Crank and crankset assembling structure

Abstract

The utility model discloses a crank and chain wheel assembling structure which comprises a crank and a chain wheel, a mounting shaft is arranged on the head portion of the crank, and the mounting shaft protrudes out of the mounting face of the crank. An outer spline is arranged on the outer portion of the installation shaft in the circumferential direction and is close to the installation face of the crank. The chain wheel is provided with a mounting hole used for being connected with the mounting shaft, the mounting shaft penetrates through the mounting hole and is connected with a locking ring, and the locking ring is used for fixedly connecting the chain wheel to the crank. An inner spline matched with the outer spline is arranged in the mounting hole, the outer spline and the inner spline are the same in structure, the longitudinal section of each tooth type of the outer spline is an isosceles trapezoid, and the included angle of the two sides of the isosceles trapezoid is 45 degrees. The crankset is fixedly connected to the crank through the locking ring, and stability and reliability of assembling of the crank and the crankset are guaranteed. The lock ring can be conveniently and efficiently connected and detached, so that the chain wheel is conveniently and efficiently mounted and detached. The tooth-shaped line of the spline is smooth, transition is natural, convenient and effective matching of the spline is achieved, and effectiveness and consistency of spline matching are improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to a bicycle accessory technical field, concretely relates to a crank and cogwheel assembly structure. BACKGROUND

[0002] Bicycle riding has become a more and more widespread means of transportation and form of recreation, and in addition, bicycle riding has become a more and more popular competitive sport for both amateur enthusiasts and professional athletes. Whether the bicycle is used for recreation, transportation, or competition, bicycle manufacturers are continually improving the various components of the bicycle.

[0003] The crank structure is an important component of the bicycle, which connects the cogwheel and the pedal. At present, the installation mode of the cogwheel and the crank includes that the spline matched with the cogwheel is arranged at the root of the crank shaft, and the cogwheel is fastened to the crank through a locking member. The defects of the above installation mode include that the tooth top of the spline on the cogwheel and the crank is usually an acute angle or a right angle, and the splines cannot be conveniently, effectively and stably matched; the installation process of the locking member is complicated, and the cogwheel cannot be stably and effectively fastened to the crank. SUMMARY

[0004] The utility model aims at providing a crank and cogwheel assembly structure, the spline of the crank and the cogwheel can realize convenient, effective, stable and consistent matching, and the cogwheel can be stably and effectively connected to the crank through a locking ring.

[0005] Therefore, the utility model provides a crank and cogwheel assembly structure, including the crank and the cogwheel, the head of the crank is equipped with the installation shaft, the installation shaft protrudes from the installation surface of the crank and is arranged, the outside circumferential surface of the installation shaft is equipped with the outer spline, and the outer spline is arranged close to the installation surface of the crank, the cogwheel is equipped with the installation hole for connecting the installation shaft, the installation shaft passes through the installation hole and is connected with the locking ring, the locking ring is used for fixing and connecting the cogwheel on the crank, the installation hole is equipped with the inner spline matched with the outer spline, the inner edge of the inner spline is evenly arranged around the shaft center of the installation shaft relative to the outer edge of the outer spline, the longitudinal section of each tooth type of the outer spline is isosceles trapezoid, the two side angles of the isosceles trapezoid are 45 DEG, the outer spline and the inner spline are clearance fit, the upper base length of the corresponding trapezoid of the outer spline is 2.2-2.7mm, the upper base length of the corresponding trapezoid of the inner spline is 2.7-2.8mm, the outer diameter of the outer spline is 32.8-37.9mm, and the inner diameter of the outer spline is 34.25-34.75mm, the outer diameter of the inner spline is 38.05-37.95mm, and the inner diameter of the inner spline is 34.8-34.9mm.

[0006] Preferably, the tooth top of the outer spline is provided with a round corner, and the radius of the round corner is 1.1mm.

[0007] Preferably, the number of teeth of the outer spline is not greater than the number of teeth of the inner spline.

[0008] Preferably, the outer spline is provided with an outer tooth missing position, and the inner spline is provided with an inner tooth missing position corresponding to the outer tooth missing position.

[0009] Preferably, the crank is provided with a plurality of weight reduction holes along the length direction of the crank.

[0010] Preferably, the lock ring is threadedly connected to the mounting shaft, and the outer wall of the lock ring is provided with a plurality of key teeth at equal intervals.

[0011] Preferably, the outer diameter of the lock ring is greater than the outer diameter of the inner spline.

[0012] Preferably, the side of the tooth disc away from the mounting surface is provided with an annular groove, the annular groove surrounds the outer spline, and the lock ring is fitted in the annular groove.

[0013] Compared with the prior art, the utility model has the advantages and positive effects that:

[0014] The utility model discloses a lock ring is connected tooth disc on the crank, can guarantee the stability and reliability of the assembly of crank and tooth disc, realize the effective connection of tooth disc, effectively avoid tooth disc to separate the crank. Lock ring can conveniently and efficiently connect and detach, thereby can make tooth disc convenient and efficient installation and detachment.

[0015] The outer spline and the inner spline are convenient to process and form, improve the consistency of the processing and forming of the spline, improve the processing yield and processing efficiency of the spline.

[0016] Other features and advantages of the utility model will become more apparent after reading the specific implementation mode of the utility model in combination with the drawings. DRAWINGS

[0017] Figure 1 It is a structure schematic view of one embodiment of the utility model crank and tooth disc assembly structure;

[0018] Figure 2 It is one of partial structure schematic views of one embodiment of the utility model crank and tooth disc assembly structure;

[0019] Figure 3 It is one of structure schematic views of one embodiment of the utility model tooth disc;

[0020] Figure 4is a schematic diagram of the tooth type structure of the outer spline of the utility model;

[0021] Figure 5 is a partial structure schematic diagram of one embodiment of the crank and the toothed disc assembly structure of the utility model;

[0022] Figure 6 is a partial structure exploded view of one embodiment of the crank and the toothed disc assembly structure of the utility model;

[0023] Figure 7 is a schematic diagram of the tooth type structure of the inner spline of the utility model;

[0024] Figure 8 is a structure schematic diagram of one embodiment of the crank of the utility model;

[0025] Figure 9 is a partial structure schematic diagram of one embodiment of the crank and the toothed disc assembly structure of the utility model;

[0026] Figure 10 is a structure schematic diagram of one embodiment of the toothed disc of the utility model. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical scheme and advantages of the utility model more clear and obvious, the following will combine with the drawings and embodiments, and make further detailed description to the utility model.

[0028] As shown in Figures 1-10 the utility model discloses a crank and toothed disc assembly structure, including crank 10 and toothed disc 20, the head of crank 10 is equipped with installation shaft 11, installation shaft 11 protrudes from the installation surface 101 of crank 10 and is arranged;The outer circumferential surface of installation shaft 11 is equipped with outer spline 12, and outer spline 12 is arranged close to the installation surface 101 of crank 10;Toothed disc 20 is equipped with installation hole 21 for connecting installation shaft 11, installation shaft 11 passes through installation hole 21 and is connected with lock ring 14, and lock ring 14 is used to fixedly connect toothed disc 20 on crank 10.

[0029] In the utility model, the head of the crank 10 and the side of the tooth disc 20 connected with the head of the crank 10 are all the mounting surface 101 of the crank 10, the head of the crank 10 is equipped with the through hole 102 penetrating the mounting surface 101, and the mounting surface 101 is equipped with the mounting shaft 11 arranged around the through hole 102. The mounting shaft 11 is a hollow cylindrical body with two open ends, and the mounting shaft 11 protrudes from the mounting surface 101. The outer wall of the mounting shaft 11 is circumferentially provided with external spline 12, which is arranged close to the mounting surface 101 of the crank 10. The outer wall of the mounting shaft 11 is not completely sleeved by the external spline 12, and the end of the mounting shaft 11 protrudes from the external spline 12; in the embodiment, the mounting shaft 11 is fitted in the mounting hole 21, wherein the end of the mounting shaft 11 protrudes from the mounting hole, and the end of the mounting shaft 11 is sleeved with a locking ring 14, which is used for fixedly connecting the tooth disc 20 to the crank 10, so as to ensure the stability and reliability of the assembly of the crank 10 and the tooth disc 20, realize the effective connection of the tooth disc 20, and effectively prevent the tooth disc 20 from separating from the crank 10.

[0030] Specifically, the end of the mounting shaft 11 is circumferentially provided with external threads on the outer wall, the locking ring 14 is circular, and the inner wall of the locking ring 14 is circumferentially provided with internal threads, so that the locking ring 14 can be threadedly connected to the end of the mounting shaft 11, thereby fixedly connecting the tooth disc 20 to the crank 10. In addition, through the threaded connection, the locking ring 14 can be conveniently and efficiently connected and detached.

[0031] Specifically, the outer wall of the locking ring 14 is provided with a plurality of key teeth at equal intervals, which can facilitate the rotation and installation of the locking ring 14.

[0032] Specifically, the outer diameter N of the locking ring 14 is greater than the outer diameter M of the internal spline 22, so that the effective connection of the tooth disc 20 can be realized, and the tooth disc 20 can be effectively prevented from separating from the crank 10.

[0033] The side of the tooth disc 20 away from the mounting surface 101 is provided with an annular groove 23, and the annular groove 23 is arranged around the external spline 22, and the locking ring 14 is fitted in the annular groove 23. By providing the annular groove 23, the installation of the locking ring 14 can be positioned and guided, and the effective and stable connection of the locking ring 14 can be facilitated.

[0034] The inner diameter of the annular groove 23 is greater than the outer diameter N of the locking ring 14, which can meet the installation and connection of the locking ring 14.

[0035] The side of the tooth disc 20 opposite to the mounting surface 101 is provided with a butt joint groove 24, and the mounting surface 101 is fitted in the butt joint groove 24, and the butt joint groove 24 is provided with a butt joint surface abutting with the mounting surface 101. By providing the butt joint groove 24 and the butt joint surface, the connection of the tooth disc 20 and the crank 10 can be positioned and guided, and the direct, stable and effective connection of the tooth disc 20 and the crank 10 can be realized.

[0036] The mounting hole 21 is provided with an inner spline 22 matched with the outer spline 12, and the inner edges of the inner spline 22 are uniformly arranged around the axis of the mounting shaft 11 relative to the outer edges of the outer spline 12, so that the effective matching of the outer spline 12 and the inner spline 22 can be achieved.

[0037] The longitudinal section of each tooth type of the outer spline 12 is isosceles trapezoidal, and the two side angles α of the isosceles trapezoid are 45°. On the one hand, it can facilitate the molding of the spline, improve the consistency of the spline molding, and improve the processing yield and efficiency of the spline. On the other hand, it can make the tooth line smooth and natural, facilitate the convenient and effective matching of the outer spline 12 and the inner spline 22, and improve the effectiveness and consistency of the matching of the outer spline 12 and the inner spline 22.

[0038] The tooth top of the outer spline 12 is provided with a fillet, which can facilitate the effective matching of the outer spline 12 and the inner spline 22, and improve the effectiveness and consistency of the matching of the outer spline 12 and the inner spline 22.

[0039] The outer spline 12 and the inner spline 22 are gap matched, and the spline assembly of the right crank 10 and the tooth disc 20 is set as gap matching to facilitate assembly. At the same time, the gap matching avoids stress interference and stress concentration during assembly, and ensures the stability and accuracy of the disc claw power meter.

[0040] The upper base length L of the trapezoid corresponding to the outer spline 12 is 2.2-2.7mm, and the upper base length T of the trapezoid corresponding to the inner spline 22 is 2.7-2.8mm. The outer diameter D of the outer spline 12 is 32.8-37.9mm, preferably 37.8-37.9mm, and the inner diameter d of the outer spline 12 is 34.25-34.75mm. The outer diameter M of the inner spline 22 is 38.05-37.95mm, and the inner diameter m of the outer spline 12 is 34.8-34.9mm. Through the limitation of the above size parameters, the molding of the spline can be facilitated, the consistency of the spline molding can be improved, and the processing yield and efficiency of the spline can be improved. On the other hand, the effective matching of the outer spline 12 and the inner spline 22 can be facilitated, and the effectiveness and consistency of the matching of the outer spline 12 and the inner spline 22 can be improved.

[0041] The tooth top of the outer spline 12 is provided with a fillet, and the radius of the fillet is 1.1mm.

[0042] The number of teeth of the outer spline 12 can be equal to the number of teeth of the inner spline 22, and the number of teeth of the outer spline 12 can also be less than the number of teeth of the inner spline 22, which is not limited specifically herein.

[0043] The outer spline 12 is provided with an outer tooth missing position 13, and the inner spline 22 is provided with an inner tooth missing position 25 corresponding to the outer tooth missing position 13. The tooth missing position refers to avoiding one or more teeth on the outer spline 12 and the inner spline 22. In this embodiment, one tooth is avoided on the outer spline 12 and the inner spline 22.

[0044] The design avoids 1 tooth, and the inner spline 22 also avoids 1 tooth corresponding to the outer spline 12; through the 1 tooth avoided on the spline, the foolproof and reverse installation can be prevented, and the outer spline 12 and the inner spline 22 can be accurately and effectively matched.

[0045] The crank 10 is provided with a plurality of lightening holes 15 along the length direction at equal intervals, the weight of the crank 10 can be reduced, the crank 10 can be stable and reliable in structure, high in strength and long in service life. Figure 8 As shown in the figure, the number of the lightening holes 15 is three, and the three lightening holes 15 are symmetrically distributed.

[0046] The utility model discloses a crank 10 outer spline 12 and the inner spline 22 of tooth disc 20 are set to the same tooth shape structure, and all tooth top of spline tooth is set to fillet, and spline can be integrated molding when the crank 10 or tooth disc 20 is processed, and its processing technology is simple and convenient, improves the processing efficiency.

[0047] The above examples are only used to illustrate the technical scheme of the utility model, and not to limit it; although the utility model is explained in detail with reference to the foregoing examples, the technical scheme recorded in the foregoing examples can still be modified, or part of the technical features can be replaced equivalently for the ordinary skilled in the art; and the modification or replacement does not make the essence of the corresponding technical scheme deviate from the spirit and range of the technical scheme claimed by the utility model.

Claims

1. A crank and chainring assembly structure, comprising a crank and a chainring, characterized in that, The crank head is provided with a mounting shaft, which protrudes from the mounting surface of the crank. The mounting shaft has an external spline on its outer circumference, and the external spline is located close to the mounting surface of the crank. The crankset is provided with a mounting hole for connecting the mounting shaft, the mounting shaft passes through the mounting hole and is connected to a locking ring, the locking ring is used to fix the crankset to the crank. The mounting hole is provided with an internal spline that is compatible with the external spline, and the inner edge of the internal spline is evenly arranged around the center of the mounting shaft relative to the outer edge of the external spline. The longitudinal section of each tooth of the external spline is an isosceles trapezoid, and the included angle between the two sides of the isosceles trapezoid is 45°. The external spline and the internal spline are clearance-fitted, the upper base length of the trapezoid corresponding to the external spline is 2.2-2.7mm, and the upper base length of the trapezoid corresponding to the internal spline is 2.7-2.8mm; The outer diameter of the external spline is 32.8-37.9 mm, and the inner diameter of the external spline is 34.25-34.75 mm; The outer diameter of the internal spline is 38.05-37.95 mm, and the inner diameter of the internal spline is 34.8-34.9 mm.

2. The crank and chainring assembly structure as described in claim 1, characterized in that, The tooth tips of the external spline are rounded, and the radius of the rounded corner is 1.1 mm.

3. The crank and chainring assembly structure as described in claim 1, characterized in that, The number of teeth on the external spline is not greater than the number of teeth on the internal spline.

4. The crank and chainring assembly structure as described in claim 1, characterized in that, The external spline has an external missing tooth position, and the internal spline has an internal missing tooth position corresponding to the external missing tooth position.

5. The crank and chainring assembly structure as described in claim 1, characterized in that, The crank is provided with multiple weight-reducing holes symmetrically along its length.

6. The crank and chainring assembly structure as described in claim 1, characterized in that, The locking ring is threaded onto the mounting shaft, and the outer wall of the locking ring is provided with multiple key teeth at equal intervals.

7. The crank and chainring assembly structure as described in claim 1, characterized in that, The outer diameter of the locking ring is larger than the outer diameter of the internal spline.

8. The crank and chainring assembly structure as described in claim 1, characterized in that, The toothed ring has an annular groove on the side opposite to the mounting surface. The annular groove surrounds the external spline, and the locking ring engages within the annular groove.

9. The crank and chainring assembly structure as described in claim 1, characterized in that, The toothed plate has a mating groove on the side opposite to the mounting surface. The mounting surface fits into the mating groove, and the mating groove has a mating surface that fits and mates with the mounting surface.

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