Differential gear apparatus

A differential gear apparatus, comprising:

• a freely rotatable sun gear;
• a freely rotatable internal gear arranged on an outer circumference of the sun gear;
• a planetary gear meshed with the sun gear and the internal gear;
• a freely rotatable carrier supporting the planetary gear;
• a first shaft coupled to any one of the sun gear, the internal gear, and the carrier to be rotated in conjunction with it;
• a second shaft coupled to any other one of the sun gear, the internal gear, and the carrier to be rotated in conjunction with it;
• and
• a nut screwed into the first shaft or the second shaft, wherein
• the sun gear, the internal gear, and the planetary gear have profile shifted teeth of which addendum modifications are different at the positions in a flank width direction.

A differential gear apparatus, comprising:

• a freely rotatable first and second sun gears;
• a first planetary gear meshed with the first sun gear;
• a second planetary gear rotated with the first planetary gear and meshed with the second sun gear;
• and
• a carrier supporting the first and second planetary gears so that the first and second planetary gears freely rotate on their axes or orbit, and having a fitting hole at its rotation center part, wherein
• the carrier has fitting holes at positions bisected in a circumferential direction, and the planetary gears are supported in the bisected fitting holes.

A differential gear apparatus, comprising:

• a freely rotatable sun gear;
• a freely rotatable internal gear arranged on an outer circumference of the sun gear;
• a planetary gear meshed with the sun gear and the internal gear;
• and
• a carrier supporting the planetary gear so that the planetary gear freely rotates on its axis or orbits, wherein
• the carrier has a fitting hole at a position bisected in a circumferential direction, and the planetary gear is supported in the bisected fitting hole.

A method of processing a carrier of a differential gear apparatus comprising the steps of:

• connecting a first gear to a first shaft;
• connecting a second gear to a second shaft;
• arranging the second gear on an outer circumference of the first gear;
• processing a fitting hole at a position bisected in a circumferential direction, by:
• moving at least one of up and down or linearly a tool among three positions on one line of the carrier;
• coupling a plurality of carriers such that the bisected fitting holes are arranged concentrically;
• supporting a planetary gear in the bisected fitting holes;
• and
• meshing the first gear with the planetary gear.