JP5410948B2 - Linear motion guide device - Google Patents

Description

  The present invention relates to a linear motion guide device that can be advantageously used when an electronic component is moved to a predetermined position on the surface of a printed wiring board.

  Conventionally, when an electronic component is mounted on the surface of a printed wiring board, a shaft body having an electronic component suction nozzle at the lower end is moved (lifted) in the length direction, and the electronic component sucked by the nozzle is moved to the printed wiring board. There is used an electronic component mounting apparatus which moves to a predetermined position on the surface of the electronic component and mounts it. In such an electronic component mounting apparatus, a linear motion guide apparatus having a configuration in which the shaft body is accommodated in an outer cylinder so as to be slidable (movable in the length direction) without rotation is used.

  In order to move the shaft body of the linear motion guide device in the length direction, for example, a linear motion drive device having a configuration in which a feed screw is connected to the rotational shaft of the rotational drive device is used. The feed screw is composed of a screw shaft connected to the rotary shaft and a nut fitted around the screw shaft. And if the said rotational drive apparatus is operated and the rotating shaft is rotated with a screw shaft, the said nut will move to the length direction of a screw shaft. Therefore, when the shaft body of the linear motion bearing is connected to the nut in a state of being arranged in parallel with the screw shaft of the feed screw, the shaft body of the linear motion guide device is lengthened together with the nut by the operation of the rotary drive device. It becomes possible to move in the direction.

  Further, for example, in order to arrange electronic components on the surface of the printed wiring board at a predetermined angle, it is also possible to use a linear motion guide device with a rotary bearing in which the periphery of the outer cylinder of the linear motion guide device is supported by a rotary bearing. Are known.

  For example, Patent Document 1 discloses a linear motion bearing in which a shaft body (spline shaft) is accommodated in an outer cylinder (spline nut) so as to be slidable (movable in the length direction) without rotation. There is disclosed a linear motion guide device with a rotary bearing comprising a cylindrical body fixed around the cylindrical body and a rotary bearing (angular ball bearing) disposed around the cylindrical body.

  A rotor having a suction nozzle is connected to the lower end of the shaft body of the linear motion guide device with a rotary bearing of the same document, and a rotation driving device (motor) is connected to the upper end. By driving the rotary motor, the shaft rotates with the suction nozzle. On the other hand, a shaft motor for linear motion drive is connected to the cylinder of the linear motion drive device via the rotary bearing. Then, by driving the shaft motor, the cylinder moves up and down together with the suction nozzle.

Japanese Patent Laid-Open No. 2007-305887 (FIG. 3)

  In recent years, electronic components have been extremely miniaturized. For example, a minute electronic component having a side of 1 mm or less (eg, length: 0.4 mm, width 0.2 mm) is accurately moved to a very fine area on the surface of a printed wiring board. There is a need to do that.

  As described above, in the conventional linear motion guide device, when the shaft body is moved in the length direction using the linear motion drive device including the feed screw, the shaft body of the linear motion guide device and the screw of the feed screw are used. If the shaft is not arranged exactly in parallel, a driving force in a direction inclined with respect to the length direction is applied to the shaft body via the nut of the feed screw, so that the drive necessary for the movement of the shaft body is applied. The power fluctuates. For this reason, it becomes difficult to move the shaft body to the predetermined position in the length direction with high accuracy. Therefore, when the conventional linear motion guide device is used, it is necessary to precisely adjust the positional relationship between the shaft body and the screw shaft of the feed screw so that they are arranged in parallel to each other. Moreover, in order to shorten the mounting time of an electronic component, the electronic component mounting apparatus may be provided with a plurality of shaft bodies including the suction nozzle. In such a case, it is not easy to precisely adjust the positional relationship between each shaft body and the screw shaft (shaft body drive device) so that all the shaft bodies move with high accuracy in the length direction. .

  On the other hand, when the shaft body is rotationally driven as in the linear motion guide device with a rotary bearing of Patent Document 1, the center axis of the shaft body of the linear motion guide device and the rotational shaft of the rotational drive device are accurate. If they are not connected so as to coincide with each other, the shaft body of the linear motion guide device rotates in an eccentric state, so that it is difficult to precisely arrange the electronic components at a predetermined angle.

  An object of the present invention is to provide a highly versatile linear motion guide device that can move a shaft body in a lengthwise and highly accurate manner and that can easily add a function of rotating the shaft body. It is in.

  The present invention is a feed screw composed of a screw shaft and a nut fitted around the screw shaft, formed as an extension of each end of the screw shaft, and formed on the outer peripheral surface along the length direction. A linear motion bearing comprising a support shaft having a plurality of grooves, and a linear bearing having an outer cylinder that slidably accommodates and supports each support shaft in a non-rotatable manner via a plurality of rolling elements that engage with each groove. It is in the motion guide device.

Hereinafter, such a device having a plurality of grooves on the support shafts on both sides of the feed screw is referred to as a double-side groove type linear motion guide device. Preferred embodiments of the linear motion guide device (both side groove type) of the present invention are as follows.
(1) Two or more rotary bearings are mounted around the nut of the feed screw.
(2) Each rotary bearing mounted around the nut includes a circumferential groove formed on the outer circumferential surface of the nut, a plurality of rolling elements arranged in the circumferential groove, and the rolling elements on the inner circumferential side and the outer circumferential side. An annular cage that is rotatably held in a state of partially protruding to the side, and an annular body that includes a circumferential groove on the inner circumferential surface that accommodates each rolling element portion that is projected to the outer circumferential side of the annular cage; It is composed of More preferably, the diameter of the outer peripheral surface of the nut is constant in the length direction of the nut.
(3) The difference between the diameter of the inner peripheral surface of the annular body of each rotary bearing mounted around the nut and the diameter of the outer peripheral surface of the nut is in the range of 1.2 to 1.95 times the diameter of the rolling element. Is in the length of.
(4) An annular cage of each rotary bearing mounted around the nut includes a peripheral wall arranged coaxially with the nut in which a plurality of through holes for holding the rolling elements are formed, The peripheral wall of the annular cage of the rotary bearing is formed with a plurality of slits that reach the end surface of the other rotary bearing from the respective through holes, and the peripheral wall of the annular cage of the other rotary bearing, A plurality of slits reaching the end surface of the one rotary bearing from each through hole are formed, and the width of each slit of each annular cage is 0.7 to 0.95 times the diameter of the rolling element. The length is within the range.
(5) A through hole is formed on the central axis of the screw shaft and each support shaft. More preferably, it is for an electronic component mounting apparatus.

  The present invention is also a linear motion guide device with a rotary bearing in which two or more rotary bearings are mounted around an outer cylinder of each linear motion bearing of the linear motion guide device.

Hereinafter, this is referred to as a linear motion guide device with a rotary bearing of a double-sided groove type. The preferable aspect of this linear motion guide apparatus with a rotary bearing (double-sided groove type) is as follows.
(1) Each rotary bearing mounted around the outer cylinder has a circumferential groove formed on the outer circumferential surface of the outer cylinder, a plurality of rolling elements arranged in the circumferential groove, and each rolling element on the inner circumferential side. And an annular retainer that is rotatably held in a state of being partially protruded to the outer peripheral side, and an annular member that has an inner peripheral surface with a circumferential groove that accommodates each rolling element portion protruded to the outer peripheral side of the annular retainer It is composed of the body. More preferably, the diameter of the outer peripheral surface of the outer cylinder is constant in the length direction of the outer cylinder.
(2) The difference between the diameter of the inner peripheral surface of the annular body of each rotary bearing mounted around the outer cylinder and the diameter of the outer peripheral surface of the outer cylinder is 1.2 to 1.95 times the diameter of the rolling element. The length is within the range.
(3) An annular cage of each rotary bearing mounted around the outer cylinder includes a peripheral wall disposed coaxially with the outer cylinder in which a plurality of through holes for holding the rolling elements are formed. The peripheral wall of the annular cage of one rotary bearing is formed with a plurality of slits that reach the end surface of the other rotary bearing from the respective through holes, and the peripheral wall of the annular cage of the other rotary bearing Are formed with a plurality of slits that reach the end face on the one rotary bearing side from each through hole, and the width of each slit of each annular cage is 0.7 to 0. 0 of the diameter of the rolling element. The length is in the range of 95 times.

  The present invention also provides a feed screw comprising a screw shaft and a nut fitted around the screw shaft, a support shaft having a circular cross section formed as an extension of one end of the screw shaft, and the support shaft as an outer peripheral surface thereof. A linear motion bearing having an outer cylinder slidably received and supported via a plurality of rolling elements disposed on the outer peripheral surface, formed as an extension of the other end of the screw shaft; A support shaft having a plurality of grooves formed along the length direction, and an outer cylinder that slidably accommodates and supports the support shaft in a non-rotatable manner via a plurality of rolling elements that engage with the grooves. There is also a linear motion guide device comprising a linear motion bearing having

  Hereinafter, the one having a plurality of grooves on the support shaft on one side of the feed screw is referred to as a one-side groove type linear motion guide device. A preferred embodiment of the linear motion guide device (one-side groove type) of the present invention is the same as the linear motion guide device (both-side groove type).

  The present invention is also a linear motion guide device with a rotary bearing in which two or more rotary bearings are mounted around the outer cylinder of each linear motion bearing of the linear motion guide device (one-side groove type).

  Hereinafter, this is referred to as a one-side groove type linear motion guide device with a rotary bearing. A preferred mode of the linear motion guide device with a rotary bearing (one-side groove type) is the same as that of the linear motion guide device with a rotary bearing (double-side groove type).

  In the present specification, “the diameter of the outer peripheral surface of the nut is constant in the length direction of the nut” means, for example, that the nut is chamfered by chamfering the end of the nut to ensure safety. Fluctuations in the diameter of the outer peripheral surface, fluctuations in the diameter of the outer peripheral surface of the nut based on fine irregularities inevitably caused by machining when manufacturing the nut, normal manufacturing errors of the nut (± 1 of the diameter of the outer peripheral surface of the nut) % Variation in the diameter of the outer peripheral surface of the nut, or the variation in the diameter of the outer peripheral surface of the nut based on the irregularities formed on the outer peripheral surface of the nut regardless of the function of the linear motion guide device. It is not a thing.

  Similarly, “the diameter of the outer peripheral surface of the outer cylinder is constant in the length direction of the outer cylinder” means, for example, the outer periphery of the outer cylinder caused by chamfering the end of the outer cylinder performed for ensuring safety. Fluctuation of surface diameter, fluctuation of outer peripheral surface diameter due to fine irregularities that are inevitably caused by machining when manufacturing the outer cylinder, normal manufacturing error of outer cylinder (diameter of outer peripheral surface of the outer cylinder) The diameter of the outer cylinder's outer peripheral surface based on irregularities formed on the outer peripheral surface of the outer cylinder regardless of the fluctuations in the diameter of the outer cylinder's outer diameter based on It does not mean to eliminate fluctuations.

  The linear motion guide device according to the present invention can easily connect the support shaft (shaft body) to the drive device when the device is incorporated in a mechanical device such as an electronic component mounting device. It can be moved with high accuracy in a stable direction. The linear motion guide device of the present invention can add a function of rotating the support shaft very easily by mounting two (or more) rotary bearings around the outer cylinder of the linear motion bearing. Because it can, it is excellent in versatility.

It is a partially notched front view which shows the structural example of the linear motion guide apparatus of this invention. It is an enlarged view of the site | part of the vicinity of the linear motion bearing 23a shown in FIG. It is sectional drawing of the linear motion bearing 23a cut | disconnected along the cutting line II entered in FIG. It is a figure which shows the aspect of use of the linear guide apparatus 10 of FIG. It is a partially notched front view which shows the structural example of the linear motion guide apparatus with a rotating bearing of this invention, and the mode of its use. It is a partially notched front view which shows another structural example of the linear guide apparatus with a rotary bearing of this invention, and the mode of its use. It is an enlarged view of the site | part of the vicinity of the linear motion bearing 73a shown in FIG. FIG. 8 is a plan view of an annular cage 86 of the lower rotary bearing 83 shown in FIG. 7. It is sectional drawing of the annular holder | retainer 86 cut | disconnected along the cutting line II-II line entered in FIG. It is a partially notched front view which shows another structural example of a linear motion bearing. It is sectional drawing of the linear motion bearing 103 and the support shaft 21 which were cut | disconnected along the cutting line III-III line entered in FIG. It is a partially notched front view which shows another structural example of the linear motion guide apparatus of this invention. It is an enlarged view of the site | part of the vicinity of the linear motion bearing 123 shown in FIG. It is sectional drawing of the linear bearing 123 and the support shaft 121 which were cut | disconnected along the cutting line IV-IV line entered in FIG.

  First, a linear motion guide device (both-side groove type) of 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 the linear motion guide device of the present invention. FIG. 2 is an enlarged view of a portion in the vicinity of the linear motion bearing 23a shown in FIG. However, the rolling elements arranged at positions near the upper and lower ends of the rolling element circulation path 26 are not shown. 3 is a cross-sectional view of the linear motion bearing 23a and the support shaft 21 cut along the cutting line I-I entered in FIG.

  A linear guide device (both-side groove type) 10 shown in FIGS. 1 to 3 is an extension of each of a feed screw 13 including a screw shaft 11 and a nut 12 fitted around the screw shaft 11 and both ends of the screw shaft 11. The formed support shafts 21, 21 having a plurality of grooves 21a formed along the length direction on the outer peripheral surface, and a plurality of rolling elements 25 that engage each support shaft 21 with each groove 21a. It comprises linear motion bearings 23a and 23b having an outer cylinder 22 that is slidably housed and supported in a non-rotatable manner.

  As the feed screw 13, a known one, for example, a ball screw having a configuration in which the nut 12 is fitted around the screw shaft 11 through a plurality of rolling elements housed in the screw groove of the screw shaft 11 is used. it can.

  Support shafts 21, 21 having a plurality of grooves 21 a are formed as extensions of both ends of the screw shaft 11. The support shafts 21 and 21 and the screw shaft 11 are made of, for example, a metal material typified by steel.

  In the case of the linear motion guide device 10, the linear motion bearings 23a and 23b have the same configuration. Below, the structure of the linear motion bearing used for this invention is demonstrated by making the linear motion bearing 23a into a representative example.

  The support shaft 21 is accommodated and supported in a non-rotatable manner inside the outer cylinder 22 of the linear motion bearing 23a via a plurality of rolling elements 25 engaged with the grooves 21a. A spherical body is used as the rolling element 25. Rollers may be used instead of the spheres. The outer cylinder 22 and each rolling element 25 are formed from, for example, a metal material typified by steel.

  Inside the outer cylinder 22, a plurality of rolling elements 25 interposed between the outer cylinder 22 and the support shaft 21 are rotatably held in a state where each rolling element 25 protrudes toward the inner peripheral side, and A cylindrical cage 27 having a rolling element circulation path 26 for circulating a rolling element group including a plurality of rolling elements 25 between the outer cylinder 22 and the support shaft 21 is fixed.

  The cylindrical retainer 27 is provided with, for example, four rolling element circulation paths 26. Each of the rolling element circulation paths 26 is formed on the outer peripheral surface of the cylindrical cage 27, and includes a rolling element protrusion groove 26 a having an elongated opening 24 that protrudes a part of the rolling element 25 toward the inner peripheral side, and a rolling element. The connecting groove 26b connects both ends of the protruding groove 26a.

  The cylindrical cage 27 is formed from, for example, a metal material or a resin material. As the metal material, it is preferable to use a metal material that can be easily machined, for example, brass or stainless steel. 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.

  In the linear motion bearing 23 a, each rolling element 25 protruding from the opening 24 of the cylindrical cage 27 fixed to the inner side of the outer cylinder 22 is engaged with each groove 21 a of the support shaft 21. Therefore, the support shaft 21 is accommodated and supported in the outer cylinder 22 of the linear motion bearing 23a in a non-rotating state in the circumferential direction and slidable (smoothly movable) in the length direction. .

  As the linear motion bearing used in the present invention, a known linear motion bearing having an outer cylinder that slidably accommodates and supports the support shaft in a non-rotatable manner by engagement between the groove of the support shaft and the rolling element is used. be able to.

  Retaining rings (snap rings) 28, 28 fitted in annular grooves 22 a formed on the inner peripheral surface of the outer cylinder 22 are provided on both outer sides in the axial direction of the cylindrical cage 27. The retaining ring 28 is made of, for example, a material exhibiting elasticity such as a metal material or a resin material, and has a C-shape with a part of the circumferential direction cut away. The retaining ring 28 is inserted into the inside from the opening at the end of the outer cylinder 22 in a state where the outer peripheral edge is elastically deformed so as to reduce the outer diameter by applying a force. When the retaining ring 28 reaches the annular groove 22a of the outer cylinder 22, the retaining ring 28 returns to its original shape and is accommodated in the annular groove 22a. The retaining rings 28 and 28 prevent the cylindrical retainer 27 from moving in the axial direction. For example, the cylindrical retainer can be bonded to the inner peripheral surface of the outer cylinder to prevent movement in the axial direction.

  Next, the operation of the linear motion guide device 10 will be described with reference to the attached FIG.

  The linear motion guide device 10 of the present invention is used, for example, in an electronic component mounting device. A through hole 19 is formed on the central axis of the screw shaft 11 and the support shafts 21 and 21 in order to suck the electronic component at the lower end portion of the support shaft 21. On the other hand, a connecting member 52 for connecting the exhaust pipe 51 to the through hole 19 is fixed to the upper end portion of the support shaft 21 supported by the linear motion bearing 23b. By exhausting the inside of the through hole 19 with a pump or the like through the exhaust pipe 51 and the gas passage 52a of the connection member 52, the electronic component is adsorbed to the lower end portion of the support shaft 21 supported by the linear motion bearing 23a. Can do. In addition, if the through hole 19 is provided in the support shaft 21, for example, thermal expansion of the support shaft due to heat generation during operation of the drive device of the support shaft can be suppressed. Accuracy (straightness) is improved.

  A nozzle suitable for suction of electronic components can be attached to the lower end portion of the support shaft 21 supported by the linear motion bearing 23a. When the exhaust pipe is connected to the nozzle and the electronic component can be adsorbed by the nozzle alone, it is not necessary to provide the through hole 19 in the screw shaft 11 and the support shafts 21 and 21.

  The feed screw 13 is housed and fixed in a cylindrical container 53 via two rotary bearings 43 and 43 mounted around the nut 12. The container 53 is fixed to a support column 59 provided in the electronic component mounting apparatus.

  As each rotary bearing 43, the inner peripheral side annular body 44 in which the peripheral groove 44a was formed in the outer peripheral surface, the some rolling element 45 arrange | positioned at the peripheral groove 44a, and each rolling element 45 are set to the inner peripheral side and outer peripheral side. An annular retainer 46 that is rotatably held in a partially projecting state, and an outer periphery provided with a circumferential groove 47a for housing each rolling element portion projecting toward the outer periphery of the annular retainer 46 A known rotary bearing provided with a side annular body 47 is used. It is preferable that the two (or more) rotary bearings 43 and 43 are mounted around the nut 12 in advance.

  The nut 12 of the feed screw 13 is connected via a belt 57 to a rotation shaft 55 a of a rotation driving device 55 fixed to the support column 59. By operating the rotation drive device 55 and rotating the nut 12 connected to the rotation shaft 55a via the belt 57, the screw shaft 11 fitted to the nut 12 can be moved up and down together with the support shafts 21 and 21. it can. In addition, as a drive device which rotates the nut 12, a well-known drive device, for example, what connected the nut and the rotating shaft of the rotation drive device via the gear etc. can be used.

  On the other hand, the linear motion bearings 23a and 23b are accommodated and fixed in cylindrical containers 54, respectively. Each container 54 is fixed to a support column 59.

  As described above, when using a conventional linear motion guide device having a structure in which a support shaft (shaft body) is slidably accommodated inside the outer cylinder, the support shaft is moved up and down (in the length direction). In order to move, for example, a linear motion drive device having a configuration in which a feed screw is connected to a rotation shaft of the rotation drive device is used. The feed screw is composed of a screw shaft connected to the rotary shaft and a nut fitted around the screw shaft. The nut of the feed screw of this linear motion drive device is connected to the support shaft of the linear motion guide device.

  For example, when this conventional linear motion guide device is incorporated in an electronic component mounting device, the feed shaft must be arranged in parallel with the support shaft of the linear motion guide device and the screw shaft of the feed screw of the linear motion drive device. A driving force in a direction inclined with respect to the length direction is applied to the support shaft through the nut of the screw, and the driving force necessary for the movement of the support shaft varies. For this reason, it becomes difficult to accurately move the support shaft to a predetermined position together with the electronic component held at the lower end thereof. For this reason, when using a conventional linear motion guide device, it is necessary to precisely adjust the positional relationship between the support shaft and the screw shaft (that is, the drive device for the support shaft). Moreover, in order to shorten the mounting time of an electronic component, the electronic component mounting apparatus may be provided with a plurality of support shafts including the suction nozzle. In such a case, it is not easy to precisely adjust the positional relationship between each support shaft and its driving device so that all the support shafts move with high accuracy in the length direction.

  On the other hand, in the linear motion guide device 10 of the present invention, the support shafts 21 and 21 supported by the linear motion bearings 23 a and 23 b are integrally formed as an extension of the screw shaft 11 of the feed screw 13. That is, in the linear motion guide device 10, the support shaft 21 is formed integrally with the screw shaft 11 that drives the support shaft 21. For this reason, when the linear motion guide device 10 is used, it is not necessary to precisely adjust the positional relationship between the support shaft and the drive device as described above when incorporating the linear motion guide device 10 in a mechanical device such as an electronic component mounting device. The connection between the support shaft 21 and the rotation driving device 55 can be easily performed. Further, the bending of the screw shaft 11 of the feed screw 13 can be effectively suppressed by supporting the support shafts 21 on both sides of the screw shaft 11 with the linear motion bearings 23a and 23b. For this reason, the linear motion guide device 10 of the present invention can move the support shaft (shaft body) 21 in the lengthwise direction with high accuracy by rotationally driving the nut 12 of the feed screw 13.

  FIG. 5 is a partially cutaway front view showing a configuration example of a linear motion guide device (both sides groove type) with a rotary bearing of the present invention and an aspect of its use.

  5 has a configuration in which two rotary bearings 43 and 43 are mounted around the outer cylinder 22 of each of the linear motion bearings 23a and 23b of the linear motion guide device 10 of FIG. have. The configuration of each rotary bearing 43 is the same as that of the rotary bearing 43 mounted around the nut 12 of the feed screw 13 of FIG.

  The feed screw 13 of the linear motion guide device 50 with the rotary bearing is accommodated in the cylindrical container 53 via the two rotary bearings 43 and 43 as in the case of the feed screw 13 of the linear motion guide device 10 of FIG. It is fixed. Further, the nut 12 of the feed screw 13 is connected via a belt 57 to a rotation shaft 55 a of a rotation drive device 55 fixed to the support column 59.

  On the other hand, the linear motion bearings 23a and 23b are housed and fixed in a cylindrical container 54 via two rotary bearings 43 and 43 mounted around the outer cylinder 22, respectively. Each container 54 is fixed to a support column 59.

  The outer cylinder 22 of the linear motion bearing 23 a is connected to a rotary shaft 56 a of a rotary drive device 56 fixed to the support column 59 via a belt 58. When the rotation driving device 56 is operated and the outer cylinder 22 connected to the rotation shaft 56a via the belt 58 is rotated, the outer cylinder 22 is supported together with the support shaft 21 supported and supported non-rotatably by the outer cylinder 22, that is, directly. The entire dynamic bearing 23 a can be smoothly rotated together with the support shaft 21. At this time, the nut 12 of the feed screw 13 has a relative position with respect to the screw shaft 11 using the rotary drive device 55 in order to prevent the screw shaft 11 from moving in the vertical direction caused by the rotation of the screw shaft 11 together with the support shaft 21. It is rotationally driven so as not to fluctuate. As a driving device for rotating the outer cylinder 22, a known driving device can be used as in the case of the driving device for rotating the nut 12 of the feed screw 13.

  The linear motion guide device 50 with a rotary bearing moves and / or moves the support shaft 21 with high stability and stability by rotationally driving the nut 12 of the feed screw 13 and / or rotationally driving the outer cylinder 22 of the linear motion bearing 23a. Can be rotated.

  Thus, the linear motion guide device of the present invention rotates the support shaft (shaft body) very easily by mounting two (or more) rotary bearings around the outer cylinder of the linear motion bearing. Since it is possible to add a function to be used, it is excellent in versatility.

  FIG. 6 is a partially cutaway front view showing another configuration example of the linear motion guide device (both side groove type) with a rotary bearing of the present invention and a mode of use thereof. However, in order to make it easy to understand that the rolling elements 85 of the rotary bearings 83 of the linear motion bearings 73a and 73b are disposed in the circumferential groove 72a of the outer cylinder 72, the rolling elements 85 are respectively provided on the left and right sides of the outer cylinder 72. (The same applies to the rotary bearings 93 of the feed screw 63). In the rotary bearing 83, the rolling elements 85 are held in the through holes 86 a of the annular cage 86 shown in FIG. 8 below, so that the rolling elements 85 are actually disposed on the left and right sides of the outer cylinder 72 at the same time. There is nothing. If annular retainers having through holes facing each other in the diametrical direction are used, rolling elements are simultaneously disposed on the left and right sides of the outer cylinder.

  FIG. 7 is an enlarged view of a portion in the vicinity of the linear motion bearing 73a shown in FIG. FIG. 8 is a plan view of the annular cage 86 of the lower rotary bearing 83 shown in FIG. 9 is a cross-sectional view of the annular cage 86 cut along the cutting line II-II entered in FIG.

  The configuration of the linear motion guide device 60 with the rotary bearing shown in FIGS. 6 to 9 is the same as that of FIG. 5 except that the configurations of the feed screw 63, the linear motion bearings 73a and 73b, the rotary bearings 83, and the rotary bearings 93 are different. This is the same as the linear motion guide device 50 with a rotary bearing. The feed screw 63, the support shafts 21 and 21, the linear motion bearings 73a and 73b, and the rotary bearings 93 and 93 constitute the linear motion guide device (both side groove type) of the present invention. The configuration of this linear motion guide device is the same as that of the linear motion guide device 10 of FIG. 4 except that the configurations of the feed screw 63 and the rotary bearings 93 are different.

  The configuration of the linear motion bearings 73a and 73b is the same as that of the linear motion bearings 23a and 23b in FIG. 5 except that the circumferential grooves 72a and 72a are formed on the outer peripheral surface of the outer cylinder 72, respectively.

  The diameter of the outer peripheral surface of the outer cylinder 72 is preferably constant in the length direction of the outer cylinder 72. Thereby, manufacture of the outer cylinder 72 provided with the circumferential groove 72a becomes very easy.

  Each rotary bearing 83 mounted around the outer cylinder 72 includes a circumferential groove 72a formed on the outer circumferential surface of the outer cylinder 72, a plurality of rolling elements 85 disposed in the circumferential groove 72a, and each rolling element 85. An annular retainer 86 that is rotatably held in a state of being partially projected to the circumferential side and the outer circumferential side, and a circumferential groove 87a that accommodates each rolling element portion projected to the outer circumferential side of the annular retainer 86 It is preferable that it is comprised from the annular body 87 with which a surrounding surface is equipped.

  The annular body 87 and the rolling element 85 are made of, for example, a metal material typified by steel. A spherical body is used as the rolling element 85. Rollers may be used instead of the spheres. The annular cage 86 is formed of a metal material or a resin material as in the case of the cylindrical cage 27.

  The annular cage 86 prevents contact between the adjacent rolling elements 85 and 85. Accordingly, wear of the rolling element 85 is suppressed, and the outer cylinder 72 of the linear motion bearing 73a is tightly supported by the annular body 87 via the plurality of rolling elements 85. Therefore, the support shaft 21 accommodated in the outer cylinder 72 is supported. Rotational movement with high accuracy is realized. Further, since the occurrence of relative fine movement in the axial direction between the annular body 87 and the outer cylinder 72 is suppressed, linear movement with high accuracy of the support shaft 21 accommodated in the outer cylinder 72 is realized. .

  When the linear motion bearings 73 a supported by these rotary bearings 83, 83 are rotated in the circumferential direction, the plurality of rolling elements 85 of each rotary bearing 83 roll along the circumferential groove 72 a of the outer cylinder 72. For this reason, the linear motion bearing 73a can smoothly rotate in the circumferential direction while being supported by the rotary bearings 83 and 83.

  Thus, in the linear motion guide device 60 with a rotary bearing, the circumferential groove 72a formed in the outer peripheral surface of the outer cylinder 72 of each linear motion bearing is used as the track of the plurality of rolling elements 85 of each rotary bearing 83. Yes. Such a circumferential groove 72a is formed by, for example, machining using a lathe or a cylindrical grinder, and the central axis of the circumferential groove 72a (that is, the central axis of the rotary bearing 83) and the central axis of the outer cylinder 72 (that is, each straight shaft). It is easy to form it in a state where it is exactly aligned with the center axis of the dynamic bearing. Then, by assembling the rotary bearing 83 by arranging a plurality of rolling elements 85 in the circumferential groove 72a on the outer peripheral surface of the outer cylinder 72, the central axis of each rotary bearing 83 is easily matched with the central axis of each linear bearing. Can be made. For this reason, the linear motion guide device 60 with a rotary bearing can rotate the support shaft 21 with stable and high accuracy without considering the accuracy of assembly.

  The number of rotary bearings to be mounted around the outer cylinder of each linear bearing is not particularly limited as long as it is two or more, but may be in the range of 2 to 4 because it is easy to assemble. Two are particularly preferable.

The annular cage 86 of each rotary bearing 83 includes a peripheral wall 86b arranged coaxially with the outer cylinder 72 in which a plurality of through holes 86a for holding the respective rolling elements 85 are formed. A plurality of slits 86c are formed in the peripheral wall 86b of the annular cage 86 of the upper rotary bearing 83 so as to reach the end surface of the other (lower side in FIG. 7) rotary bearing 83 from each through hole 86a. In the peripheral wall 86b of the annular cage 86 of the other (lower) rotary bearing 83, a plurality of slits 86c reaching the end surface of the one (upper) rotary bearing 83 from each through hole 86a. And the width (W ₁ ) of each slit 86c of each annular cage 86 is preferably within a range of 0.7 to 0.95 times the diameter of the rolling element 85. 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 fluctuates in the axial direction) Means the largest diameter).

  The annular retainer 86 has a plurality of rolling elements 85 disposed between the circumferential groove 87a of the annular body 87 and the circumferential groove 72a of the outer cylinder 72, and then the annular retainer 86 is connected to the annular body 87 from one end side of the annular body 87. It is inserted between the outer cylinder 72. When the annular cage 86 is inserted between the annular body 87 and the outer cylinder 72, each rolling element 85 is accommodated in the through hole 86a through the slit 86c.

As shown in FIGS. 8 and 9, the width (W ₂ ) of the end portion of each slit 86 c of the annular cage 86 opposite to the through hole 86 a side is larger than the width (W ₁ ). It is preferable. As a result, the rolling element 85 can easily enter the slit 86 c from the end portion, so that it becomes easier to accommodate the rolling element 85 in the through hole 86 a of the annular cage 86. The width (W ₂ ) of the end of the slit 86c opposite to the through hole 86a 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.

  It is preferable that an annular projecting portion 86d extending from the peripheral edge of the end portion to the inner peripheral side is provided at the end portion of the annular retainer 86 on the side opposite to the side where the slit 86c is formed. Thereby, the mechanical strength of the annular cage 86 is increased.

The difference between the diameter of the inner peripheral surface of the annular body 87 (FIG. 7: D ₁ ) and the diameter of the outer peripheral surface of the outer cylinder 72 (FIG. 7: D ₂ ) is 1.2 to 1.95 of the diameter of the rolling element 85. It is preferable that the length is within the range of double. Accordingly, a large gap is formed between the annular body 87 and the outer cylinder 72 by moving the annular body 87 in the radial direction of the outer cylinder 72. From the gap, the plurality of rolling elements 85 can be easily inserted between the annular body 87 and the circumferential groove 72a of the outer cylinder 72.

  If the difference between the diameter of the inner peripheral surface of the annular body 87 and the diameter of the outer peripheral surface of the outer cylinder 72 is 1.2 times or more the diameter of the rolling element 85, the gap becomes larger, so Easy to insert. On the other hand, when the difference between the diameter of the inner peripheral surface of the annular body 87 and the diameter of the outer peripheral surface of the outer cylinder 72 is 1.95 times or less than the diameter of the rolling element 85, each of the annular body 87 and the outer cylinder 72 Since the depth of the circumferential groove 72a can be made sufficiently large, the occurrence of the rolling elements 85 falling off between the circumferential grooves 72a is suppressed.

  The difference between the diameter of the inner peripheral surface of the annular body 87 and the diameter of the outer peripheral surface of the outer cylinder 72 is preferably a length in the range of 1.3 to 1.8 times the diameter of the rolling element 85. 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 order to reduce the size in the radial direction of the linear motion guide device 60 with the rotary bearing, the outer diameter of the rotary bearing 83, and thus the radial size of the annular body 87, the diameter of the rolling element 85, and the annular cage It is necessary to reduce the size of 86 in the radial direction. When the outer diameter of the rotary bearing 83 is reduced, the distance between the annular body 87 and the outer cylinder 72 is reduced, and thus the thickness of the annular cage 86 is also reduced. For this reason, the mechanical strength of the annular cage 86 is lowered.

  In order to suppress a decrease in the mechanical strength of the annular cage 86, the diameter of the outer peripheral surface of the outer cylinder 72 is the area from each end of the outer cylinder 72 to the circumferential groove 72a disposed adjacent to this end. It is preferable that the diameter of the outer peripheral surface of the outer cylinder 72 be constant over the entire length in the length direction of the outer cylinder 72 as described above.

  As a result, even when the inner diameter of the annular cage 86 is reduced within a range where the annular cage 86 does not contact the outer peripheral surface of the outer cylinder 72, that is, the thickness of the annular cage 86 is increased to increase its mechanical strength. Even if it is increased, the annular retainer 86 is arranged around the end of the outer cylinder 72 and is moved along the length direction of the outer cylinder 72 so that the annular body 87 and the outer cylinder 72 are moved. It becomes possible to insert between the circumferential groove 72a.

  The configuration of the feed screw 63 shown in FIG. 6 is the same as that of the feed screw 13 shown in FIG. 5 except that circumferential grooves 62 a and 62 a are formed on the outer peripheral surface of the nut 62.

  Each rotary bearing 93 mounted around the feed screw 63 includes a circumferential groove 62a formed on the outer circumferential surface of the nut 62, a plurality of rolling elements 85 disposed in the circumferential groove 62a, and an inner circumference around each rolling element 85. An annular retainer 86 that is rotatably held in a state of partially protruding to the outer and outer peripheral sides, and a circumferential groove 87a that accommodates each rolling element portion that protrudes to the outer peripheral side of the annular retainer 86 It is preferable that it is comprised from the annular body 87 with which a surface is equipped.

  As in the case of the circumferential groove 72a of the outer cylinder 72 of the linear motion bearing, the circumferential groove 62a of the nut 62 is formed by, for example, machining using a lathe or a cylindrical grinder, for example, the central axis of the circumferential groove 62a (that is, a rotary bearing). 93 and the central axis of the nut 62 (that is, the central axes of the feed screw 63 and the support shafts 21 and 21) can be easily formed. Then, by arranging a plurality of rolling elements 85 in the circumferential groove 62a on the outer peripheral surface of the nut 62 and assembling the rotary bearing 93, the central axis of the rotary bearing 93 can be easily combined with the central axis of the feed screw 63 and each support shaft 21. Can match. For this reason, the linear motion guide device 60 with a rotary bearing can move the support shaft 21 with high accuracy stably in the length direction without considering the accuracy of assembly. Note that if the center axis of the rotary bearing 93 and the center axis of the feed screw 63 do not exactly match, the nut 62 rotates eccentrically, so that the straightness of the support shaft 21 decreases.

For the same reason as in the case of the linear motion bearing 73a, the diameter of the outer peripheral surface of the nut 62 of the feed screw 63 is preferably constant in the length direction of the nut 62. The difference between the diameter of the inner peripheral surface of the annular body 87 of the rotary bearing 93 (FIG. 6: D ₃ ) and the diameter of the outer peripheral surface of the nut 62 (FIG. 6: D ₄ ) is 1. The length is preferably in the range of 2 to 1.95 times. A preferable aspect of the annular cage 86 of the rotary bearing 93 is the same as that of the annular cage 86 of the rotary bearing 83.

  FIG. 10 is a partially cutaway front view showing another configuration example of the linear motion bearing used in the linear motion guide device or the linear motion guide device with the rotary bearing of the present invention. However, the linear motion bearing 103 is shown in a state where rotary bearings 83 and 83 are mounted around the outer cylinder 102 and the support shaft 21 is accommodated and supported inside the outer cylinder 102. 11 is a cross-sectional view of the linear motion bearing 103 and the support shaft 21 cut along the cutting line III-III entered in FIG.

  The configuration of the linear motion bearing 103 is such that a plurality of rolling elements 25 interposed between the outer cylinder 102 and the support shaft 21 are partially protruded from the inner peripheral side and the outer peripheral side, respectively. A cylindrical holder 107 that is rotatably held is provided, and on the inner peripheral surface of the outer cylinder 102, each rolling element portion protruding to the outer peripheral side of the cylindrical holder 107 is accommodated. 7 is the same as the linear motion bearing 73a shown in FIG. 7 except that a plurality of grooves 102a formed along the length direction are provided.

  In the linear motion bearing 103, each rolling element 25 protruding toward the inner peripheral surface side of the cylindrical cage 107 engages with each groove 21 a of the support shaft 21, and protrudes toward the outer peripheral surface side of the cylindrical cage 107. Each rolling element 25 is engaged with the groove 102 a of the outer cylinder 102. Therefore, the support shaft 21 is accommodated and supported in the outer cylinder 102 of the linear motion bearing 103 in a non-rotating state in the circumferential direction and in a slidable state in the length direction.

  FIG. 12 is a partially cutaway front view showing another configuration example of the linear motion guide device of the present invention. FIG. 13 is an enlarged view of a portion in the vicinity of the linear motion bearing 123 shown in FIG. 14 is a cross-sectional view of the linear motion bearing 123 and the support shaft 121 cut along the cutting line IV-IV entered in FIG.

  A linear motion guide device (one-side groove type) 120 shown in FIGS. 12 to 14 includes a feed screw 13 including a screw shaft 11 and a nut 12 fitted around the screw shaft 11, and an extension of one end of the screw shaft 11. A support shaft 121 having a circular cross section formed, a linear motion bearing 123 having an outer cylinder 22 that slidably accommodates and supports the support shaft 121 via a plurality of rolling elements 25 disposed on the outer peripheral surface thereof; A support shaft 21 having a plurality of grooves 21 a and 21 a formed along the length direction on the outer peripheral surface, which is formed as an extension of the other end of the screw shaft 11, and the support shaft 21. It is composed of a linear motion bearing 23a having an outer cylinder 22 that is accommodated and supported so as to be slidable in a non-rotating manner through a plurality of rolling elements that engage with each groove 21a.

  The configuration of the linear motion guide device 120 is the same as that of the linear motion guide device 10 in FIG. 1 except that one support shaft 121 has a circular cross section (no groove).

  The configuration of the linear motion bearing 123 is the same as that of the linear motion bearing 23b. However, since no groove is formed on the outer peripheral surface of the support shaft 121, the plurality of rolling elements 25 of the linear bearing 123 do not engage with the groove of the support shaft. For this reason, the support shaft 121 is accommodated and supported inside the outer cylinder 22 of the linear motion bearing 123 in a state in which the support shaft 121 can rotate in the circumferential direction and can slide in the length direction.

  In the linear motion guide device 120, rotation of the support shaft 121 in the circumferential direction is prevented by a linear motion bearing 23 a attached to the support shaft 21 formed integrally with the support shaft 121 via the screw shaft 11.

  The linear motion guide device 120 can also easily connect the support shaft (shaft body) and the drive device when the device is incorporated in a mechanical device such as an electronic component mounting device. It can be moved with high accuracy in a stable direction. The linear motion guide device 120 can be added with a function of rotating the support shaft very easily by mounting two (or more) rotary bearings around the outer cylinder of each linear motion bearing. Therefore, it is excellent in versatility.

  In place of the linear motion bearing 123, the support shaft is accommodated and supported so as to be slidable (in a rotatable state in the circumferential direction) via a plurality of rolling elements disposed on the outer peripheral surface thereof. A known linear motion bearing having an outer cylinder can be used.

  Then, by mounting two (or more) rotary bearings around the outer cylinder of each linear bearing of the linear guide device 120, the linear guide device with the rotary bearing of the present invention (one-side groove type). Can be configured.

  Since the preferred mode of the linear guide device of the single-side groove type and the linear guide device with a rotary bearing is the same as that of the double-side groove type, further explanation is omitted.

DESCRIPTION OF SYMBOLS 10 Linear motion guide apparatus 11 Screw shaft 12 Nut 13 Feed screw 19 Through-hole 21 Support shaft 21a Groove 22 Outer cylinder 22a Annular groove 23a, 23b Linear motion bearing 24 Opening part 25 Rolling element 26 Rolling element circulation path 26a Rolling element protrusion groove 26b Connecting groove 27 Cylindrical cage 28 Retaining ring 43 Rotating bearing 44 Inner circumferential annular body 44a Circumferential groove 45 Rolling body 46 Annular cage 47 Outer circumferential annular body 47a Circumferential groove 50 Linear motion guide device with rotary bearing 51 Exhaust pipe 52 Connection Member 52a Gas passage 53, 54 Container 55, 56 Rotation drive device 55a, 56a Rotating shaft 57, 58 Belt 59 Strut 60 Linear motion guide device with rotary bearing 62 Nut 62a Circumferential groove 63 Feed screw 72 Outer cylinder 72a Circumferential groove 73a, 73b Linear motion bearings 83, 93 Rotary bearings 85 Rolling elements 86 Annular cage 86a Through holes 86b Peripheral walls 8 c the inner peripheral surface of the diameter of the slit 86d annular protrusion 87 annular body 87a peripheral groove 102 outer cylinder 102a grooves 103 linear bearing 107 cylindrical retainer 120 linear guide apparatus 121 support shaft 123 linear bearing D ₁ annulus 87 D ₂ opposite to the side of the outer peripheral surface of the diameter W ₁ slit 86c having a width W ₂ slit 86c of the through hole 86a with a diameter D ₄ nut 62 of the inner peripheral surface of the diameter D ₃ annular body 87 of the outer peripheral surface of the outer tube 72 End width

Claims (13)

A feed screw comprising a screw shaft and a nut fitted around the screw shaft, a support shaft having a circular cross section formed as an extension of one end of the screw shaft, and the support shaft disposed on the outer peripheral surface thereof. A linear motion bearing having an outer cylinder that is slidably received and supported via a plurality of rolling elements, and is formed as an extension of the other end of the screw shaft along the longitudinal direction Linear motion having a support shaft having a plurality of grooves formed in the above-described manner, and an outer cylinder that accommodates and supports the support shaft in a non-rotatably slidable manner via a plurality of rolling elements that engage with the grooves. Linear motion guide device consisting of bearings . 2. The linear motion guide device according to claim 1, wherein two or more rotary bearings are mounted around a nut of the feed screw . Each rotary bearing mounted around the nut has a circumferential groove formed on the outer peripheral surface of the nut, a plurality of rolling elements arranged in the circumferential groove, and each rolling element is divided into an inner circumferential side and an outer circumferential side. The annular cage is rotatably held in a state of being protruded, and the annular body is provided with a circumferential groove on the inner circumferential surface for accommodating each rolling element portion projected to the outer circumferential side of the annular cage. The linear motion guide device according to claim 2 . The linear motion guide device according to claim 3, wherein a diameter of an outer peripheral surface of the nut is constant in a length direction of the nut . The difference between the diameter of the inner peripheral surface of the annular body of each rotary bearing mounted around the nut and the diameter of the outer peripheral surface of the nut is within a range of 1.2 to 1.95 times the diameter of the rolling element. The linear motion guide device according to claim 3 or 4 . An annular cage of each rotary bearing mounted around the nut includes a peripheral wall arranged coaxially with the nut in which a plurality of through holes for holding the rolling elements are formed. The circumferential wall of the annular cage is formed with a plurality of slits that reach the end surface of the other rotary bearing from the respective through holes. The circumferential wall of the annular cage of the other rotary bearing is provided with each of the through holes. A plurality of slits reaching the end surface of the one rotary bearing from the hole are formed, and the width of each slit of each annular cage is within a range of 0.7 to 0.95 times the diameter of the rolling element. The linear motion guide device according to any one of claims 3 to 5, wherein the linear motion guide device has a length of . The linear motion guide device according to any one of claims 1 to 6, wherein a through hole is formed on a central axis of the screw shaft and each support shaft . The linear motion guide device according to claim 7, which is used for an electronic component mounting device . A linear motion guide device with a rotary bearing, wherein two or more rotary bearings are mounted around the outer cylinder of each linear motion bearing of the linear motion guide device according to any one of claims 1 to 8. . Each rotary bearing mounted around the outer cylinder includes a circumferential groove formed on the outer circumferential surface of the outer cylinder, and the circumferential groove
A plurality of rolling elements arranged in a ring, an annular cage that holds each rolling element in a state of partially projecting to the inner and outer circumferential sides, and an outer circumferential side of the annular cage. The linear motion guide device with a rotary bearing according to claim 9, wherein the linear motion guide device is provided with an annular body having an inner peripheral surface with a circumferential groove that accommodates each rolling element portion . The linear motion guide device with a rotary bearing according to claim 10, wherein a diameter of an outer peripheral surface of the outer cylinder is constant in a length direction of the outer cylinder . The difference between the diameter of the inner peripheral surface of the annular body of each rotary bearing mounted around the outer cylinder and the diameter of the outer peripheral surface of the outer cylinder is in the range of 1.2 to 1.95 times the diameter of the rolling element. The linear guide device with a rotary bearing according to claim 10 or 11, wherein the linear guide device has a length . An annular cage of each rotary bearing mounted around the outer cylinder is provided with a peripheral wall arranged coaxially with the outer cylinder in which a plurality of through holes are formed to hold the rolling elements. The peripheral wall of the annular cage of the bearing is formed with a plurality of slits that reach the end face on the other rotary bearing side from each through hole, and the peripheral wall of the annular cage of the other rotary bearing A plurality of slits reaching the end surface of the one rotary bearing from each through hole are formed, and the width of each slit of each annular cage is 0.7 to 0.95 times the diameter of the rolling element. The linear motion guide device with a rotary bearing according to any one of claims 10 to 12, wherein the linear motion guide device has a length within a range .

Images