It used to be that if you wanted to drive, you had to have the arms for it. Older cars did not have power steering, and parking or even turning at low speeds could require a lot of strength to move the steering wheel on a big, heavy car. The wheel itself was huge, too, to help provide the leverage needed so that is why you need to know the power steering basics.
Power Steering Basics History
The first power steering system on a vehicle was apparently installed in 1876 by a man with the surname of Fitts, but little else is known about him. The next power steering system was put on a Columbia 5-ton truck in 1903 where a separate electric motor was used to assist the driver in turning the front wheels.
In 1951, Chrysler was the first automaker to offer power-assisted steering to consumers, and other manufacturers soon followed. Every new vehicle sold in Canada today comes with power steering. While some still use a hydraulic system as with those first easy-steer models, automakers are increasingly switching to electric systems, and there is even a system that is a combination of the two.
Starting in the mid-1950s American manufacturers offered the technology as optional or standard equipment while it is widely offered internationally on modern vehicles, owing to the trends toward front-wheel drive, greater vehicle mass, reduced assembly line production costs, and wider tires, which all increase the required steering effort. Heavier vehicles, as are common in some countries, would be extremely difficult to maneuver at low speeds, while vehicles of lighter weight may not need power assisted steering at all.
Most vehicles use rack-and-pinion steering. The rack is a notched metal bar between the front wheels, while the pinion is a small gear with teeth that mesh with those in the rack. Turning the steering wheel turns the pinion gear. This moves the rack to the right or left, which turns the vehicle’s wheels.
Without power assist, you would need grunt force to turn the pinion and move the rack. As its name suggests, hydraulic power steering uses the force of pressurized hydraulic fluid to assist with the steering, working whenever the driver turns the steering wheel. The fluid is pressurized by a pump, which gets its power via a belt attached to the engine. The system requires some maintenance, including replacing the belt if it gets too worn, and making sure there is enough fluid in the reservoir. A hydraulic power steering system will make a squealing noise if the steering wheel is turned all the way and held hard – it’s saying “ouch,” and releasing the wheel slightly should stop the noise – but if it’s noisy whenever the wheel is turned, or if it takes more effort to steer the car, it’s usually an indication that the system is low on fluid.
What is Power Steering?
All modern cars have power steering—a feature that assists the driver in turning the front wheels. The power steering system makes the steering wheel easier to turn by augmenting the force the driver exerts on the vehicle’s mechanical steering gear.
Most vehicles have either electric power steering (EPS) or hydraulic power steering. There are also a few models that use an electro-hydraulic system, which combines elements of both the EPS and hydraulic designs.
The steering gear contains a set of gears that transfer input from the steering column shaft (and the steering wheel) to the steering linkage. From there, the steering linkage connects to the steering knuckles, which, in turn, attach to the wheels and tires. All the components working together cause the wheels to move in or out in response to the driver’s input.
The steering gear either rack-pinion or steering box design contains a set of gears that transfer input from the steering column shaft (and the steering wheel) to the steering linkage.
Hydraulic Power Steering
Many vehicles on the road today still have hydraulic power steering. The design uses an engine-driven pump and hydraulic fluid to provide steering assist. A typical hydraulic system includes the following power steering components:
Steering Gear (Rack and Pinion Assembly or Worm Gear Box)
Hydraulic power steering systems may use either a steering rack and pinion assembly or steering box, depending on the vehicle design. Both types of units contain a set of gears that transfer input from the steering column shaft (and the steering wheel) to the steering linkage.
From there, the steering linkage connects to the steering knuckles, which, in turn, attach to the wheels and tires. All the components working together cause the wheels to move in or out in response to the driver’s input.
Power Steering Pump
The power steering pump, which is driven off the engine by a belt, pressurizes the power steering fluid and sends that fluid to the power steering gear. When the pressurized fluid acts on the gear, it makes the steering wheel easier to turn for the driver.
Reservoir
Pressurized hydraulic power steering fluid acts as the medium that applies force to the steering gear. A reservoir—mounted either remotely or on top of the power steering pump—stores the fluid.
Hoses
A set of hoses (or lines) connect the steering gear to the power steering pump. The hose that carries pressurized fluid from the pump to the gear is called the pressure hose. Meanwhile, the hose that routes fluid from the gear back to the pump is called the return hose.
Electronic Power Steering
A typical electronic power steering system diagram
EPS, which is found in nearly all new cars, uses an electric motor to act on the steering gear and provide steering assist. A typical EPS system includes the following power steering components:
Steering Gear (Rack and Pinion Assembly)
Steering Motor
An electric motor (mounted on either the steering column or steering rack) is the focal point of the EPS system. The motor applies the force needed to turn the steering gear and provide the driver with steering assist. Depending on the system design, the motor may operate on twelve volts (like most automotive electrical components) or forty-eight volts.
Control Module
A computer, which is often referred to as the EPS control module, operates the steering motor based on input from the steering system sensors. To retrieve additional information regarding vehicle operation, the EPS module also communicates with other onboard modules over a data network.
The steering wheel sensor, which is usually an angle sensor and a torque sensor integrated into a single assembly, is the primary input to the EPS module. There is also a sensor that relays the position of the motor back to the EPS module.
Finally
Back in the day—before the invention of the cell phone, the personal computer, or even the color television—nearly all production cars had manual steering. The setup primarily relied on the driver’s muscles to turn the car’s front wheels back and forth via the steering wheel. Once you understand power steering basics then you can decide if you want to convert your car from manual steering to power steering.
Interesting facts. I like this type of stuff
Thank you
This is very interesting, You are an overly skilled blogger.
I have joined your rss feed and sit up for in the hunt for more of your great post.
Also, I have shared your website in my social networks