If you drive a modern car, most probably is equipped with a power steering rack. But, have you ever wondered what it would feel like to turn the direction of your wheels using a manual steering rack?
Needless to say, power steering has come a long way. We’ll trace back the journey of technological enhancements in steering racks to help you understand the history of power steering.
But first, here’s a brief look at reasons for power steering’s steep rise in popularity, and why it is an almost must-have in every vehicle unit coming out of production today — except lightweight sports cars, of course.
Benefits of Power Steering
Power-assisted steering has a number of benefits that make it an essential component in many vehicles on the road today. These benefits include:
1. Less effort needed when steering heavy vehicles
The energy needed to make the seemingly endless rotations on a manual steering in a heavy and/or long vehicle is a lot. For some, this puts a damper on the fun of driving.
With a power assist, the steering becomes augmented through mechanical components, reducing the effort needed to steer a vehicle.
2. Easier to steer vehicles with wider tires
If you attempt making a turn on the road or pulling up at a parking spot on a manual steering vehicle with wide tires, you will appreciate that it is strenuous.
Power steering is essential for any vehicle with wide wheels, and is why some owners with wide-wheeled manual steering vehicles modify the steering rack to power steering.
3. Less strain when driving at slow speeds
The characteristic slow-moving traffic on city roads makes the driving experience an arduous one for drivers of manual steering automobiles.
With power-assisted steering, the exhaustion drivers experience is greatly reduced when driving at slow speeds, making for greater enjoyment when driving.
One concern for many drivers is that power-augmented steering takes away the feel of the road. To address this, many vehicles with power steering racks are equipped with speed sensing steering systems. Their function makes them appear like a blend of the two steering systems.
A speed sensing/sensitive steering system reduces the torque applied by the power steering when the vehicle is cruising at high speeds to allow a driver get a more authentic feel of the road. At lower speeds, the system increases the power-augmented torque applied to allow the driver maneuver with less effort.
Origin of Power Steering
Owing to the challenges presented by manual steering, efforts to invent mechanically-augmented steering systems were initiated. This dates back centuries — some sources quote 1876 as the year when the first ever power steering gear was introduced in an automobile. The inventor, G.W. Fitts, is credited with the invention, although not much is known about him.
The invention of a vehicle power steering system may have been inspired by the successful steam-powered engine amplifier manufactured by George Forrester and Company and introduced to the Great Eastern ship’s engine a decade earlier.
It wasn’t until the turn of the century, in 1900, when a patent was awarded for a four-wheel drive system that included a ‘power steering mechanism’ that the invention really begun to take shape. The inventor of this revolution was Robert E. Twyford, a resident of Pittsburgh, Pennsylvania.
From Design to Reality: Engineer Francis W. Davis
Two decades later, the paper design for the power steering system was made practical by Francis W. Davis, who, at the time, was an engineer assigned to Pierce Arrow’s truck division. After his demonstration, he moved to General Motors in 1926, where he would continue to innovate the promising technology.
This led to the formulation of a hydraulically-augmented power steering system that proved a sensation. Except, there was one issue: General Motors assessed the system as being impractical to mass-manufacture because its production costs were just too steep. The economics of it were compounded by the ailing economy witnessed during the Great Depression.
In 1936, the highly sought-after engineer moved companies again, this time contracted by automotive parts manufacturer, Bendix Corporation. But like in GM, his innovations never made it to mass production.
World War II, a Catalyst in the Enhancement of Power Steering Systems
A number of technological equipment in use today were vigorously developed during the World War II. Power steering is one of them. Heavy automobiles used in war, such as armored cars and tank recovery vehicles required easy maneuvering, and engineer’s turned to Davis’ patents for the solution to this problem.
This saw more than 10,000 units of power steering systems equipped in automobiles used in the war.
Commercial Production: Chrysler’s Hydraguide
In the U.S, patents have a validity period of 20 years from the date of issue. It had been more than two decades since Davis patented his power steering designs when Chrysler made the first significant step in inclusion of hydraulic power steering systems in of commercially available automobiles using David’s’ patents.
The system, christened the Hydraguide, was a worthy addition by the Chrysler Corporation in its Imperial model in 1951. Its popularity with motorists spurred other manufacturers to develop their own power steering systems.
Hydraulic Power Steering Systems in the Mass Market
Owing to the success of Chrysler’s Hydraguide, General Motors revived its interest in the hydraulic power system technology. Other manufacturers, too, followed suit, dedicating their efforts to producing similar systems for their steering systems.
The popularity of front wheel drives, in particular, made power steering an essential component in vehicles, as it provided both safety and convenience options for drivers.
In as little as two decades, hydraulic power systems had been fitted into millions of vehicles on the road.
Electric & Electrohydraulic Power Steering Systems
These two enhancements constitute the most significant innovation in power steering systems used today. They differ from the hydraulic power system in how torque is applied: the hydraulic power system generates torque from the engine using a hydraulic motor, while electric and electrohydraulic power steering systems draw their power from electric motors on need-be basis.
Thanks to the electric motors, electric and electrohydraulic power steering systems provide better maintenance and fuel economy compared to hydraulic power steering systems.
Sam is Automole’s editor-in-chief and classic car enthusiast. Sam is studying mechanical engineering at Cockrell School of Engineering, Austin. He also writes for many top automotive publications and appears on the Collecting Cars Podcast.