Research Of High Friction Worm Gear Differential In Rear Drive Axle

Worm Gear-Worm drive is widely used as its good self-locking function. TorsenLSD, which is a representative invention of the worm gear-worm drive, just has beenused in some light vehicle to keep the balance of the front axle torque and rear axletorque. With the development of the new technology, new materials and new processingmethods have greatly improved the performance of the worm gear-worm drive. A highfriction worm gear differential in rear drive axle which has a new complicated case andnew material worm gear is developed in this paper, and it is very important for ourautomobile industry as its obvious advantages which are the big transfer torque, highefficiency and good self-locking function.(1)The function of the traditional vehicle has been researched, and the drivecharacteristics are analysed, also the advantages and disadvantages are discussed. Inorder to make the torque distribution reasonable, the self-locking function of the wormgear-worm differential is been studied. The more torque is been distributed to one sideof the drive axle when the other side of the axle is slipping. In that way, the driving andoperating performance have been developed.(2)The disadvantage of the traditional Torsen LSD has been analysed. A new wormgear-worm differential which has a compound case has been designed after anslysingthe structure of the differential. The compound case is divided into four parts, atraditional case and a sleeve structure which also can be divided into three parts. Thecase can make the complicated and high precision requirement assemble to be moreeasy and quicker, the economic benefit is also been brought out.(3)The high friction worm gear-worm differential is designed based on a kind of thedomestic heavy-duty truck which is a mass production. The driving features whichinclude locking coefficient, torque distribution coefficient, efficiency and drivingefficiency are discussed. The new materials are used in the differential, for example theworm gear is made of45CrNiMoVA and worm is made of38CrMoAl, the two newmaterials have a high yield stress limitation, so the big torque of the heavy-duty truckcan be transmitted by the worm gear.(4)The parametric modeling programs of the worm gear, worm and spur gear havebeen established after analyzing the secondary development technology of the UG6.0.These components have a lot of complicated curve and require a highly precision. It isvery tedious and error prone if you modeling directly. The different models can be built by changing the parameters such as spiral angle, number of threads of worm, centerdistance and so on. As a result, the time used in modeling and structure optimizingcould be strongly decreased.(5)The static simulation of the high friction worm gear-worm differential which hasa complicated case structure have been done by using the ansys12.0, and the distributionof the stress and deformation are obtained. The rigid dynamic and the rigid-flexiblecoupling dynamic of the worm gearing in the new differential are presented by using theAdams and the Hyperworks, the stress in coordinate direction, the angular accelerationand the displacement are showed in the result while the worm is regarded as the rigidbody and the rigid-flexible coupling body.