An Optimum Flexible Linkage Design of a Fully Variable Electromechanical Valve Actuation System for Internal Combustion Engines

2011 ◽  
Vol 133 (12) ◽  
Author(s):  
D. T. Hossein Rokni ◽  
Rudolf J. Seethaler ◽  
Abbas S. Milani
Keyword(s):  
Internal Combustion Engines ◽  
Mechanical Design ◽  
Design Procedure ◽  
Experimental Tests ◽  
Internal Combustion ◽  
Combustion Engines ◽  
Connecting Rod ◽  
Actuation System ◽  
Flexible Linkage ◽  
Valve Actuation

In this study, the mechanical design of a fully flexible valve actuation system (FFVA) for intake valves of naturally aspirated internal combustion engines is optimized. The original FFVA design used a connecting rod in order to transform the rotating motion of the actuator to translating motion of the valve. In the improved design introduced here, the connecting rod is replaced by a flexible linkage. This step is taken in order to eliminate wear and play in the mechanical connections. A detailed design procedure is presented to optimize the heavy fatigue load on this element. Simulations and experimental tests are carried out in order to validate the system performance. It is shown that valve trajectory and energy consumption of the actuation system obtained by simulations are consistent with those observed experimentally. The present redesigned FFVA system then provides more reliable valve motion than previously shown designs.

Improved Mechanical Design for a Fully Variable Electromechanical Valve Actuation System for Internal Combustion Engines

2010 ◽  
Author(s):  
Hossein Rokni Damavandi Taher ◽  
Rudolf J. Seethaler ◽  
Abbas S. Milani
Keyword(s):  
Internal Combustion Engines ◽  
Mechanical Design ◽  
Experimental Tests ◽  
Internal Combustion ◽  
Combustion Engines ◽  
Mechanical Vibrations ◽  
Actuation System ◽  
Ohmic Losses ◽  
Valve Motion ◽  
Valve Actuation

This study aims to improve the mechanical design of a fully flexible valve actuation system (FFVA) for intake valves of internal combustion engines. Optimization procedures for increasing the reliability and efficiency of the mechanical design of the FFVA system are presented. Simulations and experimental tests are carried out in order to validate the system performance. It is shown that position, velocity and acceleration of the valve obtained by simulations are consistent with those observed experimentally. Furthermore, it is observed that the mechanical vibrations are considerably reduced in the redesigned FFVA system. As a result, current levels and ohmic losses in the electric motor are also reduced. The present redesigned FFVA system then provides more reliable valve motion and better efficiency than the previously shown design [25].

A Cogging Torque Assisted Motor Driven Valve Actuation System for Internal Combustion Engines

2013 ◽  
Author(s):  
Bradley A. Reinholz ◽  
Rudolf J. Seethaler
Keyword(s):  
Internal Combustion Engines ◽  
High Efficiency ◽  
Acoustic Emissions ◽  
Internal Combustion ◽  
Performance Criteria ◽  
Combustion Engines ◽  
Cogging Torque ◽  
Actuation System ◽  
Stringent Performance ◽  
Valve Actuation

Electromechanical valve actuation (EVA) for internal combustion engines promises to significantly improve engine efficiency and lower emissions by reducing pumping losses and allowing for novel combustion strategies. However, current designs have not been able to meet the stringent performance criteria for reliability, efficiency, acoustic emissions, weight, and cost that are required by the automotive industry. This paper describes a novel cogging torque assisted motor driven (CTAMD) valve actuation system that promises to meet both the performance and robustness requirements. In contrary to existing EVA systems that recover the kinetic valve energy using a mechanical spring system, the CTAMD system recovers kinetic energy in a magnetic field. This allows for high efficiency while maintaining a simple and elegant electromechanical design. This paper describes the characteristics of CTAMD systems and outlines an electromechanical design for such a system. Then computer simulations of the proposed design are used to demonstrate the expected performance of the system. Finally, the simulated results are compared to other EVA systems to highlight the anticipated improvements.

scholarly journals The influence of centrial forces on crankshaft bearing lubrication is in emergency modes of the engine of the car

2021 ◽  
Vol 12 (2) ◽  
pp. 112-121
Author(s):  
Oleksandr Khrulev ◽  
◽  
Olexii Saraiev ◽  
Iryna Saraieva ◽  
◽  
...  
Keyword(s):  
Internal Combustion Engines ◽  
Operating Mode ◽  
Internal Combustion ◽  
Technical Condition ◽  
Operating Conditions ◽  
Combustion Engines ◽  
Connecting Rod ◽  
Oil Supply ◽  
Technical Expert ◽  
The Difference

The analysis of the crankshaft bearing condition of the automotive internal combustion engines in the case of insufficiency and breakage of oil supply to them is carried out. It is noted that this fault is one of the most common causes of damage to rubbing pairs in operation. At the same time, the different groups of bearings are often damaged, which cannot be explained within the framework of existing models of plain bearing lubrication. The objective of the work is to develop a mathematical model of oil supply to connecting rod bearings in emergency mode, taking into account the characteristic features of the bearing design. The model also, depending on the nature of the damage, should help to determine and explain the causes of bearing failures if they occur in different modes when operating conditions are broken. A computational model has been developed that makes it possible to assess the effect of design differences in the features of oil supply and the action of the centrifugal forces during crankshaft rotation on the oil column in the lubrication hole where oil is supplied to the conrod bearing. Calculations of the change in time of the oil supply pressure to the connecting rod bearings for the various designs of the crankshaft lubrication holes have been performed. It is shown that, depending on the operating mode of the engine and its design, the oil pressure in front of the connecting rod bearings does not disappear immediately after oil supply failure to crankshaft. Moreover, the lower the crankshaft speed is, the longer the lubrication of the conrod bearings will continue. The calculation results are confirmed by the data of the expert studies of the engine technical condition, in which the crankshaft was wedged in the damaged main bearings was found in the absence of serious damage to the connecting rod ones. It has been found that such features of the damage correspond to an rapid breakage of the oil supply to the crankshaft in the case of such operational damage as the oil pump and pressure reducing valve failure, the oil filter seal and oil pan destruction, etc. The developed model explains the difference in lubrication conditions and in the damage feature to the main and connecting rod bearings in the emergency cases of the oil supply breakage, which are observed during operation, and helps to clarify the failure causes. This makes it possible to use the model and the obtained data when providing auto technical expert studies of the failure causes of automobile internal combustion engines This makes it possible to use the model and the obtained data when providing auto technical expert studies of the failure causes of automobile internal combustion engines when the operating conditions are broken.

scholarly journals SOME ASPECTS OF INFLUENCE OF THE CONNECTING ROD DESIGN ON THE OUTPUT PARAMETERS OF HIGH-SPEED INTERNAL COMBUSTION ENGINES

2020 ◽  
Vol 0 (1(86)) ◽  
Author(s):  
Сергій Олексійович Дмитрієв ◽  
Олександр Едуардович Хрулєв
Keyword(s):  
High Speed ◽  
Internal Combustion Engines ◽  
Internal Combustion ◽  
Combustion Engines ◽  
Connecting Rod

A Continuously Variable Poppet Valve Actuator for Internal Combustion Engines

1986 ◽  
Vol 200 (3) ◽  
pp. 187-195 ◽  
Author(s):  
S J Charlton ◽  
M Shafie-Pour
Keyword(s):  
Internal Combustion Engines ◽  
Internal Combustion ◽  
Combustion Engines ◽  
Finite Element Program ◽  
Rigid Body Dynamic ◽  
Poppet Valve ◽  
Actuation System ◽  
Valve Motion ◽  
Element Program ◽  
Body Dynamic

The paper describes a continuously variable poppet valve actuation system which may be applied to internal combustion engines to render the valve motion controllable while the engine is running. The first phase of a programme to develop the device is described. The results of a rigid-body dynamic analysis are presented followed by a dynamic simulation of the mechanism using a proprietary finite element program. These give an insight into its operation and clarify some of the problems to be solved if the device is to be successfully applied.

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