Investigation on laser beam machining of miniature gears

Abstract

Abstract: Micro‐machining has become a fast growing field in the global manufacturing sector due to increasing demand of miniature machines and devices. The trend involves the fabrication of precision miniature parts that have widespread applications in many areas such as, electronics, biomedical, aerospace, robotics, automobiles and consumer products. Miniature gears are essential components of miniaturised devices such as miniature motors and pumps, scientific instruments, medical equipment, timing devices, and robots etc. These gears are generally fine‐pitched gears running at very high speed, mainly used for transmission of motion and/or torque. Therefore, minimum running noise, accurate motion transfer and long service life are the required qualities of these gears. Considering that a laser beam is capable of cutting complex shapes with great precision and little waste, motivates its use to machine small sized parts including miniature gears. This article reports on the fabrication of stainless steel miniature gears by laser beam machining (LBM) process. A total of twenty experiments have been conducted following one factor at a time design of experiment strategy on CO2 laser machine. The fabricated gears have 9 mm pitch diameter, 10 teeth, and 4.5 mm thickness. The effects of laser machining parameters on surface roughness (mainly average roughness ‘Ra’ and mean roughness depth ‘Rz’) of gears have been analysed. The best quality miniature gear fabricated by LBM possesses 1.04 μm average roughness and 5.797 μm mean roughness depth at par with that obtained by conventional and other advanced processes of miniature gear manufacturing. Investigation reveals that LBM is capable to produce miniature gears of good surface finish and integrity ensuring their high functional performance and long service life. The outputs of this preliminary work encourage further exploration of LBM to establish it as an alternative process for fabrication of precision miniature gears