Abstract: A method for positioning a rotary part on a machining fixture adapted to hold the rotary part for a machining operation is described. The machining fixture has a center axis and a diaphragm with engaging segments affixed thereto and extending away therefrom. The method includes mounting the rotary part on the machining fixture concentrically about the center axis and adjacent to the engaging segments, and then applying an axial force in a direction substantially parallel to the center axis against the diaphragm. This elastically deforms the diaphragm and radially displaces the contact members of the engaging segments into frictional engagement with a circumferential surface of the rotary part.

Abstract: A grinding machine for finishing turned surfaces of a rotor disc for a gas turbine engine, including a retaining mechanism for retaining the rotor disc and rotatable about a rotational axis corresponding to a central axis of the rotor disc, a spindle engaged to a grinding wheel and rotatable about a rotational axis corresponding to a central axis of the grinding wheel, the grinding wheel having an outer super abrasive surface, a translating mechanism engaged to at least one of the retaining mechanism and the spindle and actuable to provide a relative translational motion between the retaining mechanism and the spindle along three perpendicular axes, and a pivoting mechanism engaged to one of the retaining mechanism and the spindle and actuable to provide a pivoting motion of the rotational axis of one of the retaining mechanism and the spindle around a pivot axis perpendicular thereto.

Abstract: A method for distributing a coolant to a grinding site of a grinding wheel, including rotating the grinding wheel, injecting the coolant in an inlet of the grinding wheel disposed proximate to an axis of rotation of the grinding wheel, moving the coolant fluid from the inlet along a plurality of internal grooves of the grinding wheel outwardly towards a plurality of outlets, and expelling the coolant outwardly from the plurality of outlets at an angle of at most 15 degrees with respect to a tangent to a circumference of the grinding wheel at the outlet.

Abstract: A method for positioning a rotary part on a machining fixture adapted to hold the rotary part for a machining operation is described. The machining fixture has a center axis and a diaphragm with engaging segments affixed thereto and extending away therefrom. The method includes mounting the rotary part on the machining fixture concentrically about the center axis and adjacent to the engaging segments, and then applying an axial force in a direction substantially parallel to the center axis against the diaphragm. This elastically deforms the diaphragm and radially displaces the contact members of the engaging segments into frictional engagement with a circumferential surface of the rotary part.

Abstract: A positioning assembly for positioning a rotary part to be machined includes a machining fixture and a positioning device having an elastically-deformable diaphragm concentrically mounted to the fixture and defining an annular loading zone which receives an axial force substantially parallel with a center axis of the fixture. The positioning device has circumferentially-spaced engaging segments, fixed to the diaphragm and extending away therefrom, which have contact members that are displaced radially to frictionally engage the rotary part when the axial force is applied to the loading zone of the diaphragm.

Abstract: A grinding machine for finishing turned surfaces of a rotor disc for a gas turbine engine, including a retaining mechanism for retaining the rotor disc and rotatable about a rotational axis corresponding to a central axis of the rotor disc, a spindle engaged to a grinding wheel and rotatable about a rotational axis corresponding to a central axis of the grinding wheel, the grinding wheel having an outer super abrasive surface, a translating mechanism engaged to at least one of the retaining mechanism and the spindle and actuable to provide a relative translational motion between the retaining mechanism and the spindle along three perpendicular axes, and a pivoting mechanism engaged to one of the retaining mechanism and the spindle and actuable to provide a pivoting motion of the rotational axis of one of the retaining mechanism and the spindle around a pivot axis perpendicular thereto.

Abstract: A method for providing a hole through a metal engine component having a base metal and thermal barrier coating layer forming a top surface of the component, the hole having a central axis extending at a hole angle of 20 degrees or less with respect to the top surface. The method includes laser trepanning through the thermal barrier coating layer without penetrating the base metal by moving a central axis of a pulse laser beam within a boundary of the hole, with the pulse laser beam having a first pulse energy level. The central axis of the pulse laser beam is then disposed within the boundary at the hole angle and shots of the pulse laser beam are applied to drill through the base metal and complete the hole, using a second pulse energy level different from the first pulse energy level.

Abstract: A method for drilling a shallow-angled hole through a thermal barrier coated component includes a step of applying a pulse laser beam to drill a section of the hole substantially within a thermal barrier coating of the component in a direction substantially perpendicular to a top surface of the component. A further step is conducted to apply the pulse laser beam to further drill through a base metal of the component to complete the formation of the hole extending through the component.

Abstract: A method of manufacturing turned surfaces of a rotor disc of a gas turbine engine, including rotating the rotor disc about its central axis, rotating an abrasive grinding wheel having an outer grinding surface with a hardness greater than that of a material of the rotor disc, contacting the rotating wheel with at least one annular surface of the rotating disc, and sliding the rotating wheel along a curved cross-sectional profile of the at least one annular surface of the rotating disc.

Abstract: A system and method for error compensation in positioning a complex-shaped gas turbine engine part during manufacturing thereof with a machine. Theoretical measurements for a plurality of control points on the part are first retrieved. Actual measurements for the control points are then acquired in a coordinate system of the machine. If an error between the actual and theoretical measurements is beyond a tolerance, a transformation matrix is computed. The transformation matrix represents a transformation to be applied to the coordinate system to adjust a pose thereof for compensating the error. The transformation matrix may be computed and applied to the coordinate system iteratively until the actual measurements are brought within tolerance. A machining program may then be generated for manufacturing the part accordingly.

Abstract: A method for distributing a coolant to a grinding site of a grinding wheel, including rotating the grinding wheel, injecting the coolant in an inlet of the grinding wheel disposed proximate to an axis of rotation of the grinding wheel, moving the coolant fluid from the inlet along a plurality of internal grooves of the grinding wheel outwardly towards a plurality of outlets, and expelling the coolant outwardly from the plurality of outlets at an angle of at most 15 degrees with respect to a tangent to a circumference of the grinding wheel at the outlet.

Abstract: Methods and systems for calculating a feedrate for programming a multi-axis machining tool. For at least one control block in a defined machining path: a displacement of a defined machine control point from a previous control block to a current control block is determined; a displacement of a defined feedrate control point from the previous control block to the current control block is determined; a compensation ratio is calculated as a ratio between the displacement of the defined machine control point and the displacement of the defined feedrate control point; and a feedrate for the machine control point is calculated by applying the compensation ratio to a desired feedrate. The calculated federate is used in a control block of a multi-axis machining tool.

Abstract: A grinding wheel including an impeller structure for circulating coolant within the wheel defining a plurality of grooves. An angle between a second wall of each groove and a tangent to the outer circumference adjacent the groove outlet is defined based on the desired coolant flow rate, the predetermined wheel rotational speed, the radius of the outer circumference of the impeller structure, the combined surface area of the groove outlets, and a desired angle of exit of the coolant being at most 15 degrees. Also, a wheel is disclosed where the angle of the second wall of each groove is defined based on the desired coolant flow rate, the combined surface area of the groove outlets, the tangential speed of the wheel, and a value of n being at least 0.9 and less than 1. A method for distributing a coolant to a grinding site is also discussed.

Abstract: An apparatus for forming a firtree slot in a disc of a bladed rotor assembly for a gas turbine engine may include a tip portion having the shape of the profile of one side of the firtree slot to be formed but smaller than the profile of the complete firtree slot so that the tool will only engage one side of the firtree slot.

Abstract: A positioning assembly for positioning a rotary part to be machined includes a machining fixture and a positioning device having an elastically-deformable diaphragm concentrically mounted to the fixture and defining an annular loading zone which receives an axial force substantially parallel with a center axis of the fixture. The positioning device has circumferentially-spaced engaging segments, fixed to the diaphragm and extending away therefrom, which have contact members that are displaced radially to frictionally engage the rotary part when the axial force is applied to the loading zone of the diaphragm.

Abstract: A grinding wheel including an impeller structure for circulating coolant within the wheel defining a plurality of grooves. An angle between a second wall of each groove and a tangent to the outer circumference adjacent the groove outlet is defined based on the desired coolant flow rate, the predetermined wheel rotational speed, the radius of the outer circumference of the impeller structure, the combined surface area of the groove outlets, and a desired angle of exit of the coolant being at most 15 degrees. Also, a wheel is disclosed where the angle of the second wall of each groove is defined based on the desired coolant flow rate, the combined surface area of the groove outlets, the tangential speed of the wheel, and a value of n being at least 0.9 and less than 1. A method for distributing a coolant to a grinding site is also discussed.

Abstract: A system and method for error compensation in positioning a complex-shaped gas turbine engine part during manufacturing thereof with a machine. Theoretical measurements for a plurality of control points on the part are first retrieved. Actual measurements for the control points are then acquired in a coordinate system of the machine. If an error between the actual and theoretical measurements is beyond a tolerance, a transformation matrix is computed. The transformation matrix represents a transformation to be applied to the coordinate system to adjust a pose thereof for compensating the error. The transformation matrix may be computed and applied to the coordinate system iteratively until the actual measurements are brought within tolerance. A machining program may then be generated for manufacturing the part accordingly.

Abstract: A method for operating a machining tool, comprising: setting a flow rate and a pressure of a flow of coolant to a target flow rate and a pressure target, respectively, the coolant flow being provided to the machining tool; machining a work-piece using the machining tool; measuring the flow rate and the pressure of the flow of coolant; and detecting an anomaly with respect to the coolant flow; and taking a corrective action depending on the type of the detected anomaly.

Abstract: Methods and systems for calculating a feedrate for programming a multi-axis machining tool. For at least one control block in a defined machining path: a displacement of a defined machine control point from a previous control block to a current control block is determined; a displacement of a defined feedrate control point from the previous control block to the current control block is determined; a compensation ratio is calculated as a ratio between the displacement of the defined machine control point and the displacement of the defined feedrate control point; and a feedrate for the machine control point is calculated by applying the compensation ratio to a desired feedrate. The calculated federate is used in a control block of a multi-axis machining tool.

Abstract: A method for operating a machining tool, comprising: setting a flow rate and a pressure of a flow of coolant to a target flow rate and a pressure target, respectively, the coolant flow being provided to the machining tool; machining a work-piece using the machining tool; measuring the flow rate and the pressure of the flow of coolant; and detecting an anomaly with respect to the coolant flow; and taking a corrective action depending on the type of the detected anomaly.