Pratt-whitney Canada Corp

Amr Elfizy

Ghislain Hardy

Yuwen Li

Sylvain Cournoyer

Lafleche Gagnon

James Leishman

Sylvain Jette

Yannick Dupont

François Perron

Sylvian Jette

Sylvain Jetté

Vincent Thomasset-Laperriere

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.

Positioning assembly and method

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.

Method of machining surfaces of rotor disc and grinding machine therefor

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.

Grinding wheel and method

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.

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.

Laser drilling methods of shallow-angled holes

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.

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.

System and method for positioning error compensation during manufacturing of complex-shaped gas turbine engine parts

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.

Methods and systems for calculation of feedrate

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.

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.

Apparatus for providing firtree slots

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.

Active coolant flow control for machining processes

A method for providing a shallow-angled hole through a thermal barrier coated component in accordance with one aspect thereof, includes a step of applying a pulse laser beam to pre-drill the hole through a base metal of the component. A thermal barrier coating is then applied to the base metal, covering the pre-drilled hole in the base metal. A further step is conducted to apply the pulse laser beam through the thermal barrier coating a location to coincide with pre-drilled hole in the base metal in order to complete the formation of the hole extending through the component.

A method for drilling a shallow-angled hole through a thermal barrier coated component, in accordance with one aspect thereof, includes a step of applying a pulse laser beam with a first setting to drill a section of the hole substantially within a thermal barrier coating of the component. A further step is conducted to apply the pulse laser beam with a second setting through the initiated hole to further drill through a remainder of the component to complete the formation of the hole extending through the component.

A system for machining a work-piece is described which includes a machine tool and coolant delivery unit, pressure and flow rate sensors, and a control unit. The control unit controls coolant delivery and is adapted to detect a first anomaly when either a measured flow rate or pressure deviates from target flow rates and pressures by a first predetermined amount, and to detect a second anomaly when the measured flow rate or pressure deviates from the target flow rates and pressures by a second predetermined amount greater than the first. An alarm signal is outputted when the first anomaly is detected, and the machine tool is stopped when the second anomaly is detected.

A process for forming a firtree slot in a disc of a bladed rotor assembly for a gas turbine engine may include making a first pass with a machining quill to form a rough profile of the firtree slot, making a second pass with an inclined machining quill having the shape of one of the finished side wall profile of the firtree slot and avoiding engagement with the other side, and making a third pass with an inclined second quill having the shape of the other of the finished side wall profile of the firtree slot and avoiding engagement with the other side, in order to provide a firtree slot for receiving and fixing the root of a blade.

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Longueuil, Canada

Amr Elfizy