Nickel Graphite Bushing Wear Resistance in Turbomachine Compressor Vanes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Variable pitch angle blades in turbomachines experience premature wear due to strong mechanical stresses, leading to frequent replacements and high costs, as existing graphite-based bushings fail to provide adequate friction and wear resistance.
Innovation Solution
A nickel graphite/titanium rotary contact is implemented between the sleeve and guide pivot, utilizing graphite as a solid lubricant and titanium carbide formation for enhanced wear resistance and low friction, with various production methods such as sintering or thermal spraying of nickel graphite deposits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If graphite-based bushings are used for the guide pivot, then the coefficient of friction is reduced, but wear resistance deteriorates leading to premature blade failure
Solution Approach 1:
The invention uses a composite material consisting of a nickel substrate reinforced with graphite particles and tungsten carbide coating. The nickel-graphite composite provides low friction coefficient while the tungsten carbide layer adds exceptional wear resistance, resolving the contradiction between reducing friction and improving wear resistance.
Solution Approach 2:
The invention changes the material parameters by transitioning from pure graphite to a nickel-graphite composite with controlled graphite content (10-30% by weight), and further enhances properties through tungsten carbide coating. This parameter optimization allows simultaneous achievement of low friction and high wear resistance.
2Strength
If steel guide pivots are used, then structural strength is maintained, but wear resistance deteriorates under strong mechanical stresses
Solution Approach 1:
The invention replaces steel guide pivots with a nickel-graphite composite material that maintains structural strength through the nickel matrix while achieving superior wear resistance through the graphite lubrication and tungsten carbide reinforcement, allowing operation under strong mechanical stresses without premature wear.
Solution Approach 2:
The invention changes the material composition from steel to nickel-graphite-tungsten carbide composite, optimizing the graphite content (10-30% by weight) to balance structural strength and wear resistance, enabling the guide pivot to withstand strong mechanical stresses with extended service life.
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
The solution significantly increases the lifespan of blades by reducing wear and maintaining low friction, as demonstrated by comparative tests showing reduced wear rates compared to other material couples.
Implementation Method 1
graphite acts as a solid lubricant during continuous friction, thus ensuring a relatively low coefficient of friction
Implementation Method 2
the friction of graphite on titanium results in the formation of titanium carbide on the peaks of roughness ensuring great resistance to wear between the sleeve and the blade guide pivot
Data Source
Figure 1~2
AI summary
The invention relates to a variable pitch angle blade for a turbomachine compressor, comprising a bushing (18) rotatably mounted around a guide pivot (8) of the blade intended to be mounted on a housing (22) of the turbomachine, the rotary contact between the bushing (18) and the guide pivot (8) being of the nickel graphite / titanium type.