Sealing mechanism for a vacuum heat treating furnace

摘要

An apparatus for sealing a fan drive shaft in a vacuum heat treating furnace is disclosed. The sealing apparatus includes a housing having an annular body and a central opening. An inflatable first seal surrounds the central opening of the annular body. A second seal surrounds the central opening and is adjacent to the inflatable first seal. The sealing apparatus also includes a channel formed in the annular body adjacent to the second seal for conducting a purging fluid into the central opening. A means for injecting the purging fluid into the central opening is operably connected to the channel. A vacuum heat treating furnace and a fan drive system incorporating the sealing apparatus are also described.

主权项

1. An apparatus configured as a cartridge for sealing a fan drive shaft in a heat treating furnace, comprising:
(a) an annular housing having the following features: an inside circumference that defines a central opening along the length of said annular housing, a first circumferential channel that extends around said inside circumference, a first radially directed channel extending from the first circumferential channel to an outer circumference of the annular housing, a second circumferential channel that extends around said inside circumference, a second radially directed channel extending from the second circumferential channel to the outer circumference of the annular housing, and a third circumferential channel that extends around said inside circumference and is axially spaced from the second circumferential channel on one side thereof, (b) an inflatable first seal positioned in the first circumferential channel and the first radially directed channel and surrounding the central opening of said annular housing; (c) a sleeve positioned in the central opening concentrically with said annular housing; (d) a first ring positioned inside the third circumferential channel and surrounding said sleeve; said sleeve having: an inside diameter dimensioned to fit around a fan drive shaft, and an outside diameter dimensioned to provide a space between said sleeve and the inside circumference of said annular housing such that said sleeve can rotate freely; wherein said first ring has an inside diameter dimensioned to provide a gap between the ring and the sleeve and wherein the gap is dimensioned to permit gas to flow therethrough.