Rotor assembly balancing using a park lock gear and balancing plate

An electric drive unit comprising:

• a rotating assembly comprising:
• a park lock gear, wherein the park lock gear comprises:
• a cylindrical body, wherein the cylindrical body forms an internal spline, wherein a plurality of balancing holes are defined axially through at least a portion of the cylindrical body;
• and
• a plurality of external teeth, wherein the plurality of external teeth extend radially outward from the cylindrical body, wherein the plurality of external teeth define a plurality of external tooth gaps, wherein the plurality of external teeth and the plurality of external tooth gaps are defined in a polar array about a center axis of the park lock gear;
• a rotor shaft, wherein the rotor shaft forms an external spline, wherein the internal spline meshes with the external spline;
• a rotor, wherein the rotor is configured to magnetically couple with a magnetic field causing the rotating assembly to rotate;
• a sensor rotor;
• and
• a balancing plate, wherein the park lock gear, the rotor, the sensor rotor, and the balancing plate are disposed radially outwards of and axially aligned with the rotor shaft, wherein the park lock gear, the rotor, the sensor rotor, and the balancing plate are affixed to and configured to rotate with the rotor shaft, wherein the rotor is disposed axially between the park lock gear and the balancing plate, wherein the park lock gear and the balancing plate are configured to balance the rotating assembly, wherein the park lock gear balances the rotating assembly by the plurality of balancing holes;
• a stator;
• and
• a park lock pawl, wherein the park lock gear is configured to and unlock the rotating assembly to and from the stator via the park lock pawl.

A method of assembling a rotating assembly, the method comprising:

• affixing a rotor to a rotor shaft;
• affixing a balancing plate and a sensor rotor to the rotor shaft;
• affixing a park lock gear to the rotor shaft;
• and
• axially drilling the park lock gear and the balancing plate to balance the rotating assembly, wherein the axially drilling forms a plurality of balancing holes,
• wherein the rotating assembly comprises the park lock gear, the rotor shaft, the rotor, the balancing plate, and the sensor rotor, wherein the park lock gear comprises:
• a cylindrical body, wherein the cylindrical body forms an internal spline, wherein the plurality of balancing holes are defined axially through at least a portion of the cylindrical body;
• and
• a plurality of external teeth, wherein the plurality of external teeth extend radially outward from the cylindrical body, wherein the plurality of external teeth define a plurality of external tooth gaps, wherein the plurality of external teeth and the plurality of external tooth gaps are defined in a polar array about a center axis of the park lock gear;
• wherein the rotor shaft forms an external spline, wherein the internal spline meshes with the external spline;
• wherein the rotor is configured to magnetically couple with a magnetic field causing the rotating assembly to rotate;
• and
• wherein the park lock gear, the rotor, the sensor rotor, and the balancing plate are disposed radially outwards of and axially aligned with the rotor shaft, wherein the park lock gear, the rotor, the sensor rotor, and the balancing plate are affixed to and configured to rotate with the rotor shaft, wherein the rotor is disposed axially between the park lock gear and the balancing plate, wherein the park lock gear and the balancing plate are configured to balance the rotating assembly, wherein the park lock gear balances the rotating assembly by the plurality of balancing holes.