Joint sealing structure

In a joint (10) including a first member (11) defining a cylindrical axially outwardly opening recess (15) having an axially outer surface (17) and a radially inner, circumferential surface (20), a second member (14) adjacent said first member and defining a sealing surface (18) confronting said recess, said members being associated to have relative rotational movement about the axis of the recess and relative movement toward and from each other along said axis, an improved sealing structure (21) in said recess movably sealing said members, comprising:

• an annular seal (23) having a radially outer base portion (29) received coaxially in said recess (15), an annular sealing portion (28) defining a lip (31) sealingly engaging said confronting sealing surface (18), and a flexible connecting portion (30) extending between said base portion (29) and sealing portion (28) for movably supporting said sealing portion;
• a flexible annular diaphragm (22) having a radially outer base portion (25) received coaxially in said recess (15) axially outwardly of said seal base portion and in sealing engagement with said circumferential surface (20) of said recess, a stiffener portion (26) operatively connected to said seal sealing portion (28) and defining an axially outer portion (33) exposed axially outwardly of said seal sealing portion (28), and said axially flexible connecting portion (27) extending between said diaphragm base (25) and sealing portion (28) axially outwardly of said seal connecting portion (30);
• and
• spring means (24) coaxially in said recess and acting between said first member and said stiffener portion to urge said lip into maintained movable sealed engagement with said confronting surface.