Power drive unit

Claim 2

A power drive unit for imparting two-directional drive to a thrust reverser mechanism with different torque demands in different cycles of operation including low torque and high speed in a deploy cycle and high torque and low speed in a stow cycle comprising, a two-direction variable displacement hydraulic motor with a displacement-varying means, a control cylinder having a piston connected to said displacement-varying means, a first circuit connected to said motor and including a valve for controlling the direction and volume of hydraulic flow to the motor and providing the same full rate of flow to said motor at the beginning of each of said cycles, and a second circuit connected to said control cylinder and including valve means operable independently of said valve for establishing the position of the piston in the cylinder at the beginning of each cycle to control the position of said displacement-varying means and have a minimal motor displacement for starting the deploy cycle and a maximum displacement for starting the stow cycle.

Claim 3

A power drive unit as defined in claim 1 including a control member for positioning of said valve, and feedback mechanism acting on said control member and responsive to operation of said motor to move said valve to a reduced flow position.

Claim 4

A power drive unit as defined in claim 2 and including a hydraulically-operated power cylinder for positioning of said control member to establish the direction of operation of the motor.

Claim 5

A power drive unit as defined in claim 3 wherein said power cylinder includes a differential area piston, means including a first valve for applying fluid pressure at all times during operation to the lesser area of the piston, and means including a second selectively operable valve for applying fluid pressure to the larger area of the piston.

Claim 6

A power drive unit as defined in claim 1 wherein said control cylinder piston has two different positions under the control of said valve means.

Claim 7

A power drive unit as defined in claim 1 wherein said control cylinder piston has three different positions under the control of said valve means.

Claim 8

A power unit for imparting two-directional drive to a mechanism with a low torque drive demand drive in one direction and a higher torque lower speed drive in the other direction including a two-directional motor with displacement-varying means, and a control cylinder for positioning of the displacement-varying means with the latter means spring-urged to one displacement setting, the improvement comprising, means including a first valve for selectively supplying pressure fluid to said control cylinder to move said displacement-varying means to a second displacement setting, means including a second valve for controlling the volume and direction of pressure fluid flow through the motor, control means for interrelating the movement of said first and second valves including a control link pivotally connected to both said first and second valves, and feedback mechanism responsive to motor operation for control of the position of said second valve.

Claim 9

A power unit for imparting two-directional drive to a mechanism with a low torque drive demand drive in one direction and a higher torque lower speed drive in the other direction including a two-directional motor with displacement-varying means, and a control cylinder for positioning of the displacement-varying means with the latter means spring-urged to one displacement setting, the improvement comprising, means including a first valve for selectively supplying pressure fluid to said control cylinder to move said displacement-varying means to a second displacement setting, means including a second valve for controlling the volume and direction of pressure fluid flow through the motor, control means for interrelating the movement of said first and second valves including a control link pivotally connected to both said first and second valves, and feedback mechanism responsive to motor operation for control of the position of said second valve.

Claim 10

A power unit comprising, a two-directional axial piston motor, an adjustable swash plate for controlling the stroke of the motor pistons, a control cylinder for positioning of said swash plate and including means to normally urge the swash plate to a relatively small displacement setting to establish a relatively high speed-low torque operation of the motor, a fluid circuit including a first valve for selectively supplying fluid to said control cylinder to move said swash plate to a second larger displacement setting to establish a relatively high torque-low speed operation of the motor, said fluid circuit including a first flow-regulating valve and a second valve in series for controlling the supply of pressure fluid to the motor, said fluid circuit including a return line from the motor and a second flow regulating valve for regulating the flow from the motor, said second flow-regulating valve permitting a greater rate of flow than the first flow-regulating valve, and a flow connection between the downstream sides of the flow regulating valves including a check valve preventing flow toward the second regulating valve, control means for said first and second valves including a control link pivotally connected thereto, and feedback mechanism responsive to motor operation for control of the position of the second valve.

Claim 11

A power unit comprising, a two-directional axial piston motor, an adjustable swash plate for controlling the stroke of the motor pistons, a control cylinder for positioning of said swash plate and including means to normally urge the swash plate to a relatively small displacement setting to establish a relatively high speed-low torque operation of the motor, a fluid circuit including a first valve for selectively supplying fluid to said control cylinder to move said swash plate to a second larger displacement setting to establish a relatively high torque-low speed operation of the motor, said fluid circuit including a first flow-regulating valve and a second valve in series for controlling the supply of pressure fluid to the motor, said fluid circuit including a return line from the motor and a second flow regulating valve for regulating the flow from the motor, said second flow-regulating valve permitting a greater rate of flow than the first flow-regulating valve, and a flow connection between the downstream sides of the flow regulating valves including a check valve preventing flow toward the second regulating valve, control means for said first and second valves including a control link pivotally connected thereto, and feedback mechanism responsive to motor operation for control of the position of the second valve.

Claim 12

A power drive unit for thrust reverser structure to impart movements thereto in either of two directions for either stow or deploy operation comprising, a bi-directional axial piston motor, an adjustable wobbler for controlling the stroke of the motor pistons to control motor displacement, a first valve connected to ports of the motor for controlling the direction of fluid flow to the motor, a first cylinder with a piston having differential areas responsive to fluid pressure for setting the position of said first valve, a fluid circuit including supply and return lines with said lines extended to said first valve, a first control valve in said supply line and movable between positions to open and close the supply line, a supply line branch extended to said first cylinder to act on the lesser area of the piston therein, a second supply line branch operatively connected to said first cylinder to act on the larger area of the piston therein in a deploy cycle, a second control valve in said second supply line branch and movable between positions to open and close the second supply line branch, a control cylinder for said wobbler including a piston connected to the wobbler, said control cylinder having a port at each end thereof and with said control cylinder piston having faces at opposite ends with equal area, one of said cylinder ports being connected to said second supply line branch whereby the existence of pressure fluid therein will urge said control cylinder piston in a direction to establish a minimum motor displacement, the other of said ports being connected to said first valve, and said first valve having means to either connect said other port to pressure or return to establish either an intermediate displacement position when the second supply line branch has pressure fluid or a maximum displacement position when the second supply line branch does not have pressure fluid.

Claim 13

A power drive unit for thrust reverser structure to impart movements thereto in either of two directions for either stow or deploy operation comprising, a bi-directional axial piston motor, an adjustable wobbler for controlling the stroke of the motor pistons to control motor displacement, a first valve connected to ports of the motor for controlling the direction of fluid flow to the motor, a first cylinder with a piston having differential areas responsive to fluid pressure for setting the position of said first valve, a fluid circuit including supply and return lines with said lines extended to said first valve, a first control valve in said supply line and movable between positions to open and close the supply line, a supply line branch extended to said first cylinder to act on the lesser area of the piston therein, a second supply line branch operatively connected to said first cylinder to act on the larger area of the piston therein in a deploy cycle, a second control valve in said second supply line branch and movable between positions to open and close the second supply line branch, a control cylinder for said wobbler including a piston connected to the wobbler, said control cylinder having a port at each end thereof and with said control cylinder piston having faces at opposite ends with equal area, one of said cylinder ports being connected to said second supply line branch whereby the existence of pressure fluid therein will urge said control cylinder piston in a direction to establish a minimum motor displacement, the other of said ports being connected to said first valve, and said first valve having means to either connect said other port to pressure or return to establish either an intermediate displacement position when the second supply line branch has pressure fluid or a maximum displacement position when the second supply line branch does not have pressure fluid.

Claim 14

A power drive unit for thrust reverser structure to impart movements thereto in either of two directions for either stow or deploy operation comprising, a two-directional axial piston motor, an adjustable wobbler for controlling the stroke of the motor pistons, a first valve connected to ports of the motor for controlling the direction of fluid flow to the motor, means urging the first valve to a position to cause the motor to operate in a stow operation, a first cylinder with a piston having differential areas responsive to fluid pressure for setting the position of said first valve, a fluid circuit including supply and return lines with said lines extended to said first valve, a first control valve in said supply line and movable between positions to open and close the supply line, a supply line branch extended to said first cylinder to act on the lesser area of the piston therein, a second supply line branch operatively connected to said first cylinder to act on the larger area of the piston therein, a second control valve in said second supply line branch and movable between positions to open and close the second supply line branch, a control cylinder for said wobbler including a piston connected to the wobbler, means connected to said control cylinder to control the position of the wobbler, a flow-restricting device in the return line, and means connected to said supply line and responsive to the pressure across the motor to control the pressure in said supply line.

Claim 15

A power drive unit for thrust reverser structure to impart movements thereto in either of two directions for either stow or deploy operation comprising, a two-directional axial piston motor, an adjustable wobbler for controlling the stroke of the motor pistons, a first valve connected to ports of the motor for controlling the direction of fluid flow to the motor, means urging the first valve to a position to cause the motor to operate in a stow operation, a first cylinder with a piston having differential areas responsive to fluid pressure for setting the position of said first valve, a fluid circuit including supply and return lines with said lines extended to said first valve, a first control valve in said supply line and movable between positions to open and close the supply line, a supply line branch extended to said first cylinder to act on the lesser area of the piston therein, a second supply line branch operatively connected to said first cylinder to act on the larger area of the piston therein, a second control valve in said second supply line branch and movable between positions to open and close the second supply line branch, a control cylinder for said wobbler including a piston connected to the wobbler, means connected to said control cylinder to control the position of the wobbler, a flow-restricting device in the return line, and means connected to said supply line and responsive to the pressure across the motor to control the pressure in said supply line.

Claim 16

A power drive unit for imparting two-directional drive to a mechanism with different torque demands at different times in the cycle of operation comprising, a two-direction motor with a displacement-varying means, a control cylinder having a piston connected to said displacement-varying means, a first circuit connected to said motor and including a valve for controlling the direction and volume of flow to the motor, a second circuit connected to said control cylinder and including valve means for controlling the position of the piston in the cylinder to control the position of said displacement-varying means, a control member for positioning of said valve, a hydraulically-operated power cylinder including a differential area piston for positioning of said control member to establish the direction of operation of the motor, feedback mechanism acting on said control member and responsive to operation of said motor to move said valve to a reduced flow position, means including a first valve for applying fluid pressure at all times during operation to the lesser area of the piston, and means including a second selectively operable valve for applying fluid pressure to the larger area of the piston.

Claim 17

A power drive unit for imparting two-directional drive to a mechanism with different torque demands at different times in the cycle of operation comprising, a two-direction motor with a displacement-varying means, a control cylinder having a piston connected to said displacement-varying means, a first circuit connected to said motor and including a valve for controlling the direction and volume of flow to the motor, a second circuit connected to said control cylinder and including valve means for controlling the position of the piston in the cylinder to control the position of said displacement-varying means, a control member for positioning of said valve, a hydraulically-operated power cylinder including a differential area piston for positioning of said control member to establish the direction of operation of the motor, feedback mechanism acting on said control member and responsive to operation of said motor to move said valve to a reduced flow position, means including a first valve for applying fluid pressure at all times during operation to the lesser area of the piston, and means including a second selectively operable valve for applying fluid pressure to the larger area of the piston.

Claim 18

A power drive unit for thrust reverser structure to impart two-directional drive thereto with different torque demands at different times in the stow and deploy cycles of operation comprising, a bi-directional axial piston motor with a displacement-varying wobbler, a control cylinder having a piston connected to said wobbler, a first circuit connected to said motor and including a valve for controlling the direction and volume of flow to the motor, a second circuit connected to said control cylinder and including valve means for controlling the position of the piston in the cylinder to control the position of said wobbler, a control member for positioning of said valve, feedback mechanism acting on said control member and responsive to operation of said motor to move said valve to a reduced flow position, a hydraulically-operated power cylinder for positioning of said control member to establish the direction of operation of the motor, and spring means acting on said valve to urge the valve to a position to cause motor operation in a stow cycle and through said control member act on said power cylinder to reset the latter to a stow cycle position upon removal of hydraulic power therefrom.

Claim 19

A power drive unit for thrust reverser structure to impart two-directional drive thereto with different torque demands at different times in the stow and deploy cycles of operation comprising, a bi-directional axial piston motor with a displacement-varying wobbler, a control cylinder having a piston connected to said wobbler, a first circuit connected to said motor and including a valve for controlling the direction and volume of flow to the motor, a second circuit connected to said control cylinder and including valve means for controlling the position of the piston in the cylinder to control the position of said wobbler, a control member for positioning of said valve, feedback mechanism acting on said control member and responsive to operation of said motor to move said valve to a reduced flow position, a hydraulically-operated power cylinder for positioning of said control member to establish the direction of operation of the motor, and spring means acting on said valve to urge the valve to a position to cause motor operation in a stow cycle and through said control member act on said power cylinder to reset the latter to a stow cycle position upon removal of hydraulic power therefrom.

Claim 20

A power drive unit for imparting two-directional drive to a mechanism with different torque demands at different times in the cycle of operation comprising, a two-direction motor with a displacement-varying means, a control cylinder having a piston connected to said displacement-varying means, a first circuit connected to said motor and including a valve for controlling the direction and volume of flow to the motor, a second circuit connected to said control cylinder and including valve means for controlling the position of the piston in the cylinder to control the position of said displacement-varying means, said first circuit having first valve means for limiting the rate of fluid flow to said motor and second valve means for limiting the rate of fluid flow from the motor, said second valve means permitting a larger rate of flow than said first valve means, and a flow connection from the outlet of the second valve means to the first circuit between said first valve means and said first-mentioned valve.

Claim 21

A power drive unit for imparting two-directional drive to a mechanism with different torque demands at different times in the cycle of operation comprising, a two-direction motor with a displacement-varying means, a control cylinder having a piston connected to said displacement-varying means, a first circuit connected to said motor and including a valve for controlling the direction and volume of flow to the motor, a second circuit connected to said control cylinder and including valve means for controlling the position of the piston in the cylinder to control the position of said displacement-varying means, said first circuit having first valve means for limiting the rate of fluid flow to said motor and second valve means for limiting the rate of fluid flow from the motor, said second valve means permitting a larger rate of flow than said first valve means, and a flow connection from the outlet of the second valve means to the first circuit between said first valve means and said first-mentioned valve.

Claim 22

A power drive unit for imparting two-directional drive to a thrust reverser mechanism with different torque demands at different times in the cycles of operation including low torque and high speed in a deploy cycle and high torque and low speed in a stow cycle comprising, a two-direction variable displacement hydraulic motor with a displacement-varying means, a control cylinder having a piston connected to said displacement-varying means, a first circuit connected to said motor and including a valve for controlling the direction and volume of hydraulic flow to the motor and providing the same full rate of flow to said motor at the beginning of each of said cycles, a second circuit connected to said control cylinder and including valve means operable independently of said valve for establishing the position of the piston in the cylinder at the beginning of each cycle to control the position of said displacement-varying means and have an intermediate motor displacement for starting the deploy cycle and a maximum displacement for starting the stow cycle, and means operable at a predetermined position of the thrust reverser mechanism during the deploy cycle to reduce the motor displacement.

Claim 23

A power drive unit for imparting two-directional drive to a thrust reverser mechanism with different torque demands at different times in the cycles of operation including low torque and high speed in a deploy cycle and high torque and low speed in a stow cycle comprising, a two-direction variable displacement hydraulic motor with a displacement-varying means, a control cylinder having a piston connected to said displacement-varying means, a first circuit connected to said motor and including a valve for controlling the direction and volume of hydraulic flow to the motor and providing the same full rate of flow to said motor at the beginning of each of said cycles, a second circuit connected to said control cylinder and including valve means operable independently of said valve for establishing the position of the piston in the cylinder at the beginning of each cycle to control the position of said displacement-varying means and have an intermediate motor displacement for starting the deploy cycle and a maximum displacement for starting the stow cycle, and means operable at a predetermined position of the thrust reverser mechanism during the deploy cycle to reduce the motor displacement.

Claim 24

A power drive unit as defined in claim 14 further including means operable just prior to the end of the deploy cycle for moving said displacement-varying means back to said position for intermediate motor displacement.