Patent ID: 7168328

Claim:
An apparatus for measuring a flow rate of a mass flow of bulk material, said apparatus comprising an impeller wheel ( 2 ) in a housing ( 1 ), a drive shaft ( 3 ) for supporting and driving said impeller wheel ( 2 ) with a constant rpm in said housing, whereby said mass flow admitted to said impeller wheel is deflected and a radial and tangential velocity component is imposed on said mass flow, said apparatus further comprising a drive spur gear wheel ( 11 ) secured to said drive shaft ( 3 ), an intermediate spur gear wheel ( 21 ) meshing with said drive spur gear wheel ( 11 ), a further drive spur gear wheel ( 20 , 31 ) meshing with said intermediate spur gear wheel ( 21 ), a force measuring device ( 26 ) holding the intermediate spur wheel in place, a support sleeve ( 4 ) coaxially surrounding said drive shaft ( 3 ), said support sleeve reaching into said housing ( 1 ) of said impeller wheel ( 2 ), said apparatus further comprising separate drive means ( 19 , 32 ) for rotating said support sleeve ( 4 ) with an rpm corresponding to said constant rpm of said drive shaft ( 3 ), and a stationary housing section ( 5 ) wherein said support sleeve ( 4 ) is rotatably mounted.