GB187604A - Improvements relating to refrigerating machines - Google Patents

Abstract

187,604. Kucher, A. A. Oct. 22, 1921, [Convention date]. Refrigerating, compression machines jor. -The electric driving- motor 7 and the compressor 6 of a small machine are located within a condensing- chamber 3 formed 'by a casing 2 mounted on a base 1, the electric and fluid connections being disposed in the base so that the casing 2 may be readily removed and rendered fluid-tight when in place. The compressor is of the rotary type and is supported on an inner casing 15 enclosing the motor. Provision is made for discharging lubricant and refrigerant which may collect in the motor casing, for controlling the expansion valve by a float member, and for separating the lubricant from the refrigerant. The casings 2, 15 are bolted to the base member 1, rubber packing rings 19, 18 being located in grooves in the base to secure tight joints. The cooling-coil 10 in the gas chamber 3 is connected to radial passages in the base through which water or other cooling- liquid is supplied and discharged, and similar radial passages 49 are provided for the motor leads 50, which are connected to terminals 53 carried by screwed plugs 54, and are passed through insulating material 60 in a recess 58 in the base. The laminated field magnet structure 74, of the motor, supporting the field winding 75, is forced into position within longitudinal ribs 77 integral with the casing 15, the winding 75 being impregnated with or embedded in a body of insulating material 76 such as bakelite to protect it from the action of the refrigerant or lubricant. The evaporator comprises a coil 39, connected at 40 to the expansion valve 9, and a chamber 177 formed of two parts bolted together. The upper part 176 of this chamber is attached to a T-piece 184, one branch of which is screwed into the base for support, while the other branch is connected to a passage 45 in the base in communication with the compressor inlet 88 by a pipe 42. The passage 45 also communicates with the interior of the motor casing through a non-return valve 48 comprising a spring pressed ball seating in an aperture in a cap 35. When the compressor is working it withdraws any fluid in the motor casing through this valve into the inlet pipe 42, while when the compressor is stopped the pressure set up in the evaporator closes the valve to prevent entrance of fluid into the motor casing. The expansion valve stem 145 is pivoted to a lever 137 attached to a hollow ring 135 floating in the liquid in the outer casing, the valve thus being controlled automatically. The separator comprises a serpentine tube 150, Fig. 5, set concentrically with the float ring 135 and having one end 151 open below the normal level B-B of the condensed refrigerant and the other end connected with the valve casing. The lower bends of the tube are connected by branches 157 to a tube 159 sloping to one end 160 open below the normal level A-A of the lubricant and the upper bends are provided with apertures 156 to equalize the pressure. The refrigerant flows through the serpentine tube to the valve while the lubricant descends through the branches to the tube 159. The arrangement described is suitable when ethyl chloride is used as the refrigerant and a heavier substance such as glycerine is used as the lubricant. When the lubricant is lighter than the refrigerant the serpentine tube is arranged with its open end downwards, and the lubricant passes upwards through branch pipes at the top bends. The compressor comprises a rotor 63, Figs. 8, 9, keyed to the motor shaft 62 and provided with radially movable vanes 107, 108, the vane 107 being pivotally connected or keyed by a pin 112 to a ported sleeve 97 which thus rotates with the member 63. The cylinder casting is provided with inlet and outlet passages 88, 91 separated longitudinally and communicating with the interior of the sleeve by elongated ports, 94, 95 in the casting and ports 99, 100 in the sleeve. A check valve 8, Fig. 1, fitted at the outlet of the compressor, comprises two valve members 128, Fig. 2, connected by a spring 131. The motor shaft 62 has a reduced lower end 65 and is provided with a step bearing comprising a collar 70 attached to the shaft and a loose collar 71. An intermediate bearing in the upper part 81 of the motor casing is provided with packing 82, and a deflector 85 is attached to the shaft above the motor to deflect oil on to the wall of the casing away from the motor. The upper bearing is formed by an extension 164, Fig. 9 of the compressor casting. Oil is supplied under the pressure of the condenser chamber to a pocket 171 above the upper bearing by means of a pipe 168, Fig. 1, whose open end dips into the oil in the condenser chamber. From the pocket 171 the oil flows through passages 172, 173, Fig. 9, to the compressor, and then through a groove 190 and inclined passage 196 in the shaft 62 to a cup 72 around the bottom bearing, whence it escapes into the motor casing and is exhausted through the valve 48. The machinemay be fitted to the top of a refrigerator, and may be controlled thermostatically.