Multi-stage transmission device

Abstract

The multi-stage transmission device of the present application includes: a driving shaft that rotates by input of a rotational force; a plurality of driving gears that rotate by rotation of the driving shaft in combination with the driving shaft; a plurality of transmission gears that mesh with the driving gears; a transmission shaft that includes a plurality of pawl assemblies at least a portion of which protrudes from an outer circumferential surface, and that is combined with the transmission gears so as to selectively combine with at least a portion of the transmission gears as at least a portion of the pawl assemblies protrudes and retracts; a transmission control unit that selectively controls the protrusion and retraction of at least a portion of the pawl assemblies; a plurality of driven gears that mesh with at least a portion of the transmission gears; and a driven shaft that is combined with the plurality of driven gears for transmission of a rotational force to a driven body.

Description

Technical Field

[0001] The present invention relates to a multi-stage speed change device, and more specifically, all the speed change gears are coupled to a single shaft, thereby achieving excellent space efficiency by placing the driving shaft and the driven shaft on the same axis. Background Technology

[0002] The contents described in this section are for background information only and are not intended to constitute prior art.

[0003] Because the sprockets and chains in existing multi-stage transmissions are all exposed, problems arise such as reduced engagement strength between the sprockets and chains due to dust accumulation, and the chain easily detaching from the sprockets. Therefore, gearbox-type transmissions were developed that enclose the sprockets or gears in a housing to prevent them from being exposed. However, existing gearbox-type multi-stage transmissions require multiple shafts to engage the internal gears, resulting in increased manufacturing costs and time, and reduced space efficiency.

[0004] Therefore, the applicant proposed a multi-stage transmission device that reduces manufacturing costs and time by solving this problem and improves space efficiency by reducing space requirements. Therefore, a method for solving the problem described above is needed. Summary of the Invention

[0005] Technical issues

[0006] In the bicycle gearbox (Korean Patent No. 10-1223566), which is the prior art, all gears are included in one housing, which has the advantage of not being contaminated by dust. However, multiple gears need to be coupled to different shafts, which has the disadvantage of increasing volume and decreasing space efficiency.

[0007] Therefore, the object of the present invention is to provide a multi-stage speed change device that improves upon several shortcomings of the prior art mentioned above.

[0008] The purpose of this invention is not limited to the purposes mentioned above, and other purposes not mentioned can be clearly understood by those skilled in the art through the following description.

[0009] Technical solution

[0010] The multi-stage speed change device of the present invention for achieving the above-mentioned objectives includes: a drive shaft that rotates by inputting a rotational force; a plurality of drive gears that engage with the drive shaft and rotate by the rotation of the drive shaft; a plurality of transmission gears that mesh with the drive gears; a transmission shaft including a plurality of pawl assemblies, at least a portion of which moves in and out of the outer peripheral surface, that engages with the transmission gears and selectively engages with at least a portion of the transmission gears as at least a portion of the pawl assemblies moves in and out; a speed change control unit that selectively controls the movement of at least a portion of the pawl assemblies; a plurality of driven gears that mesh with at least a portion of the transmission gears; and a driven shaft that engages with the plurality of driven gears for transmitting rotational force to a driven body.

[0011] In this case, the driven shaft may include a hollow portion capable of accommodating at least a portion of the driving shaft, so as to engage with the outer peripheral surface of the driving shaft in a idling manner.

[0012] Furthermore, the aforementioned gear control unit may include: a plurality of guide members disposed in the hollow portion of the gear shaft and moving along the length of the gear shaft, thereby guiding a portion of the pawl assembly to move in and out by selectively contacting a portion of the pawl assembly; a plurality of guide rods, one side of which is connected to the plurality of guide members; a metal wire for gear shifting; and a gearshift disc capable of rotating via the metal wire, including a gearshift guide groove having a predetermined radius and length, the other side of which is in contact with the gearshift disc, and selectively inserted into the gearshift guide groove by rotating the gearshift disc, thereby causing the guide members to move selectively.

[0013] Furthermore, multiple guide components can be arranged side by side on a coaxial axis. Each guide component may include: a connecting hole for engaging with the guide rod; and one or more through holes arranged adjacent to the connecting hole, enabling the guide rod engaging with other guide components to pass through. The multiple connecting holes can be arranged in a staggered manner.

[0014] Furthermore, the aforementioned guide component may include a placement portion, which includes a placement inclined surface capable of placing a portion of the aforementioned pawl assembly.

[0015] In addition, a plurality of first insertion holes and second insertion holes arranged along the length direction of the gear shaft can be formed on the periphery of the gear shaft. The pawl assembly may include: a first pawl member, which is rotatably disposed in the first insertion hole and at least a portion of which is selectively exposed on the outside of the gear shaft; an elastic member inserted into the second insertion hole; and a second pawl member, which includes a first contact portion, a second contact portion, and a placement protrusion. The first contact portion contacts the first pawl member, the second contact portion contacts the elastic member, and the placement protrusion is formed protruding inward between the first contact portion and the second contact portion. It selectively contacts the placement inclined surface as the guide member moves. When the placement protrusion is placed on the placement inclined surface, an external force is applied to the first pawl member by the first contact portion, causing at least a portion of the first pawl member to be exposed on the outside, thereby locking into the locking groove formed on the inside of the gear.

[0016] The invention may further include a shaft cover, which is formed to surround the gearbox shaft and has a connecting hole that communicates with the first insertion hole.

[0017] Furthermore, the present invention may also include an introduction component disposed on the other side of the guide rod, which is selectively introduced into the gear shift guide groove.

[0018] Furthermore, the aforementioned introduction component may be ring-shaped, including a hollow portion, which may be combined with the other side of the aforementioned guide rod.

[0019] On the other hand, the aforementioned gear transmission may include: a first gear transmission section that meshes with the aforementioned driving gear; and a second gear transmission section that is coaxially arranged with the aforementioned first gear transmission section and meshes with the aforementioned driven gear, wherein the number of teeth of the plurality of gear transmissions in the aforementioned first gear transmission section and the second gear transmission section are different from each other.

[0020] In addition, the present invention may also include a ratchet between the plurality of drive gears to prevent the drive gears from reversing. A fixing protrusion is formed on the inner circumferential surface of the ratchet. The drive gear among the plurality of drive gears that is fixed with the ratchet causes the fixing part to protrude in the lateral direction. The fixing part is formed with a fixing groove along its periphery for inserting the fixing protrusion.

[0021] In this case, the aforementioned fixing groove may have a height difference portion formed on its inner side, and the first fixing groove of the first depth and the second fixing groove of the second depth formed at a position deeper than the first depth may be in a continuous connection.

[0022] The effects of the invention

[0023] The multi-stage speed change device of the present invention, which is used to achieve the above-mentioned objectives, integrates all the speed change gears onto a single shaft, and achieves excellent space efficiency by placing the driving shaft and the driven shaft on the same axis.

[0024] Furthermore, the multi-stage speed change device according to the present invention requires significantly fewer shafts, thereby greatly reducing manufacturing costs and time.

[0025] The effects of this invention are not limited to those mentioned above, and other effects not mentioned can be clearly understood by those skilled in the art through the description in the claims. Attached Figure Description

[0026] Figure 1 This is a perspective view of a multi-stage speed change device according to an embodiment of the present invention.

[0027] Figure 2 This is a perspective view of the gear section of a multi-stage speed change device according to an embodiment of the present invention.

[0028] Figure 3 This is a top view of the gear section of a multi-stage speed change device according to an embodiment of the present invention.

[0029] Figure 4 The diagram shows a perspective view (part (a)) of the speed control unit of a multi-stage speed change device according to an embodiment of the present invention, and detailed views (parts (b) and (c)) of the various structures of the speed control unit.

[0030] Figure 5 The images show a side view and a top view of the gearbox of a multi-stage speed change device according to an embodiment of the present invention.

[0031] Figure 6 The diagram illustrates the guide rod, the inlet component, and the gear shift disc of a multi-stage speed change device according to an embodiment of the present invention.

[0032] Figure 7 This diagram illustrates the combined structure of the speed-changing shaft and related structures in a multi-stage speed-changing device according to an embodiment of the present invention.

[0033] Figure 8 and Figure 9 This diagram illustrates the driving principle of the pawl assembly in a multi-stage speed change device according to an embodiment of the present invention.

[0034] Figure 10 This diagram illustrates the combination structure of the drive gear and ratchet in a multi-stage speed change device according to an embodiment of the present invention. Detailed Implementation

[0035] Hereinafter, preferred embodiments of the present invention, which specifically achieve the objectives of the present invention, will be described with reference to the accompanying drawings. In the description of these embodiments, the same names and reference numerals will be used for the same structures, and additional descriptions thereof will be omitted.

[0036] Figure 1 This is a perspective view of a multi-stage speed change device according to an embodiment of the present invention.

[0037] and, Figure 2 This is a perspective view of the gear section of a multi-stage speed change device according to an embodiment of the present invention. Figure 3 This is a top view of the gear section of a multi-stage speed change device according to an embodiment of the present invention.

[0038] Reference Figures 1 to 3 A multi-stage transmission device 100 according to an embodiment of the present invention may include a drive shaft 10, a housing 200, and an input pedal connected to the drive shaft 10. The housing 200 is used to house the gear section included inside (described later), and may include a first cover 210, a second cover 220, a main body cover 230, and a transmission disc cover 240.

[0039] Furthermore, it may include a metal wire 250 for rotating the gearshift disc described later.

[0040] Furthermore, referring to Figure 2 and Figure 3 A multi-stage speed change device according to an embodiment of the present invention may include a gear section 310 to 340 integrating multiple gears.

[0041] The gear units 310 to 340 may include a driving gear 310, a transmission gear 320, 330, and a driven gear 340. Furthermore, they may also include a driving shaft 10, a transmission shaft 20, a driven shaft 30, and a transmission control unit for controlling the speed change.

[0042] The drive shaft 10 rotates in response to an input rotational force and may include multiple drive gears 310, which can rotate in conjunction with the drive shaft 10 as the drive shaft 10 rotates. That is, the drive gears 310 do not idle relative to the drive shaft 10. The drive gears 310 can transmit the input rotational force to the transmission gears 320 and 330. As shown in the figure, the multiple drive gears 310 can be configured with different numbers of teeth.

[0043] The transmission gears 320 and 330 may include a first transmission gear section 320 and a second transmission gear section 330.

[0044] The first gear section 320 meshes with the driving gear 310, and the number of teeth between them may be different. The second gear section 330 is arranged on the same shaft as the first gear section 320 and meshes with the driven gear 340, and may have different numbers of teeth.

[0045] The first gear section 320 and the second gear section 330 can idle relative to the gear shaft 20 or selectively mesh with the gear shaft 20. To achieve the desired gear ratio, only the required gears from the plurality of gears 320, 330 can mesh with the gear shaft 20. For this purpose, at least one of the first gear sections 320 meshing with the driving gear 310 and at least one of the second gear sections 330 meshing with the driven gear 340 are engaged with the gear shaft 20. Overall, at least two gears from the gear sections 320, 330 mesh with the gear shaft 20.

[0046] However, here, the leftmost gear with the largest diameter in the first gear section 320 (as shown in the attached figure) and the rightmost gear with the smallest diameter in the second gear section 330 can always be engaged with the gearshift shaft 20. The leftmost gear with the largest diameter in the first gear section 320 and the rightmost gear with the smallest diameter in the second gear section 330 correspond to the lowest gear ratio, which allows for the lowest speed. That is, the lowest gear ratio is set to a base value so that the vehicle can operate at the lowest gear ratio even without shifting gears.

[0047] That is, only the gear with the largest diameter located on the far left of the first gear section 320 and the gear with the smallest diameter located on the far right of the second gear section 330 are set to the lowest gear when engaged with the gear shaft 20. At the same time, the gear can be changed when other gears of the first gear section 320 or other gears of the second gear section 330 are additionally engaged with the gear shaft 20.

[0048] The shift shaft 20 may selectively engage with at least a portion of the shift gears 320 and 330. For this purpose, the shift shaft 20 may include a plurality of pawl assemblies 600 (see reference 'pawl') extending and retracting from the outer peripheral surface. Figures 7 to 9 This may include multiple insertion holes for engaging with the pawl assembly 600. The pawl assembly 600 and the insertion holes will be described in detail later.

[0049] The gearshift shaft 20 has a hollow space within which multiple guide members 400 can be arranged. These guide members 400 move along the length of the gearshift shaft 20, thereby guiding the structural elements included in the ratchet assemblies 600 into and out of the ratchet assemblies 600 by selectively contacting them. Details will be explained later, but for gear shifting control, the gear shift gears 320 and 330 can selectively engage with the gearshift shaft 20 by selectively moving the guide members 400 back and forth.

[0050] Driven gear 340 may mesh with at least a portion of transmission gears 320 and 330, preferably with the second transmission gear 330.

[0051] Driven shaft 30 can engage with driven gear 340 in a non-free-rotating manner. Driven shaft 30 may include a hollow portion capable of accommodating at least a portion of drive shaft 10, and can engage with the outer peripheral surface of drive shaft 10 in a free-rotating manner. Driven shaft 30 can transmit rotational force to the driven body via a chain by externally mounting a separate sprocket.

[0052] As described above, by arranging the driven shaft 30 and the driving shaft 10 on the same axis, rather than as separate shafts, the space efficiency can be maximized by combining with the outer peripheral surface of the driving shaft 10 in a manner that allows for free rotation.

[0053] Figure 4 The diagram shows a perspective view (part (a)) of the speed control unit of a multi-stage speed change device according to an embodiment of the present invention, and detailed views (parts (b) and (c)) of the various structures of the speed control unit.

[0054] Figure 5 The images show a side view and a top view of the gearbox of a multi-stage speed change device according to an embodiment of the present invention.

[0055] Figure 6 The diagram illustrates the guide rod, the inlet component, and the gear shift disc of a multi-stage speed change device according to an embodiment of the present invention.

[0056] Figure 7 This diagram illustrates the combined structure of the speed-changing shaft and related structures in a multi-stage speed-changing device according to an embodiment of the present invention.

[0057] Reference Figures 4 to 7 The speed control unit can control the speed change by selectively engaging the speed change shaft 20 with the speed change gears 320 and 330.

[0058] The transmission control unit may include a metal wire, a transmission disc 500, a guide member 400, and a ratchet assembly 600. Furthermore, it may include a guide rod 410 and an introduction member 430 for connecting the guide member 400 and the transmission disc 500.

[0059] First, the general operating principle of the transmission control unit is as follows: the transmission disc 500 rotates with the operation of the metal wire. The rotation of the transmission disc 500 causes the guide rod 410 to move back and forth along the direction of the transmission shaft 20. This causes the guide component 400 to move back and forth. As the guide component 400 moves back and forth, at least a portion of the multiple ratchet assemblies 600 of the transmission shaft 20 selectively contact the guide component 400. This causes the configuration angle of the ratchet assembly 600 to change. As the configuration angle of the ratchet assembly 600 changes, at least a portion of the transmission gears 310 to 340 arranged on the same straight line as the corresponding ratchet assembly 600 mesh with the transmission shaft 20, thereby controlling the desired gear ratio.

[0060] In this configuration, the three gears 401, 402, and 403 on the left side of the guide component 400 in the attached figure interact with the three gears on the right side of the first transmission gear unit 320, and the two gears on the right side of the attached figure interact with the two gears 404 and 405 on the left side of the second transmission gear unit 330, and are configured and constructed as described above.

[0061] First, refer to Figure 5 The gearbox 500 can be rotated by a metal wire and may include gear guide grooves 510 and 530 with a specified radius and length on its inner side.

[0062] The gear shift guide grooves 510 and 530 may include a first gear shift guide groove 510 and a second gear shift guide groove 530.

[0063] The first speed change guide groove 510 is located on the outermost concentric circle and can be divided into 3 grooves.

[0064] The second speed guide groove 530 is located on a concentric circle on the inner side and can be composed of one groove.

[0065] As shown in the figure, the first speed guide groove 510 makes the angle between the centers of the three grooves 120° apart from each other with the center of the circle as the reference.

[0066] The second gear guide slot 530 can be configured such that a consecutive slot is arranged adjacent to the first gear guide slot 510.

[0067] The details will be explained later, but as the gearbox 500, which includes the gear guide grooves 510 and 530 formed as described above, rotates, the guide rod 410 or the insertion member 430 is selectively inserted into the gear guide grooves 510 and 530, thereby allowing the guide member 400 to move back and forth along the direction of the gear shaft 20.

[0068] Next, refer to Figure 4This allows one to understand the structure of the guide component 400, guide rod 410, introduction component 430, and guide shaft 450.

[0069] Reference Figure 4 In part (b), the guide component 400 may be composed of multiple components 401, 402, 403, 404, and 405. However, although it is composed of 5 components in the drawings, the invention is not limited to this, and the number may be changed as needed, with a minimum of 2 or more.

[0070] The guide component 400 (401, 402, 403, 404, 405) may each include a connecting hole 410a (411a, 412a, 413a, 414a, 415a) and one or more through holes 410b (411b, 412b, 413b, 414b, 415b).

[0071] A hollow space can be formed at the center of each guide component 400, through which the guide shaft 450 passes.

[0072] The engagement hole 410a can be engaged with the guide rod 410. As described above, the guide rod 410 can guide the guide member 400 to move back and forth along the axial direction according to the rotation of the gearbox 500.

[0073] The through hole 410b can be configured such that the guide rod 410, which is combined with other guide components 400, passes through it.

[0074] like Figure 4 As shown in section (c), with the guide member 400 configured as described above, such that a plurality of guide members 401, 402, 403, 404, 405 are arranged side by side on the coaxial axis, they can selectively slide on the guide shaft 450 and move back and forth along the direction of the guide shaft 450 as the gearbox 500 rotates.

[0075] The guide rods 411, 412, 413, 414, and 415 can each have different lengths. One side of each guide rod 411, 412, 413, 414, and 415 can be connected to guide components 401, 402, 403, 404, and 405, respectively, while the other side can contact the gearshift disc 500. The other side of each guide rod 411, 412, 413, 414, and 415 can be bent once perpendicular to its length direction, and an introduction component 430 can be provided in the bent portion.

[0076] The introduction component 430 may be ring-shaped with a hollow portion, which may be combined with the curved portion on the other side of the guide rods 411, 412, 413, 414, 415. The introduction component 430 may be selectively introduced / inserted into the transmission guide slots 510, 530 as the transmission disc 500 rotates.

[0077] Reference Figure 6 It is possible to monitor the status of the guide rod 410 and the introduction component 430 configured on one side of the first cover 210.

[0078] The gearshift joint 260 may be formed on the outer side of the first cover 210. The gearshift joint 260 may be shaped such that the gearshift 500 is joined and placed with the gearshift joint 260.

[0079] A guide member 270 may be formed at the center of the gearbox engagement portion 260, and a plurality of guide grooves 271 may be formed in the guide member 270 for placing at least a portion of the guide rod 410 and for moving back and forth. An elastic member 272 may be provided at the lower end of the guide groove 271, and the elastic member 272 is used to apply force to each guide rod 410 in an outward direction, that is, to apply force toward the gearbox 500.

[0080] The gearbox engagement portion 260 may include a plurality of extended guide grooves, which extend from each guide groove 271 of the guide member 270 and are formed to the edge of the gearbox engagement portion 260. The extended guide grooves are formed in such a way as to accommodate the entire guide rod 410 and the introduction member 430, and are formed to a predetermined depth in such a way as not to hinder the forward and backward movement of the guide rod 410 and the introduction member 430.

[0081] Re-reference Figure 6 The state of each inlet component 430 placed in the gear shift guide slots 510 and 530 of the gear shift disk 500 can be monitored. In the attached figure, the inlet components 430 do not rotate, but the gear shift disk 500 rotates, thereby causing at least a portion of the inlet components 430 to be selectively inserted into or not inserted into the gear shift guide slots 510 and 530. Through this operation, at least a portion of the guide components 400 can be selectively moved back and forth.

[0082] Figure 7 This diagram illustrates the combined structure of the gearbox 20 and related structures in a multi-stage gearbox according to an embodiment of the present invention. Figure 8 and Figure 9 The diagram illustrates the driving principle of the pawl assembly 600 in a multi-stage speed change device according to an embodiment of the present invention.

[0083] like Figures 7 to 9As shown, in this embodiment, a plurality of first insertion holes 21 and second insertion holes 22 arranged along the length direction of the gear shaft 20 can be formed on the surrounding surface of the gear shaft 20.

[0084] In this case, the pawl assembly 600 includes: a first pawl member 610 rotatably disposed in the first insertion hole 21, at least a portion of which is selectively exposed to the outside of the gear shift shaft 20; an elastic member 630 inserted into the second insertion hole 22; and a second pawl member 620.

[0085] Specifically, the first pawl component 610 includes: a shaft providing portion 612 for providing a rotating shaft; and a locking portion 611 that selectively exposes to the outside of the transmission shaft 20 when the first pawl component 610 rotates about the shaft providing portion 612.

[0086] Furthermore, the second pawl component 620 includes: a first contact portion 621 that contacts the first pawl component 610; a second contact portion 622 that contacts the elastic component 630; and a placement protrusion 623 that protrudes inward between the first contact portion 621 and the second contact portion 622 and selectively contacts the placement inclined surface 406 as the guide component 400 moves.

[0087] Therefore, as Figure 9 As shown, when the guide member 400 moves to place the placement protrusion 623 on the placement inclined surface 406, as the first contact part 621 applies external force to the first pawl member 610, the locking part 611 of the first pawl member 610 is exposed on the outside, thereby locking into the locking groove 321 formed on the inner side of the transmission gears 320 and 330, thereby realizing power transmission.

[0088] That is, although mentioned earlier, the lowest gear is set to its base value with it always engaged. In this state, if some of the other gears selected by the ratchet assembly 600 engage with the shift shaft 20, a gear shift will occur according to the gear ratio corresponding to the selected gear. In other words, the lowest gear is equivalent to a gear ratio exhibiting the lowest speed. If higher gears exhibiting speeds above this are engaged and rotating, the low speed can be ignored, and therefore, it will not have any effect on the gear shift.

[0089] On the other hand, such as Figure 7 As shown, in this embodiment, a shaft cover 40 may also be included, formed to surround the gear shift shaft 20, and having a connecting hole 41 communicating with the first insertion hole 21. The shaft cover 40 can be used to strengthen the gear shift shaft 20 and assist the driving of the ratchet assembly 600.

[0090] In addition, in this embodiment, a first gear fixing groove 23 may be formed on one side of the gear shaft 20, and a second gear fixing groove 42 connected to the first gear fixing groove 23 may be formed on one side of the shaft cover 40.

[0091] This is to achieve the following purpose: by combining with the protrusion formed on the inner circumferential surface of the largest diameter gear located on the leftmost side of the first gear section 320, the largest diameter gear located on the leftmost side of the first gear section 320 can be substantially fixed to the gear shaft 20.

[0092] Figure 10 This diagram illustrates the connection structure of the drive gear 310 and ratchet 350 in a multi-stage speed change device according to an embodiment of the present invention.

[0093] like Figure 10 As shown, in this embodiment, the present invention may further include a ratchet 350 between the plurality of drive gears 310 to prevent the drive gears 310 from reversing, and a fixing protrusion 351 is formed on the inner circumferential surface of the ratchet 350. Moreover, a restoring elastic member 312 may be provided between the ratchet 350 and one drive gear 310 to provide a restoring force between the ratchet 350 and the drive gear 310.

[0094] In this case, the drive gear 310 with the ratchet 350 fixed in one of the multiple drive gears 310 causes the fixing part 311 to protrude in the lateral direction, and the fixing part 311 has a fixing groove 312 for inserting the fixing protrusion 351 around its periphery.

[0095] Furthermore, the fixing groove 312 has a height difference portion formed on its inner side, and the first fixing groove 312a of the first depth and the second fixing groove 312b of the second depth formed at a position deeper than the first depth can be continuously connected. This is to improve the bonding force by having the fixing protrusion 351 inserted into the fixing groove 312 in stages according to the bonding depth.

[0096] Having understood the preferred embodiments of the present invention above, it is self-evident to those skilled in the art that, in addition to the embodiments described above, the present invention can be implemented in other specific ways without departing from its spirit or scope. Therefore, the above embodiments should be regarded as exemplary embodiments, not limiting embodiments. Thus, the present invention can be modified within the scope of the appended claims and its equivalents, without being limited to the above description.

Claims

1. A multi-stage speed change device, characterized in that, include: The drive shaft rotates by inputting rotational force. Multiple drive gears are combined with the aforementioned drive shaft, and rotation is achieved through the rotation of the aforementioned drive shaft; Multiple speed-changing gears mesh with the aforementioned driving gear; The gear shaft includes a plurality of pawl assemblies, at least a portion of which move in and out of the outer peripheral surface, and engages with the gears described above. As at least a portion of the pawl assemblies moves in and out, they selectively engage with at least a portion of the gears described above. The speed control unit selectively controls the entry and exit of at least a portion of the aforementioned ratchet assembly; A plurality of driven gears mesh with at least a portion of the aforementioned transmission gears; and The driven shaft, in conjunction with the aforementioned driven gears, is used to transmit rotational force to the driven body. The aforementioned speed control unit includes: A guide component, a plurality of guide components are disposed in the hollow portion of the aforementioned gear shaft, and move along the length direction of the aforementioned gear shaft, thereby guiding a portion of the aforementioned pawl assembly to move in and out by selectively contacting a portion of the aforementioned pawl assembly. Multiple guide rods, each connected on one side to one of the aforementioned guide components; Metal wire, used for speed changing; and The gearshift disc, capable of rotating via the aforementioned metal wire, includes gearshift guide grooves with a specified radius and length. The other side of each of the aforementioned guide rods contacts the aforementioned gear shift disc, and is selectively inserted into the aforementioned gear shift guide groove by rotating the aforementioned gear shift disc, thereby allowing the aforementioned guide components to move selectively. The aforementioned guide component includes a placement portion, which includes a placement inclined surface capable of placing a portion of the aforementioned pawl assembly. A plurality of first insertion holes and second insertion holes are formed on the periphery of the aforementioned gear shaft, arranged along the length direction of the aforementioned gear shaft. The aforementioned pawl assembly includes: The first pawl component is rotatably disposed in the first insertion hole, allowing at least a portion to be selectively exposed on the outside of the gearbox shaft. The elastic member is inserted into the second insertion hole; and The second pawl component includes a first contact portion, a second contact portion, and a placement protrusion. The first contact portion contacts the first pawl component, the second contact portion contacts the elastic component, and the placement protrusion is formed protruding inward between the first and second contact portions, selectively contacting the inclined placement surface as the guide component moves. When the aforementioned placement protrusion is placed on the aforementioned placement inclined surface, as the aforementioned first contact portion applies external force to the aforementioned first pawl member, at least a portion of the aforementioned first pawl member is exposed on the outside, thereby locking into the locking groove formed on the inside of the aforementioned gear.

2. The multi-stage speed change device according to claim 1, characterized in that, The driven shaft includes a hollow portion capable of accommodating at least a portion of the driving shaft, and engages with the outer peripheral surface of the driving shaft in a idling manner.

3. The multi-stage speed change device according to claim 1, characterized in that, Multiple of the aforementioned guide components are arranged side by side on a coaxial axis. Each guide component includes: A connecting hole for engaging with the aforementioned guide rod; and One or more through holes, arranged adjacent to the aforementioned connecting holes, allow the guide rod, which is to be combined with other guide components, to pass through. The aforementioned connecting holes are arranged in a staggered manner.

4. The multi-stage speed change device according to claim 1, characterized in that, It also includes a shaft cover, which is formed to surround the aforementioned gearbox shaft and has a connecting hole that communicates with the aforementioned first insertion hole.

5. The multi-stage speed change device according to claim 1, characterized in that, It also includes an inlet component, which is disposed on the other side of the guide rod and is selectively introduced into the gear shift guide groove.

6. The multi-stage speed change device according to claim 5, characterized in that, The aforementioned introductory component is ring-shaped, including a hollow portion, which is combined with the other side of the aforementioned guide rod.

7. The multi-stage speed change device according to claim 1, characterized in that, The aforementioned transmission gears include: The first transmission gear section meshes with the aforementioned drive gear; and The second transmission gear unit is arranged coaxially with the first transmission gear unit and meshes with the driven gear. The number of teeth on the multiple gears in the first and second gear sections are different from each other.

8. The multi-stage speed change device according to claim 1, characterized in that, A ratchet is also included between the aforementioned multiple drive gears to prevent the drive gears from reversing. A fixing protrusion is formed on the inner circumferential surface of the ratchet. The ratchet is fixed to one of the aforementioned multiple drive gears, causing the fixing part to protrude in the lateral direction. The fixing part has a fixing groove formed around its periphery for inserting the fixing protrusion.

9. The multi-stage speed change device according to claim 8, characterized in that, The aforementioned fixing groove has a height difference portion formed on its inner side, and the first fixing groove of the first depth and the second fixing groove of the second depth formed at a position deeper than the first depth are continuously connected.

Images