Extrusion resistant hydrodynamically lubricated multiple modulus rotary shaft seal

A circular interference type extrusion resistant hydrodynamic seal for location within a housing defining a lubricant chamber and for dynamic sealing engagement with a relatively rotatable surface and for serving as a partition between the lubricant chamber and a contaminated environments and for serving to control seal deformation and interfacial contact force and thus regulate lubricant film thickness between the hydrodynamic seal and the relatively rotatable surfaces and having a lubricant end and an environment ends comprising:

• (a) a first circular ring-like seal section being composed of resilient material and having a predetermined modulus of elasticity;
• (b) a second circular ring-like seal section being composed of flexible material having a modulus of elasticity greater than said predetermined modulus of elasticity of said first circular ring-like seal section, said second circular ring-like seal section being connected integral with said first circular ring-like seal section and resisting pressure induced extrusion of said second circular ring-like seal section between the housing and the relatively rotatable surface;
• (c) a circular dynamic sealing lip being defined by said second circular ring-like seal section and projecting radially therefrom, said circular dynamic sealing lip having a peripheral sealing surface for dynamic sealing engagement with said relatively rotatable surface and defining a hydrodynamic geometry at one axial extremity thereof having an axially varying hydrodynamic edge for facing said lubricant chamber and for hydrodynamically wedging a film of lubricant between said dynamic sealing lip and said relatively rotatable surface, said predetermined modulus of elasticity of said first circular ring-like seal section minimizing deformation of said dynamic sealing lip and minimizing interfacial contact force of said dynamic sealing lip with the relatively rotatable surface to control the thickness of the film of lubricant between said peripheral sealing surface and the relatively rotatable surface and to minimize generation of heat upon movement of the relatively rotatable surface;
• (d) said first and second circular ring-like seal sections defining a circular end surface being oriented in substantially normal relation with said peripheral sealing surface and defining at least a portion of said environment end, said second circular ring-like seal section defining a non-planar flexible transitional heel geometry having a circular recess surface of concave cross-sectional configuration, said circular recess surface having circular intersection with said circular end surface radially remote from said peripheral sealing surface and having circular intersection with said peripheral sealing surface axially remote from said circular end surface;
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• (e) an abrupt axially nonvarying exclusionary geometry being defined at the opposite axial extremity of said dynamic sealing lip.

A circular interference type extrusion resistant hydrodynamic seal for location within a housing defining a lubricant chamber and for dynamic sealing engagement with a relatively rotatable surface and for serving as a partition between the lubricant chamber and a contaminated environment, and for serving to control seal deformation and interfacial contact force and thus regulate lubricant film thickness between the hydrodynamic seal and the relatively rotatable surface, comprising:

• (a) a first circular ring-like seal section being composed of resilient material and having a predetermined modulus of elasticity;
• (b) a second circular ring-like seal section being composed of flexible material having a modulus of elasticity greater than said predetermined modulus of elasticity of said first circular ring-like seal section, said second circular ring-like seal section being connected integral with said first circular ring-like seal section and resisting lubricant pressure induced extrusion of said second circular ring-like seal section between the housing and the relatively rotatable surface;
• (c) a circular dynamic sealing lip being defined by said second circular ring-like seal section and projecting radially therefrom, said circular dynamic sealing lip having a peripheral sealing surface for dynamic sealing engagement with said relatively rotatable surface and defining a hydrodynamic geometry at one axial extremity thereof having an axially varying hydrodynamic edge for facing said lubricant chamber and for hydrodynamically wedging a film of lubricant between said dynamic sealing lip and said relatively rotatable surface and having an abrupt axially nonvarving exclusionary geometry at the other axial extremity thereof, said predetermined modulus of elasticity of said first circular ring-like seal section minimizing deformation of said dynamic sealing lip and minimizing interfacial contact force of said dynamic sealing lip with the relatively rotatable surface to control the thickness of the film of lubricant between said peripheral sealing surface and the relatively rotatable surface and to minimize generation of heat upon movement of the relatively rotatable surface:
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• (d) said first and second circular ring-like seal sections defining a circular end surface being oriented in substantially normal relation with said peripheral sealing surface and defining an environment end of said hydrodynamic seal, said second circular ring-like seal section defining a non-planar flexible transitional heel geometry of concave cross-sectional configuration and having circular intersection with said circular end surface radially remote from said peripheral sealing surface and having circular intersection with said peripheral sealing surface axially remote from said circular end surface.

A circular interference type extrusion resistant hydrodynamic seal for location within a housing defining a lubricant chamber and a circular static surface and adapted for dynamic sealing engagement with a relatively rotatable surface and for serving as a partition between the lubricant chamber and a contaminated environment and for serving to control interfacial contact force of said seal with the relatively rotatable surface and thus control the lubricant thickness between said seal and the relatively rotatable surface, comprising:

• (a) a ring-like seal body of generally "C"-shaped cross-sectional configuration being composed of a flexible sealing material having a predetermined modulus of elasticity and defining a lubricant axial extremity and an environmental axial extremity, said ring-like seal body defining a circular body cavity being open toward said environment axial extremity of said ring-like seal body and defining radially inner and outer flexible seal body rims;
• (b) a circular dynamic sealing lip being defined by said ring-like seal body and having an axially varying hydrodynamic geometry at one axial end thereof for facing said lubricant chamber, and for hydrodynamically wedging a film of lubricant between said dynamic sealing lip and said relatively rotatable surface, said circular dynamic sealing lip further defining a peripheral sealing surface for sealing engagement with said relatively rotatable surface;
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• (c) a ring-like core of resilient sealing material being located within said circular body cavity and defining a substantially circular axial end surface for facing the contaminated environment, said ring-like core of resilient material having a modulus of elasticity less than said predetermined modulus of elasticity and permitting flexing of said flexible seal body rims toward one another for minimizing interfacial contact force of said circular dynamic sealing lip with the relatively rotatable surface, thus regulating the thickness of said film of lubricant.

A circular interference type extrusion resistant and lubricant film controlling hydrodynamic seal for location within a housing defining a lubricant chamber and a circumferential gland wall defining a circular static surface and a transverse gland wall for axial support of said extrusion resistant hydrodynamic seal, said circular interference type hydrodynamic seal being adapted for dynamic sealing engagement with the sealing surface of a relatively rotatable surface and for serving as a partition between the lubricant chamber and a contaminated environment, comprising:

• (a) a ring-like seal body having an outer circular seal body section being composed of a resilient sealing material having a predetermined modulus of elasticity and having an inner annular seal body section being integral with said outer annular seal body section and being composed of a resilient material having a greater modulus of elasticity than said predetermined modulus of elasticity, said inner and outer annular seal body sections defining a lubricant axial extremity and an environment axial extremity;
• (b) a circular hydrodynamic sealing lip being defined by said inner annular seal body section of said ring-like seal body and having an axially varying hydrodynamic geometry at one axial end of said circular dynamic sealing lip for facing said lubricant chamber and an axially non-varying exclusionary geometry at the other axial end thereof for facing the contaminated environment, said circular dynamic sealing lip further defining a generally cylindrical peripheral sealing surface for sealing engagement with said relatively-rotatable surface;
• (c) wherein said inner annular seal body section of said ring-like seal body further defining a non-planar flexible transitional heel geometry intersecting said environment axial extremity and said circular dynamic sealing lip and defining extrusion resistant seal geometry to minimize pressure induced extrusion of said seal between said housing and said relatively rotatable surface;
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• (d) means, comprising said greater modulus of elasticity of said second circular ring-like seal section than said predetermined modulus of elasticity of said first circular ring-like seal section for minimizing contact force of said dynamic sealing lip of said second circular ring-like seal section with said relatively rotatable surface and minimizing compression induced distortion of said hydrodynamic geometry of said circular dynamic sealing lip for controlling hydrodynamic wedging of said film of lubricant and controlling the thickness of the film of lubricant between said peripheral sealing surface of said dynamic sealing lip and said relatively rotatable surface.