GB1109533A - Sealing system for rotary piston machines - Google Patents

Abstract

1,109,533. Rotary-piston machines. NSU MOTORENWERKE A. G. May 19, 1966, No. 22304/66. Heading F1F. In a rotary-piston machine e. g. an I. C. engine, of the trochoidal n and n + 1 lobe type having a three-lobed piston (5), Fig. 1 (not shown), which is lodged in a two-lobed housing (3), a sealing system for the piston comprises a radial-sealing strip 9 situated in a groove (8) at each lobe or apex, a pair of axial-sealing rings 13, 14 located in either a common groove (15'), Fig. 2 (not shown), or concentric annular grooves (15, 16), within each end face, and two pairs of radially-orientated wedge-shaped sealing-strips 17, 17' abutting each end of each radial-sealing strip and the adjacent axial-sealing ring 13, the strips 17, 17' being lodged in grooves (8') that connect the grooves (8) to the grooves (15) or (15'). Sufficient clearance is provided between the various sealing strips and rings and the sides of the corresponding grooves in the piston to allow working fluid to fill an annular space 20 between each pair of axial-sealing rings and spaces within the grooves (8, 8') so as to press the strips and rings against the walls of the housing. The working fluid enters each of the spaces 20 from one or other of three working chambers (A, B, C) wherein the pressure is greatest by deflecting the ring 13 radially inwards. Each pair of rings 13, 14 may be replaced by a single ring (21), Fig. 4 (not shown), having a pair of axially-orientated flexible lips (22, 23) to define with a slot containing ring the annular space 20. Each of the radial-sealing strips 9 may be provided with a lateral, longitudinallyextending recess (26), Fig. 5 (not shown), containing a sealing-strip (27) that is pressed against the adjacent wall of the associated groove (8) by a leaf-spring 27a, the ring 13 being replaced by arcuate sealing strips (25) lodged in grooves (15a) lying between the grooves (8). The sealing system may be adapted to provide outwardly-sliding radial-vanes (9'), Figs. 6 and 7 (not shown), for a cylindrical rotary-piston (30) that is fixed to an eccentric rotatable-shaft (32), the vanes being provided with lateral sealing- strips (27'). Axial sealing is effected by a ring (14'), which is lodged in each end wall of the housing (3), and arcuate sealing-strips (25') lodged in the piston between the vanes. Each of the rings (14') may be replaced by a ring (14"), Fig. 8 (not shown), engaging with the shaft (32). The sealing system may be modified to effect sealing of a two-lobed piston (5'), Figs. 9 and 10 (not shown), arranged to rotate in a planetary manner relative to the housing, the rings 13 being replaced by arcuate sealing-strips (40, 41). The sealing system may be arranged to provide sealing for a rotary-piston machine of the trochoidal n and n + 1 lobe type having a two-lobed piston (50), Figs. 11 to 13 (not shown), which is lodged in a three-lobed housing (3), radial-sealing strips (54) being situated in slots (55) within the housing. Each of the strips (54) has a separate triangular portion at at least one end thereof to permit variations in the axial length of the strip. Axial-sealing rings (56, 57) are also situated in the housing with radially-orientated sealing-members (59) abutting the rings (56) and the ends of the radial-sealing strips.