JPH061178U - Bearing structure of bicycle crankshaft - Google Patents

Abstract

(57) [Summary] (Correction) [Purpose] The bearing structure can be easily integrated into a single unit, and rotation adjustment (ball bearing adjustment) can be performed to simplify the assembly work. [Structure] A crankshaft 3 in which flanges 1 and 2 are integrally formed at left and right spaced positions, and shaft outer peripheral portions are connected by concave curved outer surfaces 4 and 5, and a retainer disposed on the concave curved outer surface 5 on the side A of the chain sprocket. One-side ball bearing 1 held by
0, a first fixed nut 12 having a concavely curved inner surface 11 for rollingly holding it formed on the inner periphery, and an anti-chain sprocket side B
The other side ball bearing 15 disposed on the concave curved outer surface 4 and held by the outer race 14, and the first fixing nut 1.
2 has one side screw part 17a screwed into the inner end side screw hole 12b and the other side screw hole 17b screwed into the screw part 14a,
The connecting pipe 17 is provided so that its position can be adjusted, the lock nut 16 for variably adjusting the connecting position, and the second fixing nut 18 provided on the outer peripheral side and the outer end side.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a bearing structure for a crankshaft for a bicycle, in which cranks each having a pedal of a bicycle disposed at its tip end are attached to both left and right ends.

[0002]

[Prior art]

 BACKGROUND ART Conventionally, as a bearing structure for a bicycle crankshaft of the above-mentioned example, there is a structure described in, for example, Japanese Utility Model Publication No. 3-14469. That is, a flange portion is integrally formed at the left and right separated positions, and the crankshaft is formed by connecting the flange portion and the shaft outer peripheral portion with concave outer surfaces, and the outer races provided on the left and right concave outer surfaces of the crankshaft. A crankshaft for a bicycle equipped with small-diameter ball bearings on the side of the chain sprocket and the side opposite to the chain sprocket to be held, and left and right fixed nuts arranged on the outer peripheral side and the outer end side of the left and right outer races, respectively. Bearing structure.

However, the above conventional structure has the following problems. In other words, the rotation adjustment (ball contact adjustment) can be performed only by tightening the left and right fixing nuts with the entire bicycle crankshaft bearing structure mounted on the bicycle hanger pipe. However, rotation adjustment cannot be performed when the bearing structure itself is sub-assembled. Therefore, it is necessary to perform a skilled work to assemble the above-mentioned bearing structure on the hanger pipe of the bicycle and perform the rotation adjustment. There was a necessary problem.

[0004]

[Problems to be solved by the device]

 According to this invention, the bearing structure can be easily integrated into a unit, and rotation adjustment (ball bearing adjustment) can be performed in the unitized structure itself, and the unitized structure is assembled to a bicycle hanger pipe. The purpose of the present invention is to provide a bicycle crankshaft bearing structure that can be easily assembled without requiring any skilled work.

[0005]

[Means for Solving the Problems]

 According to this invention, a flange portion is integrally formed at left and right positions, and a crankshaft in which the flange portion and the shaft outer peripheral portion are connected by a concave curved outer surface and a concave curved outer surface on the chain sprocket side of the crankshaft are arranged. One side ball bearing that is installed and retained by a retainer, a first fixing nut that has a concave curved inner surface that holds the one side ball bearing rotatably on the inner circumference, and a concave portion on the side opposite to the chain sprocket side of the crankshaft. The other side ball bearing that is disposed on the outer surface of the curve and is held by the outer race, the one side screw part that is screwed into the inner end side screw hole of the first fixing nut, and the inner end side screw part that is screwed into the outer race. A connecting pipe having a screw hole on the other side for adjusting the position between the first fixing nut and the outer race, and the connecting part screwed to the screw portion of the outer race. And a second fixing nut disposed on the outer peripheral side and the outer end side of the outer race, and a bearing structure for a bicycle crankshaft. .

[0006]

[Effect of device]

 According to the present invention, the one side ball bearing held by the retainer is installed inside the concave curved inner surface of the first fixing nut, and the connecting pipe is screwed into the inner end side screw hole of the first fixing nut while the inner end is being screwed. The other side ball bearing is installed in the outer race where the lock nut is arranged on the side screw part, and the other side ball bearing is placed so that the other side ball bearing is located on the left curved outer surface of the crankshaft. After being inserted into the bearing, the connecting pipe and the first fixing nut are integrally mounted on the crank shaft from one end of the crank shaft, and the first fixing nut and the connecting pipe are rotated integrally. By operating and screwing the other threaded hole of the connecting pipe into the threaded part of the outer race, these elements (crankshaft, ball bearings, 1st fixed nut, outer race, lock nut) are connected. Simply be integrally unitized.

In addition, in the structure integrally formed as described above, when the first fixing nut and the connecting pipe are integrally rotated with respect to the screw portion of the outer race, the one-side ball bearing, Rotation adjustment (ball bearing adjustment) between the left and right ball bearings can be performed via the concave curved outer surface on the side, the crankshaft, and the concave curved outer surface on the other side, and after the adjustment operation is completed, rotate the lock nut, By pressing the inner surface of the lock nut against the other end surface of the connecting pipe, it is possible to maintain the rotation adjustment completed state (a state in which proper ball bearing adjustment is maintained).

Therefore, there is an effect that the bearing structure can be easily integrated into a unit, and further, rotation adjustment (ball bearing adjustment) can be performed in the unitized structure itself, and the unitized structure can be used as a bicycle. There is an effect that it is possible to easily assemble even hanger pipes without requiring any skilled work when they are assembled to the hanger pipe.

[0009]

【Example】

 An embodiment of the present invention will be described in detail below with reference to the drawings. The drawings show the bearing structure of a bicycle crankshaft. In FIGS. 1 and 2, a metal crankshaft 3 integrally formed with flanges 1 and 2 having circular cross sections is provided at left and right positions. The outsides of the above-mentioned flanges 1 and 2 and the outer peripheral portion of the shaft are integrally connected by concave curved outer surfaces 4 and 5, respectively.

A plurality of flattened portions 6 are formed at the left and right ends of the crankshaft 3 for fitting a base portion of a crank (not shown) having a bicycle pedal at the tip thereof. The left and right ends of the crankshaft 3 are formed into a substantially rectangular cross section, and the left and right ends of the crankshaft 3 are integrally formed with screw parts 7 and 8 for mounting the crank. Instead of the screw parts 7 and 8 described above, a crank mounting screw hole may be formed inward from the shaft end of the crankshaft 3 where the flat part 6 is formed.

As shown in FIG. 3, the concave curved outer surface 5 of the crankshaft 3 on the chain sprocket side A (driving side) has a plurality of one-sided balls held by a retainer 9 made of metal or synthetic resin. A bearing 10 is provided, and a first fixed nut 12 having a concave curved inner surface 11 that holds the one-side ball bearing 10 rotatably is provided on the inner circumference.

As shown in an enlarged view in FIG. 4, the first fixing nut 12 is integrally formed with a threaded portion 13 on the outer periphery, and in this embodiment, the maximum diameter portion (11max) on the concave curved inner surface 11 is the first fixing nut. 12 is formed in a retaining groove structure (that is, a step structure) whose diameter is set to be larger by a predetermined amount L than the inner diameter of the annular surface 12a of the inner circumference 12, but the above step L is not always necessary. Absent. Further, a screw hole 12b is screwed on the inner end side of the above-mentioned annular surface 12a.

On the other hand, the other side ball bearing 15 held by the outer race 14 is disposed on the concave curved outer surface 4 of the crankshaft 3 on the side B opposite to the chain sprocket. Here, the other side ball bearing 15 is also held by a retainer (not shown) like the one side ball bearing 10. A screw portion 14a is screwed on the inner end side of the outer race 14 described above, and a first lock nut 16 is screwed onto the screw portion 14a.

A connecting pipe 17 is arranged between the screw portion 14 a of the outer race 14 and the screw hole 12 b of the first fixing nut 12 described above. In this embodiment, a resin pipe is used as the above-mentioned connecting pipe 17 for the purpose of reducing the weight, but it may be a metal pipe, an aluminum pipe, an aluminum alloy pipe or the like. A threaded portion 17a that is screwed into the screw hole 12b of the first fixing nut 12 is screwed on the outer periphery of the right end of the connecting pipe 17, and a screw portion 14a of the outer race 14 is screwed on the inner periphery of the left end. The other side screw hole 17b is screwed.

By the way, a second fixing nut 18 arranged on the outer peripheral side and the outer end side of the outer race 14 is provided, and a screw portion 18a is formed on the outer peripheral portion of the second fixing nut 18.

Screw holes 20 and 21 are formed in the inner peripheral portions on the left and right ends of the bicycle-side hanger pipe 19 into which the first and second fixing nuts 12 and 18 are respectively screwed. . Reference numeral 22 in the drawing is a second lock nut that is screwed into the threaded portion 18a of the second fixing nut 18, and the second lock nut 22 has a plurality of engagements for locking a fastening jig as shown in FIG. Although the concave portion 22a is formed, the attachment of the second lock nut 22 itself can be omitted.

Further, at the inner peripheral portion of the above-mentioned first fixed nut 12 on the outer end side of the one side ball bearing 10, a sealing member 23 for sealing between the inner peripheral portion and the outer peripheral portion of the crankshaft 3 is provided. Is installed.

Further, a seal member 24 that seals between the inner peripheral portion and the outer peripheral portion of the crankshaft 3 is attached to the inner peripheral portion of the outer race 14 on the outer end side of the other side ball bearing 15. There is.

The bearing structure of the bicycle crankshaft having the above-described structure has the elements 3, 10 under the condition before being attached to the hanger pipe 19 on the bicycle side in FIG. 2 (the condition in which the hanger pipe 19 is removed in FIG. 2). , 12, 14, 15, 16, 17, 23, 24, 18, 22 are integrated into a unit.

That is, in order to make the above-described bearing structure of the bicycle crankshaft into an integral unit as shown in FIG. 6 through the state of FIG. 5, first, with respect to the concave curved inner surface 11 of the first fixing nut 12, The one side ball bearing 10 held by the retainer 9 is inserted from the left side of FIG. Since the above-mentioned one-side ball bearing 10 is held so as to be rotatable with respect to the retainer 9 and capable of a slight vertical movement, it can be easily inserted into the concave curved inner surface 11 beyond the step L. .

Next, the one side screw portion 17a of the connecting pipe 17 is screwed into the screw hole 12b of the first fixing nut 12 described above, and as shown in FIG. On the other hand, the other side ball bearing 15 is arranged with respect to the outer race 14 in which the lock nut 16 is screwed in advance on the screw part 14a, and the crankshaft 3 is inserted into the other side ball bearing 15 from the right side of the outer race 14. After inserting and penetrating, locating the ball bearing 15 on the other side on the concave curved outer surface 4 and inserting a grease into a predetermined inner diameter portion of the outer race 14, a seal member 24 is integrally attached to the outer race 14, As shown in FIG. 5, an assembly sub-assembly U2 on the other side is formed.

Next, the assembly sub-assembly U1 on one side shown in FIG. 5 is mounted on the crank shaft 3 from the right end of the crank shaft 3 in the assembly sub-assembly U2 on the other side, and the assembly sub-assembly 1 on one side is formed. The body U 1 is integrally rotated to screw the other side screw hole 17b of the connecting pipe 17 into the screw portion 14a of the outer race 14 of the assembly side structural body U2 on the other side, and as shown in FIG. The elements 3, 10, 12, 14, 15, 16, 17, and 24 are integrated, and further, after the grease is inserted into the predetermined inner diameter portion of the first fixed nut 12 described above, the seal member 23 is attached to the first fixed nut 12. Are integrally attached to form a unit body U 3 as shown in FIG.

In this way, in the unit body U3 in which the above-mentioned respective elements 3, 10, 12, 14, 15, 16, 17, 23, 24 are integrated, with respect to the screw portion 14a of the outer race 14. The first fixing nut 12 and the connecting pipe 17 are integrally rotated, and the ball on the other side is passed through the one side ball bearing 10, the concave curved outer surface 5 on the same side, the crankshaft 3, and the concave curved outer surface 4 on the other side. Adjusting force is applied to the bearing 15 to perform rotation adjustment (ball bearing adjustment) between the left and right ball bearings 15 and 10, and after the adjustment operation is completed, the first lock nut 16 is rotated to When the right side surface of the first lock nut 16 is pressed against the left side end surface of the connecting pipe 17, it can be held under a rotation adjustment state (a state where appropriate ball bearing adjustment is maintained).

The above-described rotation operation of the first lock nut 16 is performed by tightening a tightening jig (not shown) in the engaging recesses 16a for locking the tightening jig formed at a plurality of outer peripheral surfaces of the first lock nut 16. No.) is locked.

As described above, since the unit body U3 in which the above-mentioned respective elements 3, 10, 12, 14, 15, 16, 17, 23, 24 are integrated is configured, the factory of subassemblies these respective elements When transporting each of the above-mentioned elements from the assembly station to another assembly station in the factory where they are assembled to the hanger pipe 19 of the bicycle, each of these elements does not come apart from each other, and the transportability is improved. You can

Next, the order of assembling the above-described bicycle crankshaft bearing structure to the bicycle hanger pipe 19 will be described. First, the unit body U3 shown in FIG. 6 (however, the elements 18 and 22 shown by phantom lines in FIG. 6 are removed) is inserted from the right side to the left side of the hanger pipe 19 described above, and is inserted into the right side screw hole 20. The threaded portion 13 of the first fixed nut 12 described above is screwed. When tightening the first fixed nut 12, the above-described tightening operation is performed using the plurality of flat portions 12c formed on the outer peripheral surface of the first fixed nut 12.

Next, the screw portion 18 a of the second fixing nut 18 is inserted into the screw hole 21 on the left side of the hanger pipe 19 so that the second fixing nut 18 is arranged on the outer peripheral side and the outer end side of the outer race 14. Screw together. After that, the second lock nut 22 is tightened and fixed to the threaded portion 18a of the above-mentioned second fixed nut 18, and a series of assembling is completed. The second lock nut 22 may be omitted. Further, a chain sprocket for driving rear wheels is attached to the chain sprocket side A of the crankshaft 3 described above, and cranks are attached to both left and right ends of the crankshaft 3.

In summary, the bearing structure of the bicycle crankshaft can be easily integrated into one unit (see the unit U3 in FIG. 6), and the unit structure itself can be rotationally adjusted (ball contact adjustment). There is an effect that can be done. Therefore, when assembling the unitized structure to the hanger pipe 19 of the bicycle, there is an effect that it is possible to easily assemble the structure, even if it is artificial, without requiring any skilled work. In addition, since the rotation adjustment (ball contact adjustment) is completed in the unitized state described above, the second lock nut 22 shown in FIG. 2 can be omitted.

As shown in the above embodiment, the one side ball bearing 10 arranged on the concave curved outer surface 5 on the chain sprocket side A of the crankshaft 3 is mounted on the concave curved inner surface 11 of the first fixing nut 12. If directly supported, the conventional outer race can be omitted on the chain sprocket side A, and the diameter of the ball bearing 10 can be set to a large diameter. Therefore, it is possible to improve the weight and strength, increase the withstand load on the drive side, and reduce the number of parts and the number of assembling steps.

The sealing members 23 and 24 can prevent dust and the like from entering from the outside of the bicycle, and the connecting pipe 17 can prevent water and the like from entering the hollow frame of the bicycle. Therefore, there is an effect that a good rust prevention effect can be maintained.

Further, the left and right ball bearings 15, 10 are pulled inward while maintaining the rotation adjustment (ball contact adjustment) state by the three members of the outer race 14, the connecting pipe 17, and the first fixing nut 12 described above. Since it is held in such a manner, it is not necessary to form a ring groove for preventing the ball bearing from slipping off at the small-diameter side end portion of each of the concave curved outer surfaces 4 and 5 of the crankshaft 3. Since the ring also becomes defective, there is an effect that the structure can be simplified.

In the correspondence between the configuration of the present invention and the above-described embodiment, the lock nut of the present invention corresponds to the first lock nut of the embodiment, but the present invention is limited to only the configuration of the above-described embodiment. It is not something that will be done.

[Brief description of drawings]

FIG. 1 is a side view showing a bearing structure of a bicycle crankshaft according to the present invention.

FIG. 2 is a sectional view of FIG.

FIG. 3 is a perspective view showing a holding state of the one-side ball bearing.

FIG. 4 is an enlarged cross-sectional view of a first fixing nut.

FIG. 5 is an exploded view showing a state where the bearing structure is being assembled.

FIG. 6 is a side view showing a state where the bearing structure is integrated into a unit.

[Explanation of symbols]

 1, 2 ... Flange portion 3 ... Crank shaft 4, 5 ... Recessed curved outer surface 9 ... Retainer 10 ... One side ball bearing 11 ... Recessed curved inner surface 12 ... First fixing nut 12b ... Screw hole 14 ... Outer race 14a ... Screw portion 15 ... Other side ball bearing 16 ... First lock nut 17 ... Connection pipe 17a ... One side screw part 17b ... Other side screw hole 18 ... Second fixing nut A ... Chain sprocket side B ... Anti-chain sprocket side

Claims (1)

[Scope of utility model registration request] 1. A crankshaft integrally formed with flanges at left and right positions, the crankshaft connecting the flange and the shaft outer periphery with a concave curved outer surface, and a crankshaft arranged on the chain curved sprocket side of the crankshaft. One side ball bearing retained by a retainer, a first fixing nut having a concave curved inner surface for rollingly retaining the one side ball bearing formed on the inner circumference, and a concave curved outer surface of the crankshaft on the side opposite to the chain sprocket. The other side ball bearing that is disposed in the outer race and is held by the outer race, one side screw portion that is screwed into the inner end side screw hole of the first fixing nut, and the other side that is screwed into the inner end side screw portion of the outer race. A connection pipe having a screw hole and disposed between the first fixing nut and the outer race so as to be positionally adjustable, and the connection pipe screwed into the screw portion of the outer race. Bearing structure connecting position and a lock nut for variably adjusting the outer peripheral side and bicycle crank shaft and a second locking nut disposed on the outer end side of the outer race of.