Versatility in Fixture Design to Accommodate Different Steam Turbine Casing as Each Projective Tailor Made

Abstract

A fixture is a special tool used to accurately and stably locate the workpiece during machining process. Proper fixture design improves the quality and production of parts and also facilitates the interchangeability of parts that is prevalent in much of modern manufacturing. Fixtures are used to locate and constrain a workpiece during a machining operation. A machining fixture has two basic functions are to locate the component to a right position in relation to cutting tools and to hold the component tightly so that it will not move during the machining operation. Lack of rigidity causes vibration which is very dangerous.

In the present study an attempt has been carried out to make universal type of fixture which is capable to handle different steam turbine casing having geometry changing attributes. Modeling has been carried out of existing fixture using Pro- E software. Based on the available data of existing fixture, calculation of forces, vibration, control points and analysis were carried out in ANSYS software.

Result of analysis shows the high vibration and stresses are produced in existing fixture. Based on analysis, modifications in structure is carried out by adding more number of truss member which is capable to fix various steam turbine casings having geometry changing attributes and have capability to tilt component at required degree for machining application.