Propeller assembly including a rigging free beta tube
An example apparatus includes a propeller assembly including a blade and a propeller shaft, the propeller shaft including a first gallery and a second gallery; and a beta tube rotationally fixed to the propeller shaft, the beta tube axially translating with respect to the propeller shaft, the beta tube including a first connection, the first connection to provide hydraulic fluid to a pitch chamber to adjust a pitch of the blade to a first pitch angle, the first connection fluidly coupled to the first gallery of the propeller shaft based on a position of the beta tube.
1 . An apparatus comprising:
a propeller assembly including a blade and a propeller shaft, the propeller shaft including a first gallery; and
a beta tube rotationally fixed to the propeller shaft, the beta tube axially translating with respect to the propeller shaft, the beta tube including a first connection, the first connection to provide hydraulic fluid to a pitch chamber to adjust a pitch of the blade to a first pitch angle, the first connection fluidly coupled to the first gallery of the propeller shaft based on a position of the beta tube.
2 . The apparatus of claim 1 , wherein the pitch chamber is a fine pitch chamber, the beta tube coupled to a piston, the piston to separate the fine pitch chamber from a coarse pitch chamber.
3 . The apparatus of claim 1 , wherein the pitch chamber is a fine pitch chamber, wherein providing the hydraulic fluid to the fine pitch chamber causes the beta tube to move in a first axial direction and wherein providing hydraulic fluid to a coarse pitch chamber causes the beta tube to move in a second axial direction.
4 . The apparatus of claim 1 , wherein the beta tube includes a connection to a crosshead assembly to transfer axial movement of the beta tube into pitch adjustment of the blade.
5 . The apparatus of claim 1 , wherein the propeller assembly includes a spring to cause the beta tube to adjust the pitch of the blade to a second pitch angle.
6 . The apparatus of claim 5 , wherein providing hydraulic fluid to the pitch chamber overrides an ability of the spring to cause the beta tube to adjust the pitch of the blade to the second pitch angle.
7 . The apparatus of claim 1 , wherein:
the propeller assembly includes a second gallery; and
the beta tube includes a second connection to provide hydraulic fluid to a coarse pitch chamber to adjust the pitch of the blade to a second pitch angle, the second connection fluidly coupled to the second gallery of the propeller shaft.
8 . The apparatus of claim 7 , further including a transfer sleeve including a first opening and a second opening, the first opening fluidly coupled to the first gallery and one or more control valves, the second opening fluidly coupled to the second gallery and the one or more control valves.
9 . The apparatus of claim 8 , further including a seal between the transfer sleeve and the propeller shaft.
10 . The apparatus of claim 9 , wherein the seal is a labyrinth seal.
11 . The apparatus of claim 8 , wherein the first gallery is wider than the first opening and the second gallery is wider than the second opening.
12 . The apparatus of claim 8 , wherein the PCU transfer sleeve does not rotate with rotation of the beta tube.
13 . The apparatus of claim 1 , further including a seal between the propeller shaft and the beta tube.
14 . The apparatus of claim 13 , wherein the seal is a bushing seal.
15 . An apparatus comprising:
a blade;
a propeller shaft coupled to the blade, the propeller shaft including a first gallery and a second gallery, the first and second galleries fluidly coupled to a pump via one or more control valves; and
a beta tube rotationally fixed to the propeller shaft, the beta tube axially translating with respect to the propeller shaft, the beta tube including a first connection and a second connection, the first connection to provide hydraulic fluid to a first pitch chamber to adjust a pitch of the blade to a first pitch angle, the second connection to provide hydraulic fluid to a second pitch chamber to adjust the pitch of the blade to a second pitch angle, the first connection fluidly coupled to the first gallery of the propeller shaft based on a position of the beta tube, the second connection fluidly coupled to the second gallery of the propeller shaft.
16 . The apparatus of claim 15 , wherein the first pitch chamber is a fine pitch chamber, the second pitch chamber is a coarse pitch chamber, and further including a piston to separate the fine pitch chamber from the coarse pitch chamber.
17 . The apparatus of claim 15 , wherein the beta tube is coupled to a piston, the piston to separate the first pitch chamber from the second pitch chamber.
18 . The apparatus of claim 15 , wherein providing the hydraulic fluid to the first pitch chamber causes the beta tube to move in a first axial direction and providing hydraulic fluid to the second pitch chamber causes the beta tube to move in a second axial direction.
19 . An engine comprising:
a low pressure shaft;
a propeller assembly including a blade and a propeller shaft, the propeller shaft including a first gallery and a second gallery;
a gearbox to translate a first rotation of the low pressure shaft into a second rotation of the propeller shaft, the blade to rotate with the second rotation; and
a beta tube rotationally fixed to the propeller shaft, the beta tube axially translating with respect to the propeller shaft, the beta tube including a first connection and a second connection, the first connection to provide hydraulic fluid to a first pitch chamber to adjust a pitch of the blade to a first pitch angle, the second connection to provide hydraulic fluid to a second pitch chamber to adjust the pitch of the blade to a second pitch angle, the first connection fluidly coupled to the first gallery of the propeller shaft based on a position of the beta tube, the second connection fluidly coupled to the second gallery of the propeller shaft.
20 . The engine of claim 19 , further including a transfer sleeve including a first opening and a second opening, the first opening fluidly coupled to the first gallery of the propeller shaft and one or more control valves, the second opening fluidly coupled to the second gallery of the propeller shaft and the one or more control valves.