Cold Rolling Mill Work Roll Drive Decoupling
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Solution Overview
Problem
Existing roll stands face challenges in maintaining quality and stability during skin-passing operations due to torque imbalances, chattering, and surface defects, particularly when both work rolls are driven, which is not suitable for non-ferrous metals requiring lower rolling forces.
Innovation Solution
Decoupling the upper or lower work roll from its drive device during skin-passing operations and using a torque transmission device with a clutch system to ensure only one work roll is driven, while the upper backup roll is lifted off the work roll to adjust rolling forces via bending cylinders, and implementing a pre-filtering system for lubricants to remove tinsel particles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If both work rolls are driven during skin-passing operation, then rolling torque can be applied to both rolls, but torque imbalances and chattering occur leading to surface defects
Solution Approach 1:
The patent extracts the drive function from one of the two work rolls during skin-passing operation. By decoupling the drive device from one work roll while maintaining drive to the other, the system eliminates torque imbalance between rolls. This selective extraction of the driving function resolves the chattering and surface defects caused by simultaneous dual-roll driving, while still providing sufficient rolling torque through the single driven roll.
2Adaptability or versatility
If high rolling forces are applied during reducing operation, then thickness reduction is achieved, but the same stand cannot effectively perform skin-passing with low rolling forces
Solution Approach 1:
The patent implements dynamic adaptability by enabling the roll stand to switch between two distinct operational configurations. During reducing operation, both work rolls are driven with high rolling forces for significant thickness reduction. During skin-passing operation, the system dynamically reconfigures by decoupling one work roll from the drive device and applying only low rolling forces, allowing the same stand to effectively perform both reducing and skin-passing functions without mechanical modification.
3Force
If lubricant is used during skin-passing to reduce friction, then rolling resistance decreases, but tinsel particles contaminate the lubricant and affect further processing
Solution Approach 1:
The patent converts the harmful effect of tinsel particle generation during skin-passing into a manageable issue by implementing a pre-filtering system. The pre-filter removes tinsel particles from the lubricant before it is recirculated or reused, transforming the contamination problem into a simple filtration task. This allows continuous lubricant usage with minimal contamination impact, maintaining low rolling resistance while eliminating the harmful effects of tinsel particles on further processing.
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 improves the quality of the rolled stock and stabilizes rolling conditions by reducing torque imbalances and surface defects, allowing for efficient skin-passing of both ferrous and non-ferrous metals with minimal lubricant usage, enhancing the overall operational efficiency and reducing maintenance needs.
Implementation Method 1
implementing a pre-filtering system for lubricants to remove tinsel particles
Implementation Method 2
upper backup roll is lifted off the work roll to adjust rolling forces via bending cylinders
Implementation Method 3
torque transmission device with a clutch system to ensure only one work roll is driven
Data Source
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AI summary
The invention relates to a method and a rolling stand (100) for cold rolling rolled stock. The rolling stand (100) comprises at least one upper and one lower backup roll (110-1, 110-2) and also an upper and a lower work roll (120-1, 120-2), which define a roll gap (128). Optionally, a lower and an upper intermediate roll (130-1, 130-2) may also be provided between the work rolls and the backup rolls. In order to ensure an absolutely equal circumferential speed of the upper and lower work rolls when cold rolling in skin-pass mode, it is proposed according to the invention to decouple the upper or lower work roll from its associated drive device.