Honing Tool Dressing With Smooth Tooth Root Transitions

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Solution Overview

Problem

Conventional honing tools experience premature wear and reduced service life due to the need for repeated dressing, which introduces sharp notches at the tooth root area, compromising the load-bearing capacity and geometry of the gear teeth, leading to increased tool costs and potential surface cracks.

Innovation Solution

A method where the honing tool is dressed using a dressing tool with a defined base geometry that maintains smooth transitions from tooth flanks to top surfaces, eliminating the need for separate dressing tools and reducing wear by profiling the honing tool in a single operation, thereby maintaining optimal geometry and load-bearing capacity throughout its useful life.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If conventional dressing methods are used with cylindrical rollers, then the end faces of honing tool teeth can be dressed, but sharp notches are created at the tooth root area, reducing load-bearing capacity

Engineering Contradiction:
Improvedressing process simplicityVSAvoidtooth root load-bearing capacity
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The dressing process is segmented into two distinct phases: end face dressing using a cylindrical roller, and tooth flank dressing using a gear-shaped roller. This segmentation allows each dressing element to be optimized for its specific function, preventing the creation of sharp notches at the tooth root while maintaining manufacturing simplicity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A gear-shaped dressing roller with defined base geometry acts as an intermediary tool that dresses the tooth flanks of the honing tool without creating sharp edges at the tooth root. This intermediary element transfers the desired smooth transition geometry from the dressing roller to the honing tool teeth.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If multiple separate dressing tools are used for end faces and tooth flanks, then comprehensive dressing is achieved, but device complexity and process time increase

Engineering Contradiction:
Improvehonin tool geometry precisionVSAvoiddressing tool configuration
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The cylindrical and gear-shaped dressing rollers are merged into a single composite dressing tool assembly. Both dressing elements are mounted on the same arbor and rotate together, allowing simultaneous or sequential dressing of end faces and tooth flanks without requiring multiple separate tools or complex tool changes.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The composite dressing tool assembly performs multiple functions: the cylindrical roller dresses end faces while the gear-shaped roller dresses tooth flanks. This multi-functional tool eliminates the need for separate specialized tools, reducing device complexity while maintaining comprehensive dressing capability.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Duration of action of moving object

If the honing tool working length decreases due to wear, then the sharp notch effect from conventional dressing increases, but replacing the tool increases costs

Engineering Contradiction:
Improvehonin tool service lifeVSAvoidnotch effect on gear teeth
Core Design Contradiction:
Duration of action of moving objectVSObject-generated harmful factors

Solution Approach 1:

The gear-shaped dressing roller is used from the beginning of the honing tool's service life to create smooth transitions at the tooth root area. This preliminary action prevents the formation of sharp notches that would otherwise develop with wear, eliminating the need to replace the tool based on notch-related criteria and extending service life.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The dressing process converts what would normally be a harmful sharp-edged geometry into a beneficial smooth transition geometry. By intentionally creating a controlled radius at the tooth root during dressing, the method eliminates the harmful notch effect that typically develops with wear, allowing the tool to maintain its effectiveness throughout its entire service life.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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 extends the service life of the honing tool, reduces tool costs, and ensures optimal surface properties and load-bearing capacities by minimizing notches and maintaining a constant geometry, thus enhancing the honing process efficiency and reducing the risk of surface cracks.

Implementation Method 1

a dressing wheel is used which, during the dressing process, continuously rolls the honing tool to be dressed at an axial cross angle

Methodology Applied
Scientific EffectRolling contact:

Implementation Method 2

a sliding relative motion exists between the tooth flanks of the honing tool and the tooth flanks of the gear being machined, causing chip removal from the gear

Methodology Applied
Scientific EffectSliding motion:

Implementation Method 3

The honing tool consists, for example, of a resin or ceramic bond in which hard abrasive grains made of aluminum oxide, sintered aluminum oxide, or boron nitride are embedded

Methodology Applied
Scientific EffectAbrasion: Abrasion

Data Source

PatentEP3206822B1Method for dressing a honing tool, and method for honing a gear
Publication Date: 2021.05.12 PRAEWEMA ANTRIEBSTECHNIK GMBH
  • EP3206822B1 patent drawingFigure 1
  • EP3206822B1 patent drawingFigure 2
  • EP3206822B1 patent drawingFigure 3A

AI summary

The invention relates to a method for dressing a honing tool (20) using a dressing tool (21, 21') which rolls at a cross-axes angle (Σ) with the honing tool (20) during the dressing process. Each of the honing tool teeth (22), which mesh with the teeth (23; Z1, Z2, Z3, Z4) of the dressing tool (21'), has a head surface (24) to be dressed and tooth flanks (25, 26) likewise to be dressed. The aim of the invention is to allow a honing process to be carried out in the tooth base region of the gear which is to be finely machined as well, wherein neither the geometry nor the load-bearing capacity of the respective tooth is negatively influenced by the honing process. According to the invention, this is achieved in that both the head surfaces (24) as well as the tooth flanks (25, 26) of the honing tool (20) are machined in at least one advancement of the dressing tool (21') during the dressing process. At the same time, continuous transitions (31, 32) from the tooth flanks (25, 26) to the head surfaces (24) are formed on the honing tool (20) by means of tooth base curvatures (29', 30') provided on the teeth (23, 23') of the dressing tool (21, 21'). By using a honing tool dressed according to the invention, gears can be honed in a corresponding manner, wherein optimal surface finishes with respect to the load-bearing capacity are ensured even in the tooth base regions.