Patent GB-772551-A (GB)
Title: Improvements in or relating to a synchronous oscillating refrigerant compressor
IPC: F04B39/12
Filed: 1955-01-10
Abstract: 772,551. Reciprocating electric motors. SOC.ANON. DES USINES CHAUSSON. Jan. 10, 1955 [Jan. 11, 1954], No. 709/55. Class 35. [Also in Groups XIII and XXVIII] In a refrigerant compressor of type having pistons carried on resilient blades oscillated electromagnetically, the parts depend into a tank 2 and are suspended resiliently from the cap 3 of the tank, the refrigerant flowing from the evaporator to the compressor suction passes through an oil separator and porous filter, the pistons are lubricated by oil drawn up from the bottom of the tank through porous elements by capillary action, and a part of the condensed refrigerant is returned to the discharge space of the compressor to cool the latter by evaporation. As shown, a rigid central plate 21 is suspended by springs 11, 12 from the end wall of cap 3 and carries upper and lower projections 22, 26 provided with shock-absorbing facings 24 and received with clearance in recesses 25, 26a in the cap end wall and the bottom of tank 2 respectively. Resilient blades 19, 20 are fixed to the upper part of plate 21 by bolts 18 and spacers 16, 17. Each blade carries a block 35, provided with two horizontal permanent magnets 39, 38 parallel to plate 21 and with unlike poles adjacent. U-shaped armatures 29, 30 are secured to plate 21 with their poles 29a, 29b, 30a, 30b opposite the ends of the permanent magnets and are energized by alternating current flowing through coils 31 ... 34 carried on the poles to oscillate the blocks 35 and hence the blades 19, 20. Blocks 35 carry loading washers 42 and the natural frequency of the blades 19, 20 and the parts carried thereby is less than the applied A,C. frequency so that the parts oscillate in synchronism. As the compressor starts up, the discharge pressure increases, which increases the natural frequency of the oscillated parts to approach the applied frequency to improve the power factor under load. The thickness of the poles of armatures 29, 30 is slightly more than the spacing between magnets 38, 39 so that when the compressor is inoperative a closed magnetic circuit is formed. The lower end of plate 21 carries the cylinder head 48 formed with two cylinders 47 in which work pistons 46 connected by resilient wires 45 to the lower end 43 of oscillated blocks 35. The outer ends of the cylinders are closed by flexible sheets 51 and the pistons have cupped packings engagement of which with the cylinder wall during the compression stroke is ensured by tapering ends 47a of the cylinder wall. Bolts 50 secure to the cylinder head porous elements 58, e.g. of sintered bronze, which dip into oil in the bottom of tank 2 and draw it up, the oil passing into the cylinder through capillary passages, not shown. Compressed gas passes from discharge space 59 through pipe 60 to the condenser and part of the condensate is returned to the space 59 through pipe 61 to evaporate therein and cool the compressor. Gaseous refrigerant from the evaporator flows through pipe 57, chamber 53 and pipes 52 to the compressor cylinders.' In chamber 53 it is filtered by passing through an element 56, e.g. of sintered bronze, and oil is trapped in a chamber 55 whence it flows through an aperture, not shown, into the bottom of tank 2.