摘要 |
A turbine (4) suitable for use in down-hole drilling and the like, and comprising a tubular casing (11) enclosing a chamber (18) having rotatably mounted therein a rotor (19). The rotor (19) comprises at least one turbine wheel blade arrays (30a) with an annular array of angularly distributed blades (30), and a generally axially extending inner drive fluid passage (14) generally radially inwardly of said rotor (19). The casing (11) also has respective generally axially extending outer drive fluid passage (16) associated with said at least one turbine wheel blade array (30a), and one of the inner and the outer drive fluid passages (14, 16) constitute a drive fluid supply passage and is provided with outlet nozzles (17) formed and arranged for directing at least one jet of drive fluid onto the blade drive fluid receiving faces (31) for imparting rotary drive to said rotor (19). The other of the inner and the outer drive fluid passages (14, 16) constitutes a drive fluid exhaust passage and is provided with exhaust aperture (28) for exhausting drive fluid from the turbine (4). |