Nut Assembly Hot Pressing Torque Transmission
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Solution Overview
Problem
Conventional nut assemblies for fixing wheels or rims to vehicle axles are costly to manufacture due to multiple processing steps, including cold forming, turning, and hardening and tempering, and do not efficiently transmit torque.
Innovation Solution
A single hot pressing process is used to form the pressure disk in a progressive die, eliminating cold forming, turning, and separate tempering, with defined cooling to achieve microstructure and material properties comparable to hardening and tempering, and a non-standard round external profile for the nut body to enhance torque transmission and material distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If multiple manufacturing steps (cold forming, turning, hardening and tempering) are used to produce the pressure disk, then material strength and microstructure are improved, but manufacturing cost and process complexity increase
Solution Approach 1:
The patent combines multiple separate manufacturing operations (cold forming, turning, hardening, and tempering) into a single hot pressing process. The hot pressing operation simultaneously forms the pressure disk geometry and applies heat treatment to achieve the required material strength and microstructure, eliminating the need for separate processing steps and reducing overall manufacturing complexity
Solution Approach 2:
The patent changes the processing parameters from conventional cold forming followed by separate heat treatment to hot pressing with controlled cooling. By modifying the temperature parameter during forming and implementing a specific cooling rate, the process achieves both geometric formation and material property development in one operation, resolving the contradiction between strength requirements and process simplicity
2Force
If conventional hexagonal drive portion is used, then standard tool engagement is achieved, but torque transmission efficiency is limited
Solution Approach 1:
The patent replaces the conventional hexagonal drive portion with a round external profile featuring radial indentations. This curved geometry provides continuous contact surfaces during tool engagement, distributing torque more uniformly across the interface and improving transmission efficiency compared to the discrete flat surfaces of a hexagon, while maintaining compatibility with standard impact socket tools
3Strength
If more material is used in the pressure disk, then strength and torque capacity are improved, but manufacturing cost and material usage increase
Solution Approach 1:
The patent implements local quality optimization by concentrating material where it is most needed for torque transmission and structural integrity. The hot pressing process enables precise control of material distribution, creating varying density and strength characteristics in different regions of the pressure disk - higher density in load-bearing areas and optimized thickness in non-critical regions - thereby achieving high torque capacity with reduced overall material consumption
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 reduces manufacturing costs and increases transmissible torque while maintaining performance characteristics, using less material and achieving uniform contact patterns for improved tool engagement and centering.
Implementation Method 1
the forming process is a hot pressing process, which can be carried out in a progressive die
Implementation Method 2
it includes only a single heating process. It can be particularly advantageous if cooling of the pressure disk after hot forming is defined or controlled, so that the pressure disk is cooled according to a specified time/temperature profile
Data Source
AI summary
The invention relates to both nut assemblies and methods for producing the same. Said nut assemblies consist of a nut body (1a) and a pressure disk (2a). The nut body has a drive portion, such as a polygonal portion, for engaging with a tool and an abutment region that can be brought into contact with the supporting surface of the pressure disk arranged on the nut body in a captive manner. The pressure disk has a central opening into which a neck formed on the nut extends axially at least in part. The neck has a projection for forming a captive connection. This projection radially overlaps or engages the thrust ring.