Diagonal Rolling of Toothed Workpieces With Variable Surface Geometry

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Solution Overview

Problem

Current methods for producing toothed workpieces with modified surface geometry lack flexibility in specifying desired modifications, limiting the range of possible surface geometry configurations.

Innovation Solution

A diagonal rolling process using a tool with modified surface geometry, described by linear or quadratic functions, and varying pitch or crowning, allows for precise control of the workpiece's surface geometry through superimposition of tool modifications and machining kinematics changes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional dressing methods are used to produce toothed workpieces, then the manufacturing process is simple, but the flexibility in specifying desired surface geometry modifications is limited

Engineering Contradiction:
Improveflexibility in specifying surface geometry modificationsVSAvoidcomplexity of tool modification and machining process
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements dynamic control of the dressing process by continuously varying the position of the dresser relative to the tool during machining. The dresser position is adjusted as a function of the workpiece width position, enabling continuous modification of the tool's surface geometry. This dynamic adjustment mechanism allows the system to produce complex surface geometry modifications that would be impossible with static dressing methods, directly resolving the contradiction between flexibility and complexity.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the geometric parameters of the tool surface during the dressing process by controlling the dresser position as a function of workpiece width. This parameter change approach enables the production of tools with modified surface geometries including variable pitch, crowning, and other complex profiles. The ability to continuously vary these parameters during machining provides the flexibility needed to specify diverse surface geometry modifications while managing the inherent complexity through systematic control.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If the dresser position is continuously changed during dressing to achieve desired modifications, then the surface geometry precision is improved, but the manufacturing complexity increases

Engineering Contradiction:
Improveprecision of surface geometry modificationVSAvoidease of tool dressing process
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent implements a feedback-controlled dressing process where the dresser position is continuously adjusted based on the desired surface geometry modification profile. The system monitors the workpiece width position and dynamically adjusts the dresser position to achieve the target modification. This feedback mechanism ensures high precision in producing the desired surface geometry while automating the complex coordination required, thereby improving precision without proportionally increasing manufacturing difficulty.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent introduces a control system as an intermediary that coordinates the complex relationship between the dresser position, tool rotation, and workpiece width position. This intermediary control layer simplifies the manufacturing process by automatically calculating and executing the precise dresser movements needed to achieve the desired surface geometry modification, reducing the manual complexity while maintaining high precision.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Adaptability or versatility

If a tool with modified surface geometry is used in diagonal rolling process, then the workpiece surface geometry flexibility is enhanced, but the device complexity increases

Engineering Contradiction:
Improverange of surface geometry configurationsVSAvoidcomplexity of tool and machining system
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by pre-modifying the tool's surface geometry through a controlled dressing process before the actual machining operation. The tool is dressed with the desired modification profile (variable pitch, crowning, etc.) in advance, and then this pre-modified tool is used in the diagonal rolling process to produce workpieces with corresponding surface geometries. This preliminary preparation separates the complex tool modification step from the machining operation, enhancing workpiece geometry flexibility while managing system complexity through staged processing.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent extends the modification capability by introducing additional geometric dimensions to the tool surface beyond simple profile modifications. By varying the dresser position as a function of workpiece width, the system creates modifications in multiple dimensions including pitch variation, crowning, and cross-sectional geometry changes. This multi-dimensional approach to tool modification enables comprehensive control over workpiece surface geometry while using a single versatile dressing mechanism.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Data Source

PatentEP3139230B1Method for producing a toothed workpiece with modified surface geometry
Publication Date: 2025.01.01 LIEBHER VERZAHNTECHNIK GMBH
  • EP3139230B1 patent drawingFigure 1
  • EP3139230B1 patent drawingFigure 2
  • EP3139230B1 patent drawingFigure 3

AI summary

The present invention relates to a method for producing a toothed workpiece with a modified surface geometry by a diagonal rolling process using a modified tool, wherein a tool is used whose surface geometry comprises a modification which can be described at least approximately in the rolling pattern, at least locally in a first direction of the tool, by a linear and/or quadratic function, wherein the coefficients of this linear and/or quadratic function in a second direction of the tool, which is perpendicular to the first direction, are formed by coefficient functions FFtC,1, FFtL,1 and/or FFtQ,1, and/or a modification whose slope and/or crowning varies depending on the tool rotation angle and/or the tool width position.and wherein the targeted modification of the tool by the diagonal rolling process produces a corresponding modification on the surface of the workpiece, wherein the modification of the workpiece produced by the targeted modification of the tool is superimposed with a profile modification and/or a modification caused by a change in the machine kinematics during the machining process of the workpiece.