BMW's Valvetronic system in the traditional with gas phase institutions increased on a stick of eccentric shaft, a stepping motor and the middle push rod should parts, the system adopts the stepping motor rotation, again in a series of mechanical transmission is very clever after changed into the size of the valve lift.
As the camshaft operation, CAM will drive push rod and rocker to finish among the valve of opening and closing. When the motor, worm and worm wheel mechanism will first drive partiality axis rotation happen, then the middle push rod and rocker will produce the linkage, eccentric shaft rotation Angle of different, finally the camshaft through the middle push rod and rocker top should become angry from the lift door also will be different. In the motor drive, the valves can realize the lift from 0.18 mm to 9.9 mm of stepless change.
BMW's Valvetronic technology has covered the banner of engines, including current releasing the turbocharged PC. This technology can make the engine for driver intention to make a more rapid feedback, and at the same time through engine management system for precise control of the valve lift, realized the vehicle in the working conditions and the best dynamic matching the load.
BMW, the technology is already very mature, and through the continuous optimization, Valvetronic technology also broke through the speed limit, can be applied in the M-power V8 double turbocharged engine. How to ensure that in the right time make valve lift in the right position is the technology of the biggest difficulty, but it certainly did to engine for more accurate and detailed regulation management.
The Philippines's VVEL system, working principles and BMW's Valvetronic similar, but on the structure is slightly different. VVEL systems use a set of the screw thread and screw combination realized the valve lift continuous adjustable. In the system work, motor through the ECU signal control screw and the relative position of the screw thread, screw the rocker, control of drive component such as rod, and, eventually, to change the size of the valve lift.
Through the control of rocker eccentric stem, and control rod can be in driving motor rotate certain Angle. When the engine at high speed or load, motor drive screw rotation, set in the screw of the screw thread can also have the corresponding lateral movement, and the screw thread of joint structure makes control stem counterclockwise or clockwise rotation happened. Because of the control rod rocker in eccentric, so the rotation center rocker will then rise or fall, so as to achieve the purpose of change valve lift. Although the whole organization look more complex, friction pair is relatively more, but because the system of rocker, control rod and the screw thread is rigid connection, no spring return of mechanism so that the VVEL system even in high speed engine situation also need not consider the problem of inertia.
The Philippines's of the technology, principle and BMW's Valvetronic is very much the same, also is the realization of the power of the engine output make more detailed planning regulation, but this technology is just used in its high-end models of Nissan.
Multiair the greatest characteristic is groundbreaking used electric hydraulic control system to drive the valve timing and lift, although the engine for each cylinder 4 the structure of the valve, but cancelled the intake valve side camshaft, exhaust the camshaft through hydraulic institutions side to drive into the valve.