Side-roller attachment structure and chain equipped with side roller

Abstract

This side-roller attachment structure comprises a side roller (40) that is rotatably supported by an insertion shaft (32) having a circular cross-section and projecting from a side portion of a movable body. The side roller (40) is provided with a roller member (42), a bearing (41) that rotatably supports the roller member (42), and a cylindrical sleeve (33) mounted on the inner circumferential side of the bearing (41). The insertion shaft (32) includes a locking unit (50) provided with a locking member capable of protruding outward in the radial direction of the insertion shaft (32). The sleeve (33) receives the locking unit (50) on the inner circumference of the sleeve (33) to cause the locking unit (50) to slide, and includes a locking section (33d). The locking section (33d) locks the locking unit (50).

Description

TITLE OF INVENTION: SIDE-ROLLER ATTACHMENT STRUCTURE AND CHAIN EQUIPPED WITH SIDE ROLLER TECHNICAL FIELD

[0001] The present disclosure relates to a side-roller attachment structure and a chain including a side roller, and more particularly to a side-roller attachment structure that allows a side roller to be readily attached to and detached from a moving member such as a chain, and to a chain including such a side roller. BACKGROUND ART

[0002] Conventionally, side rollers that are mounted on side portions of moving members such as chains and that roll to convey articles in a stable manner, as well as chains including such side rollers on side portions of the chains, have been used.

[0003] Fig. 15 is a partially cutaway perspective view of a side roller 140 mounted on an outer link plate 117 of a chain 112 described in Patent Literature 1, which is a conventional technique. Fig. 16 is a cross-sectional view of the conventional side roller 140 before an insert pin 132 is inserted. Fig. 17 is a cross-sectional view showing the side roller 140 shown in Fig. 16 with the insert pin 132 inserted therein.

[0004] As shown in Fig. 16, in the chain 112 to which the side roller 140 disclosed in Patent Literature 1 is mounted, an insert-pin retaining ring 135 is fitted in a sleeve groove 133a formed in an inner periphery of a sleeve 133. As shown in Fig. 17, an insert-pin groove 132a is formed at a distal end of the insert pin 132. When the insert pin 132 is inserted into the sleeve 133, a fixing plate 136 is inserted while forcing the insert-pin retaining ring 135 outward along an outer surface of the fixing plate 136. When the insert-pin groove 132a reaches the position of the insert-pin retaining ring 135, the insert-pin retaining ring 135 snaps into the insert-pin groove 132a by its elasticity. The insert pin 132 is thereby fixed to the sleeve 133. In this manner, the side roller 140 is fixed to the insert pin 132. CITATION LIST Patent Literature

[0005] Patent Literature 1: WO2017 / 103183A SUMMARY OF INVENTION Technical Problem

[0006] However, in the configuration described in Patent Literature 1, the operation of attaching the side roller 140 to the insert pin 132 is complicated. In addition, since the side roller 140 is fixed using the flexible insert-pin retaining ring 135, the fixing strength is relatively low, and improved fixing strength is desired.

[0007] An object of the side-roller attachment structure and the chain including a side roller of the present disclosure is to facilitate attachment of a side roller to, and removal of the side roller from, a moving member such as a chain, while allowing the side roller to be firmly fixed. Solution to Problem

[0008] In accordance with one aspect of the present disclosure, a side-roller attachment structure includes a side roller rotatably supported by an insertion shaft having a circular cross section and projecting from a side portion of a moving member. The side roller includes a roller member, a bearing that rotatably supports the roller member, and a hollow cylindrical sleeve attached to an inner peripheral side of the bearing. The side-roller attachment structure is configured to attach the roller member to the insertion shaft via the sleeve. The insertion shaft includes a locking unit including a locking member capable of protruding radially outward from the insertion shaft. The sleeve receives the locking unit on an inner periphery of the sleeve, allows the locking unit to slide, and includes a locking portion. The locking portion engages the locking unit.

[0009] A chain with a side roller according to one aspect of the present disclosure includes the above-described side roller and a chain as the moving member. BRIEF DESCRIPTION OF DRAWINGS

[0010] [Fig. 1] Fig. 1 is a partially cutaway plan view showing a portion of a chain including side rollers according to one embodiment. [Fig. 2] Fig. 2 is a perspective view showing an insert pin and a cutaway view of a side roller before the insert pin is inserted. [Fig. 3] Fig. 3 is a cross-sectional view showing the insert pin and the side roller before the insert pin is inserted. [Fig. 4] Fig. 4 is a front view of the side roller of the present embodiment as viewed in a Y direction. [Fig. 5] Fig. 5 is a cross-sectional view taken along line V-V in Fig. 4. [Fig. 6] Fig. 6 is a cross-sectional view taken along line VI-VI in Fig. 4. [Fig. 7] Fig. 7 is a perspective view showing a cross section of a sleeve. [Fig. 8] Fig. 8 is an exploded perspective view of a claw unit. [Fig. 9] Fig. 9 is a front view of the claw unit as viewed in a movement direction X. [Fig. 10] Fig. 10 is a cross-sectional view taken along line X-X in Fig. 9. [Fig. 11] Fig. 11 is a cross-sectional view taken along line XI-XI in Fig. 10. [Fig. 12] Fig. 12 is a perspective view of a second embodiment. [Fig. 13] Fig. 13A is a front view of an insert pin of the second embodiment as viewed in the Y direction. Fig. 13B is a cross-sectional view taken along line XII(b)-XII(b) in Fig. 13A. [Fig. 14] Fig. 14A is a side view of a sleeve of the second embodiment as viewed in an X direction. Fig. 14B is a cross-sectional view taken along line XIV(b)-XIV(b) in Fig. 14A. [Fig. 15] is a partially cutaway perspective view of a side roller attached to an outer link of a chain described in Patent Literature 1. [Fig. 16] is a cross-sectional view showing a state before an insert pin is inserted into the conventional side roller shown in Fig. 15. [Fig. 17] is a cross-sectional view showing a state in which the insert pin is inserted into the side roller shown in Fig. 16. DESCRIPTION OF EMBODIMENTS

[0011] A side-roller attachment structure in a chain 11 including side rollers, in which side rollers 40 are attached to a chain 12, will now be described as an embodiment of the sideroller attachment structure of the present disclosure with reference to Figs. 1 to 14B.

[0012] <Problems of Prior Art> The conventional attachment structure for the side roller 140 has the problems described above. Since the present embodiment also addresses the following issues, additional explanation is provided below.

[0013] In the conventional technology disclosed in Patent Literature 1, an insert pin 132, which is an insertion shaft, is inserted into the side roller 140 shown in Fig. 16, as shown in Fig. 17. An annular fixing plate 136 having a tapered distal end is fastened and fixed to a distal end of the insert pin 132 by a bolt 134. A recess is formed in a peripheral edge on a proximal side of the fixing plate 136. When the fixing plate 136 is attached to the insert pin 132 by the bolt 134, an annular insert-pin groove 132a is formed around a peripheral edge of the distal end of the insert pin 132.

[0014] An annular sleeve groove 133a is formed in an inner peripheral surface of the sleeve 133 at a position deeper in the insertion direction. A flexible insert-pin retaining ring 135 is fitted in the annular sleeve groove 133a.

[0015] When the insert pin 132 is inserted into the sleeve 133, the fixing plate 136 deflects and forces outward the flexible annular insert-pin retaining ring 135, allowing the insert pin 132 to advance. When the insert-pin groove 132a reaches the position of the insert-pin retaining ring 135, the insert-pin retaining ring 135 snaps into the insert-pin groove 132a by its elasticity. The insert pin 132 is thereby fixed to the sleeve 133 by the insert-pin retaining ring 135. In this manner, the side roller 140 is fixed to the insert pin 132. A roller member 142 can be smoothly rotated relative to the insert pin 132 by ball bearings 141.

[0016] In a configuration such as that disclosed in Patent Literature 1, the insert pin 132 and the sleeve 133 are fixed relative to each other by friction between the insert-pin groove 132a and the insert-pin retaining ring 135 and by friction between the sleeve groove 133a and the insert-pin retaining ring 135. However, the rotational resistance of the ball bearings 141 may increase due to wear, entry of foreign matter, deterioration of lubricant, or the like. In such a case, if the rotational resistance of the ball bearings 141 becomes greater than the frictional force between the insert pin 132 and the sleeve 133, slippage may occur between the insert pin 132 and the sleeve 133. If such slippage occurs, wear may also occur in the insert pin 132, the fixing plate 136, the insert-pin retaining ring 135, the sleeve groove 133a, and the like.

[0017] Accordingly, in Patent Literature 1, rotation of the sleeve 133 is suppressed by engaging an anti-rotation device 137 provided at a proximal end portion of the insert pin 132 with a notch of a stopper 133b at an opening of the sleeve 133. However, in this structure, the notch positions must be aligned at the final stage of inserting the insert pin 132 into the sleeve 133. At this stage, there is no clearance between the outer peripheral surface of the insert pin 132 and the outer peripheral surface of the sleeve 133. In addition, the insert-pin retaining ring 135 is being pushed in while being deflected by the fixing plate 136 of the insert pin 132, and the outward projecting force of the insert-pin retaining ring 135 acts strongly on the outer peripheral surface of the fixing plate 136. This makes it difficult to rotate the insert pin 132 to align the notch positions.

[0018] In addition, the insert-pin retaining ring 135 must be flexible so that it can be installed in the sleeve groove 133a and the insert-pin groove 132a by elastic deformation. As a result, the insert-pin retaining ring 135 is not high in strength and is therefore prone to displacement also in the insertion direction.

[0019] <Overview of the Present Embodiment> In the present embodiment, when an insert pin 32, which is an insertion shaft, is inserted into a side roller 40, the structure of a claw unit 50 allows the side roller 40 to be fixed to the insert pin 32 in one operation without tightening the bolt 134 as in the conventional structure.

[0020] In addition, since claw members 51 of the claw unit 50 have a relatively high rigidity, the side roller 40 can be fixed to the insert pin 32 with a relatively high fixing strength. Further, the insert pin 32 is provided with a guide groove 32g extending in the insertion direction, and positioning pins 33h projecting inward from a sleeve 33 restrict relative rotation between the insert pin 32 and the sleeve 33.

[0021] These features will be described in detail below. <First Embodiment> A chain 11 including side rollers according to a first embodiment will now be described with reference to Figs. 1 to 11.

[0022] As shown in Fig. 1, a chain 11 including side rollers includes a chain 12 as an example of a moving member, and side rollers 40 rotatably provided on insert pins 32 projecting from side portions of the chain 12. As the chain 12 moves, the side rollers 40 move in a movement direction X while rolling on rails (not shown).

[0023] <Chain 12> The chain 12 includes multiple inner links 16 and multiple outer links 18. Each inner link 16 includes a pair of inner link plates 15 that face each other in a width direction Y and are spaced apart from each other. Each outer link 18 includes a pair of outer link plates 17 arranged so as to sandwich, from the outer side in the width direction Y, the inner link plates 15 of two inner links 16 adjacent to each other. The inner link plates 15 of the inner links 16 and the outer link plates 17 of the outer links 18 each have a generally rectangular plate shape extending in the movement direction X.

[0024] The inner link plates 15 and the outer link plates 17 that face each other in the width direction Y are arranged parallel to each other. Accordingly, the chain 12 of the present embodiment is a flat-type chain configured such that the spacing between the inner link plates 15 and the spacing between the outer link plates 17 are each equal at one end and the other end of the inner links 16 and the outer links 18 in the movement direction X.

[0025] Circular bushing insertion holes 15a are formed at the opposite end portions of each inner link plate 15 in the movement direction X so as to extend through the inner link plate 15 in the width direction Y, which is also the thickness direction of the inner link plate 15. Two hollow cylindrical bushings 19 are disposed between the pair of inner link plates 15 facing each other in each inner link 16 so as to maintain the distance between the inner link plates 15. Opposite end portions of each bushing 19 are respectively fitted into the bushing insertion holes 15a of the pair of inner link plates 15. Each bushing 19 is inserted through a hollow cylindrical roller 20 and thereby rotatably supports the roller 20. That is, the bushing 19 is loosely fitted into the roller 20.

[0026] <Shaft Member 30> Circular pin insertion holes 17a are respectively formed at the opposite end portions of each outer link plate 17 in the movement direction X so as to extend through the outer link plate 17 in the width direction Y, which is also the thickness direction of the outer link plate 17. A cylindrical shaft member 30 having an outer diameter slightly smaller than the inner diameter of the bushing 19 is inserted and fitted into each pin insertion hole 17a.

[0027] The shaft member 30 includes a chain pin 31 at a central portion in the width direction Y. The chain pin 31 serves as a connecting shaft for connecting the outer link plates 17 to each other. The shaft member 30 also includes insert pins 32 at opposite end portions in the width direction Y, the insert pins 32 projecting from the outer link plates 17.

[0028] Each inner link 16 is formed with the bushing 19 mounted between the pair of inner link plates 15. The outer link plates 17 of each outer link 18 are rotatably connected to the inner link plates 15 of the inner links 16 via the shaft members 30 from the outer side of the inner link plates 15.

[0029] In this case, the shaft member 30 is in a state in which the chain pin 31 is inserted into the bushing 19 assembled between the pair of inner link plates 15 of the inner link 16. In this state, the opposite end portions of the chain pin 31 are fitted into the pin insertion holes 17a of the pair of outer link plates 17 of the outer link 18. Accordingly, the shaft member 30 extends through the pair of outer link plates 17. In addition, the inner link plates 15 of an inner link 16 and the outer link plates 17 of an outer link 18 that are adjacent to each other in the movement direction X are pivotably connected to each other at their end portions in the movement direction X via a chain pin 31 and a bushing 19. The chain 12 of the present embodiment is made of steel.

[0030] <Insert Pin 32> Fig. 2 is a perspective view showing an insert pin 32 and a cutaway view of a side roller 40 before the insert pin 32 is inserted. Fig. 3 is a cross-sectional view showing the insert pin 32 and the side roller 40 before the insert pin 32 is inserted. Fig. 4 is a side view of the side roller 40 into which the insert pin 32 has been inserted as viewed from the outer side in the width direction Y. Fig. 5 is a cross-sectional view taken along line V-V in Fig. 4. Fig. 6 is a cross-sectional view taken along line VI-VI in Fig. 4.

[0031] As shown in Fig. 1, the opposite ends of the shaft member 30 form insert pins 32 having a reduced diameter. Movement of the shaft member 30 in the width direction Y is restricted by attaching the side rollers 40 to the insert pins 32.

[0032] As shown in Fig. 2, each insert pin 32 has a cylindrical shape. The insert pin 32 includes an outer peripheral surface 32c forming a side surface of the insert pin 32. The outer peripheral surface 32c has a shape including a large-diameter portion 32d forming a proximal portion adjacent to the chain 12, a small-diameter portion 32e forming a distal portion and having a smaller diameter than the large-diameter portion 32d, and a stepped portion 32f formed by an inclined surface connecting the large-diameter portion 32d and the small-diameter portion 32e.

[0033] <Side Roller 40> As shown in Figs. 2 and 3, each side roller 40 is fixed by insertion of the insert pin 32. The side roller 40 includes a hollow cylindrical roller member 42, ball bearings 41 as an example of bearings, and a sleeve 33. The roller member 42 is rotatably supported relative to the insert pin 32 via the ball bearings 41 and rolls as the chain 12 moves in the movement direction X. In the present embodiment, two ball bearings 41 are provided so as to be adjacent to each other in the width direction Y, which is also the axial direction of the ball bearings 41.

[0034] <Ball Bearings 41> As shown in Fig. 5, each ball bearing 41 includes an annular inner ring 41a, or inner race, fixed to the outer peripheral surface 32c of the insert pin 32 via the sleeve 33. Each ball bearing 41 also includes an annular outer ring 41b, or outer race, fixed to an inner peripheral surface 42a of the roller member 42. The ball bearing 41 further includes multiple balls 41c. The balls 41c are interposed between the inner ring 41a and the outer ring 41b, are arranged in a single row at predetermined intervals in the circumferential direction, and are held by a retainer, not shown.

[0035] As shown in Fig. 5, of the two ball bearings 41, the ball bearing 41 located adjacent to the chain 12 (on the lower side as viewed in Fig. 5) has the inner ring 41a in contact with the stepped portion 33c of the sleeve 33. The outer ring 41b of this ball bearing 41 contacts a lower corner portion 42b of the inner peripheral surface 42a of the roller member 42, thereby restricting displacement in the insertion direction (the width direction Y).

[0036] Further, of the two ball bearings 41, the outer ring 41b of the ball bearing 41 located outward (on the upper side as viewed in Fig. 5) contacts an annular retaining ring 45 fitted in an annular groove 42c formed in the inner peripheral surface 42a of the roller member 42, thereby restricting displacement in the width direction Y.

[0037] In addition, of the two ball bearings 41, the inner ring 41a of the ball bearing 41 on the side opposite the chain 12 (on the upper side as viewed in Fig. 5) contacts, at an upper portion thereof (as viewed in Fig. 5), an annular retaining ring 33g fitted in an annular groove 33f formed in the outer peripheral surface 33e of the sleeve 33, thereby restricting displacement in the width direction Y.

[0038] A lubricant used inside each ball bearing 41 may be, for example, a synthetic resin impregnated with grease or the like. <Sleeve 33> Fig. 7 is a perspective view showing a cross section of the sleeve 33. As described above, the sleeve 33 is arranged on the inner peripheral side of the side roller 40. Specifically, the sleeve 33 is arranged further inward than the inner rings 41a of the ball bearings 41 arranged on the inner periphery of the roller member 42. By mounting the sleeve 33 to the insert pin 32, the roller member 42 is attached to the insert pin 32. In other words, the roller member 42 is mounted to the insert pin 32 via the sleeve 33. The portion of the sleeve 33 not shown in Fig. 7 is symmetrical with respect to the cut surface shown in Fig. 7, and the sleeve 33 as a whole is a hollow cylindrical member. The sleeve 33 includes a large-diameter portion 33a on the side adjacent to the chain 12, which is shown lower in Fig. 7. The sleeve 33 also includes a small-diameter portion 33b on the side opposite the chain 12, which is shown upper in Fig. 7, the small-diameter portion 33b having a smaller diameter than the large-diameter portion 33a. The sleeve 33 further includes, at a position slightly below the center of the outer peripheral surface 33e in the height direction (the width direction Y), a stepped portion 33c connecting the large-diameter portion 33a and the smalldiameter portion 33b. The stepped portion 33c supports the lower end of the inner ring 41a of the ball bearing 41 located adjacent to the chain 12. An upper end portion of the outer peripheral surface 33e includes a groove 33f for fixing an upper portion of the inner ring 41a of the ball bearing 41 located outward, and the ball bearing 41 is fixed via a retaining ring 33g (see Fig. 5).

[0039] The upper end surface of the sleeve 33 forms a locking portion 33d with which the locking claws 51b of the claw members 51 are engaged (see Fig. 6). As shown in Fig. 7, a pair of positioning-pin holes 33i, 33i are formed in an upper portion of the sleeve 33 so as to extend through an inner peripheral surface 33k and the outer peripheral surface 33e, and are arranged in the insertion direction (the width direction Y). As shown in Fig. 5, positioning pins 33h are inserted through the positioning-pin holes 33i, 33i. As shown in Fig. 2, the positioning pins 33h project into the interior of the sleeve 33. When the insert pin 32 is inserted, the positioning-pin holes 33i, 33i slide in the guide groove 32g formed in the outer peripheral surface 32c of the insert pin 32 (see Fig. 2).

[0040] <Lid Member 43> As shown in Fig. 5, an annular step 42d is formed around the inner circumference of an opening at a distal end portion of the roller member 42, which is tubular as a whole and is shown at the top in Fig. 5, the step 42d defining an inner diameter smaller than that of the opening. A disc-shaped lid member 43 is mounted to the step 42d so as to seal the interior of the roller member 42. A seal-member receiving groove 42e that receives a seal member 43a is formed in the inner periphery of the opening of the roller member 42 at a position above the step 42d. The lid member 43 is fitted in place with an outer peripheral edge of the lid member 43 sealed by the seal member 43a received in the seal-member receiving groove 42e.

[0041] The lid member 43 seals the opening with a lower peripheral edge of the lid member 43 in contact with the step 42d. An annular retaining-ring receiving groove 42f is formed in the inner peripheral surface 42a of the opening of the roller member 42. A retaining ring 43b is received in the retaining-ring receiving groove 42f while being urged outward by its elasticity. The retaining ring 43b prevents the lid member 43 from coming out of the roller member 42.

[0042] <Seal Chamber 46> As shown in Fig. 6, an annular seal chamber 46 is formed in a portion between the roller member 42 and the sleeve 33 at a position that is adjacent to a ball bearing 41 and between the ball bearing 41 and the chain 12 in the width direction Y. The seal chamber 46 is defined by the roller member 42, the insert pin 32, and the ball bearing 41. An oil seal, not shown, is disposed in the seal chamber 46 as an example of a seal member. The seal chamber 46 prevents metal powder and contaminated water near the chain 12 from entering. Examples of the oil seal include a contact-type seal member using elastic force, a noncontact labyrinth seal, and a felt seal.

[0043] <Claw Unit 50> As shown in Figs. 2 and 3, a claw unit 50, which is an example of a locking unit, is disposed at the distal end of the insert pin 32 in the insertion direction. The claw unit 50 is fastened to the distal end of the insert pin 32 by a bolt 34. The claw unit 50 includes claw members 51, a support plate 52, slide bars 53, springs 54, and a bushing 55.

[0044] Fig. 8 is an exploded perspective view of the claw unit 50. Fig. 9 is a front view of the claw unit 50 as viewed in the movement direction X. Fig. 10 is a cross-sectional view taken along line X-X in Fig. 9. Fig. 11 is a cross-sectional view taken along line XI-XI in Fig. 10.

[0045] <Support Plate 52> As shown in Fig. 8, a distal end surface 32i of the cylindrical insert pin 32 is flat. A bottom portion 52a of a disc-shaped support plate 52 having a cutout 52f is disposed on the distal end surface 32i so as to cover the distal end surface 32i of the insert pin 32. The cutout 52f is formed by cutting away a portion of the outer periphery of the disc-shaped support plate 52 in a straight line through the thickness of the support plate 52. The cutout 52f is formed at a position corresponding to a restricting portion 32j that protrudes in the axial direction from the distal end surface 32i of the insert pin 32. Accordingly, the support plate 52 contacts the restricting portion 32j, which protrudes into the cutout 52f. The restricting portion 32j of the insert pin 32 has a height such that the restricting portion 32j is flush with the bottom portion 52a. Accordingly, rotation of the support plate 52 about the central axis C is restricted. The support plate 52 has wall portions 52b and 52c that rise upright at peripheral regions near the cutout 52f and across from the cutout 52f in the radial direction of the support plate 52. The wall portions 52b and 52c extend in a curved manner along the outer periphery of the support plate 52 and have a substantially constant thickness. Between the wall portions 52b and 52c, a pair of opposing flat openings 52d, 52d having no wall portions are formed.

[0046] <Claw Members 51> As shown in Fig. 10, a pair of claw members 51, 51 are disposed on the bottom portion 52a of the support plate 52, radially inward of the wall portions 52b and 52c. Each claw member 51 includes an arc-shaped main body 51a extending along the inner peripheries of the wall portions 52b and 52c. A tongue-shaped locking claw 51b is provided so as to extend outward from a central portion of the main body 51a.

[0047] <Main Body 51a> As shown in Fig. 11, the locking claw 51b of each claw member 51 is guided by an inner surface of the opening 52d and is displaceable radially outward and inward in a direction perpendicular to the width direction Y. Accordingly, each claw member 51 is displaced between a protruding position shown by a solid line and a retracted position shown by a long-dash double-short-dash line, so that the locking claw 51b can protrude from the support plate 52 or be retracted into the support plate 52. As shown in Figs. 8 and 10, each claw member 51 has an arc-shaped main body 51a. Guide holes 51c, 51c are formed through opposite end portions of the main body 51a. The guide holes 51c, 51c of the claw members 51 are positioned so as to face each other in a protruding direction. A slide bar 53 is inserted through the guide holes 51c, 51c that face each other in the protruding direction. Accordingly, the pair of claw members 51 are guided by the slide bars 53 and move relative to each other in protruding and retracting directions while maintaining their orientations. When the pair of claw members 51 are in their most separated state, the main bodies 51a contact the inner peripheries of the wall portions 52b and 52c, thereby restricting the positions of the claw members 51 in the protruding direction. In this state, the locking claws 51b protrude from the openings 52d of the support plate 52. In addition, springs 54, each of which is a compression spring formed of a helical spring, are fitted on the respective slide bars 53 and urge the main bodies 51a of the pair of claw members 51 in directions away from each other.

[0048] <Locking Claw 51b> Each locking claw 51b is a tongue-shaped portion that extends radially outward from a central portion of the main body 51a into the opening 52d and is displaceable radially outward and inward within the opening 52d. Each locking claw 51b is tapered so as to slope in the protruding direction from a leading end in the insertion direction toward a proximal end of the insert pin 32. Each locking claw 51b has the shape of a claw including a substantially planar inclined surface 51d (see Fig. 8). In other words, a normal to the inclined surface 51d is inclined outward in the insertion direction. A surface of each locking claw 51b facing the support plate 52 is a flat surface parallel to the bottom portion 52a. When the insert pin 32 is inserted, the inclined surface 51d contacts an inclined surface 33l of the inner peripheral surface 33k of the sleeve 33, thereby causing the locking claw 51b to be pushed radially inward. In other words, each locking claw 51b is pushed into the support plate 52. This allows the locking claw 51b of each claw member 51 to move in the insertion direction along the inner peripheral surface 33k of the sleeve 33. The insert pin 32 can therefore be smoothly inserted into the sleeve 33.

[0049] <Bushing 55> The bushing 55 shown in Fig. 8 is a member including a tubular portion 55a, which is a hollow cylindrical portion, and a flange portion 55b formed in a flange shape at a leading end portion of the tubular portion 55a in the insertion direction. The tubular portion 55a of the bushing 55 is inserted into a circular through-hole 52e formed at the center of the support plate 52. The outer diameter of the tubular portion 55a is substantially equal to the inner diameter of the through-hole 52e. The outer diameter of the flange portion 55b is such that a peripheral edge of the flange portion 55b contacts the inner peripheries of the wall portions 52b and 52c of the support plate 52. Accordingly, when the tubular portion 55a of the bushing 55 is inserted into the through-hole 52e of the support plate 52 accommodating the claw members 51, the flange portion 55b holds the claw members 51 in a displaceable manner. The inner diameter of the tubular portion 55a of the bushing 55 is substantially equal to the thread diameter of the bolt 34.

[0050] <Bolt 34> As shown in Fig. 8, the bolt 34 can be screwed into a threaded hole 32h of the insert pin 32. In other words, when the bolt 34 is inserted through a through-hole 55c of the bushing 55 and is screwed into the threaded hole 32h of the insert pin 32, the claw unit 50 is attached and fixed to the distal end of the insert pin 32.

[0051] (Operation of the First Embodiment) The chain 11 including side rollers configured as described above operates as follows. <Attachment of the Side Roller 40 to the Insert Pin 32> As shown in Fig. 2, the insert pin 32 is inserted into the sleeve 33 of the side roller 40. At this time, the locking claws 51b shown in Fig. 8 pass along the inner peripheral surface 33k of the large-diameter portion 33a of the sleeve 33 while remaining in their protruding state. The insert pin 32 can therefore be readily rotated relative to the side roller 40 about the central axis C.

[0052] When the insert pin 32 is inserted further, the tips of the locking claws 51b contact the inclined surface 33l of the inner peripheral surface 33k of the sleeve 33 (see Fig. 7). In addition, the positioning pin 33h may interfere with part of the claw unit 50. In such a case, the insert pin 32 cannot be inserted into the sleeve 33. At this stage, when the sleeve 33 is rotated relative to the insert pin 32, the interference between the positioning pin 33h and the part of the claw unit 50 is eliminated at an angular position where the guide groove 32g and the positioning pin 33h are aligned. This allows the insert pin 32 to be inserted further into the sleeve 33.

[0053] When the insert pin 32 is inserted further, the inclined surfaces 51d of the locking claws 51b contact the inclined surface 33l on the inner periphery of the sleeve 33, causing the locking claws 51b to be displaced radially inward. Accordingly, during insertion of the insert pin 32, the claw unit 50 does not interfere with the sleeve 33, and the positioning pin 33h of the sleeve 33 is inserted while being guided by the guide groove 32g. As a result, relative rotation between the insert pin 32 and the sleeve 33 is restricted by the positioning pin 33h and the guide groove 32g.

[0054] When the insert pin 32 is inserted further into the sleeve 33, the stepped portion 32f of the insert pin 32 (see Fig. 2) contacts the inclined surface 33l of the sleeve 33, as shown in Fig. 6, thereby restricting further insertion. At this stage, the locking claws 51b of the claw unit 50 protrude in a direction perpendicular to the insertion direction. Accordingly, the locking claws 51b are engaged with the locking portion 33d of the sleeve 33 (see Fig. 7), so that the insert pin 32 is prevented from coming out of the sleeve 33.

[0055] In other words, the side roller 40 is fixed to the insert pin 32. In this manner, the side roller 40 can be attached to the chain 12 in one operation simply by pushing the side roller 40 onto the insert pin 32 of the chain 12 shown in Fig. 1.

[0056] <Use of the Chain 11 Including Side Rollers> As shown in Fig. 1, during use of the chain 11 including side rollers, the insert pins 32 move as the chain 12 moves, and the side rollers 40 roll in association with this movement. At this time, as shown in Fig. 5, the inner rings 41a of the ball bearings 41 are fixed to the insert pins 32 by the bolts 34 via the sleeves 33. The outer rings 41b of the ball bearings 41 are fixed to the rolling roller members 42. In this state, the rotational resistance of the ball bearings 41 themselves may increase due to wear, rust, entry of liquid or solid foreign matter, deterioration of lubricating oil, or the like. If this occurs, the rotational resistance of the ball bearings 41 may become greater than the frictional resistance between the insert pins 32 and the sleeves 33, causing slippage between the insert pins 32 and the sleeves 33. If such slippage occurs, the insert pins 32 and the sleeves 33 may be worn, deformed, or otherwise damaged. Accordingly, in the present embodiment, slippage between the insert pin 32 and the sleeve 33 is restricted by providing the positioning pins 33h, 33h on the sleeve 33 and inserting the insert pin 32 into the guide groove 32g.

[0057] <Removal of the Side Roller 40> A method for removing the side roller 40 from the insert pin 32 from the state shown in Fig. 6 will now be described. First, in order to remove the lid member 43 that seals the outer side, in the width direction Y, of the roller member 42 of the side roller 40, the retaining ring 43b (Fig. 4) that retains the lid member 43 is removed. The C-shaped retaining ring 43b is fitted in the retaining-ring receiving groove 42f formed in the inner periphery of the roller member 42 while being elastically urged to expand outward. The retaining ring 43b is flexed inward and removed from the roller member 42. The lid member 43 can then be removed.

[0058] When the lid member 43 is removed, the claw unit 50 is exposed. The locking claws 51b of the claw unit 50 are pushed into the support plate 52 with a tool or the like, thereby disengaging the locking claws 51b from the locking portion 33d. The side roller 40 can then be removed from the chain 12 by pulling the side roller 40 off the insert pin 32 while keeping the locking claws 51b disengaged.

[0059] When the lid member 43 is removed, the bolt 34 is exposed. The bolt 34 may then be removed using a tool. As a result, the claw unit 50 that fixes the insert pin 32 to the sleeve 33 is detached. The insert pin 32 can therefore be withdrawn from the sleeve 33. In other words, the side roller 40 can be removed from the chain 12. Then, by fixing the claw unit 50 again with the bolt 34, the side roller 40 can again be attached to the insert pin 32 in one operation.

[0060] (Advantages of the First Embodiment) (1-1) The attachment structure for the side roller 40 according to the present embodiment has the advantage that the side roller 40 can be firmly fixed while facilitating attachment of the side roller 40 to, and removal of the side roller 40 from, the moving member formed by the chain 12.

[0061] (1-2) The attachment structure for the side roller 40 according to the present embodiment includes the claw unit 50 provided at the distal end of the insert pin 32. The claw unit 50 includes the locking claws 51b that can protrude radially outward in a direction perpendicular to the insertion direction, that is, the width direction Y, in which the insert pin 32 is inserted into the sleeve 33. The sleeve 33 receives the locking claws 51b at the inner periphery of the sleeve 33 and allows the locking claws 51b to slide. The sleeve 33 includes the locking portion 33d with which the locking claws 51b of the insert pin 32 (the claw unit 50) are engaged.

[0062] Accordingly, by allowing the locking claws 51b of the claw members 51 to protrude at the locking portion 33d, the side roller 40 can be locked to the insert pin 32. When the locking claws 51b of the claw members 51 protrude at the locking portion 33d, an audible click is produced. This allows an operator to readily confirm from the click that attachment has been completed.

[0063] (1-3) The locking claws 51b are urged in the protruding direction, that is, radially outward, and are configured to be displaceable radially inward when the insert pin 32 is inserted into the sleeve 33. Accordingly, during insertion, the locking claws 51b are displaced radially inward, allowing the insert pin 32 to be smoothly inserted. When insertion is completed, the locking claws 51b protrude, thereby allowing the side roller 40 to be locked to the insert pin 32 in one operation.

[0064] (1-4) Each locking claw 51b has the shape of a claw including the inclined surface 51d, which slopes in the protruding direction from the leading end in the insertion direction, that is, the width direction Y, toward the proximal end of the insert pin 32. When the insert pin 32 is inserted, the inclined surface 51d contacts the inner peripheral surface 33k of the sleeve 33, thereby causing the locking claw 51b to be displaced radially inward. This configuration allows the locking claw 51b to move in the insertion direction along the inner peripheral surface 33k of the sleeve 33. Accordingly, when the insert pin 32 is inserted into the sleeve 33, the locking claw 51b does not hinder insertion, and after insertion, the sleeve 33 can be firmly fixed to the insert pin 32 by the locking claw 51b.

[0065] (1-5) The hollow cylindrical sleeve 33 includes the large-diameter portion 33a, forming the proximal portion in the insertion direction, the small-diameter portion 33b, forming the distal portion in the insertion direction, and the stepped portion 33c, connecting the large-diameter portion 33a and the small-diameter portion 33b by an inclined surface. In the large-diameter portion 33a, the locking claws 51b protrude radially but do not interfere with the sleeve 33. At the stepped portion 33c, the locking claws 51b are displaced radially inward as the insert pin 32 is inserted. In the small-diameter portion 33b, the locking claws 51b are maintained in a state of being displaced radially inward, and at the locking portion 33d, the locking claws 51b protrude radially outward and are engaged with the locking portion 33d. Accordingly, the insert pin 32 can be inserted partway into the sleeve 33 with little resistance and while remaining rotatable. At this stage, the guide groove 32g and the positioning pins 33h are readily aligned.

[0066] (1-6) A pair of claw members 51 are provided at positions on opposite sides of the central axis C of the insert pin 32, and the pair of claw members 51 are urged in the protruding direction by the springs 54. Accordingly, the locking claws 51b are constantly maintained in a protruding state.

[0067] (1-7) The claw unit 50 is provided at the distal end of the insert pin 32 in the insertion direction (the width direction Y). The attachment structure for the side roller 40 according to the present embodiment also includes the bolt 34 that detachably secures the claw unit 50 from the distal side. By removing the bolt 34, the side roller 40 can be removed from the insert pin 32.

[0068] (1-8) The insert pin 32 includes the guide groove 32g in the outer peripheral surface 32c of the insert pin 32, the guide groove 32g extending in the insertion direction. The positioning pins 33h, which slide relatively in the guide grooves 32g, are provided on the inner peripheral surface 33k of the sleeve 33. This restricts relative rotation between the insert pin 32 and the sleeve 33.

[0069] (1-9) The moving member is the chain 12. The insert pin 32 is coaxial with the chain pin 31 of the shaft member 30, and the chain pin 31 connects links of the chain 12. Accordingly, the side roller 40 can be arranged at an articulating portion of the chain 12, thereby providing the chain 11 including side rollers with smooth movement.

[0070] (1-10) The claw unit 50 includes the dish-shaped support plate 52 fixed to the distal end of the insert pin 32. The support plate 52 slidably holds the locking claws 51b of the pair of claw members 51 within the support plate 52. The springs 54 disposed between the pair of claw members 51 urge the pair of claw members 51 in the protruding direction, thereby causing the locking claws 51b of the claw members 51 to protrude into an engageable state. The support plate 52 allows the claw unit 50 to be configured as an integrated assembly.

[0071] <Second Embodiment> Next, a second embodiment, which is an example of another aspect of the present disclosure, will be described. The second embodiment differs from the first embodiment in the configuration for restricting relative rotation between the insert pin 32 and the sleeve 33. Description of configurations common to the first embodiment will be omitted.

[0072] Fig. 12 is a perspective view of the second embodiment. Fig. 13A is a front view of the insert pin 32 of the second embodiment as viewed in the Y direction. Fig. 13B is a crosssectional view taken along line XII(b)-XII(b) in Fig. 13A. Fig. 14A is a side view of a modified example of the sleeve 33 according to the second embodiment as viewed in the X direction. Fig. 14B is a cross-sectional view taken along line XIV(b)-XIV(b) in Fig. 14A.

[0073] In the first embodiment shown in Fig. 2, the insert pin 32 includes the guide groove 32g. In contrast, in the second embodiment shown in Figs. 12, 13A, and 13B, the insert pin 32 does not include the guide groove 32g. The other portions basically have the same configurations as the insert pin 32 and the claw unit 50 of the first embodiment.

[0074] Similarly, in the first embodiment shown in Fig. 2, the sleeve 33 includes the positioning pins 33h. In contrast, in the second embodiment shown in Figs. 12, 14A, and 14B, the sleeve 33 does not include the positioning pins 33h.

[0075] In contrast, as shown in Fig. 12, in the second embodiment, the sleeve 33 includes, in its inner peripheral surface, a guide groove 33m that is not provided in the first embodiment. The guide groove 33m is formed in the small-diameter portion 33b of the sleeve 33 and extends in the insertion direction of the sleeve 33. The width of the guide groove 33m is substantially equal to the width of the locking claw 51b of the claw unit 50, and the guide groove 33m guides the locking claw 51b with substantially no clearance within the guide groove 33m while allowing the locking claw 51b to slide in the insertion direction.

[0076] In addition, the sleeve 33 of the second embodiment includes a locking portion 33d‘, as in the sleeve 33 of the first embodiment. However, in the locking portion 33d of the first embodiment, the entire distal end surface of the sleeve 33 is formed as the flat locking portion 33d, as shown in Figs. 2 and 7. Accordingly, the locking claws 51b alone do not restrict relative rotation between the insert pin 32 and the sleeve 33.

[0077] In contrast, in the locking portion 33d‘ of the second embodiment, opposite sides extend toward the distal end to form rotation restricting portions 33j. Accordingly, the circumferential width of the locking portion 33 d’ of the second embodiment is formed to be substantially equal to the width of the locking claw 51b by the rotation restricting portions 33j on the opposite sides. In other words, the locking portion 33 d' of the second embodiment restricts rotation of the locking claw 51b about the central axis C by means of the rotation restricting portions 33j.

[0078] (Operation of the Second Embodiment) Referring to Fig. 12, when the insert pin 32 is inserted into the sleeve 33, the locking claws 51b of the claw unit 50 pass through the large-diameter portion 33a while remaining in a protruding state. When the insert pin 32 is inserted further, the locking claws 51b contact the stepped portion 33c. In this state, when the insert pin 32 is inserted still further, the locking claws 51b pass through the small-diameter portion 33b while being pushed inward by the stepped portion 33c. At this time, the insert pin 32 can be inserted even if each locking claw 51b is not angularly aligned with the corresponding guide groove 33m. If each locking claw 51b is angularly aligned with the corresponding guide groove 33m, the insert pin 32 may simply be inserted without relative rotation. If each locking claw 51b is not angularly aligned with the corresponding guide groove 33m, the insert pin 32 may be rotated relative to the sleeve 33. Then, when alignment is achieved, each locking claw 51b fits into the corresponding guide groove 33m.

[0079] (Modified Example) In the second embodiment shown in Fig. 12, the sleeve 33 includes the large-diameter portion 33a and the small-diameter portion 33b, as in the first embodiment. In contrast, as in a modified example shown in Fig. 14B, the stepped portion 33c may be omitted. In this case, when insertion is started, the insertion can be smoothly performed if each locking claw 51b is visually aligned in angular position with the corresponding guide groove 33m. Each locking claw 51b may also be angularly offset from the corresponding guide groove 33m. Even in such a case, if the insert pin 32 is rotated relative to the sleeve 33, each locking claw 51b fits into the corresponding guide groove 33m when the locking claw 51b becomes angularly aligned with the guide groove 33m.

[0080] In either case, if insertion is then continued, each locking claw 51b protrudes and is engaged with the locking portion 33d‘, thereby completing attachment of the side roller 40 to the insert pin 32. Even when each locking claw 51b is angularly offset from the corresponding guide groove 33m, insertion is still possible. However, if insertion is continued while the locking claw 51b remains offset, the locking claw 51b is not engaged with the locking portion 33 d'. As a result, the side roller 40 cannot be attached to the insert pin 32, and no click indicating engagement between the locking claw 51b and the locking portion 33d' is produced. This allows the operator to readily determine that attachment has not been completed.

[0081] (Advantages of the Second Embodiment) In addition to the advantages common to the first embodiment, the second embodiment has the following advantages.

[0082] (2-1) When the insert pin 32 is inserted into the side roller 40, the locking claw 51b of each claw member 51 attached to the distal end of the insert pin 32 is guided in the corresponding guide groove 33m of the sleeve 33. Accordingly, relative rotation between the insert pin 32 and the side roller 40 about the central axis C is suppressed.

[0083] (2-2) Each locking claw 51b of the claw unit 50 slides in the corresponding guide groove 33m of the sleeve 33 and, as insertion proceeds, is directly engaged with the locking portion 33d'. Accordingly, the side roller 40 can be readily attached to the insert pin 32.

[0084] (2-3) The locking claw 51b engaged with the locking portion 33d' has its circumferential movement restricted by the rotation restricting portions 33j, 33j provided on the opposite sides of the locking claw 51b in the circumferential direction. (2-4) Even when the locking claw 51b of each claw member 51 is not guided in the guide groove 33m of the sleeve 33, the locking claw 51b can be readily introduced into the guide groove 33m by rotating the sleeve 33 and the insert pin 32 relative to each other about the central axis C.

[0085] (2-5) Unlike the first embodiment, it is not necessary to form the positioning-pin holes 33i in the sleeve 33 or to fix the positioning pins 33h to the sleeve 33. Accordingly, the structure is simplified. <Modifications> The first embodiment and the second embodiment may be modified as follows.

[0086] - The first embodiment and the second embodiment may be implemented in any appropriate combination by a person skilled in the art to the extent that they are not inconsistent with each other. - In the above-described embodiments, a pair of claw members 51, 51 disposed at positions on opposite sides of the central axis C of the insert pin 32 are described as an example of a locking member of the present disclosure. However, the locking member is not limited to a pair of locking members, and may be a single locking member or three or more locking members. However, from the viewpoint of balance, an even number of locking members is preferable.

[0087] - The configuration for guiding insertion of the insert pin 32 into the sleeve 33 while restricting rotation between the insert pin 32 and the sleeve 33 is not limited to the guide groove 32g and the positioning pins 33h exemplified in the first embodiment, or to the guide groove 33m and the locking claw 51b exemplified in the second embodiment. For example, instead of a groove, the configuration may include a rib-shaped portion and a slider that slides along the rib-shaped portion.

[0088] - The locking claw 51b of the claw unit 50 is not limited to a tapered shape having a thin distal end, and may instead have a uniform thickness. In this case, the locking claw 51b can be pushed inward by providing the inclined surface 33l on the sleeve 33.

[0089] - If the locking claw 51b of the claw unit 50 has a tapered shape with a thin distal end, the locking claw 51b can be pushed inward even when a vertical step is provided instead of the inclined surface 33l of the sleeve 33.

[0090] - In the above-described embodiments, the elastic member of the present disclosure is exemplified by the spring 54 formed of a helical spring. However, the elastic member is not limited thereto, and a leaf spring may also be used. The locking claws 51b may also be urged using an elastic member such as rubber.

[0091] - In the above-described embodiments, the locking claws 51b are urged by the springs 54 so as to protrude, but the locking claws 51b do not necessarily need to be urged. For example, the locking claws 51b may be manually caused to protrude when the side roller 40 is positioned for attachment to the insert pin 32.

[0092] - Either one of the two ball bearings 41 may be omitted. Alternatively, three or more ball bearings 41 may be used. - The bearing of the present disclosure is not limited to any particular type. For example, a roller bearing may be used as the bearing instead of the ball bearing 41. Other types of bearings may also be used.

[0093] - The bolt 34 that fixes the claw unit 50 has been described as an example of a fixing means for detachably fixing the locking unit of the present disclosure from the distal side. However, the fixing means is not limited to the bolt 34, as long as the fixing means can detachably fix the locking unit from the distal side.

[0094] - The moving member of the present disclosure is not limited to the chain 12, and may be, for example, a belt conveyor, a tray for conveyance, a case for conveyance, or the like. - In the above-described embodiments, a configuration in which the side rollers 40 are provided on the opposite sides of the chain 12 has been described as an example. However, a configuration in which the side rollers 40 are provided only on one side may also be used.

[0095] - In the above-described embodiments, the shaft member 30 in which the chain pin 31 and the insert pin 32 are integrated has been described as an example. However, the chain pin 31 and the insert pin 32 may be configured as separate components. The drawings are schematic drawings for explaining the configurations of the above-described embodiments, and the number of components, shapes, dimensions, and the like depicted therein do not necessarily reflect actual forms.

[0096] - Numerical values, numerical ranges, shapes, materials, and the like relating to quantities, shapes, dimensions, and the like are merely examples and do not limit the present disclosure. Such matters may be appropriately optimized by a person skilled in the art. - Although metal components are used in the present disclosure, the type of metal is not limited. In addition, when the load is small, resin components may be employed. The roller member 42 may also be made of rubber or the like.

[0097] - The present disclosure may also be implemented by a person skilled in the art with configurations added, deleted, or modified, without departing from the scope of the claims.

Claims

1. A side-roller attachment structure, including a side roller rotatably supported by an insertion shaft having a circular cross section and projecting from a side portion of a moving member, whereinthe side roller includes:a roller member;a bearing that rotatably supports the roller member; anda hollow cylindrical sleeve attached to an inner peripheral side of the bearing,the side-roller attachment structure is configured to attach the roller member to the insertion shaft via the sleeve,the insertion shaft includes a locking unit including a locking member capable of protruding radially outward from the insertion shaft,the sleeve receives the locking unit on an inner periphery of the sleeve, allows the locking unit to slide, and includes a locking portion, andthe locking portion engages the locking unit.

2. The side-roller attachment structure according to claim 1, whereinthe locking member is urged in a protruding direction, andthe side-roller attachment structure is configured such that the locking member is displaceable radially inward when the insertion shaft is inserted into the sleeve.

3. The side-roller attachment structure according to claim 2, whereinthe locking member has a shape of a claw including an inclined surface that slopes in the protruding direction from a leading end in an insertion direction of the insertion shafttoward a proximal end of the insertion shaft, andthe inclined surface contacts and slides on an inner peripheral surface of the sleeve when the insertion shaft is inserted, so that the locking member is movable in the insertion direction of the insertion shaft along the inner peripheral surface of the sleeve.

4. The side-roller attachment structure according to claim 2, wherein the sleeve includes:a large-diameter portion forming a proximal portion in an insertion direction of the insertion shaft;a small-diameter portion forming a distal portion in the insertion direction; anda stepped portion that connects the large-diameter portion and the small-diameterportion by an inclined surface, andthe locking member is not displaced in the large-diameter portion, is displaced at the stepped portion as the insertion shaft is inserted, is maintained in a displaced state in the small-diameter portion, and protrudes to engage the locking portion.

5. The side-roller attachment structure according to claim 2, whereinthe locking member is one of a pair of locking members provided at positions onopposite sides of a central axis of the insertion shaft, andthe pair of locking members are urged in the protruding direction by an elastic member.

6. The side-roller attachment structure according to claim 2, whereinone of an outer peripheral surface of the insertion shaft and an inner peripheral surface of the sleeve includes a guide groove extending along an insertion direction of theinsertion shaft,the other of the outer peripheral surface of the insertion shaft and the inner peripheral surface of the sleeve is provided with a positioning pin, andthe positioning pin is movable relative to the guide groove within the guide groove.

7. The side-roller attachment structure according to claim 1, whereinthe sleeve includes a guide groove that guides the locking member in an insertion direction of the insertion shaft,the locking member protrudes into the locking portion to engage the locking portion when insertion of the insertion shaft is completed, andthe locking portion includes a rotation restricting portion that restricts rotation of the locking member about a central axis of the insertion shaft when the locking portion engages the locking member.

8. A chain with a side roller, including:the side roller according to any one of claims 1 to 7; anda chain as the moving member.

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