tailieunhanh - Advanced Vehicle Technology Episode 2 Part 4

Tham khảo tài liệu 'advanced vehicle technology episode 2 part 4', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Fig. Final drive with third differential and lock and optional transfer gearing for front the input shaft directly with the input helical gear and left hand bevel sun gear so that the differential planet pinions are prevented from equally dividing the input torque between the two axles at the expense of axle speed differentiation. Consequently when the third differential is locked out each axle is able to deliver independently to the other axle tractive effect which is only limited by the grip between the road wheels and the quality of surface it is being driven over. It should be observed that when the third differential lock-out is engaged the vehicle should only be operated at slow road speeds otherwise excessive transmission wind-up and tyre wear will result. Front wheel drive transfer gear take-up Fig. An additional optional feature is the transfer gear take-up which is desirable for on-off highway applications where the ground can be rough and uneven. With the front wheel drive lock clutch engaged 25 of the total input torque from the gearbox will be transmitted to the front steer drive axle while the remainder of the input torque 75 will be converted into tractive effect by the tandem axles. Again it should be pointed out that this mode of torque delivery and distribution with the third differential locked-out must only be used at relatively low speeds. 252 Fig. a and b Tandem drive axle layout Worm and worm wheel inter axle with third differential Fig. Where large final drive gear reductions are required which may range from 5 1 to 9 1 either a double reduction axle must be used or alternatively a worm and worm wheel can provide a similar step down reduction. When compared with the conventional crownwheel and pinion final drive gear reduction the worm and worm wheel mechanical efficiency is lower but with the double reduction axle the worm and worm wheel efficiency is very similar to the latter. Worm and worm wheel axles usually .