Gear shifting mechanism applied to motor and gear shifting transmission mechanism

Abstract

The utility model relates to a gear shifting mechanism applied to a motor. The gear shifting mechanism comprises a cam assembly, a shifting fork assembly and a combination assembly. Wherein the cam assembly comprises a rotatable gear shifting hub, and a curved groove is formed in the surface of the gear shifting hub; the shifting fork assembly comprises a cam sleeve, a combination sleeve and a gear shifting pin. Wherein the cam sleeve is fixedly connected with the combination sleeve, the axis of the combination sleeve is parallel to the axis of the cam sleeve, the cam sleeve is arranged on a gear shifting hub in a sleeving mode, and the combination sleeve is connected with the combination assembly. The gear shifting pin is movably embedded into the cam sleeve and moves in the curve groove so as to drive the shifting fork assembly to move in the axial direction of the gear shifting hub. The combination assembly comprises a driving connecting wheel, the driving connecting wheel is rotationally connected with the combination sleeve, and the driving connecting wheel is used for being connected with other transmission mechanisms in an engaged mode. The gear shifting mechanism has the effect of being compact in structure.

Description

Technical Field

[0001] This application relates to the field of motor drive, and particularly to a shifting mechanism applied to a motor. Background Art

[0002] A power-assisted bicycle is a new type of vehicle that adds a battery and installs a motor on the basis of a traditional bicycle, enabling the bicycle to have a power assist system and realizing the integration of human power and auxiliary power. In the field of bicycles and power-assisted bicycles, in order to adapt to different road conditions, a shifting structure is usually configured. The shifting structure is usually composed of sprockets with different diameters, and the shifting is achieved by controlling the engagement of the drive chain of the power-assisted bicycle with different sprockets.

[0003] However, the power-assisted bicycle pursues light weight and integration. The existing shifting structure not only occupies a large space but also is not conducive to integration with other components of the power-assisted bicycle. Utility Model Content

[0004] In order to make the structure of the shifting mechanism more compact, this application provides a shifting mechanism applied to a motor.

[0005] A shifting mechanism applied to a motor provided by this application adopts the following technical solutions:

[0006] A shifting mechanism applied to a motor includes a cam assembly, a fork assembly, and a coupling assembly. Among them, the cam assembly includes a rotatable shifting hub, and a curve groove is formed on the surface of the shifting hub. The fork assembly includes a cam sleeve, a coupling sleeve, and a shifting pin. Among them, the cam sleeve is fixedly connected to the coupling sleeve, the axis of the coupling sleeve is parallel to the axis of the cam sleeve, the cam sleeve is sleeved on the shifting hub, the coupling sleeve is connected to the coupling assembly, and the shifting pin is movably embedded in the cam sleeve and moves in the curve groove to drive the fork assembly to move axially along the shifting hub. The coupling assembly includes a driving connection wheel, and the driving connection wheel is rotatably connected to the coupling sleeve and is used for meshing connection with other transmission mechanisms.

[0007] Optionally, a shifting mechanism applied to a motor is used for installation inside the motor.

[0008] When the shifting mechanism works, it drives the cam assembly to rotate, drives the fork assembly to move axially along the cam assembly, so that the fork assembly is combined with different gears in the shifting transmission mechanism through the coupling assembly, and the shifting action between different transmission gear sets is completed. Since the axis of the coupling sleeve is parallel to the axis of the cam sleeve, the shifting mechanism and the gears in the shifting transmission mechanism are arranged in a two-axis manner, and the structure is more compact, which is suitable for integrated installation inside the motor housing.

[0009] Optionally, multiple sets of shift fork assemblies are provided, the number of the engagement assemblies is the same as and corresponds one-to-one with that of the shift fork assemblies, and the number of the curve grooves formed on the surface of the shift hub is the same as that of the shift fork assemblies.

[0010] Optionally, multiple sets of cam assemblies are provided, and each set of the cam assemblies corresponds to at least one set of the shift fork assemblies and one set of the engagement assemblies.

[0011] To adjust the number of different gears, different numbers of cam assemblies can be provided as needed. Each set of cam assemblies can be correspondingly provided with different numbers of shift fork assemblies and engagement assemblies to achieve flexible design of the gears. Moreover, the number of gears can be expanded within the two-axis structure. By providing multiple sets of cam assemblies to increase the number of gears, the structure is expanded but still designed in a compact manner.

[0012] Optionally, the cam assembly further includes a gear-positioning boss and a gear-positioning pin; the gear-positioning boss is fixedly connected to the shift hub, a gear-positioning notch is formed in the circumferential direction of the gear-positioning boss, one end of the gear-positioning pin is connected with an elastically extendable gear-positioning member, and the gear-positioning member is in circumferential abutment with the gear-positioning boss.

[0013] Optionally, the position of the gear-positioning notch corresponds to the position where the direction of the curve groove changes.

[0014] The gear-positioning member is in circumferential abutment with the gear-positioning boss. When the gear-positioning boss rotates with the shift hub to a certain position, the gear-positioning member pops out and is engaged with the corresponding gear-positioning notch, playing a role in gear positioning and preventing the gear from disengaging due to the rotation of the shift hub caused by external force during the working process.

[0015] Optionally, the driving connection wheel has an engagement tooth disc, and the engagement tooth disc is used for meshing connection with other transmission mechanisms in the axial direction of its axis.

[0016] Optionally, the tooth profile of the engagement tooth disc is triangular, and the included angle between one tooth surface and the axis of the engagement tooth disc is 3-5 degrees.

[0017] The engagement tooth disc of the driving engagement tooth disc wheel is arranged on the end face, so that the connection with the transmission mechanism is realized in the axial direction, and the shifting mechanism and the shift transmission mechanism are arranged in a two-axis manner. The tooth profile for clutch is designed to be approximately a right triangle, and the included angle between one side and the axis is 3-5 degrees, so that shifting can be performed without stopping the motor.

[0018] Optionally, the shift fork assembly further includes a shift boss fixedly connected to the fish cam sleeve, the axis of the shift boss is perpendicular to the axis of the cam sleeve, and the shift pin is movably embedded in the shift boss.

[0019] The present application also provides a gear shift transmission mechanism, which is used in conjunction with the gear shift mechanism applied to the motor, and includes a gear shaft and multiple gears of different diameters, multiple gears are gap-connected with the gear shaft, each of the gears is fixedly connected to a driven connecting wheel, and the driven connecting wheel is used to mesh with the driving connecting wheel.

[0020] In summary, the present application includes at least one of the following beneficial technical effects:

[0021] The shift mechanism has a compact structure and is easy to install inside the motor;

[0022] The shift mechanism can adjust the number of different gears through a simple combination design;

[0023] It has the function of locking the gear to prevent the gear from coming out due to the rotation of the shift hub caused by external force during operation;

[0024] The clutch gear used for gear shifting is designed to be a structure close to a right triangle, with one side of the gear shifting at an angle of 3-5 degrees to the central axis, which can not only ensure a good gear locking effect, but also enable gear shifting without stopping the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the overall structure of a shift mechanism applied to a motor in an embodiment of the present application.

[0026] Figure 2 It is a schematic diagram of the overall structure of the cam assembly in the embodiment of the present application.

[0027] Figure 3 It is a schematic diagram of the structure of the fork assembly in the embodiment of the present application.

[0028] Figure 4 yes Figure 1 The partial enlarged view of part A is used to illustrate the structure of the fork assembly in the embodiment of the present application.

[0029] Figure 5 The motion state of the four-speed shifting function of this embodiment is shown.

[0030] Figure 6 It is a schematic diagram of the connection structure between a shift mechanism and a shift transmission mechanism applied to a motor in an embodiment of the present application.

[0031] Figure 7 yes Figure 6 A partial enlarged view of part B.

[0032] Figure 8 It is a structural cross-sectional view of a driven connecting wheel in a shifting mechanism used in a motor of the present application.

[0033] Figure 9These are various tooth profiles of the clutch gear.

[0034] Description of reference numerals: 100, cam assembly; 110, shift hub; 111, first curve groove; 112, second curve groove; 120, fixed gear boss; 130, fixed gear pin; 200, fork assembly; 210, cam sleeve; 220, coupling sleeve; 230, shift boss; 240, shift pin; 300, coupling assembly; 310, coupling wheel; 320, driving connection wheel; 400, shift transmission mechanism; 410, gear shaft; I, first gear; II, second gear; III, third gear; IV, fourth gear; 420, transmission gear; 430, driven connection wheel; 431, first tooth surface; 432, second tooth surface. Detailed implementation manners

[0035] The following Figures 1 - 9 is a further detailed description of the present application in conjunction with the attached drawings.

[0036] This embodiment discloses a shift mechanism applied to a motor, which has a four-speed shifting function.

[0037] Referring to Figure 1 , a shift mechanism applied to a motor includes a cam assembly 100, a fork assembly 200 and a coupling assembly 300. When the shift mechanism works, the cam assembly 100 is driven to rotate, driving the fork assembly 200 to move axially along the cam assembly 100, so that the fork assembly 200 is coupled with different gears in the shift transmission mechanism 400 through the coupling assembly 300 to complete the shifting action between different transmission gear sets.

[0038] Referring to Figure 2 , the cam assembly 100 is integrally in a hollow cylindrical structure, which includes an integrally formed shift hub 110 and a fixed gear boss 120. The shift hub 110 and the fixed gear boss 120 are coaxially arranged, and the outer diameter of the fixed gear boss 120 is larger than that of the shift hub 110. The shift hub 110 can rotate around its own axis. Since the shift mechanism in this embodiment has a four-speed shifting function, the outer surface of the shift hub 110 is correspondingly provided with a first curve groove 111 and a second curve groove 112, making the shift hub 110 a cylindrical cam.

[0039] Referring to Figure 1 and Figure 3, since the shift mechanism in this embodiment has the function of four-speed shifting, two sets of shift fork assemblies 200 are provided up and down. The shift fork assembly 200 includes a cam sleeve 210, a coupling sleeve 220, a shift boss 230, and a shift pin 240, wherein the cam sleeve 210, the coupling sleeve 220, and the shift boss 230 are integrally formed. The axis of the cam sleeve 210 is parallel to the axis of the coupling sleeve 220. The cam sleeve 210 is movably sleeved on the shift hub 110, and the coupling sleeve 220 is connected to the coupling assembly 300. The shift boss 230 is arranged on the outer surface of the cam sleeve 210 and is a hollow cylindrical structure. The axis of the shift boss 230 is perpendicular to the axis of the cam sleeve 210. The shift pin 240 is movably embedded in the shift boss 230 and moves in the first curve groove 111 or the second curve groove 112.

[0040] Referring to Figure 1 and Figure 4 , each set of shift fork assemblies 200 is connected to a set of coupling assemblies 300. Taking a set of coupling assemblies 300 as an example, its structure will be described in detail below. The coupling assembly 300 includes an integrally formed coupling wheel 310 and a driving connection wheel 320. The coupling sleeve 220 is coaxially sleeved on the coupling wheel 310. The coupling wheel 310 can rotate around its own axis. The driving connection wheel 320 has a coupling tooth disc, and the coupling tooth disc faces its upper and lower end faces so that the driving connection wheel 320 can mesh with the gears of other transmission mechanisms along its own axis direction. In this embodiment, the driving connection wheel 320 is a ratchet wheel with a tooth shape approximately similar to a right triangle.

[0041] Referring to the figure, when the shift mechanism works, the shift hub 110 is driven to rotate, driving the shift pin 240 in the shift fork assembly 200 to move in the curve groove of the shift hub 110. Specifically, the shift pin 240 in the upper set of shift fork assemblies 200 moves in the first curve groove 111, and the shift pin 240 in the lower set of shift fork assemblies 200 moves in the second curve groove 112. This enables the shift fork assembly 200 to linearly move along the axis of the shift hub 110. The motion states of the two sets of shift fork assemblies 200 are realized through the curve design of the first curve groove 111 and the second curve groove 112. In this embodiment, the motion states of the two sets of shift fork assemblies 200 refer to Figure 5 .

[0042] Referring to Figure 6 and Figure 7, the shift mechanism in this embodiment is used to cooperate with the shift transmission mechanism 400. The shift transmission mechanism 400 includes a gear shaft 410, a first gear I, a second gear II, a third gear III, and a fourth gear IV. The number of gears is designed according to the number of gears. The gear shaft 410 can be rotated by an external drive, and the driving connecting wheel 320 can rotate synchronously with the gear shaft 410. The first gear I, the second gear II, the third gear III, and the fourth gear IV have different diameters and are all coaxially sleeved on the gear shaft 410. When the combining assembly 300 is not engaged with the gear, the gear is in clearance fit with the gear shaft 410, that is, the rotation of the gear shaft 410 will not drive the gear to rotate. The first gear I, the second gear II, the third gear III, and the fourth gear IV are all fixedly connected with a driven connecting wheel 430. The teeth of the driven connecting wheel 430 are arranged on the gear end face, and the tooth shape is approximately a right triangle, which can be engaged and connected with the driving connecting wheel 320.

[0043] Figure 5 Shows the motion state of the four-speed function of this embodiment. The abscissa is the circumferential expansion length of the shift hub 110, and the ordinate is the axial length of the shift hub 110. It should be noted that Figure 5 It is only a schematic diagram. Only the states of the key nodes are shown in the figure, and the coordinate spacing is not equal to the actual distance. Figure 5 The broken lines a-a and b-b in the figure respectively reflect the running shapes of the first curve groove 111 and the second curve groove 112, but the actual first curve groove 111 and the second curve groove 112 are cam curve grooves with chamfers.

[0044] When the shift mechanism works, the shift hub 110 is driven to rotate, and the shift pin 240 in the fork assembly 200 moves in the curve groove. When the shift hub 110 rotates to the position of node ①, the combining assembly 300 above is engaged and connected with the first gear I, and the combining assembly 300 below is in neutral and not engaged and connected with the gear. At this time, the rotation of the gear shaft 410 drives the first gear I to rotate.

[0045] The shift hub 110 continues to rotate and rotates to the position of node ②. The combining assembly 300 above is first separated from the first gear I and then engaged and connected with the second gear II. The combining assembly 300 below is still in neutral. At this time, the rotation of the gear shaft 410 drives the second gear II to rotate.

[0046] The shift hub 110 continues to rotate and rotates to the position of node ③. The combining assembly 300 above moves to neutral after being separated from the second gear II and is not engaged and connected with the gear. The combining assembly 300 below is engaged and connected with the third gear III. At this time, the rotation of the gear shaft 410 drives the third gear III to rotate.

[0047] The shift hub 110 continues to rotate until it reaches the position of node ④. The engaging assembly 300 located above remains in the neutral position, while the engaging assembly 300 below disengages from the third gear III first and then engages with the fourth gear IV. At this time, the gear shaft 410 rotates to drive the fourth gear IV to rotate.

[0048] The shift hub 110 continues to rotate until it reaches the position of node ⑤. The engaging assembly 300 located below disengages from the fourth gear IV. At this time, neither of the upper and lower engaging assemblies 300 is connected to the gear.

[0049] Theoretically, the turning points of the a-a and b-b broken lines in the figure are the nodes where the gears engage or disengage. However, in practice, within a certain range after the driving connecting wheel 320 and the driven connecting wheel 430 start to disengage, the driving connecting wheel 320 can still drive the driven connecting wheel 430 to rotate. Therefore, nodes ① - ⑤ can deviate slightly from the turning points of the a-a and b-b broken lines.

[0050] Refer to Figure 1 and Figure 2 As shown in Figure 5 and

[0051] There is a detent notch on the outer periphery of the detent boss 120. The position of the detent notch 120 corresponds to the position where the curve groove changes its direction, and its position allows for tolerances within a reasonable range. In this embodiment, five notches are provided, and the positions of the notches correspond to the positions of nodes ① - ⑤ in

[0052] Refer to Figure 8 As shown in

[0053] Figure 9 which shows various tooth profiles. Figure 9(1) The claw - type clutch gear in the middle is the most common one in the prior art, with rectangular teeth; Figure 9 (2) - Figure 9 (5) has triangular teeth. Figure 9 (2) The tooth shape is a right - angled triangle, Figure 9 (3) The included angle between one side of the tooth shape and the central axis is 3 degrees, Figure 9 (4) The included angle between one side of the tooth shape and the central axis is 5 degrees, Figure 9 (5) The included angle between one side of the tooth shape and the central axis is 15 degrees. The following table shows the comparison of the effects of five tooth - shape structures during gear - fixing locking and separating gear - shifting. The following experiments are conducted on the five tooth - shape structures. The motor with the gear - shifting structure is integrally installed on the same - model vehicle frame, and switched to the same gear. The locking effect is tested on the same bumpy road section; the separating gear - shifting effect is tested when the motor is stopped and when the motor is running. The test results are as follows:

[0054] Tooth profile Locking effect Separation and shifting effect One Very good It is impossible to shift gears while the motor is running. The gears need to be shifted after the motor has completely stopped. Two Good When shifting gears while the motor is running, there is a sense of jerk and tooth surface damage occurs. Three Good The gears can be shifted smoothly while the motor is running. Four Good The gears can be shifted smoothly while the motor is running. Five Average The gears can be shifted smoothly while the motor is running.

[0055] When using tooth - shape one, since it has rectangular teeth, the locking effect on the gear during gear - fixing is very good, but when the motor is running, the driving connecting wheel 320 and the driven connecting wheel 430 cannot be disengaged.

[0056] When using tooth - shapes two - four, the locking effect on the gear during gear - fixing is good. Through experiments, it can still maintain the selected gear under the condition that the whole motor is vibrated. When using tooth - shapes three and four, the driving connecting wheel 320 and the driven connecting wheel 430 can be disengaged from each other when the motor is running. However, when using tooth - shape two, forced gear - shifting can be successful when the motor is running, but the tooth surface is damaged.

[0057] When using tooth - shape five, the driving connecting wheel 320 and the driven connecting wheel 430 can be smoothly disengaged from each other when the motor is running, but under the condition that the whole motor is vibrated, the foot pedal feels an instantaneous loss of motor power, and the locking effect is average.

[0058] According to the above table, in this application, the included angle between the first tooth surface 431 and the central axis of the driven connecting wheel 430 is designed to be 3 - 5 degrees, which not only ensures the gear - fixing locking effect but also enables gear - shifting without stopping the motor during motor operation.

[0059] According to the above table, in this application, the included angle between the first tooth surface 431 and the central axis of the driven connecting wheel 430 is designed to be 3 - 5 degrees, which not only ensures the gear - fixing locking effect but also enables gear - shifting without stopping the motor during motor operation.

[0060] The "coaxial", "parallel", "perpendicular", etc. described in this application all allow tolerances within a reasonable range. The above are all preferred embodiments of this application, and do not limit the protection scope of this application accordingly. Therefore, all equivalent changes made according to the structure, shape, and principle of this application should be covered within the protection scope of this application.

Claims

1. A gear shift mechanism applied to a motor, characterized in that: It includes a cam assembly, a fork assembly and a combination assembly; wherein, The cam assembly comprises a rotatable shift hub, and a curved groove is formed on the surface of the shift hub; The shift fork assembly comprises a cam sleeve, a coupling sleeve and a shift pin; wherein the cam sleeve is fixedly connected to the coupling sleeve, the axis of the coupling sleeve is parallel to the axis of the cam sleeve, the cam sleeve is sleeved on the shift hub, the coupling sleeve is connected to the coupling assembly, and the shift pin is movably embedded in the cam sleeve and moves in the curved groove to drive the shift fork assembly to move axially along the shift hub; The coupling assembly comprises an active connecting wheel, the active connecting wheel is rotatably connected to the coupling sleeve, and the active connecting wheel is used for meshing connection with other transmission mechanisms.

2. A gear shift mechanism for a motor according to claim 1, characterized in that: The fork assemblies are provided in multiple groups, the combination assemblies are the same in number and correspond one to one with the fork assemblies, and the number of the curved grooves provided on the surface of the shift hub is consistent with the number of the fork assemblies.

3. The shift mechanism for a motor according to claim 1, characterized in that: The cam assemblies are provided in a plurality of groups, and each group of the cam assemblies corresponds to at least one group of the fork assemblies and one group of the combining assemblies.

4. The gear shift mechanism for a motor according to claim 1, characterized in that: The cam assembly also includes a fixing boss and a fixing pin; the fixing boss is fixedly connected to the shift hub, the fixing boss is circumferentially provided with a fixing recess, one end of the fixing pin is connected to a fixing member that can be elastically extended, and the fixing member is circumferentially abutted against the fixing boss.

5. The shift mechanism for a motor according to claim 4, characterized in that: The position of the fixing notch corresponds to the position where the direction of the curved groove changes.

6. The shift mechanism for a motor according to claim 1, characterized in that: The active connecting wheel has a coupling toothed disc, and the coupling toothed disc is used for meshing and connecting with other transmission mechanisms in the axial direction thereof.

7. The gear shift mechanism for a motor according to claim 6, characterized in that: The tooth shape of the combined toothed disc is triangular, and the angle between one tooth surface and the central axis of the combined toothed disc is 3-5 degrees.

8. The shift mechanism for a motor according to claim 1, characterized in that: The shift fork assembly also includes a shift boss fixedly connected to the cam sleeve, the axis of the shift boss is perpendicular to the axis of the cam sleeve, and the shift pin is movably embedded in the shift boss.

9. The gear shift mechanism for a motor according to claim 1, characterized in that: It is intended to be installed inside the motor.

10. A gear shift transmission mechanism, used in conjunction with a gear shift mechanism applied to a motor as claimed in any one of claims 1 to 9, characterized in that: It comprises a gear shaft and a plurality of gears with different diameters, wherein the plurality of gears are gap-connected with the gear shaft, and each of the gears is fixedly connected with a driven connecting wheel, and the driven connecting wheel is used for meshing connection with the driving connecting wheel.

Images