Seven-gear speed change mechanism of motorcycle

Abstract

The seven-gear speed change mechanism comprises a driving shaft, a driven shaft and a shifting fork set, a third driving gear and a fifth driving gear are both connected with a spline of the driving shaft, the third driving gear is matched with a second driving gear and a fourth driving gear in a clutch mode, and the fifth driving gear is matched with a sixth driving gear in a clutch mode. The second driven gear is in clutch fit with the first driven gear and the third driven gear, and the sixth driven gear is in clutch fit with the fifth driven gear and the seventh driven gear. The shifting fork set comprises a first shifting fork used for driving the third driving gear to move, a second shifting fork used for driving the fifth driving gear to move, a third shifting fork used for driving the second driven gear to move and a fourth shifting fork used for driving the sixth driven gear to move. According to the scheme, the problem that installation and use are affected due to the fact that a speed change mechanism is large in size in the prior art is solved.

Description

Technical Field

[0001] This utility model relates to a motorcycle transmission device, specifically a seven-speed motorcycle transmission mechanism. Background Technology

[0002] A motorcycle transmission mechanism is a set of gears with multiple positions between the drive shaft and the driven shaft to achieve different gear shifting requirements. Most existing motorcycle transmission mechanisms are six-speed. However, in practical use, it has been found that these mechanisms, when used on automatic transmission motorcycles, can easily cause shifting jerks, thus affecting the driving experience.

[0003] Chinese patent document CN215293467U discloses a seven-speed transmission mechanism, including a drive shaft, a driven shaft, a shift fork shaft, and a shift shaft. The drive shaft has a first drive gear, a sixth drive gear, a fourth drive gear, a fifth drive gear, a seventh drive gear, a third drive gear, and a second drive gear arranged sequentially along its axial direction. The driven shaft has a first driven gear, a sixth driven gear, a fourth driven gear, a fifth driven gear, a seventh driven gear, a third driven gear, and a second driven gear arranged sequentially along its axial direction. The first, second, third, fourth, and fifth drive gears rotate with the drive shaft. The sixth and seventh drive gears are axially fixed to the drive shaft and rotate relative to it. The first, second, third, fourth, and fifth driven gears are axially fixed to the driven shaft and rotate relative to it. The sixth driven gear... The first driven gear and the seventh driven gear drive the driven shaft to rotate and are slidably connected to the driven shaft. The fourth and fifth driving gears are fixed to each other and slidably connected to the driving shaft. The opposite sides of the fourth and fifth driving gears are respectively provided with transmission teeth that can drive the sixth and seventh driving gears. The sixth driven gear is provided with transmission teeth on both sides that can be connected to the first and fourth driven gears. The seventh driven gear is provided with transmission teeth on both sides that can be connected to the fifth and third driven gears. The second driven gear is also provided with a shift ring slidably connected to the driven shaft and capable of driving the driven shaft to rotate. The shift ring is provided with transmission teeth on one side that can be connected to the second driven gear. Four shift forks are slidably connected to the shift fork shaft, which respectively drive the fourth driving gear, the sixth driven gear, the seventh driven gear, and the shift ring to move axially. The shift shaft selectively drives one of the four shift forks to move to their respective sides and reset. The beneficial effects of this prior art are: by cooperating with seven different gear sets, a seven-speed transmission is achieved, providing more gears, smoother shifting, and a better driving experience.

[0004] While the aforementioned existing technologies make shifting smoother and reduce shift shock, thereby improving the driving experience, the transmission mechanism has three shift forks on the driven shaft and one shift fork on the drive shaft. This results in a relatively large clearance between the gears on the drive shaft and the driven shaft, which in turn makes the axial dimension of the entire transmission mechanism relatively large. This requires more installation space and is not conducive to installation and use on motorcycles. Utility Model Content

[0005] The purpose of this utility model is to provide a seven-speed transmission mechanism for motorcycles, so as to solve the problem that the large size of the transmission mechanism in the prior art affects the installation and use.

[0006] To achieve the above objectives, the basic solution of this utility model provides a seven-speed transmission mechanism for motorcycles, including a drive shaft, a driven shaft, and a shift fork assembly. The drive shaft has a first drive gear, a second drive gear, a third drive gear, a fourth drive gear, a fifth drive gear, a sixth drive gear, and a seventh drive gear arranged sequentially along the axial direction. The driven shaft has a first driven gear, a second driven gear, a third driven gear, a fourth driven gear, a fifth driven gear, a sixth driven gear, and a seventh driven gear arranged sequentially along the axial direction.

[0007] The first and seventh drive gears are both statically connected to the drive shaft, the second, fourth, and sixth drive gears are all rotatably connected to the drive shaft, the third and fifth drive gears are both splined connected to the drive shaft, the third drive gear engages with the second and fourth drive gears respectively, and the fifth drive gear engages with the sixth drive gear.

[0008] The first driven gear, the third driven gear, the fifth driven gear, and the seventh driven gear are all rotatably connected to the driven shaft, the fourth driven gear is statically connected to the driven shaft, the second driven gear and the sixth driven gear are both splined connected to the driven shaft, the second driven gear engages with the first driven gear and the third driven gear respectively, and the sixth driven gear engages with the fifth driven gear and the seventh driven gear respectively.

[0009] The shift fork assembly includes a first shift fork for driving the third driving gear, a second shift fork for driving the fifth driving gear, a third shift fork for driving the second driven gear, and a fourth shift fork for driving the sixth driven gear.

[0010] The beneficial effects of this basic scheme are as follows: by controlling the movement of the third drive gear through the first shift fork, the movement of the fifth drive gear through the second shift fork, the movement of the second driven gear through the third shift fork, and the movement of the sixth driven gear through the fourth shift fork, it is possible to achieve the switching operation of seven gears. Furthermore, the drive shaft and the driven shaft each cooperate with two shift forks individually, thereby making the gear arrangement on the drive shaft and the driven shaft more compact. Compared with the prior art, it reduces the axial space of the entire transmission mechanism, which is beneficial for the installation and use of the transmission mechanism on motorcycles.

[0011] Preferably, the diameters of the seventh, first, fifth, third, fourth, sixth, and second driving gears gradually increase in that order. With this arrangement, as the diameter of the driving gear increases, the torque transmitted between the driving and driven gears decreases while the transmitted speed increases. This ensures that the two driving gears with the highest torque transmission in the gear set formed by all the driving gears on the drive shaft are located at both ends of the gear set. Furthermore, the two driving gears with the highest speed transmission in the gear set on the drive shaft are also located close to the ends of the gear set. The drive shaft near the ends of the gear set is typically supported by bearings or other supporting components, thus improving the stability of the drive shaft near the ends of the gear set. This provides excellent support for the two driving gears with the highest torque and the two driving gears with the highest speed transmission, ensuring their operational stability and improving the overall reliability of the transmission mechanism.

[0012] Preferably, both ends of the third driving gear are provided with axially extending pawl portions, and the second and fourth driving gears are respectively provided with connecting holes that engage with the pawl portions of the third driving gear. With this configuration, power is transmitted by mutual fixation through the insertion of the pawl portions into the connecting holes, and power transmission is interrupted by the separation of the pawl portions from the connecting holes. Furthermore, the connecting holes reduce the weight of the gears, lower the manufacturing difficulty, and reduce the clearance between gears. This allows for convenient engagement and disengagement of the gears while simultaneously reducing the size and weight of the transmission mechanism.

[0013] Preferably, the end of the fifth drive gear is provided with a pawl portion extending axially, and the sixth drive gear is provided with a connecting hole that engages with the pawl portion of the fifth drive gear. This arrangement facilitates engagement and disengagement between gears while reducing the size and weight of the transmission mechanism.

[0014] Preferably, the seven gears of the transmission mechanism are arranged in a geometric or equal differential ratio order. This arrangement makes the lower gears of the transmission mechanism more densely packed, which facilitates smooth gear shifting at lower speeds and reduces riding jerking.

[0015] This utility model has the following beneficial effects:

[0016] 1. The shifting operation of the transmission mechanism of this utility model is achieved by two shift forks that cooperate with the gear on the drive shaft and two shift forks that cooperate with the gear on the driven shaft, thereby reducing the axial clearance space of the entire transmission mechanism and thus reducing the size of the transmission mechanism, which is beneficial for the installation and use of the transmission mechanism on motorcycles.

[0017] 2. The transmission mechanism of this utility model arranges the two low gears that transmit the largest torque and the two high gears that transmit the largest speed at both ends of the gear set of the transmission mechanism, thereby improving the reliability of the transmission mechanism under high torque and high speed conditions, and thus improving the performance of the transmission mechanism.

[0018] 3. The seven gear ratios of the transmission mechanism of this utility model are arranged in a geometric or equal differential ratio according to the gear order, so that the low gears of the transmission mechanism are arranged more densely, thereby improving the smoothness of gear shifting and reducing riding jerking when the transmission mechanism is used on an automatic transmission motorcycle, thus improving riding comfort. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of an embodiment of a seven-speed transmission mechanism for motorcycles according to the present invention;

[0020] Figure 2 for Figure 1 A schematic diagram of the drive shaft section;

[0021] Figure 3 for Figure 1 A schematic diagram of the driven shaft section. Detailed Implementation

[0022] The following detailed description illustrates the specific implementation method:

[0023] The reference numerals in the accompanying drawings include: first driving gear 1, second driving gear 2, third driving gear 3, fourth driving gear 4, fifth driving gear 5, sixth driving gear 6, seventh driving gear 7, driving shaft 8, seventh driven gear 9, sixth driven gear 10, fifth driven gear 11, fourth driven gear 12, third driven gear 13, second driven gear 14, first driven gear 15, driven shaft 16, first shift fork 17, third shift fork 18, second shift fork 19, and fourth shift fork 20.

[0024] The basic implementation examples are as follows: Figure 1 , Figure 2 and Figure 3 The diagram shows a seven-speed transmission mechanism for a motorcycle, comprising a drive shaft 8, a driven shaft 16, and a shift fork assembly. The drive shaft 8 is axially arranged with a first drive gear 1, a second drive gear 2, a third drive gear 3, a fourth drive gear 4, a fifth drive gear 5, a sixth drive gear 6, and a seventh drive gear 7. The driven shaft 16 is axially arranged with a first driven gear 15, a second driven gear 14, a third driven gear 13, a fourth driven gear 12, a fifth driven gear 11, a sixth driven gear 10, and a seventh driven gear 9. The first drive gear 1 meshes with the first driven gear 15, the second drive gear 2 meshes with the second driven gear 14, the third drive gear 3 meshes with the third driven gear 13, the fourth drive gear 4 meshes with the fourth driven gear 12, the fifth drive gear 5 meshes with the fifth driven gear 11, the sixth drive gear 6 meshes with the sixth driven gear 10, and the seventh drive gear 7 meshes with the seventh driven gear 9.

[0025] Both the first driving gear 1 and the seventh driving gear 7 are statically connected to the driving shaft 8. In this embodiment, both the first driving gear 1 and the seventh driving gear 7 are fixedly connected to the driving shaft 8 via a key, thereby allowing the driving shaft 8 to drive the first driving gear 1 and the seventh driving gear 7 to rotate. The second driving gear 2, the fourth driving gear 4, and the sixth driving gear 6 are all rotatably connected to the driving shaft 8. In this embodiment, preferably, the second driving gear 2, the fourth driving gear 4, and the sixth driving gear 6 are loosely fitted onto the driving shaft 8. The third driving gear 3 and the fifth driving gear 5 are both splined connected to the driving shaft 8, allowing both the third driving gear 3 and the fifth driving gear 5 to slide along the driving shaft 8 and rotate with it. The third driving gear 3 engages with both the second driving gear 2 and the fourth driving gear 4 via a clutch engagement, and the fifth driving gear 5 engages with both the fifth driving gear 6 via a clutch engagement. In this embodiment, both ends of the third drive gear 3 are provided with axially extending pawl portions. The second drive gear 2 and the fourth drive gear 4 are respectively provided with connecting holes that engage with the pawl portions of the third drive gear 3. Power is transmitted by inserting the pawl portions into the connecting holes, and power is disconnected by separating the pawl portions from the connecting holes. The end of the fifth drive gear 5 is provided with an axially extending pawl portion, and the sixth drive gear 6 is provided with a connecting hole that engages with the pawl portions of the fifth drive gear 5.

[0026] The first driven gear 15, the third driven gear 13, the fifth driven gear 11, and the seventh driven gear 9 are all rotatably connected to the driven shaft 16. In this embodiment, the first driven gear 15, the third driven gear 13, the fifth driven gear 11, and the seventh driven gear 9 are all loosely fitted onto the driven shaft 16. The fourth driven gear 12 is statically connected to the driven shaft 16. In this embodiment, the fourth driven gear 12 is preferably keyed to the driven shaft 16. The second driven gear 14 and the sixth driven gear 10 are both splined to the driven shaft 16. The second driven gear 14 engages with both the first driven gear 15 and the third driven gear 13. In this embodiment, both ends of the second driven gear 14 are provided with axially extending pawl portions, and both the first driven gear 15 and the third driven gear 13 are provided with connecting holes for engaging with the pawl portions. The sixth driven gear 10 engages with both the fifth driven gear 11 and the seventh driven gear 9. In this embodiment, both ends of the sixth driven gear 10 are provided with pawl portions extending axially, and the fifth driven gear 11 and the seventh driven gear 9 are provided with connecting holes that engage with the pawl portions of the sixth driven gear 10.

[0027] In this embodiment, the shift fork assembly includes a first shift fork 17 for driving the third drive gear 3, a second shift fork 19 for driving the fifth drive gear 5, a third shift fork 18 for driving the second driven gear 14, and a fourth shift fork 20 for driving the sixth driven gear 10. In this embodiment, the third drive gear 3 has a groove on its circumference that engages with the first shift fork 17. The first shift fork 17 drives the third drive gear 3 to move axially by inserting into the groove, and the third drive gear 3 can rotate relative to the first shift fork 17. Similarly, the fifth drive gear 5 has a groove on its circumference that engages with the second shift fork 19, the second driven gear 14 has a groove on its circumference that engages with the third shift fork 18, and the sixth driven gear 10 has a groove on its circumference that engages with the fourth shift fork 20.

[0028] In this embodiment, the diameters of the seventh drive gear 7, the first drive gear 1, the fifth drive gear 5, the third drive gear 3, the fourth drive gear 4, the sixth drive gear 6, and the second drive gear 2 gradually increase in size. The larger the diameter of the drive gear, the higher the gear position of the corresponding transmission mechanism, the smaller the output torque, and the higher the output speed. Therefore, the seventh drive gear 7 corresponds to the first gear of the transmission mechanism, the first drive gear 1 to the second gear, the fifth drive gear 5 to the third gear, the third drive gear 3 to the fourth gear, the fourth drive gear 4 to the fifth gear, the sixth drive gear 6 to the sixth gear, and the second drive gear 2 to the seventh gear. This arrangement ensures that the two lower-gear drive gears with the highest torque are located at both ends of the gear set, while the two higher-gear drive gears with the highest speed are also positioned close to both ends of the gear set.

[0029] The seven gears of the transmission mechanism have their speed ratios arranged in a geometric or differential order. In this embodiment, it is preferable that the seven gears of the transmission mechanism have their speed ratios arranged in a geometric order.

[0030] The specific implementation process is as follows: In neutral, all shift forks are in the middle position, and no power is transmitted between the drive shaft 8 and the driven shaft 16.

[0031] When shifting to first gear, the fourth shift fork 20 controls the engagement of the sixth driven gear 10 and the seventh driven gear 9, while the other shift forks remain in the middle position. This allows the power of the drive shaft 8 to be transmitted to the driven shaft 16 in sequence through the seventh drive gear 7, the seventh driven gear 9 and the sixth driven gear 10, thus realizing the first gear shift of the transmission mechanism.

[0032] In second gear shifting, the fourth shift fork 20 controls the sixth driven gear 10 to separate from the seventh driven gear 9 and return to the middle position, the third shift fork 18 controls the second driven gear 14 to engage with the first driven gear 15, while the other shift forks remain in the middle position, so that the power of the drive shaft 8 is transmitted to the driven shaft 16 in sequence through the first drive gear 1, the first driven gear 15 and the second driven gear 14, realizing the second gear shifting of the transmission mechanism.

[0033] When shifting to three gears, the third shift fork 18 controls the second driven gear 14 to disengage from the first driven gear 15 and return to the middle position, the fourth shift fork 20 controls the sixth driven gear 10 to engage with the fifth driven gear 11, and the other shift forks remain in the middle position, so that the power of the drive shaft 8 is transmitted to the driven shaft 16 in sequence through the fifth drive gear 5, the fifth driven gear 11 and the sixth driven gear 10, thus realizing the three-speed shifting of the transmission mechanism.

[0034] When shifting to fourth gear, the fourth shift fork 20 controls the sixth driven gear 10 to separate from the fifth driven gear 11 and return to the middle position, the third shift fork 18 controls the second driven gear 14 to engage with the third driven gear 13, and the other shift forks remain in the middle position, so that the power of the drive shaft 8 is transmitted to the driven shaft 16 in sequence through the third drive gear 3, the third driven gear 13 and the second driven gear 14, thus realizing the four-speed shifting of the transmission mechanism.

[0035] When shifting to fifth gear, the third shift fork 18 controls the second driven gear 14 to separate from the third driven gear 13 and return to the middle position, the first shift fork 17 controls the third driving gear 3 to engage with the fourth driving gear 4, and the other shift forks remain in the middle position, so that the power of the driving shaft 8 is transmitted to the driven shaft 16 in sequence through the third driving gear 3, the fourth driving gear 4 and the fourth driven gear 12, thereby realizing the five-speed shift of the transmission mechanism.

[0036] When shifting to six gears, the first shift fork 17 controls the third drive gear 3 to separate from the fourth drive gear 4 and return to the middle position, the second shift fork 19 controls the fifth drive gear 5 to engage with the sixth drive gear 6, and the other shift forks remain in the middle position, so that the power of the drive shaft 8 is transmitted to the driven shaft 16 in sequence through the fifth drive gear 5, the sixth drive gear 6 and the sixth driven gear 10, thus realizing the six-speed shifting of the transmission mechanism.

[0037] When shifting to the seventh gear, the second shift fork 19 controls the fifth drive gear 5 to separate from the sixth drive gear 6 and return to the middle position, the first shift fork 17 controls the third drive gear 3 to engage with the second drive gear 2, and the other shift forks remain in the middle position, so that the power of the drive shaft 8 is transmitted to the driven shaft 16 in sequence through the third drive gear 3, the second drive gear 2 and the second driven gear 14, thus realizing the seven-speed shifting of the transmission mechanism.

[0038] The shifting operation of the transmission mechanism of this utility model is achieved by two shift forks that cooperate with the gear on the drive shaft and two shift forks that cooperate with the gear on the driven shaft, thereby reducing the axial clearance space of the entire transmission mechanism and thus reducing the size of the transmission mechanism, which is beneficial for the installation and use of the transmission mechanism on motorcycles.

[0039] The above description is merely an embodiment of this utility model, and common knowledge such as specific structures and characteristics of the solution is not described in detail here. It should be noted that those skilled in the art can make several modifications and improvements without departing from the structure of this utility model, and these should also be considered within the protection scope of this utility model. These modifications and improvements will not affect the effectiveness of the implementation of this utility model or the practicality of the patent.

Claims

1. A seven-speed transmission mechanism for a motorcycle, comprising a drive shaft, a driven shaft, and a shift fork assembly, wherein a first drive gear, a second drive gear, a third drive gear, a fourth drive gear, a fifth drive gear, a sixth drive gear, and a seventh drive gear are sequentially arranged along the axial direction on the drive shaft, and a first driven gear, a second driven gear, a third driven gear, a fourth driven gear, a fifth driven gear, a sixth driven gear, and a seventh driven gear are sequentially arranged along the axial direction on the driven shaft, characterized in that: The first and seventh drive gears are both statically connected to the drive shaft, the second, fourth, and sixth drive gears are all rotatably connected to the drive shaft, the third and fifth drive gears are both splined connected to the drive shaft, the third drive gear engages with the second and fourth drive gears respectively, and the fifth drive gear engages with the sixth drive gear. The first driven gear, the third driven gear, the fifth driven gear, and the seventh driven gear are all rotatably connected to the driven shaft, the fourth driven gear is statically connected to the driven shaft, the second driven gear and the sixth driven gear are both splined connected to the driven shaft, the second driven gear engages with the first driven gear and the third driven gear respectively, and the sixth driven gear engages with the fifth driven gear and the seventh driven gear respectively. The shift fork assembly includes a first shift fork for driving the third driving gear, a second shift fork for driving the fifth driving gear, a third shift fork for driving the second driven gear, and a fourth shift fork for driving the sixth driven gear.

2. The motorcycle seven-speed transmission mechanism according to claim 1, characterized in that: The diameters of the seventh driving gear, the first driving gear, the fifth driving gear, the third driving gear, the fourth driving gear, the sixth driving gear, and the second driving gear gradually increase in that order.

3. The motorcycle seven-speed transmission mechanism according to claim 2, characterized in that: Both ends of the third drive gear are provided with pawl portions extending axially, and the second and fourth drive gears are respectively provided with connecting holes that engage with the pawl portions of the third drive gear.

4. A seven-speed transmission mechanism for motorcycles according to claim 3, characterized in that: The end of the fifth drive gear is provided with a pawl portion extending axially, and the sixth drive gear is provided with a connecting hole that engages and disengages with the pawl portion of the fifth drive gear.

5. A seven-speed transmission mechanism for motorcycles according to claim 4, characterized in that: The seven gear ratios of the transmission mechanism are arranged in geometric ratios or equal differential ratios according to the gear sequence.

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