Gearbox and electric loader

Abstract

The utility model provides a gearbox and an electric loader, which belong to the technical field of vehicles, and comprise an input shaft, a primary speed reduction planet row, a secondary speed reduction planet row, a brake and a secondary speed reduction transmission system, the first-stage speed reduction planet row is coaxially connected to the input shaft, the input shaft can directly drive the first-stage speed reduction planet row to rotate, and a planet carrier of the first-stage speed reduction planet row is connected or disconnected with the input shaft through a clutch; the input shaft is sleeved with the second-stage speed reduction planet row in an empty mode, and the second-stage speed reduction planet row and the first-stage speed reduction planet row share the planet carrier; the second-stage speed reduction planet row transmits power through the first-stage speed reduction planet row; the brake controls the planet carrier to brake; the second-stage speed reduction transmission system is meshed with the second-stage speed reduction planet row; power decelerated by the second-stage speed reduction transmission system is transmitted to wheels through a drive axle; the transmission ratio i1 of the second-stage reduction transmission system is larger than or equal to 5. Due to the adoption of the high-speed-ratio gearbox driven by the high-speed motor, the working efficiency and the running speed can be improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of vehicles, and in particular relates to a large-speed ratio gearbox and an electric loader. Background Art

[0002] Pure electric loaders are tire loaders, and their mainstream technology utilizes dual motors: a travel motor and a hydraulic motor. The travel motor drives the gearbox, which transmits power to the drive axle wheels; the hydraulic motor drives the hydraulic pump, which performs steering, working, and brake light functions.

[0003] Currently, pure electric loaders typically use a single low-speed motor driving a small-ratio gearbox (the first gear ratio is generally between 2 and 3). Compared to high-speed motors, low-speed motors have lower peak efficiency, are larger and heavier, and have slower response speeds. As the loading capacity of pure electric loaders increases, there is an urgent need for a high-ratio gearbox to improve their operating efficiency and response speed. Utility Model Content

[0004] The embodiments of the present invention provide a high-speed ratio gearbox and an electric loader, aiming to solve the problems of low operating efficiency, slow response speed, large size and weight of the current low-speed motor-driven low-speed ratio gearbox.

[0005] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is to provide a gearbox, comprising:

[0006] Input shaft;

[0007] A first-stage reduction planetary gear is coaxially connected to the input shaft, and a planet carrier of the first-stage reduction planetary gear is engaged with or disconnected from the input shaft via a clutch;

[0008] A secondary reduction planetary gear is loosely mounted on the input shaft, and the secondary reduction planetary gear and the primary reduction planetary gear share the same planet carrier;

[0009] a brake for controlling the braking of the planetary carrier; and

[0010] A two-stage reduction transmission system is engaged with the two-stage reduction planetary gear. The power decelerated by the two-stage reduction transmission system is transmitted to the wheels via the drive axle. The transmission ratio i1 of the two-stage reduction transmission system is ≥5.

[0011] In combination with the first aspect, in one feasible manner, the first-stage reduction planetary gear includes a first-stage sun gear coaxially connected to the input shaft and a first-stage planetary gear mounted on the planetary carrier, and the first-stage planetary gear is meshed with the first-stage sun gear; the second-stage reduction planetary gear includes a second-stage sun gear loosely mounted on the input shaft and a second-stage planetary gear mounted on the planetary carrier, and the second-stage planetary gear is meshed with the second-stage sun gear; the second-stage reduction transmission system is meshed with the second-stage sun gear; the second-stage planetary gear and the first-stage planetary gear constitute a duplex gear.

[0012] In combination with the first aspect, in one feasible manner, the two-stage reduction transmission system includes a first-stage reduction gear set and a second-stage reduction gear set, the first-stage reduction gear set is loosely mounted on the input shaft, the first-stage reduction gear set and the second-stage reduction gear set are connected via an intermediate shaft, and the second-stage reduction gear set is connected to the drive axle.

[0013] In combination with the first aspect, in one feasible manner, the first-stage reduction gear set includes a first-stage driving gear and a first-stage driven gear meshing with each other, the first-stage driving gear is loosely mounted on the input shaft, and the first-stage driving gear is connected to the second-stage sun gear; the first-stage driven gear is coaxially connected to the intermediate shaft.

[0014] In combination with the first aspect, in one achievable manner, the secondary sun gear and the primary driving gear are both connected to a hollow shaft, and the hollow shaft is loosely sleeved on the input shaft.

[0015] In combination with the first aspect, in one achievable manner, the secondary reduction gear set includes a secondary driving gear and a meshingly connected secondary driven gear, the secondary driving gear is coaxially connected to the intermediate shaft, and the secondary driven gear is connected to the drive axle.

[0016] In combination with the first aspect, in one achievable manner, the transmission ratio i1 of the two-stage reduction transmission system is ≥10.

[0017] In combination with the first aspect, in one achievable manner, the outer hub of the clutch is connected to the planetary carrier, and the inner hub of the clutch is connected to the input shaft.

[0018] The utility model provides a large speed ratio gearbox. Compared with the existing technology, the beneficial effects are: the cooperation of the two-stage planetary reduction and the two-stage reduction transmission system can obtain a larger driving speed ratio, the speed is reduced and the torque is increased during operation, and a larger torque output is provided, a higher load capacity is provided, and a larger external load is withstood. It is suitable for working conditions that need to carry large loads, such as heavy-duty lifting machinery, engineering machinery, etc., and can ensure the reliability and stability of the transmission; when driving, it can provide high speed and low torque, provide sufficient vehicle speed for the whole machine, thereby improving the operating efficiency and driving speed of the whole machine; the two reduction planetary gears share the planetary carrier, which is conducive to saving space, reducing the size and weight of the gearbox, reducing the production cost, and also conducive to the miniaturization of the gearbox.

[0019] In a second aspect, an embodiment of the present invention further provides an electric loader, comprising the gearbox and a high-speed motor driving the gearbox.

[0020] The electric loader provided by the embodiment of the present invention adopts a large-speed ratio gearbox driven by a high-speed motor, which can provide a high-torque and low-speed working state when working, and can provide a high-speed and low-torque working state when driving, providing sufficient traction and vehicle speed for the entire machine. Therefore, it can improve working efficiency and driving speed, and at the same time can be flexibly arranged to reduce production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A schematic diagram of the transmission principle of a gearbox provided in an embodiment of the present invention;

[0022] Description of reference numerals:

[0023] 1. Input shaft; 2. Intermediate shaft; 3. Planet carrier; B. Brake; C. Clutch; S1. Primary sun gear; S2. Secondary sun gear; P1. Primary planet gear; P2. Secondary planet gear; G1. Primary driving gear; G2. Primary driven gear; G3. Secondary driving gear; G4. Secondary driven gear. DETAILED DESCRIPTION

[0024] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0025] As an important component of mechanical transmission devices, reducers can be selected with different speed ratios according to their design requirements and usage scenarios. The speed ratio refers to the ratio of the speed of the driving shaft to the speed of the driven shaft. It has a significant impact on the transmission efficiency, load capacity, and other aspects of the mechanical system. When selecting a reducer, it is crucial to understand the differences in speed ratios and their impact on transmission performance. The choice of reducer speed ratio affects the transmission effect, load capacity, and transmission accuracy. A large speed ratio is suitable for heavy loads and high torque scenarios, while a small speed ratio is suitable for high speed and precision transmission. When selecting, consider working conditions, load requirements, transmission accuracy, and economy. The appropriate speed ratio can ensure the stability, reliability, and efficiency of the mechanical transmission.

[0026] When the speed ratio is large, the speed of the drive shaft decreases and the torque increases, which can provide greater torque output. It is suitable for scenarios that require a larger output torque and can ensure the reliability and stability of the transmission, such as heavy-load lifting machinery, construction machinery, etc.; when the speed ratio is small, the speed of the drive shaft increases and the torque decreases. It is suitable for scenarios that require a higher speed but do not require too much torque output, such as high-speed machine tools, fans, etc.

[0027] Select the appropriate speed ratio according to the size of the load required. The larger the load, the larger the speed ratio of the reducer needs to be selected to ensure the reliability and stability of the transmission. Electric loaders are suitable for ports, mining areas, steel, coal and other major fields, and are particularly suitable for the sand and gravel and concrete industries. They are engineering machinery with large loads. Currently, a small speed ratio gearbox with a low-speed motor is used to provide low-speed and high-torque working environments. The load-bearing capacity is low, the working efficiency is low, and the response speed is slow, which greatly increases the cost of using the whole machine. Therefore, the present application provides a large speed ratio gearbox that, in conjunction with a high-speed motor, can provide both low-speed and high-torque driving speeds and high-speed and low-torque driving speeds, thereby improving the operating efficiency and driving speed of the whole machine.

[0028] See also Figure 1 As shown, the gearbox provided by the present invention is now described. The gearbox includes an input shaft 1, a primary reduction planetary gear, a secondary reduction planetary gear, a brake B, and a secondary reduction transmission system. The input shaft 1 is connected to the main shaft of the drive motor, which directly drives the input shaft 1 to rotate or stop rotating. The primary reduction planetary gear is coaxially connected to the input shaft 1 and can directly drive the primary reduction planetary gear to rotate. The planet carrier 3 of the primary reduction planetary gear is engaged or disengaged with the input shaft 1 via a clutch C. The secondary reduction planetary gear is loosely mounted on the input shaft 1, and the secondary and primary reduction planetary gears share the planet carrier 3. The secondary reduction planetary gear transmits power through the primary reduction planetary gear. The brake B is fixed in the reducer housing and is used to control the braking of the planet carrier 3. The secondary reduction transmission system is engaged with the secondary reduction planetary gear. The power reduced by the secondary reduction transmission system is transmitted to the wheels via the drive axle. The transmission ratio i1 of the secondary reduction transmission system is ≥5.

[0029] The utility model provides a large-speed ratio gearbox, which adopts the cooperation of a two-stage planetary reduction and a two-stage reduction transmission system to obtain a larger driving speed ratio. The speed is reduced and the torque is increased during operation, which can provide a larger torque output and a higher load capacity, and can withstand a larger external load. It is suitable for working conditions that need to carry a large load, such as heavy-duty lifting machinery, engineering machinery, etc., and can ensure the reliability and stability of the transmission; when driving, it can provide high speed and low torque, and provide sufficient vehicle speed for the whole machine, thereby improving the operating efficiency and driving speed of the whole machine; the two reduction planetary gears share the planetary carrier 3, which is beneficial to saving space, reducing the size and weight of the gearbox, reducing the production cost, and also conducive to the miniaturization of the gearbox.

[0030] Because the gearbox is small in size and has a more flexible layout, the drive motor can make the whole machine have a higher driving speed and operating efficiency after passing through the reducer. The large speed ratio gearbox is adapted to the high-speed motor and can provide sufficient traction and vehicle speed for the whole machine.

[0031] The speed ratio refers to the gear ratio of the final reducer in a vehicle's drive axle. The transmission ratio i1 of the two-stage reduction transmission system in this application is ≥5. Currently, the speed ratio of short-ratio transmissions is between 2 and 3, so i1 is greater than that of short-ratio transmissions. The speed ratio or transmission ratio of this application can be achieved by adjusting the number of teeth on the mating gears in the two-stage reduction transmission system.

[0032] In some embodiments, see Figure 1 As shown, the primary reduction planetary gear set includes a primary sun gear S1 coaxially connected to the input shaft 1 and a primary planetary gear P1 mounted on the planetary carrier 3, with the primary planetary gear P1 meshing with the primary sun gear S1. The secondary reduction planetary gear set includes a secondary sun gear S2 loosely mounted on the input shaft 1 and a secondary planetary gear P2 mounted on the planetary carrier 3, with the secondary planetary gear P2 meshing with the secondary sun gear S2. The secondary reduction transmission system meshes with the secondary sun gear S2, and the secondary planetary gears P2 and the primary planetary gear P1 form a duplex gear. When the input shaft 1 drives the primary sun gear S1 to rotate, the primary sun gear S1 drives the primary planetary gear P1 to rotate. At this time, the secondary planetary gear P2 rotates synchronously with the primary planetary gear P1, and then drives the secondary sun gear S2 through the secondary planetary gear P2, thereby transmitting power to the secondary reduction transmission system.

[0033] In this embodiment, each planetary gear set does not need to be provided with a ring gear, which not only reduces the number of parts, but also further saves space, thereby reducing the size and weight of the reducer, and also reduces the processing cost. In particular, it makes the transmission structure simple and small in size, which facilitates the arrangement of the entire machine.

[0034] In this embodiment, the number of teeth of the first-stage sun gear S1 is n1, the number of teeth of the first-stage planetary gear P1 is n2, the number of teeth of the second-stage planetary gear P2 is n3, and the number of teeth of the second-stage sun gear S2 is n4; wherein, n2 ≥ n1, n4 > n2 > n3; in first gear, the speed is low and the torque is large. When the clutch C is disengaged and the brake B is engaged, the planet carrier 3 is restrained by the brake B and cannot rotate. The power transmission route is the input shaft 1, the first-stage sun gear S1, the first-stage planetary gear P1, the second-stage planetary gear P2, the second-stage sun gear S2, and finally the second-stage reduction transmission system. At this time, the speed ratio i2 of the two-stage reduction planetary gear is i2 = n2 / n1 × n4 / n3 > 1. After the power passes through the two-stage reduction planetary gear and the second-stage reduction transmission system, a larger speed ratio is obtained. At this time, a larger torque is provided for the working state of the entire vehicle, thereby improving the operating efficiency and performance of the entire vehicle. In second gear, the required speed is high and the torque is small, so that the whole vehicle can travel quickly and respond quickly. At this time, the clutch C is closed and the brake B is disconnected. The planetary carrier 3 is not constrained by the brake B. The power is transmitted to the planetary carrier 3 through the clutch C, and the two-stage reduction planetary gearbox is linked. At this time, the transmission ratio of the two-stage reduction planetary gearbox is i2=1, the output speed is high and the torque is small, which increases the speed of the whole vehicle.

[0035] In some embodiments, see Figure 1 As shown, the two-stage reduction transmission system includes a primary reduction gear set and a secondary reduction gear set. The primary reduction gear set is loosely mounted on the input shaft 1. The primary reduction gear set and the secondary reduction gear set are connected through an intermediate shaft 2. The secondary reduction gear set is connected to the drive axle.

[0036] In some embodiments, see Figure 1 As shown, the first-stage reduction gear set includes a first-stage driving gear G1 and a first-stage driven gear G2 that is meshed and connected. The first-stage driving gear G1 is loosely mounted on the input shaft 1 and is connected to the second-stage sun gear S2; the first-stage driven gear G2 is coaxially connected to the intermediate shaft 2.

[0037] In some embodiments, see Figure 1 As shown, the secondary sun gear S2 and the primary driving gear G1 are both connected to a hollow shaft, which is loosely sleeved on the input shaft 1. The secondary sun gear S2 and the primary driving gear G1 also form a duplex gear. This design simplifies the structure, reduces the volume, and facilitates the miniaturization of the reducer.

[0038] In some embodiments, see Figure 1 As shown, the secondary reduction gear set includes a secondary driving gear G3 and a secondary driven gear G4 that are meshed and connected. The secondary driving gear G3 is coaxially connected to the intermediate shaft 2, and the secondary driven gear G4 is connected to the drive axle.

[0039] In some embodiments, see Figure 1As shown, the transmission ratio i1 of the two-stage reduction transmission system is ≥10. Based on the above embodiments, the transmission ratio i1 of the two-stage reduction transmission system is calculated as follows: the number of teeth of the first-stage driving gear G1 is n5, the number of teeth of the first-stage driven gear G2 is n6, the number of teeth of the second-stage driving gear G3 is n7, and the number of teeth of the second-stage driven gear G4 is n8. Then i1 = n6 / n5 × n8 / n7. In order to obtain a larger transmission ratio, n5 < n6, n8 > n6 > n7. By selecting the appropriate number of teeth, i1 ≥ 5 can be achieved. By adjusting the number of teeth of each gear in the two-stage reduction transmission system, i1 can be made ≥ 10, obtaining a larger speed ratio, thereby improving the driving speed, working efficiency and response speed of the electric loader and shortening the single working cycle time. Among them, the first gear speed ratio i1 = n4 × n2 / n1 / n3 × n6 / n5; the second gear speed ratio i1 = 1 × n6 / n5, where 1 is the speed ratio i2 of the two-stage reduction planetary gear. For example, n1=19, n4=41, n2=43, n3=17, then the speed ratio of the two-stage reduction planetary gearbox is i2=41×43 / 19 / 17=5.458, and the number of teeth of G2 and G1 can be arbitrarily set according to the required speed ratio.

[0040] In some embodiments, see Figure 1 As shown, the outer hub of the clutch C is connected to the planetary carrier 3 , and the inner hub of the clutch C is connected to the input shaft 1 .

[0041] like Figure 1 As shown, the working principle of the high speed ratio gearbox provided by the utility model is as follows:

[0042] The drive motor power input is directly connected to the first-stage sun gear S1. In first gear, the entire machine is in working condition, requiring low speed and high torque. At this time, the clutch C is disengaged, the brake B is engaged, and the shared planetary carrier 3 is braked. The power is output to the first-stage driving gear G1 through the input shaft 1, the first-stage sun gear S1, the first-stage planetary gear P1, the second-stage planetary gear P2, and the second-stage sun gear S2. After being reduced by the first-stage driven gear G2, the second-stage driving gear G3 and the second-stage driven gear G4, it is output to the wheels. At this time, the gearbox speed ratio is large (the speed ratio is above 10); in second gear, the entire vehicle is in driving condition, requiring high speed, low torque and high driving speed. At this time, the clutch C is engaged, the brake B is disengaged, and the brake of the planetary carrier 3 is released. The clutch C links the planetary carrier 3 and the sun gear. At this time, the planetary carrier 3, the first-stage sun gear S1, the second-stage sun gear S2 and the planetary gears at all levels are linked. The speed ratio of the two-stage reduction planetary gear is 1. The power is transmitted from the two-stage reduction planetary gear to the first-stage driving gear G1 and is transmitted to the wheels on both sides through the secondary reduction transmission system.

[0043] From the above working principle, it can be seen that the high-speed ratio gearbox is adapted to the high-speed motor, which can provide sufficient traction and speed for the entire machine, thereby improving the working efficiency of the entire machine. At the same time, the gearbox provided by this application can be reduced in size and weight, with a small external volume and small space occupation, and is more flexible in the layout of the entire machine.

[0044] At the same time, if a large speed ratio is not required based on the matching results of the overall traction force and vehicle speed, it is only necessary to cancel the intermediate shaft 2 and the first-level driven gear G2 and the second-level driving gear G3 connected to the intermediate shaft 2. The power transmission route is changed from the first-level sun gear S1, the second-level sun gear S2, the first-level driving gear G1, the first-level driven gear G2, the second-level driving gear G3, and the second-level driven gear G4 to the first-level sun gear S1, the second-level sun gear S2, the first-level driving gear G1, and the second-level driven gear G4. The solution is flexible and convenient.

[0045] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant description of other embodiments.

[0046] Based on the same inventive concept, an embodiment of the present application also provides an electric loader, including a high-speed motor and the above-mentioned gearbox.

[0047] Based on the same inventive concept, the embodiments of the present application can also be applied to heavy-duty lifting machinery, engineering machinery and mining machinery, including the gearbox and a high-speed motor driving the gearbox.

[0048] The electric loader and construction machinery provided in this application utilize a high-speed motor to drive a high-speed ratio gearbox. Because high-speed motors enable the entire machine to achieve higher travel speeds and operating efficiency compared to existing low-speed motors, the high-speed ratio gearbox, when adapted to the high-speed motor, can provide sufficient traction and speed for the entire machine, thereby improving the overall operating efficiency of the entire machine. Furthermore, because high-speed motors are smaller than low-speed motors, the gearbox provided in this application is also smaller, allowing for greater flexibility in overall machine layout and reducing overall machine manufacturing costs.

[0049] The explanation of high-speed motors and low-speed motors is as follows:

[0050] High-speed motors are motors with speeds exceeding 3000 rpm. They are capable of operating at high speeds and high loads. Their key characteristic is their high speed but low torque, making them suitable for high-speed applications. High-speed motors are widely used in applications such as high-speed compressors, high-speed cutting machines, high-speed pneumatic tools, and high-speed transportation equipment.

[0051] Low-speed motors, which operate at speeds below 3000 rpm, are capable of operating at low speeds and high torque. Their key characteristic is their slow speed combined with high torque, making them suitable for applications requiring low speeds and high torque. Low-speed motors are widely used in industries such as steel manufacturing, mining machinery, water pumps, and fans.

[0052] The main difference between a high-speed motor and a low-speed motor lies in the speed and torque. A high-speed motor has a fast speed but a small torque, and is suitable for high-speed operation; a low-speed motor has a slow speed but a large torque, and is suitable for low-speed and high-torque situations. When selecting a motor, it is necessary to select the appropriate speed and torque according to different application scenarios. Therefore, generally speaking, for electric loaders and construction machinery, a small speed ratio transmission matched with a low-speed motor is selected. However, the present application improves the speed ratio of the transmission by designing a two-stage reduction planetary gearbox and a two-stage reduction transmission system, and is used in conjunction with a high-speed motor. It can be used in high-torque and low-speed working situations, as well as high-speed and low-torque driving situations, and can therefore improve the operating efficiency, carrying capacity and driving speed of the entire machine as needed.

[0053] To explain, an electric loader is a type of loader that uses a power battery or grid electricity as an energy source to provide power to the entire machine to drive the entire machine. It is suitable for various fields such as ports, mining areas, steel, and coal, and is particularly suitable for the sandstone and concrete industries. The axle of an electric loader consists of a front axle with a drive motor and a gearbox, and a rear axle with a drive motor and a gearbox. The gearbox is a mechanism used to change the speed and torque from the engine. It can fix or change the transmission ratio of the output shaft and input shaft, and is one of the core transmission components of the electric loader.

[0054] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A gearbox, characterized in that: include: Input shaft (1); A first-stage reduction planetary gear is coaxially connected to the input shaft (1), and a planet carrier (3) of the first-stage reduction planetary gear is engaged with or disconnected from the input shaft (1) via a clutch (C); A secondary reduction planetary gear is hollowly mounted on the input shaft (1), and the secondary reduction planetary gear and the primary reduction planetary gear share the planet carrier (3); A brake (B), used for controlling the braking of the planet carrier (3); as well as A two-stage reduction transmission system meshing with the two-stage reduction planetary gear; The power decelerated by the secondary reduction transmission system is transmitted to the wheels via the drive axle; The transmission ratio i1 of the two-stage reduction transmission system is ≥5.

2. The gearbox according to claim 1, characterized in that: The first-stage reduction planetary gear comprises a first-stage sun gear (S1) coaxially connected to the input shaft (1) and a first-stage planetary gear (P1) mounted on the planetary carrier (3), and the first-stage planetary gear (P1) is meshed with the first-stage sun gear (S1); the second-stage reduction planetary gear comprises a second-stage sun gear (S2) loosely mounted on the input shaft (1) and a second-stage planetary gear (P2) mounted on the planetary carrier (3), and the second-stage planetary gear (P2) is meshed with the second-stage sun gear (S2); the second-stage reduction transmission system is meshed with the second-stage sun gear (S2); the second-stage planetary gear (P2) and the first-stage planetary gear (P1) form a double gear.

3. The gearbox according to claim 2, characterized in that: The two-stage reduction transmission system comprises a primary reduction gear set and a secondary reduction gear set, wherein the primary reduction gear set is loosely mounted on the input shaft (1), the primary reduction gear set and the secondary reduction gear set are connected via an intermediate shaft (2), and the secondary reduction gear set is connected to the drive axle.

4. The gearbox according to claim 3, characterized in that: The primary reduction gear set comprises a primary driving gear (G1) and a primary driven gear (G2) meshingly connected thereto; the primary driving gear (G1) is loosely sleeved on the input shaft (1); the primary driving gear (G1) is connected to the secondary sun gear (S2); and the primary driven gear (G2) is coaxially connected to the intermediate shaft (2).

5. The gearbox according to claim 4, characterized in that: The secondary sun gear (S2) and the primary driving gear (G1) are both connected to a hollow shaft, and the hollow shaft is loosely sleeved on the input shaft (1).

6. The gearbox according to claim 4, characterized in that: The secondary reduction gear set comprises a secondary driving gear (G3) and a secondary driven gear (G4) meshingly connected thereto; the secondary driving gear (G3) is coaxially connected to the intermediate shaft (2), and the secondary driven gear (G4) is connected to the drive axle.

7. The gearbox according to claim 6, characterized in that: The transmission ratio i1 of the two-stage reduction transmission system is ≥10.

8. The gearbox according to claim 7, characterized in that: The number of teeth of the primary driving gear (G1) is n5, the number of teeth of the primary driven gear (G2) is n6, the number of teeth of the secondary driving gear (G3) is n7, and the number of teeth of the secondary driven gear (G4) is n8, wherein n5<n6, n8>n6>n7.

9. The gearbox according to claim 1, characterized in that: The outer hub of the clutch (C) is connected to the planetary carrier (3), and the inner hub of the clutch (C) is connected to the input shaft (1).

10. An electric loader, characterized in that: It comprises a gearbox as described in any one of claims 1 to 9 and a high-speed motor driving the gearbox.

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