Journal of Mechanical Engineering and Sciences ISSN (Print): 2289-4659; e-ISSN: 2231-8380 Volume 13, Issue 1, pp. 4704-4717, March 2019 © Universiti Malaysia Pahang, Malaysia DOI: https://doi.org/10.15282/jmes.13.1.2019.25.0395 4704 Design and parametric characterization of flexure bearing as automotive valve spring replacement M. Razali Hanipah 1,2 , Shahin Mansor 1 , M.R.M Akramin 3 and Akhtar Razul Razali 1,4 1 Automotive Engineering Research Group (AERG), Faculty of Mechanical Engineering, Universiti Malaysia Pahang, 26600 Pekan, Pahang, Malaysia * Email: mohdrazali@ump.edu.my 2 Automotive Engineering Centre (AEC), Universiti Malaysia Pahang, 26600 Pekan, Pahang, Malaysia 3 Structural Materials and Degradation Group (SMDG), Faculty of Mechanical Engineering, Universiti Malaysia Pahang, 4 Manufacturing Focus Group (MFG), Faculty of Mechanical Engineering, Universiti Malaysia Pahang, ABSTRACT Automotive valve springs occupy substantial space in the cylinder head of an internal combustion engine and contribute to frictional loss. In this paper, the design and analyses of a flat spring concept, known as flexure bearing are presented. Flexure bearing act like a typical spring which support the shaft but only allow axial displacement, thus reduce the friction of the system. The objective of the research is to design and conduct parametric characterization of flexure bearing for valve spring replacement in a small internal combustion engine. The analyses of flexure bearing strength for different designs, materials and thicknesses were conducted using finite element method. The results show that the maximum stress values are less affected by the material type compared to the number of arms despite a significant difference in young modulus values. The strain values are limited to less than 1% for all materials when the thickness is more than 1mm. The results have provided characteristics for future selection of the flexure bearing in relation to the intended axial displacement. Keywords: Flexure Bearing; Finite Element; Design INTRODUCTION A recent successful trend in passenger vehicles improvement involved fuel economy improvement through start-stop technology [1, 2]. An aggressive approach to reduce fuel consumptions is by improving internal combustion engine efficiency. Valvetrain components design are essential towards an efficient internal combustion engine. One of the component is valve springs, whose stiffness, dimensions and mass are critical for engine operation [3, 4]. In addition, poorly designed valve springs could cause abnormal vibration and hence, noise [5]. Flexure bearing is metal disc with slots cutting that permit flexing in the axial direction while ensuring a higher radial stiffness. Mostly, flexure bearing is used to support