Concept and Application Advantages of Continuously Variable Speed Tractors

Tractors are one of the important equipment in agricultural machinery, and the tractor transmission system is the core component of tractor performance, which determines the transmission efficiency and handling performance of the entire machine. Tractor transmission systems can be divided into two types based on their implementation form and number of gears: stepless transmission and stepless transmission. Among them:
1. Stepped transmission: includes two technologies: mechanical shifting and power shifting; According to the difficulty level of power shifting technology, it can be divided into: power Hi Lo/power shuttle, multi speed power shifting, and full power shifting.

2. Continuously Variable Transmission: It includes three technologies: HST (Hydraulic Continuously Variable Transmission), V-belt Mechanical Continuously Variable Transmission, and CVT (Hydraulic Mechanical Hybrid Continuously Variable Transmission). Due to its low transmission efficiency and high noise, HST technology can only be used on tractors below 70 horsepower; The mechanical continuously variable transmission of V-belt relies on friction to transmit torque, with weak overload resistance and poor adaptability to working conditions; CVT combines the technology of hydrostatic transmission and mechanical transmission, retaining the characteristic of stepless regulation of hydrostatic pressure, while also using mechanical transmission to solve the problem of low efficiency, thus becoming the mainstream technical route for CVT tractors worldwide.

In terms of advantages, the core technical feature of CVT tractors is the continuously adjustable speed, which is particularly advantageous for the matching application of tractors in the field. When high-power tractors work in the field (such as plowing deep, loosening deep, and high-performance sowing), modern tractors increase the number of transmission gears in the field to fully utilize engine power, and the transmission ratio between gears is also relatively close. However, the speed difference between adjacent gears is still around 1 km/h, which still cannot accurately match the working load. At the same time, the impact feeling during shifting is obvious, Therefore, CVT becomes the ideal transmission choice. The more precise and efficient power output gives it an irreplaceable unique advantage.
（1） Advantages of application scenarios for increasing grain production
1. When the tractor is engaged in deep plowing operations, if it passes through sloping land, the resistance will increase significantly, but CVT can smoothly and automatically slow down and pass quickly; Mechanical shift tractors with the same power require frequent shifting, resulting in significant speed changes and reduced productivity; In addition, when the tractor is plowing, due to different soil specific resistance, conventional tractors often experience insufficient engine power when working in high gear, while lowering the load by one gear is too light. CVT tractors can be set at any speed, which fully utilizes engine power and increases the efficiency of plowing operations. At this time, the advantage of continuously variable transmission is very prominent.

2. During sowing or bundling operations, the tractor's power output requires a constant output speed, and the walking speed must be able to change at any time according to the soil resistance and grass density to ensure high sowing quality and productivity; The CVT tractor can fully meet this requirement. So the advantages of CVT in bundling and sowing operations are also very obvious.

The CVT continuously variable speed tractor product is well matched with large agricultural machinery such as hydraulic flip plows, high-performance seeders, power driven rakes, large bundling machines, and deep loosening combined land levelers. The product has a wide range of application scenarios and good adaptability, providing an intelligent agricultural machinery foundation for improving grain yield.
（2） Fuel economy advantages
Compared to power shift and mechanical shift, a major advantage of CVT transmission is that it can perfectly match the engine characteristic curve, allowing the engine to work in the optimal area all the time. Although the power shift gearbox can match the engine's power characteristic curve as much as possible through fine control and calibration, it cannot achieve the same level as the CVT gearbox. By continuously adjustable transmission, the engine can always be in an efficient working zone, thereby achieving better fuel efficiency.
（3） Driving handling and comfort advantages
The CVT continuously variable transmission can better adapt to various operating speed requirements, and the use of hydrostatic pressure can achieve comfortable vehicle starting. At the same time, thanks to the exquisite structural design and fine parameter tuning, the hydraulic section shifts smoothly to the mechanical section, with almost no noticeable gear changes, improving driving comfort. In addition, combined with the cruise speed control handle, the driver only needs to push and pull the handle to achieve acceleration and deceleration of the vehicle when controlling the speed, which is convenient to operate and reduces driving fatigue.