Plasma Coating Screw Element Friction Control
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Solution Overview
Problem
Existing methods for coating screw elements, particularly those used in motor vehicle pipelines, face issues with variability in friction coefficients due to wet-chemical and electroplating processes, leading to inconsistent coatings and the need for costly testing to ensure compliance with standards.
Innovation Solution
A method utilizing plasma coating to apply two distinct coatings with different friction coefficients to the thread and unthreaded contact surfaces of screw elements, ensuring reproducibility and homogeneity, with the first coating covering at least 80% of the thread surface and the second coating covering at least 80% of the unthreaded contact surface, thereby setting consistent friction coefficients across the screw element.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If wet-chemical or electroplating processes are used to apply coatings to screw elements, then coatings can be applied to threads and contact surfaces, but the coefficients of friction vary greatly from screw element to screw element and the coating cannot be applied homogeneously
Solution Approach 1:
The patent replaces wet-chemical and electroplating processes with a dry mechanical coating process. A coating material in powder or granular form is applied mechanically to the screw element surfaces, eliminating the fluid-based chemical processes that caused non-uniform coating and friction coefficient variation. This mechanical application method ensures consistent coating thickness and homogeneous friction properties across all screw elements.
Solution Approach 2:
The patent changes the physical state of the coating material from liquid (in wet-chemical processes) to solid powder or granules. This parameter change enables more controlled and uniform application, as the dry material can be distributed evenly across surfaces without the variability inherent in liquid-based processes. The solid coating material maintains consistent friction coefficients across different screw elements.
2Adaptability or versatility
If different coatings with different coefficients of friction are applied to threads and unthreaded contact surfaces using wet-chemical or electroplating processes, then friction properties can be differentiated, but time-consuming and costly tests are required to verify compliance with standards
Solution Approach 1:
The mechanical coating process provides immediate visual and tactile confirmation of coating application, eliminating the need for extensive friction testing. The dry application method ensures consistent coating properties that can be verified through simple inspection rather than time-consuming mechanical tests, significantly reducing verification time while maintaining differentiated friction properties between threaded and unthreaded surfaces.
3Ease of manufacture
If wet-chemical or electroplating processes are used to apply coatings, then coatings can be applied to screw element surfaces, but the coating often cannot be applied sufficiently homogeneously over the coated surface with different coefficients of friction observed
Solution Approach 1:
The patent replaces complex wet-chemical and electroplating manufacturing processes with a simpler dry mechanical coating process. The mechanical application of powder or granular coating material is easier to control and implement, providing sufficient coating uniformity without the complexity and variability of chemical processes. This maintains ease of manufacture while significantly improving coating uniformity.
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 approach eliminates the need for time-consuming and costly testing by ensuring consistent friction coefficients across screw elements, allowing for cost-effective and simple production of screw elements with defined friction properties, reducing the risk of unintended loosening and torsional issues during screwing.
Implementation Method 1
both the first coating of the thread and the second coating of the unthreaded contact surface or contact surfaces by plasma coating on the thread or on the unthreaded contact surface(s)) is applied
Data Source
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AI summary
A method for coating a screw element, in particular a screw element for connecting pipelines 2, preferably automotive pipelines, wherein the screw element has at least one thread 3 and at least one threadless contact surface 4, 5. The thread 3 is provided at least partially with a first coating 7 and the threadless contact surface 4, 5 is provided at least partially with a second coating 8. Both the first coating 7 of the thread and the second coating 8 of the threadless contact surface 4, 5 are applied to the thread 3 and the threadless contact surface 4, 5, respectively, by plasma coating.