Universal drive
A universal drive including a ring gear, a sun gear in which a sun gear axis is moveable relative to a ring gear axis of the ring gear, a gear train constituted by a series of gears configured to connect the sun gear and the ring gear to each other, a link mechanism connected to the sun gear and the ring gear in the state in which relative rotation therebetween is allowed such that a power transmission state between the sun gear and the ring gear is continuously maintained while accommodating a change in the inter-axis distance between the sun gear and the ring gear, a carrier installed so as to support a rotating shaft of a final gear engaged with the ring gear, and a sliding member located between at least one of the gears and the carrier.
1. A universal drive comprising:
a ring gear;
a sun gear having a sun gear axis moveable relative to a ring gear axis of the ring gear;
a gear train comprising a series of gears configured to connect the sun gear and the ring gear to each other;
a link mechanism connected to the sun gear and the ring gear so rotation between the sun gear and the ring gear is allowed such that a power transmission state between the sun gear and the ring gear is continuously maintained while accommodating a change in an inter-axis distance between the sun gear and the ring gear, the link mechanism being configured to support rotating shafts of the series of gears constituting the gear train;
a carrier configured to support a rotating shaft of a final gear engaged with the ring gear, among the gears constituting the gear train; and
a sliding member positioned between at least one of the gears constituting the gear train and the carrier such that the sliding member is slidable relative to the carrier.
2. The universal drive according to claim 1 , wherein:
the link mechanism comprises a first link and a second link rotatably connected to each other;
a joint gear has a rotating shaft configured to rotatably support the first link and the second link; and
the gear train comprises a first intermediate gear configured to connect the sun gear and the joint gear to each other, a second intermediate gear configured to connect the joint gear and a final gear to each other, the joint gear, and the final gear.
3. The universal drive according to claim 2 , wherein the sliding member is positioned at at least one of between the first intermediate gear and the carrier, between the joint gear and the carrier, and between the second intermediate gear and the carrier.
4. The universal drive according to claim 3 , wherein the sliding member is configured to be inserted into each end of at least one of a rotating shaft of the first intermediate gear, a rotating shaft of the joint gear, and a rotating shaft of the second intermediate gear.
5. The universal drive according to claim 4 , wherein the sliding member comprises a plastic washer inserted into an outer side of at least one of the rotating shaft of the first intermediate gear, the rotating shaft of the joint gear, and the rotating shaft of the second intermediate gear.
6. The universal drive according to claim 5 , wherein the sliding member has a plurality of oil recesses formed in a surface facing the carrier.
7. The universal drive according to claim 4 , wherein the sliding member comprises a thrust bearing inserted into at least one of the rotating shaft of the first intermediate gear, the rotating shaft of the joint gear, and the rotating shaft of the second intermediate gear.
8. The universal drive according to claim 2 , wherein:
the carrier includes a contact avoidance portion configured to avoid contact between the sun gear and the ring gear when the inter-axis distance between the sun gear and the ring gear changes; and
the sliding member is positioned at each end of the rotating shaft of a gear that does not abut the contact avoidance portion, among the gears constituting the gear train.
9. The universal drive according to claim 8 , wherein:
the carrier comprises a carrier outer and a carrier inner coupled to each other, the carrier outer and the carrier inner being configured to support the rotating shaft of the final gear on opposite sides;
the contact avoidance portion includes a contact avoidance recess formed in a surface of the carrier outer facing the gear train; and
the contact avoidance portion further includes a contact avoidance hole positioned on the carrier inner through which an input shaft connected to the sun gear extends.
10. The universal drive according to claim 9 , wherein the sliding member is positioned between each end of the second intermediate gear and the carrier.
11. The universal drive according to claim 9 , wherein a wheel hub is connected to the ring gear.
12. The universal drive according to claim 11 , wherein the ring gear and the wheel hub are concentrically spline-coupled to each other.
13. The universal drive according to claim 11 , wherein a carrier boss inserted into the wheel hub is integrally formed at the carrier outer, and a hub bearing is positioned between the carrier boss and the wheel hub.
14. The universal drive according to claim 2 , wherein the sun gear, the joint gear, and the final gear have a same number of teeth.
15. The universal drive according to claim 14 , wherein the link mechanism comprises a plurality of link mechanisms, and the gear train supported by the link mechanism includes a plurality of gear trains.