Reciprocating Refrigeration Compressor and Method for Mounting a Reciprocating Refrigeration Compressor

Abstract

The compressor includes: a crankcase carrying a cylinder and a bearing hub which lodges a crankshaft; a valve plate closing one end of the cylinder; a piston reciprocating in the cylinder and driven by the rotation of the crankshaft; an electric motor having a stator affixed to the crankcase and provided with winding grooves and teeth, each tooth carrying a respective shoe, and a rotor affixed to the crankshaft and carrying magnet segments, stator, the rotor and the crankshaft are mounted in an indexed way, in order to present, in relation to one another, a relative positioning which produces, upon the stop of the electric motor and with the crankshaft and rotor being in the upper dead point condition of the piston, a cogging torque capable of taking the piston away from the upper dead point.

1 . A reciprocating refrigeration compressor, comprising:
 a crankcase carrying a cylinder and a bearing hub which lodges a crankshaft provided with an eccentric;   a valve plate closing one end of the cylinder;   a piston reciprocating in the interior of the cylinder and driven by a connecting rod coupled to the eccentric of the crankshaft;   an electric motor having a stator affixed to the crankcase and provided with a plurality of winding grooves intercalated with teeth, each tooth carrying a respective shoe, and a rotor affixed to the crankshaft and carrying magnet segments;   the reciprocating refrigeration compressor characterized in that, in the condition of upper dead point of the piston, at least one magnet segment of the rotor has its symmetry radial axis coinciding with the symmetry radial axis of a corresponding winding groove, said symmetry radial axes being positioned between the two stator teeth adjacent to said winding groove.   
     
     
         2 . The compressor, according to  claim 1 , characterized in that the stator, the rotor and the crankshaft present, in relation to one another, a relative positioning which produces, upon the stop of the electric motor and with the crankshaft and rotor assembly being in the upper dead point condition of the piston, a cogging torque capable of taking the piston away from the upper dead point. 
     
     
         3 . A method for mounting the reciprocating refrigeration compressor according to  claim 1 , the method being characterized in that it comprises the steps of:
 affixing the stator to the crankcase;   mounting the crankshaft in the bearing hub of the crankcase, rotatively locking the crankshaft with its eccentric in the upper dead point position of the piston;   affixing the rotor in the crankshaft in a relative angular positioning, in order to produce a cogging torque capable of taking the piston away from the upper dead point position.   
     
     
         4 . The method, according to  claim 3 , characterized in that the rotor is affixed to the crankshaft, with the symmetry radial axis of at least one magnet segment coinciding with the symmetry radial axis of a corresponding winding groove, said symmetry radial axes being positioned between the two teeth adjacent to said winding groove. 
     
     
         5 . The method, according to  claim 3 , characterized in that the rotor is affixed to the crankshaft with the diametral direction of the crankshaft, passing through the geometric center of the eccentric, coinciding with the symmetry radial axes of a magnet segment and of the corresponding winding groove.