| 摘要 |
An impeller 24a,24b for carrying diametrically extending blades (28, Fig 1) of a driven-vane flowmeter is metallically sealed axially and radially in a housing (10) by at least one raised portion 38, in the form of radial web which extends axially on the outer circumference of the impeller 24b and which seals against a wall (22) of the housing (10), and/or by at least one a radially extending portion 32,34 defined between adjacent sectors or segments of sunk surfaces (shaded dark in Fig 2) formed in an end face of the rotor 24a and which seals against an end lid of the housing (10). In use, any impurities carried in the fluid will move from between sealing surfaces of the impeller 24a,24b and the housing (10) and will collect in the gap regions between the sealing surfaces, minimising potential leakage through damaged sealing surfaces and consequential loss in flow measurement accuracy. Bores 32' extend axially through the impeller. |
