JPS5922338Y2 - bicycle freewheel - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a bicycle freewheel.

Conventionally, as shown in FIG. 3, this type of bicycle freewheel has a free gear body d, which has a sprocket tooth row a on the outer periphery and a ratchet tooth row on the inner periphery, and ball receivers on both ends of the free gear body d. The surfaces C1 and C2 are concave, and the inner end of the core g, which has a ratchet pawl e embedded in its outer periphery, is bulged out in the shape of a brim to form a ball receiving surface f1, and the ball receiving surface C1 and the ball are The core g with a plurality of steel balls interposed between it and the receiving surface f1.
while inserting it into the free gear body d from the left side in Fig. 3,
A plurality of steel balls k are interposed between the ball receiving surface f2 provided with the screw cap j and the ball receiving surface C2 provided on the free gear body d, and are inserted into the core g from the right side of FIG. It was designed to be screwed on.

However, the conventional freewheel constructed as described above has the following problems.

That is, due to the structure, it is necessary to provide two steel ball support rotation parts (bearing parts) on the left and right (see Figure 3), and these steel ball support rotation parts A and B (bearing parts) are manufactured separately. It must be constructed by assembling the free gear body d, core g, a plurality of steel balls k, and screw cap j.

Therefore, assembly and adjustment required a great deal of effort and skill, resulting in significant inefficiency.

That is, after assembling the free gear body d, the core g, and the screw cover j as shown in Fig. 3, it is necessary to insert the steel balls k to form the bearing part between the surfaces of each ball bearing. This is possible, and when the steel ball is inserted into the free gear body d with the core g, and when the steel ball is screwed with the screw cap j onto the core g, each ball receiver is interposed between the surfaces. Such assembly requires an extremely high level of skill in order to carry out the work quickly and reliably.

In addition, in the above-mentioned conventional freewheel, unevenness in rotational performance of the free gear body d due to dimensional errors in component manufacturing is avoided by using a thin tone plate between the screw cover j and the ratchet pawl embedded portion of the core g. This is corrected by screwing the screw cover J to the optimum position with the help of screw m, and since the dimensional error mentioned above is different for each freewheel, it is difficult to uniformly correct it, so such adjustment is necessary. It required considerable skill to carry out the work quickly and reliably.

All of the above-mentioned problems are due to the basic structure of the bearing part in the conventional freewheel, that is, the ball holder formed on the inner periphery of the free gear body is interposed between the surface and the ball holder of the screw lid. This is due to the structure in which the screw lid is screwed onto the core while adjusting the number of adjustment plates between the ratchet pawl embedded part of the core and the screw lid in order to maintain a constant rotation of the steel ball. , and as long as such a configuration is adopted,
The difficulty of assembly and adjustment was not fundamentally resolved, and automatic assembly and adjustment were not possible.

This invention was devised in order to solve the above problems all at once, and allows mass automatic assembly of the bearing part as one body with the free gear body, eliminating the need for any rotational performance adjustment during assembly as in the past. Aims to provide freewheeling.

Hereinafter, the present invention will be specifically explained based on embodiments shown in the drawings.

Reference numeral 1 designates an annular free gear body which is a driving member, and has a sprocket tooth row 3 protruding from its outer periphery 2 and a steel ball raceway groove 4 formed near one side of its inner periphery to form an outer ring portion of a radial ball bearing portion C. 5 is integrally formed.

6 is a plurality of steel balls 7 on the inside of the outer ring portion 50 in the radial direction;
An inner ring rotatably fitted through 7...,
A steel ball raceway groove 8 is formed on the outer periphery, and a thread 10 is carved on the inner periphery for screwing a core 9, which will be described later.

The radial ball bearing C, which is connected to the outer ring 5, the steel balls 7, 7, . . . and the inner ring 6, is automatically assembled in the same manner as in normal bearing manufacturing.

Reference numeral 11 is a cage that holds the steel balls 7, 7, . . . at predetermined intervals.

Thus, the free gear body 1 integrally constructed with the radial ball bearing portion C is formed.

Further, the ball bearing portion C near one side of the inner circumference of the free gear body 1
A ratchet tooth row 13 that engages with a ratchet pawl 12 provided on the core 9, which will be described later, to restrict the rotational direction of the free gear body 1 in one direction is carved in a portion adjacent to the free gear body 1.

Reference numeral 9 denotes a core which is a driven member to be fitted into the free gear body 1, and one end of its outer circumference is provided with a thread 14 which is threadedly engaged with the thread 10 provided on the inner ring 6. On the other side, a plurality of ratchet pawls 12 are protruded in a portion facing the ratchet tooth row 13 in a freely undulating manner, and a part of the outer circumferential wall at the end portion is made to protrude like a brim to form a dust removal wall 15. It's intimidating.

In the figure, reference numeral 16 indicates a screw thread for fixing the core 9 to the bub (the illustrated path), and 17 indicates a ring spring for biasing the tip of the ratchet pawl 12 in the direction of the ratchet tooth row 13.

In order to assemble the core 9, which is a driven member, configured in this manner, to the free gear body 1, which is a driving member, it is necessary to attach the thread 14 provided on the outer periphery of the core 9, and the inner ring that has been integrally assembled to the free gear body 1 in advance. It is only necessary to screw together and tighten the threads 10 of No. 6, and there is no need to finely adjust the rotational performance of the ball bearing portion C during this assembly.

The freewheel according to the present invention has the following remarkable effects.

First, since the ball bearing integrally formed in the free gear body is a radial ball bearing, only one steel ball supporting rotating part (bearing part) is required, which simplifies the manufacturing process.

That is, in the conventional freewheel, as is clear from FIG. 3, each ball receiving surface C1, f1 . Since C2 and f2 have the shapes shown in the figure, the load from the free gear body a, which is the driving member, will be supported in the diagonal direction via the steel balls, so in order to support the radial load, it is necessary to Two bearing parts (A and B) are required, but according to the present invention, only one bearing part is required.

Second, since the free gear body 1 and the radial ball bearing part C are integrally formed, there is no difficulty in assembly as with conventional freewheels, and difficult fine adjustments to equalize rotational performance are completely omitted. be able to.

In other words, precision machining technology for mass production of ball bearings has already been established in Japan, and bearings with a certain quality (uniform rotational performance and long life) can be automatically assembled and produced in large quantities. Then, the radial ball bearing free gear body according to the present invention can be automatically assembled.

Therefore, since the rotational performance is already constant when the free gear body is manufactured, the footwheel can be assembled by simply screwing a separately produced core into the inner ring integrated with the free gear body.

Thirdly, the diameter of the freewheel can be reduced.

That is, since the portion corresponding to the outer ring of the radial ball bearing portion is integrally formed with the free gear body, it is possible to reduce the diameter of the foot gear body.

If this is applied to a minicycle with small wheels, the gear ratio between the crank gear and the free gear can be increased, so that the minicycle can run faster than the conventional example.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway side view showing an embodiment of the present invention, FIG. 2 is a partially cutaway front view, and FIG. 3 is a partially cutaway side view showing a conventional example. 1...Sprocket teeth, 5...Outer ring, 6...Inner ring, 7...Steel ball, 9...
... Core, 11 ... Cage, 12 ...
・Ratchet pawl, 13... Ratchet tooth row, ・
...Radial ball bearing.

Claims (1)

[Scope of utility model registration request] One end of the free gear body, which has a sprocket tooth row on the outer circumference and a ratchet tooth row on the inner circumference, is slightly extended to form an integral outer ring of the ball bearing. The free gear body and the ball bearing are integrally formed by assembling the inner ring through a ball and a retainer that holds the same, and a core having a ratchet pawl that engages with the ratchet tooth row is assembled to the inner ring. A freewheel for bicycles that is characterized by: