Jitendra Sharad Narkhede1, Dr. Kishor B. Waghulde2

1(ME Student, Department of Mechanical Engineering, J. T. Mahajan College of Engineering, Faizpur (NMU), Maharashtra, India)

2(Professor, Department of Mechanical Engineering, J. T. Mahajan College of Engineering, Faizpur (NMU), Maharashtra, India)

Introduction

Magnetic couplings are devices used to transmit torque from a primary driver to a load without mechanical contact. They are ideal for isolated systems, offering advantages like self-protection against overload (pull-out torque) and tolerance to shaft misalignment. This paper explores the axial force and pull-out torque in disc-type permanent magnetic couplings under steady state, utilizing rare-earth magnets.

Traditional couplings requiring mechanical contact often lead to noise, dust, and maintenance. In contrast, magnetic couplings facilitate contact-free torque transmission, making them advantageous in industrial applications, including vacuums and high-pressure vessels. The axial permanent magnetic couplings (APMCs) discussed in this study consist of two discs with sector-shaped permanent magnets arranged alternately with north and south poles, separated by an air gap. The study evaluates these couplings’ geometrical features and torque characteristics.

Abstract

This paper presents an analysis of the pull-out torque and axial force of a disc-type permanent magnetic coupling under steady-state conditions. Rare-earth permanent magnets are utilized, with torque and force measured by altering the air gap between discs and assessing geometrical parameters. Results show that increasing the air gap length decreases pull-out torque and axial force. Experimental analysis results are validated through prototype measurements.

Keywords:

Pull-out torque, Disc type magnetic coupling, Axial force, Analytical Model, Permanent magnets