Community hub
Recent from talks
Knowledge base stats:
Talk channels stats:
Members stats:
Camless piston engine
A camless or free-valve piston engine is an engine that has poppet valves operated by means of electromagnetic, hydraulic, or pneumatic actuators instead of conventional cams. Actuators can be used to both open and close valves, or to open valves closed by springs or other means.
Camshafts normally have one lobe per valve, with a fixed valve duration and lift. Although many modern engines use camshaft phasing, adjusting the lift and valve duration in a working engine is more difficult. Some manufacturers use systems with more than one cam lobe, but this is still a compromise as only a few profiles can be in operation at once. This is not the case with the camless engine, where lift and valve timing can be adjusted freely from valve to valve and from cycle to cycle. It also allows multiple lift events per cycle and, indeed, no events per cycle—switching off the cylinder entirely.
Camless valve trains have long been investigated by several companies, including Renault, BMW, Fiat, Valeo, General Motors, Ricardo, Lotus Engineering who developed electro-hydraulic valve actuation in the late 1980s as a spinoff of their active suspension program (both utilised similar electro-hydraulic actuation and control), Ford, Jiangsu Gongda Power Technologies, and Koenigsegg's sister company FreeValve. Some of these systems are commercially available, although not yet[as of?] in engines in production road vehicles. In the Spring of 2015, Christian von Koenigsegg told reporters that the technology pursued by his company is "getting ready for fruition", but said nothing specific about his company's timetable.
In November 2016, Chinese automobile manufacturer Qoros Auto displayed the Qoros 3 hatchback at the 2016 Guangzhou Motor Show, which showcased a new Qoros "Qamfree" engine. The engine's Swedish designer FreeValve claims that the 1.6-litre (98 cu in) turbocharged engine will produce 170 kW (230 hp) and 320 N⋅m (240 lb⋅ft) of torque. They also claim that, compared to a similar traditional engine, it offers a 50% reduction in size (including a 50-millimetre-lower (2.0 in) height), 30% reduction in weight, 30% improvement in power and torque, 30% improvement in fuel economy, and a 50% reduction in emissions. Christian von Koenigsegg claims in a video that the Qamfree engine with the PHEA camless technology is based on an existing Qoros engine that was "...developed in Germany and Austria five, six years ago...".
Christian von Koenigsegg also claims that the PHEA camless technology allows the elimination of the pre-catalytic converter, because the standard catalytic converter can be brought up to temperature quickly by manipulating the exhaust cycle.
Because camless engines have no camshaft, they may have fewer moving parts. In these systems, the camshaft follower, rocker arms, and/or pushrods have been replaced by an electro-hydraulic actuator system which uses the existing oil pumps, thus reducing development risks of the new system by employing existing technology. Direction changing on older B&W MC engines was engaged by physically changing the direction of the cam roller, whereas with the new camless engine, it is controlled by a computer. This eliminates the risk of mechanical failures that could damage the engine if there was a malfunction while changing directions. Additionally, because there is no chain connection between the crankshaft and the camshaft, the engine is lighter with fewer points of failure. The absence of a camshaft also means that the parasitic load on the engine is lower, which is particularly useful in large marine engines, as it can equate to a large amount of power savings. With a camless engine, fuel injection and exhaust timing are directly controlled by an engine control unit and can be constantly changed and adjusted without stopping the engine. This allows for the engine to run at a lower RPM, a feature useful in ships as it allows better low speed maneuvering while docking. Additionally, when a ship is maneuvering, the computer controlled fuel injection and valve timing allows for faster RPM control, hence faster stopping in emergency situations.
Solenoid valves are used to control valve activation that is electronically operated. These are used for controlling liquid or gas flow and are most commonly used in fluidics as control elements. They are multifunctional in a way to release, shut off, mix, or distribute fluids with high reliability and fast processing. The market for solenoid valves is growing with the imperative growth in all the regions. Increasing application areas year on year and advancement in technology and developed fluid automation technologies, all are driving the market on a global scale.
Conventional mechanical camshaft actuation is capable of generating extremely high forces which, combined with very high stiffness/low mechanical compliance of a conventional modern valve train layout, are used to very accurately and consistently control the position the engine valves. This enables very high levels of valve acceleration and lift and also very small valve-to-valve and valve-to-piston clearances to be used in combination with very high engine speeds. For example, prior to the FIA restrictions, Formula 1 engines ran at speeds of over 20,000 RPM and power outputs of over 330bhp/litre normally aspirated using a conventional camshaft and mechanical valve actuation; it is extremely unlikely that this high engine speed and output can be achieved with camless valve actuation.[citation needed] At 20,000 RPM, the valves open and close 166 times per second.
Hub AI
Camless piston engine AI simulator
(@Camless piston engine_simulator)
Camless piston engine
A camless or free-valve piston engine is an engine that has poppet valves operated by means of electromagnetic, hydraulic, or pneumatic actuators instead of conventional cams. Actuators can be used to both open and close valves, or to open valves closed by springs or other means.
Camshafts normally have one lobe per valve, with a fixed valve duration and lift. Although many modern engines use camshaft phasing, adjusting the lift and valve duration in a working engine is more difficult. Some manufacturers use systems with more than one cam lobe, but this is still a compromise as only a few profiles can be in operation at once. This is not the case with the camless engine, where lift and valve timing can be adjusted freely from valve to valve and from cycle to cycle. It also allows multiple lift events per cycle and, indeed, no events per cycle—switching off the cylinder entirely.
Camless valve trains have long been investigated by several companies, including Renault, BMW, Fiat, Valeo, General Motors, Ricardo, Lotus Engineering who developed electro-hydraulic valve actuation in the late 1980s as a spinoff of their active suspension program (both utilised similar electro-hydraulic actuation and control), Ford, Jiangsu Gongda Power Technologies, and Koenigsegg's sister company FreeValve. Some of these systems are commercially available, although not yet[as of?] in engines in production road vehicles. In the Spring of 2015, Christian von Koenigsegg told reporters that the technology pursued by his company is "getting ready for fruition", but said nothing specific about his company's timetable.
In November 2016, Chinese automobile manufacturer Qoros Auto displayed the Qoros 3 hatchback at the 2016 Guangzhou Motor Show, which showcased a new Qoros "Qamfree" engine. The engine's Swedish designer FreeValve claims that the 1.6-litre (98 cu in) turbocharged engine will produce 170 kW (230 hp) and 320 N⋅m (240 lb⋅ft) of torque. They also claim that, compared to a similar traditional engine, it offers a 50% reduction in size (including a 50-millimetre-lower (2.0 in) height), 30% reduction in weight, 30% improvement in power and torque, 30% improvement in fuel economy, and a 50% reduction in emissions. Christian von Koenigsegg claims in a video that the Qamfree engine with the PHEA camless technology is based on an existing Qoros engine that was "...developed in Germany and Austria five, six years ago...".
Christian von Koenigsegg also claims that the PHEA camless technology allows the elimination of the pre-catalytic converter, because the standard catalytic converter can be brought up to temperature quickly by manipulating the exhaust cycle.
Because camless engines have no camshaft, they may have fewer moving parts. In these systems, the camshaft follower, rocker arms, and/or pushrods have been replaced by an electro-hydraulic actuator system which uses the existing oil pumps, thus reducing development risks of the new system by employing existing technology. Direction changing on older B&W MC engines was engaged by physically changing the direction of the cam roller, whereas with the new camless engine, it is controlled by a computer. This eliminates the risk of mechanical failures that could damage the engine if there was a malfunction while changing directions. Additionally, because there is no chain connection between the crankshaft and the camshaft, the engine is lighter with fewer points of failure. The absence of a camshaft also means that the parasitic load on the engine is lower, which is particularly useful in large marine engines, as it can equate to a large amount of power savings. With a camless engine, fuel injection and exhaust timing are directly controlled by an engine control unit and can be constantly changed and adjusted without stopping the engine. This allows for the engine to run at a lower RPM, a feature useful in ships as it allows better low speed maneuvering while docking. Additionally, when a ship is maneuvering, the computer controlled fuel injection and valve timing allows for faster RPM control, hence faster stopping in emergency situations.
Solenoid valves are used to control valve activation that is electronically operated. These are used for controlling liquid or gas flow and are most commonly used in fluidics as control elements. They are multifunctional in a way to release, shut off, mix, or distribute fluids with high reliability and fast processing. The market for solenoid valves is growing with the imperative growth in all the regions. Increasing application areas year on year and advancement in technology and developed fluid automation technologies, all are driving the market on a global scale.
Conventional mechanical camshaft actuation is capable of generating extremely high forces which, combined with very high stiffness/low mechanical compliance of a conventional modern valve train layout, are used to very accurately and consistently control the position the engine valves. This enables very high levels of valve acceleration and lift and also very small valve-to-valve and valve-to-piston clearances to be used in combination with very high engine speeds. For example, prior to the FIA restrictions, Formula 1 engines ran at speeds of over 20,000 RPM and power outputs of over 330bhp/litre normally aspirated using a conventional camshaft and mechanical valve actuation; it is extremely unlikely that this high engine speed and output can be achieved with camless valve actuation.[citation needed] At 20,000 RPM, the valves open and close 166 times per second.