Turbines and in particular pelton wheel turbines

Abstract

A turbine rotor (eg: a Pelton wheel) is described which comprises a plurality of individual radial body members ( 11 ) comprising one or more impeller elements (eg: buckets) ( 1 ). The radial body members comprises segments which have leading ( 13 ) and trailing ( 15 ) radial abutment surfaces that contact with the respective radial abutment surfaces of adjacent radial body members when assembled as a unit. Each radial body member comprises at least one further abutment ( 21 ), preferably two at opposite axial ends ( 17,19 ) thereof, and locating means ( 26,27 ) is provided which co-operates with the further abutment means, preferably directly. Wedging means which is tapered in the radial direction relative to the axis of rotation of the turbine rotor, acts between the radial body members and the locating means, and means is provided which acts via said wedging means to draw the radial body members radially inwards to hold them together as a unit. More particularly the locating means comprises two collars ( 26,27 ) which are engageable with a respective one of the axial end abutments ( 21 ) of the radial body members, and the wedging means comprises frusto conical formations of the further abutments of the radial body members and the locating means. The means acting via the wedging means to draw the body members radially inwards comprises axial clamping means ( 35 ) operable between the two collars and/or taper action locating means ( 34,38 ) securing the two collars to a connecting shaft or axle element ( 6 ).

1 . A turbine rotor having an axis of rotation and comprising an axle element, and a plurality of individual radial body members carrying one or more impeller elements, and wherein the plurality of radial body members are secured with respect to said axle element, each radial body member having leading and trailing radial abutment surfaces relative to the direction of rotation of the rotor that contact with the respective radial abutment surfaces of adjacent radial body members, and each radial body member further comprising at least one further abutment means, and the turbine rotor further comprising locating means in one of direct and indirect engagement with the further abutment means of the radial body members, and wedging means which is tapered in the radial direction relative to the axis of rotation and which acts between said abutment means and said locating means, and further comprising means acting via said wedging means to draw the radial body members radially inwards resisted only by contact of the respective adjacent leading and trailing radial abutment surfaces of the body members to hold them together as a unit.  
     
     
         2 . A turbine rotor as claimed in  claim 1  to which the radial body member is common to a plurality of radially disposed impeller elements.  
     
     
         3 . A turbine rotor as claimed in  claim 2  in which the plurality of impeller elements are formed integrally with the associated radial body member  
     
     
         4 . A turbine rotor as claimed in  claim 2  in which the plurality of impeller elements are discrete members that are secured to the body member by positive fixing means.  
     
     
         5 . A turbine rotor as claimed in  claim 1  in which each impeller element is formed with its own radial body member.  
     
     
         6 . A turbine rotor as claimed in  claim 1  in which the body members form segments of the rotor and the leading and trailing radial abutment surfaces thereof are tapered so that they converge on and intersect at the axis of rotation.  
     
     
         7 . A turbine rotor as claimed in  claim 1  in which the further abutment means comprises axial abutments means.  
     
     
         8 . A turbine rotor as claimed in  claim 1  in which each radial body member comprises two of said further abutment means which are disposed to opposite axial ends thereof.  
     
     
         9 . A turbine rotor as claimed in  claim 8  in which the locating means comprises two locating elements that are engageable with a respective one of the two further abutment means of the radial body members.  
     
     
         10 . A turbine rotor as claimed in  claim 1  in which the wedging means comprise at least one separate member interposed between the further abutment means and the locating means.  
     
     
         11 . A turbine rotor as claimed in  claim 1  in which the wedging means is incorporated in at least one of the further abutment means of each of the radial body members and said locating means.  
     
     
         12 . A turbine rotor as claimed in  claim 1  in which said at least one locating means comprises an annular locating ring which is provided with a frusto conical abutment.  
     
     
         13 . A turbine rotor as claimed in  claim 1  in which the at least one further abutment means of each radial body means is radially tapered.  
     
     
         14 . A turbine rotor as claimed in  claim 13  when dependent on  claim 12  in which the radially tapered abutment means is in the form of a flange extending in the axial direction, and, wherein on assembly, the flanges of all the radial body elements form an annular frusto conical tapered flange that is acted on by the frusto conical abutment of the annular locating ring.  
     
     
         15 . A turbine rotor as claimed in  claim 9  in which means is provided for directly securing together the two locating elements.  
     
     
         16 . A turbine rotor as claimed in  claim 15  in which the securing means comprises an axial clamping means.  
     
     
         17 . A turbine rotor as claimed in  claim 1  in which means is provided to secure the locating means individually to a separate connecting member.  
     
     
         18 . A turbine rotor as claimed in  claim 17  in which the separate connecting member comprises the axle element.  
     
     
         19 . A turbine rotor as claimed in  claim 17  in which said means comprises a tapered locking element.  
     
     
         20 . A turbine rotor as claimed in  claim 19  in which each locating ring is provided with its own tapered locking ring comprising two relatively moveable parts which engage between the connecting member and the locating ring and in which at least one locking ring acts to generate an axial movement of the locating ring relative to the connecting member and thereby cause the radial body members and hence the impeller elements to be drawn inwardly by virtue of the co-operating tapered abutment surfaces.  
     
     
         21 . A turbine rotor as claimed in  claim 17  when dependent on  claim 16  in which the respective means to locate each annular locating element are provided in addition to the aforesaid axial clamping means.  
     
     
         22 . A turbine rotor as claimed in  claim 1  in which the turbine rotor is a Pelton wheel runner and the impeller elements are buckets.