Extruded Ring Gear Production for Flexible Planetary Gear Specs

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Solution Overview

Problem

The existing methods for producing ring gears for planetary gears, such as injection molding, are costly and time-consuming, especially for small series production, as they require new molds for each specification, leading to high manufacturing costs and time inefficiencies.

Innovation Solution

A method utilizing an extrusion process to produce a ring gear, where an endless profile is pressed out and cut to a predetermined length, allowing for internal gearing formation directly, with the option to adjust the number of teeth and use laser cutting to minimize post-processing and reduce production costs, using plastic materials like PBT, POM, or PEEK for cost-effectiveness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If injection molding is used to produce ring gears, then manufacturing precision and reliability are improved, but manufacturing cost and production time increase due to the need for new molds for each specification

Engineering Contradiction:
Improvering gear manufacturing precisionVSAvoidmanufacturing cost
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent applies universality by creating a single mold that can produce multiple ring gear specifications through adjustable cutting positions. Instead of requiring separate molds for each specification, the universal mold can accommodate different cutting lengths and tooth configurations, allowing one mold to serve multiple production purposes and reducing overall manufacturing cost.

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

Solution Approach 2:

The patent implements dynamics by making the cutting position adjustable during the molding process. The cutting device can be positioned at different locations along the extruded profile to create ring gears with different numbers of teeth and specifications. This dynamic adjustment capability eliminates the need for static, dedicated molds for each specification.

Inventive Principle:
Principle #15Dynamics

2Manufacturing precision

If injection molding is used to produce ring gears, then manufacturing precision is improved, but production time increases due to mold manufacturing and setup

Engineering Contradiction:
Improvering gear manufacturing precisionVSAvoidproduction time
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The universal mold design allows a single mold to produce multiple ring gear specifications by adjusting the cutting position. This eliminates the time required to manufacture and switch between multiple dedicated molds, significantly reducing production time while maintaining manufacturing precision through controlled cutting operations.

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

Solution Approach 2:

The patent applies preliminary action by pre-configuring the mold with adjustable cutting mechanisms that can be positioned for different specifications before production begins. The extrusion process continuously produces profiles that are then cut to specific lengths, allowing rapid production changes without retooling time.

Inventive Principle:
Principle #10Preliminary action

3Manufacturing precision

If new molds are manufactured for each ring gear specification, then manufacturing precision for that specification is improved, but device complexity and initial cost increase

Engineering Contradiction:
Improvespecification-specific manufacturing precisionVSAvoidmold system complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent reduces device complexity by replacing multiple specification-specific molds with a single universal mold system. The universal mold incorporates adjustable cutting mechanisms that can be repositioned to produce different ring gear specifications, simplifying the overall mold inventory and reducing the complexity of managing multiple dedicated molds.

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

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 method enables the simple and cost-effective production of ring gears with adjustable specifications, reducing manufacturing time and eliminating the need for multiple molds, allowing for quick production of various configurations from a single endless profile, and enabling a modular system with different ring gears for planetary gears.

Implementation Method 1

a continuous profile is produced by an extrusion process

Methodology Applied
Scientific EffectExtrusion: Extrusion

Implementation Method 2

the continuous profile is cut to a predetermined length

Methodology Applied
Scientific EffectLaser cutting: Laser Ablation

Data Source

PatentEP3496930B1Method for producing a ring gear for a planetary gearing and modular system having such a ring gear
Publication Date: 2021.08.25 BUHLER MOTOR GMBH
  • EP3496930B1 patent drawingFigure 1~2
  • EP3496930B1 patent drawingFigure 3~4
  • EP3496930B1 patent drawingFigure 5~6

AI summary

The problem addressed by the invention is that of producing a ring gear (10) for a planetary gearing (1), which has hitherto not been adequately solved. In particular, high costs in the event of requirement changes are disadvantageous. This problem is solved by means of a method for producing a ring gear (10) for a planetary gearing (1), wherein an endless profile (16) is produced by means of an extrusion process and the endless profile (16) is then cut to a predefined cut length (C, C1, C2, C3) in order to form a ring gear body (12, 12', 12'', 12''').