TW202120380A - Bicycle with composite chain wheel composed of four elliptical arcs capable of improving the riding efficiency even when two feet exert uneven forces - Google Patents

Abstract

The invention includes a front wheel, a rear wheel, a frame, and a transmission system. The front and rear wheels are pivotally installed on the frame. The transmission system includes a crank, a front chain wheel, a rear chain wheel, and a chain. The crank is coaxially connected to the front chain wheel and then pivotally installed between the front and rear wheels. The rear chain wheel is coaxially connected to the rear wheel, and the chain is wound around the front and rear chain wheels. The front chain wheel includes two first ellipse parts and two second ellipse parts, which are staggered, opposed and connected to each other. The sum of the angles of the two first ellipse parts and two second ellipse parts is 360 degrees. The two ellipse parts have a half long axis and a half short axis, respectively, and their outer edges have G1 teeth and G2 teeth, respectively, where G2 is a positive integer, and G1 is a positive integer greater than G2. Therefore, the invention has the following advantages: the composite chain wheel can improve the riding efficiency even when two feet exert uneven forces, and the composite chain composed of four elliptical arcs is an innovative design.

Description

Bicycle with compound sprocket composed of four elliptical arcs

The present invention relates to a bicycle with a compound sprocket composed of four elliptical arcs, especially a compound sprocket that can improve the riding efficiency of uneven force exerted on both feet, and a compound composed of four elliptical arcs. The sprocket is an unprecedented revolutionary design for a bicycle with a compound sprocket composed of four elliptical arcs.

Referring to Figure 8, the related structure of the bicycle drive system mainly includes a frame 91, a chain 92, a front sprocket 93, a rear sprocket 94, a crank 95 and two pedals 96. Wherein, the two pedals 96 are pivoted at both ends of the crank 95, and the center of the crank 95 is a central shaft portion 951, which is coaxially fixed with the front sprocket 93; the chain 92 is wound around the front sprocket 93 And the rear sprocket 94; when simplifying the description here, the transmission and other components are ignored. It is known that the front sprocket is round (ie a round sprocket). When a user is riding a bicycle, the left and right casters will be pedaled in turn. Assuming that the force exerted by the left and right feet is even, there is no problem of uneven force . Please refer to Figure 9. This is a schematic diagram of a user's left foot force (left foot area P1) and right foot force (right foot area P2) resulting in uneven crank torque, where the crank angle is between 0 degrees and Between 180 degrees is the right foot, the peak value of its crank torque is about 37 Newton meters (Nm), and the crank angle between 180 degrees and 360 degrees is the left foot, and its peak value of crank torque is about 22 Newton meters (Nm), far Below the right foot. In particular, regardless of whether it is used to step on with the right foot or the left foot, the stepping force of the dominant foot will be higher than that of the non-dominant foot. In this case, when riding, there will be obvious uneven force problems. . Therefore, it is necessary to develop new technologies to solve the above shortcomings and problems.

； 該第二橢圓部概呈1/4個橢圓形，而具有一第二半長軸及一第二半短軸，第二半長軸等於該第一半長軸，該第二半短軸等於該第一半短軸；該第二橢圓部之外緣係具有G2個該齒部；並具有一第二偏心率(ε2)，其係被定義為：

； 其中，G2係為正整數，G1係為大於G2之正整數。 本發明之上述目的與優點，不難從下述所選用實施例之詳細說明與附圖中，獲得深入瞭解。 茲以下列實施例並配合圖式詳細說明本發明於後：The object of the present invention is to provide a bicycle with a compound sprocket composed of four sections of elliptical arcs, which also has a compound sprocket that can improve the riding efficiency of uneven force exerted on both feet, and a compound composed of four sections of elliptical arcs The type sprocket has unprecedented revolutionary design and other advantages. In particular, the problem to be solved by the present invention is that whether it is used to step on with the right foot or the left foot, the stepping force of the dominant foot will be higher than that of the non-dominant foot. In this case, when riding, There are obvious problems such as uneven force. The technical means to solve the above problems is to provide a bicycle with a compound sprocket composed of four elliptical arcs, which includes: a front wheel; a rear wheel; a frame with a head tube, a handle and a front fork assembly , A central axis pivot part and a rear fork part; the handle and front fork assembly are pivoted on the head tube part, the front wheel is pivoted on the handle and front fork assembly, the rear wheel is pivoted on the rear On the fork; a transmission system with a crank, a front sprocket, a rear sprocket and a chain; the crank system has a central shaft and a pair of pedals, the central shaft and the front sprocket are coaxially pivoted At the pivotal part of the central axis; the pair of pedals are pivoted at both ends of the crank and are 180 degrees to each other; the rear sprocket and the rear wheel are coaxially fixed, and the chain is wound around the front sprocket and the rear Between the sprockets; wherein, the front sprocket is a composite sprocket, which has a rotation axis, two first ellipse parts and two second ellipse parts, the two first ellipse parts and the two second ellipse parts Is centered on the axis of rotation, staggered, opposed to each other and connected to form the front sprocket; in addition, the two first elliptical parts both have a first arc angle, and the two second elliptical parts are both The system has a second arc line angle, the first arc line angle is greater than the second arc line angle, and the sum is 180 degrees, so that the outer edge of the front sprocket is 360 degrees; the first ellipse The part is roughly 1/4 ellipse, and has a first semi-major axis and a first semi-minor axis. The outer edge of the first ellipse has G1 teeth; and has a first eccentricity (ε1 ), which is defined as:

; The second ellipse is roughly 1/4 ellipse, and has a second semi-major axis and a second semi-minor axis, the second semi-major axis is equal to the first semi-major axis, the second semi-minor axis It is equal to the first semi-minor axis; the outer edge of the second ellipse has G2 teeth; and it has a second eccentricity (ε2), which is defined as:

; Among them, G2 is a positive integer, and G1 is a positive integer greater than G2. The above-mentioned objects and advantages of the present invention can be easily understood from the detailed description of the following selected embodiments and the accompanying drawings. Hereinafter, the present invention will be described in detail with the following examples and drawings:

。 該第二橢圓部423概呈1/4個橢圓形，而具有一第二半長軸a2及一第二半短軸b2，第二半長軸a2等於該第一半長軸a1，該第二半短軸b2等於該第一半短軸b1。該第二橢圓部423之外緣係具有G2個該齒部42A；並具有一第二偏心率(ε2)，其係被定義為：

。 其中，G2係為正整數，G1係為大於G2之正整數。 實務上，G1較佳為大於等於9之正整數，G2較佳為大於等於8之正整數。 該第一角度θ1係介於95度至105度之間。 該第二角度θ2係介於75度係85度之間 該第一橢圓部422之外緣係具有9個齒部42A。 該第二橢圓部423之外緣係具有8個齒部42A。 該第一偏心率ε1之較佳範圍係介於05~0.8之間。 該第二偏心率ε2之較佳範圍係介於0.05~0.15之間。 在此要特別說明的部分是，為了改善圓形鏈輪所產生之左、右腳不平均施力情況，可藉由調整在非慣用腳區段鏈輪的齒數來增加此區段所帶動之鏈輪半徑，進而形成半橢圓形鏈輪。兩不同形狀之鏈輪相接處為橢圓形之半短軸，因而橢圓形之半短軸與圓形半徑會相等。半長軸為左腳施力區段，藉此產生較大扭矩。橢圓形偏心率之上限以不超過0.6為主，關於橢圓形之偏心率，如第3圖所示，X軸上之長軸為2a，Y軸上之短軸為2b，兩焦點距離為2εa。 其中，偏心率ε之定義為

。

。 a為半長軸；b為半短軸；

為旋轉角度。 而「設計一齒盤」之複合式鏈輪(如第4圖所示)、「設計二齒盤」之複合式鏈輪(如第5圖所示)與「圓形」之傳統鏈輪三者，提供三位受測者進行檢測之平均輸入功率、平均輸出功率、曲柄角度之比較，分別如第6A、第6B、第7A及7B圖所示。 參閱下表一，其係本案之實施例一(如第4圖所示)，簡稱「設計一齒盤」，其中： 該第一橢圓部422之外緣係具有9個齒部42A； 該第二橢圓部423之外緣係具有8個齒部42A； 該第一偏心率ε1係為0.6； 該第二偏心率ε2係為0.1。 同樣參閱下表一，關於本案之實施例二(如第5圖所示)，簡稱設計二齒盤」，其中： 該第一橢圓部422之外緣係具有10個齒部42A； 該第二橢圓部423之外緣係具有8個齒部42A； 該第一偏心率ε1係為0.74； 該第二偏心率ε2係為0.1。 而比對基礎為傳統之圓形鏈盤，簡稱「圓形齒盤」。 (表一) 齒盤種類 輸入功率(W) 輸入功率(W) 效率(%) 圓形齒盤 18.56 13.91 74.94 設計一齒盤 13.07 10.37 79.34 設計二齒盤 9.41 7.80 82.85 由表一可知，設計一齒盤之效率為79.34％，較圓形齒盤的效率74.94為優。至於設計二齒盤之效率為82.85，比設計一齒盤更優。 綜上所述，本發明之優點及功效可歸納如下： [1] 複合式鏈輪可提高兩腳施力不平均之騎乘效率。由於許多人之慣用腳(例如為右腳)之踩踏力與非慣用腳(例如為左腳)之踩踏力不同，可能影響騎乘速度。而本發明可巧妙的運用複合式鏈輪之設計，來解決這個問題，並能提高騎乘之整體效率。故，複合式鏈輪可提高兩腳施力不平均之騎乘效率。 [2] 四段橢圓弧線組成之複合式鏈輪為前所未見之革命性設計。西元1868年法國有人發明第一輛用鏈條傳動後輪的安全型自行車，而自行車之前鏈輪在近一百多年來均設計為圓形，本案打破此設計理念，為一極大之創新與突破。故，四段橢圓弧線組成之複合式鏈輪為前所未見之革命性設計。 以上僅是藉由較佳實施例詳細說明本發明，對於該實施例所做的任何簡單修改與變化，皆不脫離本發明之精神與範圍。Referring to the first, second and third figures, the present invention is a bicycle with a compound sprocket composed of four elliptical arcs, which includes: a front wheel 10. One rear wheel 20. A frame 30 has a head pipe portion 31, a handle and front fork assembly 32, a central shaft pivot portion 33 and a rear fork portion 34. The handle and front fork assembly 32 is pivoted on the head pipe portion 31, the front wheel 10 is pivoted on the handle and front fork assembly 32, and the rear wheel 20 is pivoted on the rear fork portion 34. A transmission system 40 has a crank 41, a front sprocket 42, a rear sprocket 43 and a chain 44. The crank 41 has a central shaft portion 411 and a pair of pedals 412; the central shaft portion 411 and the front sprocket 42 are coaxially pivoted on the central shaft pivot portion 33; the pair of pedals 412 are pivoted on two of the crank 41 Ends, and are 180 degrees to each other. The rear sprocket 43 and the rear wheel 20 are coaxially fixed; the chain 44 is wound between the front sprocket 42 and the rear sprocket 43. Wherein, the front sprocket 42 is a composite sprocket, which has a rotation axis 421, two first elliptical parts 422, and two second elliptical parts 423, the two first elliptical parts 422 and the two second elliptical parts 423 is centered on the rotation axis 421, staggered, facing each other and connected to form the front sprocket 42. In addition, the two first ellipse portions 422 each have a first arc angle θ1, the two second ellipse portions 423 both have a second arc angle θ2, and the first arc angle θ1 is greater than The sum of the second arc angle θ2 is 180 degrees, so that the outer edge of the front sprocket 42 is 360 degrees. The first elliptical part 422 is roughly 1/4 ellipse, and has a first semi-major axis a1 and a first semi-minor axis b1. The outer edge of the first elliptical part 422 has G1 teeth 42A; And has a first eccentricity (ε1), which is defined as:

. The second ellipse 423 is roughly 1/4 ellipse, and has a second semi-major axis a2 and a second semi-minor axis b2. The second semi-major axis a2 is equal to the first semi-major axis a1, and the second semi-major axis a2 is equal to the first semi-major axis a1. The second semi-minor axis b2 is equal to the first semi-minor axis b1. The outer edge of the second ellipse 423 has G2 teeth 42A; and has a second eccentricity (ε2), which is defined as:

. Among them, G2 is a positive integer, and G1 is a positive integer greater than G2. In practice, G1 is preferably a positive integer greater than or equal to 9, and G2 is preferably a positive integer greater than or equal to 8. The first angle θ1 is between 95 degrees and 105 degrees. The second angle θ2 is between 75 degrees and 85 degrees. The outer edge of the first elliptical portion 422 has 9 tooth portions 42A. The outer edge of the second elliptical portion 423 has 8 tooth portions 42A. The preferred range of the first eccentricity ε1 is between 05 and 0.8. The preferred range of the second eccentricity ε2 is between 0.05 and 0.15. The part to be specifically explained here is that in order to improve the uneven force exerted by the left and right feet caused by the round sprocket, the number of teeth of the sprocket in the non-dominant foot section can be adjusted to increase the amount of the sprocket driven by this section. The sprocket radius, which in turn forms a semi-elliptical sprocket. The elliptical semi-minor axis where two sprockets of different shapes meet, so the semi-minor axis of the ellipse and the radius of the circle will be equal. The semi-major axis is the force exerting section of the left foot, thereby generating greater torque. The upper limit of the elliptical eccentricity should not exceed 0.6. Regarding the eccentricity of the ellipse, as shown in Figure 3, the long axis on the X axis is 2a, the short axis on the Y axis is 2b, and the distance between the two focal points is 2εa . Among them, the eccentricity ε is defined as

.

. a is the semi-major axis; b is the semi-minor axis;

Is the rotation angle. And the compound sprocket of "design one chainring" (as shown in Figure 4), the compound sprocket of "design two chainring" (as shown in figure 5) and the traditional sprocket of "round" three For comparison, the average input power, average output power, and crank angle of the three test subjects are provided, as shown in Figures 6A, 6B, 7A, and 7B, respectively. Refer to Table 1 below, which is the first embodiment of the present case (as shown in Figure 4), referred to as "design a sprocket", in which: the outer edge of the first elliptical portion 422 has 9 tooth portions 42A; The outer edge of the two elliptical portions 423 has 8 tooth portions 42A; the first eccentricity ε1 is 0.6; the second eccentricity ε2 is 0.1. Also refer to Table 1 below. Regarding the second embodiment of the present case (as shown in Figure 5), it is referred to as "designing a two-toothed disc", in which: the outer edge of the first elliptical portion 422 has 10 tooth portions 42A; the second The outer edge of the ellipse 423 has 8 teeth 42A; the first eccentricity ε1 is 0.74; the second eccentricity ε2 is 0.1. The basis of the comparison is the traditional round chain disc, referred to as "round chainring". (Table I) Type of chainring Input power (W) Input power (W) effectiveness(%) Round chainring 18.56 13.91 74.94 Design a chainring 13.07 10.37 79.34 Design two chainrings 9.41 7.80 82.85 It can be seen from Table 1 that the efficiency of designing a chainring is 79.34%, which is better than the efficiency of a circular chainring of 74.94. As for the efficiency of designing two chainrings, it is 82.85, which is better than designing one chainring. In summary, the advantages and effects of the present invention can be summarized as follows: [1] The compound sprocket can improve the riding efficiency of uneven force applied to both feet. Since the pedaling force of the dominant foot (for example, the right foot) of many people is different from the pedaling force of the non-dominant foot (for example, the left foot), the riding speed may be affected. The present invention can cleverly use the design of the composite sprocket to solve this problem and improve the overall efficiency of riding. Therefore, the compound sprocket can improve the riding efficiency of uneven force exerted on both feet. [2] The compound sprocket composed of four elliptical arcs is a revolutionary design that has never been seen before. In 1868, someone in France invented the first safety bicycle with a chain-driven rear wheel. The chain wheels of bicycles were designed to be round in the past 100 years. This case breaks this design concept and is a great innovation and breakthrough. . Therefore, the compound sprocket composed of four elliptical arcs is a revolutionary design that has never been seen before. The above is a detailed description of the present invention based on a preferred embodiment, and any simple modifications and changes made to the embodiment will not depart from the spirit and scope of the present invention.

10: Front wheel 　　　　　　　　　 20: rear wheel 30, 91: Frame 　　　　　 　 　 31: Head Tube 32: Handle and front fork assembly 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 33: Central axis pivot 34: Rear fork 　　　 　　　 40: Transmission system 41, 95: crank 411, 951: Axis 412, 96: Pedal 42, 93: front chain wheel 421: Rotating axis 422: The first ellipse 423: The second ellipse 　 　 　 　 　 　 　 　 　 　 　 42A: Tooth 43, 94: Rear chain wheel 44, 92: chain θ1: Angle of the first arc line θ2: second arc angle a1: The first half of the long axis a2: the first semi-major axis b1: The first semi-short axis b2: second semi-minor axis P1: Left foot area P2: Right foot area

Figure 1 is a schematic diagram of the present invention Figure 2 is a schematic diagram of the sprocket before the present invention Figure 3 is a schematic diagram of an elliptical nodal curve Figure 4 is the specification drawing of the sprocket before the semi-major axis of the present invention is 72.5616 Figure 5 is the specification drawing of the sprocket before the semi-major axis of the present invention is 80.2931 Figure 6A is a graph of the average input power of the design of a chainring of the present invention Figure 6B is a graph of the average output power of the design of a chainring of the present invention Figure 7A is a graph of the average input power of the design of the two-tooth disk of the present invention Figure 7B is a graph of the average output power of the designed two-toothed disk of the present invention Figure 8 is a schematic diagram of a known bicycle Figure 9 is a graph showing the uneven crank torque caused by the difference between the user's left and right foot forces

40: Transmission system

41: crank

412: Pedal

42: front sprocket

421: Rotation Axis

422: The first ellipse

423: The second ellipse

42A: Tooth

44: chain

θ 1: the angle of the first arc

θ 2: The second arc angle

a1: the first semi-major axis

a2: the first semi-major axis

b1: the first semi-minor axis

b2: second semi-minor axis

Claims (4)

A bicycle with a composite sprocket composed of four elliptical arcs, which includes: a front wheel; a rear wheel; a frame with a head tube, a handle and a front fork assembly, a central axis pivot and a The rear fork; the handle and the front fork assembly are pivoted on the head tube, the front wheel is pivoted on the handle and the front fork assembly, the rear train is pivoted on the rear fork; a transmission system, It has a crank, a front sprocket, a rear sprocket and a chain; the crank has a central shaft portion and a pair of pedals, the central shaft portion and the front sprocket are coaxially pivoted on the central shaft pivoting portion; the The pair of pedals are pivoted at both ends of the crank and are 180 degrees mutually; the rear sprocket and the rear wheel are coaxially fixed, and the chain is wound between the front sprocket and the rear sprocket; wherein, the The front sprocket is a composite sprocket, which has a rotation axis, two first ellipse parts and two second ellipse parts, the two first ellipse parts and the two second ellipse parts are centered on the rotation axis , Staggered, opposite to each other and connected to form the front sprocket; in addition, the two first elliptical parts each have a first arc line angle, and the two second ellipse parts both have a second arc line The angle of the first arc line is greater than the angle of the second arc line, and the sum is 180 degrees, so that the outer edge of the front sprocket is 360 degrees; the first ellipse is approximately a 1/4 ellipse It has a first semi-major axis and a first semi-minor axis, and the outer edge of the first ellipse has G1 teeth; and has a first eccentricity (ε1), which is defined as:

; The second ellipse is roughly 1/4 ellipse, and has a second semi-major axis and a second semi-minor axis, the second semi-major axis is equal to the first semi-major axis, the second semi-minor axis It is equal to the first semi-minor axis; the outer edge of the second ellipse has G2 teeth; and it has a second eccentricity (ε2), which is defined as:

; Among them, G2 is a positive integer, and G1 is a positive integer greater than G2. A bicycle with a compound sprocket composed of four elliptical arcs as described in item 1 of the scope of patent application, of which: The first angle is between 95 and 105 degrees; The second angle is between 75 and 85 degrees; The first eccentricity ε1 is between 0.5 and 0.8. The second eccentricity ε2 is between 0.05 and 0.15. A bicycle with a compound sprocket composed of four elliptical arcs as described in item 2 of the scope of patent application, of which: The outer edge of the first ellipse has 9 teeth; The outer edge of the second ellipse has 8 teeth; The first eccentricity ε1 is 0.6; The second eccentricity ε2 is 0.1. A bicycle with a compound sprocket composed of four elliptical arcs as described in item 2 of the scope of patent application, in which: The outer edge of the first ellipse has 10 teeth; The outer edge of the second ellipse has 8 teeth; The first eccentricity ε1 is 0.74; The second eccentricity ε2 is 0.1.

Images