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AssigneeSundstrand Corporation
InventorsRichard E. Walsh, Craig S. Legault
Estimating the term…
Drag produced by cold, viscous oil, interacting with the gear meshes of a gear drive (8) connected to a ram air turbine (2) of an aircraft (1), is controlled to allow proper start-up of the ram air turbine. The lubricating oil is isolated from the gear meshes in remote sumps (11, 12) when the turbine is located in the stowed, inoperative position. An oil metering orifice controls the oil flow from the remote sumps to gearbox sumps with movement of the turbine from the stowed position (A) to the deployed position (B), so as to delay the application of cold, viscous coil to the gear meshes until after start-up of the turbine. This avoids excessive start times and failure to start from the high drag caused by cold, viscous oil on the gear meshes.
A method of deploying a ram air turbine of an aircraft, the turbine being movable relative to the aircraft between a stowed position where the turbine is inoperative and a deployed position where the turbine is operated, a gear drive being operatively connected to the turbine and including at least one gear mesh, said method comprising storing lubricating oil for the at least one gear mesh away from the at least one gear mesh when the turbine is located in the stowed position, and when the turbine is moved from the stowed position to the deployed position applying the stored lubricating oil to the at least one gear mesh so as not to excessively delay or prevent start-up of the turbine.
A method of deploying a ram air turbine on an aircraft with a gear drive operatively connected to the turbine and having at least one gear mesh, the ram air turbine being movable relative to the aircraft between a stowed position where the turbine is inoperative and a deployed position where the turbine is operated, the method comprising moving the ram air turbine from the stowed position to the deployed position for operating the turbine and controlling the drag load on the at least one gear mesh of the gear drive from a lubricating oil for the at least one gear mesh at least when the lubricating oil is cold and viscous so as not to excessively delay or prevent start-up of the ram air turbine, wherein the step of controlling the drag load includes delaying application of the lubricating oil to the at least one gear mesh, at least when the lubricating oil is cold and viscous, until after the ram air turbine has been started.
An apparatus for lubricating a gear mesh of a gear drive operatively connected to a ram air turbine of an aircraft, said ram air turbine being movable relative to the aircraft between a stowed position where the turbine is inoperative and a deployed position where the turbine is operated, comprising a remote sump for storing lubricating oil for the gear mesh when the ram air turbine is moved to the stowed position, the sump being located away from the gear mesh, a gearbox sump in which the gear mesh is located, a lubricating oil passage extending between the remote sump and the gearbox sump for conveying lubricating oil back and forth between the respective sumps, the lubricating oil passage including an oil metering orifice which delays the flow of lubricating oil through the passage when the oil is cold and viscous.
An apparatus for lubricating a gear mesh of a gear drive operatively connected to a ram air turbine on an aircraft, the ram air turbine being movable relative to the aircraft between a stowed position where the turbine is inoperative and a deployed position where the turbine is operated, comprising a remote sump for storing lubricating oil for the gear mesh, the remote sump isolating oil from the gear mesh when the ram air turbine is in the stowed position, and means for controllably delivering lubricating oil from the remote sump to the gear mesh when the ram air turbine is moved from the stowed position to the deployed position so that when the lubricating oil is cold and viscous it does not reach the gear mesh until the ram air turbine has started operation.
Dependencies are inferred from the claim text.