The traditional traveling device of construction machinery adopts mechanical transmission or hydro mechanical transmission. Mechanical transmission has the advantages of high transmission efficiency and high transmission precision. But it is inconvenient to shift gears and adjust speed, so it is difficult to realize intelligent control. The hydraulic mechanical transmission mode introduces the hydraulic torque converter on the basis of the mechanical transmission mode. The hydraulic torque converter has the advantages of adaptive transmission ratio and load, soft transmission, etc. However, the high efficiency area of the hydraulic torque converter is very narrow, and the low-speed stability is poor. For construction machinery with low driving speed and requiring frequent starting, braking and reversing, the total transmission efficiency is low, resulting in large heating of the system, poor operability and high labor intensity of the driver.
Hydrostatic transmission has the advantages of good micro motion, high speed stiffness, high transmission efficiency, easy starting, braking and reversing, and easy to realize electro-hydraulic compound control. In recent years, with the development of hydraulic industry, the reliability of hydraulic components has been continuously improved and the cost has been continuously reduced. At present, the transmission modes of the traveling drive system of construction machinery include mechanical transmission, hydro mechanical transmission, hydraulic transmission and motor drive. Each transmission mode has its own advantages and disadvantages. This article will introduce mechanical transmission and its advantages and disadvantages.
Mechanical transmission refers to the transmission mode in which the power of the engine finally drives the wheels through the clutch, gearbox, universal joint, transmission shaft, drive axle and wheel reducer to make the construction machinery run. Because it only needs to overcome the friction resistance of the motion range, its speed loss is very small. Therefore, the utility model has the advantages of high transmission efficiency, high transmission precision, reliable transmission, etc. However, the speed adjustment mainly depends on the gear shifting of the gearbox. The speed regulation inertia is very large and the response speed is not high. If the driver operates the gearbox to shift, the new technology of hydraulic control of construction machinery is difficult to master the best shift time, and increases the labor intensity of the driver. If the intelligent shift transmission is adopted, the cost will be greatly increased. Due to the above shortcomings, at present, the construction machinery seldom adopts the simple mechanical transmission mode.
