Novel crank middle shaft connecting structure

Abstract

The utility model provides a novel crank middle shaft connecting structure which comprises a crank and a middle shaft, a fixing groove used for locking the middle shaft is formed in the connecting end of the crank, the middle shaft is inserted into the fixing groove to be fixed so as to rotate along with the crank, and the fixing groove is provided with a large-diameter section and a small-diameter section which are adjacently connected from inside to outside. First press-fit teeth are distributed on the inner wall of the small-diameter section of the fixing groove in the circumferential direction, second press-fit teeth matched with the first press-fit teeth are arranged on the portion, close to the connecting end, of the outer wall of the middle shaft in the circumferential direction, guide-in teeth are arranged on the end face of the connecting end of the middle shaft in the circumferential direction, and the diameter of the small-diameter section of the fixing groove is larger than that of the portion, located at the guide-in teeth, of the middle shaft. And the diameter is smaller than that of the middle shaft and located at the second press-fit teeth. According to the utility model, the connecting end of the middle shaft can be easily pressed and matched into the fixing groove by utilizing the leading-in teeth, and the middle shaft is fixed by utilizing the matching of the first press-fit teeth and the second press-fit teeth, so that the space utilization rate is improved, and the service lives of the middle shaft and the crank are prolonged.

Description

TECHNICAL FIELD

[0001] The utility model relates to a bicycle accessory technical field, concretely relates to a novel crank axle connecting structure. BACKGROUND

[0002] The bicycle is also called as the footboard or the bicycle, and is a kind of green environmental protection traffic tool, which is a vehicle that people drive wheel rotation to move by treading pedal, is mainly composed of vehicle body part, transmission part, action part and safety device, and in each component of bicycle, except some small bearings, mainly have three bearings, i.e.

[0003] The existing crank axle detachable connecting mode is that a fixing hole for locking axle is formed on the connecting end of crank, and first press-fit teeth are arranged on the inner wall of fixing hole, and then second press-fit teeth matched with first press-fit teeth are formed on the outer wall of axle connecting end, thereby constituting locking type fixing structure.

[0004] However, because interference fit is needed between axle and crank, so the size of second press-fit teeth on axle is greater than the size of first press-fit teeth on crank, and thus it can make second press-fit teeth be pressed skew after press fit of axle and crank.If interference fit between second press-fit teeth on axle and first press-fit teeth on crank is skew, it can cause axle and crank to be loose after long time riding, so the existing connecting mode has limitation. UTILITY MODEL CONTENTS

[0005] The utility model is carried out in order to solve the above-mentioned problem, and the purpose is to provide a novel crank axle connecting structure.

[0006] The utility model provides a novel crank axle connecting structure has such characteristics, include: crank and axle, the fixed groove that is used for locking axle is set up on the connecting end of crank, axle is inserted into fixed groove and is fixed to rotate with the crank, the fixed groove is stepped, has the big diameter section and small diameter section of adjacent joint from inside to outside, the big diameter section of fixed groove diameter is greater than the diameter of axle, the inner wall of small diameter section of fixed groove is equipped with first pressure fit tooth along the circumference, first pressure fit tooth is constituted by first arc groove and first arc convex that a plurality of side ends are connected in sequence, the outer wall of axle and is close to the connecting end place is equipped with second pressure fit tooth that coordinates first pressure fit tooth along the circumference, second pressure fit tooth is constituted by second arc groove and second arc convex that a plurality of side ends are connected in sequence, the end face of axle connecting end is equipped with lead -in tooth along the circumference, wherein, the diameter of small diameter section of fixed groove is greater than the diameter of axle and is located at lead -in tooth, is less than the diameter of axle and is located at second pressure fit tooth.

[0007] In the novel crank axle connecting structure provided by the utility model, the lead-in tooth can be composed of a plurality of arc surfaces, and each arc surface is located at an end of a second arc groove or a second arc convex.

[0008] In the novel crank axle connecting structure provided by the utility model, each arc surface and the second arc groove or the second arc convex are connected in a smooth transition.

[0009] Effects of the utility model

[0010] According to the novel crank axle connecting structure, the diameter of the small diameter section of the fixed groove is greater than the diameter of the axle at the lead-in tooth and less than the diameter of the axle at the second pressure fit tooth, so that the connecting end of the axle can be easily pressed into the fixed groove by the lead-in tooth, and the axle can be fixed by the cooperation of the first pressure fit tooth and the second pressure fit tooth, thereby improving the space utilization, simplifying the fixing structure between the axle and the crank, and prolonging the service life of the axle and the crank. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 is a structural schematic diagram of the utility model;

[0012] Figure 2 is Figure 1 is an enlarged view of A in

[0013] Figure 3 is a partial sectional view of the utility model;

[0014] Figure 4 is Figure 3 is an enlarged view of B in

[0015] MARKING OF THE DRAWINGS:

[0016] 1, crank; 11, fixed groove; 12, first press-fit tooth; 2, shaft; 21, second press-fit tooth; 22, guide tooth. DETAILED DESCRIPTION

[0017] In order to make the technical means, creative features, purposes and effects of the utility model easy to understand, the following embodiments are combined with the drawings to specifically describe the utility model.

[0018] EMBODIMENT

[0019] Figure 1 is a structural schematic diagram of the utility model, Figure 2 is Figure 1 is an enlarged view of A in Figure 3 is a partial sectional view of the utility model, Figure 4 is Figure 3 is an enlarged view of B in

[0020] As Figures 1 to 4 shown, the embodiment provides a novel crank shaft connecting structure, comprising: crank 1 and shaft 2. Wherein, the connecting end of crank 1 is provided with fixed groove 11 for locking shaft 2, and shaft 2 is inserted into fixed groove 11 to be fixed and rotate with crank 1.

[0021] In the embodiment, fixed groove 11 is stepped, having a large diameter section and a small diameter section adjacent and connected along the circumference from inside to outside, the diameter of the large diameter section of fixed groove 11 is larger than the diameter of shaft 2, and the inner wall of the small diameter section of fixed groove 11 is provided with first press-fit tooth 12 along the circumference, which is composed of a plurality of first arc-shaped grooves and first arc-shaped protrusions connected in sequence along the side end.

[0022] In the embodiment, the outer wall of shaft 2 and close to the connecting end is provided with second press-fit tooth 21 matched with first press-fit tooth 12 along the circumference, which is composed of a plurality of second arc-shaped grooves and second arc-shaped protrusions connected in sequence along the side end, and the end face of the connecting end of shaft 2 is provided with guide tooth 22 along the circumference.

[0023] In the embodiment, the diameter of the small diameter section of fixed groove 11 is larger than the diameter of shaft 2 at guide tooth 22 and smaller than the diameter of shaft 2 at second press-fit tooth 21, so that the connecting end of shaft 2 can be easily pressed into fixed groove 11 by guide tooth 22.

[0024] In the embodiment, the first arc-shaped groove is matched with the second arc-shaped protrusion, and the first arc-shaped protrusion is matched with the second arc-shaped groove, so that after shaft 2 is inserted into fixed groove 11, it is matched with first press-fit tooth 12 and second press-fit tooth 21 to realize the fixation of shaft 2 and prevent relative rotation.

[0025] In the embodiment, the lead-in tooth 22 is composed of a plurality of arc surfaces, each of which is located at the end of a second arc-shaped groove or a second arc-shaped protrusion.

[0026] In the embodiment, each arc surface is connected to the second arc-shaped groove or the second arc-shaped protrusion in a smooth transition.

[0027] Effects of the embodiment

[0028] According to the novel crankshaft connecting structure, the diameter of the small-diameter section of the fixing groove is greater than the diameter of the crankshaft at the lead-in tooth and smaller than the diameter of the crankshaft at the second press-fitting tooth, so the connecting end of the crankshaft can be easily pressed into the fixing groove by the lead-in tooth, and the crankshaft is fixed by the cooperation of the first press-fitting tooth and the second press-fitting tooth, thereby improving the space utilization, simplifying the fixing structure between the crankshaft and the crank, and prolonging the service life of the crankshaft and the crank.

[0029] The above embodiment is a preferred case of the utility model, and does not limit the protection scope of the utility model.

Claims

1. A novel crank shaft connecting structure, comprising a crank and a shaft, a fixing groove for locking the shaft is formed on the connecting end of the crank, the shaft is inserted into the fixing groove and fixed so as to rotate with the crank, characterized in that: the fixing groove is stepped, having a large-diameter section and a small-diameter section which are adjacently connected from inside to outside, the diameter of the large-diameter section of the fixing groove is larger than the diameter of the shaft, the inner wall of the small-diameter section of the fixing groove is circumferentially provided with first press-fitting teeth, the first press-fitting teeth are composed of a plurality of first arc-shaped grooves and first arc-shaped protrusions which are sequentially connected by side ends, the outer wall of the shaft and close to the connecting end is circumferentially provided with second press-fitting teeth which are matched with the first press-fitting teeth, the second press-fitting teeth are composed of a plurality of second arc-shaped grooves and second arc-shaped protrusions which are sequentially connected by side ends, the end face of the connecting end of the shaft is circumferentially provided with guide teeth, wherein the diameter of the small-diameter section of the fixing groove is larger than the diameter of the shaft at the guide teeth and smaller than the diameter of the shaft at the second press-fitting teeth.

2. The novel crank shaft connecting structure according to claim 1, characterized in that: wherein the guide teeth are composed of a plurality of arc-shaped surfaces, each of the arc-shaped surfaces is located at the end of a second arc-shaped groove or a second arc-shaped protrusion.

3. The novel crank shaft connecting structure according to claim 2, characterized in that: wherein each of the arc-shaped surfaces and a second arc-shaped groove or a second arc-shaped protrusion is connected by smooth transition.

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