Propeller Shaft Sleeve Coating for Corrosion Resistance
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Solution Overview
Problem
The existing propeller shaft designs are prone to corrosion and rust due to exposure to rainwater, which can lead to the fixation of the shaft and constant velocity joint components, compromising their operational durability and torque transmission efficiency.
Innovation Solution
A propeller shaft design featuring a sleeve member coated with a rust-resistant material, combined with a press-fit insert portion and a seal ring to prevent water ingress and corrosion, ensuring the shaft and joint components remain functional and durable.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a seal member is used to seal the annular clearance between the shaft and sleeve member, then water ingress is prevented, but the outward region remains exposed to rain water and prone to corrosion
Solution Approach 1:
The sleeve member is divided into two distinct regions: an inward region with enhanced corrosion resistance (through coating or material selection) and an outward region with standard properties. This segmentation allows the inward region to resist corrosion from sealed areas while the outward region maintains basic functionality, resolving the contradiction between sealing performance and overall corrosion resistance.
Solution Approach 2:
The sleeve member exhibits non-uniform material properties or surface treatment, with the inward region having superior corrosion resistance compared to the outward region. This local quality enhancement targets the specific area most vulnerable to corrosion while maintaining cost-effectiveness and functional performance in other regions.
2Ease of manufacture
If the annular clearance is left open for ease of assembly, then manufacturing is simplified, but corrosion and rust can occur between the shaft and sleeve member
Solution Approach 1:
The sleeve member is pre-treated with corrosion-resistant coating or material in the inward region before assembly. This preliminary protective action ensures that even if the annular clearance remains open for ease of assembly, the critical inward region is already protected against corrosion, resolving the contradiction between manufacturing simplicity and reliability.
3Object-affected harmful factors
If rust-resistant material is used for the entire sleeve member, then corrosion resistance is improved, but manufacturing cost and complexity increase
Solution Approach 1:
Instead of using rust-resistant material throughout the entire sleeve member, the invention applies enhanced corrosion resistance only to the inward region where it is most needed. This local quality approach reduces material costs and manufacturing complexity while maintaining adequate protection in the critical area, resolving the contradiction between corrosion resistance and device complexity.
Data Source
AI summary
Apparatus, such as a propeller shaft, includes an outer circumferential portion or outer race to rotate as a unit with an internal shaft (serving as the propeller shaft), an inner circumferential member or inner race to rotate as a unit with an external shaft and a plurality of balls disposed between the outer race and inner race, for transmitting rotation therebetween. A sleeve rotating as a unit with the inner race includes an inside cavity for receiving the external shaft. The sleeve is coated with a coating formed on an inside circumferential surface.