Patent ID: 8360761

Claim:
A fixation arrangement for an oil pump in a refrigeration compressor of the type which comprises: a shell ( 1 ) inferiorly defining an oil sump ( 3 ) and carrying: a cylinder block ( 2 ) in which is journalled a crankshaft ( 4 ) having a lower portion ( 4 a ) projecting downwards from the cylinder block ( 2 ); an electric motor rotor ( 6 ) formed by a stack of annular laminations defining an axial central hole ( 6 a ) having an upper hole portion, inside which is fitted and affixed the lower portion ( 4 a ) of the crankshaft ( 4 ), and a lower hole portion ( 6 b ); an oil pump ( 10 ) comprising a tubular sleeve ( 20 ), superiorly mounted to the rotor ( 6 ) and inferiorly immersed in the oil sump ( 3 ), and a stationary pump shaft ( 30 ) internal to the tubular sleeve ( 20 ) and defining an annular gap with the inner wall of the latter, and having a lower end ( 31 ) supported by one of the parts of the shell ( 1 ) and cylinder block ( 2 ), characterized in that it comprises at least one retention element ( 40 ) disposed around the tubular sleeve ( 20 ) and which is radially and axially locked thereto, the retention element ( 40 ) having a radially outer locking portion ( 41 ), which is seated and radially forced against a respective and confronting circumferential extension ( 6 c ) defined between two consecutive annular laminations, so as to axially lock the tubular sleeve ( 20 ) to the rotor ( 6 ).