PROPORTIONING GEAR-TYPE PUMP

FIELD: mechanical engineering. ^ SUBSTANCE: invention is designed for delivering and metering out spinning solutions of highly corrosive polymers in machines for forming acetate, viscose, para-aramyde and other fiber. Proposed proportioning gear-type pump has cast iron housing with solution inlet and outlet channels, drive shaft, gear mechanism with stator, upper and lower covers, driving gear installed on drive shaft, driven gear installed on axle with hole in suction zone communicating with solution inlet channel and hole in delivery zone communicating with solution outlet channel. Three-layer coating playing the part of bearing is applied to drive shaft in shaft-housing friction zone. Composition of said coating is as follows: first layer - polyimide varnish - 90 weight parts + alumochromium phosphate binder - Io weight parts; second layer - pure poluimide varnish - 100 weight parts, and third layer - polyimide varnish - 90 weight parts + colloidal graphite - 8 weight parts + lecithin - 2 weight parts. Clearance between surface of housing and surface of coating is from 0.6 to 0.9 of thickness of first layer whose thickness is from 9 mcm to 10 mcm which is provided by precision polishing of coating. Ratio of thickness of first layer to thickness of second and their layers is 1 to 2 and 1 to 3, accordingly. ^ EFFECT: increased service life of proportioning gear-type pump. ^ 2 dwg