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US 11,530,027 B2Granted
Propeller control unit with bypass drain line
AssigneePratt & Whitney Canada Corp.
InventorJagoda Krzywon
Life of this patent
Estimating the term…
Abstract
A propeller control unit (PCU) has: a pitch angle actuator; a valve operable to selectively fluidly connect the pitch angle actuator with a source of oil for controlling pitch angles of blades of a propeller and with a drain line for draining oil out of the pitch angle actuator for feathering the blades; and a bypass line having an inlet hydraulically between the valve and an inlet of the drain line, the bypass line having an outlet hydraulically between the inlet of the drain line and an outlet of the drain line.
Claims16
A propeller control unit (PCU) comprising:
- a servo valve having a servo valve inlet hydraulically connected to a source of oil, a first servo valve outlet, and a second servo valve outlet;
- a servo valve output line hydraulically connected to the second servo valve outlet;
- a pitch angle actuator;
- a valve operable to selectively fluidly connect the pitch angle actuator with the source of oil via the first servo valve outlet for controlling pitch angles of blades of a propeller and with a drain line via a valve output line for draining oil out of the pitch angle actuator for feathering the blades, the valve output line extending from a valve outlet of the valve and leading to an oil return system, the servo valve output line hydraulically connected to the valve output line at a connection point, the drain line extending from the connection point and leading to the oil return system;
- and
- a bypass line having an inlet hydraulically connected to the valve output line between the valve outlet and an inlet of the drain line upstream of the connection point, the bypass line having an outlet hydraulically connected to the drain line between the inlet of the drain line and an outlet of the drain line downstream of the connection point.
3 more elements
A propeller control unit (PCU) comprising:
- a servo valve having a servo valve inlet hydraulically connected to a source of oil, a first servo valve outlet, and a second servo valve outlet;
- a servo valve output line hydraulically connected to the second servo valve outlet;
- a pitch angle actuator;
- a drain line;
- a valve fluidly connected to the pitch angle actuator, to the drain line via a valve output line, and to a source of oil via the first servo valve outlet, the valve operable in a first configuration in which oil circulates from the source of oil to the pitch angle actuator through the valve and through the servo valve and in which the pitch angle actuator is fluidly disconnected from the drain line, and a second configuration in which fluid communication between the source of oil and the pitch angle actuator via the valve is limited and in which the pitch angle actuator is fluidly connected to the drain line via the valve output line, the valve output line extending from a valve outlet of the valve and leading to an oil return system, the servo valve output line hydraulically connected to the valve output line at a connection point, the drain line extending from the connection point and leading to the oil return system;
- and
- a bypass line having an inlet connected to the valve output line upstream of the drain line, upstream of the connection point, and downstream of the valve, and an outlet connected to the drain line downstream of an inlet of the drain line and downstream of the connection point.
4 more elements
Dependencies are inferred from the claim text.