Automotive alternator having rectifier mounted on heatsink plate with cooling fins

An alternator for use in an automotive vehicle, the alternator comprising:

• a housing including a front frame and a rear frame;
• a cylindrical stator including an armature coil, the cylindrical stator being contained in the housing;
• a rotor rotatably disposed inside the cylindrical stator and supported in the housing;
• a rectifier mounted on the rear frame;
• a rear cover covering the rectifier, the rear cover being fixed to the housing;
• and
• a cooling fan for introducing cooling air into the housing through air inlets formed on a rear surface of the rear frame for cooling the rectifier, the cooling fan being connected to the rotor, wherein:
• the rectifier includes a minus heatsink plate on which minus rectifier elements are mounted and a plus heatsink plate on which plus rectifier elements are mounted, the minus heatsink plate being disposed to face the rear surface of the rear frame, the plus heatsink plate being disposed to face the rear cover, the minus heatsink plate and the plus heatsink plate forming a two-story structure in an axial direction;
• a lead terminal led out of each minus rectifier element extends in the axial direction of the rotor toward the rear cover;
• the minus heatsink plate includes cooling fins standing therefrom toward the rear cover in the axial direction and forming radial air passages between the cooling fins;
• the minus heatsink plate further includes second cooling fins standing therefrom toward the rear frame in the axial direction and forming second radial air passages between the second cooling fins;
• and
• the rear cover includes a plurality of radial openings that are open in a radial direction of the rotor and positioned radially outside of the cooling fins, so that the cooling air is introduced from the radial openings upon rotation of the cooling fan and flows through the radial air passages between the cooling fins and through the second radial air passages between the second cooling fins.

An alternator for use in an automotive vehicle, the alternator comprising:

• a housing including a front frame and a rear frame;
• a cylindrical stator including an armature coil, the cylindrical stator being contained in the housing;
• a rotor rotatably disposed inside the cylindrical stator and supported in the housing;
• a rectifier mounted on the rear frame;
• a rear cover covering the rectifier, the rear cover being fixed to the housing;
• and
• a cooling fan for introducing cooling air into the housing through air inlets formed on a rear surface of the rear frame for cooling the rectifier, the cooling fan being connected to the rotor, wherein:
• the rectifier includes a minus heatsink plate on which minus rectifier elements are mounted and a plus heatsink plate on which plus rectifier elements are mounted, the minus heatsink plate being disposed to face the rear surface of the rear frame forming an air passage therebetween, the plus heatsink plate being disposed to face the rear cover the minus heatsink plate and the plus heatsink plate forming a two-story structure in an axial direction;
• the rear surface of the rear frame contacts the minus heatsink plate at places where the air passage between the rear frame and the minus heatsink plate is not formed;
• the air passage between the rear frame and the minus heatsink plate is composed of a plurality of ditches formed on the rear surface of the rear frame, and an end of the minus rectifier elements is exposed to the ditches so that the rectifier elements are cooled by the cooling air flowing through the ditches;
• a lead terminal led out of each minus rectifier element extends in the axial direction of the rotor toward the rear cover;
• the minus heatsink plate includes cooling fins extending in the axial direction and forming radial air passages between the cooling fins;
• and
• the rear cover includes a plurality of radial openings that are open in a radial direction of the rotor and positioned radially outside of the cooling fins, so that the cooling air is introduced from the radial openings upon rotation of the cooling fan and flows through the radial air passages between the cooling fins and through the air passage between the minus heatsink plate and the rear surface of the rear frame.

An alternator for use in an automotive vehicle, the alternator comprising:

• a housing including a front frame and a rear frame;
• a cylindrical stator including an armature coil, the cylindrical stator being contained in the housing;
• a rotor rotatably disposed inside the cylindrical stator and supported in the housing;
• a rectifier mounted on the rear frame;
• a rear cover covering the rectifier, the rear cover being fixed to the housing;
• and
• a cooling fan for introducing cooling air into the housing through air inlets formed on a rear surface of the rear frame for cooling the rectifier, the cooling fan being connected to the rotor, wherein:
• the rectifier includes a minus heatsink plate on which minus rectifier elements are mounted and a plus heatsink plate on which plus rectifier elements are mounted, the minus heatsink plate being disposed to face the rear surface of the rear frame, the plus heatsink plate being disposed to face the rear cover, the minus heatsink plate and the plus heatsink plate forming a two-story structure in an axial direction;
• a lead terminal led out of each minus rectifier element extends in the axial direction of the rotor toward the rear cover;
• the rear cover includes radial openings that are open in a radial direction of the rotor and axial openings that are open in the axial direction of the rotor;
• and
• the minus heatsink plate includes at least first cooling fins standing from the minus heatsink plate toward a rear side of the alternator in the axial direction or second cooling fins standing from the minus heatsink plate toward a front side of the alternator in the axial direction, the first and the second cooling fins are positioned to face the radial openings of the rear cover, and the radial openings of the rear cover positioned radially outside of the first and second cooling fins.