US 11,731,057 B2
System, method, and apparatus for power limited sky diving wind tunnel drive train/fan
Joseph F. Maida, Philadelphia, PA (US); and Arthur Armellini, Huntingdon Valley, PA (US)
Assigned to Maida Engineering, Inc., Philadelphia, PA (US)
Filed by Maida Engineering, Inc., Philadelphia, PA (US)
Filed on Sep. 7, 2020, as Appl. No. 17/13,800.
Application 17/013,800 is a continuation of application No. 16/373,608, filed on Apr. 2, 2019, granted, now 10,765,958.
Claims priority of provisional application 62/651,697, filed on Apr. 2, 2018.
Prior Publication US 2020/0406154 A1, Dec. 31, 2020
This patent is subject to a terminal disclaimer.
Int. Cl. A63G 31/00 (2006.01); F04D 27/00 (2006.01); G09B 9/00 (2006.01); F04D 29/063 (2006.01); F16H 57/04 (2010.01); F04D 19/00 (2006.01)
CPC A63G 31/00 (2013.01) [F04D 19/002 (2013.01); F04D 27/004 (2013.01); F04D 29/063 (2013.01); F16H 57/04 (2013.01); G09B 9/00 (2013.01)] 21 Claims
OG exemplary drawing
 
1. A flight simulator comprising:
a) a wind tunnel chamber comprising a first vertical flight chamber and a second vertical chamber communicatively coupled thereto via air flow conduits;
b) a nacelle disposed within the second vertical chamber of the wind tunnel chamber and including a ratio gearbox connected to a fan;
c) a motor disposed remote from the nacelle for powering the fan via a jackshaft and the ratio gearbox to rotate the fan at at least a threshold minimum speed sufficient to enable human flight within the first vertical flight chamber;
d) a variable frequency drive responsive to a control signal from a programmable logic controller to regulate the speed of the motor to: a) a first nonzero target motor speed which is not sufficient to cause the fan to rotate at at least the threshold minimum speed; or b) a range of second target motor speeds, all second target motor speeds in the range being greater than the first nonzero target motor speed and sufficiently high to cause the fan to rotate at at least the threshold minimum speed; or c) a third target motor speed of zero RPM indicative of an off condition;
wherein the variable frequency drive is programmed to operate the motor at nonzero target speeds only equal to or greater than said first nonzero target motor speed; and
wherein the variable frequency drive includes an electronic switch electrically connected to the programmable logic controller for selectively disabling, in response to a user operation or signal from the programmable logic, a low control voltage of power semiconductors of an output stage of the variable frequency drive, to thereby prevent the variable frequency drive from generating a torque required to rotate the motor, without activation of a high ampere main disconnect switch.