Double-helix crank structure and bicycle

Abstract

The double-helix crank structure comprises a crank and a pair of rocker arms, the tail ends of the two rocker arms are hinged through a root shaft so that the two rocker arms can relatively rotate with the root shaft as the axis, the root shaft is used for being fixedly connected with a bicycle frame of the bicycle, and the head ends of the rocker arms are used for being hinged to pedals through shafts; the middle of the crank is fixedly connected with a main shaft, the main shaft is used for being rotationally connected with a frame of a bicycle and used for being in transmission connection with a driving wheel of the bicycle, the main shaft is parallel to a root shaft, the two ends of the crank are symmetrically and rotationally connected with the two rocker arms in a sliding mode, and the sliding direction is arranged in the length direction of the rocker arms; when the crank is perpendicular to any rocker arm, the included angle between the crank and the other rocker arm is an acute angle. The problem that a dead zone exists in an existing bicycle driving mechanism can be solved.

Description

Technical Field

[0001] The invention relates to the technical field of bicycle driving structures, and in particular to a double-helical crank structure and a bicycle. Background Art

[0002] At present, the conventional bicycle driving structure includes a rocker arm, a main shaft and a pedal. The tail end of the rocker arm is connected to the main shaft, and the pedal shaft is hinged to the head end of the rocker arm. By stepping on the pedal, the rocker arm can be driven to rotate around a circular trajectory with the main shaft as the axis, and then the main shaft is driven to rotate, so that the rotating main shaft drives the driving gear to rotate, thereby driving the driving wheel to rotate.

[0003] The bicycle with the above structure has the following problems: (1) The upper and lower dead point torques are very small, and when the foot is at the dead point, it will feel like "there is no strength to use"; (2) The optimal force angle is only about 120°; (3) The foot works for only one-third of the time, and the rest is useless work.

[0004] Logically, it seems that increasing the length of the cranks will allow cyclists to output more power when riding. However, in actual riding, longer cranks mean longer foot travel, which will make cyclists more tired. Some cyclists even replace shorter cranks to achieve faster speeds, and increase their pedaling frequency to improve their performance in competitions. Therefore, how to eliminate the dead zone of the drive mechanism is an urgent problem to be solved. Summary of the invention

[0005] The purpose of the present invention is to provide a double-helical crank structure to solve the problem of dead zone in the existing bicycle driving mechanism.

[0006] The present invention is achieved through the following technical solutions:

[0007] A double helical crank structure comprises: a pair of rocker arms, the tail ends of the two rocker arms are hinged by a root axis so that the two rocker arms can rotate relative to each other with the root axis as the axis, the root axis is used to be fixedly connected to the frame of the bicycle, and the head end of the rocker arm is used to hinge a pedal; a crank, the middle part of the crank is fixedly connected with a main shaft, the main shaft is used to be rotatably connected to the frame of the bicycle and to be connected to the driving wheel of the bicycle, the main shaft is arranged parallel to the root axis, the two ends of the crank are symmetrically connected to the two rocker arms for sliding and rotation, and the sliding direction is arranged along the length direction of the rocker arm; when the crank is perpendicular to any one of the rocker arms, the angle between the crank and the other rocker arm is an acute angle.

[0008] Optionally, the crank includes a first crank and a second crank, and the first crank and the second crank have the same shape; the tail ends of the first crank and the second crank are respectively connected to the main shaft, so that the rotation plane of the first crank is arranged parallel to the rotation plane of the second crank; an installation gap is reserved between the tail end of the first crank and the tail end of the second crank along the axial direction of the main shaft, and the installation gap is used to clamp the driving gear of the bicycle; the head end of the first crank and the head end of the second crank are respectively connected to the two rocker arms in a sliding and rotational manner.

[0009] Optionally, the first crank and the second crank are collinear and arranged in opposite directions.

[0010] Optionally, the rocker arm is provided with a slide groove along the length direction; a slide shaft is provided at the end of the crank, the slide shaft is arranged parallel to the main shaft, and the two slide shafts are respectively slidably and rotatably connected to the two slide grooves.

[0011] Optionally, the sliding shaft rotation sleeve is provided with a bearing, and the outer wall of the bearing is slidably matched with the corresponding sliding groove.

[0012] Optionally, the rocker arm includes a transmission section and a force section, and the transmission section and the force section are both straight; one end of the transmission section is fixedly connected to the force section, and the angle between the transmission section and the force section is an obtuse angle; the slide groove is opened in the transmission section and extends along the length direction of the transmission section; the root shaft is set at one end of the transmission section away from the force section; the end of the force section away from the transmission section is used for the shaft hinge pedal; when one of the transmission sections is perpendicular to the crank, the angle between the other transmission section and the crank is an acute angle.

[0013] Optionally, when the first transmission segment is perpendicular to the crank, the force-applying segment connected to the second transmission segment is arranged in parallel with the first transmission segment.

[0014] Optionally, the ratio of the length of the crank to the length of the transmission section is ≤1:1.4.

[0015] Optionally, the root shaft is connected to a support arm, and the support arm is used to be fixedly connected to the frame of the bicycle so that the point where the root shaft is located is tangent to the lowest point of the driving gear of the bicycle.

[0016] A bicycle comprises: a frame, the frame is provided with a driving wheel and a driven wheel; any one of the above-mentioned double-helix crank structures, the root shaft is fixedly connected to the frame, the main shaft is rotatably connected to the frame, the main shaft is coaxially fixedly connected with a driving gear, the driving gear is drivingly connected to the driving wheel, and the head end of the rocker arm is hinged with a pedal.

[0017] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0018] The present invention provides a double-helix crank structure, which is provided with a pair of rocker arms, and the rear ends of the two rocker arms are hinged by an axle, and a main shaft and a crank are provided at the same time, so that the two ends of the crank are symmetrically connected with the two rocker arms for sliding and rotation. Compared with the existing single-shaft (only main shaft) type driving mechanism, one more shaft is added, and the movement trajectory of the rocker arm is changed, so that the end of the rocker arm provided with the pedal only makes an up and down reciprocating swing at a smaller circular angle (acute angle), so that any angle is an optimal force-generating angle when force is exerted, and work can always be done smoothly, there is no dead point or dead zone, and no useless work is done; and, as the rocker arm reciprocates up and down at a smaller (acute angle) circular angle, the crank will rotate at a large angle (circle), effectively increasing the angular velocity of the main shaft, which is equivalent to increasing the angular velocity of the tire, that is, improving the pedaling efficiency; through the mutual cooperation of the above-mentioned features, the double-helix crank structure can effectively solve the problem of dead zones in the existing bicycle driving mechanism. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings:

[0020] Figure 1 A schematic diagram of a double helical crank structure provided by an embodiment of the present invention;

[0021] Figure 2 A schematic diagram of a double helical crank structure provided by an embodiment of the present invention with the driving gear removed;

[0022] Figure 3 A schematic diagram of a rocker arm with a double helical crank structure provided by an embodiment of the present invention;

[0023] Figure 4 A schematic diagram of a bicycle provided in accordance with an embodiment of the present invention.

[0024] Marks and corresponding parts names in the attached drawings:

[0025] 1-frame; 2-driving wheel; 3-driven wheel; 4-driving gear; 10-rocker arm; 101-slideway; 102-transmission section; 103-force section; 11-root shaft; 12-support arm; 20-crank; 201-first crank; 202-second crank; 21-spindle; 22-sliding shaft. DETAILED DESCRIPTION

[0026] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments and drawings. The exemplary embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0027] Please refer to Figures 1 to 3 The embodiment of the present invention provides a double-helix crank structure, comprising a pair of rocker arms 10, the tail ends of the two rocker arms 10 are hinged by a root shaft 11, so that the two rocker arms 10 can rotate relative to each other with the root shaft 11 as the axis, the root shaft 11 is used to be fixedly connected to the frame of the bicycle, and the head end of the rocker arm 10 is used to hinge the pedal; the second comprises a crank 20, the middle part of the crank 20 is fixedly connected with a main shaft 21, the main shaft 21 is used to be rotatably connected to the frame of the bicycle, and is used to be connected to the driving wheel of the bicycle, the main shaft 21 is arranged parallel to the root shaft 11, and the two ends of the crank 20 are symmetrically connected to the two rocker arms 10 for sliding and rotation, and the sliding direction is arranged along the length direction of the rocker arm 10; when the crank 20 is perpendicular to any one of the rocker arms 10, the angle between the crank 20 and the other rocker arm 10 is an acute angle.

[0028] The double helical crank 20 structure provided in the present embodiment is provided with a pair of rocker arms 10, and the tail ends of the two rocker arms 10 are hinged by a shaft 11, and a main shaft 21 and a crank 20 are provided at the same time, so that the two ends of the crank 20 are symmetrically connected to the two rocker arms 10 for sliding and rotation. Compared with the existing single-axis (only main shaft 21) type driving mechanism, one shaft 11 is added, and the motion trajectory of the rocker arm 10 is changed, so that the end of the rocker arm 10 provided with the pedal only makes an up-and-down reciprocating swing at a relatively small circumferential angle (acute angle), so that any angle is a better angle for exerting force when exerting force, and work can always be done smoothly, there is no dead point or dead zone, and no useless work is done; and, as the rocker arm 10 reciprocates up and down at a relatively small (acute angle) circumferential angle, the crank 20 will rotate at a large angle (circle), which effectively increases the angular velocity of the main shaft 21, which is equivalent to increasing the angular velocity of the tire, that is, improving the pedaling efficiency; through the mutual cooperation of the above-mentioned features, the double helical crank 20 structure can effectively solve the problem of dead zones in the existing bicycle driving mechanism.

[0029] In order to further explain the specific structure of the crank 20, the crank 20 includes a first crank 201 and a second crank 202, and the first crank 201 and the second crank 202 have the same shape; the tail ends of the first crank 201 and the second crank 202 are respectively connected to the main shaft 21, so that the rotation plane of the first crank 201 and the rotation plane of the second crank 202 are arranged in parallel; an installation gap is reserved between the tail ends of the first crank 201 and the tail ends of the second crank 202 along the axial direction of the main shaft 21, and the installation gap is used to clamp the driving gear of the bicycle; the head end of the first crank 201 and the head end of the second crank 202 are respectively connected to the two rocker arms 10 in a sliding and rotational manner.

[0030] Through the above arrangement, the two ends of the crank 20 are not in the same plane, but in two parallel planes. Since the two rocker arms 10 are hinged, the two must be in a stacked state, so the ends of the two are not in the same plane, and there is a gap between the two rocker arms 10 for setting the driving gear, so the distance between the two cannot be ignored. In order to enable the two ends of the crank 20 to be effectively close to and connected with the two rocker arms 10, the use of a split method can effectively solve this problem and make room for the setting spacing of the driving gear.

[0031] In order to improve the rationality of the structure of the crank 20 and reduce the length of the first crank 201 and the second crank 202 while ensuring the structural performance, the first crank 201 and the second crank 202 are collinear and arranged in opposite directions.

[0032] In order to further explain the specific structure of the sliding and rotating connection between the rocker arm 10 and the crank 20, the rocker arm 10 is provided with a slide groove 101 along the length direction; a sliding shaft 22 is provided at the end of the crank 20, and the sliding shaft 22 is arranged parallel to the main shaft 21, and the two sliding shafts 22 are respectively connected to the two slide grooves 101 for sliding and rotation.

[0033] Through the above arrangement, the sliding shaft 22 is inserted into the sliding groove 101 , so that it can slide along the sliding groove 101 and rotate smoothly at the same time, thereby realizing the sliding and rotating connection between the crank 20 and the rocker arm 10 .

[0034] It should be noted that the slide groove 101 penetrates the rocker arm 10 along the thickness direction of the rocker arm 10 to provide a sufficient insertion depth for the slide shaft 22 .

[0035] In order to improve the smoothness of the sliding and rotating cooperation between the sliding shaft 22 and the sliding groove 101 , the sliding shaft 22 is rotatably sleeved with a bearing, and the outer wall of the bearing is slidably matched with the corresponding sliding groove 101 .

[0036] In order to further explain the specific structure of the rocker arm 10, the rocker arm 10 includes a transmission section 102 and a force section 103, and the transmission section 102 and the force section 103 are both straight lines; one end of the transmission section 102 is fixedly connected to the force section 103, and the angle between the transmission section 102 and the force section 103 is an obtuse angle; the slide groove 101 is opened in the transmission section 102 and extends along the length direction of the transmission section 102; the root shaft 11 is set at one end of the transmission section 102 away from the force section 103; the end of the force section 103 away from the transmission section 102 is used for the shaft hinge pedal; when one of the transmission sections 102 is perpendicular to the crank, the angle between the other transmission section 102 and the crank is an acute angle.

[0037] Through the above arrangement, the rocker arm 10 is divided into a transmission section 102 and a force application section 103, both of which are straight lines, and the angle between them is an obtuse angle, so as to extend the length of the rocker arm 10 while ensuring the distance between the ends of the two rocker arms 10, so as to facilitate the setting of pedals and facilitate the user to step up and down reciprocatingly; by limiting that when one of the transmission sections 102 is perpendicular to the crank 20, the angle between the other transmission section 102 and the crank 20 is an acute angle, the force application efficiency is further optimized.

[0038] It should be noted that the connection between the transmission section 102 and the force-applying section 103 is splined, so that the angle between the two can be adjusted according to actual needs, thereby adjusting the height of the force-applying section 103 from the ground.

[0039] In order to further improve the rationality of the structure, when the first transmission segment 102 is perpendicular to the crank, the force-applying segment 103 connected to the second transmission segment 102 is arranged in parallel with the first transmission segment 102 .

[0040] In order to further optimize the force application efficiency, the length ratio of the crank 20 to the transmission section 102 is ≤1:1.4.

[0041] In order to further facilitate the user's pedaling force, the root shaft 11 is connected to a support arm 12, and the support arm 12 is used to be fixedly connected to the frame of the bicycle so that the point where the root shaft 11 is located is tangent to the lowest point of the driving gear of the bicycle.

[0042] Through the above arrangement, firstly, by limiting the setting height of the root shaft 11, the relative heights of the root shaft 11 and the main shaft 21 have a certain height difference, so that the root shaft 11 is lower than the setting height of the main shaft 21, so that the tangent line of the root shaft 11 and the lowest point of the driving gear is horizontal, so that the rocker arm 10 is always switched between the upward and horizontal states, and will not tilt downward, so that the user's feet can always have better force conditions and will not have the feeling of stepping on air; and because the position of the beam body of the frame is generally fixed, for example, the beam body of the rear wheel generally has to pass through the wheel axle of the rear wheel horizontally, there is a high probability that there will be a height difference (distance difference) between it and the root shaft 11, and the support arm 12 is provided to compensate for this part of the distance difference, so that the root shaft 11 has a fixedly connected structural fulcrum.

[0043] Please refer to Figure 4 The embodiment of the present invention further provides a bicycle, comprising: a frame 1, wherein the frame 1 is provided with a driving wheel 2 and a driven wheel 3; a second double-helix crank structure comprising any one of the above, wherein the root shaft 11 is fixedly connected to the frame 1, the main shaft 21 is rotationally connected to the frame 1, the main shaft 21 is coaxially fixedly connected with a driving gear 4, the driving gear 4 is transmission-connected to the driving wheel 2, and the head end of the rocker arm 10 is hinged with a pedal.

[0044] Through the above arrangement, the user can drive the two rocker arms 10 to alternately reciprocate up and down by stepping on the pedals up and down, thereby driving the crank 20 to rotate continuously, thereby driving the main shaft 21 to rotate continuously, thereby driving the driving gear 4 to rotate continuously, and thereby driving the driving wheel 2 to rotate continuously, so that the bicycle can be driven.

[0045] It should be noted that, in the present embodiment, the driving gear 4 is connected to the driving wheel 2 by a chain. Specifically, the driving wheel 2 is coaxially connected with a plurality of driven gears, and the driven gears are connected to the driving gear 4 by a chain transmission. When the driving gear 4 rotates, it drives the driven gears to rotate through the chain, thereby driving the driving wheel 2 to rotate.

[0046] It should be noted that the connection methods of the positions not mentioned in the above-mentioned bicycle are all connected using existing technologies. Those skilled in the art can clearly realize several connections not mentioned, which do not belong to the invention points of this application and will not be described again here.

[0047] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A double helical crank structure, characterized in that: include: A pair of rocker arms (10), the rear ends of the two rocker arms (10) being hinged by a root shaft (11) so that the two rocker arms (10) can rotate relative to each other about the root shaft (11), the root shaft (11) being used for being fixedly connected to a bicycle frame, and the head ends of the rocker arms (10) being used for hinged pedals; A crank (20), wherein a main shaft (21) is fixedly connected to the middle of the crank (20), and the main shaft (21) is used for rotationally connecting with the frame of the bicycle and for transmissionly connecting with the driving wheel of the bicycle, and the main shaft (21) is arranged parallel to the root shaft (11), and the two ends of the crank (20) are symmetrically connected to the two rocker arms (10) for sliding and rotation, and the sliding direction is arranged along the length direction of the rocker arms (10); When the crank (20) is perpendicular to any one of the rocker arms (10), the angle between the crank (20) and the other rocker arm (10) is an acute angle.

2. The double helical crank structure according to claim 1, characterized in that: The crank (20) comprises a first crank (201) and a second crank (202), wherein the first crank (201) and the second crank (202) have the same shape; The tail ends of the first crank (201) and the second crank (202) are respectively connected to the main shaft (21), so that the rotation plane of the first crank (201) and the rotation plane of the second crank (202) are arranged in parallel; An installation gap is reserved between the tail end of the first crank (201) and the tail end of the second crank (202) along the axial direction of the main shaft (21), and the installation gap is used to clamp a driving gear of the bicycle; The head end of the first crank (201) and the head end of the second crank (202) are respectively connected to the two rocker arms (10) in a sliding and rotational manner.

3. The double helical crank structure according to claim 2, characterized in that: The first crank (201) and the second crank (202) are arranged in the same line and in opposite directions.

4. The double helical crank structure according to any one of claims 1 to 3, characterized in that: The rocker arm (10) is provided with a slide groove (101) along the length direction; A sliding shaft (22) is provided at the end of the crank (20), and the sliding shaft (22) is arranged parallel to the main shaft (21). The two sliding shafts (22) are respectively connected to the two sliding grooves (101) in a sliding and rotational manner.

5. The double helical crank structure according to claim 4, characterized in that: The sliding shaft (22) is rotatably sleeved with a bearing, and the outer wall of the bearing is slidably matched with the corresponding sliding groove (101).

6. The double helical crank structure according to claim 5, characterized in that: The rocker arm (10) comprises a transmission section (102) and a force-applying section (103), and both the transmission section (102) and the force-applying section (103) are linear; One end of the transmission section (102) is fixedly connected to the force-applying section (103), and the angle between the transmission section (102) and the force-applying section (103) is an obtuse angle; The slide groove (101) is provided in the transmission section (102) and extends along the length direction of the transmission section (102); The root shaft (11) is arranged at one end of the transmission section (102) away from the force-applying section (103); One end of the force-applying section (103) away from the transmission section (102) is used for pivoting the pedal; When one of the transmission sections (102) is perpendicular to the crank (20), the angle between the other transmission section (102) and the crank (20) is an acute angle.

7. The double helical crank structure according to claim 6, characterized in that: When the first transmission segment (102) is perpendicular to the crank, the force-applying segment (103) connected to the second transmission segment (102) is arranged parallel to the first transmission segment (102).

8. The double helical crank structure according to claim 7, characterized in that: The ratio of the length of the crank (20) to the length of the transmission section (102) is ≤1:1.

4.

9. The double helical crank structure according to claim 1, characterized in that: The root shaft (11) is connected with a support arm (12), and the support arm (12) is used for fixed connection with the frame of the bicycle so that the point where the root shaft (11) is located is tangent to the lowest point of the driving gear of the bicycle.

10. A bicycle, characterized in that: include: A vehicle frame (1), wherein the vehicle frame (1) is provided with a driving wheel (2) and a driven wheel (3); The double helical crank structure as described in any one of claims 1 to 9, wherein the root shaft (11) is fixedly connected to the frame (1), the main shaft (21) is rotationally connected to the frame (1), the main shaft (21) is coaxially fixedly connected to a driving gear (4), the driving gear (4) is transmission-connected to the driving wheel (2), and the front end of the rocker arm (10) is hinged with a pedal.

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