What is the role of the half shaft What are the types of support

The function of the half-shaft is to transfer the torque from the differential to the wheels and propel the car forward.

The half-shaft support form used by modern automobiles is commonly used in two types: fully floating and semi-floating, and the full floating type is the most widely used.

The inner end of the full floating half shaft is inserted into the splined hole of the half shaft gear, and the outer end is connected with the wheel Yi, and the bearing that supports the half shaft is installed between the wheel load and the axle housing, and the vehicle load of this support form is all borne by the axle housing, and the half shaft is only used to drive the wheel, only bears the torque, and does not bear the bending moment.

Semi-floating structure is widely used in cars, the bearing of the half shaft is installed between the half shaft and the axle housing, the wheel is directly fixed on the half shaft, the vehicle load and the lateral load when turning all act on the half shaft, and the outer end bears all the bending torsion.

Half shafts are also called drive axles.

The half-shaft is a solid shaft that transmits torque between the differential and the driving wheel, and its inner end is generally connected with the half-shaft gear through splines, and the outer end is connected with the hub.

The half-shaft commonly used in modern automobiles has two types: fully floating and semi-floating according to their different support types.

The fully floating half shaft only transmits torque and does not bear any reaction force and bending moment, so it is widely used in all kinds of automobiles. The fully floating half shaft is easy to disassemble and remove, and the half shaft can be removed by simply unscrewing the bolts on the half axle flange, while the wheels and axle housing can still support the car, thus bringing convenience to the car maintenance.

The semi-floating half-shaft transmits torque and absorbs all reaction forces and bending moments. Its simple supporting structure and low cost make it widely used in all kinds of cars with small reaction moments. However, this kind of half-axle support is troublesome to dismantle, and if the half-shaft is broken during the car driving, it is easy to cause the danger of the wheel flying off.

The fully supported crankshaft of the V-shaped engine can be divided into full-supported slag-bearing crankshafts and non-fully-supported crankshafts according to the support mode of the crankshaft

1. Fully supported crankshaft is called fully supported crankshaft. The total number of main journals (including the main journals at the front and rear ends of the crankshaft) is one more than the number of cylinders in the fully supported crankshaft of an in-line engine, and the crankshaft is not fully supported. In the adjacent two twists asked.

Diesel engines mostly use fully supported crankshafts, and the total number of main journals is one more than half of the number of cylinders. The advantage of a fully supported crankshaft is that it increases the stiffness of the crankshaft and reduces the load on the main bearing.

2. Its disadvantage is that the number of main bearings of the crankshaft is large, and the size of the body is long. In the adjacent two cranks, a main journal is nailed to the crankshaft.

According to the support mode of the crankshaft, the crankshaft can be divided into two types: fully supported crankshaft and non-fully supported crankshaft.

1. Be cautious of fully supported crankshafts. At the intersection of the two adjacent cranks, the crankshaft with a main journal nailed is called a fully supported crankshaft. The total number of main journals of the fully supported crankshaft of the in-line engine is more than the number of cylinders; The V-shaped engine has a fully supported crankshaft, and the total number of main journals is one more than half of the number of cylinders.

The advantage of a fully supported crankshaft is that it increases the stiffness of the crankshaft and reduces the load on the main bearing. Its disadvantage is that the number of main bearings of the crankshaft is large, and the size of the body is long. Diesel engines mostly use fully supported crankshafts.

2. Non-fully supported crankshaft. In the case of two adjacent crankshafts, the crankshaft without one main journal is connected, it is called a non-fully supported crankshaft.

The function of the half-shaft bridge bearing is to attenuate the vibration, protect the half-shaft and other components, the half-shaft (drive shaft) is subject to torsion, shear, tension and compression, impact and other alternating stresses, and may also cause the torsion and bending vibration of the drive shaft, resulting in additional stress, uneven stress distribution, and sliding friction between the drive journal and the bearing.

Bridge bearings are arranged on the half shaft to attenuate vibration and protect the half shaft and other components.

The alternating stress of the half-shaft (drive shaft) such as torsion, shear, tension and compression, impact can also cause torsion and bending vibration of the drive shaft, resulting in additional stress; uneven stress distribution; There is sliding friction between the drive journal and the bearing.

The shaft that transmits torque between the half-shaft gearbox reducer and the drive wheel (in the past, it was mostly solid, but because the hollow shaft rotation unbalance control is easier, therefore, many cars use the hollow shaft), and the inner and outer ends of each have a universal joint (U joint) through the spline on the universal joint and the inner ring of the reducer gear and the hub bearing.

Half shafts are used to transfer power between the differential and the drive wheels. The half-shaft of the ordinary non-disconnecting drive axle can be divided into three types: full floating, 3 4 floating and semi-floating according to the different forms of external support.

Extended informationAutomobile drive shaft, the transmission device designed to drive the wheels is located at the end of the automobile drive train, and its function is to transfer torque from the differential half-shaft gear to the driving wheels. In the disconnecting drive axle and the steering drive axle, the transmission device that drives the wheel comprises a half-shaft and a universal joint transmission device, and the constant velocity universal joint is mostly adopted.

The drive shaft is fast and easy to optimize, and the automatic selection is included. In the general non-disconnecting drive axle, the transmission device that drives the wheels is the half shaft, and the half shaft connects the differential half shaft gear with the hub. On the drive axle equipped with a wheel side reducer, the half shaft connects the half shaft gear with the drive gear of the wheel side reducer.

The half shaft of the ordinary non-disconnecting drive axle is divided into three types: semi-floating, 3 4 floating and full floating according to the different support types or stress conditions at the outer end. The semi-floating half-shaft is directly supported on the bearing placed in the inner bore of the outer end of the axle housing with a journal close to the outer end, and the end is fixed to the wheel hub by a journal and key with a tapered surface, or directly connected to the wheel disc and brake drum by a protrusion.

Therefore, in addition to transmitting torque, the semi-floating half-shaft also has to withstand the bending moment transmitted by the wheels. It can be seen that the load of semi-floating half bearing is complex, but it has the advantages of simple structure, small weight, compact size and low cost. It is used for cars and light trucks with small mass, good use conditions and low load.

Photo by Pacific Automobile Network Q&A).

The stop ring is fixed.

The retaining ring with the shaft is embedded in the groove of the shaft, mainly used when the axial force is not large and the speed is not high, the shaft end retaining ring fixed with the screw is fastened, which can be used to bear large axial force at high speed, and the screw nailing should have anti-loosening measures.

It is positioned with a tapered sleeve, fastened with a stop washer and a round nut, and is used for bearings on optical shafts with tapered bore inner rings. In order to prevent the bearing from moving axially relative to the shaft or housing hole when the bearing is quietly bearing the axial load, the inner ring and the shaft, the outer ring and the housing hole of the bearing must be fixed in the opening direction of the shaft, and the axial fixing mode of the inner and outer rings commonly used in rolling bearings is carried out.

Common support bearings are:

1. Single-row ball slewing bearing.

The single-row four-point contact ball slewing ring is composed of two seat rings, which are compact in structure, light in weight, and the steel ball is in contact with the arc raceway at four points, which can bear the axial force, radial force and tipping moment at the same time. Construction machinery such as rotary conveyors, welding manipulators, small and medium-sized cranes and excavators can be selected.

2. Single-row crossed roller slewing ring.

Single-row cross roller slewing ring, composed of two seat rings, compact structure, light weight, high manufacturing precision, small assembly clearance, high requirements for installation accuracy, rollers are 1:1 cross arrangement, can bear axial force, tipping moment and large radial force at the same time, is widely used in lifting and transportation, construction machinery and military products.

3. Double volleyball slewing bearing.

The double-row ball type slewing ring has three seats, and the steel balls and isolation blocks can be directly discharged into the upper and lower raceways, and the upper and lower two rows of steel balls with different diameters are arranged according to the stress condition. This kind of open macro trap assembly is very convenient, and the bearing angle of the upper and lower arc raceways are both.

It is 90° and can withstand large axial forces and tipping moments. When the radial force is greater than the axial force, the raceway must be specially designed.

Materials used. 1. Materials for ferrules and rolling elements.

In general, the slewing ring bearing ring is made of surface hardened steel, when the user has no special requirements, it is generally made of 50mn steel, but sometimes in order to meet the needs of the host in some special applications, other grades of surface hardened steel can also be selected according to the specific use conditions provided by the user, such as 42crmo, 5crmnmo, etc.

2. Materials for cages.

Cages for slewing ring bearings are available in integral, segmented, and isolated block configurations. Among them, 20 steel is used for integral and segmented cages.

or ZL102 cast aluminum alloy manufacturing. With the continuous development of the material industry, nylon has also been popularized and applied in the design of segmented cages.

3. Materials for sealing rings.

The material used for the sealing ring of the slewing ring bearing is made of oil-resistant butadiene rubber. The code of the ferrule material and the state of the blank ** is according to the provisions of the table, the "t" in the table indicates that the ferrule blank is in the quenched and tempered state**, and "z" indicates that the ferrule blank is in the normalized state**.

What is the support of the differential half-shaft gear - the half-shaft gear hole of the differential shell is a round hole with oil grooves

Fully floating and semi-floating, the full floating type is the most widely used....