Informatics Publishing Limited

Eid S. Mohamed ¹, Saeed A. Albatlan ²

Affiliations
1 Automotive and Tractors Engg., Helwan University, Mataria, Cairo, EG
2 Automotive Engg., Higher Technological Institute, 6th of October City Campus, EG

Abstract

Applying a Continuously Variable Transmission (CVT) in an automotive driveline has several advantages. A CVT can operate at a wider range of transmission ratios, therefore the engine can be operated more efficiently than with a stepped transmission. The present research focuses on the influence of loading conditions on the slip behaviour and torque transmission of the CVT. The CVT model is developed to investigate the range of clamping forces needed to initiate the transmission and to successfully meet the oil pressure requirements. An analytical approach is used to calculate the possible transmission efficiency and traction coefficient of the push belt CVT. The experimental setup and the instrumentation are presented in detail. The measured results are presented in more detail for the V-belt type variator and oil pressure reapplication by a separate hydraulic unit and reduction ratio of CVT.

Keywords

Continuously Variable Transmission, Metal-Push Belt, Slip Characteristics, Clamping Force, Modelling.

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Saeed A. Albatlan ¹, Eid S. Mohamed ²

Affiliations
1 Automotive Engg., Higher Technological Institute, 6th of October City Campus, EG
2 Automotive and Tractors Engg., Helwan University, Mataria, Cairo, EG

Abstract

In modern four-stroke automobile engine technology, variable valve timing and lift control offer potential benefits for making a high performance engine. Variable valve lift (VVL) system for automotive engines is one of the key technologies to attain improvement of fuel economy, power output and reduction of emission. This paper describes an analytical simulation model of the VVL system. The VVL mechanism with a polynomial cam profile is designed to have maximum lift that is greater than the lift of the conventional mechanism. A dynamic model of VVL mechanism with three degrees of freedom is presented. The N42-BMW cylinder head with Valvetronic VVL of internal combustion engine was used in the test set-up. The motored cylinder head test data focuses on VVL system response and evaluation of the developed VVL mechanism. The performance results of a VVL for an overhead camshaft were investigated on the basis of theoretical simulation and experimental data to verify the validity of the VVL system in the test rig.

Keywords

Variable Valve Lift, Dynamic Model, Valvetrain, Engine Valvetronic, Multibody Dynamics, Valve Lift Regulation.

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