JP2010203466A - Linear motion guide device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a linear motion guide device capable of restraining the rotational movement in the peripheral direction of a shaft body, capable of increasing the effective ball number, and easy to miniaturize. <P>SOLUTION: This linear motion guide device 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 the 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, a plurality of spheres (17) stored in the respective sphere circulating grooves, and a columnar shaft body (18) stored in the cylindrical sphere cage in a state of contacting with the sphere of projecting from the opening of the cage. The linear motion guide device is characterized in that a plane band (18a) extending in the length direction of the shaft body is formed in a position corresponding to the opening of the cage of an outer peripheral surface of this columnar shaft body, and rotation in the peripheral direction of the shaft body is restrained by engagement between this plane band and the sphere of projecting from the opening of the cage. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a linear motion guide device that supports a shaft body so as to be slidable in the length direction thereof.

  The linear motion guide device supports a shaft body so as to be slidable in the length direction thereof, and is used to move machine parts of various industrial machines fixed to the shaft body.

  FIG. 15 is a partially cutaway perspective view showing a configuration of a conventional linear motion guide device.

  The linear motion guide device 60 of FIG. 15 is formed on the outer cylinder 61 and the outer peripheral surface of 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,... Each having an elongated opening capable of partially protruding the sphere (note that the opening is the bottom of the linear groove 65a of the sphere circulation groove 65). A plurality of spheres 67, 67,..., And cylindrical sphere holder 66 accommodated in each sphere circulation groove 65 from the opening of each sphere circulation groove 65 of the holder 66 to the inner peripheral side. It is composed of a cylindrical shaft body 68 accommodated in contact with the protruding sphere 67. A linear motion guide device having such a configuration is described in Patent Document 1, for example.

  As described above, the shaft body 68 of the linear motion guide device 60 is supported by the sphere 67 protruding from the opening of each sphere circulation groove 65 of the cylindrical sphere holder 66 to the inner peripheral side. 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. Hereinafter, such a linear motion guide device is referred to as an “infinite circulation type linear motion guide device”. The infinite circulation type linear motion guide device has a great advantage that the movable range of the shaft body is not limited.

  A plurality of grooves 68 a formed at positions corresponding to the openings of the spherical circulation grooves 65 of the cylindrical spherical body retainer 66 are provided on the outer peripheral surface of the shaft body 68. And the spherical body 67 which protrudes to the inner peripheral side from the opening of each spherical circulation groove 65 of the retainer 66 is accommodated in each groove 68a of the shaft body 68, so that the rotational movement of the shaft body 68 in the circumferential direction is suppressed. Has been.

  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.

  On the other hand, Patent Document 2 discloses a linear motion guide device including a cylindrical sphere holder that holds a plurality of spheres in a state where each sphere partially protrudes toward the inner peripheral surface side and the outer peripheral surface side. . A shaft body is accommodated in the cylindrical sphere holder, and the shaft body is supported by the sphere projecting toward the inner peripheral surface of the sphere holder as described above. When the shaft is moved in the length direction, the sphere supporting the shaft moves along with the sphere holder along the length of the outer cylinder. Therefore, the movable range of the shaft body of this linear motion guide device is limited to a range corresponding to the movable range inside the outer cylinder of the cylindrical spherical cage. Hereinafter, such a linear motion guide device is referred to as a “non-infinite circulation type linear motion guide device”.

  And in the same document, in the non-infinite circulation type linear motion guide device, the rotation of the shaft body in the circumferential direction is suppressed by forming a plane at a position where the spherical body contacts the outer peripheral surface of the shaft body. It is described.

JP 2004-28192 A (FIG. 19) Japanese Patent Laid-Open No. 2005-113938

In the linear motion guide device 60 of FIG. 15, if the length of the cylindrical sphere holder 66 is the same, the ratio of the length (L _G ) of the sphere circulation groove 65 to the length (L _R ) of the holder 66 ( (L _G / L _R ) increases, the number of spheres 67 that support both of the outer cylinder 61 and the shaft body 68 and support the shaft body 68 (hereinafter referred to as “effective ball number”) increases. Load resistance 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 guide device 60 decreases.

  However, for example, when the shaft body 68 of the linear motion guide device 66 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 motion guide device 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 of the reinforcing portion 66a ( Since L _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 guide device 60 or to further reduce the size of the linear motion guide device 60.

  An object of the present invention is to provide a linear motion guide device in which 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 easily reduced.

The present invention is formed on the outer surface of the outer cylinder and the cylindrical body part fitted inside the outer cylinder at intervals along the circumferential direction, and can partially project the sphere on the inner peripheral side. A cylindrical sphere holder having a plurality of sphere circulation grooves having a long and narrow opening, a plurality of spheres accommodated in each of the sphere circulation grooves, and an opening of each sphere circulation groove of the cage in the cylindrical sphere holder A linear motion guide device composed of a cylindrical shaft housed in contact with a sphere projecting to the inner circumference side,
A plane band extending in the length direction of the shaft body is formed at a position corresponding to the opening of each sphere circulation groove of the cylindrical sphere holder on the outer peripheral surface of the cylindrical shaft body. The linear motion guide device is characterized in that the rotation of the shaft body in the circumferential direction is suppressed by the engagement with the spherical body protruding from the opening of the circulation groove.

Preferred embodiments of the linear motion guide device of the present invention are as follows.
(1) Circumferential grooves are formed at intervals on the inner peripheral surface of the outer cylinder, and each of both ends of the body of the cylindrical sphere retainer has an outer diameter smaller than the inner diameter of the outer cylinder. An extension is provided, and an annular stopper is accommodated in each peripheral groove of the outer cylinder at its outer peripheral part, and the inner peripheral part is the base or cylinder of each extension part of the cylindrical spherical cage retainer By being arranged in contact with each end face of the part, the cage is prevented from moving in the length direction of the outer cylinder.
(2) The cross-sectional shape perpendicular to the circumferential direction of the annular stopper is circular.
(3) The annular stopper has a C-shaped shape with a part thereof being discontinuous.
(4) The surface of the base portion of each extension portion forms a curved surface.

  In the linear motion guide device of the present invention, the planar band provided on the outer peripheral surface of the shaft body engages with the sphere projecting from the opening of each spherical circulation groove of the cylindrical sphere cage to the inner peripheral side. The rotation in the circumferential direction is suppressed. In the linear motion guide device of the present invention, the sphere supporting the planar zone of the shaft can be immediately swung along the planar zone inside the spherical circulation groove of the cylindrical sphere holder. . Therefore, the linear motion guide device of the present invention is effective in supporting the shaft body when the length of the spherical circulation groove is set to be the same as the length of the spherical circulation groove of the conventional linear motion guide device. Since the number of balls can be increased, the load resistance can be improved. In addition, the linear motion guide device of the present invention has the same load resistance as that of the conventional linear motion guide device (to ensure the same number of effective balls), the spherical circulation groove of the cylindrical spherical body cage Since the length can be shortened, the size can be reduced (the length of the outer cylinder that accommodates the cylindrical sphere holder is shortened).

It is a figure which shows the structural example of the linear motion guide apparatus of this invention. It is sectional drawing of the linear guide apparatus 10 cut | disconnected along the cutting line II-II line entered in FIG. It is sectional drawing of the linear guide apparatus 10 cut | disconnected along the cutting line III-III line entered in FIG. It is sectional drawing of the linear guide apparatus 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 guide apparatus of this invention. It is a partially notched perspective view which shows the structure of the conventional linear motion guide apparatus.

  A linear motion guide device of the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a diagram illustrating a configuration example of the linear motion guide device of the present invention. FIG. 2 is a cross-sectional view of the linear guide device 10 cut along the cutting line II-II entered in FIG. FIG. 3 is a sectional view of the linear motion guide device 10 cut along the cutting line III-III entered in FIG. 4 is a cross-sectional view of the linear motion guide device 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.

  A linear motion guide device 10 shown in FIGS. 1 to 7 is formed on an outer cylinder 11 and an outer peripheral surface of a cylindrical body 12 fitted inside 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 spheres on the inner peripheral side, are accommodated in the sphere circulation grooves 15. A cylindrical shaft body accommodated in a plurality of spheres 17, 17, and, and a cylindrical sphere holder 16 in contact with the spheres 17 protruding from the openings 14 of the sphere circulation grooves 15 of the holder 16 to the inner peripheral side. 18 or the like. The linear motion guide device 10 extends in the longitudinal direction of the shaft 18 at a position corresponding to the opening 14 of each spherical circulation groove 15 of the cylindrical sphere holder 16 on the outer peripheral surface of the cylindrical shaft 18. Mainly, the planar band 18a is formed, and the rotation of the shaft 18 in the circumferential direction is suppressed by the engagement of the planar band 18a and the sphere 17 protruding from the opening 14 of each sphere circulation groove 15. 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.

  When the shaft 18 of the linear guide device 10 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 sandwiched between the outer cylinder 11 and the shaft 18. It rolls in a state where it is turned and circulates and moves 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.

  Next, the planar band 18a formed on the outer peripheral surface of the shaft body 18 of the linear guide apparatus 10 will be described.

  As described above, the planar band 18a extending in the length direction of the shaft 18 is located at a position corresponding to the opening 14 of each spherical circulation groove 15 of the cylindrical sphere holder 16 on the outer peripheral surface of the cylindrical shaft 18. Is formed. Since the linear guide apparatus 10 of the present invention includes such a planar band 18a, the following effects are exhibited.

  First, as described above, the shaft body 18 is provided with the plane band 18a, and the rotation of the shaft body 18 in the circumferential direction is caused by the engagement between the plane band 18a and the sphere 17 protruding from the opening 14 of the sphere circulation groove 15. It is suppressed.

  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. Thus, the effect that the planar band 18a of the shaft body 18 suppresses the rotation of the shaft body in the circumferential direction is the plane provided on the shaft body of the (non-infinite circulation type) linear motion guide device of the above-mentioned Patent Document 2. Is similar to the effect exhibited by.

  The present invention is greatly characterized in that the planar band 18a as described above is provided in the shaft body 18 of the infinite circulation type linear motion guide device 10. Thereby, in addition to the effect which suppresses the rotation to the circumferential direction of the shaft 18 as mentioned above, the linear motion guide apparatus 10 of this invention exhibits the extraneous effect which cannot be further predicted from the invention of patent document 2. . The effect peculiar to the linear motion guide device 10 of the present invention will be described with reference to FIGS.

  FIG. 8 is a diagram showing a path along which the sphere 17a shown in the drawing moves in the sphere circulation groove 15 in the linear guide apparatus 10 of the present invention shown in 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 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 apparatus having a groove in the shaft. 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 the infinite circulation type linear motion guide device moves in the sphere circulation groove of the cylindrical sphere holder will be described. For example, in the linear motion guide device 10 of the present invention, the sphere supporting the shaft body, that is, the sphere housed in the linear groove 15a of the cylindrical sphere holder 16 of FIG. 6 is moved by the movement of the shaft body. When moving (rolling) to one end of the linear groove 15a, the linear groove 15a 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 device (for example, the conventional infinite circulation type linear motion guide device shown in FIG. 15) having a groove in the shaft.

However, as shown in FIGS. 11 to 13, in the conventional linear motion guide device having the shaft 78 having the groove 78 a, in order to turn the sphere 77 a, first, the sphere 77 a is inserted into the groove 78 a of the shaft 78. After moving to the outside, 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, at a distance ΔH corresponding to the depth of the groove 78a. It is necessary to turn this 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 in which the shaft body 18 includes the planar band 18 a, it is not necessary to move the spherical body 17 a to the outside of the groove before the turning movement. Can be swiveled 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.

  Therefore, if the linear motion guide device 10 of the present invention exhibits the load resistance equivalent to that of the conventional linear motion guide device (to ensure the same number of effective balls), the length of the spherical circulation groove 15 is Since it can be shortened by a length twice as long as the distance ΔL shown in FIGS. 12 and 13, it can be reduced in size (the length of the outer cylinder 11 that accommodates the cylindrical sphere holder 16 having the sphere circulation groove 15 described above) Can be shortened).

  Further, the linear motion guide device 10 of the present invention supports the shaft body 18 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. Since the number of effective balls can be increased, the load resistance can be improved.

  Thus, the linear motion guide device of the present invention is capable of suppressing the rotational movement of the shaft body in the circumferential direction, can increase the number of effective balls, and can be easily downsized.

  In the linear motion guide device of the present invention, circumferential grooves are formed on the inner peripheral surface of the outer cylinder at intervals, and the inner diameter of the outer cylinder is provided at each of both ends of the barrel portion of the cylindrical sphere holder. An extension having a smaller outer diameter is provided, and an annular stopper is accommodated in each peripheral groove of the outer cylinder at its outer peripheral part, and the inner peripheral part of the barrel part of the cylindrical sphere retainer It is preferable that movement of the retainer in the length direction of the outer cylinder is prevented by being arranged in contact with each end face of the base part or the body part of each extension part.

  As shown in FIG. 1 to FIG. 7, in the linear motion guide device 10, circumferential grooves 11 a and 11 a are formed on the inner peripheral 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 further increase the load resistance of the linear motion guide device 10 by increasing the number of effective balls that support the shaft 18, or to further reduce the size of the linear motion guide device 10.

  As described above, in the conventional linear motion guide device 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 not deformed by the force applied from the sphere 67. It is necessary to provide reinforcing portions 66a and 66a on both outer sides of the spherical circulation groove 65 of the cage 66.

  On the other hand, in the linear motion guide device 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 guide device 10 of the present invention, the sphere circulation groove 15 having a longer length than the conventional linear motion guide device is formed between the extensions 13 and 13 of the cylindrical sphere holder 16. Can be formed. Note that the spherical circulation groove may be formed to extend to the outer peripheral surface of each extension portion 13.

  Accordingly, the linear guide device 10 of the present invention reinforces the cylindrical sphere cage 16 so as to exhibit the same load resistance as the conventional linear guide device (to ensure the same number of effective balls). Each extending portion 13 can be accommodated and arranged at a position on the inner peripheral side of each annular stopper 19 that supports and fixes the cage 16, so that it can be produced in a smaller size.

  Moreover, if the linear guide apparatus 10 of this invention uses the outer cylinder of the same length as the outer cylinder of the conventional linear guide apparatus, the cylindrical sphere holding | maintening a longer length will be hold | maintained inside this outer cylinder. Since the number of effective balls can be increased by accommodating and fixing a container, that is, a cylindrical sphere holder having a longer sphere circulation groove, 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 guide device 10 according to the present invention described with reference to FIGS. 1 to 7 has an effective number of balls (the number of spheres protruding from the openings 14 of the sphere circulation grooves 15 and supporting the shafts 18). For example, when three are set, 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 infinite circulation type linear motion guide device.

  FIG. 14 is a cross-sectional view showing another configuration example of the linear motion guide device of the present invention. In the configuration of the linear guide device 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 trunk portion 32 where the extension portion 33 is provided. Except for being prevented by the annular stopper 19, it is the same as the linear guide device 10 shown in FIGS. 1 to 7.

  As described above, in the linear motion guide device 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 described above). It is particularly preferable to prevent it by placing an annular stopper in contact with the base of the part or the end face of the body part.

DESCRIPTION OF SYMBOLS 10, 20 Linear motion guide apparatus 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 Spherical body 18 Shaft body 18a Plane band 19 Annular stopper 21 Arrow indicating the locus of the center of the moving sphere 17a 32 Body 32a End face of body 32 33 Extension 36 Cylindrical sphere holder 60 Linear motion guide device 61 Outer cylinder 61a Circumferential groove 62 Body 65 Sphere circulation groove 65a Linear groove 66 Cylindrical sphere holder 66a Reinforcement part 67 Sphere 68 Axis 68a Groove 69 Annular stopper 71 An arrow 77a indicating the locus of the center of the moving sphere 77a Sphere 78 Shaft 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 holder having a plurality of sphere circulation grooves having a plurality of spheres accommodated in each sphere circulation groove, and a cylindrical sphere holder from the opening of each sphere circulation groove of the holder to the inner peripheral side A linear motion guide device comprising a cylindrical shaft housed in contact with a protruding sphere,
A plane band extending in the length direction of the shaft body is formed at a position corresponding to the opening of each sphere circulation groove of the cylindrical sphere holder on the outer peripheral surface of the cylindrical shaft body. A linear motion guide device characterized in that rotation of a shaft body in a circumferential direction is suppressed by engagement with a sphere protruding from an opening of a sphere circulation groove.   Circumferential grooves are formed at intervals on the inner peripheral surface of the outer cylinder, and extension portions having an outer diameter smaller than the inner diameter of the outer cylinder are provided at both ends of the cylindrical sphere cage. An annular stopper is accommodated in each peripheral groove of the outer cylinder at its outer peripheral part, and the inner peripheral part is each of the base part or the trunk part of each extension part of the cylindrical sphere cage body. The linear motion guide device according to claim 1, wherein movement of the retainer in the length direction of the outer cylinder is prevented by being arranged in contact with the end face.   The linear motion guide device according to claim 2, wherein a shape of a cross section of the annular stopper perpendicular to the circumferential direction is a circle.   The linear motion guide device according to claim 2, wherein the annular stopper has a C-shape that is partially discontinuous.   The linear motion guide device according to claim 2, wherein a surface of a base portion of each extension portion forms a curved surface.

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