Sealing apparatus and method and machinery utilizing same

A turbo machine comprising:

• a housing defining a bore;
• a rotatable shaft means received in said bore;
• a compressor wheel mounted on said shaft means for rotation therewith, said compressor wheel discharging pressurized air to a discharge area;
• a sealing structure circumscribing said shaft means and cooperating with said shaft means and said housing to resist leakage therepast of a liquid in response to a flow of pressurized air into a chamber of said sealing structure;
• flow path means within said shaft means communicating said compressor discharge area with said chamber of said sealing structure for supplying said flow of pressurized air to the latter;
• and
• centrifugally responsive valve means carried by said shaft means for controlling said flow of pressurized air as a function of shaft means rotational speed.

A turbo machine comprising:

• a housing defining a bore;
• a rotatable shaft means received in said bore;
• a compressor wheel mounted on said shaft means for rotation therewith, said compressor wheel discharging pressurized air to a discharge area;
• a sealing structure circumscribing said shaft means and cooperating with said shaft means and said housing to resist leakage therepast of a liquid in response to a flow of pressurized air into a chamber of said sealing structure;
• flow path means within said shaft means communicating said compressor discharge area with said chamber of said sealing structure for supplying said flow of pressurized air to the latter;
• and
• centrifugally responsive valve means carried by said shaft means for controlling said flow of pressurized air as a function of shaft means rotational speed;
• wherein said compressor wheel defines a back face communicating with said discharge area, said turbo machine further including a turbine wheel mounted on said shaft means for rotation therewith, said compressor wheel and said turbine wheel being axially spaced apart in back-to-back relation to define a radially extending axial space therebetween, said housing including a partition member extending radially inwardly toward said shaft means within said space, said partition member defining an opening circumscribing said shaft means and cooperating with said back face to define a clearance space, a seal apparatus cooperating with said partition member and with said shaft means to substantially prevent fluid flow therebetween, said flow path means including a fluid flow passage opening to said clearance space and communicating said discharge area with said chamber of said sealing structure.

The method of controlling a flow of pressurized sealing fluid from a source thereof whose pressure level is a function of the rotational speed of a shaft means to a sealing apparatus cooperating with said shaft means and a housing to prevent leakage of another fluid therebetween, said method comprising the steps of:

• forming flow path means within said shaft means for communicating said flow of sealing fluid from said source thereof to said seal apparatus;
• disposing a centrifugally responsive valve element within said flow path means for rotation with said shaft means to control said flow of sealing fluid as a function of rotational speed of said shaft means;
• and
• utilizing said flow of sealing fluid to said sealing apparatus to prevent leakage of said another fluid between said shaft means and said housing.

In a turbo machine having a housing journaling a shaft means, said shaft means carrying a compressor wheel discharging pressurized air to a discharge area;

• the method of forming a seal between said housing and said shaft means which is resistant to the leakage of a liquid therepast, said method comprising the steps of:
• forming a sealing structure between said housing and said shaft means, said sealing structure resisting the leakage of said liquid therepast in response to a flow of pressurized air into a chamber of said sealing structure;
• forming flow path means within said shaft means leading from said discharge area to said chamber of said sealing structure for communicating a flow of said pressurized air to the latter;
• disposing a centrifugally responsive valve means in said flow path means for controlling said flow of pressurized air as a function of shaft means rotational speed;
• and
• utilizing said flow of pressurized air to resist leakage of a liquid between said housing and shaft means at said seal structure.

The method of matching a flow of pressurized air from an air pressure generator whose pressure level is a function of a shaft means rotational speed to the air flow requirement of a shaft means sealing apparatus cooperating with said shaft means to block the leakage of a liquid therealong, said method comprising the steps of:

• forming a flow path communicating said flow of pressurized air within said shaft means to said sealing apparatus;
• disposing centrifugally responsive valve means in said shaft means for controlling said flow of pressurized air through said flow path as a function of rotational speed;
• and
• utilizing said flow of pressurized air to block leakage of said liquid along said shaft means at said sealing apparatus.