Hydraulic Variable Valve Timing Testing and Validation

Variable Valve Timing;Hydraulic Valve Timing;Valve lift control;Valve timing control;Engine Valvetrain;Variable Valve Actuation;Phase Shifting

Chermesnok, Matthew

University of Waterloo

关键词: Variable Valve Timing;    Hydraulic Valve Timing;    Valve lift control;    Valve timing control;    Engine Valvetrain;    Variable Valve Actuation;    Phase Shifting;   

Others  :  https://uwspace.uwaterloo.ca/bitstream/10012/10572/1/Chermesnok_Matthew.pdf

瑞士|英语

来源: UWSPACE Waterloo Institutional Repository

【 摘 要 】

This thesis documents the development of a fully continuous, hydraulics-based variablevalve timing system. This hydraulics based variable valve timing system is capable ofcontrolling an engine valves lift height and infinitely varying the engine valves lift profile.Along with full valve controllability during normal operation, the variable valve timingsystem is capable of providing the same operation as a classic cam shaft under enginepower loss conditions. This is possible due to the rotating hydraulic spool valves coupled tothe engines crank shaft, which are used to actuate the engine poppet valves.The main focus of this thesis is to investigate, alter and implement a new iteration of thehydraulic variable valve timing system on a standalone test bench to validate the systemsoperating principles. The test bench utilizes servo motors to act as an engines crank shaftwhich runs the rotating hydraulic spool valves and hydraulic pump. This serves as anintermediate step to full engine implementation of the variable valve timing system.The research begins by analyzing the current mechanical spool valve and hydraulic cylinderdesign for any potential problems that may occur either during assembly or full operation.The basic system equations are presented to give a glimpse into the working principles ofthe rotary valves. The mechanical, electrical, and hydraulic subsystems are discussed interms of what was considered during the design and implementation process. Then designchanges that were performed on the rotary valve system to overcome any failures. Lastlythe resulting data is presented from the current variable valve timing design to verify propersystem functionality.