| 摘要 |
<p>1309516 Rotary flowmeters ITT INDUSTRIES Inc 19 April 1971 [25 Feb 1970J 22024/71 Heading F1F A reversible rotary flowmeter having a vaned rotor 12 mounted with limited axial play on a shaft 20 includes on each side of the rotor a cup-shaped diffuser 23, 24 having a radial lip 34, 36 to deflect fluid away from the upstream side of the rotor hub 28, the reduced pressure causing a flow of fluid through a passage 37 from the downstream side of the rotor to provide axial balancing of the rotor. The shaft 20 is secured to a pair of spiders 13, 14 each comprising three or four spring steel cylinders 15, 17, and a spacer 27 separates the diffusers 23, 24. At very low flow rates the high drag on the rotor causes it to bear against the downstream diffuser, but as the flow increases, the rotor moves towards the upstream diffuser due to the low pressure on the upstream side of the rotor hub, the angular acceleration imparted to the fluid flowing through the passage 37 placing a drag on the rotor. At high flow rates, the rotor approaches the upstream diffuser and a throttling effect reduces the flow through the passage 37 thus reduces the drag. The overall effect is to increase the effective range of the meter at both low and high flow rates. In a second embodiment, the rotor hub is formed integrally with a pair of stub shafts located in bearing recesses in the diffusers.</p> |
