A clutch mechanism and gearbox for a bicycle speed changing system

Abstract

The invention relates to a clutch mechanism and a gearbox of a bicycle speed change system, wherein the clutch mechanism comprises a clutch shaft, a clutch gear and a cam; the cam is relatively rotatably arranged in the clutch shaft; the clutch gear is arranged on the clutch shaft; and also comprises a trigger claw; when shifting gears, the cam rotates under the driving of an external force, the head end of the trigger claw slides toward a base circle along the large circle outline of the cam, and when reaching the base circle, the clutch gear contacts the ends of a plurality of trigger claws, so that the clutch gear moves together with the clutch shaft; the clutch can withstand the pedaling torque of a heavy rider, the clutch action will be smoother, the gear shifting will be easier, the "excessive" size constraint of a traditional clutch is eliminated, the disadvantages of a traditional small-volume clutch are overcome, and no obvious performance defects will be generated, so the reliability is high; the cam structure design is simple, the process requirements are not high, and the manufacturing cost is low.

Description

Technical Field

[0001] The present invention relates to the technical field of clutches, and more particularly to a clutch mechanism and a gearbox of a bicycle speed changing system. Background Art

[0002] The gearbox of a multi-speed bicycle allows the cyclist to choose the appropriate transmission ratio according to physical strength and road conditions, thereby helping the human body maintain the pedaling frequency corresponding to the maximum power output, which is especially important for competition. The clutch is usually the core component of the gearbox. The criteria for evaluating the quality of its design are usually: reliability, shifting efficiency (especially when the user is pedaling), design complexity, manufacturing cost, processability, and some clutches also consider the size of the idle travel between gears, especially when the torque needs to be transmitted immediately after the gear shift, such as climbing a steep slope.

[0003] The rotary transmission clutch is a mechanism that has only been used in the bicycle field in the last decade, and is mostly used in the field of mid-mounted transmissions. In the case where the size is not strictly restricted, this type of clutch can allow the clutch action to be completed smoothly when the user pedals, which is crucial for the clutch of competitive mountain bikes, because it is related to the operating efficiency in frequent and rapid gear switching. However, the existing clutches of this type are usually small in size, which makes it difficult for the clutch to perform normal actions when the user pedals, and each clutch gear has a small number of ratchet teeth, a small size, and poor load capacity. This type of clutch mechanism is currently being used in the market in a positive trend, and has great potential for improvement.

[0004] US Patent (US9163702) discloses a speed change device and transmission mechanism, in which only one ratchet on the clutch is meshed with any clutch gear, and the size of the ratchet is strictly limited, resulting in the clutch being unable to withstand the pedaling torque of a heavy rider for a long time. In addition, the design of the composite cam in this solution is relatively complex, resulting in a high scrap rate of the composite cam during the processing process, which indirectly increases the product cost. In addition, due to the serious size limitation, the material and matching tolerance requirements of the ratchet and the clutch shaft supporting the ratchet are relatively high, resulting in high costs.

[0005] In summary, the existing rotary transmission clutch has the disadvantages of low reliability, low gear shifting efficiency when pedaling, complex design, poor processability, high manufacturing cost and large pedaling gap between gear shifts, which makes it easy for riders to affect the pedaling rhythm during the gear shifting process due to transmission problems, affecting their competitive performance. Summary of the invention

[0006] The technical problem to be solved by the present invention is that the existing rotary transmission clutch has the disadvantages of low reliability, low gear shifting efficiency when pedaling, complex design, poor processability, high manufacturing cost and large pedaling neutral space between gear shifts. In view of the above-mentioned defects of the prior art, a clutch mechanism and a transmission of a bicycle transmission system are provided.

[0007] The technical solution adopted by the present invention to solve the technical problem is: construct a clutch mechanism of a bicycle speed change system, including a clutch shaft, a clutch gear and a cam; the cam is relatively rotatably arranged in the clutch shaft; the clutch gear is arranged on the clutch shaft; and also includes a trigger claw;

[0008] When shifting gears, the cam rotates under the driving force of external force, and the head end of the trigger claw slides toward the base circle along the large circle outline of the cam, and when reaching the base circle, the clutch gear contacts with the ends of the multiple trigger claws, so that the clutch gear moves together with the clutch shaft.

[0009] Furthermore, a rolling element rolling along the large circular outline of the cam is provided at the front end of the trigger claw; and an elastic element for supporting the rear end of the trigger claw to contact the clutch gear is provided at the rear end of the trigger claw.

[0010] Furthermore, the trigger pawl includes: a pawl and a pawl shaft for positioning the pawl; the pawl shaft and the pawl are connected via a pawl bearing.

[0011] Furthermore, the rolling element comprises a cam follower bearing sliding along the large circular profile of the cam, and a cam follower shaft for positioning the cam follower bearing; and a mounting groove for accommodating the cam follower bearing is provided at the head end of the pawl.

[0012] Furthermore, the elastic member includes: a torsion spring, and a torsion spring shaft for positioning the torsion spring; the long end of the torsion spring contacts the end of the pawl.

[0013] Further, the clutch shaft includes a clutch main shaft; the cam is relatively rotatably arranged in the clutch main shaft; the surface of the clutch main shaft is provided with a first mounting position located on the surface of the clutch main shaft; the first mounting position is composed of one or more slotted holes for accommodating the pawl and the torsion spring; the slotted holes are circumferentially distributed along the surface of the clutch main shaft; the slotted holes are provided with a first groove and a second groove which are cross-arranged with the slotted holes; the pawl rotating shaft is arranged in the first groove; the torsion spring rotating shaft is arranged in the second groove.

[0014] Furthermore, a camshaft for mounting the cam is provided in the clutch shaft; the cam is distributed on the surface of the camshaft.

[0015] Furthermore, the clutch shaft also includes a clutch sleeve arranged on the outside of the clutch shaft; the clutch gear is arranged on the clutch sleeve.

[0016] Furthermore, a plurality of clutch bearings and a clutch rotating shaft are provided in the clutch gear; the clutch rotating shaft passes through the surface of the clutch gear and the clutch bearing, so that the clutch bearing rolls along the surface of the clutch sleeve.

[0017] The present application provides a bicycle gearbox, further comprising a clutch mechanism as described in any one of the above.

[0018] The beneficial effects of the present invention are as follows: the cam rotates relative to the clutch shaft, the head end of the trigger claw slides toward the base circle along the large circle profile of the cam, and when reaching the base circle, the clutch gear contacts the ends of the multiple trigger claws, so that the clutch gear moves with the clutch shaft. When shifting gears, there are multiple trigger claw ends in contact with the clutch gear, and the volume restriction of the trigger claw is relaxed, so that the clutch can withstand the pedaling torque of a heavy rider, the clutch action will be smoother, and the shifting will be easier. The clutch component composition, structure and connection method are redesigned, and the idling angle of the clutch between shifting gears is appropriately reduced. It has the characteristic of small neutral gear when pedaling between gears, gets rid of the "excessive" size constraints of traditional clutches, overcomes the shortcomings of traditional small-volume clutches, and does not produce any obvious performance defects, and has high reliability; the cam structure is simple in design, the process requirements are not high, the manufacturing cost is low, and the shifting efficiency can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the present invention will be further described below in conjunction with the accompanying drawings and embodiments. The drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative work:

[0020] Figure 1 A schematic structural diagram of a clutch mechanism of a bicycle speed change system according to an embodiment of the present invention;

[0021] Figure 2 An exploded schematic diagram of a clutch mechanism of a bicycle speed change system according to an embodiment of the present invention;

[0022] Figure 3 It is a left side schematic diagram of a clutch mechanism of a bicycle speed change system according to an embodiment of the present invention;

[0023] Figure 4a For the embodiment of the present invention Figure 3 The cross-sectional view at AA in the middle Figure 1 ;

[0024] Figure 4b For the embodiment of the present invention Figure 3 The cross-sectional view at AA in the middle Figure 2 ;

[0025] Figure 5 It is a structural schematic diagram of a trigger claw according to an embodiment of the present invention;

[0026] Figure 6 This is a schematic structural diagram of a clutch shaft according to an embodiment of the present invention;

[0027] Figure 7 is a schematic structural diagram of a camshaft according to an embodiment of the present invention;

[0028] Figure 8 A schematic diagram of the structure of a clutch gear according to an embodiment of the present invention;

[0029] Fig. 9 It is a schematic structural diagram of a torsion spring according to an embodiment of the present invention;

[0030] Fig.10 A front schematic diagram of a bicycle gearbox according to an embodiment of the present invention;

[0031] Fig.11 For the embodiment of the present invention Fig.10 The enlarged schematic diagram of point B in the middle;

[0032] Fig.12 A schematic diagram of the back side of a bicycle gearbox according to an embodiment of the present invention;

[0033] Fig.13 For the embodiment of the present invention Fig.12 The enlarged schematic diagram of the center C;

[0034] Fig.14 It is a structural schematic diagram of a bicycle housing according to an embodiment of the present invention;

[0035] Fig.15 The figure is a schematic diagram of the internal structure of a bicycle housing according to an embodiment of the present invention.

[0036] In the figure, 1, clutch shaft; 2, camshaft; 3, clutch sleeve; 4, clutch gear; 11, slotted hole; 12, first groove; 13, second groove; 21, cam; 22, concave position; 23, camshaft small bearing; 24, camshaft large bearing; 25, first retaining spring; 26, second retaining spring; 31, second installation position; 41, clutch bearing; 42, clutch shaft; 43, clutch bearing gasket; 51, pawl; 52, pawl bearing; 53, pawl shaft; 54, pawl axial gasket; 55, pawl radial pad; 61, torsion spring; 62, torsion spring Rotating shaft; 63, torsion spring radial pad; 71, cam follower bearing; 72, cam follower shaft; 81, first gear train module; 82, clutch gear train module; 83, second gear train module; 84, third gear train module; 91, gear box chain; 92, rear hub sprocket; 93, gear box external chain; 94, bicycle rear swing arm; 95, frame front triangle; 511, mounting slot; 811, first sprocket; 812, second gear; 821, first gear; 822, third gear; 831, input sprocket; 841, output sprocket; 842, fourth gear. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the following will be described clearly and completely in combination with the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are partial embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the protection scope of the present invention.

[0038] The preferred embodiment of the present invention is as follows Figure 1 to Figure 2 As shown, a clutch mechanism of a bicycle speed change system is provided, comprising a clutch shaft, a clutch gear 4 and a cam 21; the cam 21 is relatively rotatably arranged in the clutch shaft; the clutch gear 4 is arranged on the clutch shaft; and a trigger claw is also included;

[0039] When shifting gears, the cam 21 rotates under the drive of external force, and the head end of the trigger claw slides toward the base circle along the large circle outline of the cam 21, and when reaching the base circle, the clutch gear 4 contacts the ends of the multiple trigger claws, so that the clutch gear 4 moves together with the clutch shaft.

[0040] The clutch shaft is provided with multiple sets of trigger claws. The relative rotation of the cam 21 and the clutch shaft can be implemented by a variety of clutch actuators, such as a double planetary gear mechanism. When the user performs a gear shift operation, the cam 21 rotates relative to the clutch shaft, and the head end of the trigger claw slides along the large circle outline of the cam 21 toward the base circle, and when reaching the base circle, the end of the trigger claw rises and contacts the clutch gear 4. The trigger claw can withstand the force transmitted from the clutch gear 4 at this time, thereby causing the clutch shaft to move together with the clutch gear 4. The cam 21 is kept relatively still with the clutch shaft by means of the clutch actuator, that is, it rotates in the same direction at the same angular velocity. At the same time, one end of the trigger claw corresponding to the previous gear will leave the base circle of the cam 21 and continue to slide along the large circle outline of the cam 21. The end thereof that cooperates with the clutch gear 4 leaves the clutch gear 4 and is retracted into the clutch shaft. After the gear shift is completed, the clutch gear 4 can be normally meshed with the gears on the upper and lower transmission shafts of the gear transmission.

[0041] By adopting this scheme, the clutch can withstand the pedaling torque of heavyweight riders, the clutch action will be smoother, the gear shifting will be easier, the clutch component composition, structure and connection method are redesigned, the "excessive" size constraints of the traditional clutch are eliminated, the shortcomings of the traditional small-volume clutch are overcome, and no obvious performance defects will occur, and the reliability is high; and one end of the trigger claw moves toward the base circle along the large circle profile of the cam 21, the cam structure design is simple, the process requirements are not high, the manufacturing cost is low, and the gear shifting efficiency can be improved. It overcomes almost all the shortcomings of the traditional small-volume clutch, and no obvious performance defects will occur, and the reliability is high.

[0042] In a further embodiment, a rolling element rolling along the large circular outline of the cam 21 is provided at the front end of the trigger claw; and an elastic element for supporting the end of the trigger claw to contact the clutch gear 4 is provided at the rear end of the trigger claw.

[0043] Specifically, the front end of the trigger claw is in contact with the cam 21 with the help of a rolling element. The rolling element can be regarded as a point on the trigger claw that contacts the cam. From the perspective of the coordination between the trigger claw and the cam 21, the front end of the trigger claw contacts the large circular contour of the cam through this contact point, that is, the process of the trigger claw sliding along the large circular contour of the cam 21 to the base circle is a sliding process. From the perspective of the cam 21 and the rolling element, the rolling of the rolling element along the large circular contour of the cam 21 is only a contact method between the rolling element itself and the cam 21, and is not a contact method between the trigger claw itself and the cam 21. The contact method between the trigger claw and the cam 21 includes but is not limited to the contact method of using the rolling element to roll along the large circular contour of the cam 21.

[0044] When shifting, the cam 21 rotates relative to the clutch shaft under the drive of the clutch actuator. The rolling element at the head end of the trigger claw rolls along the large circle outline of the cam 21 toward the base circle, and when reaching the base circle, the elastic element at the end of the trigger claw lifts the end of the trigger claw, so that the clutch gear 4 contacts with multiple ends of the trigger claws. The trigger claw can now withstand the force transmitted from the clutch gear 4, thereby causing the clutch shaft to move together with the clutch gear 4. The cam 21 must maintain relative stillness with the clutch shaft through its own clutch actuator, that is, rotate in the same direction at the same angular velocity. At the same time, one end of the trigger claw corresponding to the previous gear will leave the base circle of the cam 21 and continue to slide along the large circle outline of the cam 21. The end that cooperates with the clutch gear 4 leaves the clutch gear 4 and is retracted into the clutch shaft. After the shift is completed, the clutch gear 4 can be normally meshed with the gears on the upper and lower transmission shafts of the gear box.

[0045] In the above embodiment, the sizes of all parts such as the cam 21, clutch shaft, clutch gear 4, trigger claw, elastic member and sliding member are deliberately enlarged, so that the radial size of the clutch is appropriately increased, thus getting rid of the "over-constraint" on size of the traditional clutch.

[0046] In a further embodiment, Figure 2 As shown, the clutch shaft member includes a clutch sleeve 3 arranged on the outside of the clutch shaft 1; and a clutch gear 4 is arranged on the clutch sleeve 3.

[0047] In a further embodiment, Figure 8 As shown, a plurality of clutch bearings 41 and a clutch shaft 42 are provided in the clutch gear 4 ; the clutch shaft 42 passes through the surface of the clutch gear 4 and the clutch bearing 41 , so that the clutch bearing 41 rolls along the surface of the clutch sleeve 3 .

[0048] In the above embodiment, the clutch gear 4 is provided with a plurality of mounting positions for mounting the clutch bearing 41, the clutch shaft 42 and the clutch bearing gasket 43. The clutch bearing gasket 43 is located on both sides of the clutch bearing 41, the clutch shaft 42 passes through the clutch bearing gasket 43, the clutch bearing 41 and the clutch bearing gasket 43 in sequence, and the two ends of the clutch shaft 42 are respectively arranged on the mounting positions of the clutch gear 4. The radial positioning of the clutch bearing 41 is achieved by the cooperation of the clutch bearing 41 and the clutch shaft 42, and the axial positioning of the clutch bearing 41 is achieved by the clutch bearing gasket 43. The clutch gear 4 cooperates with the clutch sleeve 3 through the clutch bearing 41 to achieve rolling on the clutch sleeve 3.

[0049] In the above embodiment, a plurality of clutch bearings 41, a clutch shaft 42 and a clutch bearing gasket 43 are provided in the clutch gear 4, that is, the internal space of the clutch gear 4 is relatively large, which can appropriately reduce the idling angle of the clutch between gear shifts while ensuring the strength of the ratchet, and has the characteristic of a small neutral position between gears.

[0050] In another embodiment, the axial positioning of the clutch bearing 41 may also be achieved by direct contact between the clutch bearing 41 and the mounting position of the clutch gear 4 .

[0051] In a further embodiment, Figure 6 As shown, the clutch shaft includes a clutch shaft 1; a cam 21 is relatively rotatably arranged in the clutch shaft 1; a first mounting position is provided on the surface of the clutch shaft 1; the first mounting position is composed of one or more slotted holes 11 for accommodating a pawl 51 and a torsion spring 61; the slotted holes 11 are circumferentially distributed along the surface of the clutch shaft 1; a first groove 12 and a second groove 13 are arranged crosswise with the slotted holes 11 on the slotted holes 11; the pawl shaft 53 is arranged in the first groove 12; and the torsion spring shaft 62 is arranged in the second groove 13.

[0052] The first installation position of the clutch shaft 1 is divided into multiple groups, and a group of first installation positions can be composed of one or more slot holes 11, such as Figure 6 As shown, two slot-shaped holes 11 spaced 180° apart in the circumferential direction form a set of mounting positions. The apertures of the two end faces of the clutch shaft 1 can be set to be one large and one small or the same size. Preferably, the apertures of the two end faces of the clutch shaft 1 are set to be one large and one small. The clutch shaft 1 also includes mounting positions for two or more bearings for matching with parts such as the camshaft 2.

[0053] In a further embodiment, Figure 3 and Figure 5 As shown, the trigger pawl includes: a pawl 51, and a pawl shaft 53 for positioning the pawl 51; the pawl shaft 53 is connected to the pawl 51 through a pawl bearing 52. The clutch shaft 1 has multiple groups of pawls 51, pawl shafts 53 and pawl bearings 52. The pawl 51 is radially positioned in the slotted hole 11 by the pawl shaft 53, and can be rotated in the clutch shaft 1 through the pawl shaft 53 and the pawl bearing 52. A through hole is opened near the middle of the pawl 51 for direct or through the pawl bearing 52 and the pawl shaft 53.

[0054] In the above embodiment, a total of 12 or even more ratchet pawls 51 can be accommodated in the clutch shaft 1, and each gear position also has two or more ratchet pawls 51 engaged with the clutch gear 4. The clutch shaft 1 and the double ratchet pawls 51 are engaged, so that when a rider with a heavy body and a strong pedaling force is riding, the clutch has a higher load-bearing capacity and higher reliability.

[0055] In a further embodiment, Figures 2 to 5 As shown, the rolling element includes a cam follower bearing 71 that slides along the large circular profile of the cam 21, and a cam follower shaft 72 for positioning the cam follower bearing 71; a mounting groove 511 for accommodating the cam follower bearing 71 is provided at the head end of the pawl 51. The cam follower bearing 71 and the cam follower shaft 72 are installed in the mounting groove 511, and the cam follower shaft 72 passes through the middle of the cam follower bearing 71, and its two ends are arranged on the groove wall of the mounting groove 511; so that the cam follower bearing 71 can roll along the large circular profile of the cam 21.

[0056] In a further embodiment, Figure 3 and Fig. 9 As shown, the elastic member includes: a torsion spring 61, and a torsion spring shaft 62 for positioning the torsion spring 61; the long end of the torsion spring 61 contacts the end of the ratchet 51. The torsion spring shaft 62 passes through the torsion spring 61, so that the torsion spring 61 is rotatably connected to the clutch shaft 1. The torsion spring 61 is radially positioned in the slotted hole 11 by the torsion spring shaft 62. The torsion spring 61 can rotate in the slotted hole 11.

[0057] In the above embodiment, the installation direction of the trigger claw and the elastic member in the slot hole 11 or the circumferential orientation thereof can be flexibly arranged through the design of the slot hole 11. Figure 2 In the first installation position corresponding to the first clutch gear 4 and the second clutch gear 4, the relative positions of the first groove 12 and the second groove 13 are positive and negative.

[0058] The pawl 51 has one or more surfaces, preferably two, that match the pawl bearing 52. The pawl 51 has a surface that matches the torsion spring 61. The short end of the torsion spring 61 directly contacts one surface of the slotted hole, and the long end of the torsion spring 61 contacts one surface of the pawl 51. The portion of the torsion spring 61 that contacts the pawl 51 may be L-shaped or other shapes, preferably L-shaped.

[0059] In the above embodiment, during the contact process between the pawl 51 and the clutch bearing 41 in the clutch gear 4, multiple types of rolling friction are involved. Compared with the previous pure sliding friction type, the clutch action of the pawl 51 in this application will be smoother and the gear shifting will be easier.

[0060] In a further embodiment, Figure 7As shown, a camshaft 2 for mounting a cam 21 is provided in the clutch shaft 1; the cams 21 are distributed on the surface of the camshaft 2. A plurality of cams 21 are provided on the surface of the camshaft 2; the camshaft 2 may be a solid or hollow structure, preferably a hollow structure, wherein the apertures of the left and right end faces of the camshaft 2 are preferably one large and one small. The surface of the camshaft 2 includes a plurality of cam follower shafts 72, preferably 5-9, and the contour of each cam follower shaft 72 is composed of a base circle and a circular contour that is concentric with the base circle but has a larger radius, and there is a transition curve between the two circular contours. The above-mentioned base circle is the concave point of the concave position 22 in the figure, and the circular contour that is concentric with the base circle but has a larger radius is the surface of the cam follower shaft 72.

[0061] The camshaft 2 includes two or more bearing installation positions for matching with the clutch shaft 1 and other parts. That is, the camshaft 2 is assembled inside the clutch shaft 1 through the camshaft small bearing 23 and the camshaft large bearing 24. The camshaft small bearing 23 and the camshaft large bearing 24 are positioned axially and radially through the first retaining spring 25, the second retaining spring 26 and the structural features on the clutch shaft 1 and the camshaft 2.

[0062] In a further embodiment, a limiter may be applied on the camshaft 2 to limit the rotation angle of the camshaft 2 around the clutch shaft 1, such as a radially installed screw, etc. The limiter can be used to remind the user that the clutch has been switched to the first and last ends of the gear.

[0063] In the above embodiment, Figure 4a and Figure 4b As shown, the working principle of the clutch mechanism is as follows:

[0064] The relative rotation of the camshaft 2 and the clutch shaft 1 can be realized by a variety of clutch actuators, such as a double planetary gear train mechanism. Among them, the clutch actuator can be driven manually or electrically. When the user performs a gear shift operation, the camshaft 2 rotates relative to the clutch shaft 1, and the cam follower bearing 71 moves along the large circular profile of the cam 21 due to the elastic force of the torsion spring 61. The cam follower bearing 71 to be triggered will move toward the base circle along the large circular profile of the cam 21 (i.e., toward the recessed position 22). Finally, when the cam follower bearing 71 cooperates with the recessed position 22, the pawl 51 is lifted up along the radial direction of the clutch shaft 1 by the torsion spring 61 around the pawl rotating shaft 53, and cooperates with the clutch bearing 41 on the single clutch gear 4. At this time, the pawl 51 can withstand the force transmitted by the clutch bearing 41, thereby causing the clutch shaft 1 to move together with the clutch gear 4. The camshaft 2 is kept relatively still with the clutch shaft 1 through the clutch actuator, that is, it rotates in the same direction at the same angular velocity. At the same time, the pawl 51 corresponding to the previous gear position will move along the base circle of the cam follower shaft 72 to the large circle contour of the cam follower shaft 72 (i.e., leave the concave position 22) because the cam follower bearing 71 moves along the base circle of the cam follower shaft 72, so that the pawl 51 overcomes the elastic force of the torsion spring 61, loosens the fit with the clutch bearing 41, and retracts into the groove hole 11 of the clutch shaft 1. After the gear shift is completed, the clutch gear 4 can be normally meshed with the gears on the upper and lower transmission shafts of the gear box.

[0065] In the above embodiments, the clutch mechanism can be used as the output end of the gear transmission system, or as the intermediate end or the input end (ie, the receiving end) of the power.

[0066] In a further embodiment, the rotating assembly further includes pawl axial washers 54 disposed on both sides of the pawl 51; the pawl shaft 53 passes through the pawl axial washers 54; and a torsion spring radial washer 63 is further disposed in the first groove 12 and the second groove 13. The torsion spring radial washer 63 is used to radially position the torsion spring shaft 62, and the pawl shaft is radially positioned through the pawl radial washer 55. The pawl 51 is axially positioned with the clutch shaft 1 itself through the pawl axial washers 54, and the torsion spring 61 is axially positioned by the clutch shaft 1.

[0067] In another embodiment, both sides of the pawl 51 and both sides of the torsion spring 61 are in contact with the side walls of the slotted hole 11. The pawl 51 and the torsion spring 61 can also be directly positioned by the clutch shaft 1 to achieve axial positioning.

[0068] In a further embodiment, the clutch sleeve 3 is provided with a plurality of second mounting positions 31; the first mounting positions correspond to the second mounting positions 31 one by one. The shapes of the first mounting positions and the second mounting positions 31 are slightly different, and the outer surface of the clutch sleeve 3 is used to cooperate with the clutch bearing 41. The positioning of the clutch sleeve 3 on the clutch shaft 1 is flexibly achieved by means of positioning screws and other mechanisms, such as Kimi screws.

[0069] In another embodiment, the trigger claw can also be replaced by a one-way bearing; the one-way bearing is arranged on the clutch shaft 1; the clutch gear 4 is connected to the one-way bearing through a spline. The clutch device of the one-way bearing is not controlled by the camshaft 2, which can expand the number of gears that the current clutch gear train can be compatible with and simplify the design of the clutch mechanism.

[0070] The present application provides a bicycle gearbox transmission system, such as Figures 1 to 9 As shown, it also includes a clutch mechanism component as any of the above items.

[0071] The camshaft 2 and the clutch shaft 1 are caused to rotate relative to each other through the clutch actuator. When the user performs a gear shift operation, the camshaft 2 rotates relative to the clutch shaft 1. The cam follower bearing 71 moves along the large circular contour of the cam 21 due to the elastic force of the torsion spring 61. The cam follower bearing 71 to be triggered moves toward the base circle along the large circular contour of the cam 21 (i.e., moves toward the recess 22). Finally, when the cam follower bearing 71 cooperates with the recess 22, the pawl 51 is lifted up along the radial direction of the clutch shaft 1 by the torsion spring 61 around the pawl shaft 53, and cooperates with the clutch bearing 41 on the single clutch gear 4. At this time, the pawl 51 can withstand the force transmitted from the clutch bearing 41, thereby causing the clutch shaft 1 to move together with the clutch gear 4. The camshaft 2 is kept relatively still with the clutch shaft 1 through the clutch actuator, i.e., rotates in the same direction at the same angular velocity. At the same time, the pawl 51 corresponding to the previous gear position will move along the base circle of the cam 21 to the large circle outline of the cam 21 (i.e., leave the concave position 22) because the cam follower bearing 71 moves along the base circle of the cam 21, so that the pawl 51 overcomes the elastic force of the torsion spring 61, loosens the fit with the clutch bearing 41, and retracts into the groove hole 11 of the clutch shaft 1. After the gear shift is completed, the clutch gear 4 can be normally meshed with the gears on the upper and lower transmission shafts of the gear box.

[0072] By adopting this solution, the clutch is significantly enlarged in radial dimension, so that the clutch has a higher load-bearing capacity, and it is particularly reliable in application scenarios where the user is heavy and the pedaling force is large. Since the meshing and disengagement process between the ratchet 51 and the clutch gear 4 is mostly of rolling friction type, compared with the pure sliding friction type, the clutch action of the ratchet 51 will be smoother, and the gear shifting will be easier. In addition, by using parts such as the ratchet 51, compared with traditional technology, there is no composite cam part on the camshaft 2, which significantly reduces the complexity of the parts' appearance and effectively reduces the requirements for the processing technology. The design is simple, the processability is good, and the manufacturing cost is low. Furthermore, since the space inside the clutch gear 4 is large, the idling angle of the clutch between gear shifts can be appropriately reduced while ensuring the strength of the ratchet, and it has the characteristic of a small stepping neutral between gears.

[0073] The present application provides a bicycle gearbox, further comprising the clutch mechanism as described above.

[0074] Specifically, a typical 4-axis bicycle gearbox is taken as an example to explain the application of the above clutch mechanism components in detail through a more specific implementation process.

[0075] In this embodiment, combined with Figures 1 to 13 As shown, the first gear train module 81 and the clutch gear train module 82 are the intermediate shaft system or transition shaft system of the entire gearbox transmission system, and the power input and output are respectively constituted by the second gear train module 83 and the third gear train module 84. In this embodiment, except that the gear of the clutch gear train module 82 is connected to the clutch shaft 1 through the ratchet 51 and / or the one-way bearing, the gears of the other gear train modules are fixed together with their shafts, and the fixing method can be bolt fastening or spline and the like.

[0076] Specifically, the user inputs the torque to the second gear train module 83 through the pedals and cranks of the bicycle, and then the input sprocket 831 on the second gear train module 83 transmits the torque to the first sprocket 811 on the first gear train module 81 through the gear box chain 91. In this example, the first gear train module 81 includes 4 gears, which are respectively meshed with the 4 gears of the clutch gear train module 82. Similarly, the 3 gears of the third gear train module 84 are respectively meshed with the other 3 gears of the clutch gear train module 82, that is, the clutch gear train module 82 has a total of 7 gears. Finally, the torque is output to the rear hub sprocket 92 of the rear wheel through the output sprocket 841 on the third gear train module 84, driving the bicycle forward. Among them, the clutch gear train module 82 includes 12 ratchets 51, each two in a group and meshed with one of the clutch gears 4, and also includes a one-way bearing responsible for meshing with the first gear 821.

[0077] When the camshaft 2 in the clutch gear module 82 rotates, the two gears on the clutch gear module 82 corresponding to the two gears on the first gear module 81 and the third gear module 84 must have two groups of pawls or one group of pawls and one one-way bearing (i.e., overrunning clutch) triggered simultaneously at a certain gear position, wherein a group of pawls includes two pawls. Then, the two gears of the clutch gear module 82 corresponding to them are connected to the clutch shaft 1 to transmit torque. In this way, the torque of one gear (e.g., the second gear 812) of the first gear module 81 can be transmitted to the clutch shaft 1 through a gear (e.g., the third gear 822) on the clutch shaft 1, and then a gear (e.g., the first gear 821) on the clutch shaft 1 can transmit the torque to a gear (e.g., the fourth gear 842) on the third gear module 84, and finally the output sprocket 841 on the third gear module 84 transmits the torque through the gearbox external chain 93 (see Fig.14) or a belt or other medium to the rear hub sprocket 92, driving the bicycle forward.

[0078] Furthermore, the relative rotation of the camshaft 2 and the clutch shaft 1 can be realized by a variety of clutch actuators, such as a dual planetary gear train mechanism. Among them, the clutch actuator can be driven manually or electrically. When the user performs a gear shift operation, the camshaft 2 rotates relative to the clutch shaft 1, and the cam follower bearing 71 moves along the large circular profile of the cam 21 due to the elastic force of the torsion spring 61. The cam follower bearing 71 to be triggered will move toward the base circle along the large circular profile of the cam 21 on the camshaft 2 (i.e., move toward the recess 22). Finally, when the cam follower bearing 71 cooperates with the recess 22, the pawl 51 is lifted up along the radial direction of the clutch shaft 1 by the torsion spring 61 around the pawl rotating shaft 53, and cooperates with the clutch bearing 41 on the single clutch gear 4. The pawl 51 can withstand the force transmitted by the clutch bearing 41 at this time, thereby causing the clutch shaft 1 to move with the clutch gear 4. The camshaft 2 is kept relatively still with the clutch shaft 1 through the clutch actuator, that is, it rotates in the same direction at the same angular velocity. The first gear 821 can only cooperate with the one-way bearing (overrunning clutch) to transmit the torque of the clutch shaft 1 .

[0079] Among the three gears of the clutch gear module 82 corresponding to the third gear train module 84, there is a first gear 821 which is assembled with a one-way bearing (overrunning clutch) by a spline or other fixing method. When the two sets of pawls 51 corresponding to two of the gears are not lifted (or triggered), the torque direction applied by the first gear 821 on the one-way bearing to the one-way bearing will be opposite to that when the other two sets of pawls 51 are triggered. With the help of this principle, the one-way bearing can be triggered at this time to transfer the torque on the clutch shaft 1 to the first gear 821, and then transmitted to the fourth gear 842 of the third gear train module 84 by the first gear 821.

[0080] Among them, the above gearbox can be used in Fig.14 In a full-suspension mountain bike housing (i.e. a bike with shock absorbers both front and rear), Fig.15 for Fig.14 perspective view. Fig.10 and Fig.12 The gearbox is sealed in the front triangle 95 of the frame and is integrated with the front triangle 95 of the frame. The shaft of the third gear train module 84 also serves as the pivot point of the bicycle rear swing arm 94, and the gearbox external chain 93 can be arranged very simply between the output sprocket 841 and the rear hub sprocket 92.

[0081] In summary, the gearbox implementation case can generate up to 3x4=12 different transmission ratios. Through reasonable gear ratio and clutch design, the entire gearbox train can generate a transmission ratio sequence that is approximately a geometric sequence, and complete the gear shifting through an electronic or mechanical clutch actuator (i.e., allowing the camshaft 2 to rotate relative to the clutch shaft 1), so that the user can accurately, quickly and easily switch the gear position (transmission ratio) of the transmission system within the transmission ratio range according to the vehicle's driving conditions, maintain the user's own optimal pedaling frequency, achieve the purpose of maximizing the average power output, and help the user achieve better competition results.

[0082] It should be understood that those skilled in the art can make improvements or changes based on the above description, and all these improvements and changes should fall within the scope of protection of the appended claims of the present invention.

Claims

1. A clutch mechanism of a bicycle transmission system, comprising a clutch shaft, a clutch gear and a cam; the cam is relatively rotatably arranged in the clutch shaft; the clutch gear is arranged on the clutch shaft; and the characteristics are: Also included is a trigger claw; When shifting gears, the cam rotates under the driving force of an external force, and the head end of the trigger claw slides along the large circle outline of the cam toward the base circle, and when reaching the base circle, the clutch gear contacts the ends of the plurality of trigger claws, so that the clutch gear moves together with the clutch shaft; The trigger claw head end is provided with a rolling element rolling along the large circular outline of the cam; the trigger claw tail end is provided with an elastic element for supporting the trigger claw tail end to contact the clutch gear; The clutch shaft comprises a clutch shaft, and the clutch shaft comprises a clutch sleeve arranged on the outside of the clutch shaft, and the clutch gear is arranged on the clutch sleeve; a plurality of clutch bearings and a clutch rotating shaft are arranged in the clutch gear; the clutch rotating shaft passes through the surface of the clutch gear and the clutch bearing, so that the clutch bearing rolls along the surface of the clutch sleeve; the end of the trigger claw cooperates with the clutch bearing, and can withstand the force transmitted by the clutch bearing, thereby making the clutch shaft move together with the clutch gear.

2. The clutch mechanism of the bicycle speed change system according to claim 1, characterized in that: The trigger claw comprises: a pawl and a pawl shaft for positioning the pawl; the pawl shaft and the pawl are connected via a pawl bearing.

3. The clutch mechanism of the bicycle speed change system according to claim 2, characterized in that: The rolling element comprises a cam follower bearing sliding along the large circular profile of the cam, and a cam follower shaft used for positioning the cam follower bearing; a mounting groove for accommodating the cam follower bearing is provided at the head end of the pawl.

4. The clutch mechanism of the bicycle speed change system according to claim 2, characterized in that: The elastic member comprises: a torsion spring and a torsion spring shaft for positioning the torsion spring; the long end of the torsion spring contacts the end of the pawl.

5. The clutch mechanism of the bicycle speed change system according to claim 4, characterized in that: The cam is relatively rotatably arranged in the clutch shaft; the surface of the clutch shaft is provided with a first mounting position located on the surface of the clutch shaft; the first mounting position is composed of one or more slotted holes for accommodating the pawl and the torsion spring; the slotted holes are circumferentially distributed along the surface of the clutch shaft; the slotted holes are provided with a first groove and a second groove which are arranged crosswise with the slotted holes; the pawl rotating shaft is arranged in the first groove; the torsion spring rotating shaft is arranged in the second groove.

6. The clutch mechanism of the bicycle speed change system according to claim 5, characterized in that: A camshaft for mounting the cam is disposed in the clutch shaft; the cams are distributed on the surface of the camshaft.

7. A bicycle gearbox, characterized in that: It also includes a clutch mechanism as described in any one of claims 1-6.

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