... The metering chamber is composed of core rack, impeller, worm wheel and worm. The main body is composed of meter shell, oil ... rotate. The rotation speed of impeller will be reduced by worm wheel, worm and gear, and driven by the magnetic coupler, the ... . Impeller5. zero-resetting 6. accumulation instructs 7. Magnetic coupler8. Worm wheel9. Valve mechanism10. Oil outlet pipe11. Bending handle12. Gun13. ...