Rotor Grinding with Continuous Clamping Across Profile and Shaft Machining

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Solution Overview

Problem

Current methods for manufacturing rotors for compressors, blowers, and vacuum pumps require multiple grinding operations across different machines, leading to inefficiencies, increased costs, and quality issues due to clamping errors, heat accumulation, and the need for manual deburring, which complicates the process and increases the risk of damage.

Innovation Solution

A method that performs both cylindrical and profile grinding operations in a single grinding machine, using a universal spindle for interchangeable grinding disks and flushports, allowing for continuous clamping and reducing the need for manual deburring, thereby improving accuracy and reducing production time and costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If multiple grinding operations are performed on different machines, then various surfaces of the rotor can be manufactured, but clamping errors accumulate and manufacturing precision deteriorates

Engineering Contradiction:
Improveclamping errorVSAvoidnumber of machines
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent combines cylindrical grinding and profile grinding operations into a single universal grinding machine. The machine is equipped with both a cylindrical grinding disk and a profile grinding disk that can be interchangeably mounted on the same spindle, allowing both operations to be performed on the same workpiece without removal and re-clamping, thereby eliminating cumulative clamping errors.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The grinding machine is designed with universal functionality to perform both cylindrical grinding and profile grinding operations. The spindle can accommodate different types of grinding disks (cylindrical and profile), and the machine structure allows for interchangeable tooling, enabling one machine to replace multiple specialized machines while maintaining precision.

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

2Productivity

If the workpiece is unclamped between operations on different machines, then different grinding operations can be performed, but production time increases and the risk of damage increases

Engineering Contradiction:
Improveproduction timeVSAvoidrisk of damage
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent enables continuous grinding operations by keeping the workpiece clamped in the machine throughout the entire manufacturing process. The workpiece remains secured while the grinding disk is exchanged from cylindrical to profile type, eliminating interruptions and reducing the risk of damage associated with repeated clamping and unclamping operations.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The workpiece is initially clamped in the universal grinding machine before any grinding operations begin. This preliminary clamping is maintained throughout all subsequent operations, including the exchange of grinding disks, ensuring the workpiece remains secure and positioned accurately throughout the entire manufacturing process without repeated handling.

Inventive Principle:
Principle #10Preliminary action

3Shape

If coarse profile grinding is performed first, then the rotor body shape is formed, but heat accumulation occurs and burrs are generated

Engineering Contradiction:
Improverotor body profileVSAvoidheat accumulation
Core Design Contradiction:
ShapeVSTemperature

Solution Approach 1:

The patent employs periodic alternation between coarse profile grinding and cylindrical grinding operations. After coarse profile grinding removes significant material and forms the basic rotor body shape, the process periodically switches to cylindrical grinding to remove heat-affected zones and burrs, then returns to profile grinding for finishing, creating a rhythmic cycle that manages heat accumulation effectively.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent discards the heat-affected and burr-covered surfaces generated by coarse profile grinding by removing them through subsequent cylindrical grinding operations. This selective removal of damaged surface layers recovers the underlying healthy material, allowing the process to continue with fine profile grinding on clean, undamaged surfaces.

Inventive Principle:
Principle #34Discarding and recovering

4Ease of manufacture

If manual deburring is performed after grinding operations, then burrs can be removed, but the process becomes more complex and the risk of damage increases

Engineering Contradiction:
Improveprocess complexityVSAvoidrisk of damage
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent employs automated deburring mechanisms that are integrated into the grinding machine itself. The machine automatically removes burrs through controlled grinding or mechanical means without requiring manual intervention, allowing the workpiece to service its own deburring needs and eliminating the separate manual deburring step entirely.

Inventive Principle:
Principle #25Self-service

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 enhances the quality and efficiency of rotor manufacturing by minimizing clamping errors, reducing production time, and optimizing machine capacity, while also reducing the risk of damage and the need for manual deburring, leading to a more streamlined and cost-effective process.

Implementation Method 1

a cylindrical grinding disk (18) or a profile grinding disk (23) is taken off the universal grinding spindle (33)

Methodology Applied
Scientific EffectAbrasion: Abrasion

Data Source

PatentEP2668003B1Method for the manufacturing of a rotor
Publication Date: 2024.06.05 ATLAS COPCO AIRPOWER NV
  • EP2668003B1 patent drawingFigure 1~2
  • EP2668003B1 patent drawingFigure 3~4
  • EP2668003B1 patent drawingFigure 5~6

AI summary

Method for manufacturing a rotor (1) that at least comprises the following operations: the clamping of a workpiece (25) in a grinding machine (27); the performance of one or more cylindrical grinding operations whereby a rotor shaft section (10-14) is ground to the desired diameter with a cylindrical grinding disk (18); the performance of one more profile grinding operations whereby a rotor body (3) is profiled with a profile grinding disk (23). and whereby, during the manufacture of the rotor (1) in the grinding machine (27), the workpiece (25) is not undamped and the cylindrical grinding operations and the profile grinding operations are done with the same grinding machine (27).