Shaft sealing apparatus

A shaft sealing apparatus, comprising:

• a vacuum casing formed with a vacuum chamber and having a base portion formed with an opening to have said vacuum chamber of said vacuum casing held in communication with the atmosphere through said opening of said vacuum casing;
• a shaft housing in the form of a cylindrical hollow shape and fixedly connected with said base portion of said vacuum casing, said shaft housing having an inner cylindrical surface;
• a driving shaft in the form of a cylindrical shape and received in said shaft housing to be movably supported by said shaft housing, said driving shaft held in coaxial alignment with said shaft housing and having a first axial end extending in said vacuum chamber of said vacuum casing, a second axial end extending in the atmosphere, and an outer cylindrical surface smaller in diameter than said inner cylindrical surface of said shaft housing;
• and
• a sealing unit received in said opening of said vacuum casing and fixedly supported by said base portion of said vacuum casing, said sealing unit including a retaining member in the form of an annular ring shape and fixedly connected with said base portion of said vacuum casing, and a sealing ring in the form of an annular ring shape and securely retained by said retaining member of said sealing unit, said sealing ring of said sealing unit intervening between said driving shaft and said retaining member of said sealing unit to hermetically seal the gap between said driving shaft and said retaining member of said sealing unit, said sealing ring of said sealing unit including an annular resilient member formed with an annular groove, and an annular spring member received in said annular groove of said annular resilient member and retained by said annular resilient member, said annular resilient member of said sealing ring having a peripheral portion securely retained by said retaining member, and a sealing lip integrally formed with said peripheral portion of said annular resilient member and radially inwardly extending from said peripheral portion of said annular resilient member to be held in contact with said outer cylindrical surface of said driving shaft, said annular spring member of said sealing ring operative to impart a force to said sealing lip of said annular resilient member to ensure that said sealing lip of said annular resilient member is held in tight contact with said outer cylindrical surface of said driving shaft.

A shaft sealing apparatus, comprising:

• a vacuum casing formed with a vacuum chamber and having a base portion formed with an opening to have said vacuum chamber of said vacuum casing held in communication with the atmosphere through said opening of said vacuum casing;
• a shaft housing in the form of a cylindrical hollow shape and fixedly connected with said base portion of said vacuum casing, said shaft housing having an inner cylindrical surface;
• a sleeve shaft in the form of a cylindrical hollow shape and received in said shaft housing to be movably supported by said shaft housing, said sleeve shaft held in coaxial alignment with said shaft housing and having a first axial end extending in said vacuum chamber of said vacuum casing, a second axial end extending in the atmosphere, an outer cylindrical surface smaller in diameter than said inner cylindrical surface of said shaft housing, and an inner cylindrical surface;
• a center shaft in the form of a cylindrical shape and received in said sleeve shaft to be movably supported by said sleeve shaft, said center shaft held in coaxial alignment with said sleeve shaft and having a first axial end extending in said vacuum chamber of said vacuum casing, a second axial end extending in the atmosphere, and an outer cylindrical surface smaller in diameter than said inner cylindrical surface of said sleeve shaft;
• a first sealing unit provided on said first axial end of said sleeve shaft and held in coaxial alignment with said sleeve shaft, said first sealing unit including a retaining member in the form of an annular ring shape and fixedly connected with said first axial end of said sleeve shaft, and a sealing ring in the form of an annular ring shape and securely retained by said retaining member of said first sealing unit, said sealing ring of said first sealing unit intervening between said center shaft and said retaining member of said first sealing unit to hermetically seal the gap between said center shaft and said retaining member of said first sealing unit, said sealing ring of said first sealing unit including an annular resilient member formed with an annular groove, and an annular spring member received in said annular groove of said annular resilient member and retained by said annular resilient member, said annular resilient member of said sealing ring having a peripheral portion securely retained by said retaining member, and a sealing lip integrally formed with said peripheral portion of said annular resilient member and radially inwardly extending from said peripheral portion of said annular resilient member to be held in contact with said outer cylindrical surface of said center shaft, said annular spring member of said sealing ring operative to impart a force to said sealing lip of said annular resilient member to ensure that said sealing lip of said annular resilient member is held in tight contact with said outer cylindrical surface of said center shaft;
• and
• a second sealing unit received in said opening of said vacuum casing and fixedly supported by said base portion of said vacuum casing, said second sealing unit including a retaining member in the form of an annular ring shape and fixedly connected with said base portion of said vacuum casing, and a sealing ring in the form of an annular ring shape and securely retained by said retaining member of said second sealing unit, said sealing ring of said second sealing unit intervening between said retaining member of said first sealing unit and said retaining member of said second sealing unit to hermetically seal the gap between said retaining member of said first sealing unit and said retaining member of said second sealing unit, said sealing ring of said second sealing unit including an annular resilient member formed with an annular groove, and an annular spring member received in said annular groove of said annular resilient member and retained by said annular resilient member, said annular resilient member of said sealing ring having a peripheral portion securely retained by said retaining member, and a sealing lip integrally formed with said peripheral portion of said annular resilient member and radially inwardly extending from said peripheral portion of said annular resilient member to be held in contact with said outer cylindrical surface of said first sealing unit, said annular spring member of said sealing ring operative to impart a force to said sealing lip of said annular resilient member to ensure that said sealing lip of said annular resilient member is held in tight contact with said outer cylindrical surface of said first sealing unit.

A shaft sealing apparatus, comprising:

• a vacuum casing formed with a vacuum chamber and having a base portion formed with an opening to have said vacuum chamber of said vacuum casing held in communication with the atmosphere through said opening of said vacuum casing;
• a shaft housing in the form of a cylindrical hollow shape and fixedly connected with said base portion of said vacuum casing, said shaft housing having an inner cylindrical surface;
• a sleeve shaft in the form of a cylindrical hollow shape and received in said shaft housing to be movably supported by said shaft housing, said sleeve shaft held in coaxial alignment with said shaft housing and having a first axial end extending in said vacuum chamber of said vacuum casing, a second axial end extending in the atmosphere, an outer cylindrical surface smaller in diameter than said inner cylindrical surface of said shaft housing, and an inner cylindrical surface;
• a center shaft in the form of a cylindrical shape and received in said sleeve shaft to be movably supported by said sleeve shaft, said center shaft held in coaxial alignment with said sleeve shaft and having a first axial end extending in said vacuum chamber of said vacuum casing, a second axial end extending in the atmosphere, and an outer cylindrical surface smaller in diameter than said inner cylindrical surface of said sleeve shaft;
• a first sealing unit fixedly supported by said sleeve shaft, said first sealing unit including a retaining member in the form of an annular ring shape and fixedly supported by said sleeve shaft, and a sealing ring in the form of an annular ring shape and securely retained by said retaining member of said first sealing unit, said sealing ring of said first sealing unit intervening between said center shaft and said retaining member of said first sealing unit to hermetically seal the gap between said center shaft and said retaining member of said first sealing unit, said sealing ring of said first sealing unit including an annular resilient member formed with an annular groove, and an annular spring member received in said annular groove of said annular resilient member and retained by said annular resilient member, said annular resilient member of said sealing ring having a peripheral portion securely retained by said retaining member, and a sealing lip integrally formed with said peripheral portion of said annular resilient member and radially inwardly extending from said peripheral portion of said annular resilient member to be held in contact with said outer cylindrical surface of said center shaft, said annular spring member of said sealing ring operative to impart a force to said sealing lip of said annular resilient member to ensure that said sealing lip of said annular resilient member is held in tight contact with said outer cylindrical surface of said center shaft;
• and
• a second sealing unit fixedly supported by said base portion of said vacuum casing, said second sealing unit including a retaining member in the form of an annular ring shape and fixedly supported by said base portion of said vacuum casing, and a sealing ring in the form of an annular ring shape and securely retained by said retaining member of said second sealing unit, said sealing ring of said second sealing unit intervening between said sleeve shaft and said retaining member of said second sealing unit to hermetically seal the gap between said sleeve shaft and said retaining member of said second sealing unit, said sealing ring of said second sealing unit including an annular resilient member formed with an annular groove, and an annular spring member received in said annular groove of said annular resilient member and retained by said annular resilient member, said annular resilient member of said sealing ring having a peripheral portion securely retained by said retaining member, and a sealing lip integrally formed with said peripheral portion of said annular resilient member and radially inwardly extending from said peripheral portion of said annular resilient member to be held in contact with said outer cylindrical surface of said sleeve shaft, said annular spring member of said sealing ring operative to impart a force to said sealing lip of said annular resilient member to ensure that said sealing lip of said annular resilient member is held in tight contact with said outer cylindrical surface of said sleeve shaft.