GB1387480A - Energy transfer machine - Google Patents

Abstract

1387480 Circumferential flow turbines compressors and pumps GARRETT CORP 8 Aug 1972 [9 Aug 1971] 36998/72 Headings F1C and FIT A turbomachine comprises a housing enclosing a toroidal space containing a vaneless stator ring 42 defining an annular flow passage 46 extending about the machine axis 14, rotor blades 60 being disposed in the flow passage such that at least a major part of the inner edge 62 of each blade lies radially inwards of the centroid 98 of the flow passage cross-section and at least a major part of each blade outer edge 64 lies radially outwards of the centroid. The inlet duct 26 to flow passage 46 is oriented such that the absolute velocity of working fluid approaching rotor blades 60 is substantially normal to the direction of motion of the latter. The outlet duct 30 is oriented in alignment with the absolute velocity of working fluid entering the duct. The machine may be a turbine, compressor or pump using gas or liquid as the working fluid, the arrangement described being an air pump e.g. for an automobile emission control system. Air from inlet duct 26 flows in a helical path about annular passage 46, thus passing through rotor blades 60 several times in a radially inwards or outwards direction before leaving through outlet duct 30 at higher pressure. Ducts 26 and 30 are separated by a block 100 integrally formed with stator ring 42 and having an arcuate recess to permit passage of rotor blades 60, the base of the recess being flush with ring face 74 with which the blade tips sealingly co-operate. The machine housing is formed by end members 16 and 18 bolted together and between which is sandwiched intermediate member 32. End member 16 supports stator ring 42 via studs 44 and rotor shaft 22 via bearings 24. In the arrangement shown flow passage 46 is of constant cross-section throughout its circumferential extent but in modifications Figs.9 to 13 (not shown) the cross-section decreases from inlet to outlet by varying the shape of stator ring 42 and/or that of the housing members. In a further modification Figs.14 to 18 (not shown) the stator ring and intermediate housing member are integrally cast, the air inlet duct is of altered shape including flow dividing partitions (190), and a centrifugal dirt separator (194) is provided on the rotor shaft.