Built-Up Propeller With Tapered Blade Roots
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Solution Overview
Problem
Existing propeller designs face challenges such as high production costs, complex manufacturing processes, and limited repairability due to the use of cast metal components and complex geometries, particularly when using composite materials, which restricts the use of interchangeable blades and efficient force transmission.
Innovation Solution
A built-up propeller design featuring a central supporting body with tapering propeller blades and detachable wing shoes made of composite materials, where the blades are securely fastened using standardized screw connections and metallic cores for enhanced force transmission, allowing for easy replacement and improved damping properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If propeller blades are made as single-piece cast metal parts, then production is relatively simple, but repair is not possible and replacement is expensive
Solution Approach 1:
The propeller is divided into separate components: a hub and detachable blades. The blades can be individually removed and replaced without replacing the entire propeller, enabling repair while maintaining manufacturing simplicity through standardized blade designs with tapered roots that fit into the hub.
2Reliability
If dovetail-shaped grooves are provided on the hub circumference for blade attachment, then blade connection is secure, but production becomes extremely complex and expensive
Solution Approach 1:
Instead of providing complex dovetail grooves in the hub, the invention inverts the approach by providing the dovetail-shaped structure on the blade roots themselves. These tapered roots with transverse slots are inserted into simpler recesses in the hub, achieving secure form-fitting and force-locking connections while greatly simplifying hub manufacturing.
3Object-affected harmful factors
If composite material blades are used, then damping properties improve and signature decreases, but force transmission becomes problematic
Solution Approach 1:
The blades are constructed from composite materials (such as fiber-reinforced plastics) which provide superior damping properties and lower acoustic signature. The composite structure is designed with a tapered root section that includes a metallic core or reinforcement elements to ensure effective force transmission from the blade to the hub while maintaining the benefits of composite materials.
4Ease of repair
If blades are detachably attached to the hub, then individual blade replacement is possible, but connection problems arise
Solution Approach 1:
The blade is segmented into a blade proper and a tapered root section that forms an independent attachment component. This segmented design allows the blade to be detached and replaced while the root section remains with the hub, enabling easy maintenance while maintaining reliable connections through the tapered form-fitting geometry.
Solution Approach 2:
The blade root employs a tapered conical geometry that creates a form-fitting connection with the hub. This curved, tapered surface provides natural alignment and secure engagement, ensuring reliable force transmission while allowing for easy assembly and disassembly of the blade.
Data Source
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AI summary
It is a built-up propeller with a central support body (1) and at least two propeller blades (5) attached to it around the circumference. The cross-section of the propeller blades (5) tapers in their root region (11) closest to the support body with increasing radial distance from the support body (1). The shoe (10) receiving the root (11) of a blade (5) has a correspondingly inverted cross-sectional profile and engages the blade (5) in a form-fitting manner in the area of the blade root (11). The blade shoe (10) is attached to the support body (1).