Patent ID: 6769163
Filing Date: 2004-08-03
Classification: G01F,Y10T

Abstract:
A method of assembling a Coriolis flowmeter having a flow tube, a connecting ring means, and a tubular balance bar, said method comprising the steps of:extending said flow tube through a center opening in said tubular balance bar; positioning said flow tube so that said flow tube extends through a center opening of said connecting ring means and is coaxial with said balance bar; positioning said connecting ring means so that axial end portions of said balance bar are coaxial with and surround at least a portion of said connecting ring means, the flow tube extending beyond said axial end portion of said balance bar and beyond axial end portions of said connecting ring means; coupling a radial inner circumferential surface of said connecting ring means to said flow tube; a radial outer circumferential surface of said connecting ring means is being tapered in a first direction with decreasing radius with respect to the longitudinal axial center of said flow tube; radial inner circumferential surfaces of said axial end portions of said balance bar having a taper that matches said taper of said connecting ring means; and said balance bar having a greater thermal coefficient of expansion than does said flow tube; placing braze material proximate axial end extremities of junction of said radial outer circumferential surface of said connecting ring means and said inner circumferential surfaces of said axial and portion of said balance bar and junction of surfaces common to said connecting ring means and said flow tube; placing a mass on an end of said flow tube so that said mass exerts force on said connecting ring means thereby urging said connecting ring means axially into engagement with said balance bar, an outer end of said connecting ring means then extending axially beyond an end of said balance bar; heating balance bar, said connecting ring means and said flow tube to brazing temperatures while the mass is exerting the force on the connecting ring; the brazing temperature effective to expand said balance bar radially to enable said connecting ring means to move axially inward within said balance bar, and to permit the braze material to melt and flow in between the junctions of surface; cooling said surface with the braze material in between so that said greater thermal coefficient of expansion of said balance bar generates a radially compressive force against said connecting ring means and said flow tube, thereby brazing said tapered inner circumferential surfaces of said end portion of said balance bar to said tapered outer circumferential surface of said connecting ring means.