GB1338269A - Seal assembly for a rotary piston machine - Google Patents

Abstract

1338269 Rotary piston machines AUDI NSU AUTO UNION A G and WANKEL GmbH 27 Oct 1971 [27 Oct 1970] 49833/71 Heading F1F A seal assembly in a rotary I.C. engine comprising a piston 12 rotatably mounted on an eccentric (5) Fig.1 (not shown) to which is secured a disc 11 partially closing a circular opening 20 in the piston side wall 12 for admitting coolant oil to the interior of the piston, the assembly being located about the periphery of the disc 11, comprises a retaining ring 15, an axially movable sealing ring 18 urged by an annular spring 21 against a radial surface of the disc 11 and keyed to the retaining ring 15 by tabs 22 and notches 18c, and a resilient annular seal 19 of e.g. rubber, arranged between the sealing ring 18 and the periphery of the opening 20, the retaining ring 15 forming a retainer for the remaining components of the assembly. The ring 15 is keyed by tongues 16 and slots 17 to the piston wall 12. In a modification Fig. 3 (not shown) the spring 21 acts on the ring 18 via the seal 19. In a further modification, the seal 19 is located in a peripheral groove (23) Fig.4 (not shown) in the ring 18, the base of the groove being lined with frictionreducing material, e.g. PTFE. In another arrangement, Fig.5 (not shown), the O-ring seal 19 in Fig.2 is replaced by hollow tubular ring (25) which is split laterally and lined with e.g. PTFE. Also the face of the ring 18 which abuts the disc 11 has a friction-reducing coating of e.g. carbon. In Fig.6, the resilient annular seal takes the form of a membrane 19b secured at its radially inner edge to the sealing ring 18b by a further ring 30, and sealingly engaging a surface 34 of the piston end wall 12 at its outer edge by means of a flange 33 secured to the retaining ring 15b. The latter has a number, e.g.3, of ribs 40 engaging projections 39 on the ring 18b to key the two rings together. The spring 21b is thus in three arcuate sections, and the ring 18b is retained axially by a sheet metal ring 37 secured to ring 15b.