Rotary shaft fluid seal for high pressure

Claim 2

Seal means for effecting a fluid seal between a shaft and wall means defining a space extending outwardly of said shaft and disposed to receive said seal means, said wall means including bottom wall means having first and second bottom wall portion means, said first bottom wall portion means defining with said shaft a first perpendicular depth, said second bottom wall portion means defining with said shaft a second perpendicular depth, said first perpendicular depth being less than said second perpendicular depth, said seal means comprising an O-ring of rubberlike material defining first and second end sections with each end section having a pair of crown corners, said pair of crown corners on said first end section constituting a sealing section, said pair of crown corners on said second end section constituting a nonsealing section, one of said crown corners on said first end section confronting and sealingly engaging said shaft and constituting a shaft sealing crown corner, one of said crown corners on said second end section confronting said shaft and constituting a nonsealing crown corner therewith, said nonsealing crown corner being exposed to fluid pressure whereby said fluid pressure may act outwardly on said second end section and thereby tend to urge said shaft sealing crown corner in a direction outwardly of said shaft.

Claim 3

The structure of claim 1, wherein said O-ring has substantially a quadrilateral cross section.

Claim 4

Seal means for effecting a fluid seal between a shaft and wall means defining a space extending outwardly of said shaft and disposed to receive said seal means, said wall means including bottom wall means having first and second bottom wall portion means, said first bottom wall portion means defining with said shaft a first perpendicular depth, said second bottom wall portion means defining with said shaft a second perpendicular depth, said first perpendicular depth being less than said second perpendicular depth, said seal means comprising an O-ring of rubberlike material having an internal annular surface confronting said shaft and provided with first and second raised crown portions spaced apart from each other and including an internal valley portion therebetween and having an external annular surface confronting said bottom wall means and provided with third and fourth raised crown portions spaced apart from each other and including an external valley portion therebetween, said O-ring defining a first end section between said first and third crown portions and a second end section between said second and fourth crown portions, said first end section constituting a sealing section and having a free-state cross-sectional dimension between said first and third crown portions greater than said first perpendicular depth whereby said first end section is under a state of cross-sectional compression, said first crown portion directLy confronting and engaging said shaft and defining therewith a fluid seal, said second end section constituting a nonsealing section and having a free-state cross-sectional dimension between said second and fourth crown portions less than said second perpendicular depth, said second crown portion directly confronting said shaft and providing a nonsealing clearance therearound, said wall means also including downstream and upstream sidewall means, said first end section of said O-ring having end wall means facing said downstream sidewall means, said second end section of said O-ring having end wall means facing said upstream sidewall means, said second crown portion and said internal valley portion being exposed to fluid pressure whereby said fluid pressure may act outwardly upon said second crown portion and upon said internal valley portion and thereby tend to urge said first crown portion in a direction outwardly of said shaft.

Claim 5

Seal means for effecting a fluid seal between a shaft and wall means defining a space extending outwardly of said shaft and disposed to receive said seal means, said wall means including bottom wall means having first and second bottom wall portion means, said first bottom wall portion means defining with said shaft a first perpendicular depth, said second bottom wall portion means defining with said shaft a second perpendicular depth, said first perpendicular depth being less than said second perpendicular depth, said seal means comprising an O-ring of rubberlike material having an internal annular surface confronting said shaft and provided with first and second raised crown portions spaced apart from each other and including an internal valley portion therebetween and having an external annular surface confronting said bottom wall means and provided with third and fourth raised crown portions spaced apart from each other and including an external valley portion therebetween, said O-ring defining a first end section between said first and third crown portions and a second end section between said second and fourth crown portions, said first end section constituting a sealing section and having a free-state cross-sectional dimension between said first and third crown portions greater than said first perpendicular depth whereby said first end section is under a state of cross-sectional compression, said first crown portion directLy confronting and engaging said shaft and defining therewith a fluid seal, said second end section constituting a nonsealing section and having a free-state cross-sectional dimension between said second and fourth crown portions less than said second perpendicular depth, said second crown portion directly confronting said shaft and providing a nonsealing clearance therearound, said wall means also including downstream and upstream sidewall means, said first end section of said O-ring having end wall means facing said downstream sidewall means, said second end section of said O-ring having end wall means facing said upstream sidewall means, said second crown portion and said internal valley portion being exposed to fluid pressure whereby said fluid pressure may act outwardly upon said second crown portion and upon said internal valley portion and thereby tend to urge said first crown portion in a direction outwardly of said shaft.

Claim 6

The structure of claim 3, wherein said upstream sidewall means has first and second sidewall portion means, said first sidewall portion means facing and defining with said downstream sidewall means a first axial distance, said second sidewall portion means facing and defining with said downstream sidewall means a second axial distance, said first axial distance being less than said second axial distance, said O-ring having a free-state axial dimension between said third and fourth crown portions greater than said first axial distance whereby said third and fourth crown portions is under a state of axial compression.

Claim 7

The structure of claim 4, wherein said first and third crown portions respectively have free-state diameters greater than the diameters of said shaft and said first bottom wall portion means whereby said first end section of said O-ring between said shaft and said first bottom wall portion means is under a state of circumferential compression.

Claim 8

The structure of claim 3, wherein wall means includes backup washer means.