The invention relates to a flow sensor of a
heat energy meter, which is characterized in that a rolling bearing is fixed in an
impeller hole to form an
impeller component together with the middle part of a shaft; two sleeves are arranged on two sides of the shaft of the
impeller component and the rolling bearing, the impeller component is arranged in a groove of an impeller seat, and two eddy plates and bolts compact the shaft of the impeller component to form a
machine core; a sealing ring and the
machine core are arranged in a shell hole, and the
machine core is compacted by a gland bush and bolts; and a
magneto-electric converter is arranged in an upper hole of the gland bush, a
magnetic shield is fixed outside the shell by using bolts, and the bottom of the shell is provided with a
sewage outlet. By using the flow sensor of the
heat energy meter, the hot water
stream acts on an impeller vane in the tangential direction, the impeller generates revolution to perform flow measurement, and a permanent
magnet material magnetic element is used for indicating the flow, the
magnetic shield and the
sewage outlet are arranged outside the shell, and the hot water flows through the shell directly, thus the low sensor of the
heat energy meter has the characteristics of long service life, convenient
pollution discharge, reliable performance, small hot
water pressure loss, good flow capacity, wide flow range ratio, small appearance volume, low manufacturing cost and the like.