| 摘要 |
1,139,840. Rotary fluid-flow meters. ROCKWELL MFG. CO. Jan. 6, 1967 [Jan. 20, 1966], No. 917/67. Heading F1F. [Also in Division H2] In a rotary fluid-flow meter comprising a bladed rotor 90, Fig. 1, rotatably supported in a tubular cylindrical housing 22 and driven by liquid flowing through the housing along a path parallel to the rotor axis, a shaft 160 driving a register 130 extends radially through the housing and is driven by a magnetic coupling which comprises drive and driven permanent magnets 134, 138 carried by the rotor 90 and shaft 160 respectively and a fixed non-permanently magnetizable flux keeper unit 139 defining a magnetic flux path between the magnets. The magnets 134, 138 are of ceramic material and annular with the former snugly fitting a recess 144 formed in the rotor hub and the latter fixed to the shaft 160. The flux keeper unit 139, Fig. 8, made of soft iron is of horse-shoe shape initially machined in one piece having a flat plate section 181, and three keeper sections 182, 183, 184 extending therefrom spaced 120 degrees apart and fitting in respective recesses in a support plate 64. The keeper is then embedded in a suitable non-magnetic potting compound 188 which is allowed to harden before the assembly is drilled at 176 to provide three spaced apart polefaces 192, 193, 194 surrounding the magnet 138. Magnet 134 having a North pole and a South pole 180 degrees apart interacts with polefaces 196, 197, 198 on the keeper sections 182, 183, 184 to produce a magnetic field at polefaces 192, 193, 194 which rotates the magnet 138. The rotor 90 together with a core 32 on which it is cantilever mounted, are mounted in a tubular shroud 42 which is suspended from a detachable cover 48 of the housing to form a unit with the register 130 so that the whole may be removed from the housing for servicing or replacement of parts without disturbing the flanged joints connecting the housing 22 to the pipe-line. The rotor is preferably made of polypropylene and its blades 92 are flat and set at an acute angle with respect to the flow path. A calibrating vane 120 secured to the cover 48 by a shaft 122 is factory adjusted. The rotor shaft 70 rotates in graphite bearings 96, 98. |
