GB882965A - Improvements in or relating to reciprocating movement synchronous compressors - Google Patents

Abstract

882,965. Reciprocating motors. USINES CHAUSSON S.A. DES. Feb. 16, 1960, No. 5490/60. Class 35. [Also in Groups XXVIII and XXXII] A reciprocating compressor motor, e.g. for a refrigerator, comprises two opposed permanent magnets 6, 7 constrained by springs 11, 12 and slidable within a substantially tubular magnetic core 4 which has an A.C. energizing coil 5 of the same width as a magnetic portion 9 that separates the magnets. The magnets have polepieces 8, 10 and the core has a non-magnetic liner 15. The core may be either solid or consist of axial laminations which may be spaced around the liner in four groups (Figs. 2 and 3, not shown). In one embodiment (Fig. 1, not shown), the armature assembly has a singleacting compressor, comprising a flexible cup piston in a cylinder, connected to each end and the springs are undertuned so that the resilient effect of the compressors brings the assembly to resonance at the A.C. supply frequency when on load. If the magnitude of the oscillations becomes excessive the compressor pistons strike spring-loaded flap valves which act as buffers. The device is enclosed in a casing to which the fluid is admitted at low pressure. In an alternative arrangement, Fig. 4, a double-acting compressor is fitted at one end only and exhausts within the casing 1 which thus contains fluid at a high pressure. The other end of the armature is connected to a piston 31 which operates in a virtually closed cylinder 24 and acts as an additional spring. The cylinder is connected to the inlet 2 via a small bore tube 32, and as the inlet pressure, and hence the pressure within the cylinder 24, decreases the effect of this " spring " is lessened and so is the natural frequency of vibration of the assembly. This was arranged to be above the supply frequency in this case, so it now gets closer to it and the amplitude of vibration increases; when great enough, valves 27, 28 are opened by the piston 31, high pressure fluid is admitted and the amplitude begins to drop. In practice the amplitude is thus maintained substantially constant regardless of the compression rate. The effect may be enhanced by an additional pump (Fig. 5, not shown) to exhaust the cylinder 24.