Patent ID: 8601690
Filing Date: 2013-12-10
Classification: F01D,F02B,F05D,Y10T

Abstract:
1. A manufacturing method for manufacturing a variable capacity exhaust gas turbine, the gas turbine comprising: a turbine shaft supported by a bearing housing; a turbine rotor that is fixed to an end of the turbine shaft and rotationally driven by exhaust gas; an exhaust gas inlet through which the exhaust gas is supplied; an exhaust gas outlet through which the exhaust gas is discharged; and a turbine housing comprising: a scroll passage between said exhaust gas inlet and said turbine rotor, the cross-section area of the scroll passage gradually reduces along the direction of the exhaust gas stream, the scroll passage is provided with an inner scroll passage and an outer scroll passage into which the scroll passage is divided along a hoop direction around the turbine rotor, a plurality of insert vanes being provided in a row along the boundary between the inner scroll passage and the outer scroll passage, the row of insert vanes being configured so that the exhaust gas flow directly into the inner scroll passage and the exhaust gas flow into the inner scroll passage via the outer scroll passage are controlled, and a control valve that is arranged at an exhaust gas inlet side as to the outer scroll passage so as to control the exhaust gas flow rate into the inner scroll passage as well as into the outer scroll passage, and an opening end face that faces the bearing housing; the gas turbine further comprising: a cover that is arranged at the opening end face of the turbine housing so as to demarcate the inner scroll passage and the outer scroll passage, the insert vanes being provide so as to protrude from the body of the cover toward the side of the exhaust gas passage; wherein, a radius-reducing plate part is extended so as to form an integrated part together with the cover, the cover and the radius-reducing plate part being arranged in a gap between the bearing housing and the turbine rotor, along a plane vertical to the rotation axis of the turbine rotor; the cover and the radius-reducing plate part are formed as an integrated member by means of any one of casting, injection molding, or cold forging; a raw work-piece surface of the cover is provided with a protrusion part in a raw work-piece manufacturing stage so that the protrusion part protrudes from the raw work-piece surface of the cover to a direction near a tongue that is formed in the exhaust gas inlet of the inner scroll passage in the turbine housing as a part thereof, the protrusion part arranged to face the tongue; the integrated member as to the cover and the radius-reducing plate part is assembled into the gas turbine after the protrusion part is machined so that an allowable clearance is formed between the tongue and the protrusion part.