Differential device
In a differential device including: an input member capable of being joined to a carrier supporting a plurality of planetary gears via a plurality of first shafts that respectively support the plurality of planetary gears; a differential gear supported on the input member via at least one second shaft and being able to rotate and revolve; and a pair of output gears each meshing with the differential gear, the input member includes a plurality of recessed portions on a wall of the input member facing the carrier, the plurality of recessed portions being able to be respectively fitted with the plurality of first shafts and being each arranged at a position deviated in a peripheral direction of the input member with respect to the at least one second shaft. Accordingly, deterioration in durability of a differential case due to formation of the recessed portions is suppressed.
1. A differential device comprising:
an input member capable of being joined to a carrier supporting a plurality of planetary gears via a plurality of first shafts that respectively support the plurality of planetary gears;
a differential gear supported on the input member via at least one second shaft and being able to rotate with respect to the input member and revolve around a rotation center of the input member; and
a pair of output gears each meshing with the differential gear,
wherein the input member includes a plurality of recessed portions on a wall of the input member facing the carrier, the plurality of recessed portions being able to be respectively fitted with the plurality of first shafts and being each arranged at a position deviated in a circumferential direction of the input member with respect to each at least one second shaft,
wherein
d
2
/
PCD
≦
3.36
·
(
1
z
1
)
2
3
·
sin
(
tan
-
1
z
1
z
2
)
is satisfied, and
Z 1 /Z 2 >2 is satisfied, where Z 1 , Z 2 , d 2 and PCD denote the number of teeth of each of the output gears, the number of teeth of the differential gear, a diameter of the second shaft and a pitch cone distance, respectively.
2. The differential device according to claim 1 , wherein
the pair of output gears each includes a shaft portion connected to a corresponding one of a pair of output shafts, and
the input member includes: a boss portion concentrically surrounding the shaft portion; and a side wall portion connected to the boss portion and including an outer side surface that is a flat surface orthogonal to the output shafts.
3. The differential device according to claim 1 , wherein the plurality of recessed portions are each arranged at a position deviated in the peripheral direction of the input member with respect to a welding portion joining the carrier and the input member to each other.
4. The differential device according to claim 2 , wherein
the plurality of recessed portions are each arranged at a position deviated in the peripheral direction of the input member with respect to a welding portion joining the carrier and the input member to each other.
5. The differential device according to claim 1 , wherein Z 1 /Z 2 ≥4 is satisfied.
6. The differential device according to claim 1 , wherein Z 1 /Z 2 ≥5.8 is satisfied.
7. A differential device, comprising:
an input member including one cover portion and an other cover portion capable of being joined to the one cover portion, the one cover portion including a carrier main body part and a wall portion that is formed integrally with the carrier main body part, and the carrier main body part being able to be joined to a carrier cover supporting one end portion of each of a plurality of first shafts that respectively support a plurality of planetary gears;
a differential gear supported on the input member via at least one second shaft and being able to rotate with respect to the input member and revolve around a rotation center of the input member; and
a pair of output gears each meshing with the differential gear,
wherein the one cover portion includes a plurality of recessed portions each capable of being inserted with the other end portion of each of the plurality of first shafts, and
the plurality of recessed portions are each arranged to be deviated in a circumferential direction of the input member with respect to each at least one second shaft.
8. The differential device according to claim 7 , wherein
the pair of output gears each includes a shaft portion connected to a corresponding one of a pair of output shafts, and
the one cover portion and the other cover portion each include: a boss portion concentrically surrounding the shaft portion; and a side wall portion connected to the boss portion and including an outer side surface that is a flat surface orthogonal to the output shafts.
9. The differential device according to claim 7 , wherein
d
2
/
PCD
≦
3.36
·
(
1
z
1
)
2
3
·
sin
(
tan
-
1
z
1
z
2
)
is satisfied, and
Z 1 /Z 2 >2 is satisfied, where Z 1 , Z 2 , d 2 and PCD denote the number of teeth of each of the output gears, the number of teeth of the differential gear, a diameter of the second shaft and a pitch cone distance, respectively.
10. The differential device according to claim 9 , wherein Z 1 /Z 2 ≥4 is satisfied.
11. The differential device according to claim 9 , wherein Z 1 /Z 2 ≥5.8 is satisfied.