The camshaft is a long shaft with lobes (cams) attached to it, usually found in Internal Combustion Engines. It controls and operates the opening and closing mechanism of inlet and outlet valves. They also determine the amount of air-fuel mixture pumped into the combustion chamber. As the camshaft rotates, the lobes push the rocker arm and hence opens the inlet valve. The springs on the valves help in returning them to a closed position on completing a rotation. In modern cars and bikes, these camshafts are placed above the cylinder head for more convenience. It is known as Double Overhead Cams (DOHC) and Single Overhead Cams (SOHC). Moreover, camshafts are one of the critical components of an IC engine which regulates the combustion.
As we mentioned earlier, how can we avoid or replace such an indispensable part from an engine? Is it sensible to run an engine without camshafts? A Swedish company called "FreeValve" has all the solutions. It is the sister concern of the hypercar maker Koenigsegg Automotive AG. This company has succeeded in developing and implementing a camless engine on SAAB cars of Sweden. Furthermore, the Chinese carmaker Qoros has introduced a concept car called 'QamFree" featuring the FreeValve technology. It was debuted at the 2016 Guangzhou Motor Show in China. This system works with the help of a 'fully variable valve actuation' enabling the independent control of inlet and exhaust valves of an IC engine.
Here, the FreeValve concept uses Electro-pneumatic-hydraulic valves are combined with position sensors to control the sequence. Unlike camshaft-operated valves, this is much easier and can deliver the optimum amount of air-fuel mixture, according to the demand. Moreover, FreeValve system can deactivate or activate the working of any engine at will,i.e., a 4-cylinder engine can be converted to 2-cylinder, which in turn reduce emission and increases the fuel efficiency.
This particular technology has been successfully installed and tested in SAAB 9-5 model for three years. Within that period, it has covered over 55,000 km and even has engine start ability down at 20-degree Celsius.
Advantages of FreeValve
The use of a camless engine can make the working of an IC engine a lot better from the conventional way. The 'QamFree' is a concept model introduced by the Chinese maker Qoros based on their Qoros 3 GT, powered by a 1.6-litre, 4-cylinder turbocharged petrol engine.
The performance figures of the QamFree is really fascinating as it delivers 233 bhp of maximum power and 320 Nm of maximum torque, compared to the 156 bhp and 230 Nm of the standard version, i.e, there are 48% and 38% of an increase in power and torque. Besides these performance figures, fuel consumption has been also reduced from 12 to 17 percent from the conventional 4-cylinder engine with 50% decrease in the emission. Due to the absence of several mechanical parts, this car weighs 20kg lighter and therefore is cheaper to manufacture in large volume.
Camless engines can be also installed in ships. As these are equipped with sensors, it can diagnose and run effectively without any sorts of repairing or maintenance. Moreover, the engine life and status can be estimated with the help of software updating.
Even though it has been successfully installed and tested on the SAAB models, real-world testing is still going on. FreeValve claims this to be as cheap. However, it will be expensive for the automobile manufacturers at the initial stages. Afterall, this technology has been completely developed by FreeValve. Therefore others have to pay loyalty for adapting this particular technology.