The Steering System:
Cam And Lever Steering Gear
 In the cam and lever steering gear, the worm is known as a cam. The inner end of the pitman arm shaft has a lever that contains a tapered stud. The stud engages in the cam so that the lever is moved back and forth when the cam is turned back and forth.
When the tapered stud is fixed in the lever so that it can't rotate, there is sliding friction between it and the cam. Therefore, on some vehicles with this type of steering gear, the stud is mounted in bearings so that it rolls in the cam groove (threads) instead of sliding.
Some large trucks use a cam and twin-lever steering gear. This is nothing more than a cam and lever gear with two tapered studs instead of one. The studs may be fixed in the lever, or they may be mounted on bearings. |