Lubrication system and planetary gear mechanism

1. A lubrication system for a planetary gear mechanism having a helical gear, the lubrication system comprising:

a first lubricating oil supply path disposed on one side of the helical gear in a direction along a rotation axis of the helical gear, the first lubricating oil supply path being formed toward a tooth surface of the helical gear;

a second lubricating oil supply path disposed on an other side of the helical gear, the second lubricating oil supply path being formed toward the tooth surface of the helical gear; and

a controller configured to switch discharge of lubricating oil to the tooth surface of the helical gear between the first lubricating oil supply path and the second lubricating oil supply path based on a rotation direction of the helical gear.

2. The lubrication system according to claim 1 , wherein

the first lubricating oil supply path includes a first discharge port from which lubricating oil is discharged,

the first discharge port is arranged so as to overlap with the tooth surface of the helical gear when viewed from the direction along the rotation axis,

the second lubricating oil supply path includes a second discharge port from which lubricating oil is discharged, and

the second discharge port is arranged so as to overlap with the tooth surface of the helical gear when viewed from the direction along the rotation axis.

3. The lubrication system according to claim 1 , further comprising:

a first shaft to which the helical gear is fixed as a sun gear; and

a plurality of planetary gears arranged around the helical gear, the plurality of planetary gears meshing with the tooth surface of the helical gear,

the first lubricating oil supply path including a plurality of first discharge ports from which lubricating oil is discharged, and

the plurality of first discharge ports being arranged in the first shaft.

4. The lubrication system according to claim 3 , wherein

the first discharge ports are arranged at equal intervals in a circumferential direction, and

a number of the first discharge ports is equal to or greater than a number of the planetary gears.

5. The lubrication system according to claim 3 , further comprising:

a planetary carrier rotatably supporting the plurality of planetary gears;

a housing rotatably supporting the planetary carrier; and

a second shaft fixed to the planetary carrier, the second shaft being arranged coaxially with the first shaft,

the second lubricating oil supply path including a second discharge port from which lubricating oil is discharged, and

the second discharge port being arranged in the second shaft.

6. The lubrication system according to claim 1 , further comprising:

a plurality of planetary gears arranged around the helical gear serving as a sun gear, the plurality of planetary gears meshing with the tooth surface of the helical gear;

a ring gear arranged around the plurality of planetary gears, the ring gear meshing with the plurality of planetary gears;

a third lubricating oil supply path disposed on the one side of the ring gear in the direction along the rotation axis, the third lubricating oil supply path being formed toward a tooth surface of the ring gear; and

a fourth lubricating oil supply path disposed on the other side of the ring gear, the fourth lubricating oil supply path being formed toward the tooth surface of the ring gear,

the controller being configured to switch discharge of lubricating oil to the tooth surface of the helical gear between the third lubricating oil supply path and the fourth lubricating oil supply path based on the rotation direction of the helical gear.

7. The lubrication system according to claim 1 , further comprising:

a sun gear;

a plurality of planetary gears arranged around the sun gear, the plurality of planetary gears meshing with the sun gear;

a planetary carrier rotatably supporting the plurality of planetary gears; and

a housing rotatably supporting the planetary carrier,

the helical gear being arranged around the plurality of planetary gears and meshing with the plurality of planetary gears, and

each of the first lubricating oil supply path and the second lubricating oil supply path being arranged in the housing.

8. A planetary gear mechanism having a helical gear, the planetary gear mechanism comprising:

a first lubricating oil supply path disposed on one side of the helical gear in a direction along a rotation axis of the helical gear, the first lubricating oil supply path being formed toward a tooth surface of the helical gear; and

a second lubricating oil supply path disposed on an other side of the helical gear, the second lubricating oil supply path being formed toward the tooth surface of the helical gear,

the first lubricating oil supply path including a first discharge port from which lubricating oil is discharged,

the first discharge port being arranged so as to overlap with the tooth surface of the helical gear when viewed from the direction along the rotation axis,

the second lubricating oil supply path including a second discharge port from which lubricating oil is discharged, and

the second discharge port being arranged so as to overlap with the tooth surface of the helical gear when viewed from the direction along the rotation axis,

the first discharge port facing toward the tooth surface of the helical gear along the rotation axis, and

the second discharge port facing toward the tooth surface of the helical gear along the rotation axis.