| 摘要 |
968,195. Rotary pumps and motors. JAMES HOWDEN & CO. Ltd. Aug. 21, 1961 [Aug. 30, 1960], No. 29920/60. Heading F1F. In a rotary compressor or engine of the type comprising two or more rotors formed with intermeshing helical grooves and threads, the root and tip diameters of either or both rotors are gradually reduced from end to end of the rotor to provide tapered clearances, which compensates for the temperature gradient in use-so that, in operation, optimum working clearances for maximum efficiency are provided at all points along the length of the rotors. In Fig. 1 the tip diameter is gradually reduced from x at the inlet to x<SP>1</SP> at the outlet end and the root diameter similarly from y to y<SP>1</SP> to produce equal tapers t. Figs. 3 and 4 show female and male rotors having a 6 to 4 land combination, in which the full lines indicate the grooves and lobes at the inlet ends of the rotors and the chain-dotted lines the grooves and lobes at the outlet ends. The lobes of the male rotor and the grooves of the female rotor have the-same radii R which are constant along the lengths of the rotors but are on decreasing pitch circle diameters. In a modification (Figs. 5, 6, not shown) to provide the taper the radius of the male rotor lobes decreases going from inlet to outlet, and that of the female rotor grooves increases in the same direction. Specification 627,162 is referred to. |
