JP2002349563A - Linear motion bearing and manufacturing method for roller retaining belt used for this - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a movement resistance of a relative movement part and lengthen a relative movement distance in a linear motion bearing in which a shaft 1 is penetrated through a tube 2 such that it is relatively moved linearly in the state that it maintains a constant attitude. SOLUTION: A guide surface becoming a bottom part of a groove 20 axially formed on an inner periphery surface of the tube 2 is made opposed to an outer periphery surface of the shaft 1 and rollers 31 having an axis in a widthwise direction of the recessed groove are interposed on the opposed surface in a preload state. A return passage of the roller is penetrated and formed on a body part of the tube 2 on the back surface side of the guide surface and bent passages 40 for guiding the roller from a space between the guide surface and the outer periphery surface part to the return passage are provided at both ends of the tube. Roller installing apertures 38, 38 for rotatably installing rollers 31, 31 on a roller retaining belt 39 circulating and traveling along a circulation passage connecting these bent passages 40, 40 at both ends are formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear motion bearing in which a shaft passes through a cylinder in a linearly moving state via a rolling movement mechanism.

[0002]

2. Description of the Related Art As this type of linear motion bearing, a type in which a ball is held by a cylindrical retainer (Japanese Patent Publication No. 62-48089) has been proposed. Is a point contact, there is a problem of durability in a linear motion bearing that repeats linear movement. Further, since the wear resistance of the ball and the point contact portion is insufficient, the resistance of the rolling moving portion cannot be maintained at a low value for a long period of time. Furthermore, since the cylindrical retainer is only interposed between the shaft and the cylinder that perform relative reciprocating movement in the axial direction,
There is also a problem that the reciprocation of the relative reciprocation between the shaft and the cylinder may cause the shaft to gradually deviate from the proper position in the axial direction.

[0003] To solve this problem, Japanese Utility Model Application
No. 137524 discloses a linear motion bearing of a type in which a plurality of rollers, both ends of which are rotatably supported in a recess formed in a side wall of a shaft, are in rolling contact with a flat portion of a cylindrical portion. I have. In this device, since both ends of the roller are pivotally supported in the concave portion, a retainer such as the ball type is unnecessary, but the roller is interposed between the shaft and the cylinder in a rolling movement state. However, there is a problem that the movement resistance between the two cannot be sufficiently reduced. This is because a concentrated load acts on the shaft support portion and the rotational resistance of the roller increases. Further, since the roller is supported on the shaft, there is a problem that the moving distance of the cylinder having a predetermined length with respect to the shaft cannot be increased. This is because the cylinder and the shaft cannot move relative to each other under the condition that the roller disposition portion is out of the cylinder.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has been made in consideration of the above-mentioned problem. "A linear motion bearing penetrates so that a shaft moves linearly relative to a cylinder while maintaining a constant posture. It is an object of the present invention to reduce the moving resistance of the relative moving unit and increase the relative moving distance.

[0005]

Means for Solving the Problems [1] The technical means of the present invention for solving the above-mentioned problem is that a plurality of concave grooves parallel to the axis are formed on the inner peripheral surface of the cylinder. A guide surface serving as the bottom of the groove faces the outer peripheral surface of the shaft, and a roller having a widthwise axis of the groove is interposed between the guide surface and the outer peripheral surface in a pre-pressed state, A return passage serving as a return movement path of the roller is formed through the body of the cylinder on the rear side of the guide surface, and the roller is provided at both ends of the cylinder from between the guide surface and the outer peripheral surface. A bent passage for guiding the return passage is provided, and one of the bent passages passes between the guide surface and the outer peripheral surface portion to return from the other bent passage to the one bent passage via the return passage. Circulating along the circulating passage A roller holding belt is provided, and each of a plurality of roller loading holes that penetrates the constituent walls of the roller holding belt from front to back and is arranged in parallel at intervals in the longitudinal direction of the roller holding belt. The roller is rotatably mounted so that the outer periphery protrudes from both openings of the hole, and the roller holding belt has a configuration in which the wall thickness of the component wall between the adjacent roller mounting holes is such that the roller mounting hole is formed. Section is thinner than the wall thickness.]

The above technical means operates as follows. When the shaft and the cylinder moved relative to each other in the axial direction, the shaft and the cylinder were rotatably loaded in a roller loading hole interposed between the outer peripheral surface of the shaft and the guide surface of the cylinder and penetrating through the roller holding belt. Rollers roll between the said. That is, the rollers travel in the axial direction between the rollers together with the roller holding belt that holds the rollers. At this time, the roller at the end on the side where the shaft is extended from the cylinder is guided to the return path side via the bent passage at this end of the cylinder, and the roller in the return path is opposite to the extension direction. Move in the direction of. The roller is supplied from the return passage to a portion between the outer peripheral surface of the shaft and the guide surface of the cylinder on the bending passage side at the other end.

In this way, the roller, together with the roller holding belt holding the roller, "between the guide surface and the outer peripheral surface portion", "one bent passage", "return passage", "the other bent passage", "guide". Between the surface and the outer peripheral surface ". Therefore, since a roller is always interposed between the guide surface and the outer peripheral surface portion, the roller can move linearly with respect to a cylinder having a predetermined length even if the shaft length is infinite. Moreover,
Since the roller interposed in the pressurized state between the outer peripheral surface of the shaft and the guide surface of the cylinder is always in rolling contact, and no sliding contact portion is generated in the relative moving portion between the outer peripheral surface and the guide surface, the shaft Movement resistance can be reduced.

In addition, since the rollers are separately loaded into the roller loading holes of the roller holding belt and are held in a state where they do not contact each other, the rollers move synchronously without contacting each other, and all the rollers move. The roller moves smoothly in the above-mentioned circulation path. That is, by holding all the rollers on the roller holding belt, there is no inconvenience such that the rollers meander even in a place where the rollers are not pressurized, such as in a bent passage or a return passage, and the roller is jammed.

Further, according to the above technical means, since the constituent wall of the roller holding belt between the adjacent roller loading holes is formed thin, the roller holding belt is bent and deformed at the thin portion. It will be easier. This makes it easier for the roller holding belt having the rollers to smoothly travel along the curved path.

[2] The method according to [1], wherein, of the component walls between the roller loading holes adjacent to each other, an outer surface facing the outside of the circulation passage is a portion where the roller loading holes are formed. Formed flush with the outer surface.

[0011] With this configuration, the thin portion between the roller loading holes in the roller holding belt passes through the outer peripheral region of the minimum curvature of the bending path, so that the degree of curvature of the thin portion during the passage is reduced. Can be suppressed. Therefore, compared to the case where the degree of curvature is large (the case where the thin portion passes through the inner peripheral region of the bent passage), even if the thin portion is repeatedly deformed each time the bent passage is passed, The thin portion is less susceptible to tissue fatigue, and its durability is improved.

[3] In the above item [1] or [2], wherein the "roller holding belt is made of a bendable and deformable synthetic resin mixed with reinforcing fibers", The strength of the holding belt is improved.

[4] In any one of the above items [1] to [3], "the reinforcing wire continuous in the longitudinal direction of the roller holding belt is embedded in the constituting wall of the roller holding belt." The reinforcing wire increases the tensile strength of the roller holding belt in the running direction, thereby further improving the strength of the roller holding belt.

[5] In the item [1] to [4], in the case where the roller holding belt is formed in an endless ring shape bent along the circulation path, the roller holding belt is formed along the circulation path. As compared with the case where a loaded belt-shaped roller holding belt with both ends non-coupled is employed, the roller holding belt can more easily run along the circulation path together with the rollers provided therein.

[6] The method according to the above [1], wherein the roller holding belt is formed of a thin metal plate, and the roller loading hole is
An opening formed by punching the thin metal plate and a pair of protruding plate portions cut and raised in the same direction from an opposing portion of a peripheral edge of the opening and rotatably holding the body of the roller. " Is pressed to form the opening, and at the same time, a protruding plate portion is cut and raised at a peripheral portion thereof, and the protruding plate portion is bent into a predetermined shape to form a roller holding belt. That is, according to the sixth aspect, since the roller holding belt can be manufactured from one sheet metal sheet, the manufacturing of the roller holding belt can be easily performed as compared with the case of resin molding.

[7] The method for manufacturing the roller holding belt constituting the linear motion bearing according to the above [1] to [5] includes a method of forming a cylindrical forming die having a forming unevenness on an outer peripheral surface thereof; A rotary molding machine consisting of an auxiliary cylindrical mold parallel to the mold,
Using an extruder that continuously extrudes the plasticized resin, the plasticized resin continuously extruded from the extruder is passed through the gap between the rotating cylindrical molding die and the auxiliary cylindrical mold, Manufacturing the roller holding belt by cutting the continuous belt-shaped body having passed through the gap into appropriate lengths ".

In this apparatus, when a plasticized resin continuously extruded from an extrusion molding machine is rotated while pressing both the molds between a cylindrical molding die and an auxiliary cylindrical die, a length in which a roller loading hole and the like are formed is formed. When a long roller holding belt is obtained, and the long roller holding belt is cut into appropriate lengths, the roller holding belt constituting the linear motion bearing described in the above items 1 to 4 is completed.

[0018]

The present invention has the following specific effects. The relative movement length between the shaft and the cylinder can be set long. For example, even if the shaft is infinitely long, it can be linearly moved with respect to a cylinder of a predetermined length. Also, since there is no sliding contact between the outer peripheral surface of the shaft and the relative moving portion of the guide surface of the cylinder,
Moving resistance can be reduced. Furthermore, since each roller is individually loaded into a roller loading hole formed in the roller holding belt, the rollers move synchronously without contacting each other. Therefore, all the rollers move smoothly in the circulation passage, and a smooth relative movement between the shaft and the cylinder can be ensured.

Further, as described above, since the roller holding belt easily runs smoothly along the bending path, the operation of the linear motion bearing is further smoothed. Further, since the roller and the roller holding belt holding the roller are loaded in the circulation passage formed in the constituent wall of the cylinder, even if the operation of reciprocating the cylinder and the shaft relatively in the axial direction is repeated, There is no inconvenience such that the roller holding belt or the like is shifted from the loading portion in the axial direction.

The following problem arises when the wall of the roller holding belt between the roller mounting holes is formed thick and the wall of the roller mounting hole is thin. That is, in the portion where the roller holding belt is curved along the bending path, the roller loading hole is deformed so as to contract in diameter. Therefore, the outer periphery of the roller is pressed by the inner peripheral surface of the roller loading hole, and smooth rotation is hindered. On the other hand, in the present invention, since the constituent walls of the roller holding belt between the adjacent roller loading holes are formed to be thin, there is no concern that the smooth rotation of the rollers located in the bent passage portion is hindered.

According to the second aspect, the thin portion between the roller loading holes in the roller holding belt is less susceptible to tissue fatigue, and the durability is improved.

In the items 3 and 4, the strength of the roller holding belt can be improved.

In the item (6), since the roller holding belt is formed from one sheet metal sheet, the roller holding belt can be easily manufactured.

According to the seventh aspect, it is possible to provide a belt manufacturing method suitable for manufacturing a roller holding belt constituting the linear motion bearing according to the first to fifth aspects.

[0025]

Next, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a side view of a partially cut-away portion of a linear motion bearing according to an embodiment of the present invention. As shown in the drawing, the linear motion bearing includes a shaft (1) and a shaft (1). And a plurality of rollers (31) interposed therebetween. In this embodiment, for example,
The shaft (1) is a guide shaft that stands upright on a fixed bed, and a tube (2) that moves up and down a predetermined stroke is externally fitted to the guide shaft, and the tube (2) is attached to a lifting table (T). It is something that can be done.

The shaft (1) is formed in a hexagonal column shape, and the cylinder (2) has an inner peripheral surface formed along the outer peripheral surface portion (11) of the shaft (1) ( (See FIG. 2). A concave groove (20) is formed in each of the six band-shaped flat portions (29) parallel to the axis formed on the inner periphery of the cylinder (2), and the concave groove (20) is formed.
The bottom of the roller (31) is a guide surface (21) which is a running surface of the roller (31), and this guide surface (21) is a smooth surface on the shaft side of the outer periphery of the shaft (1).
(19) and these guide surfaces (21)
A roller (31) is interposed between the shaft and the smooth surface (19) in a pressurized state. Further, the belt guide grooves (200) (20) into which both side edges of the roller holding belt (39) enter are provided on both side walls of the concave groove (20).
0) is formed.

A return passage (22) serving as a return movement path for the roller (31) is formed in the body of the cylinder (2) behind the guide surface (21) so as to extend in the axial direction. . A bent passage (40) for guiding the roller (31) from between the guide surface (21) and the shaft-side smooth surface (19) to the return passage (22) is provided at both ends of the cylinder (2). Is provided.

As shown in the enlarged view of FIG. 3, the roller (31) is provided between the guide surface (21) and the shaft-side smooth surface (19), the bent passage (40) and the return passage (22). ) Are filled in a horizontal position, and the rollers (31) are held by a roller holding belt (39) made of an elastic synthetic resin into which reinforcing fibers are mixed. 4 and 5
As shown in the figure, the roller holding belt (39) has a large number of roller loading holes arranged in parallel at intervals in its longitudinal direction.
(38) is penetrated, and a cylindrical roller (31) is rotatably loaded in the roller loading hole (38). And
The roller holding belt (39) is located between the roller loading holes adjacent to each other.
(38) The wall thickness of the component wall between (38) and (37) is the roller loading hole (3
8) is thinner than the thickness of the formation portion (36). Further, the roller holding belt (39) has an outer surface (35) between the mutual (37) and an outer surface (an outer surface of the circulation passage) of the forming portion (36) of the roller loading hole (38) flush. While being formed, the corrugated uneven portions (33) (33) formed at both longitudinal ends of the roller holding belt (39) are engaged with each other so as to mesh with each other, and are assembled into a ring as a whole. Further, the diameter of the roller (31) is set to be slightly larger than the thickness of the formation portion (36) of the roller loading hole (38), and as a result, as shown by the imaginary line in FIG. The outer periphery of the roller (31) loaded on the roller (38) projects slightly from the front and back of the roller holding belt (39). Further, a concave groove located between the roller loading holes (38) and (38) and extending in the width direction of the roller holding belt (39).
(28) is formed, thereby forming a roller loading hole (38).
Elastic tongues (27) (27) that can be elastically deformed in the direction of coming into contact with and separating from the side surface of the roller (31) are formed on both sides in the width direction. Therefore, when the roller (31) is forcibly pressed into the roller loading hole (38) from between the tips of the pair of elastic tongues (27), (27), the tip of the elastic tongues (27), (27) The distance between
This allows the roller (31) to enter the roller loading hole (38). By doing so, each roller loading hole (38)
Rollers (31) and (31) are separately loaded into (38) in a rotatable and fall-prevention state. Next, a method of manufacturing the roller holding belt (39) will be described with reference to FIGS.

On the downstream side of an extruder (81) for continuously extruding an elastic resin (82) as a plasticizing resin containing reinforcing fibers,
A rotary forming machine comprising a cylindrical forming die (83) and an auxiliary cylindrical die (84) parallel thereto, and a molded product peeling guide (85) having an arc-shaped cross section located on the outlet side of the rotary forming machine are provided. FIG.
As shown in the figure, on the outer periphery of one cylindrical forming die (83), forming irregularities (86) corresponding to the cross section of the roller holding belt (39) are formed, and the other auxiliary cylindrical die (84) is formed. ) Has a simple cylindrical outer peripheral surface. Therefore, when the elastic resin (82) in a semi-cured state continuously extruded from the extruder (81) passes between the cylindrical molding die (83) rotating at a low speed and the auxiliary cylindrical die (84), the above-described molding is performed. The elastic resin (82) is squeezed and deformed by the unevenness (86) for use and the auxiliary cylindrical type (84), and the roller holding belt (3
It is formed into the same cross-sectional shape as in 9). Then, while the elastic resin (82) molded into this cross-sectional shape escapes at a low speed between the cylindrical molding die (83) and the auxiliary cylindrical die (84), it is further cured, and the cured elastic resin (82) ) Is guided by the molded product peeling guide (85) to change the course, whereby the elastic resin (82) is peeled from the molding irregularities (86) on the outer periphery of the cylindrical molding die (83). As a result, a long strip-shaped intermediate product having the same cross-sectional shape as that of the roller holding belt (39) is obtained. When this intermediate product is cut into appropriate lengths by a wavy cutter having a continuous arc, the wavy uneven portions are formed at both ends. (33) The roller holding belt (39) having (33) as shown in FIG. 4 is completed.

On the other hand, as described above, the cylinder (2) for filling the roller (31) is provided with a concave groove (20) on the inner peripheral surface thereof (see FIG. 2) and has the same structure. A hole (30) is formed in the wall as the return passage (22) extending in the axial direction. The concave groove (20) has a depth equal to that of the roller (3).
The diameter substantially coincides with the diameter of 1), and the bottom portion serves as a guide surface (21) of the roller (31).

As shown in FIGS. 2 and 11, the hole (30)
The width of the return passage (22) (the width in the diameter direction of the roller (31)) is set to be larger than the diameter of the roller (31), so that the outer circumference of the roller (31) is )
So that it does not come into contact with the inner wall (220). Therefore,
The roller (31) passing through the return passage (22) is
No noise is generated by contacting the inner wall of 2). Belt guide grooves (25) and (25) are provided on both side walls of the return passage (22) so as to face each other, and the inside of the belt guide grooves (25) and (25) runs on both sides of the roller holding belt (39). The edge runs.

The return passage (2) in the hole (30)
A groove (23) is formed on the wall surface on the side of the concave groove (20) of 2), and the groove (23) has a felt (24) impregnated with a lubricant.
Is loaded. Also, a ridge is provided on the groove bottom of the groove (23).
(26) is protruding, which allows the
The central portion in the width direction of (24) comes into contact with the roller (31) to apply a lubricant thereto. This allows the guide surface
Seizure of the roller (31) between the shaft (1) and the shaft (1) can be reliably prevented, and the durability of the linear motion bearing is improved. In the present embodiment, the groove (23) is formed inside the return passage (22) (on the side of the concave groove (20)). Conversely, the groove (23) is formed.
May be formed outside the return passage (22).

Both ends in the longitudinal direction of the hole (30) and the concave groove (20) are open to the end face of the cylinder (2) (see FIGS. 2 and 3). An annular lid (50) as shown in FIG. 6 is attached. The lid (50) is formed with an outer guide (5) for moving the roller (31) in the radial direction at the end face of the cylinder (2).

The outer guide (5) has an inner peripheral curved surface (51) serving as an outer peripheral surface of a curved passage (40) as a moving path of the roller (31).
Are formed at positions where the circumference is divided into six equal parts in accordance with the six concave grooves (20). Further, the end face of the tube (2) and the
An inner guide (4) is interposed between the two inner peripheral curved surfaces (51) as shown in FIGS.

As shown in FIGS. 7 (a) and 7 (b), the inner guide (4) is a semi-cylindrical body having an outer peripheral curved surface (41) which is an inner surface of the bent passage (40), and 2), the entire size of which is larger than the roller (31), and the groove (23) and the guide surface (2) except for the return passage (22).
The size is set to close the end face up to 1) (Fig. 3
reference). Then, in such a position, the tongue piece (42) that fits into the groove (23) communicating with the return passage (22) protrudes from the back surface opposite to the outer curved surface (41) of the inner guide (4). Is formed.

On the other hand, semicircular pressing grooves (52) circumscribing the outer peripheral curved surface (41) of the inner guide (4) are provided at both ends of the inner peripheral curved surface (51) of the outer guide (5). (53). Accordingly, when the tongue piece (42) is fitted into the groove (23) and the lid (50) is further attached, the holding groove (52) is
(4) is closely fitted to the outer peripheral curved surface (41), whereby the inner guide (4) is positioned and fixed.

Next, the operation of assembling the linear motion bearing will be described. When assembling, first, the roller holding belt (3
The rollers (31) and (31) are loaded into the roller loading holes (38) and (38) of (9), and the lid (50) is attached to only one end of the cylinder (2). Next, the roller holding belt (39) whose front and rear ends are not connected is inserted into the groove (20) from the end of the cylinder (2) where the lid (50) is not attached. . And
Insert the leading end of the roller holding belt (39) into the insertion passage through the bent passage (40) located between the lid (50) and the inner guide (4) located at the end opposite to the insertion side. The hole (30) through the part (30)
Push in to the end on the insertion side in the above. And the groove
In (20), the tip of the roller holding belt (39) is exposed from the end where the lid (50) is not attached, and the wavy irregularities (33) (33) at the exposed tip are removed. They are joined so as to engage with each other. Next, another lid (50) is screwed to the end of the cylinder (2) where the lid (50) is not attached, and the shaft (1) is inserted into the cylinder (2). Insert it. Then, a roller holding belt (39) having roller loading holes (38) (38)
However, one bent passage (40) → between the guide surface (21) and the outer peripheral surface portion (11) of the shaft (1) → the other bent passage (40) → return passage (2
2) → A state in which the vehicle can be circulated along a circulation path connected in the order of the one bent path (40), and the rollers (31) and (31) loaded on the roller holding belt (39) are connected to the shaft (1). ) And the guide surface (21) of the cylinder (2) are in a state interposed in a pressurized state.

At the end of the cylinder (2), the outer curved surface of the inner guide (4)
(41) and the inner peripheral curved surface (51) of the outer guide (5) are located concentrically to form a semicircular bent passage (40) (see FIG. 3). ) On the shaft (1) side is the outer peripheral surface (1).
Since it is open in a form that almost contacts 1), the shaft (1)
Roller from the passage between the outer peripheral surface (11) and the guide surface (21).
(31) is smoothly introduced into the curved passage (40), while the curved passage
It moves smoothly from (40) to the passage.

Further, since the rollers (31) are separately loaded into the roller loading holes (38) and (38) of the roller holding belt (39), the rollers (31) are synchronized without contacting each other. Move. Thereby, the roller (31) group filled in the passage between the outer peripheral surface portion (11) and the guide surface (21) due to the relative movement between the shaft (1) and the cylinder (2) moves the bent passage (40). And return passage
It circulates through (22). Therefore, the shaft (1) can move linearly with respect to the cylinder (2). In addition, the return passage (22) is
Since the lubricant impregnated in the felt (24) is applied to the roller (31) during the movement of the roller (31), the roller (31) between the guide surface (21) and the outer peripheral surface (11) is moved. Can reliably be prevented, and the durability of the linear motion bearing is improved.

[Others] In the above embodiment, a simple columnar roller (31) is employed. However, as shown in FIG. 8, a columnar roller (31) having a central outer periphery narrower than both ends is employed. axis
The present invention can also be applied to a linear motion bearing having (1). Roller (3
The outer peripheral curved surface (310) of the central portion of (1) has a shape conforming to the outer peripheral surface of the columnar shaft (1), whereby the roller (31) is located on the outer peripheral surface of the shaft (1). This is because line contact is made along a certain length range in the circumferential direction.

[0041] In the above embodiment, the inner guide (4) is provided inside the lid (50) covering the end of the cylindrical body (2), but the inner guide (4) is not necessarily provided. Roller (31)
Because (31) is held by the endless ring-shaped roller holding belt (39), the rollers (31) and (31) surely move along the inner surface of the lid (50).

[0042] In the above embodiment, the roller holding belt (39) is formed of a synthetic resin material mixed with reinforcing fibers, but as shown by the imaginary line in FIG. 4, the reinforcing wires (61) (61) ( 61) The roller holding belt
It may be buried along both side edges of (39) to improve the strength. In this case, it is not always necessary to mix reinforcing fibers into the roller holding belt (39).

. In the above embodiment, the roller holding belt (39) is formed of a synthetic resin material, but as shown in FIG. 12, a thin metal plate such as phosphor bronze is pressed out to open the openings (71) (71).
And the protruding plate portions (72) (72) may be cut and raised in the same direction from a pair of long sides, which are peripheral edges of the openings (71) facing the openings (71). Then, the protruding plate portions (72) and (72) are curved so as to be convex in directions away from each other,
(72) The body of the roller (31) is rotatably held by (72).
The roller holding belt (39) has the protruding plate portions (72) (72)
Grease reservoirs (73) and (73) that are convex in the projecting direction of the metal roller holding belt (39) and the roller (3),
The mutual seizure due to sliding of the cylinder (2) or the shaft (1) is prevented.

A roller holding belt (3) made of a thin metal plate
The image sticking may be prevented by resin-coating the entire surface of 9). Further, a pair of long sides of the openings (71) and (71) are formed in a waveform, thereby forming the openings (71) and (71).
The long sides of the rollers (31) (31) may partially contact the surfaces of the rollers (31) (31) to reduce the rotational friction resistance of the rollers (31) (31).

[0045] As shown by the imaginary line in FIG. 3, the outer peripheral edge of the outer surface of the lid (50) covering the end of the cylinder (2) is curved outward in the axial direction of the shaft (1) to form an annular lip (58). This may prevent dust and the like from entering the cylinder (2) from the outside.

[Brief description of the drawings]

FIG. 1 is a side view of a partially cut-away portion of a linear motion bearing according to an embodiment of the present invention.

FIG. 2 is a plan view of a partially cut-out portion of the linear motion bearing of FIG. 1;

FIG. 3 is a sectional view taken along line YY of FIG. 2;

FIG. 4 is a plan view omitting an intermediate portion of the roller holding belt (39).

FIG. 5 is a sectional view of a roller holding belt (39).

FIG. 6 is a cross-sectional view of the lid (50).

FIG. 7 is an explanatory view of the inner guide (4).

FIG. 8 shows another embodiment.

FIG. 9 is a side view illustrating a manufacturing process of the roller holding belt (39).

FIG. 10 is a structural explanatory view of a cylindrical mold (83) and an auxiliary cylindrical mold (84).

FIG. 11 is an enlarged sectional view of a loading portion of a roller (31) in a cylinder (2).

FIG. 12 is a partially cutaway perspective view showing a modification of the roller holding belt (39).

[Explanation of symbols]

 (1) ・ ・ ・ Shaft (2) ・ ・ ・ Cylinder (4) ・ ・ ・ Inner guide (5) ・ ・ ・ Outer guide (20) ・ ・ ・ Groove (21) ・ ・ ・ Guide surface (22) ・..Return passage (31) ・ ・ ・ Roller (38) ・ ・ ・ Roller loading hole (39) ・ ・ ・ Roller holding belt

 ────────────────────────────────────────────────── ─── Continued on front page F term (reference) 3J101 AA13 AA24 AA32 AA42 AA52 AA64 AA71 BA36 BA44 BA47 BA50 BA53 BA54 BA55 BA64 DA09 DA14 EA13 EA31 EA76 FA04 FA15 FA31 FA41 FA44 GA60 3J104 AA03 AA25 AA27 AA67 AA63 BA13 BA14 BA16 BA24 BA33 BA64 CA05 CA13 CA35 DA06 DA20 4F213 AC03 AG17 AH12 WA04 WA06 WA54 WA63 WB01 WC03

Claims (7)

[Claims] 1. A linear motion bearing penetrating a shaft so as to move linearly relative to a cylinder while maintaining a constant attitude with respect to the cylinder, wherein a plurality of grooves parallel to the axis are formed on an inner peripheral surface of the cylinder. A guide surface formed as a bottom portion of the groove faces the outer peripheral surface portion of the shaft, and a roller having an axis in the width direction of the concave groove is provided between the guide surface and the outer peripheral surface portion in a preloaded state. A return passage serving as a return movement path of the roller is formed through the body of the cylinder on the rear side of the guide surface, and the roller is provided at both ends of the cylinder with the guide surface and the outer peripheral surface. Between the guide path and the outer peripheral surface portion from one of the bent passages to the return passage from the other bent passage through the return passage. Circulation returning to a curved passage A roller holding belt circulating along a road is provided, and each of a number of roller loading holes penetrating the wall of the roller holding belt from front to back and arranged side by side at intervals in the longitudinal direction of the roller holding belt. The roller is rotatably mounted in such a manner that the outer periphery protrudes from both openings of the roller mounting hole, and the roller holding belt has a configuration wall thickness between the adjacent roller mounting holes. A linear motion bearing having a thickness smaller than a thickness of a portion where the roller loading hole is formed. 2. The linear motion bearing according to claim 1, wherein an outer surface of the component wall between the adjacent roller loading holes facing the outside of the circulation passage is the roller loading hole. A linear motion bearing which is formed flush with the outer surface in the forming portion. 3. The linear motion bearing according to claim 1, wherein the roller holding belt is formed of a flexible deformable synthetic resin mixed with reinforcing fibers. 4. The linear motion bearing according to claim 1, wherein a reinforcing wire continuous in a longitudinal direction of the roller holding belt is embedded in a constituent wall of the roller holding belt. Dynamic bearing. 5. The linear motion bearing according to claim 1, wherein the roller holding belt is formed in an endless ring shape bent along the circulation passage. 6. The linear motion bearing according to claim 1, wherein the roller holding belt is formed of a thin metal plate, and wherein the roller loading hole faces an opening formed by punching the thin metal plate and a peripheral edge of the opening. A linear motion bearing, which is a pair of protruding plate portions cut and raised in the same direction from a portion and rotatably holding a body portion of the roller. 7. A method for manufacturing the roller holding belt constituting the linear motion bearing according to claim 1, wherein a cylindrical forming die having forming irregularities formed on an outer peripheral surface thereof; Using a rotary molding machine comprising an auxiliary cylindrical mold parallel to the cylindrical molding die and an extruder for continuously extruding the plasticized resin, the plasticized resin continuously extruded from the extruder is rotated. A method for manufacturing a roller holding belt, wherein the roller holding belt is manufactured by passing a gap between the cylindrical forming die and the auxiliary cylindrical mold to each other, and cutting the continuous band-shaped body having passed through the gap to an appropriate length.