Patent Application
20120051917
1. Field of the Invention
This invention relates to connecting aircraft gas turbine engine rotor components.
2. Discussion of the Background Art
Gas turbine engines frequently have multi-stage turbine rotors having adjacent co-rotating components such as interstage seals located between adjacent first and second stage turbine disks. The interstage seal may be connected to the first stage disk and the second stage disk by boltless connections, thereby, eliminating the time-consuming task of properly torquing the bolts and eliminating the stress concentration problems associated with bolted connections. An example of such a connection is disclosed in U.S. Pat. No. 5,320,488, titled “Turbine Disk Interstage Seal Anti-rotation System”, by Meade et al., and issued Jun. 14, 1994.
Aircraft engine rotors carry large torque loads and separate torque loads applied to separate components must be carried though the interfaces or connections connecting the components to avoid component slipping. If components slip at the connecting or mating interfaces hardware may be damage and is subject to fretting.
Anti rotation or torque and slip countering features such as keys, tabs, or splines to carry toque are well known in art. Boltless connections also incorporate rabbets and their interface load with friction to avoid slipping. These features are costly three dimensional features and splines and tabs are also highly stressed.
Accordingly, there is a need for a turbine engine rotor boltless connection between rotor components that provides improved anti rotation or torque and slip effectiveness and more robust in countering rotation and associated rotational slippage than rabbets. There is also a need for boltless connections that are less expensive and less complicated than three dimensional features such as splines and tabs.
A gas turbine engine rotor assembly includes a first rotor component connected to a second rotor component by a connection. The connection includes an annular sleeve on the first rotor component, an annular tapered conical slot extending axially inwardly into the sleeve from an annular opening of the slot, the tapered conical slot tapering axially into the sleeve from the opening, and a sleeve inner conical surface in part bounding the conical slot. The second rotor component includes an annular rim received within the conical slot the annular rim and a rim inner conical surface mating with and pressing against the sleeve inner conical surface.
The assembly may further includes a sleeve cylindrical outer surface in part bounding the conical slot in the sleeve and a rim outer cylindrical surface on the annular rim. The annular rim outer cylindrical surface mates with and contacts the sleeve cylindrical outer surface.
An annular lip extending radially inwardly from the sleeve and sleeve inner conical surface at the annular opening to the conical slot may be incorporated.
The connection may be used in a gas turbine engine rotor assembly including an interstage seal axially disposed between and connected to first and second stage disks circumscribed about a centerline axis. The annular sleeve may be on the first stage disk and the interstage seal and the annular rim on the interstage seal.
The annular rim may be on a forward arm extending axially from an annular outer shell of the interstage seal towards the first stage disk. The sleeve may be on an aft boltless blade retainer mounted on the first stage disk.
The novel features believed characteristic of the present invention are set forth and differentiated in the claims. The invention, together with further objects and advantages thereof, is more particularly described in conjunction with the accompanying drawings in which:
Illustrated in
Referring to
Referring to
The shell 38 is generally cylindrical in shape, and the forward and aft arms 49, 50 each have an inwardly convex shape. More specifically, the forward and aft arms 49, 50 each have a catenary curve 51 which extends from the shell 38 to the respective first and second stage disks 14, 16.
Referring to
The collet boltless connection 8 further includes an annular rim 64 on a forward end 66 of the forward arm 49. The rim 64 is received within the conical slot 53 in the sleeve 52. The rim 64 includes a rim inner conical surface 70 and a rim outer cylindrical surface 72. The rim inner conical surface 70 mates with, contacts, and presses against the sleeve inner conical surface 56.
The rim inner conical surface 70 and the sleeve inner conical surface 56 have substantially the same conical angle AC with respect to the centerline axis 11. There may be a small difference between the conical angles of the rim inner conical surface 70 and the sleeve inner conical surface 56 to accommodate radial deflection. The rim outer cylindrical surface 72 mates with and contacts the sleeve cylindrical outer surface 60. The connection 8 locks or secures the annular rim 64 on the forward arm 49 of the interstage seal 12 within the conical slot 53 in the sleeve 52 of the first stage disk assembly 41 thus preventing or resisting circumferential slipping between and related fretting of the mating surfaces.
An annular lip 80 extends radially inwardly from the sleeve 52 and sleeve inner conical surface 56 at the annular opening 54 to the conical slot 53. The annular lip 80 is provided to allow a tool to be used to disassemble and separate the first and second rotor components 40, 42 and more particularly the rim 64 from the sleeve 52.
While there have been described herein, what are considered to be preferred and exemplary embodiments of the present invention, other modifications of the invention shall be apparent to those skilled in the art from the teachings herein and, it is, therefore, desired to be secured in the appended claims all such modifications as fall within the true spirit and scope of the invention.
Accordingly, what is desired to be secured by Letters Patent of the United States is the invention as defined and differentiated in the following claims:
