Composite seals, seal structures and related methods

A method of forming a seal, the method comprising:

• forming a substantially annular first seal element including defining an upper body portion,
• an axial protrusion, and a neck portion between the upper body portion and the axial protrusion, including:
• forming the upper body portion with a radially outer lip, a radially inner lip, and first opposing inclined frustoconical surfaces that extend to and are contiguous with the neck portion;
• and
• forming the first opposing inclined frustoconical surfaces to define a first angle therebetween that is 60° or greater;
• forming the axial protrusion comprising:
• forming second opposing inclined frustoconical surfaces that extend to and are contiguous with an axial end of the axial protrusion;
• forming the second opposing inclined frustoconical surfaces to define a second angle therebetween that is 60° or greater and substantially similar to the first angle;
• forming third opposing inclined frustoconical surfaces that are contiguous the neck portion and extend away from the neck portion;
• and
• forming the third opposing inclined frustoconical surfaces to define a third angle therebetween that is 90° or greater;
• forming a substantially annular second seal element having a mouth portion, a throat portion and a recess portion;
• and
• disposing the axial protrusion in the recess portion in an interlocking manner;
• disposing the neck portion of the substantially annular first seal element in the throat portion of the substantially annular second seal element so that the neck portion complementarily abuts walls of the throat portion;
• and
• disposing the first opposing inclined frustoconical surfaces of the substantially annular first seal element in the mouth portion of the substantially annular second seal element so that the first opposing inclined frustoconical surfaces complementarily abut walls of the mouth portion.

A seal structure comprising:

• a first machine element;
• a second machine element, the first machine element and second machine element being configured to accommodate relative movement with respect to each other;
• a substantially annular cavity formed in the first machine element;
• a composite seal disposed in the substantially annular cavity, the composite seal comprising:
• a substantially annular first seal element comprising an upper body portion, an axial protrusion, and a neck portion located between the upper body portion and the axial protrusion, wherein:
• the upper body portion includes a radially outer lip, a radially inner lip, and first opposing inclined frustoconical surfaces extending to and contiguous with the neck portion, the first opposing inclined frustoconical surfaces defining a first angle therebetween;
• the axial protrusion includes second opposing inclined frustoconical surfaces extending to and contiguous with an axial end of the axial protrusion, the second opposing inclined frustoconical surfaces defining a second angle therebetween, and third opposing inclined frustoconical surfaces that are contiguous with the neck portion and extend away from the neck portion, the third opposing inclined frustoconical surfaces defining a third angle therebetween;
• the first angle and the second angle are substantially similar and 60° or greater;
• and
• the third angle is 90° or greater;
• and
• a substantially annular second seal element having a mouth portion, a throat portion and a recess portion, and wherein:
• the axial protrusion of the substantially annular first seal element is complementarily engaged with the recess portion of the substantially annular second seal element in an interlocking manner;
• the neck portion of the substantially annular first seal element complementarily abuts walls of the throat portion of the substantially annular second seal element;
• and
• the first opposing inclined frustoconical surfaces of the substantially annular first seal element complementarily abut walls of the mouth portion of the substantially annular second seal element.