Automatic two-mode high reduction power transmission system

A power transmission system comprising:

• a first device configured to deliver a first input and to receive a second output;
• a second device configured to deliver a second input and to receive a first output;
• a first planetary gear set connected, directly, to the first device;
• a second planetary gear set connected with the second device;
• a first freewheel mechanism connected between the second device and at least one of the first planetary gear set or the second planetary gear set;
• and
• a second freewheel device connected between the second device and the second planetary gear set;
• wherein the power transmission system is configured to:
• operate in a first mode having a first speed ratio, wherein the first device delivers a first input through a first power flow that results in a first output supplied to the second device, the first power flow directed through the first planetary gear set, the second planetary gear set, and the second freewheel mechanism;
• and
• operate in a second mode having a second speed ratio different than the first speed ratio, wherein the second device delivers a second input through a second power flow that results in a second output supplied to the first device, the second power flow directed through the first freewheel mechanism, the first planetary gear set and the second planetary gear set.

A power transmission system comprising:

• a first device configured to deliver a first input and to receive a second output;
• a second device configured to deliver a second input and to receive a first output;
• a sun gear connected, directly, with the first device;
• a set of first planet gears meshing with the sun gear;
• a set of second planet gears each one of which is connected to one planet gear in the first set of planet gears;
• a carrier carrying both the first and second sets of planet gears;
• a first ring gear meshing with the first set of planet gears;
• a second ring gear meshing with the second set of planet gears;
• a first freewheel mechanism connected between the second device and the carrier;
• and
• a second freewheel mechanism connected between the second device and the second ring gear;
• wherein the power transmission system is configured to:
• operate in a first mode having a first speed ratio, wherein the first device delivers a first input through a first power flow that results in a first output supplied to the second device, the first power flow directed through, in order, the sun gear, the first set of planet gears, the second set of planet gears, the carrier, and the second freewheel mechanism;
• and
• operate in a second mode having a second speed ratio different than the first speed ratio, wherein the second device delivers a second input through a second power flow that results in a second output supplied to the first device, the second powerflow directed through, in order, the first freewheel mechanism, the carrier, the first set of planet gears, and the sun gear.