| 摘要 |
1,259,478. Piston rings. LINDE A.G. 14 Oct., 1969 [14 Oct., 1968], No. 50288/69. Heading F2T. A piston comprises a piston-rod 18 guided by a dry anti-friction material, e.g. P.T.F.E., bearing 17 and a head 1 having a number of guide rings 8 biased outwardly in grooves 5, means being provided for preventing further outward movement when a predetermined amount of wear of the rings has occurred. The rings are biased by gas pressure and springs 10 and may be made of P.T.F.E. The means preventing further outward movement may comprise shoulders 9 on the ring gengagings houlders 12 in the groove, Fig. 1, or the shoulders may be angled and the ring biased by a corrugated metal spring (28), Fig. 2 (not shown), a radial pressure balance groove (29) being provided. The shoulders on the ring may be in the form of a swaged on annular metal housing, Figs. 3, 4 (not shown), and the ring may have labyrinth grooves (53) at its working face, Fig. 4 (not shown). The shoulders may be replaced by axially extending pins which may have end pegs (61), Fig. 5 (not shown), and be insertable through radial channels (63) in the piston or the rings may have common pins, the pins being surrounded by either bushes (70) in the body of the ring, Fig. 6 (not shown), or a metal housing 7, 9 may be attached to the ring, Fig. 7. One ring 81 includes a sheet metal ring 85. Passages may be provided for the admission of cooling medium to the bearing 17. |
