JP2009270623A - Roller bearing and linear motion guide - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a roller bearing enabling to autonomously restore the attitudes of rollers, when inclined, to be parallel to the axial direction of an inner ring shaft while avoiding the vibration of an outer ring. <P>SOLUTION: The roller bearing comprises the inner ring shaft 6, the cylindrical outer ring 5, the plurality of rollers 10 loaded on the circumference of an annular gap 3 between the inner ring shaft 6 and the outer ring 5, and a retainer 2 for turnably holding the rollers 10. The retainer 2 consists of a pair of retainer members 2a, 2b opposed to each other at a predetermined space in the axal direction of the rollers 10. The retainer members 2a, 2b have cutouts 20a, 20b for turnably holding the rollers 10 at their ends, and collar portions 21 for supporting the outer ring 5 at both ends. The inner ring shaft 6 has a flat D-cut face 61 formed by cutting the circular outer peripheral face into a sectional D-shape, as a portion to restore the oblique attitudes of the rollers 10. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a roller bearing and a linear motion guide device. More specifically, the present invention relates to a roller bearing having a configuration in which a plurality of rollers are loaded on a circumference in an annular gap between an inner ring shaft and an outer ring and rolled in the circumferential direction. The present invention relates to a roller bearing that can autonomously reset the skew posture of the roller, and a linear motion guide device incorporating the roller bearing.

Conventionally, a roller bearing shown in FIG. 8 is known (Patent Document 1). As shown in FIGS. 8 (a) and 8 (b), this roller bearing 101 is loaded circumferentially into an inner ring shaft 106, a cylindrical outer ring 105, and an annular gap 103 between the inner ring shaft 106 and the outer ring 105. The plurality of rollers 110 and a retainer 102 constituted by a pair of retainer members 102a and 102b that rotatably hold end portions of the respective rollers 110 are provided. When the outer ring 105 rotates in contact with the mating member, the roller bearing 101 rotates in the circumferential direction in the annular gap 103 between the inner ring shaft 106 and the outer ring 105, thereby Friction with the inner ring shaft 106 is greatly reduced. In such a linear bearing device in which the slider is configured to be movable relative to the rail in the length direction of the rail, the roller bearing 101 is configured such that the inner ring shaft is pivotally supported by the slider and the outer ring is the outer peripheral surface of the rail. It is arranged to roll in contact with the top.
JP 2002-310167 A

  By the way, the roller bearing 101 usually has an annular gap 103 between the outer ring 105 and the inner ring shaft 106 in which the roller 110 having a diameter half the difference between the inner diameter dimension of the outer ring 105 and the outer diameter dimension of the inner ring shaft 106. To be loaded. For this reason, when the posture of the roller 110 is tilted, the roller 110 may be skewed and skewed without being rolled. If it does so, a big friction will generate | occur | produce between the outer ring | wheel 105 and the inner ring | wheel axis | shaft 106, and the smooth rotation of an outer ring will be inhibited.

  If the inner diameter of the outer ring 105 is slightly increased to prevent skew, the outer ring 105 is pressed against the mating member to form a space S that is larger than the diameter of the roller 110 in the annular gap on the opposite side of the mating member. It is conceivable that the roller 110 passes through the space S so that the roller 110 is autonomously restored to a posture parallel to the axial direction of the inner ring shaft 106 even if the posture of the roller 110 is inclined. However, in this case, a difference L occurs in the axial center position of the inner ring shaft 106 depending on the position of the roller 110 that circulates around the inner ring shaft 106 (see FIGS. 9A and 9B). 105 shakes are generated.

  The present invention has been made in view of the above circumstances, and without causing the outer ring to sway, a roller bearing capable of autonomously reestablishing a posture parallel to the axial direction of the inner ring shaft even if the posture of the roller is inclined, and It is an object of the present invention to provide a linear motion guide device incorporating the roller bearing.

The roller bearing according to the present invention is
An inner ring shaft, a cylindrical outer ring that is sheathed on the inner ring shaft, a plurality of rollers that are loaded on the circumference in an annular gap between the inner ring shaft and the outer ring and roll in the circumferential direction, and each roller is rotated. It has a retainer that holds it freely,
The inner ring shaft is formed with a cut surface obtained by cutting a circular outer peripheral surface as a portion for restoring the skew posture of the roller.

With the above configuration, the roller that rolls around the annular gap and enters the cut surface beyond one end of the cut surface is brought into contact with the outer peripheral surface of the inner ring shaft and the inner peripheral surface of the outer ring. You are released from the state you were in. When this roller escapes from the cut surface, it comes into contact with the other end of the cut surface. Thereby, when the roller is in a skewed posture, the posture of the roller in the axial direction is matched with the axial direction of the inner ring shaft along the other end of the cut surface. In this way, the skewed roller posture can be reestablished by passing through the cut surface of the inner ring shaft. Accordingly, the roller that has escaped from the cut surface is smoothly rolled in the circumferential direction of the inner ring shaft.
Further, in the annular gap other than the cut surface, the plurality of rollers are fitted to the outer peripheral surface of the inner ring shaft and the inner peripheral surface of the outer ring, so that the outer ring does not shake with respect to the inner ring shaft.
In addition, since the roller is held by the retainer or the like, the roller is smoothly fitted to the inner ring shaft and the outer ring without stagnation on the cut surface.

The retainer is constituted by a pair of retainer members that are arranged to face each other at a predetermined interval in the axial direction of the roller, and each retainer member is provided with a plurality of notches that rotatably hold the end of the roller. , A collar portion is formed to support both end portions of the outer ring,
The cut surface formed on the inner ring shaft can be a flat D-cut surface obtained by cutting a circular outer peripheral surface into a D-shaped cross section.

  In this case, since the retainer is configured by a pair of retainer members and holds the end portions of the rollers, the rollers can be in a skewed posture unless the retainer members are rotated in synchronization. When the inner ring shaft and the outer ring rotate relative to each other and the retainer members also rotate, the retainer members are given a rotational force from the outer ring via the flange due to a difference in rotational speed between the retainer members and the outer ring. For this reason, the synchronization of the rotation of the retainer members may be shifted, and the rollers may be in a skewed posture. Further, if the roller is a needle having a small diameter, the skew posture is more likely to occur.

Even in this case, when the roller rolling around the annular gap enters the D-cut surface beyond one end of the D-cut surface, the outer peripheral surface of the inner ring shaft and the inner peripheral surface of the outer ring It is released from the state of being in contact with. When this roller escapes from the D-cut surface, it comes into contact with the other end of the D-cut surface. Thereby, when the roller is in a skewed posture, the posture of the roller in the axial direction matches the axial direction of the inner ring shaft along the other end side of the D-cut surface. In this way, the skewed roller posture can be reestablished by passing through the D-cut surface of the inner ring shaft. Therefore, the retainer is configured by a pair of retainer members that respectively hold both ends of each roller and support both ends of the outer ring, so that the D-cut surface of the inner ring shaft can be obtained even when the rollers are inclined. The roller posture that has been skewed can be reestablished by passing through. Therefore, the roller after escaping from the D-cut surface is smoothly rolled in the circumferential direction of the inner ring shaft.
Further, in the annular gap other than the D-cut surface, the plurality of rollers are fitted to the outer peripheral surface of the inner ring shaft and the inner peripheral surface of the outer ring, so that the outer ring does not shake with respect to the inner ring shaft.

On the other hand, the linear motion guide device according to the present invention is:
A rail and a slider arranged to be movable relative to the rail in the length direction of the rail,
An inner ring shaft of the roller bearing is pivotally supported in a concave groove provided in the slider, and an outer ring of the roller bearing is disposed so as to roll on the rail surface of the rail,
On the inner ring shaft of the roller bearing, a cut surface obtained by flatly cutting a circular outer peripheral surface as a part for reestablishing the skew posture of the roller is continuously formed to both ends of the inner ring shaft,
The concave groove that pivotally supports the inner ring shaft provided in the slider is formed in a rectangular shape having an opposing plane,
The cut surfaces at both ends of the inner ring shaft are arranged so as to be in contact with a plane on the side farther from the rail surface among opposed planes parallel to the rail surface on which the outer ring rolls in the concave groove. .

  With the configuration described above, the roller bearing can be reset to a posture parallel to the axial direction of the inner ring shaft by the cut surface of the inner ring shaft, so that the roller of the roller bearing can be smoothly rotated without causing skew. Moved. Therefore, the rotation of the outer ring of the roller bearing is performed stably and smoothly. As a result, smooth relative movement of the slider of the linear motion guide device is realized.

  On the other hand, when the outer ring of the roller bearing is pressed against the rail surface of the rail, the cut surface of the inner ring shaft is pressed against the flat surface of the concave groove of the slider. Therefore, in the roller bearing, the load applied to the inner ring shaft through the outer ring is received by the surface contact between the cut surface and the flat surface of the groove, so that the roller bearing can be adapted to a high load.

  In addition, since the inner ring shaft of the roller bearing has its cut surface in contact with the flat surface of the groove and the inner ring shaft is prevented from rotating, the inner ring shaft is prevented from slipping in the groove, and the inner ring shaft is worn. Damage or the like can be prevented, and the roller bearing can have a long life.

  Further, by making the concave groove of the slider rectangular, it is easy to adjust the dimensional accuracy at the time of processing the concave groove, and the slider can be manufactured easily and at low cost.

  As described above, according to the roller bearing according to the present invention, the skewed posture of the roller can be reset to the posture parallel to the axial direction of the inner ring shaft by the cut surface of the inner ring shaft, so that the roller may be skewed. It rolls smoothly. Further, since the plurality of rollers are fitted to the outer peripheral surface of the inner ring shaft and the inner peripheral surface of the outer ring in the annular gap other than the cut surface, the outer ring does not shake with respect to the inner ring shaft. Therefore, the relative rotation of the outer ring with respect to the inner ring shaft can be performed stably and smoothly without causing the outer ring to swing.

  According to the linear motion guide apparatus incorporating the roller bearing, the outer ring of the roller bearing is rotated smoothly and stably. As a result, smooth relative movement of the slider is realized.

Embodiments of the present invention will be described below with reference to the drawings.
As shown in FIGS. 1A and 1B, a needle roller bearing 1 as an embodiment of the present invention includes an inner ring shaft 6, a cylindrical outer ring 5 sheathed on the inner ring shaft 6, an inner ring shaft 6, A plurality of needle rollers (hereinafter referred to as “rollers”) 10 that are loaded circumferentially in an annular gap 3 between the outer ring 5 and roll in the circumferential direction, and a retainer 2 that rotatably holds each roller 10. And.

  As shown in FIG. 1 (b), the retainer 2 includes a first cylindrical retainer member 2a and a second retainer member 2b that are substantially cylindrical and are opposed to each other with a predetermined interval in the axial direction of the roller 10. ing. The inner ring shaft 6 may be provided with washers 15 and 16 on the sides of the first and second retainer members 2a and 2b, respectively. These washers 15 and 16 can restrict the movement of the first and second retainer members 2a and 2b in the axial direction. Therefore, for example, when the inner ring shaft 6 of the needle roller bearing 1 is pivotally supported by a shaft housing groove having a rectangular shape or the like, the retainer 2 comes into contact with the shaft housing groove to prevent rotation, or the contact causes the retainer 2 to rotate. Can be prevented from being damaged.

  As shown in FIG. 2, the first retainer member 2 a has a plurality of cutouts 20 a that rotatably support one end of the roller 10. Similarly, the second retainer member 2 b includes the roller 10. A plurality of cutouts 20b that rotatably support the other end of the cutouts are provided, and the cutouts 20a and 20b are arranged to face each other.

  The first retainer member 2a is provided with a convex portion 22a between adjacent notches 20a. Similarly, the second retainer member 2b is also provided with a convex portion 22b between adjacent notches 20b. The space 4 is formed between the convex portions 22a and 22b arranged to face each other. This void 4 constitutes a grease reservoir. As a result, the grease is applied directly to the rolling surfaces of the outer ring 5 and the inner ring shaft 6 and the rollers 10, and the rolling surfaces can be sufficiently and reliably lubricated. In addition, the grease reservoir is not formed concavely on the surface of the retainer, but is formed in the space 4 where no member exists between the first and second retainer members 2a and 2b. Even when the retainer 2 is thin like a bearing or when the outer diameter of the bearing is small and the distance between adjacent rollers 10 is very narrow, it is possible to reliably secure a grease reservoir and to exert a sufficient lubricating function. become.

  As shown in FIG. 1B, the first and second retainer members 2a and 2b are respectively formed with annular flange portions 21 that support both end portions of the outer ring 5. Thus, the axial distance between the first and second retainer members 2a and 2b can be kept constant via the outer ring 5, and the first and second retainer members 2a and 2b and the outer ring 5 are integrated. As a result, the needle roller bearing can be easily assembled.

  Further, in the flange portion 21 of the first and second retainer members 2a and 2b, an oil groove 26 is formed at a portion in contact with the outer ring 5, and an oil groove 28 is formed at the outer end face (FIG. 1). (See (b).) Thus, especially when the outer ring 5 rotates with the inner ring shaft 6 fixed, the oil groove 26 formed in the portion in contact with the outer ring 5 allows the outer ring 5 and the first and It is possible to prevent the retainer members 2a and 2b from being worn by the difference in rotational speed between the second retainer members 2a and 2b. In addition, the oil groove 28 formed on the outer end face can prevent wear between the washers 15 and 16 in contact with the outer end faces of the retainer members 2a and 2b.

  Further, the flange portion 21 is formed with a lip portion 24 having a tapered section in contact with the inner peripheral surface of the outer ring 5. As a result, the grease stored in the space 4 between the first and second retainer members 2a and 2b passes from the inner peripheral surface of the outer ring 5 to both ends of the outer ring 5 and the first and second retainer members 2a and 2b. It is possible to prevent leakage through the gap between the two.

  The inner ring shaft 6 is formed with a flat D-cut surface 61 in which a circular outer peripheral surface is cut into a D-shaped cross section as a portion for restoring the posture of the roller 10 (FIGS. 1A and 1B). reference). The D cut surface 61 is formed over the entire length of the inner ring shaft 6.

  As a result, when the roller 10 that rolls around the annular gap 3 enters the D cut surface 61 beyond one end 62 of the D cut surface 61, the outer peripheral surface of the inner ring shaft 6 and the outer ring 5 It is released from the state of being in contact with the inner peripheral surface. When this roller 10 escapes from the D-cut surface 61, it comes into contact with the other end 63 of the D-cut surface 61. Therefore, when the roller 10 is in the skew posture, the roller 10 is corrected so that the axial posture of the roller 10 is parallel to the axial direction of the inner ring shaft 6 along the other end 63 of the D-cut surface 61. The In this way, the skewed roller posture can be restored to a posture parallel to the axial direction of the inner ring shaft 6 by passing through the D-cut surface 61 of the inner ring shaft 6.

  Further, the width of the D-cut surface 61 is formed to a size that does not cause a difference in the axial center position of the inner ring shaft 6 depending on the positions of the plurality of rollers 10 that circulate around the inner ring shaft 6. For example, in the case shown in FIG. 1A, the width of the D-cut surface 61 is such that the rollers 10 are disposed on both ends 62 and 63, and one roller 10 is disposed on the D-cut surface 61. Is formed. As a result, in the annular gap 3 other than the D-cut surface 61, the plurality of rollers 10 are fitted to the outer peripheral surface of the inner ring shaft 6 and the inner peripheral surface of the outer ring 5. There is no waking.

  And as above-mentioned, the retainer 2 is comprised by a pair of retainer members 2a and 2b, and hold | maintains the both ends of each roller 10, respectively, If the rotation of each retainer member 2a and 2b is not synchronized, the roller 10 will incline It can be a posture. When the inner ring shaft 6 and the outer ring 5 rotate relative to each other and the retainer members 2 a and 2 b also rotate, the retainer members 2 a and 2 b are connected via the flange 21 due to a difference in rotational speed between the inner ring shaft 6 and the outer ring 5. Thus, a rotational force is applied from the outer ring 5. For this reason, the synchronism of rotation of the retainer members 2a and 2b is shifted, and the roller 10 may be in a skewed posture. Further, if the roller 10 is a needle having a small diameter, the skew posture is more likely to occur. Even in this case, the skewed roller posture by passing through the D-cut surface 61 of the inner ring shaft 6 can be restored to a posture parallel to the axial direction of the inner ring shaft 6. Accordingly, the roller 10 that has escaped from the D-cut surface 61 is smoothly rolled in the circumferential direction of the inner ring shaft 6.

  As described above, according to the needle roller bearing 1 according to the embodiment, the skew posture of the roller 10 can be reset to a posture parallel to the axial direction of the inner ring shaft 6 by the D-cut surface 61 of the inner ring shaft 6. The roller 10 is smoothly rolled without causing skew. Further, since the plurality of rollers 10 are fitted to the outer peripheral surface of the inner ring shaft 6 and the inner peripheral surface of the outer ring 5 in the annular gap 3 other than the D-cut surface 61, the outer ring 5 is prevented from swinging with respect to the inner ring shaft 6. There is no waking. Therefore, the relative rotation of the outer ring 5 with respect to the inner ring shaft 6 can be performed stably and smoothly without causing the outer ring 5 to swing.

The D-cut surface 61 of the inner ring shaft 6 is formed over the entire length of the inner ring shaft 6, but it may be formed only in the central part around which the roller 10 rotates.
A plurality of D-cut surfaces 61 may be provided in the circumferential direction of the inner ring shaft 6. However, it is necessary to set the number so as not to cause a difference in the axial center position of the inner ring shaft 6 depending on the positions of the plurality of rollers 10 that circulate around the inner ring shaft 6.
The width of the D-cut surface 61 may be formed so as not to cause a difference in the axial center position of the inner ring shaft 6 depending on the positions of the plurality of rollers 10 that circulate around the inner ring shaft 6. The size of the two rollers 10 may be arranged on the D-cut surface 61.

Further, the D-cut surface 61 is not limited to a flat cut surface, and may function as a curved surface, a concave surface, or the like having a larger R than the outer peripheral arc of the inner ring shaft 6 as long as it functions as a portion for restoring the skew posture of the roller 10. Various surface shapes may be used.
The retainer 2 is not limited to the above-described pair of retainer members 2a and 2b, and a retainer 2 provided with a plurality of rectangular holes for holding the rollers 10 on the side wall of the cylindrical body may be used.

Next, an example in which the needle roller bearing 1 is applied to a column guide as a linear motion bearing device will be described. As shown in FIG. 3, the column guide has a rail 8 that extends in a straight line and a slider 9 that can be reciprocated in the length direction with respect to the rail 8.
As shown in FIG. 4, the rail 8 has a first rail surface 8a and a second rail surface 8b that forms an angle θ with the first rail surface 8a, and these first and second rail surfaces 8a, 8b. Extends linearly along the direction of arrangement of the rails 8. Moreover, the cross-sectional shape of the rail 8 is formed symmetrically. The angle θ is set to 60 degrees in the case shown in FIG. 4, but is not limited to this angle.

  The slider 9 is configured by stacking and fixing a plurality of column members 90 having a substantially U-shaped or gate-shaped cross section (see FIG. 3). A plurality of substantially cross-shaped concave grooves 7 are respectively formed on the mating surfaces of the adjacent column members 90 (see FIG. 4). The above-described needle roller bearing 1 is accommodated in a space formed by the concave grooves 7 arranged to face each other in the adjacent column members 90. That is, the inner ring shaft 6 of the needle roller bearing 1 is pivotally supported by the shaft receiving groove 71 of the recessed groove 7, the outer ring 5 is received in the outer ring receiving groove 72 of the recessed groove 7, and the outer peripheral surface of the outer ring 5 is the rail 8. The rail surfaces 8a and 8b are in contact with each other. As a result, the outer ring 5 of each needle roller bearing 1 rotates around the inner ring shaft 6 while rolling on the rail surfaces 8 a and 8 b of the rail 8, so that the slider 9 moves relative to the rail 8. The friction is reduced in the length direction and the relative movement is smooth.

  The needle roller bearing 1 is accommodated in the concave groove 7 with washers 15 and 16 disposed on the sides of the first and second retainer members 2a and 2b, respectively. As a result, the first and second retainer members 2a and 2b come into contact with the shaft receiving groove 71 that supports the inner ring shaft 6, and the rotation of the retainer 2 is inhibited, or the contact causes the first and second retainer members to rotate. Problems such as breakage of 2a and 2b can be prevented. Further, since the washers 15 and 16 are brought into contact with the first and second retainer members 2a and 2b, the washers 15 and 16 can adjust the surface roughness of the contact surfaces of the first and second retainer members 2a and 2b. Stabilization can be achieved, and the width of the outer ring accommodating groove 72 of the concave groove 7 can be easily adjusted by adjusting the thickness of the washers 15 and 16.

  By the way, conventionally, the shaft housing groove for housing the inner ring shaft of the roller bearing in the concave groove provided in the slider has a similar R shape larger in the tolerance range than the shaft diameter of the inner ring shaft. A load applied to the outer ring of the roller bearing from the outer peripheral surface (rolling surface) of the rail is applied to the inner ring shaft through the roller, and is transmitted from the inner ring shaft to the slider. For this reason, the contact between the inner ring shaft and the shaft housing groove of the slider becomes a line contact, and when a high load is applied, the shaft housing groove is plastically deformed to generate a backlash of the roller bearing. In addition, since the shaft receiving groove is larger in the tolerance range than the shaft diameter of the inner ring shaft, the inner ring shaft of the roller bearing rotates with the movement of the slider, causing a slip or the like in the shaft receiving groove. The shaft receiving groove and the inner ring shaft of the slider may be damaged on the surface and the roller bearing may be loosened. In the worst case, a fatigue crack may be generated from the damaged portion and the shaft receiving groove or the inner ring shaft may be broken.

  As shown in FIG. 5, in the case of the present embodiment, the shaft housing groove 71 for housing the inner ring shaft 6 of the needle roller bearing 1 in the slider 9 is formed in a rectangular shape constituted by a plane. In addition, as shown in FIG. 6, the concave groove 7 including the shaft accommodating groove 71 may be formed in one of the adjacent column members 90, and the other column member 90 may cover this. The D-cut surface 61 of the inner ring shaft 6 is opposed to a plane 71b farther from the rail surface 8a (8b) among the opposed planes 71a and 71b parallel to the rail surface 8a (8b) that is the rolling surface of the outer ring 5. Arranged to touch. As a result, when the outer ring 5 is pressed against the rail surface 8 a (8 b) of the rail 8, the D-cut surface 61 of the inner ring shaft 6 is pressed against the flat surface 71 b of the rectangular shaft receiving groove 71 and passes through the outer ring 5 to the inner ring shaft 6. The applied pressing force is received by the surface contact between the D-cut surface 61 and the shaft housing groove 71. Therefore, according to the needle roller bearing 1, since the load is received by the surface contact between the D-cut surface 61 of the inner ring shaft 6 and the flat surface 71b of the shaft housing groove 71, the needle roller bearing 1 can cope with a high load. .

  Further, since the inner ring shaft 6 is prevented from rotating because the D-cut surface 61 is in contact with the flat surface 71 b of the shaft receiving groove 71, the inner ring shaft 6 is prevented from slipping in the shaft receiving groove 71. The inner ring shaft 6 can be prevented from being damaged and the needle roller bearing 1 can have a long life.

  Further, in addition to the shaft housing groove 71 for housing the inner ring shaft 6 in the slider 9, the concave groove (including the outer ring housing groove 72) 7 for disposing the needle roller bearing 1 is also formed into a rectangular shape. 7 can be easily adjusted in dimensional accuracy, and the slider 9 can be manufactured easily and at low cost.

  From the above, in the needle roller bearing 1, since the skew posture of the roller 10 is autonomously reestablished, the outer ring 5 is rotated smoothly and stably. As a result, the slider 9 is smoothly moved. Relative movement is realized. In addition, since the needle roller bearing 1 can be made to handle a high load, a column guide can be obtained that is less likely to cause backlash of the needle roller bearing 1 even under a high load.

  The shaft housing groove for housing the inner ring shaft 6 of the needle roller bearing 1 may be, for example, a semicircular shape as shown in FIG. It may be a shaft receiving groove 71 ′. As shown in FIG. 7, the D-cut surface 61 of the inner ring shaft 6 may be disposed so as to be in contact with a plane 71c perpendicular to the rail surface 8a (8b) in the shaft receiving groove 71 '. Even in these cases, since the inner ring shaft 6 is prevented from rotating because the D-cut surface 61 is in contact with the flat surface 71c of the shaft receiving groove 71 ′, the inner ring shaft 6 slips in the shaft receiving groove 71. Etc. are prevented, damage to the inner ring shaft 6 and the like can be prevented, and the needle roller bearing 1 can have a long life.

  Further, the column guide has various shapes such as a cylindrical sleeve inserted through a cylindrical sleeve and a needle roller bearing 1 disposed between the post and the sleeve. be able to.

FIG. 2 is a partial cross-sectional view showing a configuration of a needle roller bearing according to an embodiment, where FIG. 1A is a partial cross-sectional view perpendicular to the inner ring shaft, and FIG. 2B is a partial cross-sectional view of the inner ring shaft in the axial direction. It is. It is the elements on larger scale which show the structure of a retainer member. It is a perspective view which shows the external appearance of the column guide incorporating the needle roller bearing by embodiment. It is sectional drawing which shows the internal structure of the column guide incorporating the needle roller bearing by embodiment. It is sectional drawing which shows the arrangement | positioning position of the inner ring | wheel axis | shaft of the needle roller bearing in the shaft accommodation groove | channel of a slider. It is sectional drawing which showed the modification of the shaft accommodating groove | channel of a slider. It is sectional drawing which showed the other modification of the shaft accommodation groove | channel of a slider. FIG. 2 is a partial cross-sectional view showing a configuration of a conventional roller bearing, in which FIG. 1A is a partial cross-sectional view perpendicular to the inner ring shaft, and FIG. 2B is a partial cross-sectional view of the inner ring shaft in the axial direction. . It is a schematic diagram for explaining runout of the outer ring when the diameter of the outer ring is increased in the roller bearing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Needle roller bearing 2 Retainer 2a, 2b Retainer member 3 Annular gap 5 Outer ring 6 Inner ring shaft 7 Concave groove 8 Rail 9 Slider 10 Roller 61 D cut surface 71 Shaft accommodation groove 72 Outer ring accommodation groove

Claims (3)

An inner ring shaft, a cylindrical outer ring that is sheathed on the inner ring shaft, a plurality of rollers that are loaded on the circumference in an annular gap between the inner ring shaft and the outer ring and roll in the circumferential direction, and each roller is rotated. It has a retainer that holds it freely,
A roller bearing in which a cut surface obtained by cutting a circular outer peripheral surface is formed on the inner ring shaft as a portion for restoring the skew posture of the roller. The roller bearing according to claim 1,
The retainer is constituted by a pair of retainer members that are arranged to face each other at a predetermined interval in the axial direction of the roller, and each retainer member is provided with a plurality of notches that rotatably hold the end of the roller. , A collar portion is formed to support both end portions of the outer ring,
The roller bearing formed on the inner ring shaft is a flat D-cut surface obtained by cutting a circular outer peripheral surface into a D-shaped cross section. A rail and a slider arranged to be movable relative to the rail in the length direction of the rail,
The inner ring shaft of the roller bearing according to claim 1 or 2 is pivotally supported by a concave groove provided in the slider, and the outer ring of the roller bearing is arranged to roll on the rail surface of the rail,
On the inner ring shaft of the roller bearing, a cut surface obtained by flatly cutting a circular outer peripheral surface as a part for reestablishing the skew posture of the roller is continuously formed to both ends of the inner ring shaft,
The concave groove that pivotally supports the inner ring shaft provided in the slider is formed in a rectangular shape having an opposing plane,
The linear guides are arranged so that the cut surfaces at both ends of the inner ring shaft are in contact with a plane farther from the rail surface among the opposed planes parallel to the rail surface on which the outer ring rolls in the concave groove. apparatus.

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