Drive shaft structure optimization
The drive shaft is subjected to alternating stresses such as torsion, shear, tension and compression, and impact, which can also cause torsional and bending vibrations of the drive shaft, resulting in additional stress; uneven stress distribution; sliding friction between the drive journal and the bearing. The main failure modes of the drive shaft are fatigue fracture and severe wear of the journal. Therefore, the material should have high strength, certain impact toughness, sufficient bending, torsional fatigue strength and stiffness, and the journal surface should have high hardness and wear resistance. Such materials are medium carbon alloy steels, which are heat treated by quenching and tempering (or normalizing) to enhance and improve processability. In recent years, a new type of steel has been widely used in high-power engines, that is, alloy quenched and tempered steel, that is, by adding Si, Cu, Ti and other alloying elements to refine the grains, strengthen the steel matrix, and improve the strength of the steel.
Optimization of drive shaft structure The drive shaft relies on the spline and tapered shaft to cooperate with the planet carrier to transmit torque. The taper fit often fails to transmit torque due to the loosening and wear of the eccentric bolts. Therefore, the drive shaft structure needs to be improved. Quick and easy automatic selection of drive shafts is included. Remove the tapered part of the drive shaft, and design the drive adapter plate and the spline shaft as two independent parts, the adapter plate is designed as an internal spline groove that matches the drive shaft spline, and the drive shaft spline is designed as a whole-body spline to transmit torque, so that , The torque is completely transmitted by the spline shaft and the planet carrier, and the spline shaft will no longer cause stress concentration due to the excessive cross-section and uneven strength of the taper shaft, thereby improving the strength of the driveable shaft.
car drive shaft The transmission designed to drive the wheels is located at the end of the car's driveline, and its function is to transmit torque from the differential side gear to the drive wheels. In the disconnected drive axle and the steered drive axle, the transmission device for driving the wheels includes half shafts and universal joint transmission devices, and constant velocity universal joints are mostly used. Quick and easy automatic selection of drive shafts is included. On a general non-disconnect drive axle, the transmission device that drives the wheels is the half shaft, which connects the differential half shaft gear to the hub. On the drive axle with the wheel reducer, the half shaft connects the half shaft gear with the driving gear of the wheel reducer. The half shafts of ordinary non-disconnected drive axles are divided into three types: semi-floating, 3/4-floating and full-floating, according to the support type or stress condition of the outer end. The semi-floating axle shaft is directly supported on the bearing placed in the inner hole of the outer end of the axle housing by the journal close to the outer end, and the end is fixed with the wheel hub by the journal with a tapered surface and the key, or by the flange. It is directly connected with the wheel disc and the brake drum). Therefore, in addition to transmitting torque, the semi-floating axle shaft also bears the bending moment transmitted by the wheels. It can be seen that the load of the semi-floating semi-bearing is complex, but it has the advantages of simple structure, small mass, compact size and low cost. It is used for sedans and light trucks with small mass, good service conditions, and small carrying load.