Fan mounted on gearshaft

1. A cooling apparatus, comprising:

one or more fans, wherein each of the one or more fans comprises a fan blade assembly; and

one or more shafts, wherein each of the one or more shafts is operably coupled to an engine or a gearbox that rotates the shaft, and wherein each fan blade assembly of the one or more fans is disposed on one of the shafts

one or more cooling devices;

one or more primary cooling pathways, wherein each of the primary cooling pathways comprises at least one of the one or more fans, wherein each fan is in fluid communication with at least one of the one or more of the cooling devices;

each of the primary cooling pathways further comprise:

a shared connector in fluid communication with at least one of the one or more cooling devices;

a transition duct in fluid communication with the shared connector; and

a transition connector in fluid communication with the transition duct and with the at least one of the one or more fans.

2. The apparatus of claim 1 , wherein each of the one or more fans comprises a centrifugal fan, and axial-flow fan, or a cross-flow fan.

3. The apparatus of claim 1 , wherein each fan blade assembly is disposed on the one of the shafts without bearings.

4. The apparatus of claim 1 , comprising:

one or more cooling devices; and

one or more primary cooling pathways, wherein each of the primary cooling pathways comprises at least one of the one or more fans, wherein each fan is in fluid communication with at least one of the one or more of the cooling devices.

5. The apparatus of claim 3 , wherein the one or more cooling devices comprise a shared cooling device or a distributed cooling device.

6. The apparatus of claim 3 , wherein one of the one or more cooling devices is operably coupled to the one or more systems or components.

7. The apparatus of claim 6 , wherein the one or more systems or components comprise a main rotor gearbox, an accessory gearbox, one or more components driven by the accessory gearbox, a reduction gearbox, a hydraulic system, a lubrication system, or a temperature control system.

8. The apparatus of claim 1 , further comprising one or more secondary cooling pathways, wherein each of the secondary cooling pathways comprises a conduit in fluid communication with the transition duct of one of the primary cooling pathways and with one of the one or more cooling devices.

9. A method for cooling one or more systems or components, comprising:

providing one or more fans, wherein each of the one or more fans comprises a fan blade assembly; and

operably coupling each of one or more shafts to an engine or a gearbox that rotates the shaft, and wherein each fan blade assembly of the one or more fans is disposed on one of the shafts;

providing one or more cooling devices;

disposing one or more primary cooling pathways by:

disposing for each of the primary cooling pathways at least one of the one or more fans in fluid communication with at least one of the one or more of the cooling devices;

disposing a shared connector in fluid communication with the one or more cooling devices;

disposing a transition duct in fluid communication with the shared connector; and

disposing a transition connector in fluid communication with the transition duct and with the at least one of the one or more fans.

10. The method of claim 9 , wherein one or more fans comprise a centrifugal fan, and axial-flow fan, or a cross-flow fan.

11. The method of claim 9 , wherein the fan blade assembly is disposed on the shaft without bearings.

12. The method of claim 9 , further comprising:

providing one or more cooling devices; and

disposing one or more primary cooling pathways by disposing for each of the primary cooling pathways at least one of the one or more fans in fluid communication with at least one of the one or more of the cooling devices.

13. The method of claim 9 , wherein the one or more cooling devices comprise a shared cooling device or a distributed cooling device.

14. The method of claim 9 , further comprising operably coupling one of the cooling devices to the one or more systems or components.

15. The method of claim 14 , wherein the one or more systems or components comprise a main rotor gearbox, an accessory gearbox, one or more components driven by the accessory gearbox, a reduction gearbox, a hydraulic system, a lubrication system, or a temperature control system.

16. The method of claim 9 , further comprising disposing one or more secondary cooling pathways by disposing for each of the secondary cooling pathways a conduit in fluid communication with the transition duct of one of the primary cooling pathways and with one of the one or more cooling devices.

17. A rotorcraft, comprising:

a fuselage;

one or more engines coupled to the fuselage;

one or more fans coupled to the one or more engines, wherein each of the one or more fans comprises a fan blade assembly; and

one or more shafts, wherein each of the one or more shafts is operably coupled to an engine or a gearbox that rotates the shaft, and wherein each fan blade assembly of the one or more fans is disposed on one of the shafts;

one or more cooling devices;

one or more primary cooling pathways, wherein each of the primary cooling pathways comprises at least one of the one or more fans, wherein each fan is in fluid communication with at least one of the one or more of the cooling devices;

each of the primary cooling pathways further comprise:

a shared connector in fluid communication with at least one of the one or more cooling devices;

a transition duct in fluid communication with the shared connector; and

a transition connector in fluid communication with the transition duct and with the at least one of the one or more fans.

18. The rotorcraft of claim 17 , wherein each of the one or more fans comprises a centrifugal fan, and axial-flow fan, or a cross-flow fan.

19. The rotorcraft of claim 17 , wherein each fan blade assembly is disposed on the one of the shafts without bearings.