Speed change system and bicycle

Abstract

The invention belongs to the technical field of bicycle speed control systems, and discloses a speed control system and a bicycle. A planet gear of a planet gear set in the speed control system is connected with a multi-stage driven wheel set to form an amplification wheel set, an inner gear ring is fixed to an outer shell, and a multi-stage driving wheel set is rotationally arranged on a transmission shaft; the multi-stage driven wheel set is rotationally arranged on the output shaft, and a first clutch transmission assembly is arranged between the driven shaft and each stage of the multi-stage driving wheel set. The first limiter can drive the first limiting shaft to enable the gear shifting convex part of the first limiting shaft to abut against the first clutch transmission assembly, so that the transmission shaft is in transmission connection with any stage of the driving wheel set; the second limiting stopper can drive the second limiting shaft to enable the gear shifting protruding part of the second limiting shaft to abut against the second clutch transmission assembly so that the output shaft and the amplification wheel set can be in transmission connection or drive the first limiting shaft to enable the gear shifting protruding part of the first limiting shaft to abut against the third clutch transmission assembly so that the output shaft and the sun wheel can be in transmission connection.

Description

Technical Field

[0001] The present invention relates to the technical field of bicycle speed change systems, and in particular to a speed change system and a bicycle. Background Art

[0002] A Chinese patent with publication number CN113401274A discloses a gearbox in a bicycle mid-shaft, comprising a housing, an input shaft, an output shaft and a speed change unit. Both ends of the input shaft are connected to bicycle pedals, the output shaft is connected to wheels, the input shaft and the output shaft are connected via a speed change unit, the speed change unit comprises a driving gear unit, a driven gear unit, a transmission gear unit and a speed change gear unit, the speed change gear unit comprises a speed change driving gear, a speed change driven gear, a number of driving speed change fork rods that is consistent with the number of driving gears and a number of driven speed change fork rods that is consistent with the number of driven gears, the speed change driving gear is provided with a driving jack, and the speed change driven gear is provided with a driven slot.

[0003] The above-mentioned gearbox has a complex structure, and is relatively heavy and bulky. Summary of the invention

[0004] In view of this, the present invention provides a speed change system and a bicycle, which are used to solve the problems of the prior art that the gearbox of the bicycle is complex in structure, heavy in weight and large in volume.

[0005] To achieve one or part or all of the above purposes or other purposes, the present invention provides a transmission system, comprising: a power shaft, a transmission shaft that is at least partially hollow, a first limiter, an output shaft that is at least partially hollow, a second limiter, a planetary gear set, a multi-stage driving wheel set, and a multi-stage driven wheel set;

[0006] The power shaft, transmission shaft and output shaft can be rotatably connected to the external housing, and the power shaft is transmission-connected to the transmission shaft;

[0007] The multi-stage driving wheel set can be rotatably arranged on the transmission shaft, and a first clutch transmission assembly is arranged between the transmission shaft and each stage of the multi-stage driving wheel set;

[0008] The sun gear and the multi-stage driven gear set of the planetary gear set can be rotatably arranged on the output shaft, and the multi-stage driven gear set is coaxially fixedly connected to form an amplifying gear set, the planetary gear of the planetary gear set is drivingly connected with the driven gear close to the planetary gear in the amplifying gear set, the inner gear ring is fixed on the external housing, and a second clutch transmission assembly is arranged between the output shaft and the amplifying gear set, and a third clutch transmission assembly is arranged between the output shaft and the sun gear;

[0009] The first limiter has a movable first limiter shaft extending into the interior of the transmission shaft, and the second limiter has a movable second limiter shaft extending into the interior of the output shaft; both the first limiter shaft and the second limiter shaft have a shifting convex portion;

[0010] The first limiter can drive the first limiter shaft to make its shift protrusion abut against any of the first clutch transmission components to achieve a transmission connection between the corresponding driving wheel and the output shaft; the second limiter can drive the second limiter shaft to make its shift protrusion abut against the second clutch transmission component to achieve a transmission connection between the output shaft and the amplifying wheel group, or drive the second limiter shaft to make its shift protrusion abut against the third clutch transmission component to achieve a transmission connection between the output shaft and the sun gear.

[0011] Furthermore, the first clutch transmission assembly, the second clutch transmission assembly and the third clutch transmission assembly are all composed of a pawl and a ratchet structure, the pawl is arranged on the transmission shaft and the output shaft, the ratchet structure is arranged on each stage of the multi-stage driving wheel group, the sun wheel and the amplifying wheel group, and the pawl is connected to a spring sheet, and the pawl is compressed by the spring sheet and is in a retracted state when not abutted by the shift convex portion, and the corresponding clutch transmission assembly is not connected; the pawl is in an extended state when abutted by the shift convex portion, and the corresponding clutch transmission assembly is transmission connected.

[0012] Furthermore, the first limiter further comprises: a slide cylinder;

[0013] One end of the slide cylinder is used to be inserted into and sealed and slidably connected to the oil cylinder on the external housing, and the other end of the slide cylinder extends into the output shaft to be connected to the second limit shaft;

[0014] The second limiter has the same structure as the first limiter.

[0015] Furthermore, the speed change system further comprises a driven sprocket key-connected to the transmission shaft, and a first limit ring is provided on one side of the driven sprocket; the transmission shaft is transmission-connected to the power shaft through the driven sprocket;

[0016] Each stage of the multi-stage driving wheel group is a structure with a first limiting ring on one side and a second limiting ring on the other side;

[0017] The driven sprocket and the adjacent first limiting ring and the second limiting ring in the multi-stage driving wheel group are movably sleeved.

[0018] Furthermore, the driven wheel of one stage of the multi-stage driven wheel set close to the planetary gear set is drivingly connected to the planetary gear of the planetary gear set and used as a planet carrier; the driven wheel is provided with a first connecting portion on the opposite side of the planetary gear, and the driven wheels of other stages of the multi-stage driven wheel set are sequentially sleeved and fixed on the first connecting portion;

[0019] A support bearing is provided between the first connecting portion and the output shaft;

[0020] The second clutch transmission assembly is arranged between the first connecting portion and the output shaft.

[0021] Further, the multi-stage driving wheel group includes: a first driving wheel, a second driving wheel and a third driving wheel; the multi-stage driven wheel group includes: a first driven wheel, a second driven wheel and a third driven wheel;

[0022] The first connecting portion is a structure having a stepped outer gear ring or a stepped connecting key connected to the axial direction of the first driven wheel; the second driven wheel and the third driven wheel are both fixedly connected to the first connecting portion;

[0023] The first driving wheel is meshed with the first driven wheel, the second driving wheel is meshed with the second driven wheel, and the third driving wheel is meshed with the third driven wheel.

[0024] Furthermore, the speed change system also includes a driving sprocket, which is arranged on the driving shaft and is drivingly connected to the driven sprocket through a chain.

[0025] Furthermore, the speed change system also includes a sprocket wheel, which is used to be fixed on the external housing and connected to the chain to reduce the transmission space of the chain.

[0026] Furthermore, the multi-stage driving wheel set is axially limited on the driven shaft by a retaining spring, and the multi-stage driven wheel set is axially limited on the output shaft by a retaining spring, and one end of the output shaft is also provided with a spline for connecting to a chainring.

[0027] To achieve one, part, or all of the above purposes or other purposes, the present invention further provides a bicycle, comprising the speed change system described in any one of the above.

[0028] Implementing the embodiments of the present invention will have the following beneficial effects:

[0029] After adopting the above-mentioned speed change system, since the speed change system only includes a planetary gear set, a multi-stage driving wheel set and a multi-stage driven wheel set between the transmission shaft and the output shaft; the transmission process is adjusted by the first limiting shaft arranged inside the transmission shaft and the second limiting shaft arranged inside the output shaft, the multi-stage driving wheel set and the multi-stage driven wheel set are directly transmitted, and no additional space is required to arrange the transmission gear set and the speed change gear set, thereby optimizing the transmission process, simplifying the gearbox structure of the bicycle, and making the weight and volume smaller. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0031] in:

[0032] Figure 1 An exploded view of the structure of a speed change system in one embodiment of the present invention;

[0033] Figure 2 A schematic diagram of the structure of a speed change system in one embodiment of the present invention;

[0034] Figure 3 for Figure 2 Another perspective of

[0035] Figure 4 It is a structural exploded diagram of a speed change system in another embodiment of the present invention;

[0036] Figure 5 It is a structural exploded diagram of a speed change system in another embodiment of the present invention;

[0037] Figure 6 A front view of a speed change system in one embodiment of the present invention;

[0038] Figure 7 for Figure 6 Schematic diagram of the middle AA section;

[0039] Figure 8 is a side view of a speed change system according to an embodiment of the present invention;

[0040] Fig. 9 for Figure 8 Schematic diagram of the middle BB section;

[0041] Fig.10 for Figure 8 Schematic diagram of the CC section.

[0042] Reference numerals:

[0043] 1. Shell; 101. Left shell; 1011. First oil cylinder; 1012. Second oil cylinder; 102. Right shell;

[0044] 2. Power shaft; 201. Power input end;

[0045] 3. Transmission shaft;

[0046] 4. first stopper; 401. first stopper shaft; 401a. shift convex portion; 402. slide cylinder;

[0047] 5. Output shaft; 501. Power output end;

[0048] 6. Second limiter; 601. Second limit axis;

[0049] 7. Planetary gear set; 701. Sun gear; 702. Internal gear ring; 703. Planetary gear;

[0050] 8. Multi-stage driving wheel set; 801. first driving wheel; 801a. second limiting ring; 802. second driving wheel; 803. third driving wheel;

[0051] 9. Multi-stage driven wheel set; 901. first driven wheel; 9011. first connecting portion; 902. second driven wheel; 903. third driven wheel;

[0052] 10. driven sprocket; 1001a. first limiting ring;

[0053] 11. Support bearing;

[0054] 12. Driving sprocket;

[0055] 13. Sprocket;

[0056] 14. Circlip. DETAILED DESCRIPTION

[0057] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by technicians in the technical field of the present invention; the terms used in the specification of the application herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention; the terms "including" and "having" and any variations thereof in the specification and claims of the present invention and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of the present invention or the above-mentioned drawings are used to distinguish different objects, not to describe a specific order.

[0058] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0059] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings.

[0060] Reference Figures 1 to 10 , in some embodiments, the present invention provides a speed change system, comprising: a power shaft, a transmission shaft that is at least partially hollow, a first limiter, an output shaft that is at least partially hollow, a second limiter, a planetary gear set, a multi-stage driving wheel set, and a multi-stage driven wheel set;

[0061] The power shaft, transmission shaft and output shaft can be rotatably connected to the external housing, and the power shaft is transmission-connected to the transmission shaft;

[0062] The multi-stage driving wheel set can be rotatably arranged on the transmission shaft, and a first clutch transmission assembly is arranged between the transmission shaft and each stage of the multi-stage driving wheel set;

[0063] The sun gear and the multi-stage driven gear set of the planetary gear set can be rotatably arranged on the output shaft, and the multi-stage driven gear set is coaxially fixedly connected to form an amplifying gear set, the planetary gear of the planetary gear set is drivingly connected with the driven gear close to the planetary gear in the amplifying gear set, the inner gear ring is fixed on the external housing, and a second clutch transmission assembly is arranged between the output shaft and the amplifying gear set, and a third clutch transmission assembly is arranged between the output shaft and the sun gear;

[0064] The first limiter has a movable first limiter shaft extending into the interior of the transmission shaft, and the second limiter has a movable second limiter shaft extending into the interior of the output shaft; both the first limiter shaft and the second limiter shaft have a shifting convex portion;

[0065] The first limiter can drive the first limiter shaft to make its shift protrusion abut against any of the first clutch transmission components to achieve a transmission connection between the corresponding driving wheel and the output shaft; the second limiter can drive the second limiter shaft to make its shift protrusion abut against the second clutch transmission component to achieve a transmission connection between the output shaft and the amplifying wheel group, or drive the second limiter shaft to make its shift protrusion abut against the third clutch transmission component to achieve a transmission connection between the output shaft and the sun gear.

[0066] In this embodiment, the power shaft has power input ends extending out of the housing at both ends, and the two power input ends are used to connect the crank and pedal of the bicycle. Specifically, splines may be provided at both ends, and the splines are used to connect the crank and pedal to provide input power; or the power shaft connects the crank and pedal in the same or similar manner as in the prior art. The output shaft has a power output end extending out of the housing at one end, and the power output end is used to connect the toothed disc of the bicycle, and the toothed disc is then transmitted to the wheel through a chain or the like.

[0067] The above-mentioned multi-stage driving wheel set and multi-stage driven wheel set can be a combination of multiple gears of different sizes or specifications. For example, the multi-stage driving wheel set is a combination of three gears of different sizes, and the multi-stage driven wheel set is a combination of three gears of different sizes, each gear corresponding to one stage, such as Figure 6 and Figure 7 As shown, of course, it can also be a combination of four, five or six gears, or even more, or a combination of two gears, as long as these gears are guaranteed to mesh with each level of the driving gear and each level of the driven gear after installation. More specifically, the sun gear of the planetary gear set is coaxially fixedly connected with the multi-stage driving gear set to form an amplifying gear set, which means that the sun gear and the multi-stage driving gear set are fixedly connected, and the formed amplifying gear set is a whole. When in use, the sun gear and the multi-stage driving gear set rotate together, that is, the angular velocity of each gear on the sun gear and the multi-stage driving gear set is consistent when rotating. The multi-stage driven gear set can be rotatably arranged on the output shaft, and relatively, each gear on the multi-stage driven gear set is independent of each other when rotating. The first clutch transmission assembly, the second clutch transmission assembly and the third clutch transmission assembly are all assemblies that can separate or engage the transmission, which can be a ratchet structure as described later, or other forms, for example, in the form of two friction plates, and the abutment or separation of the two friction plates is controlled by the shift convex portion to control the separation or engagement of the transmission. Figures 6 to 10 For example, when working, the first limiter drives the first limiter shaft to make its shift convex part abut against the first clutch transmission assembly required for output so that the corresponding driving wheel and the transmission shaft are connected in transmission, the second limiter drives the second limiter shaft to make its shift convex part abut against the second clutch transmission assembly so that the transmission shaft and the driven wheel are connected in transmission, or the second limiter drives the second limiter shaft to make its shift convex part abut against the third clutch transmission assembly so that the transmission shaft and the sun gear are connected in transmission. Take the shift convex part of the first limiter shaft abutting against the first clutch transmission assembly at the first gear position on the left in the multi-stage driving wheel group, and the shift convex part of the second limiter shaft abutting against the third clutch transmission assembly as an example, at this time, the power is transmitted from the power shaft to the multi-stage driving wheel group through the transmission shaft, and then transmitted from the driving wheel of the multi-stage driving wheel group above to the multi-stage driven wheel group, and then amplified by the planetary gear group and transmitted to the output shaft, and finally drives the toothed disc connected to the output shaft to output. Although the multi-stage driving wheel set and the multi-stage driven wheel set are all meshed in the above transmission process, since only the first gear on the left of the multi-stage driving wheel set has a transmission relationship with the transmission shaft, the other gears on the multi-stage driving wheel set are idle and do not affect the transmission process.

[0068] In summary, when both the multi-stage driving wheel set and the multi-stage driven wheel set are three-stage, the output shaft is connected to the amplifying wheel set or the sun gear, which can provide two different input speeds, and the transmission shaft is connected to the three-stage driving wheel set, each stage can obtain a different output speed, and the entire system can provide 2X3=6 different speed changes. Similarly, when both the multi-stage driving wheel set and the multi-stage driven wheel set are four-stage, 2X4=8 different speed changes can be provided. The same is true for other stages, which will not be repeated.

[0069] In some embodiments, the first clutch transmission assembly, the second clutch transmission assembly and the third clutch transmission assembly are all composed of a pawl and a ratchet structure. The pawl is arranged on the transmission shaft and the output shaft, and the ratchet structure is arranged on each level of the sun gear, the amplifying wheel set and the multi-stage driving wheel set, and the pawl is connected to a spring sheet. When the pawl is not abutted by the shift protrusion, it is compressed by the spring sheet and is in a retracted state, and the corresponding clutch transmission assembly is not connected; when the pawl is abutted by the shift protrusion, it is in an extended state, and the corresponding clutch transmission assembly is connected for transmission.

[0070] In this embodiment, if Fig. 9 and Fig.10 As shown, taking the first clutch transmission assembly on the transmission shaft as an example, a plurality of ratchet grooves are provided on the input shaft at the position corresponding to each gear on the multi-stage driving wheel set, and a plurality of ratchet grooves are correspondingly installed on the ratchet grooves, and one end of a spring sheet is connected to the ratchet, and the other end of the spring sheet is fixed to the transmission shaft. When the ratchet is not abutted by the shifting convex part, it is compressed by the spring sheet and is in a contracted state; when the ratchet is abutted by the shifting convex part, it is in an extended state; the inner ring of each gear on the multi-stage driving wheel set is provided with a ratchet structure, such as Fig. 9 As shown, the ratchet structures on other gears are similar to the above. The above first clutch transmission assembly is a combination of a pawl and a ratchet.

[0071] Reference Figure 4 , Figure 5 and Figure 7 , In some embodiments, the first stopper further comprises: a slide cylinder;

[0072] One end of the slide cylinder is used to be inserted into and sealed and slidably connected to the oil cylinder on the external housing, and the other end of the slide cylinder extends into the interior of the transmission shaft to be connected to the first limit shaft;

[0073] The second limiter has the same structure as the first limiter.

[0074] In this embodiment, the transmission shaft does not need to pass through the housing for installation, and the first limiter can be completely placed inside the output shaft. At this time, one end of the slide tube of the first limiter is inserted into and sealed to slide and connect the first oil cylinder on the housing, and the other end of the slide tube of the first limiter extends into the output shaft to connect the first limiter shaft, so that the movement of the slide tube can be controlled by the oil circuit to drive the movement of the first limiter shaft, thereby realizing precise control of the position of the shift convex part in the transmission shaft. In contrast, one end of the output shaft passes through the housing to output power to the toothed disc, and the second limiter can be placed inside the output shaft from the other end of the output shaft. At this time, one end of the slide tube of the second limiter is inserted into and sealed to slide and connect the second oil cylinder on the housing, and the other end of the slide tube of the second limiter extends into the output shaft to connect the second limiter shaft, so that the movement of the slide tube can be controlled by the oil circuit to drive the movement of the second limiter shaft, thereby realizing precise control of the position of the shift convex part in the output shaft.

[0075] Reference Figure 4 and Figure 5 In some embodiments, the speed change system further comprises a driven sprocket key-connected to the transmission shaft, and a first limit ring is provided on one side of the driven sprocket; the transmission shaft is connected to the power shaft through the driven sprocket;

[0076] Each stage of the multi-stage driving wheel set is a structure with a first limiting ring on one side and a second limiting ring on the other side;

[0077] The driven sprocket and the adjacent first limiting ring and the second limiting ring in the multi-stage driving wheel group are movably sleeved.

[0078] In this embodiment, a driven sprocket is provided on the transmission shaft, and the driven sprocket is connected to the driving sprocket on the power shaft to transmit power. It is worth mentioning that the driven sprocket and each gear of all the multi-stage driving wheel sets are movably connected with each other, that is, each stage of the multi-stage driving wheel set is provided with a first limiting ring on one side and a second limiting ring on the other side; the driven sprocket and the adjacent first limiting rings and second limiting rings in the multi-stage driving wheel set are movably connected. In this way, the driven sprocket can drive the transmission shaft to rotate, and each gear of the multi-stage driving wheel set can rotate independently of each other.

[0079] Reference Figures 2 to 5 In some embodiments, a driven wheel of a stage close to a planetary gear set in a multi-stage driven wheel set is drivingly connected to a planetary gear of the planetary gear set and is used as a planet carrier; the driven wheel is provided with a first connecting portion on the opposite side of the planetary gear, and the driven wheels of other stages in the multi-stage driven wheel set are sequentially sleeved and fixed on the first connecting portion;

[0080] A support bearing is provided between the first connecting portion and the output shaft;

[0081] The second clutch transmission assembly is arranged between the first connecting portion and the output shaft.

[0082] In this embodiment, the driven wheel of one stage of the multi-stage driven wheel set close to the planetary gear set is transmission-connected to the planetary wheel of the planetary gear set and used as a planetary carrier. This structural design eliminates the need for a separate planetary carrier, thus saving space and materials.

[0083] Reference Figures 2 to 5 In some embodiments, the multi-stage driving wheel set includes: a first driving wheel, a second driving wheel and a third driving wheel; the multi-stage driven wheel set includes: a first driven wheel, a second driven wheel and a third driven wheel;

[0084] The first connecting portion is a structure having a stepped outer gear ring or a stepped connecting key connected to the axial direction of the first driven wheel; the second driven wheel and the third driven wheel are both fixedly connected to the first connecting portion;

[0085] The first driving wheel is meshed with the first driven wheel, the second driving wheel is meshed with the second driven wheel, and the third driving wheel is meshed with the third driven wheel.

[0086] In this embodiment, the structure of the first driven wheel can be similar to a stepped triple gear, and the second driven wheel and the third driven wheel are sleeved on the step of the triple gear to form a whole. The overall angular velocity is consistent during movement. In addition, a support bearing is provided between the first driven wheel and the output shaft. Since the output shaft has a transmission relationship only with the sun gear or the amplifying wheel set when it moves, a support bearing is provided between the first driving wheel and the output shaft. The whole formed by the planetary gear set and the multi-stage driven wheel set has two support points, namely, the support bearing and the inner gear ring, which makes the rotation smoother and avoids the system from swinging.

[0087] Reference Figures 2 to 5 In some embodiments, the speed change system further includes a driving sprocket, which is disposed on the driving shaft and is drivingly connected to the driven sprocket via a chain.

[0088] Reference Figures 2 to 5 In some embodiments, the speed change system further includes a sprocket wheel, which is used to be fixed on the external housing and connected to the chain to reduce the transmission space of the chain.

[0089] In this embodiment, the sprocket can compress the width of the chain, as shown in FIG*, which can reduce the space occupied by some speed change systems, making the system more suitable for small or folding bicycles for easy storage and carrying.

[0090] Reference Figures 2 to 5 In some embodiments, the multi-stage driving wheel set is axially limited on the driven shaft by a retaining spring, and the multi-stage driven wheel set is axially limited on the output shaft by a retaining spring. A spline for connecting a toothed disc is also provided at one end of the output shaft.

[0091] Reference Figure 1In some embodiments, the housing is divided into two halves, namely, a left housing and a right housing. In order to increase the sealing performance, a sealing ring is provided at the joint of the left housing and the right housing to prevent water and dust. The power shaft, the transmission shaft and the output shaft are all connected to the housing through bearings. In addition, it should be noted that the first oil cylinder and the second oil cylinder on the housing can be integrally formed with the housing, or can be first made into independent oil cylinders and then assembled to the housing. The former has the advantage of better sealing performance, and can prevent sewage, silt, dust and other objects from entering the transmission system to pollute and even affect the use of the transmission structure during use, and can also achieve the effect of free cleaning and maintenance. The latter is simpler in process and easier to make. A sealing ring is added at the connection, which can also achieve the above-mentioned effect. In summary, after the bicycle is installed with the speed change system of the present invention, even if it is ridden on a muddy road, there is no fear that the system will be damaged due to the entry of foreign objects, which is particularly suitable for mountain bikes.

[0092] In some embodiments, the present invention further provides a bicycle, comprising any one of the above-mentioned speed change systems.

[0093] Obviously, the embodiments described above are only some embodiments of the present invention, rather than all embodiments. The preferred embodiments of the present invention are given in the accompanying drawings, but they do not limit the patent scope of the present invention. The present invention can be implemented in many different forms. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive. Although the present invention has been described in detail with reference to the aforementioned embodiments, for those skilled in the art, it is still possible to modify the technical solutions recorded in the aforementioned specific embodiments, or to perform equivalent replacements for some of the technical features therein. Any equivalent structure made using the contents of the specification and drawings of the present invention, directly or indirectly used in other related technical fields, is also within the scope of patent protection of the present invention.

Claims

1. A speed change system, characterized in that: include: A power shaft, a transmission shaft that is at least partially hollow, a first stopper, an output shaft that is at least partially hollow, a second stopper, a planetary gear set, a multi-stage driving wheel set, and a multi-stage driven wheel set; The power shaft, transmission shaft and output shaft can be rotatably connected to the external housing, and the power shaft is transmission-connected to the transmission shaft; The multi-stage driving wheel set can be rotatably arranged on the transmission shaft, and a first clutch transmission assembly is arranged between the transmission shaft and each stage of the multi-stage driving wheel set; The sun gear and the multi-stage driven gear set of the planetary gear set can be rotatably arranged on the output shaft, and the multi-stage driven gear set is coaxially fixedly connected to form an amplifying gear set, the planetary gear of the planetary gear set is drivingly connected with the driven gear close to the planetary gear in the amplifying gear set, the inner gear ring is fixed on the external housing, and a second clutch transmission assembly is arranged between the output shaft and the amplifying gear set, and a third clutch transmission assembly is arranged between the output shaft and the sun gear; The first limiter has a movable first limiter shaft extending into the interior of the transmission shaft, and the second limiter has a movable second limiter shaft extending into the interior of the output shaft; both the first limiter shaft and the second limiter shaft have a shifting convex portion; The first limiter can drive the first limiter shaft to make its shift protrusion abut against any of the first clutch transmission components to achieve a transmission connection between the corresponding driving wheel and the output shaft; the second limiter can drive the second limiter shaft to make its shift protrusion abut against the second clutch transmission component to achieve a transmission connection between the output shaft and the amplifying wheel group, or drive the second limiter shaft to make its shift protrusion abut against the third clutch transmission component to achieve a transmission connection between the output shaft and the sun gear.

2. The speed change system according to claim 1, characterized in that: The first clutch transmission assembly, the second clutch transmission assembly and the third clutch transmission assembly are all composed of a pawl and a ratchet structure. The pawl is arranged on the transmission shaft and the output shaft, and the ratchet structure is arranged on each stage of the multi-stage driving wheel set, the sun wheel and the amplifying wheel set, and the pawl is connected to a spring sheet. When the pawl is not abutted by the shift convex part, it is compressed by the spring sheet and is in a retracted state, and the corresponding clutch transmission assembly is not connected; when the pawl is abutted by the shift convex part, it is in an extended state, and the corresponding clutch transmission assembly is transmission connected.

3. The speed change system according to claim 1, characterized in that: The first stopper further comprises: a slide cylinder; One end of the slide cylinder is used to be inserted into and sealed and slidably connected to the oil cylinder on the external housing, and the other end of the slide cylinder extends into the output shaft to be connected to the second limit shaft; The second limiter has the same structure as the first limiter.

4. The speed change system according to claim 1, characterized in that: The speed change system also includes a driven sprocket key-connected to the transmission shaft, and a first limit ring is provided on one side of the driven sprocket; the transmission shaft is connected to the power shaft through the driven sprocket; Each stage of the multi-stage driving wheel group is a structure with a first limiting ring on one side and a second limiting ring on the other side; The driven sprocket and the adjacent first limiting ring and the second limiting ring in the multi-stage driving wheel group are movably sleeved.

5. The speed change system according to claim 1, characterized in that: A driven wheel of a stage close to the planetary gear set in the multi-stage driven wheel set is drivingly connected to the planetary gear of the planetary gear set and used as a planet carrier; the driven wheel is provided with a first connecting portion on the opposite side of the planetary gear, and the driven wheels of other stages in the multi-stage driven wheel set are sequentially sleeved and fixed on the first connecting portion; A support bearing is provided between the first connecting portion and the output shaft; The second clutch transmission assembly is arranged between the first connecting portion and the output shaft.

6. The speed change system according to claim 1, characterized in that: The multi-stage driving wheel group includes: a first driving wheel, a second driving wheel and a third driving wheel; the multi-stage driven wheel group includes: a first driven wheel, a second driven wheel and a third driven wheel; The first connecting portion is a structure having a stepped outer gear ring or a stepped connecting key connected to the axial direction of the first driven wheel; the second driven wheel and the third driven wheel are both fixedly connected to the first connecting portion; The first driving wheel is meshed with the first driven wheel, the second driving wheel is meshed with the second driven wheel, and the third driving wheel is meshed with the third driven wheel.

7. The speed change system according to claim 4, characterized in that: The speed change system further comprises a driving sprocket, which is arranged on the driving shaft and is drivingly connected to the driven sprocket through a chain.

8. The speed change system according to claim 7, characterized in that: The speed change system further comprises a sprocket wheel, which is used to be fixed on the external housing and connected with the chain to reduce the transmission space of the chain.

9. The speed change system according to claim 1, characterized in that: The multi-stage driving wheel set is axially limited on the driven shaft by a retaining spring, and the multi-stage driven wheel set is axially limited on the output shaft by a retaining spring. One end of the output shaft is also provided with a spline for connecting a toothed disc.

10. A bicycle, characterized in that: The bicycle comprises the speed change system according to any one of claims 1 to 9.

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