the lower end portion of the shaft body 12. A nozzle for attracting an electronic component can be attached to the lower end portion of the shaft body 12. When an exhaust pipe is connected to the nozzle and the electronic component can be adsorbed by the nozzle alone, it is not necessary to provide a through hole (FIG. 1: 12a) in the shaft body 12.

  A rotation driving device 56 a is connected to the upper end portion of the shaft body 12 via the connection member 55. Then, by operating the rotation drive device 56a and rotating the shaft body 12 (that is, the entire linear motion bearing 13), the electronic component attracted to the lower end portion of the shaft body 12 can be rotated at a predetermined angle.

  The rotation drive device 56 a is connected to a rotation drive device 56 b installed on the support column 51 via a feed screw 57. The feed screw 57 includes a screw shaft 57a and a nut 57b. Then, the rotation drive device 56b is operated, and the nut 57b of the feed screw 57 is moved in the vertical direction together with the rotation drive device 56a fixed to the nut 57b and the shaft body 12, so that the electrons adsorbed on the lower end portion of the shaft body 12 are absorbed. Parts can be raised and lowered.

  Accordingly, an electronic component is attracted to the lower end portion of the shaft body 12 of the linear motion bearing 10 with a rotary bearing, and, for example, the shaft body 12 is rotated so that the electronic component is arranged at a predetermined angle, and then lowered. The electronic component can be mounted on the surface of the printed wiring board.

  A cylindrical connecting part is attached to the upper end portion of the cylindrical body 11 of the linear motion bearing 13, and the cylindrical connecting part is rotated together with the shaft body 12 by rotating the cylindrical connecting part. It can also be rotated. That is, a rotary drive device that rotates the shaft body 12 is connected to the cylinder body 11 through the cylindrical connecting part, and a feed screw and a rotary drive device (or a linear drive device) that linearly moves the shaft body 12 are connected to the shaft body 12. They can also be connected independently.

  FIG. 6 is a partially cutaway front view showing another configuration example of the linear motion bearing with a rotary bearing of the present invention.

  In the configuration of the linear motion bearing 60 with a rotary bearing in FIG. 6, the annular bodies of the rotary bearings 14 mounted around the cylindrical body 11 of the linear motion bearing 13 are connected to each other to form an outer cylinder 67. Except for this, it is the same as the linear motion bearing 10 of FIG.

  Since the outer cylinder 67 is less likely to swing in the linear motion bearing 60 with a rotary bearing, the shaft body 12 can be linearly moved and / or rotated with higher accuracy.

DESCRIPTION OF SYMBOLS 10 Linear motion bearing with rotary bearing 11 Cylindrical body 11a, 11b Circumferential groove 12 Shaft body 12a Through-hole 13 Linear motion bearing 14 Rotary bearing 15 Rolling body 16 Annular rolling element holder 16a Through hole 16b Peripheral wall 16c Slit 16d Annular protrusion 17 Annular body 17a Circumferential groove 21 Groove of cylindrical body 22 Groove of shaft body 12 25 Sphere 26 Cylindrical rolling element cage 26a Through hole 27 Snap ring 51 Post 52 Cylindrical container 52a Main body 52b Lid 53 Cylindrical spacer 54 Exhaust Pipe 55 Connecting member 55a Gas passage 56a, 56b Rotation drive device 57 Feed screw 57a Screw shaft 57b Nut 60 Linear motion bearing with rotary bearing 67 Outer cylinder D ₁ Diameter of inner peripheral surface of annular body D ₂ Outer surface of cylindrical body 11 Diameter D ₃ diameter of rolling element 15 W ₁ slit 16c width W ₂ slit 16c end width opposite to through hole 16a side

Claims (4)

A linear motion bearing in which a shaft body is slidably accommodated in a non-rotating manner inside a cylindrical body, and two or more mounted around the cylindrical body at intervals from each other along the length direction of the cylindrical body A linear motion bearing with a rotary bearing comprising a rotary bearing,
The diameter of the outer peripheral surface of the cylindrical body is constant in the length direction of the cylindrical body, and the rotary bearings are arranged in a circumferential groove formed in the outer peripheral surface of the cylindrical body, and the circumferential groove. Accommodates a plurality of rolling elements, an annular rolling element holder rotatably holding a part of each rolling element protruding to the outer peripheral side, and each rolling element portion protruding from the rolling element holder A linear motion bearing with a rotary bearing, comprising: an annular body having a circumferential groove on an inner peripheral surface thereof.   The linear motion bearing with a rotary bearing according to claim 1, wherein the annular bodies of the rotary bearings are connected to each other to form an outer cylinder.   The difference between the diameter of the inner peripheral surface of the annular body and the diameter of the outer peripheral surface of the cylindrical body lies in a length within a range of 1.2 to 1.95 times the diameter of the rolling element. A linear motion bearing with a rotary bearing according to any one of the items.   An annular rolling element cage of each rotary bearing includes a peripheral wall arranged coaxially with the cylindrical body in which a plurality of through holes for holding the rolling elements are formed, and the rolling element cage of one rotary bearing A plurality of slits that reach the end surface of the other rotary bearing from the respective through holes are formed in the peripheral wall of the other rotary bearing, and the peripheral wall of the rolling element cage of the other rotary bearing is formed from the respective through holes. A plurality of slits reaching the end surface on the one rotary bearing side are formed, and the width of each slit of each rolling element holder is in the range of 0.7 to 0.95 times the diameter of the rolling element. The linear motion bearing with a rotary bearing according to any one of claims 1 to 3, wherein the linear motion bearing is in length.

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