The invention provides a
helical vane type water meter, and belongs to the technical field of water meters. The partition plate is arranged in the water inlet cavity of the flow channel of the shell and located on the side far away from the water inlet,
water flow entering the water inlet cavity can be blocked at the far end, the turbulent flow influence caused by direct
impact of the
water flow is avoided, the monitoring precision is improved, and meanwhile, the
water flow is prevented from entering the water inlet cavity. The
impeller assembly is rotationally installed in the fluid director which is formed by directly connecting and combining the upper fluid guiding part and the lower fluid guiding part, so that the structure for supporting the
impeller assembly is simpler, the number of structures needing to be matched with each other is small, the problem that the two ends of a rotating shaft of an integrated
impeller are not coaxial due to
machining and assembling precision is solved, structural errors are reduced, and the
machining efficiency is improved. Besides, one end of the rotating shaft of the integrated impeller extends out of the fluid director and then is provided with a
magnet, the
magnet is isolated from water flow, the problem that the
magnet is interfered by impurities such as
rust existing in the water flow is avoided, the monitoring precision of the water meter is further improved, and the service life is prolonged.