Rotor assembly, permanent magnet synchronous motor, electric compressor, air conditioning system, and vehicle

A rotor assembly comprising:

• a rotor body comprising:
• a rotor core for accommodating a permanent magnet,
• end plates, and
• at least one balance weight,
• wherein the end plates are arranged at two axial ends of the rotor core, respectively, and the at least one balance weight is disposed at a side of at least one of the end plates facing away from the rotor core;
• and
• at least one rotor rivet axially penetrating the rotor body to fix the rotor body into one piece;
• each of the at least one rotor rivet comprising a rod portion, a head portion, and a riveting portion;
• wherein the head portion and the riveting portion are located at two ends of the rod portion in a length direction of the rod portion, respectively,
• wherein:
• at least one of the at least one balance weight is a first balance weight having a rivet hole,
• the rivet hole has a first hole segment configured to engage with the rod portion and a second hole segment configured to engage with the riveting portion,
• the second hole segment has an expanded hole contour relative to the first hole segment, and
• the riveting portion being at least partially filled in the second hole segment.