The central differential lock locks the central differential, so that the front and rear drive axles are rigidly connected and most of the torque is transmitted to the anti-skid drive axle; The rear differential lock locks the rear differential, and the two rear wheels are synchronized when opened. When a single rear wheel slips, most of the torque of the rear drive axle can be transferred to the non-slip rear wheel. The principle of front differential lock and rear differential lock is the same. Differential lock is used to help vehicles cope with bad road conditions and get out of trouble.
Different differentials adopt different locking methods. At present, the common differential locks have the following locking methods: forced locking, high-friction self-locking, tooth-embedded, torsion and viscous coupling. Among them, the jaw is often used in medium and heavy trucks, so I won't elaborate here.
Forced locking type
The forced locking differential lock is to set a differential lock on the ordinary symmetrical bevel gear differential. This differential lock has the advantages of simple structure, easy manufacture and high torque distribution ratio. However, the operation is quite inconvenient, and it is generally necessary to stop; In addition, if the differential lock is connected too early or taken off too late, a series of problems will occur without the differential, and the torque distribution cannot be changed.
High friction self-locking type
High friction self-locking type has friction plate type and slider cam type. Friction plate type locks the differential through the friction torque generated by the relative sliding of friction plates. This kind of differential lock is simple in structure and works smoothly, and it is most common in cars and light vehicles. The slider cam type locks the differential by using the larger friction torque between the slider and the cam, which can greatly improve the passing performance of the automobile, but it has complex structure, high processing requirements, large wear of friction parts and high cost. The above two kinds of high-friction self-locking differential locks can distribute the output torque of the left and right wheels within a certain range, and the engagement and disengagement are automatic, so they are widely used.
Sen style
Torsten differential is a new type of inter-axle differential, which is widely used in all-wheel drive vehicles (such as Audi TT). ? Tolson? This name is a registered trademark of Gleason Company. Torque sensitive differential? . It adopts the basic principle that worm gear and worm drive have self-locking characteristics. Torsten differential has compact structure, wide and adjustable transmission torque range, and is widely used in the center differential of all-wheel drive vehicle and the inter-wheel differential of rear drive axle. However, due to its automatic locking function at high speed and torque difference, it can not be used in the inter-wheel differential of the front drive axle.
Viscous coupling type
Some four-wheel drive cars use viscous couplings as differentials. This new differential uses silicone oil as the medium to transmit torque. Silicone oil has a high coefficient of thermal expansion. When the speed difference between the two shafts is too large, the temperature of silicone oil rises sharply and its volume expands continuously, and silicone oil pushes the friction blades to be closely combined. At this time, the transmission shafts at both ends of the viscous coupling are directly connected into a whole, that is, the viscous coupling is locked. This phenomenon is called. Hump phenomenon? . This phenomenon happens very quickly, the differential suddenly locks up, and the vehicle can easily leave the anchorage. Once the stirring is stopped, the temperature of the silicone oil will gradually drop, and the hump phenomenon will disappear until it is completely cooled. In view of the soft and steady torque transmission and fast differential response of viscous coupling, the performance of all-wheel drive vehicle is greatly improved when it is applied to the inter-axle differential system of driving axle as an inter-axle differential.