Multi-part dovetail repair broach assembly and methods of use
First Claim
1. A broach assembly for establishing contact surfaces in a dovetail slot of a turbine wheel with surfaces of a bucket dovetail receivable in the slot, comprising:
- a sub-assembly including a plurality of cutters having cutting surfaces about margins of the cutters and a plurality of spacers interposed between said cutters;
a lead and a lag carried by said sub-assembly adjacent opposite ends thereof for respectively leading the sub-assembly into the slot and facilitating withdrawal of the sub-assembly from the slot;
each of said lead, lag, cutters and spacers having a dovetail shape generally corresponding to the shape of the dovetail slot, said spacers having an apex;
said spacers having progressively tapered surfaces along said apices thereof and in a direction from said lead toward said lag for engaging a surface in the slot enabling generally oppositely facing cutting surfaces of said cutters to progressively cut the contact surfaces of the slot as the assembly passes through the slot lead end first.
1 Assignment
0 Petitions
Accused Products
Abstract
The broach assembly includes alternate spacers and cutters arranged in a sub-assembly having a lead at a leading end and a lag at a trailing end. The cutters have side margins in excess of the margins of the spacers for cutting material from the dovetail slots of the turbine wheel as the broach assembly passes through the slots. The bottom or apices of each spacer is tapered and extends beyond the corresponding surface of the cutter to progressively displace the assembly in a radial outward direction to progressively cut the active dovetail slot surfaces. Shims may be disposed in the bottom of the slot to further displace the broach assembly radially outwardly in multiple passes.
38 Citations
31 Claims
-
1. A broach assembly for establishing contact surfaces in a dovetail slot of a turbine wheel with surfaces of a bucket dovetail receivable in the slot, comprising:
-
a sub-assembly including a plurality of cutters having cutting surfaces about margins of the cutters and a plurality of spacers interposed between said cutters;
a lead and a lag carried by said sub-assembly adjacent opposite ends thereof for respectively leading the sub-assembly into the slot and facilitating withdrawal of the sub-assembly from the slot;
each of said lead, lag, cutters and spacers having a dovetail shape generally corresponding to the shape of the dovetail slot, said spacers having an apex;
said spacers having progressively tapered surfaces along said apices thereof and in a direction from said lead toward said lag for engaging a surface in the slot enabling generally oppositely facing cutting surfaces of said cutters to progressively cut the contact surfaces of the slot as the assembly passes through the slot lead end first. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
-
10. A broach assembly for establishing contact surfaces in a slot of a first part with surfaces of a second part receivable in the slot, comprising:
-
a plurality of cutters each having an opening therethrough and cutting surfaces about margins of the cutters;
a plurality of spacers each having an opening therethrough and interposed between said cutters;
an element passing through said openings and cooperable with the cutters and spacers to form a sub-assembly of cutters and spacers;
a lead and a lag carried by said sub-assembly adjacent opposite ends thereof for respectively leading the sub-assembly into the slot and facilitating withdrawal of the sub-assembly from the slot;
said spacers having progressively tapered surfaces along a side of said sub-assembly and in a direction from said lead toward said lag for engaging a surface in said slot enabling generally oppositely facing cutting surfaces of said cutters to progressively cut the contact surfaces of the slot as the assembly passes through the slot lead end first. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
-
-
23. A method of progressively cutting surfaces in a slot of a first part to establish contact with mating surfaces of a second part receivable in the cut slot comprising the steps of:
-
providing a broach assembly including a sub-assembly of alternating cutters and spacers each having a marginal configuration generally conforming to the configuration of the slot with said spacer margins being inset from the cutter margins;
forming tapers along surfaces of the spacers on a side of the sub-assembly facing generally opposite to cutting surfaces formed on the cutters; and
passing the sub-assembly through the slot with the tapered spacer surfaces engaging a surface in the slot and in a direction enabling the cutting surfaces of the cutters to progressively cut the surfaces of the slot to form contact surfaces for engaging the mating surfaces of the second part upon reception of the second part in the cut slot of the first part. - View Dependent Claims (24, 25, 26, 27, 28, 29, 30, 31)
-
Specification