Introduction of automobile drive shaft and drive axle
发布时间：2016.11.15 新闻来源：邢台远拓汽车零部件制造有限公司
The transmission shaft and drive axle of automobile are introduced
1 、 drive shaft
The role of the transmission shaft is self-evident. This article focuses on the universal transmission (Cardan drive) on the transmission shaft.
In a front engine rear drive (or all wheel drive) car suspension vehicle, due to deformation in the process of movement, drive axle main reducer input shaft and the transmission (or transfer) often have the relative motion of the output shaft, in addition, to effectively avoid certain mechanism or device (can not achieve linear transfer), there must be a device to realize the normal transmission of power, so there is a universal joint drive. Universal joint drive must have the following characteristics:
A ensures that the relative position of the two shafts to be connected can reliably transmit power when the range of prediction is changed;
B ensure that the two shafts connected can operate evenly. The additional load, vibration and noise due to the angle of the cardan joint shall be within the allowable range;
C, high transmission efficiency, long service life, simple structure, easy manufacture and easy maintenance.
On the car, because the output of a cross axle universal joint shaft relative to the input shaft (a certain angle) is not constant rotation, so we must adopt double universal joint (or joint) and the drive shaft is connected with the transmission of the two yokes are arranged in the same plane, and the twenty thousand from the angle equal section. This is very important. The angle of the cardan joint shall be minimized when designing.
The unbalance of the drive shaft assembly is the main cause of the bending vibration of the transmission system. The vibration and noise caused by it are obvious. In addition, the axial cardan shaft of the transmission shaft, sliding spline clearance, the drive shaft assembly at two ends of the centering precision, high-speed rotary thermal effect of elastic deformation and the transmission of the transmission shaft on the spot when the balance factors can change the transmission shaft assembly unbalance. Reducing the unbalance of the transmission shaft is extremely important for automobiles, especially for high speed cars, such as cars, which can cause a lot of related faults or abnormal damage.
2, drive axle
The drive axle is one of the main assemblies in the automobile transmission system. Its main role is to ensure that when the transmission in the most high-end, the maximum speed enough traction to overcome the driving resistance and get the car on a good road conditions, of course, is a prerequisite to select the appropriate gear ratio. In addition, the drive axle has the function of bearing loads.
2.1 type of drive axle
A, open type drive axle
The utility model is characterized in that the main reducer and the differential are installed in the axle housing, the axle housing is fixed on the frame or the vehicle body, and the wheel is driven by a universal joint drive shaft. This type of drive bridge greatly increases the clearance from the ground, reduces the non load quality (with the independent suspension structure), improves the ride comfort of the vehicle and improves the ability of skid resistance. But its manufacturing cost is high, the structure is complex, usually use in the car or on the special vehicle.
B and non disconnecting drive axle
The use of non broken drive axle, corresponding to the use of non independent suspension. This is commonly used on trucks. Since it is equivalent to a rigid beam, the entire mass of the shaft is part of a non sprung mass. Therefore, the car's ride comfort, handling stability and pass are better than the open drive bridge. But its application is very extensive, the most important feature is its simple structure, good manufacturing process, low cost, reliable, durable and convenient maintenance. With the continuous progress of manufacturing and process technology, many deficiencies have been greatly improved.
2.2 main reducer
The main reducer is the key component of the drive axle. According to the requirements of the drive, there are single stage reducer, double stage reducer, double speed reducer and single-stage reducer, plus wheel reducer.
Single stage reducer, double stage reducer, double speed reducer, single stage reducer and wheel side reducer have the advantages of simple and light weight (only a pair of bevel gears) and widely used. Most of the driving axle of Dongfeng Motor adopt this structure. The first stage consists of a cone gear pair and second bevel gear pair or the first gear pair and second conical gears, can obtain a large transmission ratio, reduce the bridge shell size, increased ground clearance can be obtained by different combinations of two kinds of gear transmission ratio, in good road use small drive the large transmission ratio, in bad pavement, traction is big, easy to start to get bigger and bigger reduction ratio of the ground clearance and the defect ratio is not too large, otherwise the driven bevel gear size is too large, the ground clearance effect of driving axle, the poor. The utility model has the advantages of large weight and higher manufacturing cost than a single stage reducer. The control device is added, and the quality of non overloading is also increased. Not only are designs more difficult, but manufacturing and maintenance are more complex. They are often used on off-road vehicles and heavy duty dump trucks.
2.3 differential
In the process of vehicle movement, many factors will lead to the difference of the distance between the left and right wheels, such as cornering, uneven tire pressure, uneven left and right loads, different road surfaces, etc.. If there is no mechanism, it will cause accelerated wear and tear of the tire and consume power. To this end, differential (wheel differential) must be added. Also, in the multi axis drive, between the front and rear drive axle, rear axle or in between will speed difference, or interference caused by tire wear, this should also set the differential (inter axle differential).
The differential is made up of four planetary gears, 2.5 axis gears, a cross shaft and a differential case, which are left with the planetary gears
