Ball Screw Nut Raceway Rolling After Preliminary Thread Machining
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for producing ball raceways on workpieces, such as ball screw nuts, face challenges in achieving precise and cost-effective final thread profiles with high surface quality and resistance to mechanical stress.
Innovation Solution
A method involving the formation of a preliminary thread profile through machining, followed by thread rolling using a tool with a rolled profile that smooths and deforms the surface to create a final thread profile with improved geometry and surface finish, allowing for efficient post-processing and increased resistance through controlled plastic deformation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a preliminary thread profile is formed by machining process, then larger tolerances can be maintained making it cost-effective, but the surface quality and precision of the ball raceway is insufficient
Solution Approach 1:
A preliminary thread profile with first raceway geometry is formed on the workpiece by means of a machining process, providing a preliminary ball raceway quality with larger tolerances. This preliminary structure is then used as a base for subsequent thread rolling to achieve final precision and surface quality.
Solution Approach 2:
The method transitions from a preliminary thread profile with first raceway geometry to a final thread profile with second raceway geometry through thread rolling. The rolling profile geometry that runs annularly around the longitudinal axis transforms the preliminary structure into the final high-precision ball raceway, changing the geometric parameters and surface quality.
2Reliability
If thread rolling is used to create final thread profile, then high surface quality and resistance to mechanical stress are achieved, but the process complexity and tooling requirements increase
Solution Approach 1:
The manufacturing process is divided into two distinct stages: first, forming a preliminary thread profile by machining process; second, creating the final thread profile by thread rolling. This segmentation allows each stage to be optimized independently, with the machining stage providing cost-effective preliminary quality and the rolling stage providing high-precision final quality with improved reliability.
Solution Approach 2:
The preliminary thread profile acts as an intermediary structure between the initial workpiece and the final high-precision ball raceway. This intermediate preliminary structure with first raceway geometry enables the subsequent thread rolling process to achieve the final second raceway geometry more effectively, reducing the complexity of direct high-precision machining.
3Manufacturing precision
If the rolled profile rolls along the preliminary thread profile, then plastic deformation smooths out roughness peaks improving surface finish, but the process time and number of operations increase
Solution Approach 1:
The thread rolling tool with rolled profile geometry continuously rolls along the preliminary thread profile in one operation, creating the final thread profile through continuous plastic deformation. This continuous action smoothly deforms the surface to eliminate roughness peaks and create the final high-quality ball raceway surface finish without requiring multiple separate operations.
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 enables the production of ball raceways with enhanced surface quality, reduced roughness, and increased resistance to mechanical stress, while maintaining cost-effectiveness by leveraging existing machining processes and minimizing additional shaping requirements.
Implementation Method 1
The rolling or rolling of the rolled profile along the preliminary thread profile results in plastic deformation on the surface of the preliminary thread profile, with roughness peaks on the surface of the preliminary thread profile being smoothed out.
Data Source
Figure 1~3
Figure 4a~5c
AI summary
The invention relates to a method for producing a ball race (4) on a workpiece (2), wherein a preliminary thread profile (5a) having a first race geometry (6a) is formed on the workpiece (2) by means of a machining method, wherein the preliminary thread profile (5a) is provided for secondary machining and forming of a final thread profile (5b), wherein the workpiece (2), after machining, is clamped in a thread rolling tool having a tool shank (7), wherein a tool head (8) having a roller profile (9) is formed on a free end of the tool shank (7), wherein the workpiece (2) is rotated about a rotational axis (A) and the tool shank (7) is moved longitudinally along the workpiece (2), wherein the roller profile (9) of the tool head (8) rolls on the preliminary thread profile (5a) by means of a second race geometry (6b) to produce the final thread profile (5b) on the workpiece (2). The invention also relates to a ball screw nut (1) having a ball race (4) thus produced.