Hydropneumatic Roller Mill Rocker Arm Force Transmission

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Solution Overview

Problem

Existing roller mills with vertical mill axes face challenges in generating high forces required for efficient grinding, especially in large mills with high throughputs, and struggle to easily adjust forces for varying operating conditions.

Innovation Solution

The roller mill design incorporates a hydropneumatic spring system with a rocker arm having a tilting axis parallel to the grinding roller axis, mounted outside the mill housing, which allows for increased force generation and easy adjustment by diverting forces into the mill foundation, eliminating the need for housing reinforcement and reducing vibration issues.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If mechanical spring systems are used to press grinding rollers against the grinding track, then the structure is simple and easy to manufacture, but the forces generated are insufficient for high-throughput mills

Engineering Contradiction:
Improvegrinding forceVSAvoidstructural complexity
Core Design Contradiction:
ForceVSEase of manufacture

Solution Approach 1:

The patent applies hydropneumatic spring systems instead of mechanical spring systems to generate grinding forces. The hydropneumatic spring (18) uses fluid pressure to generate significantly higher forces compared to mechanical springs, enabling efficient grinding in high-throughput mills while maintaining structural feasibility.

Inventive Principle:
Principle #29Pneumatics and hydraulics

Solution Approach 2:

The patent replaces the mechanical spring system with a hydropneumatic system. The mechanical spring (17) is supplemented or replaced by a hydropneumatic spring (18) that uses hydraulic or pneumatic pressure to generate the required grinding forces, transitioning from purely mechanical to fluid-based force generation.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Force

If high forces are introduced into the mill housing to press grinding rollers, then efficient grinding is achieved, but housing reinforcements are required and vibration problems occur

Engineering Contradiction:
Improvegrinding forceVSAvoidhousing strength
Core Design Contradiction:
ForceVSStrength

Solution Approach 1:

The patent extracts the force transmission path from the mill housing by introducing rockers (6) that pivot on axes (8) extending beyond the housing. The grinding forces are transmitted through these external rockers directly to the foundation, bypassing the housing structure and eliminating the need for housing reinforcements.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The rocker arms serve as intermediary elements between the hydropneumatic spring system and the foundation. They transmit the grinding forces generated by the hydropneumatic springs directly to the foundation through their pivot points, acting as mediators that prevent force transmission through the housing.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Adaptability or versatility

If mechanical spring systems are used for force generation, then the system is simple, but the forces cannot be easily adjusted for different operating conditions

Engineering Contradiction:
Improveforce adjustabilityVSAvoidpressure system complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements a dynamic force adjustment system where the hydropneumatic spring pressure can be varied to change the grinding forces. The system transitions from fixed mechanical spring forces to dynamically adjustable hydraulic/pneumatic pressures, allowing adaptation to different operating conditions.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the physical parameter of force generation from mechanical spring compression to hydraulic/pneumatic pressure. This allows continuous adjustment of the grinding forces by varying the fluid pressure, providing adaptability to different operating conditions while using a relatively simple hydropneumatic system.

Inventive Principle:
Principle #35Parameter changes

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 configuration enables the realization of high grinding forces efficiently, even in high-throughput mills, allowing for adjustable cylinder forces and minimizing housing costs and vibrations, while maintaining geometric stability and optimizing force distribution.

Implementation Method 1

at least one hydropneumatic spring system (8) which is in active contact with the rocker arm (6) for setting the contact pressure of the grinding roller (4)

Methodology Applied
Scientific EffectHydraulic pressure: Hydraulic Press

Implementation Method 2

at least one hydropneumatic spring system (8) which is in active contact with the rocker arm (6) for setting the contact pressure of the grinding roller (4)

Methodology Applied
Scientific EffectPneumatic pressure: Pressure Increase

Implementation Method 3

the oscillating lever (6) is mounted at a distance from the mill housing (1) in such a way that the forces generated by the pressure system are dissipated into the mill foundation (11) directly or via pylons (9, 10)

Methodology Applied
Scientific EffectForce transmission: Mechanical Force

Data Source

PatentEP2125228B1Roller mill
Publication Date: 2012.06.20 THYSSENKRUPP POLYSIUS GMBH
  • EP2125228B1 patent drawingFigure 1a
  • EP2125228B1 patent drawingFigure 1b
  • EP2125228B1 patent drawingFigure 2a

AI summary

The invention relates to a roller mill comprising a mill housing, a milling track rotatably supported about a milling axis inside the mill housing, and at least one milling roller, which can be rotated about a milling roller axis and is in rolling engagement with the milling track. Furthermore, an oscillating arm is provided for the rotatable mounting of the milling roller, the arm having a tilt axis, which is disposed parallel to the milling roller axis and is supported outside the mill housing. In addition, the oscillating arm is in operative contact with a hydropneumatic spring system in order to adjust the contact pressure of the milling roller. The oscillating arm is supported outside the milling housing at a distance thereto such that the forces produced by the hydropneumatic spring system are transferred directly, or via pylons, into the mill foundation.