Numerical Study of Machine Tool Spindle Design with Focus On Blank Dimensional Accuracy

Abstract

This paper examines the potential for a locally made lathe machine to produce machined parts with high and acceptable dimensional accuracy with particular focus on the technical status of the rigidity, vibration, and strength properties of the spindle unit. The spindle unit design is very highly important because this unit actually controls the operations of the lathe machine, therefore the operating performance in obtaining machined products with high precision dimensions is investigated. The models used by Acherkan et al (1973), for rigidity, vibration proof and strength properties were applied in this study. The deflection at the nose of the spindle was found to be 2.0mm, the vibration dimensionless property was determined to be 0.58, and the factor of safety was calculated to be 0.375. These values are at great variance with standard values. They indicate that the spindle unit has been under designed and is capable of producing blanks with marked dimensional inaccuracy. Therefore the spindle unit has been recommended for redesign. The design procedure adopted for this study successfully determined the technical status of the spindle unit.

Keywords: machine tool, rigidity, spindle unit, strength, vibration proof property

Journal of the Nigerian Association of Mathematical Physics, Volume 19 (November, 2011), pp 399 – 404