Gearbox

Abstract

The gearbox comprises a driving shaft mechanism, the driving shaft mechanism comprises a middle shaft, a transmission main gear arranged on the middle shaft in a sleeving mode and a plurality of power output gears, the transmission main gear is rotationally connected with the middle shaft, the power output gears are fixedly connected with the middle shaft in the radial direction, and the transmission main gear comprises at least one transmission branch gear; the variable-speed shaft mechanism comprises a variable-speed shaft, the variable-speed shaft is sleeved with a plurality of power receiving gears and at least one power return gear, the power receiving gears are meshed with the power output gears in a one-to-one correspondence mode, and the power return gears are meshed with the transmission branch teeth in a one-to-one correspondence mode; the gear shifting mechanism comprises a cam shaft, a gear shifting power piece and a planetary gear set, the cam shaft is coaxially arranged in an inner cavity of the speed changing shaft, the cam shaft is rotationally connected with the speed changing shaft, a gear shifting shaft is fixedly connected to one end of the cam shaft, the planetary gear set is installed on the gear shifting shaft, and a plurality of driving grooves are formed in the cam shaft in the axial direction; and a plurality of groups of ratchet meshing units are axially arranged on the variable-speed shaft.

Description

Technical Field

[0001] The present invention relates to the technical field of gearboxes, and in particular to a gearbox. Background Art

[0002] At present, the means of transportation for outdoor travel are becoming more and more diversified and intelligent, changing from the original single power source to two power sources, which can provide a better driving experience, such as new energy hybrid cars, electric-assisted bicycles, etc. However, in the specific operation, how to provide the appropriate power as the auxiliary power is particularly important, which directly affects the driving experience.

[0003] The Chinese invention patent application publication number CN116857362B discloses an electronic gearshift transmission system, which includes a box-type transmission device and an electronic gearshift control system, wherein the box-type transmission device includes a box body, a main shaft and a secondary shaft, a main shaft gear, a secondary shaft gear and a ratchet. The disadvantages of the electronic gearshift transmission system are that it is difficult to increase the number of gears due to structural limitations, the structure of the end face ratchet, the timeliness of gear switching is poor, and sometimes the middle shaft needs to be rotated before the gear is engaged, and the cam mechanism that relies on the shift fork boss on the shift fork seat to move up and down on the shift drum rod is thin, easy to wear and damage, and the elastic parts are easy to fail and difficult to replace.

[0004] In order to solve the above technical problems, the present invention provides a gearbox. The gearbox provided by the present invention can be used for rotating machinery that outputs two kinds of power simultaneously, and is not limited to hybrid vehicles and electric-assisted bicycles. Summary of the invention

[0005] The present invention aims at the technical problems existing in the prior art and provides a gearbox.

[0006] The technical solution of the present invention to solve the above technical problem is as follows: a gearbox, comprising: A drive shaft mechanism, the drive shaft mechanism comprising a central shaft and a transmission main tooth sleeved on the central shaft and a plurality of power output gears, the transmission main tooth being rotationally connected to the central shaft, the power output gear being radially fixedly connected to the central shaft, the transmission main tooth comprising at least one transmission sub-tooth; A speed change shaft mechanism, the speed change shaft mechanism comprising a speed change shaft, the speed change shaft being sleeved with a plurality of power receiving gears and at least one power return gear, the power receiving gears being meshed with the power output gears in a one-to-one correspondence, and the power return gears being meshed with the transmission teeth in a one-to-one correspondence; The gear shifting mechanism comprises a camshaft, a gear shifting power member and a planetary gear set, the camshaft being coaxially arranged in the inner cavity of the speed shifting shaft, the camshaft being rotatably connected to the speed shifting shaft, one end of the camshaft being fixedly connected to a shifting shaft, the planetary gear set being mounted on the shifting shaft, a plurality of driving grooves being axially arranged on the camshaft, a plurality of groups of ratchet meshing units being axially arranged on the speed shifting shaft, the driving grooves corresponding to the ratchet meshing units one by one, each of the power receiving gear and the power return gear being provided with internal teeth, each of the power receiving gear and the power return gear being correspondingly matched with a group of ratchet meshing units, the gear shifting power member transmitting power to the camshaft through the planetary gear set and the shifting shaft, the camshaft rotating to change the state of the ratchet meshing unit to realize a radially fixed connection between a power receiving gear and a power return gear and the speed shifting shaft.

[0007] Preferably, in the above-mentioned gearbox, a torque sensor is installed on the main transmission gear.

[0008] Preferably, in the above-mentioned gearbox, the ratchet engagement unit includes a ratchet, an elastic wire ring, and a ratchet cavity, a plurality of annular grooves are provided on the outside of the speed change shaft, the elastic wire ring is embedded in the annular grooves, and the ratchet is installed in the ratchet cavity.

[0009] Preferably, in the above-mentioned gearbox, the ratchet includes a brake foot, a rotating table, an engaging portion and a prying groove, the elastic wire ring passes through the prying groove to bind the ratchet in the ratchet cavity, the engaging portion is used to engage with the internal teeth of the power receiving gear and the power return gear, and a through hole is provided at the bottom of the ratchet cavity, the brake foot passes through the through hole and can swing in the through hole, and the driving groove is used to drive the brake foot to swing around the rotating table.

[0010] Preferably, in the above-mentioned gearbox, the planetary gear set includes a planetary wheel carrier, a fixed outer ring gear, and a rotatable shift ring gear, the planetary wheel carrier is rotatably connected to the shift shaft, two sets of planetary transmission mechanisms are installed on the planetary wheel carrier, the shift shaft is installed with a sun gear A and a sun gear B, the sun gear A and the sun gear B are meshed with the two sets of planetary transmission mechanisms in a one-to-one correspondence, and the shift ring gear is provided with shift ring internal teeth, one set of planetary transmission mechanisms is meshed with the outer ring gear, and the other set of planetary transmission mechanisms is meshed with the inner teeth of the shift ring gear.

[0011] Preferably, in the above-mentioned gearbox, a limiting groove is provided on the camshaft, a limiting column is installed on the speed change shaft, and the limiting column is inserted into the limiting groove.

[0012] Preferably, in the above-mentioned gearbox, a toothed disc is fixed on the main transmission teeth.

[0013] Preferably, in the above-mentioned gearbox, the shift shaft is fixedly connected to the sun gear B in a radial direction, and the shift shaft is rotationally connected to the sun gear A in a radial direction.

[0014] Preferably, in the above-mentioned gearbox, a fixed ring is fixed on the speed change shaft, the sun gear A is fixedly connected to the fixed ring, the fixed ring is rotationally connected to the shift shaft, and the sun gear A, the fixed ring and the speed change shaft are coaxially arranged.

[0015] Preferably, in the above-mentioned gearbox, the shift gear ring is provided with shift gear ring external teeth, the shift power member is a shift motor, a driving gear is installed on the output shaft of the shift motor, and the driving gear is meshed with the shift gear ring external teeth.

[0016] The beneficial effects of the present invention are: 1. The gearbox provided by the present invention has a simple structure and timely gear shift response, and is easy to assemble and process the entire gearbox and reduces the difficulty of subsequent maintenance.

[0017] 2. The gearbox provided by the present invention has an integrated torque sensor inside. When applied to an electric-assisted bicycle, the rider's pedaling frequency and pedaling torque can be collected throughout the entire process. The collected rider's pedaling frequency and pedaling torque information is transmitted to the control board of the electric-assisted bicycle through the torque sensor. The control board can accurately analyze how much electric assistance the rider needs, and output corresponding power through the motor, thereby improving the riding experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a three-dimensional diagram of the internal structure of the present invention.

[0019] Figure 2 It is a three-dimensional diagram of the speed change shaft mechanism of the present invention.

[0020] Figure 3 It is an internal cross-sectional view of the speed change shaft mechanism of the present invention.

[0021] Figure 4 It is an exploded schematic diagram of some components of the speed change shaft mechanism of the present invention.

[0022] Figure 5 It is a three-dimensional schematic diagram of some components of the speed change shaft mechanism of the present invention.

[0023] Figure 6 is a three-dimensional diagram of the ratchet of the present invention.

[0024] Figure 7 It is a structural schematic diagram of the transmission main gear of the present invention.

[0025] Figure 8 It is a schematic diagram of the external structure of the present invention.

[0026] Fig. 9 It is a structural schematic diagram of the present invention applied to an electric power-assisted bicycle.

[0027] Fig.10 It is a partial schematic diagram of the handlebar position when the present invention is applied to an electric power-assisted bicycle.

[0028] In the accompanying drawings, the components represented by the reference numerals are listed as follows: 60. Electric bicycle, 61. Crank, 62. Gearbox, 63. Tooth plate, 64. Hub motor, 65. Stopwatch, 66. Turnbar, 67. Middle shaft, 68. Transmission gear A, 69. Transmission gear B, 70. Transmission gear C, 71. Transmission main gear, 72. Torque sensor, 721. Strain gauge, 722. Torque sensor control board, 723. Plastic cover, 725. Coil sleeve, 7251. Limit foot, 726. Shield cover, 727. Communication line, 73. Shift gear ring, 74. Planetary gear set, 75. Shift motor, 76. Shift gear A, 77. Shift gear B, 78. Shift gear C, 79. Shift gear D, 80. Shift gear E, 81. Spacer, 82. Speed ​​change shaft, 821, ratchet cavity position, 83, ratchet, 831, brake foot, 832, rotating table, 833, disengage groove, 834, meshing part, 84, elastic wire ring, 85, limit column, 86, camshaft, 861, driving groove, 862, limit groove, 87, shift shaft, 88, pin shaft, 89, fixed ring, 90, planetary wheel carrier, 91, outer gear ring, 92, planetary wheel shaft, 93, planetary wheel, 94, sun gear A, 95, sun gear B, 96, deep groove ball bearing, 97, open retaining ring, 98, sealing ring, 99, left cover, 100, middle cover, 101, right cover, 102, chain, 103, flywheel, 104, pedal, 105, bicycle five-way. DETAILED DESCRIPTION

[0029] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0030] like Figures 1 to 8 As shown, a gearbox includes a drive shaft mechanism, a speed change shaft mechanism, and a gear shift mechanism. The gearbox housing is composed of a left cover 99, a middle cover 100, and a right cover 101. The left cover 99, the middle cover 100, and the right cover 101 are connected by screws to surround the internal structure of the gearbox 62.

[0031] The drive shaft mechanism includes a central shaft 67, a transmission main tooth 71 sleeved on the central shaft 67, and three power output gears. The central shaft 67 passes through the interior of the transmission main tooth 71. The transmission main tooth 71 is rotatably connected to the central shaft 67. The central shaft 67 supports the transmission main tooth 71 through a needle bearing. The transmission main tooth 71 includes two transmission split teeth. The power output gear is fixedly connected to the central shaft 67 in the radial direction. The three power output gears are transmission tooth A68, transmission tooth B69, and transmission tooth C70. The inner rings of transmission tooth A68, transmission tooth B69, and transmission tooth C70 are spline structures. A part of the central shaft 67 is a spline shaft. The transmission tooth A68, transmission tooth B69, and transmission tooth C70 are connected to the central shaft 67 through splines. A toothed disc 63 is fixed on the transmission main tooth 71 for transmitting power.

[0032] The speed-changing shaft mechanism includes a speed-changing shaft 82, on which three power receiving gears and two power return gears are sleeved. The three power receiving gears and the two power return gears can be engaged and disengaged through ratchet teeth 83. When disengaged, they are rotationally connected with the speed-changing shaft 82, and when engaged, they have the same angular velocity as the speed-changing shaft 82. The three power receiving gears are speed gear A 76, speed gear B 77, and speed gear C 78, and the two power return gears are speed gear D 79 and speed gear E 80. The speed gear A 76, the speed gear B 77, the speed gear C 78, the speed gear D 79, and the speed gear E 80 have both internal teeth and external teeth. The speed gear A 76, the speed gear B 77, the speed gear C 78, the speed gear D 79, and the speed gear E 80 are meshed with the two transmission partial teeth of the transmission tooth A 68, the transmission tooth B 69, the transmission tooth C 70, and the transmission main tooth 71.

[0033] The shift mechanism includes a camshaft 86, a shift motor 75, and a planetary gear set 74. The camshaft 86 is coaxially arranged in the inner cavity of the speed change shaft 82, and the camshaft 86 is rotatably connected to the speed change shaft 82. One end of the camshaft 86 is fixedly connected to the shift shaft 87 through a pin 88. The planetary gear set 74 is installed on the shift shaft 87. The planetary gear set 74 includes a planetary wheel carrier 90, a fixed outer gear ring 91, and a rotatably arranged shift gear ring 73. The planetary wheel carrier 90 is rotatably connected to the shift shaft 87, the outer gear ring 91 is fixed on the right cover 101, and a deep groove ball bearing 96 is installed between the planetary wheel carrier 90 and the shift shaft 87. A fixed ring 89 is fixed on the speed change shaft 82, and the sun gear A94 is fixedly connected to the fixed ring 89, and the fixed ring 89 is rotatably connected to the shift shaft 87. The sun gear A94, the fixed ring 89, and the speed change shaft 82 are coaxially arranged. Two planetary transmission mechanisms are installed on the planetary gear carrier 90. The two planetary transmission mechanisms share one planetary gear carrier 90. The planetary group 74 has four groups of planetary gears 93. Each group of planetary gears 93 shares one planetary gear shaft 92. The planetary gears 93 are installed on the planetary gear shaft 92 through an open retaining ring 97. The two planetary gears 93 in each group can rotate freely relative to each other. The shift shaft 87 is installed with a sun gear A94 and a sun gear B95. The sun gears A94 and B95 are respectively engaged with the two groups of planetary transmission mechanisms. The shift shaft 87 can rotate freely in the sun gear A94. A sealing ring 98 is arranged between the shift shaft 87 and the sun gear A94. The middle of the sun gear B95 is a polygonal hole. The head of the shift shaft 87 is the same polygonal shaft. The sun gear B95 is connected to the shift shaft 87 through a polygonal structure. The sun gear B95 and the shift shaft 87 have the same angular velocity.

[0034] The gear ring 73 is provided with outer gear ring teeth and inner gear ring teeth, one set of planetary transmission mechanisms meshes with the outer gear ring 91, and the other set of planetary transmission mechanisms meshes with the inner gear ring teeth. A driving gear is mounted on the output shaft of the gear motor 75, and the driving gear meshes with the outer gear ring teeth. The gear ring 73 is sleeved on the outer cylinder on the right cover 101 and can rotate freely.

[0035] When the speed change shaft 82 rotates, the sun gear A 94 drives the planetary gear 93 of the lower layer of the planetary group 74 to rotate. The rotation of the planetary gear 93 of the lower layer of the planetary group 74 drives the planetary carrier 90 to rotate. The rotation of the planetary carrier 90 drives the planetary gear 93 of the upper layer to rotate, thereby driving the sun gear B 95 to rotate. Since the sun gear B 95 and the shift shaft 87 have the same angular velocity, the shift shaft 87 also rotates together. Therefore, when the speed change shaft 82 rotates, the shift shaft 87 also rotates together.

[0036] When the shift motor 75 drives the shift ring gear 73 to rotate, the rotation of the shift ring gear 73 can drive a layer of planetary gears 93 on the planetary group 74 to rotate, the rotation of a layer of planetary gears 93 on the planetary group 74 can drive the sun gear B 95 to rotate, the rotation of the sun gear B95 can drive the shift shaft 87 to rotate, the rotation of the shift shaft 87 can drive the camshaft 86 to rotate, and the rotation of the camshaft 86 relative to the speed shaft 82 is the execution action of the shift. Because the upper and lower layers of planetary gears 93 of the planetary group 74 can rotate freely relative to each other, the gear shift and the rotation of the speed shaft 82 do not affect each other.

[0037] The camshaft 86 is axially provided with a plurality of driving grooves 861 of different shapes and depths, and the speed change shaft 82 is axially provided with a plurality of ratchet meshing units, and the driving grooves 861 correspond to the ratchet meshing units one by one. Each power receiving gear and power return gear is matched with a set of ratchet meshing units. When the shift motor 75 rotates, the power is transmitted to the camshaft 86 through the planetary gear set 74 and the shift shaft 87. The rotation of the camshaft 86 changes the state of the ratchet meshing unit to realize a radial fixed connection between a power receiving gear and a power return gear and the speed change shaft 82. At the same time, there is only one power receiving gear and one power return gear radially fixedly connected to the speed change shaft 82 at a time. The gearbox can realize a three-by-two six-speed shift. The spacer 81 is sleeved on the outer end of the speed change shaft 82 to isolate the speed change shaft 82 from the gearbox housing.

[0038] A limiting groove 862 is provided on the camshaft 86, and a limiting post 85 is installed on the speed change shaft 82, and the limiting post 85 is inserted into the limiting groove 862. The camshaft 86 can rotate inside the speed change shaft 82, but the camshaft 86 cannot rotate arbitrarily inside the speed change shaft 82, and has a rotation range, which is controlled by the limiting post 85 and the limiting groove 862 of the camshaft 86, wherein the limiting post 85 has an external thread and can be fixed on the speed change shaft 82, and the limiting post 85 has a cylindrical head, and the cylindrical head of the limiting post 85 extends into the limiting groove 862 to play a limiting role.

[0039] The ratchet meshing unit includes a ratchet 83, an elastic wire ring 84, and a ratchet cavity 821. The outer portion of the speed change shaft 82 is provided with a plurality of annular grooves, the elastic wire ring 84 is embedded in the annular grooves, and the ratchet 83 is installed in the ratchet cavity 821. The ratchet 83 includes a brake foot 831, a rotating platform 832, an engagement portion 834, and a disengagement groove 833. The disengagement and retraction of the ratchet 83 is a rotational movement of the ratchet 83 around the center of its rotating platform 832. The elastic wire ring 84 passes through the disengagement groove 833 to bind the ratchet 83 in the ratchet cavity 821. The ratchet 83 is pressed into the disengagement groove 833 of the ratchet 83 by the elastic wire ring 84 and is sleeved on the groove of the speed change shaft 82 together, which can not only prevent the ratchet 83 from falling out of the ratchet cavity 821 on the speed change shaft 82, but also because of the elasticity of the elastic wire ring 84 itself, it can always press the ratchet 83, so that the ratchet 83 is always kept in the disengagement state. When the ratchet 83 is fully retracted, the ratchet 83 will be completely hidden in the ratchet cavity 821 on the speed change shaft 82, and the gear matched with the ratchet 83 can rotate freely relative to the speed change shaft 82. The meshing portion 834 is used to mesh with the internal teeth of the power receiving gear and the power return gear. The bottom of the ratchet cavity 821 is provided with a through hole, and the brake foot 831 passes through the through hole and can swing in the through hole. The driving groove 861 is used to drive the brake foot 831 to swing around the rotating table 832. When the camshaft 86 rotates, the brake foot 831 of the ratchet 83 performs a cam motion in the driving groove 861 opposite to the camshaft 86, and cooperates with the elastic wire ring 84 to control the opening and closing of the ratchet 83. The rotation of the camshaft 86 and the elasticity of the elastic wire ring 84 can drive the opening and closing of the ratchet 83. The opening and closing of the ratchet 83 determines whether the speed gear A76, the speed gear B77, the speed gear C78, ​​the speed gear D79, the speed gear E80 and the speed shaft 82 have the same angular velocity, and also determines which gear the transmission is in, and the gear shift response is timely.

[0040] The transmission main tooth 71 is equipped with a torque sensor 72. Specifically, a strain gauge 721 of the torque sensor 72 is arranged on the transmission main tooth 71, and the strain gauge 721 can capture the tiny rigid deformation of the transmission main tooth 71 itself. An induction coil is arranged on the coil sleeve 725, and the induction coil is surrounded by a shielding cover 726. The different rigid deformations of the transmission main tooth 71 itself can affect the generation of different electrical signals between the strain gauge 721 and the induction coil arranged on the coil sleeve 725, and transmit them to the torque sensor control board 722 of the torque sensor 72. The torque sensor control board processes the electrical signal and transmits it through the communication line 727. The outside of the torque sensor 72 is a plastic cover 723, and the limit foot 7251 on the coil sleeve is stuck on the left cover 99, so that the transmission main tooth 71 can rotate freely at the center of the torque sensor 72.

[0041] The following embodiments are described in conjunction with the application of the gearbox in an electric power-assisted speed-changing bicycle.

[0042] like Fig. 9 , Fig.10 As shown, the electric-assisted bicycle 60 is equipped with a rear hub motor 64, and a gearbox 62 is installed at the position of the bicycle's five-way bracket 105. The gearbox 62 can collect the rider's pedaling frequency and torque during pedaling through the torque sensor 72 arranged inside it. The torque sensor 72 converts the collected pedaling frequency and torque during pedaling into electrical signals and transmits them to the control board of the electric-assisted bicycle. The chip in the control board of the electric-assisted bicycle 60 analyzes the signal transmitted by the torque sensor through a software algorithm, and issues instructions to the rear hub motor 64. The rear hub motor 64 of the electric-assisted bicycle 60 determines how much electric assistance to provide to the bicycle based on the received instructions.

[0043] When the rider does not need the power provided by the electric-assisted bicycle 60, the rider provides power to the electric-assisted bicycle 60 by pedaling on the pedals 104, wherein the pedals 104 are fixed on the cranks 61, the cranks 61 are fixed on the central axis 67 of the gearbox 62, and the chainrings 63 of the electric-assisted bicycle 60 are fixed on the main transmission teeth 71 of the gearbox 62. The gearbox 62 can convert the power provided by the rider's pedaling into the main transmission teeth 71, and the main transmission teeth 71 drive the chainrings 63 to rotate, the chainrings 63 drive the chain 102 to move, and the chain 102 drives the flywheel 103 to rotate, and finally drives the rear wheel of the electric-assisted bicycle 60 to rotate, so that the electric-assisted bicycle 60 starts.

[0044] Fig.10 A partial stereoscopic diagram of the handlebar position of an electric power-assisted bicycle 60 is shown. The operating button of the shift mechanism of the gearbox 62 is arranged on the turning handle 66. The turning handle 66 may be one button or multiple buttons. The rider switches gears by pressing the button on the turning handle 66. At the same time, when the button on the turning handle 66 is pressed, a mechanical vibration feedback can be provided to the rider's pressing finger, and there is also a short prompt tone. At the same time, the number of gears will be displayed on the code meter 65, giving the rider a sufficient shifting experience. The shift mechanism is an electronic shift, and the control system can accurately control the rotational angular displacement of the shift motor, thereby accurately controlling the angular displacement of the camshaft to achieve precise shifting. It can achieve a high number of gears while having a compact structure, can reduce the total weight of the electric power-assisted bicycle, and is easy to operate.

[0045] Similarly, when the gearbox is used in a hybrid vehicle, the output shaft of the engine is connected to the middle shaft 67, and the torque output through the speed change is transmitted to the sprocket 63. The sprocket 63 transmits the power to the wheel axle of the vehicle through the power transmission mechanism. The gearbox 62 can collect the engine speed and torque through the torque sensor 72 arranged inside it. The torque sensor 72 converts the collected data into electrical signals and transmits them to the control board. The chip in the control board analyzes the signal transmitted by the torque sensor through the software algorithm, analyzes how much electric power the vehicle needs, and issues instructions to the vehicle's motor. The motor decides how much electric power to provide to the vehicle based on the received instructions.

[0046] In the description of the present invention, it should be understood that the terms "upper", "lower", "left", "right", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, and a specific direction structure and operation, and therefore, cannot be understood as a limitation of the present invention. In addition, "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0047] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", etc. should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0048] The above is a detailed description of an embodiment of the present invention, but the content is only a preferred embodiment of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A gearbox, characterized in that: include: A drive shaft mechanism, the drive shaft mechanism comprising a central shaft (67), a transmission main tooth (71) sleeved on the central shaft (67), and a plurality of power output gears, the transmission main tooth (71) being rotationally connected to the central shaft (67), the power output gear being radially fixedly connected to the central shaft (67), and the transmission main tooth (71) comprising at least one transmission tooth; A speed change shaft mechanism, the speed change shaft mechanism comprising a speed change shaft (82), the speed change shaft (82) being sleeved with a plurality of power receiving gears and at least one power return gear, the power receiving gears being meshed with the power output gears in a one-to-one correspondence, and the power return gears being meshed with the transmission teeth in a one-to-one correspondence; A shift mechanism, the shift mechanism comprising a camshaft (86), a shift power member, and a planetary gear set (74); the camshaft (86) is coaxially arranged in an inner cavity of the speed change shaft (82); the camshaft (86) is rotationally connected to the speed change shaft (82); one end of the camshaft (86) is fixedly connected to a shift shaft (87); the planetary gear set (74) is mounted on the shift shaft (87); a plurality of drive grooves (861) are axially arranged on the camshaft (86); and a plurality of groups of ratchet teeth are axially arranged on the speed change shaft (82). The driving groove (861) corresponds to the ratchet meshing unit one by one, each of the power receiving gear and the power return gear is provided with internal teeth, each of the power receiving gear and the power return gear is matched with a group of ratchet meshing units, the shift power member transmits power to the camshaft (86) through the planetary gear set (74) and the shift shaft (87), and the camshaft (86) rotates to change the state of the ratchet meshing unit to achieve a radial fixed connection between a power receiving gear and a power return gear and the shift shaft (82).

2. The gearbox according to claim 1, characterized in that: A torque sensor (72) is mounted on the main transmission tooth (71).

3. The gearbox according to claim 1, characterized in that: The ratchet meshing unit comprises a ratchet (83), an elastic wire ring (84), and a ratchet cavity (821); a plurality of annular grooves are provided on the outside of the speed change shaft (82); the elastic wire ring (84) is embedded in the annular grooves; and the ratchet (83) is installed in the ratchet cavity (821).

4. The gearbox according to claim 3, characterized in that: The ratchet (83) comprises a brake foot (831), a rotating platform (832), an engaging portion (834) and a disengaging groove (833); the elastic wire ring (84) passes through the disengaging groove (833) to bind the ratchet (83) in the ratchet cavity (821); the engaging portion (834) is used to mesh with the internal teeth of the power receiving gear and the power return gear; a through hole is provided at the bottom of the ratchet cavity (821); the brake foot (831) passes through the through hole and can swing in the through hole; and the driving groove (861) is used to drive the brake foot (831) to swing around the rotating platform (832).

5. The gearbox according to claim 1, characterized in that: The planetary gear set (74) comprises a planetary wheel carrier (90), a fixed outer ring gear (91), and a rotatable shift ring gear (73); the planetary wheel carrier (90) is rotatably connected to the shift shaft (87); two sets of planetary transmission mechanisms are mounted on the planetary wheel carrier (90); a sun gear A (94) and a sun gear B (95) are mounted on the shift shaft (87); the sun gear A (94) and the sun gear B (95) are meshed with the two sets of planetary transmission mechanisms in a one-to-one correspondence; the shift ring gear (73) is provided with shift ring gear inner teeth, one set of the planetary transmission mechanisms meshes with the outer ring gear (91), and the other set of the planetary transmission mechanisms meshes with the shift ring gear inner teeth.

6. The gearbox according to claim 4, characterized in that: A limiting groove (862) is provided on the camshaft (86), a limiting column (85) is installed on the speed change shaft (82), and the limiting column (85) is inserted into the limiting groove (862).

7. The gearbox according to claim 1, characterized in that: A toothed disc (63) is fixed on the main transmission tooth (71).

8. The gearbox according to claim 5, characterized in that: The shift shaft (87) is radially fixedly connected to the sun gear B (95), and the shift shaft (87) is radially rotationally connected to the sun gear A (94).

9. The gearbox according to claim 8, characterized in that: A fixing ring (89) is fixed on the speed change shaft (82), the sun gear A (94) is fixedly connected to the fixing ring (89), the fixing ring (89) is rotationally connected to the shift shaft (87), and the sun gear A (94), the fixing ring (89) and the speed change shaft (82) are coaxially arranged.

10. The gearbox according to claim 5, characterized in that: The gear shift ring (73) is provided with gear shift ring external teeth, the gear shift power component is a gear shift motor (75), an output shaft of the gear shift motor (75) is provided with a driving gear, and the driving gear is meshed with the gear shift ring external teeth.

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