Abstract: The mechanical seal for movable joints of machines comprises at least two pairs of nonelastomer cylindrical rings (4, 5, 16) ground to each other with their faces and having their outer surfaces eccentrically displaced, and the rings themselves cooperate with an elastomer element (3, 15). One of the surfaces of the elastomer element (3, 15) (an outer or an inner one, respectively), has eccentrically arranged shoulders (17, 18, 19, 20) or borings (6, 7). The seal rings (4, 5, 16) have concentric cylindrical surfaces and are fitted on the shoulders (17,18,19,20) or in the borings (6,7).

Abstract: A sucker rod pump comprises a cylindrical housing (1) having a suction valve (3), a hollow plunger (2) with a discharge valve (18) capable of reciprocating along the cylindrical housing (1) and at least two stationary sealing devices (7) spaced from each other for a distance equal to or higher than the length of the hollow plunger (2) which interacts with each sealing device (7) interacting, in turn, with the hollow plunger (2) whose length (L) is equal to or higher than the sum of the distance (H) between the adjacent sealing devices (7) and the length (B) of one sealing device (7) but less than the sum of the double distance (H) between the adjacent sealing devices (7) and the length (B) of one sealing device (7).