JP4942423B2 - Bearing structure for motorcycle wheels - Google Patents

Description

The present invention relates to a bearing structure for a two-wheeled vehicle wheel, and particularly to a structure that eliminates an increase in bearing friction caused by tightening a collar.

A wheel is arranged between a pair of left and right forks, the axle supported by the left and right forks is passed through the axle hole provided in the hub of the wheel, and the axle is supported by bearings provided at the left and right ends of the axle hole, 2. Description of the Related Art A two-wheeled vehicle wheel bearing structure is known in which left and right bearings are positioned by a distance collar fitted around an axle (see Patent Document 1).
In addition, there is a structure in which the axle has a stepped structure, and bearings having different diameters are arranged directly on the axle (see Patent Document 2).
Furthermore, there is a structure that uses an angular bearing to adjust the pressure between the bearings.
JP 2005-225289 A Japanese Examined Patent Publication No. 4-72721

By the way, when positioning the bearings provided on the left and right of the hub axle hole with a distance collar, when the end of the axle is fastened with a high axial force, the distance collar bends between the left and right bearings, and this reaction force causes the inner race of the bearing to bend. By tightening, the friction during wheel rotation may be increased. In order to prevent such bending of the distance collar, it is conceivable to use a material having a high Young's modulus and a large cross-sectional area. However, if this is done, the weight will increase. A structure that does not increase is desired.
Further, when an angular bearing is used, it takes time to adjust the pressurization, and it is necessary to adjust the pressure every time it is tightened.
The present application aims to realize such a request.

In order to solve the above-mentioned problems, the invention according to claim 1 relating to a bearing structure for a two-wheeled vehicle wheel is characterized in that an axle member supported at both ends in the longitudinal direction between a pair of left and right forks sandwiching the wheel is used as a wheel hub. Let it pass through the axle hole
In a bearing structure for a two-wheeled vehicle wheel in which the hub is rotatably supported around the axle by bearings provided at both ends in the longitudinal direction of the axle hole, and one end of the axle member is fastened and fixed to the fork. ,
The axle member is configured with an axle having a uniform outer diameter, and a stepped collar formed in a stepped shape that is fitted to the periphery thereof and changes in outer diameter in a stepped manner toward one end side.
The bearing is a combination of ball bearings having the same outer diameter but relatively different inner diameters,
Two small ball bearings having a larger inner diameter are provided, and the inner race of the small ball bearing is fitted onto the large diameter portion of the stepped collar by penetrating the large diameter portion of the stepped collar ,
A large ball bearing with a smaller inner diameter is brought into contact with one end of the stepped collar on the narrow diameter side,
The inner race of the large ball bearing is fixed between one end of the stepped collar on the narrow diameter side and a collar interposed on the opposite side across the large ball bearing ,
A driven sprocket is attached to the outside of the small diameter ball bearing disposed on the large diameter portion side of the stepped collar in the axle direction .

Invention of Claim 2 is the said Claim 1 WHEREIN: The other end part on the opposite side to the front-end | tip part which positions the said large ball bearing among the longitudinal direction both ends of the said stepped collar penetrates the said small ball bearing. The collar is positioned by the collar, and the collar is positioned by the hub.

In the invention the above claim 1 or 2 of claim 3, of the bearing provided in the axial end side of the axle, the driving force is the inner race is in contact with the inner race of the miniature ball bearing side to be transmitted A connecting member for rotating the inner race integrally with the stepped collar is provided between the outer peripheral surface of the stepped collar .

In the invention the above third aspect of claim 4, wherein said connecting member is a O-ring attached to the outer peripheral surface of the front collar with Kidan.

According to the invention of claim 1, the axle member is formed in a stepped shape whose outer diameter changes stepwise toward one end side, and the bearing is a combination of ball bearings having relatively different inner diameters. The bearing having the larger inner diameter at the large diameter portion is supported by penetration, and the bearing having the smaller inner diameter is supported by penetration at the small diameter portion of the axle member. Further, the inner race of the bearing having the smaller inner diameter was fixed between the step portion provided on the axle member and the collar interposed on the opposite side (fork side) across the bearing. For this reason, even if the shaft end of the axle member is fastened, it is not necessary to clamp a long collar close to the length of the axle hole between the bearings, and a relatively short collar on the fork side is sufficient. Therefore, even if a large axial force is applied, the collar will not bend and the inner race will not be tightened, so an increase in friction can be avoided.
Moreover, it is not necessary to form the collar with a special material or to make it thick so that an increase in weight can be prevented. In addition, since it does not take time and effort to adjust the pressure in the angular bearing, assembly work is facilitated.

In addition, since the stepped axle member is composed of an axle having a uniform outer diameter and a stepped collar fitted around the axle, the stepped portion only needs to be formed in the collar portion. It becomes easy. Moreover, the axle can be shared between different models. Further, since the tip end portion of the stepped collar can be used for positioning the inner race, the positioning portion can be easily formed.

According to the invention of claim 2 , the end portion of the stepped collar that penetrates the bearing having a large inner diameter on the large-diameter portion side is positioned by the collar interposed from the outside without positioning the inner race. In addition, since the collar is positioned by the hub, the axial force at the time of tightening does not reach the stepped collar and the bearing supported on the large diameter portion, so that the bearing and the stepped collar are not tightened. .

According to the invention of claim 3 , among the bearings provided on the both axial ends of the axle member or the stepped collar, the inner race of the bearing on the side to which the driving force is transmitted and the axle member or step where the inner race contacts. A connecting member is provided between the outer collar and the outer race so that the inner race rotates together with the axle. Since the inner race is connected to the outer peripheral surface of the outer peripheral surface and tries to rotate integrally, the inner race does not slide on the outer peripheral surface of the axle member or the stepped collar, and wear of the inner race and the axle member or the stepped collar can be prevented. .

According to the invention of claim 4 , since the connecting member is an O-ring attached to the outer peripheral surface of the axle member or the stepped collar, the structure of the connecting member is simplified.

  An embodiment will be described below with reference to the drawings. In the present application, the front / rear, left / right, up / down, inside / outside directions are based on the vehicle body. In addition, the above-described directions of the vehicle body components are based on the vehicle body mounting state.

FIG. 1 shows a right side surface of a downhill bike to which a wheel bearing structure according to an embodiment is applied. A downhill bike is a downhill competition bicycle that descends a hill slope and competes for running time, and is an example of a two-wheeled vehicle.
This downhill bike supports a pair of left and right front forks 3 rotatably with respect to a head pipe 2 provided at the front end of a vehicle body frame 1 and via a front wheel axle 4 spanned between the lower ends of the front forks 3. The front wheel 5 is rotatably supported. Although not shown, a bearing is interposed between the front wheel axle 4 and the hub of the front wheel 5.

The vehicle body frame 1 has a loop shape including a main portion 6, a front down portion 7, a rear down portion 8, and a lower portion 9. The front end portion of the rear fork 11 is swingable up and down via a pivot shaft 10 in the rear down portion 8. Is supported by the rear cushion 12 and is cushioned by the rear cushion 12.
The pivot shaft 10 is inclined downward while projecting upward and extends rearward, and a rear wheel 14 is rotatably supported at the rear end via a rear wheel axle 13.

  A driven sprocket 15 is coaxially provided on a hub (described later) of the rear wheel 14 that rotates about the axle 13, and is driven to rotate by a drive sprocket 17 via a chain 16. The drive sprocket 17 is provided on the side surface of the case of the transmission 18 and is connected to the output shaft inside the transmission 18.

The transmission 18 accommodates an input shaft, an output shaft, and multi-stage transmission sprockets having different numbers of teeth, so that the pedaling force of the input shaft is shifted and transmitted to the output shaft via the selected stage transmission sprocket. It is the well-known thing comprised by.
In the figure, reference numeral 14 a denotes a tire, and 14 b denotes a rim, which respectively constitute the rear wheel 14. A tensioner 21 includes a tension roller. Reference numeral 22 denotes a saddle, which is supported by the rear down portion 8 via a saddle frame 23. Reference numeral 24 denotes a bar handle.

  FIG. 2 is a cross-sectional view along the axial direction of the axle 13 showing the bearing structure of the axle 13 in the rear wheel. The rear wheel 14 includes a hub 25 and a spoke 26 in addition to the tire 14 a and the rim 14 b (FIG. 1), and an axle hole 27 passes through the center of the hub 25 to the left and right.

On both left and right ends of the axle hole 27, bearing housing portions 28 and 29 having an enlarged diameter are provided. The inner diameters of both bearing housing portions 28 and 29 are the same.
A large ball bearing 30 is fitted in the left bearing housing portion 28. The large ball bearing 30 includes an outer race 31, a ball 32, and an inner race 33. The outer race 31 is press-fitted into the bearing housing portion 28, and the inside is positioned by the step portion 28 a of the axle hole 27.

  Two small ball bearings 35, 35 spaced apart from each other by a predetermined distance are juxtaposed in the right bearing housing portion 29. The small ball bearing 35 also includes an outer race 36, a ball 37, and an inner race 38. The outer diameters of the large ball bearing 30 and the small ball bearing 35 are the same, but if the inner diameters, that is, the inner diameters of the inner races 33 and 38 are D1 and D2, the inner diameter of the small ball bearing 38 is larger ( As a result, each small ball bearing 35 is smaller than the large ball bearing 30.

  A step distance collar 40 is passed inside the inner race 38 of the small ball bearing 35, and the inner race 38 of each small ball bearing 35 is in direct contact with the large diameter step portion 41 which is the end portion on the large diameter side. . The outer diameter of the large diameter step portion 41 is substantially the same as the inner diameter D2 of the inner race 38. The step distance collar 40 is hollow, and the inner diameter of the penetrating shaft hole 42 is uniform and equal to D1.

  The stepped distance collar 40 is fitted to the outer periphery of the axle 13 and has a length slightly shorter than the length of the axle hole 27 (equivalent to the length of the left bearing housing portion 28). One end is positioned in contact with the inner side surface of the inner race 33. The other end portion on the large diameter side, which is the large diameter step portion 41 side, extends further outward than the outer one of the pair of small ball bearings 35 and is located in the vicinity of the outer end portion of the right bearing housing portion 29. is doing.

A shaft portion 43a of a flanged collar 43 is fitted to the outside of the large ball bearing 30 in the left bearing housing portion 28, its end abuts against the outer surface of the inner race 33 , and the flange portion 43b is connected to the rear fork. 11 is in contact with the inner surface of the left side portion. When the axle 13 is tightened, the shaft portion 43a of the collar 43 presses the outer surface of the inner race 33. However, as described later, a large axial force is not applied to the stepped distance collar 40 that contacts the inner surface. The force to tighten up is not applied. In addition, since the shaft portion 43a of the flanged collar 43 is relatively short and relatively thick, and the inner race 33 is also relatively thick, it is difficult for these deflections to occur during fastening.

A flanged collar 44 is fitted onto the large-diameter step portion 41 on the outer side of the outer small ball bearing 35 of the pair of small ball bearings. The flange 44 b of the flanged collar 44 abuts on the outer surfaces of the outer race 36 and the inner race 38, and the shaft portion 44 a abuts on the side surface of another collar 45. The inner diameter of the collar 45 is the same as the inner diameter of the large-diameter step portion 41, and the shaft end portion of the large-diameter step portion 41 contacts the inner surface of the collar 45 in the same manner as the shaft portion 44a. The outer surface of the collar 45 abuts against the inner surface of the right portion of the rear fork 11.

  Although not shown, the axle 13 has a bolt shape, one end is a head, the other end is threaded, the left and right rear forks 11 and 11 are penetrated, and an intermediate portion is a flange. The inner collar 43, the large ball bearing 30, the stepped distance collar 40, the flanged collar 44, and the collar 45 are passed through the respective inner sides, and the screws on the other end side are fastened with nuts. The hub 25 is supported by a bearing via the axle 13.

The right end of the hub 25 constitutes a power transmission portion, and the driven sprocket 15 is coupled to the outer peripheral portion of the right bearing housing portion 29 via a one-way clutch 46. The wall thickness center line L of the driven sprocket 15 is an outer small ball. It arrange | positions so that the center in the bearing 35 may be passed.
When the driving force is transmitted from the driven sprocket 15 side, the hub 25 is rotated in the forward direction integrally. When the hub 25 is rotated in the reverse direction, the hub 25 is freely rotated in the reverse direction by cutting off the coupling with the driven sprocket 15. Reference numeral 47 is a retainer for the driven sprocket 15 and reference numeral 48 is an O-ring as a seal.

FIG. 3 is an enlarged sectional view showing the bearing structure of the small ball bearing 35.
The collar 45 is positioned by contacting the outer peripheral portion of the inner surface with a stepped portion 29b formed in the right bearing housing portion 29. In this state, the end portion of the shaft portion 44a of the flanged collar 44 and the stepped distance collar 40 are simultaneously provided. The right side end portion 40b is positioned. However, since the collar 45 is positioned on the stepped portion 29b, a large axial force is not applied from the flanged collar 44 to the small ball bearings 35 and 35 even when the axle 13 is tightened.

A space collar 49 is disposed between the outer races 36, 36 of the pair of small ball bearings 35, 35, and the distance between the two is kept at a predetermined value.
A connecting member 50 is interposed between the small ball bearings 35 and 35. The connecting member 50 includes an inner peripheral surface 53 having a width that is the same as or slightly larger than the inner side surface 51, the outer side surface 52, and the space collar 49. It is wound so as to be in close contact with the outer surface of 41.

  The connecting member 50 is made of a material that is rich in elasticity, such as rubber, and can form a large frictional force at the contact portion. However, not only rubber but various elastic members such as a metal spring are possible. The length of the inner side surface 51 and the outer side surface 52 protruding outward in the radial direction is longer on the inner side surface 51, and the tip reaches the vicinity of the outer race 36. On the other hand, the outer side surface 52 overlaps the side surface of the inner race 38.

Next, the operation of this embodiment will be described. As shown in FIG. 2, a large ball bearing 30 is fitted in the left bearing housing portion 28 of the hub 25, and a pair of small ball bearings 35 are fitted in the right bearing housing portion 29. At this time, the space collar 49 and the connecting member 50 are interposed between the small ball bearings 35 and 35.

  Further, the stepped distance collar 40 is inserted from the small ball bearing 35 side into the inner race 38 and the tip 40 a is brought into contact with the inner side surface of the inner race 33 of the large ball bearing 30. Subsequently, among the pair of small ball bearings, the collar 44 with the flange is fitted from the outside to the small ball bearing 35 on the outside, and the collar 45 is arranged outside the collar 44 with the flange. The axle 13 is fixed by fastening the screw part provided at one end of the axle 13 with a nut through the axle 13 having one rear fork 11 penetrated to the inside of the bearing and the other end to the other rear fork 11. Then, the rear wheel hub 25 is rotatably supported on the axle 13.

  At this time, one end portion 40a on the small diameter side of the stepped distance collar 40 abuts on the inner surface of the inner race 33 of the large ball bearing 30, but the axial force from the right side during tightening causes the collar 45 to move to the step portion 29b. Since it is positioned, a force larger than necessary is not applied, and no bending occurs.

  The axial force from the left side is transmitted from the shaft portion 43 a of the flanged collar 43 to the inner race 33, but the positioning of the large ball bearing 30 is performed by the outer race 31 and the step portion 29 a, and the inner race 33 is stepped. Since almost no force is applied from the one end portion 40a of the distance collar 40, the shaft portion 43a of the flanged collar 43 is not bent or the inner race 33 is not tightened by the axial force from the left side. For this reason, the increase in the friction of the large ball bearing 30 due to the fastening of the axle 13 can be prevented.

  Moreover, it is not necessary to form the stepped distance collar 40, the flanged collars 43 and 44, the collar 45, etc. from a special material or to make them thick so that an increase in weight can be prevented. In addition, since it does not take time and effort to adjust the pressure in the angular bearing, assembly work is facilitated.

  In addition, since the stepped axle member is composed of the axle 13 having a uniform outer diameter and the stepped distance collar 40 fitted to the periphery thereof, the stepped portion may be formed only in the collar portion. Manufacturing becomes easy. Moreover, the axle 13 can be shared between different models. Further, since the tip end portion 40a of the stepped distance collar 40 can be used for positioning the inner race, the positioning portion can be easily formed.

  As shown in FIG. 3, in the right bearing housing portion 29, the small ball bearings 35 and 35 are positioned on the large diameter step portion 41, and the collar 45 is positioned by the step portion 29b. Since the axial force is transmitted from the collar 45 to the hub 25 side and is not applied to the other end portion 40b of the stepped distance collar 40 or the flanged collar 44, the small ball bearings 35 and 35 are not tightened. Prevent increase.

  When the small ball bearings 35 and 35 are positioned and fixed in the right bearing housing 29 with the connecting member 50 interposed therebetween, the space between the small ball bearings 35 and 35 is accurately positioned by the space collar 49 and the flanged collar 44. Therefore, the inner surface 51 of the connecting member 50 is in close contact with the outer surface of the inner race 38 in the inner small ball bearing 35, and the outer surface 52 is in close contact with the inner surface of the inner race 38 in the outer small ball bearing 35.

  At this time, since the inner peripheral surface 53 of the connecting member 50 is also in close contact with the outer peripheral surface of the large-diameter stepped portion 41 at the same time, a force in a state where thrust force, twisting force, bending force, and the like are combined in a complex manner with the hub 25. By joining the small ball bearings 35, 35, the connecting member 50 prevents the inner race 38 from sliding on the large-diameter step portion 41, and the inner race 38 and the large-diameter step portion 41 are integrally connected. To do. For this reason, wear due to the inner race 38 sliding on the large-diameter step portion 41 can be prevented.

FIG. 4 is a view corresponding to FIG. 3 relating to another embodiment of the connecting member 50. In this figure, only the connecting member 50 is changed, and the others are not changed. Therefore, the same reference numerals are used for the other parts, and the duplicate description is omitted.
In this example, the connecting member 50 is composed of an O-ring 60. This O-ring is provided with an annular groove 61 in the portion of the large-diameter step portion 41 where each inner race 38 abuts, and the O-ring 60 is fitted into the annular groove 61 so that a part protrudes to the outer surface. Keep together.

  When the large-diameter step portion 41 is fitted to the inner circumference of the inner race 38 of the small ball bearing 35 in this state, the protruding portion of the O-ring 60 is elastically deformed by the inner race 38 and retreats into the annular groove 61. The inner race 38 and the large-diameter step portion 41 are joined together in close contact with the inner peripheral surface 38 to prevent the inner race 38 from sliding.

  In this case, the inner ring 38 and the outer peripheral surface of the large-diameter step portion 41 are directly coupled by the O-ring 60 so that the inner race 38 does not need to be closely attached to the side surface. It will be easy. In addition, since it is possible to use commercially available standard products, the overall cost can be reduced.

The present invention is not limited to the above-described embodiments, and various modifications and applications can be made within the principle of the invention. For example, an axle member in which the axle 13 and the stepped distance collar 40 are integrated may be used. In this axle member, a substantial part of the stepped distance collar 40 changes along the outer shape of the stepped distance collar 40, and the outer diameter changes stepwise so that the left side from the tip 40a becomes the outer shape of the axle 13. Is. In this way, the number of parts can be reduced.
Further, the present invention can be applied not only to downhill bikes but also to various pedal force type motorcycles and motorcycles. Further, the present invention can be applied to a front wheel axle support structure.

Side view of a downhill bike to which the present invention is applied according to an embodiment Sectional view showing the bearing part of the rear wheel axle Sectional view showing an enlarged part of the shaft bearing part The figure equivalent to FIG. 3 regarding another Example of a connection member

Explanation of symbols

1: body frame, 2: head pipe, 5: front wheel, 11: rear fork, 13: rear wheel, 15: driven sprocket, 25: hub, 30: large ball bearing, 33: inner race, 35: small ball bearing, 38: inner race, 40: stepped distance collar, 41: large diameter step, 43: flanged collar, 44: flanged collar, 45: collar, 49: space collar, 50: connecting member

Claims (4)

An axle member (13, 40) supported at both ends in the longitudinal direction between a pair of left and right forks sandwiching the wheel is passed through an axle hole provided in the hub (25) of the wheel,
In a bearing structure for a two-wheeled vehicle wheel in which the hub is rotatably supported around the axle by bearings provided at both ends in the longitudinal direction of the axle hole, and one end of the axle member is fastened and fixed to the fork. ,
The axle member has a stepped collar (13) having a uniform outer diameter and a stepped collar (fitting to the periphery thereof, and having a stepped shape in which the outer diameter changes stepwise toward one end. 40)
The bearing is a combination of ball bearings having the same outer diameter but relatively different inner diameters,
Two small ball bearings (35) having a larger inner diameter are provided, and the inner race (38) of the small ball bearing (35) is formed by passing the large diameter portion (41) of the stepped collar (40). Fit on the large diameter part (41) of the stepped collar (40) ,
A larger ball bearing (30) having a smaller inner diameter is brought into contact with one end (40a) on the narrow diameter side of the stepped collar (40) ;
The inner race (33) of the large ball bearing (30) is interposed on one side (40a) on the narrow diameter side of the stepped collar (40) and the opposite side across the large ball bearing (30). that is fixed between the collar (43),
A driven sprocket (15) is attached to the outside of the small-diameter ball bearing (35) disposed on the large-diameter portion (41) side of the stepped collar (40) in the axle direction. Bearing structure of wheel for wheels. Of the both ends in the length direction of the stepped collar (40) , the other end (40b) opposite to the tip (40a) for positioning the large ball bearing (30 ) is the small ball bearing (35). The bearing structure for a wheel for a two-wheel vehicle according to claim 1 , wherein the collar (45) is positioned by the collar (45) , and the collar (45) is positioned by the hub (25) . Of the bearings provided on both axial end sides of the axle, the outer periphery of the inner race (38) and collar with the stage the inner race from contacting the side of the small ball bearings driving force is transmitted (35) (40) between the surface and the inner race (38) set forth in claim 1 or 2, characterized in that a connecting member for rotating (50) integral with the color with the step (40) 2 Bearing structure of wheel for wheels. Bearing structure for motorcycle wheels according to claim 3, characterized in that the O-ring attached to the outer peripheral surface (60) of the connecting member (50) color to front Kidan (40).

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