Automotive blog full of fragrant content!
Tuesday November 21st 2017

Categories

Power steering

Power steering

Nowadays almost all cars have power steering. But this luxury only started being fitted to cars in the 1950s. Chrysler Corporation, which was the first manufacturer  to intrude power steering to commercially available vehicles, called its hydraulic system “Hydraguide”. Power steering is a need these days since it increases driving pleasure, comfort and safety. It would be very tiring to steer without any aid specially at low speeds.

Since the invention of the power steering the principle has kept more or less the same. Most manufacturers use a hydraulic system to reduce the torque you need to apply to make the wheels steer. The principle is that when you steer some hydraulic pressure is driven to the steering rack piston and this pressure assists you in the steering load that needs to be applied.

The next video explains perfectly how hydraulic power steering works:

But, hydraulic steering systems have several disadvantages. They consume energy from the engine even when there is no steering needed. This is because hydraulic systems always need to keep the hydraulic fluid pressurised. Another disadvantage is that because is a pressurised system lots of effort needs to be put on the design to make a perfect seal. Moreover, the hydraulic system is quite complex which it makes it heavy and prone to failure. Not to say that hydraulic steering is a bit primitive. To reduce all this disadvantages some brands have started fitting electric power steering to their cars.

Electric power steering helps you steering by means of an electric motor. A control unit takes inputs from various sensors and decides what amount of torque needs to be applied. Watch the following video for more information:

The advantages of an electric power steering are that only consumes energy when steering is applied, so fuel consumption is reduced. It is a lot lighter and simpler than an hydraulic system and therefore less prone to failure. Another big advantage is that the torque aid is adjustable depending on the driving situation.

On the other hand, some people argue that electric power steering systems do not give the feedback an hydraulic does.

It needs to be said that the previous statements are only true for passenger cars. In case of heavy load vehicles or high performance applications the hydraulic system is by far the best steering aid you can implement.

Other technologies like active and integral steering are starting to be broadly applied because they come full of advantages. Let’s take a look at those.

Active power steering can modify the amount of steering aid and the amount you need to turn the wheel to get the same wheel lock. All this is controlled electronically according to several data inputs. You may want to watch the following video to broaden your understanding.

Integral power steering improves the handling of the car by making all 4 wheels of a car directional. So, on a tight bend for example, the rear wheels will turn slightly to reduce the turning radius. It needs to be said that it is not a new technology, the Honda Prelude had it more than 20 years ago. Some of the manufacturers that apply this technology nowadays are Renault and BMW.

In the following video you can see the system fully operational:

On this video you can see a 1991 Honda Prelude with 4WS:

References:

http://en.wikipedia.org/wiki/Power_steering

http://www.bmw.com/com/en/insights/technology/efficient_dynamics/phase_2/technologies/electric_power_steering.html

http://www.carblogindia.com/electric-power-steering-vs-hydraulic-power-steering/

Leave a Comment

Also interesting!

BMW Innovations High Precision Injection
BMW Innovations High Precision Injection

High Precision Injection gets the most out of every single drop of fuel. The most efficient way to use fuel, the [Read More]

BMW Innovation Head Up Display
BMW Innovation Head Up Display

View all your critical driving information right in front of you, so your focus is kept on the road where it belongs. [Read More]

BMW Innovation Surround View
BMW Innovation Surround View

Surround View delivers a 270° view around your BMW, giving you a new way of looking at the road. // // [Read More]

BMW Innovation Start Stop
BMW Innovation Start Stop

Why burn fuel when you don’t need to? Automatic start stop system stops the engine when you come to a complete [Read More]

BMW Innovation Night Vision
BMW Innovation Night Vision

Your command of the road doesn’t end when the sun sets. BMW Night Vision cuts through the dark to illuminate the [Read More]