TECHNICAL FIELD

The present disclosure relates generally to sealing arrangements in high temperature environments. More specifically, the present disclosure relates to welded bellows and systems for sealing about a rotating component such as a shaft.

BACKGROUND

Mechanical face seals are widely used to provide sealing between a stationary housing, often containing a fluid such as oil, and a rotating shaft that passes through the housing. Typically, dynamic sealing (e.g., primary sealing) is provided by a sealing ring that does not rotate relative to the housing, and a mating ring that rotates with the rotating shaft. A welded bellows is used to provide axial loading of the dynamic sealing between the sealing ring and the mating ring. The welded bellows also provides static sealing (e.g., secondary sealing) that can accommodate axial movement between the shaft and the housing (e.g., caused by thermal expansion/contraction). Example face seals with welded bellows are disclosed by US 2014/0265146 and U.S. Pat. No. 8,714,558.

While welded bellows seals are effective, improvements in this area are still needed.

SUMMARY

One aspect of the present disclosure relates to a sealing arrangement. The sealing arrangement can include a composite seal ring with a seal ring shell that has a first end and an opposite second end. The composite seal ring can also include a seal insert that is adapted to be mounted at the first end of the seal ring shell. The sealing arrangement can include an outer housing positioned at the second end of the seal ring shell. The seal ring shell and the outer housing can be telescopically movable with respect to each other along a central axis such that relative axial sliding movement is permitted between the seal ring shell and the outer housing. The sealing arrangement can include at least one spring axially compressed between the seal ring shell and the outer housing for biasing the seal ring shell and the outer housing axially away from one another. The sealing arrangement can further include a welded bellows axially compressed between the seal ring shell and the outer housing. The welded bellows can have a fixed end and an opposite free end. The fixed end can be welded to the seal ring shell or the outer housing, and the opposite free end can make a non-welded contact seal with the other one of the seal ring shell or the outer housing.

Another aspect of the present disclosure relates to a sealing arrangement for sealing between a rotatable shaft and a casing through which the rotatable shaft extends. In one example, the rotatable shaft is an engine shaft and the casing defines a bearing compartment. In one example, the engine shaft is a drive shaft for a turbine engine applicable for aircraft. The sealing arrangement can include a composite seal ring that includes a seal ring shell and a seal insert. The seal ring shell surrounds a central axis and may extend along the central axis from a first end to an opposite second end. The seal insert can be mounted at the first end of the seal ring shell. The seal insert can have a sealing face that faces axially outwardly from the seal ring shell. The sealing face can be adapted to form a dynamic seal with respect to a mating ring that rotates with the rotatable shaft. The seal ring shell can include an outer radial flange located at an intermediate position between the first and second ends of the seal ring shell. The seal ring shell can include a piston portion that extends axially between the flange and the second end of the seal ring shell. The sealing arrangement can include an outer housing that telescopically receives the piston portion of the seal ring shell such that relative axial sliding movement along the central axis is permitted between the outer housing and the sealing ring shell. The outer housing can include an outer form factor adapted to be received within the casing of the bearing compartment. The sealing arrangement can include at least one spring axially compressed between the outer radial flange of the seal ring shell and the outer housing. The at least one spring can be utilized for generating a spring force that biases the seal ring shell and the outer housing axially away from each other. The sealing arrangement can further include a welded bellows that surrounds the central axis. The welded bellows can be positioned within the outer housing. The welded bellows can be axially compressed between an end wall defined by the piston portion of the sealing ring shell at the second end of the sealing ring shell and an end wall defined by the outer housing. The welded bellows have a fixed end and an opposite free end. The fixed end can be welded to one of the end walls, and the free end can make a non-welded static contact seal with the other one of the end walls.

A variety of additional aspects will be set forth in the description that follows. These aspects can relate to individual features and to combinations of features. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the broad concepts upon which the embodiments disclosed herein are based.

