TWM452132U - Assembly structure of crank arm and crank axle of bicycle - Google Patents

Description

Combination structure of bicycle crank arm and crank mandrel

The present invention relates to a combination structure of a bicycle crank arm and a crank mandrel, and more particularly to a structure of a crank arm and a crank mandrel for bicycle installation which can uniformly disperse stress.

At present, the bicycle frame is generally provided with a five-way pipe, which can be passed through a crankshaft and combined with a crank arm having a pedal at the two ends, and then combined with the five-way pipe. The sprocket wheel provides power for pedaling to drive the bicycle forward.

The structure of the crank arm and the crank mandrel of the common bicycle five-way pipe, such as the patent "101. The bicycle crankshaft with radial protrusion" announced by the mainland on December 1, 2010, as shown in the fifth figure. It is shown that a crank arm (B) is fixed to a five-way pipe (A), and a crank mandrel (C) is fixed in the crank arm (B), and the crank mandrel (C) is hollow, thereby The weight can be reduced, and the first end of the crank mandrel (C) is provided with a flange (C1) for extending through the crank arm (B) by the flange (C1) and the crank arm ( The boss (B1) of B) can be axially abutted, and the crank arm (B) and the crank mandrel (C) are fixed to each other by interference fit, and the axial force is transmitted to the boss via the flange (C1) (B1) ), then passed to the second end of the crank mandrel (C) and the other crank arm (B), and finally conveyed the force to the tooth set.

However, in such a configuration, since the axial pressing force is concentrated from the outside to the inside, it is necessary to have a flange (C1) as a starting point feature, and the middle of the tight fitting interference greatly reduces the axial tightness. Force, at the same time there will be stress concentration and easy to cause the crank mandrel (C) to break, its stress distribution Refer to Appendix 1 for the shape [Fig. 1 is a sectional view of the combination of the crank arm and the crank mandrel, Fig. 2 is the force diagram of the crank arm, and Fig. 3 is the stress distribution after the combination of the two crank arms and the crank mandrel. Schematic diagram, Fig. 4 is a cross-sectional view of the stress distribution of the two crank arms combined with the crank mandrel. Figure 5 is a schematic diagram of the stress distribution on the other side after the combination of the two crank arms and the crank mandrel. Figure 6 is a two crank arm. A cross-sectional view of the stress distribution on the other side after combination with the crank mandrel. When there is a gap between the flange (C1) and the boss (B1), the axial pressing force cannot be fully exerted. At the same time, the problem arises from the inability to be axially strong and tight, and the potential for looseness and slippage. Furthermore, the exposure of the flange (C1) is more difficult to prevent the penetration of corrosive foreign bodies such as rainwater, causing potential corrosion and affecting the tightness of interference; it is quite unsatisfactory in use.

Therefore, in view of the combination of the crank arm and the crank mandrel of the bicycle five-way pipe, the above-mentioned shortcomings are used in the present invention. Therefore, the present invention provides a combination structure of a bicycle crank arm and a crank mandrel, which is provided with a first a cranking arm is provided with a first fixing hole, the first fixing hole is provided with a first end and a second end, and an inner wall of the first end is provided with a boss, The boss extension ring is provided with an arc bump, and the arc bump is provided with a first limiting surface, and the inner wall of the second end is recessed with a first stopping portion, and the fixing portion is provided a ring groove is disposed in the ring groove, an O-ring is disposed therein, and the O-ring abuts against the first stopping portion; a crank mandrel is threadedly fixed to the first crank arm The crank mandrel is provided with a third end and a fourth end. The outer edge of the third end is convexly provided with a fixing portion, and the connecting portion of the fixing portion and the crank mandrel is An arc recess is provided, and the arc recess is provided with a first The second limiting surface is in close contact with the first limiting surface.

The first limiting surface and the second limiting surface are respectively formed in a matching inverted R angle shape.

The first crank arm extends with a first step bar.

The crank mandrel is configured to be hollow.

The fourth end is provided with a screw hole, and the screw hole is screwed with a screwing element.

The present invention further includes a second crank arm fixed to the fourth end of the crank mandrel, the second crank arm is provided with a second fixing hole, and the second fixing hole is provided with a relative The fifth end and the sixth end are recessed with a second stop, and the second crank arm is extended with a second step.

This creation has the following advantages:

1. The creation uses the boss to closely fit the fixing portion, so that the contact surface is enlarged to increase the supporting area of the force.

2. The second limiting surface of the creation and the first limiting surface can be closely fitted, thereby converting the generated stress into axial force and radial force respectively, so that the stress can be evenly dispersed without mutual Interference, the need for axially perfect tension and better axial fastening safety.

3. The creation uses the O-ring in the ring groove to abut against the first stop of the first crank arm, thereby preventing corrosive liquid such as rain or sweat from infiltrating into the interior of the five-way pipe, thereby shortening its use. life.

First, referring to the first figure and the second figure, the present embodiment includes a first crank arm (1), a crank mandrel (2) and a second crank arm (3), wherein: the first crank arm (1) is provided with a first fixing hole (11), the first fixing hole (11) is provided with a first end (12) and a second end (13), wherein the first The inner wall of the end (12) is provided with a boss (14), the boss (14) is provided with an arc bump (15), and the arc bump (15) is provided with an inverted R angle shape. a first limiting surface (16), the inner wall of the second end (13) is provided with a first stopping portion (17), and the first crank arm (1) is extended with a first stepping rod (18).

a crank mandrel (2), which is threaded and fixed to the first crank arm (1), the crank mandrel (2) is hollow, and is provided with a third end (21) and a third end The fourth end (22), wherein the outer edge of the third end (21) is convexly provided with a fixing portion (23), the fixing portion (23) is provided with a ring groove (24), and the ring groove (24) is provided therein. An O-ring (25) is inserted into the O-ring (25) and reliably abuts against the first stop (17) of the first crank arm (1), and the fixing portion (23) and the crank spindle (2) The joint is provided with an arc recess (26), and the arc recess (26) is provided with a second limiting surface (27) having an inverted R angle shape, and the second limiting surface (27) is The first limiting surface (16) is in close contact with the first limiting surface (16), and the fourth end (22) is provided with a screw hole (28) (as shown in the fourth figure), the screw hole (28) is screwed together Screw solid element (29).

a second crank arm (3) fixed to the fourth end (22) of the crank mandrel (2), the second crank arm (3) is provided with a second fixing hole (31), the second The fixing hole (31) is provided with a fifth end (32) and a sixth end opposite to each other (33), wherein the fifth end (32) is recessed with a second stopping portion (34), and the second crank arm (3) is extended with a second stepping lever (35).

When assembled, as shown in the second, third and fourth figures, a right-handed sleeve (D), a left-handed sleeve (E) and two bearings (F) are respectively arranged inside the five-way pipe (A). ), the right-handed sleeve (D) and the left-handed sleeve (E) can be screwed to each other, and the two bearings (F) fix the right-handed sleeve (D) and the left-handed sleeve (E) to the five Passing through the inside of the tube (A), then passing the crank mandrel (2) through the first fixing hole (11) of the first crank arm (1), and then passing through the right rotating sleeve (D) and the left rotating sleeve (E) and after the two bearings (F), the third end (21) of the crank mandrel (2) is interference-fitted with the first fixing hole (11), and the inside of the ring groove (24) The O-ring (25) can abut against the first stop portion (17) of the first crank arm (1) to prevent corrosive liquid such as rain or sweat from penetrating into the interior of the five-way pipe (A), and The boss (14) is in close contact with the fixing portion (23) such that the second limiting surface (27) of the arc recess (26) of the crank mandrel (2) is associated with the first crank arm (1) The first limiting surface (16) is tightly abutted, and the combination of the boss (14) and the fixing portion (23) is used to increase the contact surface thereof to increase the supporting area of the force. The second limiting surface (27) is in contact with the first limiting surface (16), so that the stress generated when the rotation is generated can be converted into an axial force and a radial force, respectively. The force and the radial force do not interfere with each other, so that the stress can be evenly dispersed. For the stress distribution, please refer to the attached figure (Figure 1 is a combination of the first crank arm and the crank mandrel, Figure 2 The figure is the force diagram of the first crank arm, and the figure 3 is the stress distribution diagram of the first crank arm, the crank mandrel and the second crank arm. The figure 4 is the first crank arm, the crank mandrel and the second. The cross-sectional view of the stress distribution after the combination of the crank arms, the fifth is the first crank arm, the crank mandrel and the second song The stress distribution diagram of the other side after the combination of the shank arms, FIG. 6 is a cross-sectional view of the stress distribution of the other side after the combination of the first crank arm, the crank mandrel and the second crank arm, thereby achieving the axially perfect pressing force requirement, and Providing better axial fastening safety, and the fourth end (22) of the crank mandrel (2) is sleeved in the second fixing hole (31) of the second crank arm (3), and then The screwing member (29) is screwed to the screw hole (28) and abuts against the second stopping portion (34) of the fifth end (32), so that the screwing member (29) can be completely coupled and fixed to the five-way portion Tube (A).

However, the above is only one of the examples of this creation. When it is not possible to limit the scope of the patent protection of this creation, the simple equivalent changes and replacements made by the scope of the patent application and the contents of the specification are all It shall remain within the scope of the protection covered by the scope of this patent application.

(1)‧‧‧First crank arm

(11)‧‧‧First fixed hole

(12) ‧‧‧ first end

(13)‧‧‧second end

(14)‧‧‧Boss

(15)‧‧‧Arc bumps

(16) ‧‧‧First limit surface

(17)‧‧‧First stop

(18)‧‧‧First step

(2) ‧‧‧ crank mandrel

(21) ‧ ‧ third end

(22) ‧ ‧ fourth end

(23) ‧ ‧ Fixed Department

(24) ‧‧‧ Ring groove

(25)‧‧‧O-ring

(26) ‧ ‧ arc recess

(27) ‧‧‧second limit surface

(28)‧‧‧ screw holes

(29)‧‧‧Spiral components

(3) ‧‧‧second crank arm

(31)‧‧‧Second fixed hole

(32) ‧‧‧ fifth end

(33) ‧‧‧ sixth end

(34) ‧‧‧Second stop

(35) ‧‧‧second step

(A) ‧ ‧ five-way

(B) ‧‧‧ crank arms

(B1)‧‧‧Boss

(C) ‧‧‧ crank mandrel

(C1) ‧‧‧Flange

(D) ‧ ‧ right-handed

(E) ‧ ‧ left-handed

(F) ‧ ‧ bearings

The first picture is a three-dimensional exploded view of the creation.

The second picture is a three-dimensional exploded view of the creation of the five-way tube assembly.

The third figure is a sectional view of the combination of the creation and the five-way pipe assembly.

The fourth picture is a partial enlarged view of the creation.

The fifth figure is a partial sectional view of a conventional five-way pipe.

Figure 1 is a cross-sectional view of a combination of a conventional crank arm and a crank mandrel.

Figure 2 is a schematic diagram of the force of a conventional crank arm.

Attachment 1 to Figure 3 is the combination of the two crank arms and the crank mandrel. Schematic diagram of the stress distribution.

Figure 1 is a cross-sectional view of the stress distribution after the combination of the two crank arms and the crank mandrel.

Figure 5 is a schematic diagram of the stress distribution on the other side of the combination of the two crank arms and the crank mandrel.

Figure 1 is a cross-sectional view of the stress distribution on the other side of the combination of the two crank arms and the crank mandrel.

Figure 2 of the attached figure is a sectional view of the combination of the first crank arm and the crank mandrel.

Figure 2 of Figure 2 is a schematic diagram of the force of the first crank arm of the creation.

Figure 2 is the schematic diagram of the stress distribution after the combination of the first crank arm, the crank mandrel and the second crank arm.

Figure 4 of Figure 2 is a cross-sectional view of the stress distribution after the combination of the first crank arm, the crank mandrel and the second crank arm.

Figure 5 of Figure 2 is a schematic diagram of the stress distribution of the other side of the combination of the first crank arm, the crank mandrel and the second crank arm.

Figure 6 is a cross-sectional view of the stress distribution of the other side of the combination of the first crank arm, the crank mandrel and the second crank arm.

(1)‧‧‧First crank arm

(11)‧‧‧First fixed hole

(12) ‧‧‧ first end

(13)‧‧‧second end

(14)‧‧‧Boss

(15)‧‧‧Arc bumps

(16) ‧‧‧First limit surface

(17)‧‧‧First stop

(2) ‧‧‧ crank mandrel

(21) ‧ ‧ third end

(23) ‧ ‧ Fixed Department

(24) ‧‧‧ Ring groove

(25)‧‧‧O-ring

(26) ‧ ‧ arc recess

(27) ‧‧‧second limit surface

(F) ‧ ‧ bearings

Claims (6)

A combination of a bicycle crank arm and a crank mandrel includes: a first crank arm having a first fixing hole, the first fixing hole being provided with a first end and a second The end wall of the first end is provided with a boss, the boss extension ring is provided with an arc bump, and the arc bump is provided with a first limiting surface, and the second end is The inner wall is recessed with a first stopping portion, the fixing portion is provided with a ring groove, and the ring groove is provided with an O-ring, and the O-ring abuts against the first stopping portion a crank mandrel, the threaded mandrel is fixed to the first crank arm, the crank mandrel is provided with a third end and a fourth end, and the outer edge of the third end is convex a fixing portion, an arc concave portion is disposed at a joint of the fixing portion and the crank mandrel, wherein the arc concave portion is provided with a second limiting surface, and the second limiting surface is opposite to the first limit The plane is close to the fit. The combined structure of the bicycle crank arm and the crank mandrel according to claim 1, wherein the first limiting surface and the second limiting surface are respectively formed in a matching inverted R angle shape. The combination of the bicycle crank arm and the crank mandrel according to claim 1, wherein the first crank arm extends with a first step. The combination structure of the bicycle crank arm and the crank mandrel according to claim 1, wherein the crank mandrel is hollow. The combination of the bicycle crank arm and the crank mandrel according to claim 1, wherein the fourth end is provided with a screw hole, and the screw hole is screwed with a screwing element. The combination structure of the bicycle crank arm and the crank mandrel according to claim 1 is further provided with a second crank arm fixed to the fourth end of the crank mandrel, and the second crank arm is provided with a Second fixing hole, said The second fixing hole is provided with a fifth end and a sixth end. The fifth end is recessed with a second stopping portion, and the second crank arm is extended with a second step.