Thermal expansion joint connection for sheet metal assembly

A method for connecting concentric first and second annular components of a gas turbine engine, wherein the first and second components are subject to different temperatures creating relative radial movement therebetween, at least one of the first and second components being a sheet metal component;

• the method comprising:
• (i) forming radially disposed slot apertures in a radially extending circumferential edge portion of an annular flange of said first component at predetermined locations thereabout, each of said radially disposed slot apertures defining opposed elongated spaced-apart parallel edges;
• (ii) forming hole apertures in a connecting radially extending circumferential edge portion of an annular flange of said second component at locations for confronting alignment with said slot apertures;
• (iii) overlapping in facial contact said circumferential edge portions of said first and second components with said slot apertures and hole apertures aligned;
• (iv) positioning a connecting sleeve, having an abutment flange projecting outwardly about an end thereof, in close fit into each of said hole apertures with said abutment flange contacting a peripheral surface region about said hole apertures on a first side of said second component opposite said first component and with said connecting sleeve projecting through said hole and slot apertures, each of the connecting sleeves having a slot engaging portion provided with opposed flat parallel walls spaced-apart for close sliding fit between the opposed elongated spaced apart parallel edges of the slot apertures;
• (v) positioning a retention washer having a receiving hole centrally disposed therethrough about a projecting end portion of each of the connecting sleeves on an outer side of the first component for abutment against an outer surface of the first component, each retention washer comprising an outer wall formation for abutting the head of a fastener extending therethrough;
• and
• (vi) positioning fasteners through said receiving holes in said retention washers and respective holes extending longitudinally through said connecting sleeves and securing said fasteners to clampingly interconnect said circumferential edge portions of said first component to said second component while permitting relative radial movement between the first and second components by displacement of the connecting sleeves with the fasteners in associated ones of the radially disposed slot apertures.

A sheet metal assembly for a gas turbine engine, the sheet metal assembly comprising:

• concentric first and second annular sheet metal components, and
• at least one thermal expansion joint between the first and second sheet metal components;
• said at least one thermal expansion joint comprising:
• a slot aperture formed in a radially extending edge portion of an annular flange of the first sheet metal component, the slot aperture having opposed parallel radially extending straight edges;
• a corresponding hole aperture formed in a radially extending edge portion of an annular flange of the second sheet metal component and disposed for confronting alignment with the slot aperture;
• a connecting sleeve mounted on a first side of the second sheet metal component opposite to said first sheet metal component, the connecting sleeve projecting through both the hole aperture and slot aperture, the connecting sleeve having a slot engaging portion provided with opposed flat parallel walls spaced-apart for closed sliding fit between the opposed radially extending straight edges of the slot aperture;
• a retention washer having a hole centrally disposed therethrough engaged over an end portion of the connecting sleeve on a side of the first sheet metal component opposite to the second sheet metal component, the retention washer comprising an outer wall formation for abutting the head of a fastener extending therethrough;
• and
• a fastener extending through both the retention washer and the connecting sleeve to clampingly interconnect the overlapped edge portions of the first and second sheet metal components while permitting relative radial movement of the first and second sheet metal components by displacement of the connecting sleeve with the fastener in the slot aperture.