GB887158A - Improvements relating to flowmeters - Google Patents

Abstract

887,158. Measuring fluid velocity. GENERAL ELECTRIC CO. Oct. 22, 1959 [Oct. 22, 1958], No. 35830/59. Class 69 (1). A flowmeter has a fluid-accelerating impeller 18, a drive motor 42 for the impeller, a planet gear 88, 92 rotatably carried by the impeller, a resiliently restrained ring gear 94 engaged with the planet gear, and means 64 to sense the movements of the ring gear about its axis. The sun gear 86 is driven from the motor 42 through gearing 44 and magnet assemblies 48, 84 while the ring gear is restrained by a coiled spring 101 and coupled by further magnet assemblies 100, 68 to the means 64 which may be a position telemetering device, such as a synchro. Screws 106 and 110 permit the spring force and zero position of the impeller to be adjusted. Flow straighteners 14 and 16 on either side of the impeller are provided with flow passages 30, 54 and short adjustable vanes 32 to compensate for lack of alignment between the flow passages in the straighteners and the impeller. The ring gear 94 is supported on roller or ballbearings having inner races fixed to a rotating shaft 70 driving the sun gear 86. To eliminate viscosity errors, a cylindrical shroud 128 is provided so that opposite torques due to viscous drag are imposed on the impeller 18 and the supporting member 96 for the ring gear 94. In a modified construction, a disc-like member is mounted on the impeller and adjacent to a plate 82 carrying the magnet assembly 84 so that the viscous drag of the fluid provides an additional driving torque to offset the drag between the outer periphery of the impeller and the meter casing 10. The deflection of the ring gear is measured by a strain gauge. Fluid flow may take place in either direction in both constructions.