Magnetorheological finishing of ball-cup surface using new tool to enhance ball-transfer-unit performance

ABSTRACT

Ball transfer units (BTUs) are used as an integral part of feed devices and conveyor systems. BTU of stainless steel 304 material is utilized in places with exposure to aggressive ambient conditions. The rough internal hemispherical surface of the blind hole type ball cup (BHBC) of BTU leads to defects such as metal debris generation, vibration, noise, etc. Therefore, fine finishing of the BHBC surface of BTU is highly required for improving their functional performance in industries. To attain the fine-finishing requirement over the interior BHBC work part surface, a new electromagnetic-based magnetorheological hemispherical finishing (MRHF) tool is designed and fabricated with in-process control over the magnetic force. The magnetostatic finite element analysis is conducted over the MRHF tool surface to achieve a higher and uniform magnetic field. Further, optimum parameters are predicted for effective fine-finishing over the interior BHBC work part surface. The roughness value is reduced from 0.310 to 0.070 µm over the interior surface area (981.7 mm²) of the blind hole type ball cup workpiece after 80 min. Also, the enhancement in dimensional accuracy and surface characteristics are achieved. Thus, fine-finishing of the ball cup surface can enhance the functional performance and service life of the BTUs.

KEYWORDS:

• Fine-finishing
• magnetorheological
• polishing
• fluid
• hemispherical
• blind-hole
• ball-cup-surface
• roughness
• ball-transfer-unit

Disclosure statement

No potential conflict of interest was reported by the authors.