IE41316B1 - Counterbalanced fixed stroke piston machines - Google Patents

Abstract

1471447 Balancing: compressors A BRAUN 29 April 1974 [30 April 1973 (2)] 18695/74 Heading F1M and F1N To counterbalance the reciprocating parts of a fixed stroke reciprocating piston machine, a piston is connected to or forms part of a first or second member both of which reciprocate along the longitudinal axis of the associated cylinder and the two members are inter-connected by either racks and pinions or pivoted levers so that their movements are 180 degrees out of phase. The first member is connected by a connecting rod to the crank of a crank-shaft which has a counterbalancing portion for counterbalancing at least the crank. The machine may be an engine but the described embodiments are compressors. In a first embodiment Fig. 5 a compressor has two pistons 124, 132 inter-connected by parts 133, 138, 139 and the piston 124 is connected to a crank-shaft 72 having a balancing portion 75 by a rod 67. A second counterbalancing member 141 moves oppositely to the pistons 124, 132 by being connected to the part 133 by outer and inner racks 48, 49 and 134, 136 of a mechanism 141 engaging two pinions 34, 36 which are mounted on stationary shafts. The outer racks 48, 49 are interconnected together by a pair of plates 51, (52) having slots through which the pinions' shafts extend to permit reciprocation of the plates 51 (52). Inlet and outlet, valves 127, 142 and 128, 143 are located at the outer ends of cylinders 122 and 129. In an alternative but similar arrangement (not shown) a shaft extends upwardly from a piston and carries a mechanism similar to 141 at its upper end. The piston divides the cylinder into upper and lower compression chambers and the outlet of the upper chamber is connected to the inlet of the lower chamber via an intercooler to provide two stage compression. Another two stage compressor Fig. 7 has a first piston 216 connected to a part 258 and a second piston 214 connected by a shaft 229 and a similar rack and pinion mechanism to 141 to the first piston 216. A crank-shaft 272 is driven by an electric motor 277 and the outlet valve 221 of a first stage compression chamber 217 is connected via an intercooler 226 to the inlet 222 of a second stage compressor chamber 218. The piston 216 maybe replaced in another alternative construction by a wall extending across the cylinder to define with the lower face of piston 214 a first stage compression chamber. Furthermore a second wall maybe spaced below this wall to define an intermediate, ventilated chamber which prevents lubricant or fumes from passing into the compression chambers from the lower parts of the compressor. As an alternative to the racks and pinions shown in Fig. 7 the piston 216 maybe connected to the shaft 229 by a pair of intermediately pivoted levers 301, 302 Fig. 11 whose inner and outer ends are connected by pins and links to the shaft 229 and piston 216 respectively. [GB1471447A]