Servo-Driven Journal Loading for Pulverizer Mill
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Solution Overview
Problem
Existing journal loading systems in pulverizer mills, such as spring-only and hydraulic systems, lack the ability to automatically adjust grinding force during operation and require extensive maintenance and expertise, necessitating a more efficient and electronically controlled solution.
Innovation Solution
An electronically controlled journal loading system that uses a coiled spring assembly, motor, gearbox, controller, and user interface to adjust the spring force applied to the grinding roll, allowing for precise and automatic control of the grinding force through a motor-driven preload stud.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a spring-only journal loading system is used, then the structure is simple, but the system cannot automatically adjust grinding force during operation
Solution Approach 1:
The patent replaces the purely mechanical spring adjustment system with an electronically controlled motorized system. The motor-driven mechanism substitutes manual mechanical adjustment with automated electronic control, allowing the grinding force to be adjusted automatically during operation while maintaining structural simplicity through integrated design.
Solution Approach 2:
The patent introduces dynamic adjustability to the journal loading system by incorporating a motor that can change the spring force in real-time. This allows the system to adapt grinding force dynamically during operation based on process requirements, transforming a static mechanical system into a dynamic controllable one.
2Extent of automation
If a hydraulic journal loading system is used, then automatic adjustment of grinding force is achieved, but the system requires extensive maintenance and expertise
Solution Approach 1:
The patent employs a motor-driven mechanism that replaces complex hydraulic systems. The motor and associated mechanical components are simpler, more reliable, and easier to maintain than hydraulic systems, reducing the need for extensive maintenance and specialized expertise while retaining automatic adjustment capability.
Solution Approach 2:
The patent extracts the hydraulic system entirely and replaces it with a motor-driven mechanical system. This removes the complex hydraulic components that require extensive maintenance and expertise, keeping only the essential automatic adjustment functionality through a simpler mechanism.
3Manufacturing precision
If a hydraulic journal loading system is used, then grinding force control is precise, but the system requires a large footprint external to the mill
Solution Approach 1:
The patent integrates the journal loading mechanism directly into the mill structure, merging the force application system with the existing mill components. This eliminates the need for external hydraulic systems and associated equipment, reducing the footprint external to the mill while maintaining precise grinding force control through the integrated motor-driven mechanism.
Solution Approach 2:
The motor-driven mechanism serves multiple functions: it provides precise grinding force control, integrates within the mill structure, and eliminates the need for separate external hydraulic systems. This multi-functionality reduces the overall footprint while maintaining control precision.
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
Enables real-time adjustment of grinding force without manual intervention, reducing maintenance needs and operational complexity, while maintaining consistent grinding performance and reducing wear on components compared to hydraulic systems.
Implementation Method 1
a coiled spring assembly, motor, gearbox, controller, and user interface to adjust the spring force applied to the grinding roll
Implementation Method 2
motor-driven preload stud
Data Source
AI summary
An electronically controlled journal loading system 20 for controlling and adjusting the amplitude of the load applied to a journal assembly 19 of a pulverizing mill 10. The journal loading system 20 includes a servomotor 44, resolver 134, vertical gearbox 42, coil spring assembly 40, controller 46 and a user interface 48. The journal loading system 20 provides electronic control and adjustment of the force applied to the journal assembly 19 to thereby increase or decrease the load that a grinding roll 18 imposes on the material being pulverized. In the mode of operation of the servo journal loading system 20, a desired load set point is selected via the user/operator interface 48. The servomotor 44 rotates a preload stud (or servo screw) 50 within the coiled spring assembly 40 in the appropriate direction via the gearbox 42. As the preload stud 50 turns, a bronze nut 100 and bushing 94 move axially along the stud to compress or decompress the spring 86. Based upon the linear movement of the preload stud 50 and the precalculated spring force of the spring 86, the load applied to the journal assembly 19 is displayed on the operator interface 48. Once the journal loading level is achieved the servomotor 44 can be turned off since the spring assembly 40 maintains the selected loading to the journal assembly 19.