Performance and power consumption optimization of a hydraulic variable valve actuation system

Actuation System ◽

Return Spring ◽

Valve Opening ◽

System Robustness ◽

Variable Valve ◽

In this paper, a new hydraulic variable valve actuation system is proposed. Using this system, the engine valve opening and closing timings and lift are flexibly controlled with two rotary spool valves actuated by the engine crankshaft. High degree of flexibility with less control complexity and high repeatability are the advantages of this system over other camless valvetrains; however, in this system, there is a trade-off between its robustness and power consumption. A numerical model of the system is developed to study the system functionality at different operating conditions. To validate the developed model, the simulation results for a random operating condition are compared with those from the experiments. A sensitivity analysis is done to study the effects of variations in different design parameters on system robustness and power consumption. The results prove that increasing engine valve return-spring stiffness and actuator piston area will reduce the mechanism sensitivity to engine cycle-to-cycle variations; however, this results in poor energy efficiency. Therefore, a neat energy recovery strategy is developed to recuperate a portion of the energy used to compress the engine valve return-spring during valve opening interval. The results show that more than 90% of the extra energy wasted for the sake of system robustness could be regenerated through the proposed energy recovery system.

Design of brushless DC motor for variable valve actuation system of gasoline engine

2013 International Conference on Electrical Machines and Systems (ICEMS) ◽

10.1109/icems.2013.6713353 ◽

2013 ◽

Author(s):

Jung-Moo Seo ◽

Jun-Hyuk Choi ◽

In-Soung Jung ◽

Hyun-Kyo Jung

Keyword(s):

Gasoline Engine ◽

Dc Motor ◽

Brushless Dc Motor ◽

Brushless Dc ◽

Actuation System ◽

Variable Valve ◽

Electro-pneumatic variable valve actuation system for camless engine: Part II-fuel consumption improvement through un-throttled operation

Energy ◽

10.1016/j.energy.2019.116741 ◽

2020 ◽

Vol 193 ◽

pp. 116741

Author(s):

Srinibas Tripathy ◽

Abhimanyu Das ◽

Dhananjay Kumar Srivastava

Keyword(s):

Fuel Consumption ◽

Actuation System ◽

Engine Part ◽

Camless Engine ◽

Variable Valve ◽

Fuel Consumption Improvement ◽

Volume 3: Advanced Composite Materials and Processing; Robotics; Information Management and PLM; Design Engineering ◽

Design of a New Mechanical Variable Valve Actuation System for Motorcycle Engines

10.1115/esda2012-82317 ◽

2012 ◽

Cited By ~ 2

Author(s):

Carmelina Abagnale ◽

Mariano Migliaccio ◽

Ottavio Pennacchia

Keyword(s):

High Performance ◽

Numerical Procedure ◽

Valve Lift ◽

Actuation System ◽

Mechanical Variable ◽

System 2 ◽

Variable Valve ◽

System 1 ◽

This paper deals with design and manufacturing of a mechanical variable valve actuation (VVA) system, developed as part of a MUR financed research project concerning the realization of a high performance motorcycle engine, through a partnership of Moto Morini (Bologna), Dell’Orto (Milano), Istituto Motori - CNR (Napoli) and DiME (Department of Mechanical Engineering and Energetics) – University of Napoli Federico II. After a synthetic description of the main variable valve actuation methods currently employed, the paper presents the results of our mechanical VVA system, consisting of three main elements: cam, main rocker arm with fixed fulcrum and secondary rocker arm with mobile fulcrum. This VVA system (system 1) enables valve lift variation by a simple translation of one of the three elements (the intermediate one). The study has been conducted implementing a numerical procedure specifically designed to determine cam profile and kinematic and dynamic characteristics of the whole system, starting from the following input data: rocker arm geometry, relative positions and inertial data of elements, spring stiffness and preloading, camshaft speed and valve lift law. The model has been validated against the conventional timing system using kinematic simulations. Results of the numerical procedure verify the validity of the VVA system, capable of a valve lift variation, with a limited acceleration. Starting from the numerical results, we have developed a new mechanical variable valve actuation system (system 2): it consists of the same three elements used previously, but they are connected in a different way. The newer system enables more general lift profile distributions with a similar geometric complexity. The activity has been extended to research for a new solution (always a mechanical system), capable to allow inlet valves complete closing and timing and duration variation (system 3). This paper reports results reachable with the simplest system 1, that gives better perspectives of use for a new two-wheel vehicle engine.