What is a pitman arm steering system and what are its components?
What is a pitman arm steering system and what are its components?
A Pittman arm is a method to reduce the problem of turning geometry. If you sit down with a straight edge and compass, and draw the tracks of wheels going around a corner, you will find that the inner and outer wheel's ideal angles are different. This is called "toe-in." The Pittman arm helps this, by causing a difference in how far each wheel pivots around the turning knuckle. The Pittman is linked to a short stub that is parallel to the wheel, and that's what actually provides the force to the steering upright. Pittman arms are used when the turn has to be tight, like for tractors and road building equipment.
The idea is to reduce the amount the tires scrub as they are forced through the turn.
To turn the Pittman arm a worm on a helical gear was popular, since it eliminated kick back.
The rack and pinion system is another way to move the steering links. It uses a toothed gear on a toothed bar, or rack. You turn the gear, the rack moves sideways. It is more precise and positive, and was popular in sports cars.
The idea is to reduce the amount the tires scrub as they are forced through the turn.
To turn the Pittman arm a worm on a helical gear was popular, since it eliminated kick back.
The rack and pinion system is another way to move the steering links. It uses a toothed gear on a toothed bar, or rack. You turn the gear, the rack moves sideways. It is more precise and positive, and was popular in sports cars.