Differential device
In a differential device, side gears include: shaft portions; and intermediate wall portions each formed in a flat ring plate shape orthogonal to an axis of output shafts and integrally connecting between the shaft portions and toothing portions separated outward from the shaft portions in a radial direction of an input member, respectively. At least part of each intermediate wall portion is formed as a thin portion having an outside surface retreating axially inward from a backside of the tooting portion. A side wall portion of a cover portion integrally includes an outer-periphery-side side wall portion having an inside surface facing the backside of the toothing portion, and an inner-periphery-side side wall portion having an inside surface facing a backside of the intermediate wall portion. At least part of the inner-periphery-side side wall portion is formed thicker than the outer-periphery-side side wall portion and protrudes toward the thin portion.
1. A differential device comprising
an input member into which rotational force is input,
a differential gear support portion supported in the input member,
a differential gear supported on the differential gear support portion,
a pair of output gears meshing with the differential gear and connected to a pair of output shafts, respectively, and
a cover portion covering an axially output-side surface of at least one output gear of the output gears and rotating integrally with the input member,
wherein:
the at least one output gear includes:
a shaft portion connected to one output shaft corresponding to the one output gear,
a toothing portion meshing with the differential gear separated outward from the shaft portion in a radial direction of the input member, and
an intermediate wall portion integrally connecting between the shaft portion and the toothing portion, the intermediate wall portion including a retreating portion having an outer side surface retreating inwardly, in an axial direction of the output shafts, from an axially output-side surface of the toothing portion,
the cover portion includes a side wall portion rotatably supporting the axially output-side surface of the at least one output gear,
the side wall portion includes
an outer periphery-side side wall portion having an inner side surface facing the axially output-side surface of the toothing portion and
an inner periphery-side side wall portion having an inner side surface facing an axially output-side surface of the intermediate wall portion, and
at least part of the inner periphery-side side wall portion protrudes toward the retreating portion from the outer periphery-side side wall portion in the axial direction of the output shafts, and
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 differential gear support portion and a pitch cone distance, respectively.
2. The differential device according to claim 1 , wherein Z 1 /Z 2 ≥4 is satisfied.
3. The differential device according to claim 1 , wherein Z 1 /Z 2 ≥5.8 is satisfied.
4. The differential device according to claim 1 , wherein
a washer is interposed between opposing surfaces of the axially output side surface of the output gear and an inner side surface of the cover portion, the washer relatively rotatably connecting between the axially output side surface of the output gear and the inner side surface of the cover portion, and
a washer retaining groove retaining the washer is formed in at least one of the axially output side surface of the output gear and the inner side surface of the cover portion.
5. The differential device according to claim 4 , wherein the washer retaining groove is formed in the axially output side surface of the at least one output gear at the retreating portion.
6. The differential device according to claim 4 , wherein of the differential gear support portion, an intermediate shaft portion facing the retreating portions of the output gears is formed with a diameter smaller than that of another shaft portion.
7. The differential device according to claim 1 , wherein of the differential gear support portion, an intermediate shaft portion, facing the retreating portions of the output gears, is formed with a diameter smaller than that of another shaft portion.
8. The differential device according to claim 5 , wherein of the differential gear support portion, an intermediate shaft portion facing the retreating portions of the output gears is formed with a diameter smaller than that of another shaft portion.
9. A differential device comprising
an input member into which rotational force is input,
a differential gear support portion supported in the input member,
a differential gear supported on the differential gear support portion, and
a pair of output gears meshing with the differential gear and capable of rotating relative to each other, and
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 differential gear support portion and a pitch cone distance, respectively.
10. The differential device according to claim 9 , further comprising
a cover portion covering an outside of at least one output gear of the output gears and rotating integrally with the input member, wherein
a washer is interposed between opposing surfaces of an axially output side surface of the at least one output gear and an inner side surface of the cover portion, the washer relatively rotatably connecting between the axially output side surface of the output gear and the inner side surface of the cover portion, and
a washer retaining groove retaining the washer is formed in at least one of the axially output side surfaces of the output gear and the inner side surface of the cover portion.
11. The differential device according to claim 10 , wherein
the at least one output gear includes
a shaft portion connected to one output shaft corresponding to the one output gear,
a toothing portion meshing with the differential gear separated outward from the shaft portion in a radial direction of the input member, and
an intermediate wall portion integrally connecting between the shaft portion and the toothing portion, the intermediate wall portion including a retreating portion having an outer side surface retreating inwardly, in an axial direction of the output shafts, from an axially output side surface of the toothing portion, and
the washer retaining groove is formed in the axially output side surface of the output gear at the retreating portion.
12. The differential device according to claim 11 , wherein an intermediate shaft portion of the differential gear support portion, facing the retreating portions of the output gears, is formed with a diameter smaller than that of another shaft portion.
13. The differential device according to claim 10 , wherein
the at least one output gear includes
a shaft portion connected to one output shaft corresponding to the one output gear,
a toothing portion meshing with the differential gear separated outward from the shaft portion in a radial direction of the input member, and
an intermediate wall portion integrally connecting between the shaft portion and the toothing portion, the intermediate wall portion including a retreating portion having an outer side surface retreating inwardly, in an axial direction of the output shafts, from an axially output side surface of the toothing portion, and
an intermediate shaft portion of the differential gear support portion, facing the retreating portions of the output gears, is formed with a diameter smaller than that of another shaft portion.
14. The differential device according to claim 9 , wherein
the at least one output gear includes
a shaft portion connected to one output shaft corresponding to the one output gear,
a toothing portion meshing with the differential gear separated outward from the shaft portion in a radial direction of the input member, and
an intermediate wall portion integrally connecting between the shaft portion and the toothing portion, the intermediate wall portion including a retreating portion having an outer side surface retreating inwardly, in an axial direction of the output shafts, from an axially output side surface of the toothing portion, and
of the differential gear support portion, an intermediate shaft portion facing the retreating portions of the output gears is formed with a diameter smaller than that of another shaft portion.