Fully variable intake valve system

Fully variable intake valve system

◆ BMW Valvetronic is a valve drive system with a fully variable intake valve lift control function. The engine output is controlled by a stepless variable intake valve lift, which no longer requires the throttle valve that was necessary for gasoline engines in the past. This intake valve lift function keeps power loss extremely low by controlling the amount of air drawn into the engine. In the actual driving process, Valvetronic electronic valve technology brings higher fuel economy, lower exhaust emissions, better response and higher level of smooth running.

◆ The BMW Valvetronic system adds components such as an eccentric shaft, a stepping motor and an intermediate push rod to the traditional valve timing mechanism. The system subtly changes the lift of the intake valve after a series of mechanical transmissions through the rotation of the stepping motor.

◆ When the camshaft is running, the cam will drive the middle push rod and rocker arm to complete the opening and closing of the valve. When the motor is working, the worm gear mechanism will first drive the eccentric shaft to rotate, and then the middle push rod and the rocker arm will be linked. The angle at which the eccentric shaft rotates is different, and finally the lift produced by the camshaft through the middle push rod and the rocker arm to push the valve will also be different. Driven by the electric motor, the lift of the intake valve can be changed steplessly from 0.18 to 9.9mm.