阅读说明：本技术 一种五档行星自动变速器 (Five-gear planetary automatic transmission ) 是由 不公告发明人 于 2021-01-04 设计创作，主要内容包括：本发明公开一种五档行星自动变速器,包括外壳、中心齿轮、内齿圈、行星齿轮、行星架、输出轴、电机、第一齿轮塔、第二齿轮塔、输入轴、滑动架、从动齿轮、从动副齿轮、传动齿轮、驱动齿轮、驱动副齿轮、保持片、电推杆,外壳是支撑主体,输入轴可驱动第一齿轮塔旋转,第一齿轮塔通过由滑动架、第一保持杆、从动齿轮、从动副齿轮、第二保持杆、传动齿轮、驱动齿轮、驱动副齿轮、保持片构成的传动装置驱动第二齿轮塔旋转,第二齿轮塔可驱动中心齿轮转动,中心齿轮通过三个行星齿轮驱动输出轴转动,电推杆用于控制第一齿轮塔与第二齿轮塔之间传动的通断,电机通过旋转螺纹杆改变滑动架的位置,从而实现输入轴与输出轴之间的档位变换。(The invention discloses a five-gear planetary automatic transmission, which comprises a shell, a central gear, an inner gear ring, planetary gears, a planet carrier, an output shaft, a motor, a first gear tower, a second gear tower, an input shaft, a sliding frame, a driven gear, a driven pinion, a transmission gear, a driving pinion, a retaining sheet and an electric push rod, wherein the shell is a supporting main body, the input shaft can drive the first gear tower to rotate, the first gear tower drives the second gear tower to rotate through a transmission device consisting of the sliding frame, a first retaining rod, the driven gear, the driven pinion, a second retaining rod, the transmission gear, the driving pinion and the retaining sheet, the second gear tower can drive the central gear to rotate, the central gear drives the output shaft to rotate through three planetary gears, the electric push rod is used for controlling the on-off of transmission between the first gear tower and the second gear tower, and the motor changes the position of the sliding frame through, thus realizing gear shift between the input shaft and the output shaft.)

1. A five-gear planetary automatic transmission comprises a shell (1), a fourth gear (2), a central shaft (3), a central gear (4), an inner gear ring (5), a planetary gear (6), a planet carrier (7), an output shaft (8), a threaded rod (9), a motor (10), a third gear (11), a second gear tower (12), a first gear tower (13), a second bevel gear (14), a first bevel gear (15), an input shaft (16), a sliding frame (17), a first retaining rod (18), a driven gear (19), a driven pinion (19.1), a second retaining rod (20), a transmission gear (20.1), a driving gear (21), a driving pinion (21.1), a sealing cover (22), a retaining piece (23) and an electric push rod (24), and is characterized in that: the shell (1) is a supporting body, the input shaft (16) and the shell (1) form a rotating pair, and the first gear tower (13) is driven to rotate through a first bevel gear (15) and a second bevel gear (14), the first gear tower (13) drives the second gear tower (12) to rotate through a transmission device formed by a sliding frame (17), a first holding rod (18), a driven gear (19), a driven pinion (19.1), a second holding rod (20), a transmission gear (20.1), a driving gear (21), a driving pinion (21.1) and a holding sheet (23), the second gear tower (12) drives the central shaft (3) and the central gear (4) to rotate through a third gear (11) and a fourth gear (2), the central gear (4) drives the output shaft (8) to rotate through three planetary gears (6), and an electric push rod (24) is used for controlling the connection and disconnection of transmission between the first gear tower (13) and the second gear tower (12), the motor (10) is arranged on the sealing cover (22), and the position of the sliding frame (17) is changed by rotating the threaded rod (9), so that the gear change between the input shaft (16) and the output shaft (8) is realized.

2. The five-speed planetary automatic transmission according to claim 1, characterized in that: the shell (1) is a support main body of the transmission, four guide rails are obliquely arranged on two side walls in the shell, a sealing cover (22) is fixedly arranged on the left side of the shell (1) through screws, an input shaft (16) is arranged on the upper side of the shell (1) and forms a rotating pair with the shell (1) through three bearings, a first bevel gear (15) is coaxially and fixedly connected with the lower end of the input shaft (16), a central shaft (3) is arranged in the shell (1) and forms a rotating pair with the shell (1) through two bearings, a fourth gear (2) is coaxially and fixedly connected with the left end of the central shaft (3), a central gear (4) is coaxially and fixedly connected with the right end of the central shaft (3), an inner gear ring (5) is fixedly arranged in the shell (1), an output shaft (8) forms a rotating pair with the right end of the shell (1) through two bearings, and a planet carrier (, three short shafts are uniformly distributed on the left side of the planet carrier (7) in the circumferential direction, each short shaft is rotatably provided with a planetary gear (6), the three planetary gears (6) are arranged between the central gear (4) and the inner gear ring (5) and form a gear engagement relation with the central gear (4) and the inner gear ring (5), and therefore the central gear (4), the inner gear ring (5), the planet carrier (7) and the three planetary gears (6) form a planetary gear train;

the first gear tower (13) is provided with a five-layer gear structure, the reference circle diameter of the five-layer gear structure is in an equal-difference number series and forms five gears, the first gear tower (13) is arranged in the shell (1) and forms a revolute pair, the big end of the first gear tower is towards the left, the small end of the first gear tower is towards the right, a second bevel gear (14) is coaxially and fixedly connected with the left end of the first gear tower (13), the second bevel gear (14) and a first bevel gear (15) form gear meshing transmission, the parameters of the five-layer gear structure arranged on the second gear tower (12) are the same as those of the five-layer gear structure on the first gear tower (13), the second gear tower (12) is arranged in the shell (1) and forms a revolute pair, the big end of the second gear tower (12) is towards the right, the second gear tower (13) is positioned above the first gear tower (13), the central axes of the first gear tower and the second gear tower are parallel to, the third gear (11) and the fourth gear (2) form gear engagement transmission;

the sliding frame (17) is arranged inside the shell (1), two sliding block structures arranged at the left end and two sliding block structures arranged at the right end of the sliding frame (17) are respectively matched and arranged with four guide rails on two side walls inside the shell (1), so that the sliding frame (17) and the shell (1) form a moving pair, a threaded hole (17.1) is arranged at the position, close to the left end, of the sliding frame (17), a round hole (17.2) and a long slotted hole (17.3) are arranged at the position, close to the middle of the sliding frame (17), of the sliding frame, a second retaining rod (20) is arranged in the round hole (17.2) to form a rotating pair, two transmission gears (20.1) are respectively and coaxially and fixedly arranged at two ends of the second retaining rod (20), the first retaining rod (18) can slide in the long slotted hole (17.3), the driving gear (21) is positioned at the lower side between the first retaining rod (18) and the second retaining rod (, two ends of a driving gear (21) are rotationally connected with a first retaining rod (18) through two retaining pieces (23), two ends of the driving gear (21) are also rotationally connected with a second retaining rod (20) through the two retaining pieces (23), so that a driving pinion (21.1) is always meshed with a transmission gear (20.1), a driven gear (19) is positioned on the upper side between the first retaining rod (18) and the second retaining rod (20), the two driven pinions (19.1) are respectively and coaxially and fixedly arranged at two ends of the driven gear (19), two ends of the driven gear (19) are rotationally connected with the first retaining rod (18) through the two retaining pieces (23), and two ends of the driven gear (19) are also rotationally connected with the second retaining rod (20) through the two retaining pieces (23), so that the driven pinion (19.1) is always meshed with the transmission gear (20.1);

the rear end of the motor (10) is fixedly arranged on the right side of the sealing cover (22) through a screw, an output shaft of the motor (10) is fixedly connected with a threaded rod (9), the threaded rod (9) is matched and arranged with a threaded hole (17.1) to form threaded transmission, the motor (10) rotates through driving the threaded rod (9) to change the gear position of the sliding frame (17), the left end of the electric push rod (24) and the first retaining rod (18) form a rotating pair, and the right end of the electric push rod (24) is fixedly connected with the right end of the sliding frame (17);

in the initial state, the electric push rod (24) extends and pushes the first retaining rod (18) to slide towards the left in the long slotted hole (17.3), under the thrust action of the eight retaining pieces (23), the driving gear (21) moves downwards and is meshed with one gear of the first gear tower (13), and the driven gear (19) moves upwards and is meshed with a corresponding gear of the second gear tower (12).

3. The five-speed planetary automatic transmission according to claim 1, characterized in that: after a power driving input shaft (16) from an engine or a motor rotates, a first bevel gear (15) drives a first gear tower (13) to rotate through a second bevel gear (14), the first gear tower (13) drives a driving gear (21) and a driving pinion (21.1) to rotate through a gear meshing relation, the driving pinion (21.1) drives a driven pinion (19.1) and a driven gear (19) to rotate through a gear meshing relation between the driving gear (20.1) and the driven pinion (19.1), the driven gear (19) drives a second gear tower (12) and a third gear (11) to rotate through a gear meshing relation with the second gear tower (12), the third gear (11) drives a central shaft (3) and a central gear (4) to rotate through a fourth gear (2), the central gear (4) drives an output shaft (8) to rotate through three planetary gears (6) and a planet carrier (7), the output shaft (8) transmits the power to wheels or other actuating mechanisms;

when the gear needs to be changed, firstly, the electric push rod (24) contracts and pulls the first retaining rod (18) to move rightwards, under the action of the pulling force of the eight retaining pieces (23), the driving gear (21) moves upwards and is disengaged from the gear on the first gear tower (13), the driven gear (19) moves downwards and is disengaged from the gear on the second gear tower (12), then the motor (10) moves the sliding frame (17) to a proper gear through the threaded rod (9), the electric push rod (24) extends and pushes the first retaining rod (18) to move leftwards, under the action of the pushing force of the eight retaining pieces (23), the driving gear (21) moves downwards and is engaged with the corresponding gear on the first gear tower (13), and the driven gear (19) moves upwards and is engaged with the corresponding gear on the second gear tower (12), so that the gear shifting action is completed; the carriage (17) has a minimum transmission ratio at the left end of its travel suitable for high speed travel and the carriage (17) has a maximum transmission ratio at the right end of its travel suitable for low speed travel.

Technical Field

The invention relates to the field of transmissions, in particular to a five-gear planetary automatic transmission.

Background

Automatic transmissions have the advantages of easy operation, comfortable driving, and reduced driver fatigue, and have become a development direction for modern car configurations. The automobile with the automatic transmission can automatically change speed and change torque according to the road surface condition, and a driver can watch the road traffic with full attention without being confused by gear shifting operation.

Three types of automatic transmissions for automobiles are common: respectively a hydraulic Automatic Transmission (AT), a mechanical stepless automatic transmission (CVT) and an electric control mechanical automatic transmission (AMT); the AT transmission has slow response to speed change, obvious gear shift and pause feeling, relatively high oil consumption, and obviously increased volume and weight of the transmission case after the gears are increased, so that the AT transmission is restricted from developing to more gears and higher smoothness direction, and the price of the AT transmission is relatively expensive; the CVT transmission utilizes a steel belt to carry out stepless speed change, the gear shifting smoothness is good, but the manufacturing and maintenance costs are high, the upper limit of transmittable torque is low, and the transmission steel belt is easy to wear, so that the service life of the CVT transmission is limited; the technical difficulty and the manufacturing cost of the AMT transmission are relatively low, but the gear shifting and the gear shifting are strong, and the power interruption can be obviously sensed during gear shifting due to long gear shifting time, and even the situation of vehicle sliding can be caused during a slope. Most of the core patents and technologies of the existing common automatic transmissions are mastered by foreign manufacturers, so that the development of the automatic transmissions with reasonable functions, stability and reliability has obvious economic benefit and social significance.

Disclosure of Invention

In order to overcome the defects in the prior art, the invention aims to provide a five-gear planetary automatic transmission which is novel in structure and small in occupied space.

The technical scheme adopted by the invention is as follows: a five-gear planetary automatic transmission comprises a shell, a fourth gear, a central shaft, a central gear, an inner gear ring, a planetary gear, a planet carrier, an output shaft, a threaded rod, a motor, a third gear, a second gear tower, a first gear tower, a second bevel gear, a first bevel gear, an input shaft, a sliding frame, a first retaining rod, a driven gear, a driven pinion, a second retaining rod, a transmission gear, a driving pinion, a sealing cover, a retaining sheet and an electric push rod, and is characterized in that: the shell is a supporting body, the input shaft and the shell form a rotating pair, the input shaft and the shell drive a first gear tower to rotate through a first bevel gear and a second bevel gear, the first gear tower drives a second gear tower to rotate through a transmission device formed by a sliding frame, a first retaining rod, a driven gear, a driven pinion, a second retaining rod, a transmission gear, a driving pinion and a retaining sheet, the second gear tower drives a central shaft and a central gear to rotate through a third gear, a fourth gear, the central gear drives an output shaft to rotate through three planetary gears, an electric push rod is used for controlling the on-off of transmission between the first gear tower and the second gear tower, a motor is installed on a sealing cover, and the position of the sliding frame is changed through rotating a threaded rod, so that the gear change between the input shaft and the output shaft is realized.

Preferably, the housing is a support body of the transmission, four guide rails are obliquely arranged on two inner side walls of the housing, the sealing cover is tightly mounted on the left side of the housing through screws, the input shaft is mounted on the upper side of the housing and forms a rotating pair with the housing through three bearings, the first bevel gear is coaxially and tightly connected with the lower end of the input shaft, the central shaft is mounted inside the housing and forms a rotating pair with the housing through two bearings, the fourth gear is coaxially and tightly connected with the left end of the central shaft, the central gear is coaxially and tightly connected with the right end of the central shaft, the inner gear ring is fixedly mounted inside the housing, the output shaft forms a rotating pair with the right end of the housing through two bearings, the planet carrier is coaxially and tightly connected with the left end of the output shaft, three short shafts are uniformly distributed on the, and the central gear, the inner gear ring, the planet carrier and the three planetary gears form a planetary gear train.

Preferably, a fifth gear structure is arranged on the first gear tower, the reference circle diameters of the fifth gear structure are in an equal-difference series and form five gears, the first gear tower is arranged in the shell and forms a rotating pair, the large end of the first gear tower faces to the right from the small left end, the second bevel gear is coaxially and fixedly connected with the left end of the first gear tower, the second bevel gear and the first bevel gear form gear meshing transmission, the parameters of the fifth gear structure arranged on the second gear tower are the same as those of the fifth gear structure on the first gear tower, the second gear tower is arranged in the shell and forms a rotating pair, the large end of the second gear tower faces to the left from the small right end, the second gear tower is positioned above the first gear tower, the central axes of the first gear tower and the second gear tower are parallel to each other, the third gear is coaxially and fixedly connected with the right end of the second gear tower.

Preferably, the sliding frame is arranged in the shell, the two sliding block structures arranged at the left end of the sliding frame and the two sliding block structures arranged at the right end of the sliding frame are respectively matched and arranged with four guide rails on two side walls in the shell, so that the sliding frame and the shell form a moving pair, the sliding frame is provided with a threaded hole close to the left end, a round hole and a long slotted hole close to the middle position, the second retaining rod is arranged in the round hole to form a rotating pair, two transmission gears are respectively and coaxially and tightly arranged at two ends of the second retaining rod, the first retaining rod can slide in the long slotted hole, the driving gear is arranged at the lower side between the first retaining rod and the second retaining rod, two driving auxiliary gears are respectively and coaxially and tightly arranged at two ends of the driving gear, two ends of the driving gear are rotationally connected with the first retaining rod through two retaining, the driving pinion is always meshed with the transmission gear, the driven gear is located on the upper side between the first retaining rod and the second retaining rod, the two driven pinions are respectively and coaxially and fixedly mounted at two ends of the driven gear, two ends of the driven gear are rotationally connected with the first retaining rod through the two retaining pieces, and two ends of the driven gear are also rotationally connected with the second retaining rod through the two retaining pieces, so that the driven pinions are always meshed with the transmission gear.

Preferably, the rear end of the motor is fixedly mounted on the right side of the sealing cover through a screw, an output shaft of the motor is fixedly connected with a threaded rod, the threaded rod is matched with the threaded hole to be mounted to form threaded transmission, the motor rotates to change the gear position of the sliding frame through driving the threaded rod, the left end of the electric push rod and the first retaining rod form a rotating pair, and the right end of the electric push rod is fixedly connected with the right end of the sliding frame.

In an initial state, the electric push rod extends and pushes the first retaining rod to slide leftwards in the long slot hole, under the action of the pushing force of the eight retaining pieces, the driving gear moves downwards and is meshed with one gear of the first gear tower, and the driven gear moves upwards and is meshed with a corresponding gear on the second gear tower.

After the power from an engine or a motor drives an input shaft to rotate, a first bevel gear drives a first gear tower to rotate through a second bevel gear, the first gear tower enables a driving gear and a driving pinion to rotate through a gear meshing relationship, the driving pinion drives a driven pinion and a driven gear to rotate through a gear meshing relationship between the driving gear and the driven pinion, the driven gear drives a second gear tower and a third gear to rotate through a gear meshing relationship between the driven gear and the second gear tower, the third gear drives a central shaft and a central gear to rotate through a fourth gear, the central gear drives an output shaft to rotate through three planetary gears and a planetary carrier, and the output shaft transmits power to wheels or other execution mechanisms.

When gears need to be changed, firstly, the electric push rod contracts and pulls the first holding rod to move rightwards, under the action of the pulling force of the eight holding pieces, the driving gear moves upwards and is disengaged from the gear on the first gear tower, the driven gear moves downwards and is disengaged from the gear on the second gear tower, then the motor enables the sliding frame to move to a proper gear through the threaded rod, the electric push rod extends and pushes the first holding rod to move leftwards, under the action of the pushing force of the eight holding pieces, the driving gear moves downwards and is engaged with the corresponding gear on the first gear tower, and the driven gear moves upwards and is engaged with the corresponding gear on the second gear tower, so that the gear shifting action is completed; the sliding frame has the smallest transmission ratio at the left end of the stroke and is suitable for high-speed running, and the sliding frame has the largest transmission ratio at the right end of the stroke and is suitable for low-speed running.

The invention has the beneficial effects that:

firstly, when gears are changed, the driving gear is disengaged from the first gear tower, the driven gear is disengaged from the second gear tower, and then the positions of the driving gear and the driven gear are moved to change the gears, so that the transmission structure is very compact, and the problems of complex structure and large volume of a multi-gear transmission device are solved by innovative design;

the number of gears is easy to adjust, the gears can be increased by increasing the number of gears on the gear tower, the gears can be reduced by reducing the number of gears on the gear tower, the number of gears can be adjusted according to actual needs, the size of the gearbox cannot be changed greatly, and the normalization and modularization of the transmission are facilitated;

the speed changer adopts a planetary gear train speed reducing structure, and has the advantages of large transmission ratio, small volume, stable transmission, high transmission efficiency, uniform load distribution among gear teeth, strong shock and vibration resistance and the like;

the structure is compact, the occupied space is small, the volume and the weight of the whole vehicle or equipment can be effectively reduced, the energy consumption is favorably reduced, and the carbon emission is reduced.

Drawings

Fig. 1 is a schematic diagram of the overall structure of the transmission.

Fig. 2 is a schematic longitudinal sectional view of the transmission.

Fig. 3 is a schematic longitudinal sectional view of the transmission.

Fig. 4 is a partial schematic view of the shifting mechanism.

Fig. 5 is a schematic diagram of a transverse cross-sectional structure of the transmission.

Fig. 6 is a schematic diagram of a transverse cross-sectional structure of the transmission.

Fig. 7 is an exploded schematic view of the transmission.

Fig. 8 is a schematic view of the sliding frame.

Reference numerals: 1 outer shell, 2 fourth gear, 3 central shaft, 4 central gear, 5 annular gear, 6 planetary gear, 7 planet carrier, 8 output shaft, 9 threaded rod, 10 motor, 11 third gear, 12 second gear tower, 13 first gear tower, 14 second bevel gear, 15 first bevel gear, 16 input shaft, 17 sliding frame, 17.1 threaded hole, 17.2 round hole, 17.3 slotted hole, 18 first retaining rod, 19 driven gear, 19.1 driven auxiliary gear, 20 second retaining rod, 20.1 transmission gear, 21 driving gear, 21.1 driving auxiliary gear, 22 sealing cover, 23 retaining piece and 24 electric push rod.

Detailed Description

The invention will be further described with reference to the drawings and specific embodiments, which are illustrative of the invention and are not to be construed as limiting the invention.

As shown in fig. 1 to 8, a five-speed planetary automatic transmission includes a housing 1, a fourth gear 2, a center shaft 3, a sun gear 4, an internal gear 5, a planetary gear 6, a carrier 7, an output shaft 8, a threaded rod 9, a motor 10, a third gear 11, a second gear tower 12, a first gear tower 13, a second gear 14, a first bevel gear 15, an input shaft 16, a carriage 17, a first holding lever 18, a driven gear 19, a driven pinion 19.1, a second holding lever 20, a transmission gear 20.1, a driving gear 21, a driving pinion 21.1, a sealing cover 22, a holding piece 23, and an electric push rod 24, and is characterized in that: the housing 1 is a supporting body, the input shaft 16 and the housing 1 form a rotation pair, and drives the first gear tower 13 to rotate through a first bevel gear 15 and a second bevel gear 14, the first gear tower 13 drives the second gear tower 12 to rotate through a transmission device formed by a sliding frame 17, a first holding rod 18, a driven gear 19, a driven pinion 19.1, a second holding rod 20, a transmission gear 20.1, a driving gear 21, a driving pinion 21.1 and a holding sheet 23, the second gear tower 12 drives the central shaft 3 and the central gear 4 to rotate through a third gear 11 and a fourth gear 2, the central gear 4 drives the output shaft 8 to rotate through three planet gears 6, an electric push rod 24 is used for controlling the on-off of the transmission between the first gear tower 13 and the second gear tower 12, the motor 10 is installed on a sealing cover 22, and the position of the sliding frame 17 is changed by rotating the threaded rod 9, so that the gear change between the input shaft 16 and the output shaft 8 is realized.

The shell 1 is a supporting main body of the speed changer, four guide rails are obliquely arranged on two side walls inside the shell, a sealing cover 22 is tightly installed on the left side of the shell 1 through screws, an input shaft 16 is installed on the upper side of the shell 1 and forms a rotation pair with the shell 1 through three bearings, a first bevel gear 15 is coaxially and tightly connected with the lower end of the input shaft 16, a central shaft 3 is installed inside the shell 1 and forms a rotation pair with the shell 1 through two bearings, a fourth gear 2 is coaxially and tightly connected with the left end of the central shaft 3, a central gear 4 is coaxially and tightly connected with the right end of the central shaft 3, an inner gear ring 5 is fixedly installed inside the shell 1, an output shaft 8 forms a rotation pair with the right end of the shell 1 through two bearings, a planet carrier 7 is coaxially and tightly connected with the left end of the output, the three planetary gears 6 are mounted between the sun gear 4 and the ring gear 5, and are in gear engagement with the latter two, so that the sun gear 4, the ring gear 5, the planet carrier 7 and the three planetary gears 6 constitute a planetary gear train.

The first gear tower 13 is provided with five layers of gear structures, the reference circle diameters of the five layers of gear structures are in an arithmetic progression and form five gears, the first gear tower 13 is arranged in the shell 1 and forms a revolute pair, the big end is towards the left and the small end is towards the right, the second bevel gear 14 is coaxially and tightly connected with the left end of the first gear tower 13, the second bevel gear 14 and the first bevel gear 15 form gear mesh transmission, the parameters of a five-layer gear structure arranged on the second gear tower 12 are the same as those of the five-layer gear structure on the first gear tower 13, the second gear tower 12 is arranged in the shell 1 and forms a revolute pair, and the big end is left to the right tip, and second gear tower 12 is located first gear tower 13 top, and the central axis of both is parallel to each other, and third gear 11 and the coaxial fastening connection of second gear tower 12 right-hand member, third gear 11 and fourth gear 2 constitute the gear engagement transmission.

The sliding frame 17 is installed inside the casing 1, two sliding block structures arranged at the left end and two sliding block structures arranged at the right end of the sliding frame 17 are respectively installed in a matching way with four guide rails on two side walls inside the casing 1, so that the sliding frame 17 and the casing 1 form a moving pair, the sliding frame 17 is provided with a threaded hole 17.1 near the left end, a round hole 17.2 and a long slotted hole 17.3 near the middle position, a second retaining rod 20 is installed in the round hole 17.2 to form a rotating pair, two transmission gears 20.1 are respectively and coaxially and tightly installed at two ends of the second retaining rod 20, the first retaining rod 18 can slide in the long slotted hole 17.3, a driving gear 21 is positioned at the lower side between the first retaining rod 18 and the second retaining rod 20, two driving auxiliary gears 21.1 are respectively and coaxially and tightly installed at two ends of the driving gear 21, two ends of the driving gear 21 are rotatably connected with the first retaining rod 18 through two retaining pieces 23, and two ends of the driving, the driving pinion 21.1 is always meshed with the transmission gear 20.1, the driven gear 19 is positioned on the upper side between the first retaining rod 18 and the second retaining rod 20, the two driven pinions 19.1 are coaxially and fixedly arranged at two ends of the driven gear 19 respectively, two ends of the driven gear 19 are rotatably connected with the first retaining rod 18 through two retaining pieces 23, and two ends of the driven gear 19 are also rotatably connected with the second retaining rod 20 through two retaining pieces 23, so that the driven pinion 19.1 is always meshed with the transmission gear 20.1.

The rear end of the motor 10 is fixedly arranged on the right side of the sealing cover 22 through screws, an output shaft of the motor 10 is fixedly connected with the threaded rod 9, the threaded rod 9 is matched with the threaded hole 17.1 to be installed to form threaded transmission, the motor 10 rotates through driving the threaded rod 9 to change the gear position of the sliding frame 17, the left end of the electric push rod 24 and the first retaining rod 18 form a rotating pair, and the right end of the electric push rod 24 is fixedly connected with the right end of the sliding frame 17.

In the initial state, the electric push rod 24 extends and pushes the first holding rod 18 to slide to the left in the long slot hole 17.3, and under the thrust of the eight holding pieces 23, the driving gear 21 moves downward and engages with one gear of the first gear tower 13, and the driven gear 19 moves upward and engages with a corresponding one gear of the second gear tower 12.

After the power from the engine or the motor drives the input shaft 16 to rotate, the first bevel gear 15 drives the first gear tower 13 to rotate through the second bevel gear 14, the first gear tower 13 drives the driving gear 21 and the driving pinion 21.1 to rotate through the gear meshing relationship, the driving pinion 21.1 drives the driven pinion 19.1 and the driven gear 19 to rotate through the gear meshing relationship between the transmission gear 20.1 and the driven pinion 19.1, the driven gear 19 drives the second gear tower 12 and the third gear 11 to rotate through the gear meshing relationship with the second gear tower 12, the third gear 11 drives the central shaft 3 and the central gear 4 to rotate through the fourth gear 2, the central gear 4 drives the output shaft 8 to rotate through the three planet gears 6 and the planet carrier 7, and the output shaft 8 transmits the power to wheels or other execution mechanisms.

When the gear needs to be changed, firstly, the electric push rod 24 contracts and pulls the first holding rod 18 to move rightwards, under the action of the pulling force of the eight holding pieces 23, the driving gear 21 moves upwards and is disengaged from the gear on the first gear tower 13, the driven gear 19 moves downwards and is disengaged from the gear on the second gear tower 12, then after the motor 10 enables the sliding frame 17 to move to a proper gear through the threaded rod 9, the electric push rod 24 extends and pushes the first holding rod 18 to move leftwards, under the action of the pushing force of the eight holding pieces 23, the driving gear 21 moves downwards and is engaged with the corresponding gear on the first gear tower 13, and the driven gear 19 moves upwards and is engaged with the corresponding gear on the second gear tower 12, so that the gear shifting action is completed; the carriage 17 has the lowest transmission ratio at the left end of its travel, suitable for high speed travel, and the carriage 17 has the highest transmission ratio at the right end of its travel, suitable for low speed travel.

The references to "front", "back", "left", "right", etc., are to be construed as references to orientations or positional relationships based on the orientation or positional relationship shown in the drawings or as orientations and positional relationships conventionally found in use of the product of the present invention, and are intended to facilitate the description of the invention and to simplify the description, but do not indicate or imply that the device or element so referred to must have a particular orientation, be constructed and operated in a particular orientation, and is therefore not to be construed as limiting the invention. Furthermore, the terms "first," "second," and the like are used merely to distinguish one description from another, and are not to be construed as indicating or implying relative importance.