| 摘要 |
<p>A pair of axially movable abutments are spaced apart axially within a propeller hub. A plurality of adjustable propeller blades are rotatably mounted on the hub and each has an inner portion located inside the hub. Such inner portion is in the form of a pinion gear. Racks extend axially inwardly from each abutment and drivingly engage respective pinion gears on the blades. Compression spring or springs are positioned between the abutments and fluid pressure is used for applying an axially inward force on the abutments for moving both abutments axially inwardly toward each other in opposition to the force of the springs for the purpose of rotating the propeller blades in a first direction. The energy that is stored in the springs when compressed is used to rotate the propeller blades in the opposite direction when the fluid force is removed from the abutments. In two of the embodiments a driving shaft is solid, and the fluid motor for moving the abutments together is within the hub and in another embodiment the driving shaft is hollow and the fluid motor is positioned forwardly of the hub, connected to the forward end of the drive shaft. In the latter embodiment, the springs, in two sets, can be employed in the fluid motor.</p> |
