System for transporting lubricating oil in a compressor

System for transporting lubricating oil in a compressor, comprising:

• a housing (8);
• an electric motor comprising a rotor (1) and a stator (2),
• the rotor (1) comprising at least one inner wall (11);
• an oil pump (6) and an oil reservoir (7) arranged inside the housing (8);
• a rotary shaft (3) as an integral part of the electric motor;
• a compressor block (4) capable of housing, at least partially, the rotary shaft (3);
• the rotary shaft (3) supported by at least one radial bearing (5a, 5b);
• the rotary axis (3) comprising a lower region (31), an upper region (32) and a rotating surface (33);
• characterized in that the rotating shaft (3) has at least one concavity (35) that extends over part of the rotating surface (33) in contact with the internal surface (11) of the rotor (1) and at least one restrictor hole (34) which communicates with the internal region of the rotating shaft (3) and with the concavity (35);
• the rotor (1) comprises a circumferential channel (12) and at least one radial channel (13) extending through the inner wall (11) of the rotor (1);
• the radial channel (13) is arranged around the circumferential channel (12);
• said circumferential channel (12) and the radial channel (13) communicating with the concavity (35);
• the circumferential channel (12), the radial channel (13) and the concavity (35) transport oil for cooling the upper part of the rotor (1) and the stator (2).