Low torque hydrodynamic lip geometry for bi-directional rotation seals

A hydrodynamic rotary seal for location by a machine component for dynamic sealing engagement with a relatively rotatable surface and serving as a partition between a first fluid of a lubricant supply and a second fluid, comprising:

• a static sealing surface forming a sealing interface with the machine component;
• a generally circular dynamic lip comprising:
• a first wave having a first multi-function edge, at least a portion of said first multi-function edge forming a first ramp section;
• a second wave having a second multi-function edge, at least a portion of said second multi-function edge forming a second ramp section,
• wherein said first and second ramp sections curve toward the relatively rotatable surface;
• an elongated dimple including a dimple flank having a generally convex curve-like profile when viewed in longitudinal transverse cross-section, said elongated dimple having a first side formed in part by said first ramp section and a second side formed in part by said second ramp section;
• and
• first and second dimple fillets, said dimple fillets having a generally concave curve-like profile when viewed in longitudinal transverse cross-section and having a sloping profile in the circumferential direction, said dimple fillets being substantially tangent to said dimple flank.

A family of compression-type hydrodynamic rotary seals for retaining a fluid, the seals of the type adapted to be subject to compression against a relatively rotatable surface and establish a contact footprint and contact pressure with the relatively rotatable surface when installed, the family comprising:

• a plurality of individual seals sized to fit varying equipment envelope constraints, some of said individual seals having a smaller cross-sectional size compared to other of said individual seals having a larger cross-sectional size;
• each of said individual seals having at least one hydrodynamic inlet establishing a rate of convergence with the relatively rotatable surface when installed, and producing hydrodynamic wedging action in response to relative rotation, wedging a film of the fluid into the contact footprint;
• the contact pressure of said individual seals varying as a function of said cross-sectional size, the contact pressure of said individual seals having a smaller cross-sectional size being higher than the contact pressure of said individual seals having a larger cross-sectional size;
• and
• said rate of convergence being more gradual for said individual seals of smaller cross-sectional size compared to said rate of convergence for said individual seals of larger cross-sectional size to compensate for the higher contact pressure of said individual seals having a smaller cross-sectional size.

A family of hydrodynamic rotary seals for retaining a fluid, the seals of the type adapted to be subject to compression against a relatively rotatable surface and establish a contact footprint and contact pressure with the relatively rotatable surface when installed, the family comprising:

• a plurality of individual seals sized to fit varying equipment envelope constraints, some of said individual seals having a smaller diameter compared to other of said individual seals having a larger diameter;
• each of said individual seals having at least one hydrodynamic inlet establishing a rate of convergence with the relatively rotatable surface when installed, and producing hydrodynamic wedging action in response to relative rotation, wedging a film of the fluid into the contact footprint;
• and
• said rate of convergence of said smaller diameter individual seals being substantially the same as said rate of convergence of said larger diameter individual seals.

A family of hydrodynamic rotary seals for retaining a fluid, the seals of the type adapted to be subject to compression against a relatively rotatable surface and establish a contact footprint and contact pressure with the relatively rotatable surface when installed, the family comprising:

• a plurality of individual seals sized to fit varying equipment envelope constraints, some of said individual seals having a smaller diameter compared to other of said individual seals having a larger diameter;
• each of said individual seals having at least one hydrodynamic inlet having a curvature and establishing a rate of convergence with the relatively rotatable surface when installed, and producing hydrodynamic wedging action in response to relative rotation, wedging a film of the fluid into the contact footprint;
• and
• at least part of said curvature of said smaller diameter individual seals being concave, and at least part of said curvature of said larger diameter individual seals being convex.