Unshrouded internally cooled turbine blades

Claim 1

An unshrouded turbine rotor blade of the type which in use is rotatable about a rotor axis and has radially inner and outer ends with respect to said axis; said blade comprising: a tip well formed adjacent the radially outer end of the blade, cooling flow cavity means in said blade which terminate in cooling medium exit means opening into said tip well such that cooling medium flows through said cavity means into said tip well during rotation of said blade, cooling flow deflecting means for deflecting the flow of cooling medium out of said tip well, said cooling flow cavity means, said cooling medium exit means and said cooling flow deflecting means being relatively configured in such a manner that outflows of said cooling medium from said tip well impart reactive forces against said blade in the direction of blade rotation, blade rubbing crown means at the radially outer end of the blade for accommodating rubbing engagement of the blade against a turbine casing means which surrounds the blade in use, and turbine casing means for accommodating the outer end of said blade, wherein said tip well is formed by wall means which extend radially outwardly of a bottom of said tip well and circumferentially surround the contour of the outer end of said blade, wherein said cooling flow deflecting means includes opening means in said wall means which extend over at least a portion of one side of the blade, wherein said blade has a suction side which faces in the general direction of rotation of the blade and a pressure side which faces in the general direction opposite the direction of rotation of the blade, wherein said one side is said pressure side, wherein said wall means includes suction side wall member means which have the radially outer ends thereof bent toward the pressure side of the blade, said opening means being formed Between said radially outer ends of said suction side wall member means and respective radial outer ends of pressure side wall member means forming part of said wall means, and wherein said turbine casing means for accommodating the outer end of said blade includes an annular slot which has a radial depth which is approximately equal to the radial extent of said opening means formed between said suction side wall members and pressure side wall members.