Double wall bearing cone

Details Double wall bearing cone Double wall bearing cone

1999-12-15

2001-07-31

Freay, Charles G. (Department: 3746)

Power plants

Combustion products used as motive fluid

Combustion products generator

C060S039300, C060S039300, C060S039130, C060S260000

Reexamination Certificate

active

06266954

ABSTRACT:

BACKGROUND OF THE INVENTION
The invention relates to cooling in a gas turbine and, more particularly, to a double wall bearing cone that closes the opening between the bearing housing and the exhaust frame structure in a gas turbine.
A bearing cone is a barrier wall in a gas turbine that closes the opening between the bearing housing and the exhaust frame structure of the gas turbine. As shown in
FIG. 1
, this barrier wall
100
creates a cavity
102
around the rotor aft shaft
104
and the turbine third stage wheel
106
that is supplied with purge air to prevent leakage of hot turbine exhaust gas into the cavity
102
. Normally, air discharging from the exhaust frame cooling circuit is used to pressurize and purge the rotor aft shaft cavity
102
.
Problems resulting from wear have been noted in the turbine third stage wheel and rotor aft shaft rabbet joint due to adverse thermal gradients in the rotor created by the purge air conditions in the aft shaft cavity. Impingement of exhaust frame cooling air on the aft face of the third stage wheel and leakage of cold bearing tunnel air across the bearing cone into the rotor aft shaft cavity (see arrows in
FIG. 1
) are major contributors to the adverse thermal gradients.
BRIEF SUMMARY OF THE INVENTION
A cooling circuit modification is thus helpful to improve the thermal boundary conditions on the rotor aft shaft. In an exemplary embodiment of the invention, a bearing cone that closes an opening between a bearing housing and an exhaust frame in a gas turbine includes a conical forward plate having an inner diameter and an outer diameter. A conical aft plate is nested with and spaced from the conical forward plate and also includes an inner diameter and an outer diameter. A hub connects the inner diameters of the forward plate and the aft plate. The hub is preferably provided with holes therein that serve to meter air flow between the forward plate and the aft plate. The forward and aft plates are connected to forward and aft supporting plates at the respective outer diameters. Gusset plates may also be provided, connecting the forward and aft supporting plates.
In another exemplary embodiment of the invention, an exhaust frame cooling circuit in a bearing housing of a gas turbine is defined by cooling air flow through the bearing cone of the invention. The cooling circuit includes an air flow path between the forward plate and the aft plate of the bearing cone.
In still another exemplary embodiment of the invention, a gas turbine includes a bearing housing supporting a turbine wheel, and an exhaust frame receiving hot combustion gas and including a cooling circuit. The bearing cone of the invention is disposed in an opening between the bearing housing and the exhaust frame. The exhaust frame may include a slot receiving the bearing cone aft supporting plate, wherein a rope packing seal is disposed between the bearing cone aft supporting plate and the slot. The hub is preferably engaged with the bearing housing via a wave seal. The conical forward plate of the bearing cone is engaged with an inner barrel ID of the exhaust frame via a floating split ring seal.


REFERENCES:
patent: 5307622 (1994-05-01), Ciokajlo et al.
patent: 6067792 (2000-05-01), Tubbs
patent: 1103638 (1961-03-01), None

Affiliated with

Also associated with

Rating

Double wall bearing cone does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Double wall bearing cone, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Double wall bearing cone will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2513609