| 摘要 |
<p>A rotary positive-displacement machine of the type having intermeshing lobed rotors, comprising first and second two-lobed rotors (22,24) mounted respectively in the two housing bores (14,16) for synchronous rotation. The first, valve rotor (22) has a hub portion which periodically occludes an outlet port (20) to control the generation and discharge of high pressure fluid from the housing (12). Each lobe (32) of the valve rotor (22) has a leading tip portion (34) which is radiussed so that it does not define a sharp edge. Each lobe (32) also has an outer flank, a major portion (1-2) of which is a convex curve, which is generated to correspond to the form of the tip (8-9) of the second, displacement rotor (24) and which merges with a convex arcuate portion (2-3) whose centre (38) is offset from the valve rotor axis (26). Furthermore, each lobe (32) has a trailing flank formed by a convex curve (4-5), generated to correspond to the form of the tip (8-9) of the displacement rotor (24), which merges with a convex arcuate portion (5-6), whose centre (42) is offset from the valve rotor axis (26), followed directly by a concave arcuate portion (6-7) whose centre (44) is also offset from the valve rotor axis (26). <IMAGE> <IMAGE></p> |
