【 Classic case 】 Improper rescue gearbox damaged case analysis

【 Classic case 】 Rescue of damage of gearbox caused 2019 - case analysis 06 - 21 a, case introduction SCANIA SCANIA G480 tractor, is a high-end heavy card, 'the king of the road. The gearbox consists of two parts, main gearbox, the front is with automatic clutch, electric fork 'manual gear main gearbox, the back is with the planetary gear transmission. A total of 12 forward gears, two reverse gear. Such models are often due to improper rescue gearbox internal damage, in the process of rescue and fee should be prompt rational, pay attention to the reasonable confirmation fee. Mark SCANIA SCANIA G480 tractor in high speed collision fence be or get out of danger, cause the front vehicle, on the right side of the tire, such as damaged tank. Fee when found within the main gearbox spindle, 9 plate bearing, six wheel inner hole and synchronizer ablation is damaged, but the transmission housing condition, no oil trace. View the damage, judge the gearbox internal loss is due to the lack of oil condition caused by high speed rotation for a long time. The destruction of the oil film friction pair, and appear the phenomenon of 'iron sharpens iron, hot metal. ChengXiu factory think automatic braking systems, transmission damage happened after the accident, transmission oil also does not have the trace of water, to repay transmission assembly, 14. 50000 yuan. Two, the analysis process through the analysis of the underlying car for half a tractor trailers, length of more than 10 meters, rear wheel drive, there is no clutch pedal, gearbox for 'automatic transmission in the broadest sense of the term. After insurance accident happens, the front wheel tires and fuel tank damage, to rescue them. Could rescue companies use trailer rescue, lift the two wheels, using the trailer only at the back of the drive wheel on the ground, not dismantle the shaft or half shaft, trailer gearbox damage after the rescue. The gearbox to work properly, the transmission shaft and gear high-speed rotation, can stir up the transmission oil, provide sufficient lubrication to the transmission. But when the vehicles in the towing line, if idling, still drive train connection, only the gears in the gearbox spindle rotating at high speed, the intermediate shaft gear and shaft gear does not rotate, oil in the gearbox to throw up, inadequate lubrication, high temperature cause serious damage. Rescue when the rear wheel rotation, through the drive shaft, etc. , keep the power input gearbox main shaft. Fittings such as spindle bearing and gear on the inner hole, for getting the gear oil up to the surface of the friction pair, cause damage. Accident vehicle front wheel is lifted at the same time, the transmission fluid flow backwards, the former after much, less set in front of the main shaft bearing damage is more serious, set in the main shaft damage at the back of the part is lighter. Finally, after communication with ChengXiu factory again and again, the gearbox accessories to give out, successful loss 140000 yuan. Three, experience sharing, rescue vehicles, equipped with automatic transmission of heavy vehicles, was tractor driving wheel touchdown, be sure to remove the drive shaft or half shaft, cut off the input power relay route of transmission, so as to avoid transmission is damaged. Equipped with automatic transmission four-wheel-drive cars, etc. , can back to the best of back. Two drive cars equipped with automatic transmission, driving wheel off the ground. Gearbox so as to ensure no additional power input, to protect the transmission of internal components will not damaged. （ Public lovers)