Gear shifting controller for load speed change of gearbox

Abstract

The utility model provides a gear shifting controller for load speed change of a gearbox. The gear shifting controller comprises a cam, a guide rod, a shifting fork mechanism and a ratchet wheel. A shifting fork mechanism is installed on the guide rod, a plurality of cam grooves are formed in the cam, the cam grooves are formed in the periphery of the cam in a surrounding mode, one end of the shifting fork mechanism slides along the cam grooves in the cam, and the other end of the shifting fork mechanism is connected with the ratchet wheel and drives the ratchet wheel to move. The pawl moving in the one-way mode is arranged on the ratchet wheel, on the basis that tooth breaking is prevented, gear shifting and gear shifting can be achieved under loads, and gear shifting can be conducted without stopping feet during pedaling riding.

Description

Technical Field

[0001] This utility model relates to the field of transmission structure, specifically to a shift controller for transmission load shifting. Background Technology

[0002] In the bicycle and e-bike industry, conventional external derailleurs can no longer meet market demands. Especially in the e-bike market, the addition of motors has led to a series of problems such as uneven shifting and chain breakage. Even industry benchmark products, such as the German Pinio derailleur, cannot achieve shifting under load.

[0003] In currently available solutions, there is a certain probability of gear grinding during gear shifting. Existing gearboxes, such as the one described in patent CN116816928B, use a spring-loaded shift fork to prevent gear grinding. However, under load, the spring-loaded shift fork cannot shift down; the load must be removed. This means the rider must stop pedaling before shifting down. This is inconvenient and prone to accidents. In electric-assisted bicycles, the gearbox incorporates a motor, which applies torque to the gears due to the motor's inertia, making downshifting even more impossible. Utility Model Content

[0004] In view of the deficiencies in the prior art, the purpose of this utility model is to provide a shift controller for gearbox load-based speed change.

[0005] According to the present invention, a gearbox load-changing shift controller includes: a cam, a guide rod, a shift fork mechanism, and a ratchet.

[0006] A shift fork mechanism is installed on the guide rod. The cam has multiple cam grooves, which are arranged around the periphery of the cam. One end of the shift fork mechanism slides along the cam groove on the cam, and the other end is connected to a ratchet and drives the ratchet to move.

[0007] Preferably, the ratchet includes: a pawl, a disc, a washer, a pawl mounting groove, and a spring;

[0008] The wheel is provided with a pawl mounting groove, and the pawl is slidably mounted in the pawl mounting groove along the axial direction.

[0009] A gasket is provided on one side of the pawl mounting groove. The gasket is fixedly mounted on the wheel. A spring is provided between the gasket and the pawl to push the pawl out of the wheel end face.

[0010] Preferably, the pawl is provided with a limiting boss on its side and a countersunk platform is provided in the pawl mounting groove. When the pawl is completely hidden in the pawl mounting groove against the spring force, it is limited by the interference between the limiting boss and the countersunk platform.

[0011] Preferably, the tooth surface of the pawl is composed of a tooth helical surface and a limiting surface.

[0012] Preferably, it further includes: a main shaft, a countershaft, a main shaft gear, and a countershaft gear;

[0013] One or more main shaft gears are mounted on the main shaft, one or more secondary shaft gears that mesh with the main shaft gears are mounted on the secondary shaft, and one or more ratchet wheels are mounted on the main shaft and / or the secondary shaft;

[0014] The guide rod drives the ratchet to move axially along the main shaft or the secondary shaft via a shift fork mechanism. The ratchet allows the pawl to mesh with the main shaft gear or the secondary shaft gear.

[0015] Preferably, the end faces of the main shaft gear and / or the counter shaft gear are provided with side teeth that mesh with the ratchet.

[0016] Preferably, the cam meshes with the gear shifting control gear set and rotates through the drive of the gear shifting control gear set.

[0017] Preferably, the cam groove is provided with a clearance groove for shifting gears.

[0018] Preferably, the shift fork mechanism is provided with a shift fork mounting hole for connecting the guide rod, and the shift fork mechanism is provided with a slider, which slides along the cam groove;

[0019] The ratchet has an annular groove in the middle of its circumference. The fork mechanism has two fork arms, and an annular contact surface that matches the shape of the annular groove is formed between the two fork arms. The two fork arms and the annular contact surface are engaged with the annular groove.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. This application achieves upshifting and downshifting under load by setting a unidirectional moving pawl on the ratchet, which prevents gear breakage and allows for gear shifting without stopping the pedal while riding.

[0022] 2. This application has a simple structure, which reduces costs and improves reliability. Attached Figure Description

[0023] Other features, objects, and advantages of this invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0024] Figure 1 This is a schematic diagram of the internal structure of the gearbox;

[0025] Figure 2 This is a front view of the internal structure of the gearbox;

[0026] Figure 3 A schematic diagram illustrating the structure for achieving ratchet movement;

[0027] Figure 4 This is a schematic diagram of the cam structure;

[0028] Figure 5 This is a schematic diagram of the shift fork mechanism;

[0029] Figure 6 This is a schematic diagram of a ratchet structure;

[0030] Figure 7 This is a schematic diagram of the pawl structure;

[0031] Figure 8 This is a schematic diagram of the roulette wheel structure;

[0032] Figure 9 This is a schematic diagram showing the position of the spring;

[0033] Figure 10 A schematic diagram showing the corresponding shapes of multiple cam grooves;

[0034] Figure 11 This is a schematic diagram of the pawl tilt angle;

[0035] As shown in the figure:

[0036] Detailed Implementation

[0037] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the present invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0038] like Figure 1-3As shown, this embodiment includes: a main shaft 1, a secondary shaft 2, a cam 3, a guide rod 4, a main shaft gear 5, a secondary shaft gear 6, a shift fork mechanism 7, and a ratchet 8. The main shaft 1, secondary shaft 2, cam 3, and guide rod 4 are installed inside the transmission housing. One or more main shaft gears 5 are installed on the main shaft 1, and one or more secondary shaft gears 6 meshing with the main shaft gears 5 are installed on the secondary shaft 2. One or more ratchet 8s are installed on the main shaft 1 and / or the secondary shaft 2. The shift fork mechanism 7 is installed on the guide rod 4. One end of the shift fork mechanism 7 slides along the cam groove on the cam 3, and the other end is connected to the ratchet 8, driving the ratchet 8 to move axially along the main shaft 1 or the secondary shaft 2. The cam 3 meshes with the shift control gear set 9 and rotates through the drive of the shift control gear set 9.

[0039] like Figure 6-9 As shown, the ratchet 8 also includes: a pawl 801, a wheel 802, a washer 803, a pawl mounting groove 806, and a spring 808; the end faces of the main shaft gear 5 and / or the counter-shaft gear 6 are provided with side teeth that mesh with the ratchet 8. The ratchet 8 is equipped with a pawl 801 that slides unidirectionally along the axial direction, allowing the ratchet 8 to mesh with the side teeth of the main shaft gear 5 or the counter-shaft gear 6 via the pawl 801. The wheel 802 is provided with a pawl mounting groove 806, and the pawl 801 is slidably mounted in the pawl mounting groove 806. A washer 803 is provided on one side of the pawl mounting groove 806, and the washer 803 is fixedly mounted on the wheel 802. A spring 808 is provided between the washer 803 and the pawl 801 to push the pawl 801 out of the end face of the wheel 802. When encountering gear grinding during upshifting, the pawl 801 can retract under the action of the spring 808. The side of the pawl 801 is provided with a limiting boss 805, and the pawl mounting groove 806 is provided with a recessed platform 807. When the pawl 801 overcomes the elastic force of the spring 808 and is completely hidden in the pawl mounting groove 806, it is limited by the interference between the limiting boss 805 and the recessed platform 807. When retracting, the recessed platform 807 will forcibly pull out the pawl 806, realizing retraction under load.

[0040] The cam 3 has multiple cam grooves arranged around its periphery. Each cam groove has a clearance groove 304 for shifting gears. One cam groove corresponds to one shift fork mechanism 7, and each shift fork mechanism 7 corresponds to at least one gear on each side. Figure 4As shown, there are 7 gears. The circumference of cam 3 is provided with a first cam groove 301, a second cam groove 302, and a third cam groove 303. The first cam groove 301 corresponds to gears 2 and 5, the second cam groove 302 corresponds to gears 4 and 7, and the third cam groove 303 corresponds to gears 3 and 6. Gear 1 uses a one-way clutch principle. When the cam groove corresponding to the shift fork mechanism 7 is in neutral (gear 1), the cam groove drives the shift fork mechanism 7 into gear 2, and gear 1 is in a slipping state. To shift from gear 2 to 3, the cam groove corresponding to gear 2 makes way for the gear 3 position (i.e., a clearance groove 304 is provided); to shift from gear 3 to 4, the cam groove corresponding to gear 3 makes way for the gear 4 position; to shift from gear 4 to 5, the cam groove corresponding to gear 4 makes way for the gear 5 position; to shift from gear 5 to 6, the cam groove corresponding to gear 5 makes way for the gear 6 position; and to shift from gear 6 to 7, the cam groove corresponding to gear 6 makes way for the gear 7 position.

[0041] like Figure 5 As shown, the shift fork mechanism 7 is provided with a shift fork mounting hole 701 for connecting the guide rod 4, and a slider 702 is provided on the shift fork mechanism 7, which slides along the cam groove; an annular groove is provided in the middle of the circumferential side of the ratchet 8, and two shift fork arms 703 are provided on the shift fork mechanism 7, forming an annular contact surface between the two shift fork arms 703 that matches the shape of the annular groove, and the two shift fork arms 703 and the annular contact surface are engaged at the annular groove. Compared with the traditional elastic shift fork, the shift fork mechanism 7 of this embodiment eliminates the elastic design. In another embodiment, the shift fork mechanism 7 and the guide rod 4 are integrated as a whole.

[0042] like Figure 11 As shown, the tooth surface of the pawl 801 is composed of a tooth helical surface 804 and a limiting surface. The angle between the tooth helical surface 804 and the end face of the wheel 802 is an obtuse angle, and the angle β between the limiting surface and the end face of the wheel 802 is approximately 92°, which facilitates better disengagement under load. The angle α between the peripheral side of the pawl 801 and the axial direction of the ratchet 8 is approximately 10°, thus ensuring that the pawl 801 will not slip under load and that the reverse push is smoother.

[0043] Upshifting process:

[0044] Taking the shift from 2nd to 3rd gear as an example, the rotation of cam 3 will drive the shift fork mechanism 7 to move, thereby driving ratchet 8 to move, so that ratchet 8 approaches the main shaft gear 5 or the secondary shaft gear 6 and produces teeth grinding. In the grinding state, pawl 801 will overcome the elastic force of spring 808 and retract. During the rotation, when the tooth surface of pawl 801 matches the side teeth of the main shaft gear 5 or the secondary shaft gear 6, pawl 801 will be pushed out under the elastic force of spring 808.

[0045] like Figure 10As shown, in the state where cam 3 pushes shift fork mechanism 7, in order to achieve seamless upshifting and uninterrupted power transmission, the cam groove is repositioned between 2nd and 3rd gear. This allows for upshifting to 3rd gear first, with power transmitted to the 3rd gear before disengaging from 2nd gear. For example... Figure 10 When the third cam groove 303 is in gear, the first cam groove 301 is provided with a clearance groove 304 to make way and solve the time difference.

[0046] When in 3rd gear, the ratchet 8 is under torque. The speed of 2nd gear is lower than that of 3rd gear. The wheel 802 in 2nd gear automatically disengages under the reverse push of the pawl 801 and the spring 808, completing the entire upshifting process.

[0047] Downshifting process:

[0048] During downshifting, the cam 3 rotates, which in turn pushes the shift fork mechanism 7 to move. The shift fork mechanism 7 drives the wheel 802 to move. The pawl 801 is provided with a limiting boss 805. The wheel 802 pulls the pawl 801 out through the countersunk platform 807 in conjunction with the limiting boss 805, thus achieving downshifting under light load.

[0049] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0050] The specific embodiments of this utility model have been described above. It should be understood that this utility model is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the substantive content of this utility model. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A shift controller for load-based gearbox speed change, characterized in that, include: Cam (3), guide rod (4), shift fork mechanism (7), and ratchet (8); The guide rod (4) is equipped with a shift fork mechanism (7). The cam (3) is provided with multiple cam grooves. The cam grooves are arranged around the periphery of the cam (3). One end of the shift fork mechanism (7) slides along the cam groove on the cam (3), and the other end is connected to a ratchet (8) and drives the ratchet (8) to move.

2. The shift controller for load-based gearbox speed change according to claim 1, characterized in that, The ratchet (8) includes: a pawl (801), a disc (802), a washer (803), a pawl mounting groove (806), and a spring (808); The wheel (802) is provided with a pawl mounting groove (806), and the pawl (801) is slidably mounted in the pawl mounting groove (806) along the axial direction; A gasket (803) is provided on one side of the pawl mounting groove (806). The gasket (803) is fixedly mounted on the wheel (802). A spring (808) is provided between the gasket (803) and the pawl (801) to push the pawl (801) out of the end face of the wheel (802).

3. The shift controller for load-based gearbox speed change according to claim 2, characterized in that: The pawl (801) has a limiting boss (805) on its side and a recessed platform (807) in the pawl mounting groove (806). When the pawl (801) overcomes the elastic force of the spring (808) and is completely hidden in the pawl mounting groove (806), it is limited by the interference between the limiting boss (805) and the recessed platform (807).

4. The shift controller for load-based gearbox speed change according to claim 2, characterized in that: The tooth surface of the pawl (801) is composed of a tooth helical surface (804) and a limiting surface.

5. The shift controller for load-based gearbox speed change according to claim 2, characterized in that, Also includes: Main shaft (1), secondary shaft (2), main shaft gear (5) and secondary shaft gear (6); One or more main shaft gears (5) are mounted on the main shaft (1), one or more secondary shaft gears (6) that mesh with the main shaft gears (5) are mounted on the secondary shaft (2), and one or more ratchet wheels (8) are mounted on the main shaft (1) and / or the secondary shaft (2); The guide rod (4) drives the ratchet (8) to move axially along the main shaft (1) or the secondary shaft (2) via the shift fork mechanism (7). The ratchet (8) allows the ratchet (8) to mesh with the main shaft gear (5) or the secondary shaft gear (6) via the pawl (801).

6. The shift controller for load-based gearbox speed change according to claim 5, characterized in that: The end faces of the main shaft gear (5) and / or the secondary shaft gear (6) are provided with side teeth that mesh with the ratchet (8).

7. The shift controller for load-based gearbox speed change according to claim 1, characterized in that: The cam (3) meshes with the gear shifting gear set (9) and rotates through the drive of the gear shifting gear set (9).

8. The shift controller for load-based gearbox speed change according to claim 1, characterized in that: The cam groove is provided with a clearance groove (304) for shifting gears.

9. The shift controller for load-based gearbox speed change according to claim 1, characterized in that: The shift fork mechanism (7) is provided with a shift fork mounting hole (701) for connecting the guide rod (4), and the shift fork mechanism (7) is provided with a slider (702), which slides along the cam groove; The ratchet (8) has an annular groove in the middle of its circumference. The shift fork mechanism (7) has two shift fork arms (703). An annular contact surface that matches the shape of the annular groove is formed between the two shift fork arms (703). The two shift fork arms (703) and the annular contact surface are engaged in the annular groove.

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