CN209852511U - Bicycle crank structure and chain wheel assembly applying same - Google Patents

Abstract

The utility model discloses a bicycle crank structure and chain wheel subassembly of using this bicycle crank structure, this bicycle crank structure include the crank main part, the one end of crank main part is provided with the mounting hole, the other end is provided with the pedal, the mounting hole is used for connecting the bicycle axis, the crank main part is provided with a plurality of cavities along the axial indent of mounting hole between mounting hole and pedal, the crank main part is formed with two at least strengthening ribs that extend along the length direction of crank main part through a plurality of cavities. The utility model provides a crank structure and applied this crank structure's chain wheel subassembly both can guarantee articulate mechanical properties, can effectively lighten weight again and realize the lightweight, and the practicality is strong.

Description

Bicycle crank structure and chain wheel assembly applying same

Technical Field

The utility model belongs to the technical field of the bicycle, concretely relates to bicycle crank structure and applied this bicycle crank structure's chain wheel subassembly.

Background

The chain wheel assembly of the bicycle comprises a chain wheel, a middle shaft, a left crank and a right crank, wherein the left crank and the right crank are respectively installed at two ends of the middle shaft, and the chain wheel is installed on the middle shaft or on the left crank (or the right crank). The chain is wound on the chain wheel, and the pedals at the tail ends of the left crank and the right crank are pedaled to drive the middle shaft and the chain wheel to rotate, so that the chain is driven, and the rear wheel is driven by the chain. With the pursuit of bicycle enthusiasts for light weight being higher and higher, manufacturers on the market also reduce the weight of the crankset component in various ways, for example, the weight is reduced by changing materials, and aluminum alloy and the like are adopted to replace the traditional steel; or a taper hole extending along the length direction is processed in the center of the end face of the steel for manufacturing the crank, and the taper hole at the middle section of the steel is not completely closed in the subsequent processing, so that a hollow crank is finally formed, and the weight is reduced; or machining a weight reduction groove on the crank to reduce the weight. Although the weight of the crank can be reduced in the first mode, the weight reduction effect cannot meet the requirements of users due to the fact that the crank is of a solid structure; although the crank is produced into a hollow structure in the second mode, the traditional mode is only suitable for steel, the production process is complex, and the production efficiency is low; the third mode is suitable for both steel and materials such as aluminum alloy, however, the arrangement of the weight reduction groove affects the appearance, dust, mud and the like are easily accumulated, the cleaning difficulty is high, the daily maintenance of a user is inconvenient, and meanwhile, the mechanical property of the crank is easily affected by the arrangement of the traditional weight reduction groove. Therefore, no crank structure capable of achieving light weight better is available on the market.

SUMMERY OF THE UTILITY MODEL

In order to solve the problem, the utility model provides a both can guarantee articulate mechanical properties, can effectively lighten weight again and realize lightweight crank structure and use this crank structure's chain wheel subassembly.

The utility model provides a technical scheme that its technical problem adopted is: the utility model provides a bicycle crank structure, includes the crank main part, the one end of crank main part is provided with the mounting hole, the other end is provided with the pedal, the mounting hole is used for connecting bicycle axis, the crank main part is provided with a plurality of cavities along the axial indent of mounting hole between mounting hole and pedal, the crank main part is formed with two at least strengthening ribs that extend along the length direction of crank main part through a plurality of cavities.

As a further improvement of this solution, it further comprises at least one sealing plate mounted on the crank body for closing the cavity.

As a further improvement of the scheme, the concave cavity is provided with one and extends along the length direction of the crank main body, so that two reinforcing ribs are formed on two sides of the crank main body, and the sealing plate closes the concave cavity to form a hollow box-shaped structure.

As a further improvement of the scheme, the reinforcing ribs are provided with dovetail grooves, and clamping pins are arranged on the peripheral sides of the sealing plates and are riveted in the dovetail grooves through the clamping pins.

Further, the utility model provides an use chain wheel subassembly that has above-mentioned bicycle crank structure, including left crank, right crank, axis and chain wheel, left side crank and right crank are installed respectively in centraxonial both ends, the chain wheel is installed on axis or left crank, left side crank and right articulate one end all are provided with and are used for connecting centraxonial mounting hole, the other end all is provided with the pedal, and left crank and right crank are provided with a plurality of cavities along the axial indent of mounting hole between mounting hole and pedal, left side crank and right crank are formed with at least two strengthening ribs that extend along self length direction through the cavity respectively.

As a further improvement of the scheme, sealing plates for closing the concave cavity are arranged on the left crank and the right crank.

As a further improvement of the scheme, the left crank and the right crank are respectively provided with a concave cavity, the concave cavities extend along the length direction of the concave cavities, so that two reinforcing ribs are formed on two sides of the left crank and the right crank, and the sealing plates close the cavities to form a hollow box-shaped structure.

As a further improvement of the scheme, the chain wheel comprises a spoke and a gear ring detachably mounted on the spoke, a plurality of driving teeth are arranged on the outer side of the gear ring around the axis, and a mounting structure connected with a crank or a middle shaft is arranged at the center of the spoke.

As a further improvement of the scheme, a plurality of spoke convex parts are arranged on the outer side of the spoke around the axis, a plurality of buckling concave positions are arranged on the inner side of the gear ring corresponding to the spoke convex parts, and the spoke convex parts can be pressed into the buckling concave positions along the axial direction.

As a further improvement of the scheme, the spoke is made of light materials such as aluminum alloy, carbon fiber or magnesium alloy, and the gear ring is made of materials with good wear resistance such as steel.

As a further improvement of the scheme, a plurality of convex part forming concave positions are formed on the circumferential side of the spoke in an inwards concave mode along the axial direction, a spoke convex part is formed between every two adjacent convex part forming concave positions, and a gear ring convex part matched with the convex part forming concave positions is formed between every two adjacent buckling concave positions.

As a further improvement of the scheme, the spoke comprises an inner spoke ring and an outer spoke ring which are coaxially distributed, and a plurality of spokes which are arranged between the inner spoke ring and the outer spoke ring and used for connecting the inner spoke ring and the outer spoke ring, wherein a convex part forming concave position is arranged on one side surface of the outer spoke ring, and a first weight reduction groove is arranged on the other side surface of the outer spoke ring.

As a further improvement of the scheme, the first lightening groove comprises an annular lightening groove positioned on the inner side of the convex part forming concave position and a tooth-shaped lightening groove arranged in a staggered mode with the convex part forming concave position.

As a further improvement of the scheme, one side surface of the spoke is provided with a second weight reducing groove, and the spoke passes through the second weight reducing groove and is formed with spokes extending along the length direction of the spoke on two sides of the spoke.

As a further improvement of the scheme, one side or two sides of the spoke convex part are provided with convex structures which are convex relative to the root parts of the spoke convex part, and one side or two sides of the buckling concave position are provided with concave structures which are matched with the convex structures.

As a further improvement of the scheme, the spoke and the gear ring are fixed through riveting or interference fit or screw connection.

The utility model has the advantages that: the utility model provides a bicycle crank structure reduces the material through setting up the cavity to weight reduction, and torsion when the crank main part that the bottom of accessible cavity corresponds transmits the pedal atress in the course of the work, through the strengthening rib dispersion the axial when the effort that the pedal receives is for the radial deflection of mounting hole drag the power, consequently the utility model provides a crank structure and the chain wheel subassembly of using this crank structure both can guarantee articulate mechanical properties, can effectively lighten weight again and realize the lightweight, the practicality is strong.

Drawings

The invention will be further described with reference to the following figures and examples:

FIG. 1 is a schematic structural view of a crank body according to the present invention;

FIG. 2 is a schematic structural view of a sealing plate of the present invention;

FIG. 3 is a schematic structural view of a tooth plate of the present invention;

fig. 4 is a schematic structural view of the ring gear of the present invention;

fig. 5 is a schematic front view of the spoke according to the present invention;

fig. 6 is a schematic view of the back structure of the spoke according to the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention, as generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the present invention, presented in the accompanying drawings, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention.

First embodiment

Referring to fig. 1-2, the utility model discloses a bicycle crank structure, including crank main part 3, the one end of crank main part 3 is provided with mounting hole 301, the other end is provided with the pedal, mounting hole 301 is used for connecting the bicycle axis, crank main part 3 is provided with a plurality of cavities 304 along the axial indent of mounting hole 301 between mounting hole 301 and pedal, crank main part 3 is formed with at least two strengthening ribs 302 that extend along the length direction of crank main part 3 through a plurality of cavities 304.

Because the application of force drives the crank pivoted through trampling the pedal in the course of the work, consequently the crank mainly receives along the radial torsion of mounting hole 301, simultaneously because the habit of every user trampling the pedal is different, consequently the application of force direction is not all vertical downwards or along the mounting hole 301 radially, and its application of force direction probably takes place certain deflection relatively the radial of mounting hole 301 to can form one along the axial effort of mounting hole 301, make the crank receive along the axial pulling force of mounting hole 301.

Firstly, the crank body 3 in the embodiment reduces the material by providing the concave cavity 304, and reduces the weight of the crank body 3; secondly, the concave cavity 304 does not penetrate through the crank main body 3, and the torsion force when the pedals are stressed can be transmitted through the crank main body 3 corresponding to the bottom of the concave cavity 304 in the working process, and the axial pulling force when the acting force stressed by the pedals is dispersed by the reinforcing ribs 302 relative to the radial deflection of the mounting holes 301 can be dispersed, so that the mechanical property of the crank main body 3 can be ensured; moreover, this structure both had been applicable to steel, had also been applicable to materials such as aluminum alloy, carbon fiber, magnesium alloy, and the processing degree of difficulty is low, and consequently the crank structure in this embodiment both can guarantee articulate mechanical properties, can effectively lighten weight again and realize the lightweight, and production efficiency is higher than traditional structure, production mode, and the practicality is strong.

As a further improvement of this solution, the crank structure further comprises at least one sealing plate 4, said sealing plate 4 being mounted on the crank body 3 for closing the cavity 304. Therefore, when a user rides on a mountain or muddy road, the phenomenon that dust and mud are accumulated in the concave cavity 304 can be effectively avoided, and the cleaning and the maintenance are convenient.

As shown in the drawings, as a first preferred solution in this embodiment, the cavity 304 is provided with only one and extends along the length direction of the crank body 3, so that two reinforcing ribs 302 are formed on both sides of the crank body 3, and the sealing plate 4 closes the cavity 304 to form a hollow box-shaped structure. Therefore, only one concave cavity 304 is formed in the crank body 3, so that the crank is simple in structure and small in processing difficulty, and production efficiency is improved.

As a second preferred solution in the present embodiment, N cavities 304 are provided on the cavity 304, where N is 2, 3, 4, and 5, and the N cavities 304 are arranged in a row along the length direction of the crank body 3, so that two ribs 302 are formed on both sides of the crank body 3, and N-1 ribs are formed between the two ribs 302, and the two ribs 302 in this structure can improve mechanical properties such as strength and toughness by the rib function.

The sealing plate 4 may be fixedly attached to the crank body 3 by riveting, bonding, screwing, or the like, and as shown in the drawing, the present embodiment is preferably attached by riveting. Specifically, the rib 302 is provided with a dovetail groove, preferably a T-shaped dovetail groove 303, and the sealing plate 4 is provided with a retaining pin 401 on the circumferential side and is riveted in the T-shaped dovetail groove 303 by the retaining pin 401. Alternatively, after the clip 401 is fitted into the T-shaped dovetail groove 303, the rib 302 is riveted to fix the crank body 3 to the seal plate 4.

The seal plate 4 is configured to fit the inner wall of the rib 302, so that the seal plate 4 does not protrude from the surface of the crank body 3 when the seal plate is mounted on the crank body 3, and the thickness of the crank body 3 is not increased.

In the second preferred embodiment, the rib has a height lower than that of the rib 302 so as not to hinder the sealing plate 4 from being pressed between the ribs 302.

The mounting hole 301 in this embodiment can be flexibly selected according to the need, for example, it is configured as an internal spline or a square hole, and is not limited in detail here.

In addition, the utility model discloses still disclose an application and have above-mentioned bicycle crank structure's chain wheel subassembly. This chain wheel subassembly is owing to use the crank structure who has above-mentioned structure, so can guarantee articulate mechanical properties, can effectively lighten weight again and realize the lightweight, and production efficiency is higher than traditional structure, production mode, and the practicality is strong.

Second embodiment

The present embodiment mainly discloses a chain wheel assembly to which the bicycle crank structure described in the first embodiment is applied, and the chain wheel assembly includes a left crank, a right crank, a center shaft and a chain wheel, wherein the left crank and the right crank are respectively mounted at two ends of the center shaft, the chain wheel is mounted on the center shaft or the left crank, one end of each of the left crank and the right crank is provided with a mounting hole 301 for connecting the center shaft, the other end of each of the left crank and the right crank is provided with a pedal, a plurality of concave cavities 304 are formed between the mounting hole 301 and the pedal along the axial direction of the mounting hole 301, and at least two reinforcing ribs 302 extending along the length direction of the left crank and the right crank are respectively formed through the concave cavities 304.

The structure of the crank is the same as that of the crank in the first embodiment, and the left crank and the right crank are both provided with sealing plates 4 for closing the concave cavity 304, so that dust and mud are prevented from being accumulated in the concave cavity 304, and the crank is convenient to clean and maintain.

As a first preferable scheme of the cavity 304 in this embodiment, only one cavity 304 is disposed on each of the left crank and the right crank, the cavity 304 extends along the length direction thereof to form two reinforcing ribs 302 on two sides of the left crank and the right crank, and the sealing plate 4 closes the cavity to form a hollow box-shaped structure.

As a second preferred solution of the cavity 304 in the present embodiment, N cavities 304 are provided on each of the left crank and the right crank, where N is 2, 3, 4, and 5, the N cavities 304 are arranged in a row along the length direction thereof, so that two reinforcing ribs 302 are formed on both sides of the left crank and the right crank, and N-1 rib plates are formed between the two reinforcing ribs 302. The two reinforcing ribs 302 with the structure can improve the mechanical properties such as strength, toughness and the like through the rib plate effect.

As shown in fig. 3-6, as a further improvement of the present solution, the chain wheel includes a spoke 2 and a gear ring 1 detachably mounted on the spoke 2, the outer side of the gear ring 1 is provided with a plurality of driving teeth 101 around the axis, and the center of the spoke 2 is provided with a mounting structure for connecting a crank or a middle shaft.

In the use, the chain wheel is fixed in together through the mounting structure at 2 centers of spoke and subassemblies such as crank, axis, if the tooth portion of chain wheel takes place wearing and tearing when needing to be changed, only need dismantle outer lane partial ring gear 1 change can, need not like the general dismantlement crank isotructure of traditional structure, improved convenience and the efficiency that the change was dismantled to the tooth portion. And, can select for use the material in a flexible way as required in the in-process of production ring gear 1 and spoke 2, avoided traditional chain wheel because of the many problems that the material problem brought, can be under the condition of guaranteeing intensity, toughness and the rigidity of spoke 2 and alleviate the quality, need not to consider its wearability, simultaneously under the prerequisite of guaranteeing intensity, the toughness of tooth portion, focus on guaranteeing its wearability, realize high strength, high rigidity, high toughness, high wearability and the lightweight of chain wheel through combining together both. The ring gear 1 in this embodiment is preferably made of steel, so that it has excellent strength, wear resistance and toughness, and may be made of other materials with good wear resistance. The spoke 2 is preferably made of aluminum alloy, so that the spoke has the advantages of light weight while having enough strength, toughness and rigidity, and can also be made of light materials such as carbon fiber and magnesium alloy.

This ring gear 1 accessible rivet riveting or screw connection or interference fit etc. direct mount are in the spoke 2 outside, but considering that tooth portion can receive very big shearing force when chain drive of chain wheel drive bicycle, above-mentioned mounting means can cause great load to rivet or screw etc. in view of this, as the further improvement of this scheme, the outside of spoke 2 is provided with a plurality of spoke convex parts 201 around the axle center, the inboard of ring gear 1 corresponds spoke convex part 201 and is provided with a plurality of lock concave position 103, spoke convex part 201 can be pressed in the lock concave position 103 along the axial direction.

Thus, when the gear ring 1 is subjected to shearing acting force, force transmission and dispersion can be realized through the matching of the spoke convex part 201 and the buckling concave part 103, the force transmission between the gear ring 1 and the spoke 2 is avoided only through the action of a rivet or a screw, and the improvement of working stability, connection strength and reliability is facilitated. Meanwhile, the spoke convex part 201 moves along the axial direction and is assembled with the buckling concave part 103, and the spoke convex part mainly bears shearing acting force in the working process of the crankset, and almost no acting force along the axial direction exists, so that the assembling mode has strong working reliability and stability.

As shown in the drawings, in the present embodiment, a plurality of convex forming concave positions 206 are formed in the circumferential side of the spoke 2 along the axial direction, a spoke convex portion 201 is formed between two adjacent convex forming concave positions 206, and a gear ring convex portion 102 matching with the convex forming concave position 206 is formed between two adjacent fastening concave positions 103. The depth of the convex part forming concave position 206 is matched with the thickness of the gear ring 1, so that the side wall of the buckling concave position 103 is completely attached to the spoke convex part 201, the contact area is ensured, and the bearing capacity is improved. In order to ensure the arrangement of the male-forming recesses 206, the thickness of the spoke 2 must be greater than that of the ring gear 1, but since it is made of an aluminum alloy, the increase in weight is minimal, but at the same time this increase in thickness contributes to the strength of the spoke 2. In the structure, a limit plate 207 abutting against the end surface of the ring gear 1 or the end surface of the ring gear convex part 102 is formed between two adjacent spoke convex parts 201, when the ring gear 1 is assembled, the limit plate 207 can be used for installation and positioning, and a rivet or screw installation hole is conveniently arranged between the ring gear convex part 102 and the limit plate 207, so that the connection and the fixation of the two are realized.

As a further improvement of this solution, one side or both sides of the spoke protrusion 201 are provided with a protruding structure protruding relative to the root thereof, and one side or both sides of the fastening concave position 103 are provided with a concave structure matching with the protruding structure. As shown in the figure, the convex structure may be a fan-shaped structure formed by matching the spoke convex portion 201 and the ring gear convex portion 102, or a convex block-shaped structure or a convex hull may be formed on the side surface of the spoke convex portion 201, and a concave structure matched with the convex block-shaped structure or the convex hull may be formed in the fastening concave portion 103.

Thus, the spoke protrusion 201 can form an outward-expanding structure with a narrow root and a wide outer side through the protruding structure, and after the tooth part is subjected to tangential acting force, the acting force is mainly borne by the protruding structure and the inward-concave structure, so that the rivet only bears a small part of force, and the rivet mainly axially fixes the gear ring 1 and the spoke 2. And because the plurality of convex-concave structures are arranged along the circumferential direction, the acting force of the chain is uniformly distributed on the circumference, so that the strength required by rivet connection is greatly reduced, and the bearing capacity of the whole tooth part is also greatly improved. When dragging ring gear 1 at the chain effort simultaneously, can realize preventing dragging through concave-convex structure, effectively improve ring gear 1 and spoke 2's joint strength.

As shown in the figure, as a further improvement of the present solution, the spoke 2 includes an inner spoke ring 204 and an outer spoke ring 202 which are coaxially distributed, and a plurality of spokes 203 which are arranged between the inner spoke ring 204 and the outer spoke ring 202 and are used for connecting the two, the convex part forming concave part 206 is arranged on one side surface of the outer spoke ring 202, and the other side surface of the outer spoke ring 202 is provided with a first weight-reducing groove. A mounting structure for connecting a crank or a central axle is provided on the inner spider 204. In this way, since the inner and outer spokes 204, 202 are secured by the spokes 203, material usage can be reduced while reducing weight.

Preferably, the first lightening grooves in the present embodiment include annular lightening grooves 209 located inside the convex forming concave 206 and tooth-shaped lightening grooves 208 located in a staggered manner from the convex forming concave 206. Meanwhile, in the embodiment, a second lightening slot 210 is arranged on the same side surface of the spoke 203 as the first lightening slot, and the spoke 203 is provided with a spoke rib 211 extending along the length direction of the spoke 203 on two sides of the spoke 203 through the second lightening slot 210. The tooth-shaped lightening grooves 208 are communicated with the annular lightening grooves 209, and the second lightening grooves 210 are also communicated with the annular lightening grooves 209, so that the edge positions of the openings formed between two adjacent spokes 203 form reinforcing ribs 212 connected with the spokes 211, and as shown in the figure, the reinforcing ribs 212 and the spokes 211 form a closed enclosing plate structure. In this way, the weight of the spoke 2 can be effectively reduced by the first lightening grooves provided after reasonably avoiding the convex portion forming concave portions 206 and the second lightening grooves 210 provided on the spokes 203 on the same side, which contributes to the realization of light weight. And although the thickness of the spoke 2 is reduced by the arrangement of the first weight-reducing grooves and the second weight-reducing grooves 210, the strength and the toughness can be increased through the enclosing plate structure, the shearing strength is improved, and therefore the overall strength, the toughness and the like are not greatly influenced. For the parts such as the chain wheel, the structure realizes the perfect combination of strength, rigidity, toughness, wear resistance and light weight.

In the actual production process, the inner spoke ring 204, the outer spoke ring 202 and the spokes 203 are integrally formed, and the first weight-reducing grooves and the second weight-reducing grooves 210 can be formed by integrally forming the inner spoke ring 204, the outer spoke ring 202 and the spokes 203 or by milling according to the actual processing difficulty.

As shown, the mounting structure includes an inner spline 205 disposed at the center of the inner rim 204 and a plurality of mounting holes distributed around the axial direction and disposed on the inner rim 204. The mounting hole site can include a mounting hole site used for connecting and fixing with the crank, and can also include a mounting hole site used for mounting a disk. And the internal spline 205 is used to mate with the bottom bracket of the bicycle for mounting.

In addition, the shapes and sizes of the inner rim 204, the outer rim 202 and the spokes 203 can be set reasonably as required in the actual production process, and as shown in the figure, the spokes 203 in this embodiment are bent in the axial direction of the spoke 2, so that the inner rim 204 and the outer rim 202 are offset in the axial direction. The chain wheel structure in the embodiment is not only suitable for a bicycle chain wheel or a flywheel, but also suitable for all chain transmission or gear transmission, and has a wide application range.

Third embodiment

The present embodiment mainly uses the second embodiment, except that the inner ring edge formed by the ring gear convex part 102 and the fastening concave part 103 on the ring gear 1 in the present embodiment is provided with the inclined surface 104 at one end near the bottom of the convex part forming concave part 206, so that when the ring gear 1 is installed on the spoke 2 along the axial direction, the installation can be facilitated through the guiding of the inclined surface 104, and the assembly efficiency is improved. The absence of the bevel 104 at the opposite end of the ring gear 1 facilitates the seamless abutment between this end face and the spoke 2.

Fourth embodiment

The second embodiment is mainly used in the present embodiment, except that the circumferential diameter of the limiting plate 207 is larger than the circumferential diameter of the outermost end of the spoke protrusion 201, so as to form a circle of extension wall formed outside the spoke protrusion 201 as shown in fig. 3, increase the contact area between the limiting plate 207 and the ring gear 1, and improve the assembly strength and stability.

Fifth embodiment

The present embodiment mainly uses the second embodiment, except that only the first lightening grooves are provided in the present embodiment, and the second lightening grooves 210 are not provided, so as to be suitable for the case that the spokes 203 are small in size.

Sixth embodiment

The present embodiment mainly uses the second embodiment, but the difference is that the left crank and the crankset are fixedly connected to form an integrated crankset.

Seventh embodiment

The second embodiment is mainly used in the present embodiment, and the difference is that a circle of fastening holes are arranged at the inner circumferential position of the gear ring 1 in the present embodiment, a sinking platform adapted to the thickness of the gear ring 1 is arranged at the outer circumferential position of the outer spoke ring 202, an installation column matched with the fastening holes is arranged on the sinking platform, the installation column is inserted into the fastening holes to realize fixation, and then a rivet or screw installation hole is arranged between the installation column and the fastening hole to realize fixation, or the installation column and the fastening hole are in interference fit.

Eighth embodiment

The present embodiment is mainly the first embodiment, except that the N cavities 304 in the present embodiment are arranged in M rows, M being 2, 3, 4, along the length direction of the crank body 3, so as to form M-1 reinforcing ribs 302.

The above embodiments are merely preferred embodiments of the present invention, and other embodiments are also possible. Equivalent modifications or substitutions may be made by those skilled in the art without departing from the spirit of the invention, and such equivalent modifications or substitutions are intended to be included within the scope of the claims set forth herein.

Claims (10)

1. The utility model provides a bicycle crank structure, includes crank main part (3), the one end of crank main part (3) is provided with mounting hole (301), the other end is provided with the pedal, mounting hole (301) are used for connecting the bicycle axis, a serial communication port, crank main part (3) are provided with a plurality of cavities (304) of the axial indent along mounting hole (301) between mounting hole (301) and pedal, crank main part (3) are formed with at least two strengthening ribs (302) that extend along the length direction of crank main part (3) through a plurality of cavities (304).

2. A bicycle crank arrangement according to claim 1, further comprising at least one sealing plate (4), said sealing plate (4) being mounted on the crank body (3) for closing the cavity (304).

3. A bicycle crank structure according to claim 2, characterized in that the cavity (304) is provided with one and extends along the length of the crank body (3) so that two ribs (302) are formed on both sides of the crank body (3), and the sealing plate (4) closes the cavity (304) to form a hollow box-like structure.

4. A bicycle crank structure according to claim 3, wherein the reinforcing rib (302) is provided with a dovetail groove, and the sealing plate (4) is provided with a clamping leg (401) on the peripheral side and riveted in the dovetail groove by the clamping leg (401).

5. A chain wheel assembly, characterized in that, is provided with the bicycle crank structure of any one of claims 1 to 4, still includes left crank, right crank, axis and chain wheel, left crank and right crank are installed respectively in the both ends of axis, the chain wheel is installed on axis or left crank, left crank and right crank's one end all is provided with mounting hole (301) for connecting the axis, the other end all is provided with the pedal, and left crank and right crank are provided with along a plurality of cavities (304) of the axial indent of mounting hole (301) between mounting hole (301) and pedal, left crank and right crank are formed with at least two strengthening ribs (302) that extend along self length direction respectively through cavity (304).

6. A dental disc assembly according to claim 5, wherein the left and right cranks are each provided with a sealing plate (4) for closing the cavity (304).

7. The dental disc assembly according to claim 6, wherein each of the left crank and the right crank is provided with a cavity (304), the cavity (304) extends along the length direction of the cavity so that two reinforcing ribs (302) are formed on two sides of the left crank and the right crank, and the sealing plate (4) closes the cavity to form a hollow box-shaped structure.

8. A chain wheel assembly according to claim 5, characterized in that the chain wheel comprises a spoke (2) and a gear ring (1) detachably mounted on the spoke (2), a plurality of driving teeth (101) are arranged on the outer side of the gear ring (1) around the axis, and a mounting structure for connecting a crank or a middle shaft is arranged at the center of the spoke (2).

9. A dental disc assembly according to claim 8, wherein the spoke (2) is provided with a plurality of spoke protrusions (201) on the outer side around the axis, the ring gear (1) is provided with a plurality of fastening recesses (103) on the inner side corresponding to the spoke protrusions (201), and the spoke protrusions (201) can be pressed into the fastening recesses (103) along the axial direction.

10. A die-disc assembly according to claim 8, characterized in that the spokes (2) are made of aluminium alloy, carbon fibre or magnesium alloy and the ring gear (1) is made of steel.