Types of Steering Linkages

Types of Steering Linkages:

There are three basic types of steering linkages used in passenger vehicles and light trucks. These include the rack and pinion linkage, parallel linkage, and Haltenberg steering linkage. There are variations of these linkages, but these are the three fundamental types. The parallel and Haltenburg linkages are used with a steering gear box. The rack and pinion linkage is used with a rack and pinion steering gear.

Fig 1: Rack & Pinion Linkage

The rack and pinion linkage, which is by far the most common steering linkage, consists of inner and outer tie-rod ends on each side and steering knuckles or arms. Advantages of this linkage include precise steering geometry, simple design, and relatively low weight and cost. Disadvantages include relatively low carrying capacity and inflexibility when it comes to fitting around other vehicle components. As the driver turns the steering wheel, the shaft that runs from the steering wheel to a pinion gear (1) causes the pinion gear to turn. As the pinion gear turns it causes the rack (2) to move side to side. As the rack moves side to side it will push the tie rod ends (3) and the steering anus (4) in the desired direction thus t lulling the wheels.

Fig 2: Parallel linkage

The parallel linkage consists of a pitman arm, idler arm, center link, tie-rods, tie-rod ends, steering knuckles or arms, and possibly a steering stabilizer. Advantages of this linkage include precise geometry, high strength, and it can be designed to fit around other vehicle components. The main disadvantages are cost, relatively higher weight, and more components to wear out.

As the driver turns the steering wheel the shaft which runs from the steering wheel to a steering gear (1) rotates causing the pitman arm (2) to rotate. The pitman arm is connected to a center link (3), which will move side to side. This side to side motion will cause the tie rod end/sleeve assembly (4) and steering arms (5) to move thus turning the wheels in appropriate direction. The idler arm (6) connects the steering linkage to the frame and keeps everything parallel and aligned properly. 

Fig 3: Haltenberg linkage

The Haltenberg linkage consists of a pitman arm, drag link, tie-rods, outer tie-rod ends, steering knuckles or arms, and possibly a steering stabilizer. Advantages of this linkage include very high strength, lower cost than parallel linkage, and can be designed to fit around other vehicle components. The main disadvantage is the steering geometry is not precise. As the driver turns the steering wheel the shaft which nuts from the steering wheel to a steering gear (1) rotates causing the pitman arm (2) to rotate. The pitman arm is connected to a drag link (3), which will move side to side. This side to side motion (or dragging) will cause the tie rod end (4) and steering arms (5) to move thus turning the wheels in the appropriate direction.

Other types of steering linkages: (according to arrangement)

1.      Conventional steering Linkage

2.      Direct cross type steering linkage

3.      Three piece steering linkage

4.      Center arm steering linkage

5.      Relay type steering linkage.

These types of geometrical linkages are widely design for to solve out the problem of inner and outer wheels while taking a turn to trace out circles of different radii.