Rotational drive unit for a fan

A rotational drive unit comprising:

• an input rotatable about a first axis of rotation, the input configured to be driven by a power source in a single rotational direction;
• a first shaft in operable communication with the input and configured to rotate in a first direction;
• a second shaft in operable communication with the input and configured to rotate in a second direction opposite the first direction;
• an output rotatable about a second axis of rotation;
• a clutch assembly in operable communication with the first shaft, the second shaft, and the output, wherein the clutch assembly is operable in a first configuration in which force is transmitted between the first shaft and the output, and a second configuration in which force is transmitted between the second shaft and the output;
• and
• wherein the clutch assembly includes a first clutch pack in operable communication with and extending between the first shaft and the output, and wherein the clutch assembly includes a second clutch pack in operable communication with and extending between the second shaft and the output.

A rotational drive unit for a fan comprising:

• a housing;
• an input rotatable with respect to the housing about a first axis of rotation, wherein the input is rotatable in only a first direction;
• a first shaft driven by the input and configured to rotate with respect to the housing in the first direction;
• a second shaft driven by the input and configured to rotate with respect to the housing in only a second direction opposite the first direction;
• an output rotatable with respect to the housing about a second axis of rotation;
• a first clutch assembly in operable communication with the first shaft and the output, wherein the first clutch assembly is operable in an engaged configuration in which force is conveyed between the first shaft and the output, and a disengaged configuration in which force is not conveyed between the first shaft and the output;
• a second clutch assembly in operable communication with the second shaft and the output, wherein the second clutch assembly is operable in an engaged configuration, in which force is conveyed between the second shaft and the output, and a disengaged configuration, in which force is not conveyed between the second shaft and the output;
• and
• wherein the first shaft and the second shaft are coaxial.