CN214875372U

CN214875372U - Connecting structure of chain wheel and crank middle shaft

Info

Publication number: CN214875372U
Application number: CN202121869448.9U
Authority: CN
Inventors: 冯锦添; 邓龙洵; 王春青; 卞青峰
Original assignee: Shandong Rardus Composite Materials Co ltd
Current assignee: Shandong Rardus Composite Materials Co ltd
Priority date: 2021-08-11
Filing date: 2021-08-11
Publication date: 2021-11-26
Anticipated expiration: 2031-08-11

Abstract

The utility model relates to a bicycle accessory technical field, concretely relates to sprocket and centraxonial connection structure of crank, including sprocket, sprocket support and crank axis, the sprocket is installed on the sprocket support, through splined connection between sprocket support and the crank axis, and the spline is just being the tapering spline including setting up epaxial external splines in the crank and setting up the internal spline on the sprocket support with external splines intermeshing. The utility model discloses a tapering spline is with crank axis and sprocket support cooperation, has increased sprocket support and the epaxial torsion of internal and external splines in, and the screw atress reduces to effectively reduce the screw quantity of fixed crank axis and sprocket support, only can accomplish the fixed of axis and sprocket with 4 screws. The number of screws is reduced, and the weight of the bicycle is reduced, so that the development of walking light weight is facilitated.

Description

Connecting structure of chain wheel and crank middle shaft

Technical Field

The utility model relates to a bicycle accessory technical field, concretely relates to sprocket and centraxonial connection structure of crank.

Background

Bicycles are a traditional industry, have a history of over 100 years, and due to the problems of environmental protection and traffic, bicycles become a favorite means of transportation and fitness for residents of all countries in the world, especially developed countries, and the center of gravity of the bicycle industry in the world is being changed from a traditional transportation means instead of walking to sports, mountain land and leisure. The bicycle driving system consists of pedal, middle shaft, chain wheel, crank, chain, flywheel, back shaft, back wheel and other parts. The pedal force of the foot is transmitted by the crank, chain wheel, chain, flywheel, rear axle and other parts, so that the bicycle is made to move forward continuously.

The pedal component is assembled on the left crank and the right crank of the middle shaft component, and is a device for converting translational force into rotational force. Therefore, whether the structure and specification of the pedal component are proper or not directly influences whether the foot placing position of the rider is proper or not and whether the driving of the bicycle can be smoothly carried out or not. The center of the set of driving system is the chain connection of the chain wheel and the crank middle shaft, a set of middle shaft system with rigorous technology and excellent performance becomes one of the weight standards for bicycle evaluation.

The common crank and the middle shaft on the market have various connection forms, including a square hole middle shaft, an integrated middle shaft, a spline middle shaft and the like. In the connection mode, the chain wheel is fixed on the crank, the spline middle shaft has more and finer contact surfaces, can be better combined with the crank, is not easy to loosen, has larger diameter of the shaft center and high strength and good force transmission, is accepted by broad users, and is more commendable by experts in the industry. The mode of connection of ordinary sprocket and crank axis has its self defect, and the resistance that produces among the simple spline combination can not satisfy the in-process of riding, produces the safety problem easily, in order to solve this problem, uses the screw reinforcement usually. Common manufacturers use 8-12 screws. Although the reinforcing mode solves most potential safety hazards in the riding process, the weight and the installation steps of the bicycle are increased.

SUMMERY OF THE UTILITY MODEL

The utility model provides a not enough to prior art, the utility model provides a sprocket and centraxonial connection structure of crank has increased sprocket support and the epaxial torsion of internal and external splines in crank, reduces screw quantity simultaneously, for bicycle itself subtracts the weight, helps walking lightweight development.

The utility model discloses a realize through following technical scheme:

the utility model provides a sprocket and centraxonial connection structure of crank, includes sprocket, sprocket support and crank axis, and the sprocket is installed on the sprocket support, through splined connection between sprocket support and the crank axis, the spline is including setting up epaxial outer spline in the crank and setting up the internal spline on the sprocket support, and internal spline and external spline intermeshing just are the tapering spline.

Parallel between epaxial external splines in traditional structure and the epaxial internal splines in sprocket, easily break away from, this scheme is compared in traditional design, through the torsion that tapering spline design has multiplicable sprocket support and epaxial internal and external splines in, promotes the stability of connecting.

Furthermore, the axial extension lines of the teeth and the grooves of the inner spline and the outer spline form included angles of 2-10 degrees with the central axis of the crank central shaft.

The axial extension lines of the teeth and the grooves of the inner spline and the outer spline form an included angle of 2-10 degrees with the central line of the crank middle shaft, the inner spline and the outer spline are combined more tightly, and the crank middle shaft and the chain wheel bracket are fixed more firmly.

Furthermore, the external spline is arranged on a spline disc of the crank middle shaft, and the internal spline is arranged on the peripheral wall of the center of the chain wheel bracket provided with the spline groove.

Furthermore, a first threaded hole is formed in the spline disc, a second threaded hole is formed in the spline groove bottom wall of the chain wheel support corresponding to the first threaded hole, and the first threaded hole and the second threaded hole are provided with tensioning screws.

Furthermore, four tensioning screws are arranged. The taper spline matching can increase the torsion, reduce the number of the screws, realize stable connection only through four screws, reduce the overall balance weight and contribute to the lightweight development.

Further, the central angle of two adjacent tensioning screws is 90 degrees.

Four screws are distributed in the spline disc and the spline grooves in a square shape, so that a stable symmetrical structure can be formed, the stress is uniform, and the connection stability is ensured.

Further, the number of the inner splines and the number of the outer splines are 20.

The utility model has the advantages that:

the utility model discloses a tapering spline is with crank axis and sprocket support cooperation, has increased sprocket support and the epaxial torsion of internal and external splines in, and the screw atress reduces to effectively reduce the screw quantity of fixed crank axis and sprocket support, only can accomplish the fixed of axis and sprocket with 4 screws. The number of screws is reduced, and the weight of the bicycle is reduced, so that the development of walking light weight is facilitated.

Drawings

Fig. 1 is a schematic view of the overall structure of the present invention;

FIG. 2 is a side view of FIG. 1;

FIG. 3 is a schematic structural view of the middle sprocket bracket mounting sprocket of the present invention;

fig. 4 is a schematic structural view of the middle crank middle shaft of the present invention;

fig. 5 is a side view of fig. 4.

Shown in the figure:

1. sprocket, 2, sprocket support, 3, spline groove, 4, second screw hole, 5, internal spline, 6, crank axis, 7, spline dish, 8, external spline, 9, first screw hole, 10, straining screw.

Detailed Description

In order to clearly illustrate the technical features of the present solution, the present solution is explained below by way of specific embodiments.

The utility model provides a sprocket and centraxonial connection structure of crank, includes sprocket 1, sprocket support 2 and crank axis 6, sprocket 1 installs on sprocket support 2, through splined connection between sprocket support 2 and the crank axis 6, the spline is including setting up external splines 8 on crank axis 6 and setting up internal splines 5 on sprocket support 2, external splines 8 set up on the spline dish 7 of crank axis 6, internal splines 5 set up in sprocket support 2 center offer on the perisporium of spline groove 3. First screw hole 9 has been seted up on the spline dish 7, and second screw hole 4 has been seted up to 3 diapire of spline groove of sprocket support 2 corresponding first screw hole 9, and straining screw 10 is installed to first screw hole 9 and second screw hole 4. Four tensioning screws 10 are all flat head screws, and the central angle of two adjacent tensioning screws 10 is 90 degrees.

The internal spline 5 and the external spline 8 are mutually meshed and are both tapered splines. The number of the taper splines is not fixed, the shape of the splines is not fixed, and as an implementation mode of the embodiment, the number of the inner splines 5 and the number of the outer splines 8 are both 20.

The axial extension lines of the teeth and the grooves of the inner spline and the outer spline form included angles of 2-10 degrees with the central axis of the crank central shaft 6. In this embodiment, the spline tapers at a 3 included angle.

The embodiment is applied to the connection of the bicycle crank middle shaft 6 and the chain wheel 1, and belongs to a special connection mode. The traditional connection mode of the spline and the chain wheel support 2 is simple spline connection, 8-12 screws are needed for fixing, the outer spline 8 on the middle shaft 6 and the inner spline 5 on the chain wheel are parallel and are easy to break away from each other, in order to fix, most of the traditional connection mode adopts screws for fixing, the number of the screws is increased for the bicycle, and the design becomes the defect of the bicycle in the bicycle industry of light weight. The utility model discloses in, the tooth of internal and external spline 8, groove axial extension all form 3 contained angles with the axis central line, and the internal and external spline combines more tightly, and axis 6 is more firm with sprocket support 2's fixed. Through the design point, the torsion of the internal spline and the external spline on the chain wheel support 2 and the middle shaft 6 is increased, the stress of the screws 10 is reduced, so that the number of the screws for fixing the middle shaft 6 and the chain wheel support 2 is effectively reduced, and the middle shaft 6 and the chain wheel 1 can be fixed only by 4 screws 10.

Of course, the above description is not limited to the above examples, and technical features of the present invention that are not described in the present application may be implemented by or using the prior art, and are not described herein again; the above embodiments and drawings are only used for illustrating the technical solutions of the present invention and are not intended to limit the present invention, and the present invention has been described in detail with reference to the preferred embodiments, and those skilled in the art should understand that changes, modifications, additions or substitutions made by those skilled in the art within the spirit of the present invention should also belong to the protection scope of the claims of the present invention.

Claims

1. The utility model provides a sprocket and centraxonial connection structure of crank, includes sprocket, sprocket support and crank axis, and the sprocket is installed on the sprocket support, through splined connection between sprocket support and the crank axis, the spline is including setting up epaxial external splines in the crank and setting up the internal spline on the sprocket support, its characterized in that: the internal spline and the external spline are mutually engaged and are both tapered splines.

2. The connecting structure of the chain wheel and the crank middle shaft as claimed in claim 1, wherein: the axial extension lines of the teeth and the grooves of the inner spline and the outer spline form included angles of 2-10 degrees with the central axis of the crank central shaft.

3. The connecting structure of the chain wheel and the crank middle shaft as claimed in claim 1, wherein: the outer spline is arranged on a spline disc of the crank middle shaft, and the inner spline is arranged on the peripheral wall of the center of the chain wheel bracket provided with a spline groove.

4. The connecting structure of the chain wheel and the crank middle shaft as claimed in claim 3, wherein: a first threaded hole is formed in the spline disc, a second threaded hole is formed in the bottom wall of the spline groove of the chain wheel support corresponding to the first threaded hole, and the first threaded hole and the second threaded hole are provided with tensioning screws.

5. The connecting structure of the chain wheel and the crank middle shaft as claimed in claim 4, wherein: four tensioning screws are arranged.

6. The connecting structure of the chain wheel and the crank middle shaft as claimed in claim 5, wherein: the central angle of two adjacent tensioning screws is 90 degrees.

7. The connecting structure of the chain wheel and the crank middle shaft as claimed in claim 1, wherein: the number of the inner splines and the number of the outer splines are both 20.