Stress Analysis of the Adhesive Used in a Hard Disk Drive Bearing Assembly Using Finite Element Model

Abstract

The objective of this work is to determine the strength of the adhesive injected into the gap between the bearing and actuator arm surfaces under changes of nozzle position on the X and Y axis from the reference position using a finite element model. In this study, maximum stress and maximum shearing stress are used to indicate the adhesive strength. The minimum safety factor then is calculated to show the ratio of the yield strength to the maximum strength. The volume fraction is used to estimate the amount of adhesive on both parts of the bearing assembly. The result show, the maximum stress and strain peak for the case (0.25, 0.2) mm, σmax= 554.4 MPa, τmax= 319.6 MPa and Sfmin= 0.10. Setting the nozzle position to coordinates (0.2, 0.3) mm gave the lowest stress, σmax= 69.0 MPa, τmax= 39.2 MPa and Sfmin= 0.63. The nozzle position significantly affects the adhesive strength. If the nozzle is moved closer to the actuator arm, the stress distribution is better than placing the nozzle near the bearing. Therefore the suitable position for injection is (0.20, 0.30) mm, while the worst poor position is (0.25, 0.2) mm.