Vertical Mill Drive Pinion Alignment via Movable Secondary Housing

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Solution Overview

Problem

Existing drive devices for vertical roller mills face challenges in precisely adjusting the position of drive pinions relative to the output ring gear without requiring tedious adjustments, due to the size and weight of the elements, leading to mechanical stress issues.

Innovation Solution

A drive device with a secondary casing fixed to the main casing, allowing for misalignment between the drive pinion and output shaft axes, utilizing a coupling device with degrees of freedom for radial and angular misalignment, and featuring a disengagement system to manage torsion torque, enabling efficient alignment and operation with reduced mechanical stress.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the drive pinion position is precisely adjusted relative to the output ring gear to minimize mechanical stress, then the manufacturing precision and reliability improve, but the device complexity and adjustment difficulty increase due to the size and weight of components

Engineering Contradiction:
Improvedrive pinion positioning precisionVSAvoidadjustment mechanism complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The invention introduces a movable secondary housing that can shift position along the main housing, allowing the drive pinion to be dynamically repositioned. This dynamic adjustment mechanism enables precise positioning of the drive pinion relative to the output ring gear without requiring complex fixed adjustment structures, thereby resolving the contradiction between positioning precision and device complexity

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The housing is divided into two separate parts: a main housing and a movable secondary housing. This segmentation allows independent adjustment of the secondary housing position, enabling precise control of drive pinion location while simplifying the overall adjustment mechanism. The segmented design avoids the need for complex integrated adjustment systems

Inventive Principle:
Principle #1Segmentation

2Reliability

If the drive pinion position is precisely adjusted, then the mechanical stress on gear teeth is minimized, but the time required for alignment and maintenance increases

Engineering Contradiction:
Improvegear mesh reliabilityVSAvoidalignment time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The movable secondary housing enables quick repositioning of the drive pinion by simply moving the entire secondary housing along the main housing. This dynamic adjustment mechanism significantly reduces alignment time compared to traditional methods that require disassembly and reassembly of complex adjustment mechanisms, while still achieving precise positioning for optimal gear mesh

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The secondary housing is pre-configured with mounting structures and positioning features that allow for rapid installation and adjustment. This preliminary preparation of the adjustment mechanism enables quick alignment operations during installation and maintenance, reducing the time loss associated with precise positioning

Inventive Principle:
Principle #10Preliminary action

3Ease of manufacture

If the coupling device allows for misalignment between axes, then the ease of assembly improves, but the manufacturing precision of axis alignment decreases

Engineering Contradiction:
Improveassembly easeVSAvoidaxis alignment precision
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The coupling device acts as an intermediary element between the drive unit output shaft and the drive pinion. It absorbs and compensates for misalignments in the third and second axes, allowing the drive unit to be assembled with greater ease while maintaining precise effective alignment at the gear mesh interface. The coupling device mediates between the relaxed assembly tolerances and the required operational precision

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3256258B1Vertical mill drive
Publication Date: 2022.06.22 COMPAGNIE ENGRENA& REDUCTEURS MESSIAN DURAND
  • EP3256258B1 patent drawingFigure 1~2
  • EP3256258B1 patent drawingFigure 3

AI summary

The present invention relates to a drive device (10) for a vertical roller mill, said device comprising: an output ring gear (18) which is rotatable relative to a casing (12); a drive pinion (20) capable of meshing with the output ring gear; and a drive unit (26) capable of rotating the drive pinion. The drive pinion is rotatable relative to a secondary casing (22, 122), said secondary casing being rigidly connected to the main casing, such that the rotational axes (24, 14) of the pinion and of the wheel are positioned in such a way as to be fixed relative to one another. The drive shaft is connected to an output shaft (36) of the drive unit by a coupling device (42) which makes it possible for the axes (24, 40) of the pinion and of the output shaft to be misaligned.