When judging the power performance of a vehicle, the first thing to look at is the engine, gearbox and axle, which are often called the “three major parts”. It is these three parts that together make up the power chain of the truck. To solve the problem of axles, you must first understand what axles are. The explanation given by Baidu Encyclopedia is: “Axles are also called axles. They are connected to the frame through suspension, and wheels are installed at both ends. They are mainly used to bear the load of the car and maintain the normal driving of the car on the road.”This statement may be too general, but the description is indeed more intuitive. In addition to carrying the load of the truck, it also transmits the traction or braking force of the wheels and the lateral force through the suspension to the frame. In other words, it transmits the forces in all directions between the frame or load-bearing body and the wheels and the bending moment and torque generated by them.
Classification of Axles
There are many types of axles. According to their different uses, axles can be divided into four types: steering axles, driving axles, steering driving axles and supporting axles. Among them, they can be divided into driving axles and driven axles according to whether there is power output.
Steering axles and supporting axles are both driven axles, which means they are driven to rotate. Generally, trucks use rear-wheel drive, so the front axle is mostly a steering axle, and the rear axle or the middle and rear axles are driving axles.
Steering Axle
The steering axle, as its name suggests, uses the steering knuckle to deflect the wheel, thereby realizing the steering of the car. In addition, it also needs to bear the vertical load between the wheel and the frame and the longitudinal road resistance. The steering axle is mainly composed of: bridge, kingpin, steering knuckle, wheel hub, brake, generally a traditional reverse-bend I-beam, with a relatively simple manufacturing process. There is a fist-shaped part at each end with a through hole, which is connected to the left and right steering knuckles through the kingpin, and the kingpin is fixed in the front axle hole with a threaded wedge lock pin, so that it cannot rotate relative to the front axle.
When the car turns, the steering rocker arm swings in the longitudinal plane, and the steering straight tie rod, steering knuckle arm, left trapezoidal arm, steering tie rod and right trapezoidal arm are used to manipulate the front wheels of the car to turn a certain angle, thereby changing the direction of the car.
Drive Axle
Generally speaking, the rear axle of a truck is a drive axle, which mainly carries the load of the rear part of the truck, and needs to complete the power transmission between the transmission shaft and the gearbox, reduce the power output of the engine and increase the torque, and then change the transmission direction. The main reducer and half-axle are output to the wheels. The composition of the drive axle is relatively complex. It is located at the end of the transmission system and is mainly composed of the main reducer, differential, wheel transmission device and drive axle housing.
Moreover, it should be noted that there are many types of drive axles, including drive axles, steering drive axles and electric drive axles. Among them, the steering drive axle has a steering function, while the electric drive axle is a relatively new thing. It integrates the motor and reducer on the axle, so it can reduce the components of the whole vehicle, reduce the total weight of the vehicle and improve the transportation efficiency.
Support Axle
The support axle is relatively simple. It has neither driving function nor steering. It only needs to bear the vertical load of the truck, as well as the longitudinal force and lateral force and the torque caused by these forces. For a three-axle vehicle with a single axle drive, the rear axle is generally set as a support axle. Of course, the axles on the trailer are all supporting axles.
As one of the “three major parts” of a truck, the axle is a very important component. It not only bears the entire weight of the truck, but is also responsible for vehicle steering, driving, braking and other functions.
