JP2010203465A - Linear motion bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a linear motion bearing capable of increasing the effective ball number and easy to miniaturize. <P>SOLUTION: This linear motion bearing is composed of an outer cylinder (11), a cylindrical sphere cage (16) respectively formed at an interval in the peripheral direction on an outer peripheral surface of a cylindrical body part (12) fitted to the inside of this outer cylinder and having a plurality of sphere circulating grooves (15) having a slender opening (14) capable of partially projecting a sphere to the inner peripheral side, and a plurality of spheres (17) stored in the respective sphere circulating grooves. The linear motion bearing is characterized in that a peripheral groove (11a) is mutually formed at an interval on an inner peripheral surface of the outer cylinder, and an extension part (13) having an outer diameter smaller than an inner diameter of the outer cylinder, is respectively provided on both ends of a body part of the cylindrical sphere cage, and an annular fastener (19) is stored in its outer peripheral part in the respective peripheral grooves, and the movement in the length direction of the outer cylinder of the cage, is prevented by arranging an inner peripheral part in contact with a base part (13a) of the respective extension parts of the body part of the cylindrical sphere cage. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a linear motion bearing that can be advantageously used to support a shaft that is linearly driven.

  Linear motion bearings are used to support shafts that are linearly driven in various industrial machines.

  FIG. 15 is a partially cutaway perspective view showing a configuration example of a conventional linear motion bearing. However, FIG. 15 shows the linear motion bearing 60 in a state where the shaft body 68 is supported.

  The linear motion bearing 60 of FIG. 15 is formed on the outer peripheral surface of the outer cylinder 61 and the cylindrical barrel portion 62 fitted inside the outer cylinder 61 at intervals along the circumferential direction. A cylindrical sphere holder 66 having a plurality of sphere circulation grooves 65, 65,... Having elongated openings capable of partially protruding the sphere (however, the opening is formed at the bottom of the linear groove 65a of the sphere circulation groove 65). And a plurality of spheres 67, 67,... Accommodated in each sphere circulation groove 65. A linear motion bearing having such a configuration is described in Patent Document 1, for example.

  The cylindrical spherical body holder 66 of the linear motion bearing 60 accommodates a shaft body 68 to be supported. As described above, the shaft body 68 is supported by the sphere body 67 that protrudes inward from the opening of each sphere circulation groove 65 of the cylindrical sphere holder 66. When the shaft body 68 is moved in the length direction, the sphere 67 that supports the shaft body 68 circulates and moves inside the sphere circulation groove 65.

  In addition, circumferential grooves 61 a and 61 a are formed on the inner peripheral surface of the outer cylinder 61 at intervals. Each peripheral groove 61a accommodates an outer peripheral portion of an annular stopper (referred to as a retaining ring or snap ring) 69. And the inner peripheral part of each annular stopper 69 is arranged in contact with each end face of the body part 62 of the cylindrical sphere holder 66, so that the movement of the holder 66 in the length direction of the outer cylinder 61 is performed. It is prevented.

JP 2004-28192 A (FIG. 19)

In the linear motion bearing 60 of FIG. 15, if the length of the cylindrical sphere cage 66 is the same, the ratio (L _G ) of the length (L _G ) of the sphere circulation groove 65 to the length (L _R ) of the cage 66. _{As G} / L _R ) increases, the number of spheres 67 that contact both the outer cylinder 61 and the shaft body 68 and support the shaft body 68 (hereinafter referred to as “effective ball number”) increases. Loadability is improved.

Further, if the load resistance is maintained (the same number of effective balls is ensured) and the length of the spherical circulation groove 65 is not changed, the shorter the length of the cylindrical spherical cage 66, that is, the cage As the ratio (L _G / L _R ) of the length (L _G ) of the spherical circulation groove 65 to the length (L _R ) of 66 increases, the size of the linear motion bearing 60 decreases.

  However, for example, when the shaft body 68 of the linear bearing 60 moves at a high speed, the sphere 67 accommodated in each sphere circulation groove 65 also moves at a high speed. For this reason, a large force is applied to the side wall surfaces at both ends of each sphere circulation groove 65 from the sphere 67 that moves at high speed. Accordingly, reinforcing portions 66a having a length of a certain length or more are provided on both outer sides of each spherical circulation groove 65 of the cylindrical spherical cage 66 so that the side wall surface is not deformed by the force applied from the spherical body 67. There is a need.

Therefore, in the conventional linear bearing 60, when the ratio of the length of the spherical circulation groove 65 to the length of the cylindrical spherical cage 66 (L _G / L _R ) is increased, the length (L _{Since S} ) is reduced, the strength of the cage 66 is reduced. For this reason, it is difficult to further increase the number of effective balls of the linear motion bearing 60 or to further reduce the size of the linear motion bearing 60.

  An object of the present invention is to provide a linear motion bearing that can increase the number of effective balls and that can be easily reduced in size.

The present invention is formed on the outer peripheral surface of the outer cylinder and the cylindrical body part fitted inside the outer cylinder with a space along the circumferential direction, and a partial protrusion of a sphere is formed on the inner peripheral side. A cylindrical sphere holder having a plurality of spherical circulation grooves with possible elongated openings, and a linear motion bearing comprising a plurality of spheres accommodated in each spherical circulation groove,
Circumferential grooves are formed at intervals on the inner peripheral surface of the outer cylinder, and extensions having an outer diameter smaller than the inner diameter of the outer cylinder are provided at both ends of the body of the cylindrical sphere retainer. An annular stopper is accommodated at the outer peripheral portion of each circumferential groove of the outer cylinder, and the inner peripheral portion of the base portion or the trunk portion of each extension portion of the cylindrical sphere cage is provided. The linear motion bearing is characterized in that movement of the retainer in the length direction of the outer cylinder is prevented by being arranged in contact with each end face.

Preferred embodiments of the linear motion bearing of the present invention are as follows.
(1) The shape of the cross section perpendicular to the circumferential direction of the annular stopper is circular.
(2) The annular stopper has a C-shape that is partially discontinuous.
(3) The surface of the base portion of each extension portion forms a curved surface.

  The present invention also provides a cylindrical spherical cage of the linear motion bearing according to the present invention, wherein the shaft body is accommodated in contact with a spherical body protruding from the opening of each spherical circulation groove of the cage to the inner peripheral side. There is also a motion guide device.

  In the linear motion bearing of the present invention, the inner peripheral portion of each annular stopper accommodated in the circumferential groove of the outer cylinder is placed in contact with the base of each extension portion of the barrel portion of the cylindrical sphere cage or the end surface of the barrel portion. By doing so, the movement of the retainer in the length direction of the outer cylinder is prevented. For this reason, if the linear motion bearing of the present invention exhibits the same load resistance as that of the conventional linear motion bearing (ensures the same number of effective balls), each extension that reinforces the cylindrical sphere cage Since the portion can be accommodated and arranged at a position on the inner peripheral side of each annular stopper that supports and fixes the retainer, it can be produced in a smaller size. Moreover, if the outer cylinder of the same length as the outer cylinder of the conventional linear bearing is used for the linear bearing of the present invention, a cylindrical sphere cage having a longer length is formed inside the outer cylinder, that is, The cylindrical sphere cage having a longer sphere circulation groove can be accommodated and fixed to increase the number of effective balls, so that the load resistance can be improved.

It is a figure which shows the structural example of the linear motion bearing of this invention. However, the linear motion bearing 10 is shown in a state where the shaft body 18 is accommodated in the cylindrical sphere holder 16. It is sectional drawing of the linear motion bearing 10 cut | disconnected along the cutting line II-II line entered in FIG. It is sectional drawing of the linear motion bearing 10 cut | disconnected along the cutting line III-III line entered in FIG. It is sectional drawing of the linear motion bearing 10 cut | disconnected along the cutting line IV-IV line entered in FIG. It is the figure which looked at the cylindrical sphere holder | retainer 16 shown in FIG. 2 from the left side of the figure. It is the figure which looked at the cylindrical sphere holder 16 of FIG. 5 from the right side of the figure. It is sectional drawing of the cylindrical sphere holder | retainer 16 cut | disconnected along the cutting line VII-VII line written in FIG. It is a figure which shows the path | route which the spherical body 17a shown in FIG. 1 moves. It is the figure which looked at FIG. 8 from the right side of the figure. However, the shaft body 18 is written in a state of being cut along its central axis. It is the figure which looked at FIG. 8 from the upper side of the figure. FIG. 10 is a diagram showing a path along which a sphere 77a corresponding to the sphere 17a shown in FIG. 8 moves in a conventional linear motion guide device having a shaft with a groove. It is the figure which looked at FIG. 11 from the right side of the figure. It is the figure which looked at FIG. 11 from the upper side of the figure. It is sectional drawing which shows another structural example of the linear motion bearing of this invention. It is a partially notched perspective view which shows the structure of the conventional linear motion bearing. However, the linear motion bearing 60 is shown in a state where the shaft body 68 is accommodated in the cylindrical sphere holder 66.

  A linear motion bearing according to the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a diagram showing a configuration example of a linear motion bearing according to the present invention. FIG. 2 is a cross-sectional view of the linear motion bearing 10 cut along the cutting line II-II entered in FIG. FIG. 3 is a cross-sectional view of the linear motion bearing 10 cut along the cutting line III-III entered in FIG. 4 is a cross-sectional view of the linear motion bearing 10 cut along the cutting line IV-IV entered in FIG.

  FIG. 5 is a view of the cylindrical sphere holder 16 shown in FIG. 2 as viewed from the left side of the figure. FIG. 6 is a view of the cylindrical sphere holder 16 of FIG. 5 as viewed from the right side of the figure. 7 is a cross-sectional view of the cylindrical sphere holder 16 cut along the cutting line VII-VII written in FIG.

  The linear motion bearing 10 shown in FIGS. 1-7 is formed in the outer cylinder 11 and the outer peripheral surface of the cylindrical trunk | drum 12 currently fitted by the inner side of the outer cylinder 11 at intervals along the circumferential direction, A cylindrical sphere holder 16 having a plurality of sphere circulation grooves 15, 15, having elongated openings 14 capable of partially protruding the sphere on the inner peripheral side, and each of the sphere circulation grooves 15 is accommodated. It consists of a plurality of spheres 17, 17,. The linear bearing 10 has circumferential grooves 11a and 11a formed on the inner peripheral surface of the outer cylinder 11 with a space therebetween, and is formed at each end of the body 12 of the cylindrical sphere holder 16. An extension 13 having an outer diameter smaller than the inner diameter of the outer cylinder 11 is provided, and an annular stopper 19 is accommodated in the outer circumferential portion of each circumferential groove 11a of the outer cylinder 11, and the inner circumferential portion Is disposed in contact with the base portion 13a of each extension portion 13 of the body portion 12 of the cylindrical sphere holder 16 so that the movement of the retainer 16 in the length direction of the outer cylinder 11 is prevented. There is a special feature.

  As shown in FIG. 4, a plurality of recesses 11 b are formed on the inner peripheral surface of the outer cylinder 11. On the other hand, a plurality of convex portions 16b are formed on the outer peripheral surface of the cylindrical sphere holder 16 as shown in FIG. Since the concave portion 11b of the outer cylinder 11 and the convex portion 16b of the cylindrical sphere holder 16 are engaged, rotation of the cylindrical sphere holder 16 in the circumferential direction is prevented.

  The outer cylinder 11 is usually formed from a metal material typified by steel (eg, stainless steel). In addition, a resin material can be used to reduce the weight of the outer cylinder, and a ceramic material can be used to improve the heat resistance and corrosion resistance of the outer cylinder.

  The body 12 of the cylindrical sphere holder 16 is fitted inside the outer cylinder 11. A plurality of spherical circulation grooves 15, 15,... Are formed on the outer peripheral surface of the body 12 at intervals along the circumferential direction.

  As shown in FIG. 6, each sphere circulation groove 15 includes a linear groove 15a having an elongated opening 14 on the inner peripheral side that can partially project the sphere, and connecting grooves 15c and 15c at both ends of the linear groove 15a. It is comprised from the linear groove | channel 15b connected via.

  The number of the spherical circulation grooves 15 is preferably in the range of 2 to 10. If the number of spherical circulation grooves is one, the shaft body 18 accommodated in the cylindrical spherical holder 16 cannot be supported. On the other hand, if the number of spherical circulation grooves exceeds 10, it is retained. The structure of the cage 16 becomes complicated, and the strength of the cage 16 decreases because the spherical circulation grooves are formed densely. In order to stably support the shaft body 18 with the sphere 17 protruding from the opening 14 of each sphere circulation groove 15, the number of sphere circulation grooves is more preferably in the range of 3 to 10.

  The cylindrical sphere holder 16 is made of, for example, a metal material or a resin material. Examples of the resin material include polyacetal resin, polyphenylene sulfide (PPS) resin, polyamide resin (nylon: registered trademark) polyetheretherketone (PEEK) resin, and fluorine resin. The cylindrical sphere cage 16 can be manufactured by molding the resin material by various molding methods (eg, injection molding method, compression molding method, casting method, etc.), for example.

  A plurality of spheres 17, 17,... Are accommodated in each sphere circulation groove 15 of the cylindrical sphere holder 16. The sphere 17 is made of, for example, a metal material typified by steel or a ceramic material.

  The cylindrical sphere holder 16 accommodates a shaft body 18 to be supported in contact with a sphere 17 protruding from the opening 14 of each sphere circulation groove 15 of the holder 16 to the inner peripheral side. When the shaft 18 is moved in the length direction, the plurality of spheres 17 accommodated in the straight grooves 15 a of the sphere circulation grooves 15 are rolled between the outer cylinder 11 and the shaft 18. It moves and circulates inside the spherical circulation groove 15. Thereby, the shaft 18 is smoothly moved in the length direction in a state where the shaft 18 is supported by the sphere 17 protruding from the opening 14 of each sphere circulation groove 15 to the inner peripheral side. The function of the planar zone 18a formed on the outer peripheral surface of the shaft body 18 will be described in detail later.

  As shown in FIGS. 1 to 7, in the linear motion bearing 10 of the present invention, circumferential grooves 11 a and 11 a are formed on the inner circumferential surface of the outer cylinder 11 at intervals. Further, extension portions 13 and 13 having outer diameters smaller than the inner diameter of the outer cylinder 11 are provided at both ends of the body 12 of the cylindrical sphere holder 16. As shown in FIG. 3, an annular stopper 19 is accommodated in each peripheral groove 11 a of the outer cylinder 11 at the outer peripheral portion, and the inner peripheral portion is an extension of the trunk portion 12 of the cylindrical sphere holder 16. By being disposed in contact with the 13 base portions 13 a, the retainer 16 is prevented from moving in the length direction of the outer cylinder 11.

  Thus, if the movement of the cylindrical sphere holder 16 in the length direction of the outer cylinder 11 is prevented by the annular stopper 19 arranged in contact with the base portion 13a of each extension portion 13 of the holder 16, it will be described below. As described above, it is possible to increase the number of effective balls that support the shaft body 18 to improve the load resistance of the linear motion bearing 10 or to reduce the size of the linear motion bearing 10.

  As described above, in the conventional linear motion bearing 60 shown in FIG. 15, the side wall surfaces at both ends of each sphere circulation groove 65 of the cylindrical sphere holder 66 are held so as not to be deformed by the force applied from the sphere 67. It is necessary to provide reinforcing portions 66 a and 66 a on both outer sides of the spherical circulation groove 65 of the vessel 66.

  On the other hand, in the linear motion bearing 10 of the present invention, as shown in FIG. 3, each extension portion 13 of the cylindrical sphere holder 16 functions as the reinforcing portion. Therefore, in the linear motion bearing 10 of the present invention, a spherical circulation groove 15 having a longer length than that of the conventional linear motion bearing is formed between the extensions 13 and 13 of the cylindrical spherical cage 16. be able to. Note that the spherical circulation groove may be formed to extend to the outer peripheral surface of each extension portion 13.

  Therefore, the linear motion bearing 10 of the present invention reinforces the cylindrical sphere cage 16 as long as the same load resistance as that of the conventional linear motion bearing is exhibited (the same number of effective balls is ensured). Since the extension portion 13 can be accommodated and disposed at the position on the inner peripheral side of each annular stopper 19 that supports and fixes the cage 16, the extension portion 13 can be manufactured in a smaller size.

  Moreover, if the linear cylinder 10 of this invention uses the outer cylinder of the same length as the outer cylinder of the conventional linear bearing, inside this outer cylinder, a cylindrical sphere holder with a longer length, That is, the cylindrical sphere cage having a longer sphere circulation groove can be accommodated and fixed to increase the number of effective balls, so that the load resistance can be improved.

  The annular stopper 19 is preferably formed from a material exhibiting elasticity such as a resin material or a metal material.

  In order to facilitate the accommodation arrangement of the outer cylinder 11 in the circumferential groove 11a of the annular stopper 19, as shown in FIG. preferable. Such an annular stopper 19 is applied with a force from the outer peripheral edge side and is elastically deformed so that the outer diameter thereof is reduced, so that the outer cylinder 11 is opened from the end opening of the outer cylinder 11. Inserted inside. When the annular stopper 19 reaches the circumferential groove 11a of the outer cylinder 11, it returns to its original shape and is accommodated and disposed in the circumferential groove 11a. The annular stopper may be set in a continuous annular shape. The annular stopper having such a shape can be accommodated and disposed in the circumferential groove of the outer cylinder by press-fitting it into the outer cylinder from the opening at the end of the outer cylinder.

  Further, as shown in FIG. 3, when the surface of the base portion 13a of each extension 13 of the cylindrical sphere holder 16 forms a curved surface, the annular stopper 19 is moved along the curved surface of the base portion 13a. However, it can be easily accommodated in the circumferential groove 11 a of the outer cylinder 11. Moreover, since the thickness (thickness of the left-right direction in FIG. 3) of the wall part of the outer side of the spherical circulation groove | channel 15 of the cylindrical sphere holder | retainer 16 becomes large, the intensity | strength of this holder | retainer 16 can be enlarged.

  Furthermore, as shown in FIG. 3, it is preferable that the shape of the cross section perpendicular | vertical to the circumferential direction of the annular stopper 19 is circular. Such an annular stopper 19 can be easily manufactured, for example, by bending a metal wire having a circular cross section.

  The linear motion bearing 10 of the present invention described with reference to FIGS. 1 to 7 has the number of effective balls (the number of spheres protruding from the openings 14 of the sphere circulation grooves 15 to support the shaft body 18). For example, when the number is set to three, the length of the outer cylinder 11 can be set to 6.5 mm, and the outer diameter can be set to 7 mm. Thus, according to the present invention, it is possible to provide an extremely small linear motion bearing.

  FIG. 14 is a cross-sectional view showing another configuration example of the linear motion bearing of the present invention. In the configuration of the linear motion bearing 20 in FIG. 14, the movement of the cylindrical sphere holder 36 in the length direction of the outer cylinder 11 is arranged in contact with each end surface 32 a of the body portion 32 provided with the extension portion 33. Except for being prevented by the annular stopper 19, it is the same as the linear motion bearing 10 shown in FIGS. 1 to 7.

  As described above, in the linear motion bearing of the present invention, the movement of the cylindrical spherical cage in the length direction of the outer cylinder is caused by the surface of the step formed by the trunk portion and the extension portion of the cage (the extension portion). This is prevented by placing an annular stopper in contact with the end face of the base part or the body part.

  Next, the linear motion guide device of the present invention will be described.

  The linear motion guide device of the present invention is accommodated in the cylindrical sphere cage of the linear motion bearing of the present invention in a state where the shaft body is in contact with the sphere projecting inward from the opening of each spherical circulation groove of the cage. It is constituted by doing. That is, the linear motion bearing 10 described with reference to FIGS. 1 to 7 and the shaft body 18 supported by the linear motion bearing 10 constitute the linear motion guide device of the present invention.

  As shown in FIGS. 1 to 4, the shaft body of the linear motion guide device of the present invention is a shaft body at a position corresponding to the opening 14 of each sphere circulation groove 15 of the cylindrical sphere holder 16 on the outer peripheral surface. It is preferable to use a cylindrical shaft body 18 in which a planar zone 18a extending in the length direction is formed.

  Thus, when the shaft body 18 is provided with the planar band 18a, the rotation of the shaft body 18 in the circumferential direction is caused by the engagement between the planar band 18a and the sphere 17 protruding from the opening 14 of the sphere circulation groove 15. It becomes possible to suppress.

  As shown in FIG. 4, the planar band 18 a of the shaft body 18 and the inner peripheral surface of the outer cylinder 11 at the center position in the width direction of the linear groove 15 a of the spherical circulation groove 15 (position indicated by the arrow P in the drawing). Is equal to the diameter of the sphere 17. If the shaft body 18 is rotated in the circumferential direction in a state where the spherical body 17 is not accommodated in the linear groove 15a, the planar band 18a of the shaft body 18 is relatively relative to the arrangement shown in FIG. It moves in the circumferential direction of the shaft 18 while tilting. That is, the distance between the planar band 18 a and the inner peripheral surface of the outer cylinder 11 at the position indicated by the arrow P is shorter than the diameter of the sphere 17. Therefore, when the sphere 17 is accommodated in the linear groove 15 a, the movement of the planar band 18 a is prevented by the sphere 17. For this reason, rotation of the shaft body 18 in the circumferential direction is suppressed.

  In addition to the effect of suppressing the rotation of the shaft body 18 in the circumferential direction as described above, the linear motion bearing of the present invention including the shaft body 18 further exhibits the excellent effects described below.

  FIG. 8 shows a path through which the sphere 17a shown in the drawing moves in the sphere circulation groove 15 in the linear motion guide apparatus (the apparatus constituted by the linear motion bearing 10 and the shaft body 18) of the present invention shown in FIG. FIG. However, only the shaft 18 and the sphere 17a are shown in FIG. 8 in order to facilitate understanding of the movement path of the sphere 17a. 9 is a view of FIG. 8 viewed from the right side of the figure, and FIG. 10 is a view of FIG. 8 viewed from the upper side of the figure. In addition, the arrow 21 written in these figures indicates the locus of the center of the moving sphere 17a.

  On the other hand, FIG. 11 shows a conventional linear motion guide device (having the same configuration as the device composed of the linear motion bearing 60 and the shaft body 68 shown in FIG. 15) provided with a shaft body having a groove. It is a figure which shows the path | route which the sphere 77a corresponding to the sphere 17a shown in FIG. 12 is a view of FIG. 11 viewed from the right side of the drawing, and FIG. 13 is a view of FIG. 11 viewed from the upper side of the drawing. In addition, the arrow 71 written in these figures has shown the locus | trajectory of the center of the moving sphere 77a.

  First, a path along which the sphere of such a linear motion guide device moves inside the sphere circulation groove of the cylindrical sphere holder will be described. For example, in the linear motion guide device of the present invention, a sphere that supports the shaft, that is, a sphere that is accommodated in the linear groove 15a of the cylindrical sphere holder 16 in FIG. When it moves (rolls) to one of the ends, it pivots in the connecting groove 15c connected to this end and moves to the linear groove 15b. Such a turning movement of the sphere is similarly performed in a conventional linear motion guide apparatus including a shaft body having a groove.

However, as shown in FIGS. 11 to 13, in the conventional linear motion guide device including the shaft body 78 having the groove 78 a, in order to turn the sphere 77 a, first, the sphere 77 a is moved to the groove 78 a of the shaft body 78. That is, the sphere 77a is moved from the position indicated by the arrow B ₀ shown in the drawing to the position indicated by the arrow B ₁ (as shown in FIG. 11, it moves upward at a distance ΔH corresponding to the depth of the groove 78a. It is necessary to turn the sphere 77a as shown in FIG. That is, as shown in FIGS. 11 to 13, the sphere 77a turns in order by sequentially passing through the positions indicated by the arrows B ₀ , B ₁ , B ₂ , and B ₃ .

However, a sphere that moves from the position indicated by the arrow B ₀ to the position indicated by the arrow B ₁ , that is, a sphere that moves within the distance ΔL shown in FIGS. 12 and 13, is a shaft 78 as shown in FIG. Since it moves toward the outside of the groove 78a (in a direction away from the shaft body 78), it is not used for supporting the shaft body 78. That is, the trajectory of the sphere within the range of the distance ΔL is not provided to support the shaft body with the sphere, but is provided to take out the sphere from the groove 78a of the shaft body 78 before the turning movement. It is what was done.

On the other hand, as shown in FIGS. 8 to 10, in the linear motion guide device of the present invention including the shaft body 18 having the planar band 18 a, it is necessary to move the sphere 17 a to the outside of the groove before the turning movement. And can be swung immediately. That is, the sphere 17a turns by sequentially passing through the positions indicated by the arrows A ₁ , A ₂ , and A ₃ shown in the figure.

Thus, the length of the sphere circulation groove required for the turning movement of the sphere is the total length of the distance L and the distance ΔL shown in FIGS. 12 and 13 in the conventional linear motion guide device. On the other hand, in the linear motion guide device of the present invention, the length of the distance L shown in FIGS. That is, in the linear motion guide device of the present invention, the length of the spherical circulation groove required for the rotational movement of the spherical body can be shortened by the length of the distance ΔL. As shown in FIG. 6, since the sphere 17 pivots in each connection groove 15 c of the sphere circulation groove 15 of the cylindrical sphere holder 16, the sphere circulation groove 15 is used in the linear motion guide device of the present invention. The length (L _G ) can be shortened by a length twice as long as the distance ΔL as compared with the case of the conventional linear motion guide device.

  Accordingly, the linear motion guide device of the present invention shown in FIGS. 1 to 4 is a spherical circulation groove as long as it exhibits the same load resistance as the conventional linear motion guide device (ensures the same number of effective balls). 15 can be shortened by a length twice as long as the distance ΔL shown in FIGS. 12 and 13, so that the size can be reduced (the cylindrical sphere holder 16 including the sphere circulation groove 15 is accommodated). It is easy to shorten the length of the outer cylinder 11 to be performed).

  Further, in this linear motion guide device, if the length of the spherical circulation groove 15 is set to be the same as the length of the spherical circulation groove of the conventional linear motion guide device, the number of effective balls that support the shaft body 18 Therefore, the load resistance can be improved.

  As described above, in the linear motion guide device of the present invention shown in FIGS. 1 to 4, the rotational movement of the shaft body in the circumferential direction is suppressed, the number of effective balls can be increased, and the size can be reduced. Easy.

  As the shaft body of the linear motion guide device of the present invention, a cylindrical shaft body or a shaft body having a groove can be used as in the case of the linear motion guide device shown in FIG.

  For example, the linear motion guide device of the present invention configured by accommodating a cylindrical shaft body in the cylindrical spherical cage of the linear motion bearing 10 shown in FIG. 1 does not require machining to form a groove in the shaft body. There is a certain advantage, and the rotational movement of the mechanical component connected to the shaft body is allowed, or it can be preferably used for an application in which the rotational movement is actively used. For example, such a linear motion guide device can be used when a table plate on which an article to be inspected is placed is supported in such a manner that the observer can manually rotate freely and is movable up and down. In addition, for example, if a set of such linear motion guide devices is prepared and the shaft bodies of both of the linear motion guide devices are connected to the machine parts to be moved, this connection causes the shaft body of each linear motion guide device to Since the rotational movement in the circumferential direction is suppressed, the rotational movement is not particularly problematic.

DESCRIPTION OF SYMBOLS 10, 20 Linear motion bearing 11 Outer cylinder 11a Circumferential groove 11b Recessed part 12 Trunk part 13 Extension part 13a Base part of extension part 14 Opening 15 Spherical circulation groove 15a, 15b Linear groove 15c Connection groove 16 Cylindrical sphere holder 16b Convex part 17 , 17a Sphere 18 Shaft 18a Plane band 19 Annular stop 21 Arrow indicating the locus of the center of the moving sphere 17a 32 Body 32a End surface of body 32 33 Extension 36 Cylindrical sphere holder 60 Linear motion bearing 61 Outside Cylindrical 61a Circumferential groove 62 Body 65 Sphere circulation groove 65a Linear groove 66 Cylindrical sphere holder 66a Reinforcement part 67 Sphere 68 Shaft 68a Groove 69 Annular stopper 71 Arrow 77a indicating the locus of the center of the moving sphere 77a 77a sphere 78 Shaft body 78a Groove

Claims (5)

An outer cylinder and an elongated opening formed on the outer peripheral surface of a cylindrical body portion fitted inside the outer cylinder at intervals along the circumferential direction so that a sphere can partially protrude on the inner peripheral side A cylindrical sphere cage having a plurality of sphere circulation grooves, and a linear motion bearing comprising a plurality of spheres accommodated in each sphere circulation groove,
Circumferential grooves are formed at intervals on the inner peripheral surface of the outer cylinder, and extensions having an outer diameter smaller than the inner diameter of the outer cylinder are provided at both ends of the body of the cylindrical sphere retainer. An annular stopper is accommodated at the outer peripheral portion of each circumferential groove of the outer cylinder, and the inner peripheral portion of the base portion or the trunk portion of each extension portion of the cylindrical sphere cage is provided. A linear motion bearing characterized in that movement of the retainer in the length direction of the outer cylinder is prevented by being arranged in contact with each end face.   The linear motion bearing according to claim 1, wherein the annular stopper has a circular cross-sectional shape perpendicular to the circumferential direction.   The linear motion bearing according to claim 1, wherein the annular stopper has a C-shaped shape with a part thereof being discontinuous.   The linear motion bearing according to claim 1, wherein a surface of a base portion of each extension portion forms a curved surface.   The cylindrical sphere holder of the linear motion bearing according to any one of claims 1 to 4, wherein the shaft body is in contact with a sphere projecting inward from the opening of each sphere circulation groove of the holder. A linear motion guide device housed in

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