Prop-rotor Spinner Cooling Tail Section Gearbox
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Solution Overview
Problem
Existing propeller gearboxes in rotary wing aircraft require complex and weight-added cooling systems, such as oil coolers, to manage high rotational speeds and heat dissipation.
Innovation Solution
A propeller system that utilizes a spinner assembly with a fan driven by the propeller shaft to draw airflow through cooling inlets in the aircraft's tail section, which then cools the propeller gearbox without the need for an oil cooler.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a dedicated cooling system (such as an oil cooler) is used to cool the propeller gearbox, then the cooling effectiveness is improved, but the device complexity and weight increase
Solution Approach 1:
The patent combines the cooling function with the existing spinner assembly structure. The spinner assembly, which already exists for aerodynamic purposes, is modified to include cooling features (openings, passages, or integrated cooling elements) rather than adding a separate dedicated cooling system. This merging approach provides effective cooling while avoiding the complexity and weight penalties of a standalone cooling system.
Solution Approach 2:
The spinner assembly is designed to serve multiple functions: its original aerodynamic role plus a new cooling function for the propeller gearbox. By making the spinner assembly multi-functional, the patent eliminates the need for separate dedicated cooling components, thereby reducing overall system complexity and weight while maintaining effective cooling capability.
2Temperature
If a dedicated cooling system (such as an oil cooler) is used to cool the propeller gearbox, then the cooling effectiveness is improved, but the weight increases
Solution Approach 1:
The cooling function is merged into the existing spinner assembly structure, eliminating the need for separate cooling components that would add weight. The spinner assembly serves dual purposes (aerodynamic and cooling), thereby providing effective gearbox cooling without the weight penalty of a dedicated cooling system.
Solution Approach 2:
The spinner assembly is designed as a multi-functional component that performs both its traditional aerodynamic function and a new cooling function. This universality approach allows the system to achieve effective cooling while minimizing weight increase, as the same structural element serves multiple purposes rather than requiring additional dedicated cooling components.
3Speed
If the propeller shaft rotates at high speed to drive the rotor system, then the rotor system performance is improved, but the propeller gearbox experiences excessive heat generation
Solution Approach 1:
The spinner assembly acts as an intermediary structure that facilitates heat removal from the propeller gearbox. By incorporating cooling openings or passages in the spinner assembly, it serves as a mediator that enables thermal energy transfer from the gearbox to the surrounding air, thereby managing the heat generated by high-speed rotation without requiring a separate dedicated cooling system.
Solution Approach 2:
The system uses the existing rotational motion of the propeller shaft and the resulting airflow to provide self-cooling of the gearbox. The high-speed rotation creates airflow that, when channeled through the spinner assembly's cooling features, automatically removes heat from the gearbox without requiring additional active cooling components or systems.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution eliminates the need for additional cooling components, reducing weight and complexity while effectively cooling the propeller gearbox through forced convection during operational flight.
Implementation Method 1
The spinner assembly is rotatable to draw the airflow into at least one cooling flow inlet formed in the tail section and across the propeller gearbox to cool the propeller gearbox and out the at least one outlet opening
Data Source
AI summary
A propeller system for a tail section of an aircraft includes a propeller hub located at the tail section of the aircraft, a plurality of propeller blades mounted to and extending outwardly from the propeller hub, a propeller shaft coupled to the propeller hub and operable to rotate the propeller hub about an axis of rotation, and a propeller gearbox connected to the propeller shaft. The propeller gearbox is fluidly cooled by an airflow within the tail section. A spinner assembly surrounds the propeller hub. The spinner assembly includes at least one outlet opening formed therein downstream from the propeller hub relative to the airflow. The spinner assembly is rotatable to draw the airflow into at least one cooling flow inlet formed in the tail section and across the propeller gearbox to cool the propeller gearbox and out the at least one outlet opening.