Gearbox Working Principle and Maintenance Method

Gearbox working principle and maintenance method

The gearbox is an important part of the car. What is the working principle of the gearbox? How to maintain the gearbox? Let's take a look at the working principle and maintenance method of the gearbox.

How the gearbox works

The manual transmission consists mainly of gears and shafts, which produce variable speed torque through different gear combinations. The automatic transmission AT is composed of a hydraulic torque converter, planetary gears and hydraulic control system, through hydraulic transmission and gear combination. To achieve the variable speed torque.

Among them, the hydraulic torque converter is the most characteristic component of AT. It consists of components such as pump wheel, turbine and guide wheel, and directly inputs the engine power transmission torque and separation. The pump wheel and the turbine are a pair of working combinations. They are like two fans placed opposite each other. The wind blown by one active fan will drive the blades of the other passive fan to rotate. The flowing air—the wind becomes the medium of kinetic energy transmission. . If liquid is used instead of air as the medium for transmitting kinetic energy, the pump wheel will rotate the turbine through the liquid, and then a guide wheel is added between the pump wheel and the turbine to improve the efficiency of liquid transfer. Since the range of the automatic torque converter of the torque converter is not large enough and the efficiency is low, several rows of planetary gears are connected in series behind the turbine to improve the efficiency, and the hydraulic control system automatically manipulates the planetary gears according to the change of the engine operation, thereby realizing automatic shifting.

Gearbox working principle and maintenance method

Gearbox maintenance method

1. Master the cycle of replacing the automatic transmission oil. The internal control mechanism of the automatic transmission is very precise and the clearance is small. Therefore, most manufacturers recommend that the automatic transmission change cycle is generally two years or 40,000-60,000 km. In the normal use process, the operating temperature of the transmission oil is generally around 120 degrees Celsius, so the quality of the oil is very high and must be kept clean. Secondly, after the transmission oil has been used for a long time, it will produce oil stains, which may form sludge, which will increase the wear of the friction plates and various components, and also affect the system oil pressure, which will affect the power transmission. Third, the sludge in the dirty oil will cause the movement of the valve body in each valve body to be unsatisfactory, and the oil pressure control is affected, thereby causing an abnormality in the automatic transmission.

2. Always check if the oil level of the automatic transmission is normal. The automatic transmission oil inspection method is different from the engine oil. The engine oil is checked in the cold state, and the transmission oil needs to preheat the oil to about 50 °C, and then the gear lever stays in each gear for 2 seconds. After being placed in the parking gear, the normal oil level of the dipstick should be between the highest and lowest lines. If it is not enough, the same quality oil should be added in time.

3. Replace the transmission oil properly. At present, the better oil change method is dynamic oil change. The special gearbox cleaning equipment is used. During the operation of the gearbox, the old oil is fully circulated, and the new gearbox oil is added after the discharge, so that the oil change rate is obtained. Up to 90 or more, to ensure a good oil change.

Gearbox maintenance misunderstanding

Misunderstanding 1: Deterioration

The automatic transmission oil replacement cycle is based on the number of kilometers traveled or the time of use. If the vehicle manual is not specified, it will be replaced according to the mileage of 60,000-80,000 kilometers.

Misunderstanding 2: no need to change oil

Many car owners did not develop the awareness of replacing the automatic transmission oil. The replacement of inferior oil and the failure to change the oil according to the model will also cause the automatic transmission to be "short-lived".

Misunderstanding 3: Two oil change methods

"Hand change" is convenient and time-consuming. The disadvantage is that the oil change is not complete. Only one-quarter to one-third of the old oil can be discharged, which is about 4 liters.

The "machine change" process takes about 1 hour and requires about 12 liters of oil. The advantage of this oil change method is that the oil change is more thorough and can discharge more than 85% of the old oil.

It is worth noting that both oil exchange methods are carried out with the engine starting. Replace the automatic transmission fluid. It must be in the state of hot car during operation. It should be driven for more than 20 minutes before replacement. When changing the oil, start the engine, and move the gears from the P block to the N, D, L1, L2 and other gears, and then start to change the oil.