Abstract: Systems and methods are described for shoulders that can be implemented on shafts in gear systems, such as a drive train. The shoulders, in combination with other components like bearings, or nuts, can help restrict movement of the shaft within the drive train. Use of the shoulders in various embodiments can avoid the need for grind reliefs in corners. Grind reliefs can help in prior art systems where machining or grinding is used at surfaces where raceways of bearings border shoulders that are integrated with the shaft. Grind reliefs create tight spaces where edge breaks are difficult to create. Press-fit shoulders, such as described herein, allow machining and edge break creation on the shaft prior to installation of the shoulder.

Abstract: Breathing systems and methods for a gearbox is described. Embodiments preferably create a closed system for air within the gearbox. As an operating gearbox warms the air or fluid within, or an altitude change causes air to expand or contract, increased pressure can result and air can escape through tubing to a cannister. The cannister can receive the expanding air in an impermeable cavity that is proximate to a bladder open or partially open to an exterior environment. Air can press on the bladder, expanding the cavity and shrinking the bladder until a pressure equilibrium is reached. As operation of the gearbox is lowered or powered off, or another altitude change occurs, the air can cool and/or retract into the gearbox. The bladder can then expand and press on the cavity until equalizing the pressure within the cannister.

Abstract: Breathing systems and methods for a gearbox is described. Embodiments preferably create a closed system for air within the gearbox. As an operating gearbox warms the air or fluid within, or an altitude change causes air to expand or contract, increased pressure can result and air can escape through tubing to a cannister. The cannister can receive the expanding air in an impermeable cavity that is proximate to a bladder open or partially open to an exterior environment. Air can press on the bladder, expanding the cavity and shrinking the bladder until a pressure equilibrium is reached. As operation of the gearbox is lowered or powered off, or another altitude change occurs, the air can cool and/or retract into the gearbox. The bladder can then expand and press on the cavity until equalizing the pressure within the cannister.