Patent ID: 8257061

Claim:
A hermetic compressor with internal thermal insulation, comprising: a housing ( 1 ) internally carrying a cylinder block ( 2 ) in which is defined a compression cylinder ( 3 ), having one end closed by a valve plate ( 7 ) provided with a discharge orifice ( 7 a ) and a suction orifice ( 7 b ), said valve plate ( 7 ) having a rear face 7 d , facing cylinder block ( 2 ) and in which is mounted a suction valve ( 8 b ) and a front face ( 7 c ) against which is mounted a cylinder cover ( 5 , 10 ) internally defining a discharge chamber ( 5 a , 11 ) and in which the valve plate ( 7 ) externally carries a discharge valve ( 8 a ), characterized in that said compressor comprises a spacing duct ( 20 ) having one inlet end ( 21 ), hermetically mounted to the front face ( 7 c ) of the valve plate ( 7 ) and open to the discharge orifice ( 7 a ) of the valve plate ( 7 ) external to the suction orifice ( 7 b ) thereof, and an outlet end ( 22 ) hermetically mounted to the cylinder cover ( 10 ) and open to the interior of the discharge chamber ( 11 ), with the inlet end ( 21 ) of the spacing duct ( 20 ) presenting a cross-section area at least equal to that of the discharge orifice ( 7 a ), said spacing duct ( 20 ) defining a hermetic fluid communication between the interior of the compression cylinder ( 3 ) and the discharge chamber ( 11 ) through the discharge orifice ( 7 a ), said spacing duct ( 20 ) maintaining the cylinder cover ( 10 ) spaced from the valve plate ( 7 ) to provide an insulating chamber between said valve plate ( 7 ) and said cylinder cover ( 10 ) and by a value calculated so as to reduce the heat transfer from the gas in the discharge chamber to the valve plate ( 7 ) and defining, with the latter, an annular plenum around said spacing duct ( 20 ), the cross-section of the inlet end ( 21 ) of the spacing duct ( 20 ) circumscribing the discharge valve ( 8 a ).