Rotor Positioning Device for Impact Mill Hammer Alignment

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Solution Overview

Problem

Conventional impact mills require manual and labor-intensive adjustments of the rotor position to maintain uniform particle size, which is cumbersome and risky, especially when changing hammers on rotors with varying numbers of hammers, and lacks adaptability to different hammer configurations.

Innovation Solution

A device with a geared motor and indexing system that automatically positions the rotor to align hammers with impact screens, using a pinion and toothed wheel mechanism, along with sensors for precise positioning and end-of-travel detection, allowing for easy adaptation to different hammer counts and facilitating hammer replacement without manual rotation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If manual adjustment of rotor position is used, then the spacing between hammer and screen can be adjusted, but operator effort and risk increase significantly

Engineering Contradiction:

Improveease of rotor positioningVSAvoidoperator safety

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The system uses sensors to automatically detect the position of hammers and screens, and the control unit autonomously calculates and executes the positioning commands without requiring manual intervention. The rotor positioning device self-adjusts based on feedback from sensors, making the system self-servicing and eliminating manual rotation operations that pose safety risks to operators.

Inventive Principle:

Principle #25Self-service

2Measurement precision

If fixed indexing part with prism shape is used, then rotor can be positioned for adjustment, but adaptability to different hammer configurations is lost

Engineering Contradiction:

Improveprecision of rotor positioningVSAvoidadaptability to different hammer counts

Core Design Contradiction:

Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The system transitions from a static, fixed indexing part to a dynamic sensor-based detection system. Sensors can detect the positions of hammers and screens regardless of their arrangement or number, and the control unit dynamically calculates the optimal positioning based on real-time data. This dynamic approach allows the system to adapt to different hammer configurations while maintaining precise positioning capability.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The sensor-based positioning system serves multiple functions: it detects hammer positions, screens positions, calculates optimal spacing, and controls rotor positioning. This universal system replaces the specialized prism indexing part and can handle various hammer configurations, making the device versatile and adaptable to different milling requirements.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Ease of repair

If manual rotation of rotor is required for hammer replacement, then hammer can be changed, but operator effort and time increase

Engineering Contradiction:

Improveease of hammer replacementVSAvoidtime for hammer replacement

Core Design Contradiction:

Ease of repairVSLoss of time

Solution Approach 1:

The system replaces manual mechanical rotation of the rotor with an automated rotor positioning device driven by a motor. The control unit receives commands to rotate the rotor to specific positions where hammers can be easily accessed and replaced. This mechanical substitution eliminates the need for operators to manually rotate heavy rotors, significantly reducing effort and time required for hammer replacement operations.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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

Automates the adjustment of the rotor position and hammer alignment, reducing operator effort and risk, and enabling flexible adaptation to various hammer configurations, improving the efficiency and safety of the milling process.

Implementation Method 1

a geared motor (11) which can be moved translationally between a first position in which said pinion (12) is freed from engagement with said toothed wheel (13) and a second position in which said pinion (12) is engaged with said toothed wheel (13)

Methodology Applied

Scientific EffectElectromagnetic conversion: Electromagnetic Induction

Implementation Method 2

indexing means comprising a fixed sensor (21) arranged at one end of the shaft (3) of the rotor and able to detect the passage of locating members (22)

Methodology Applied

Scientific EffectElectromagnetic detection: Electromagnetic Induction

Data Source

PatentUS9289771B2Impact mill having a rotor-positioning device

Publication Date: 2016.03.22 METSO OUTOTEC FINLAND OY

AI summary

The mill includes a milling chamber (1) containing a rotor (2) provided with hammers (4), and at least one impact screen mounted pivotably with the aid of an adjusting jack in order to move the bottom end of the screen toward or away from the rotor so as to define, between the bottom end of the screen and the free end of the hammers, a spacing which determines a given particle size. The mill includes a device for positioning the rotor that includes indexing elements for positioning the end of one of the hammers as close as possible to the screen for adjusting the spacing. It includes a geared motor driving a pinion capable of engaging with a toothed wheel fixed in rotation to the rotor so as to rotate it from a rest state until one of the hammers is as close as possible to the screen.