Crowd Motor Retract Torque Control for Industrial Shovels
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Solution Overview
Problem
Industrial machines like electric rope shovels face increased structural loading due to greater weight and larger payloads, leading to tipping moments and decreased performance, which limits their design and operational capabilities.
Innovation Solution
Implementing a control system that dynamically adjusts the retract force of the crowd motor based on sensor data from the dipper handle and hoist rope angles, allowing only necessary retract force to be applied during digging operations, thereby reducing structural loading and enabling increased payloads without increasing structural loading on the machine.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the industrial machine is made larger with greater weight and larger payloads, then the payload capacity is improved, but the structural loading and tipping moments increase
Solution Approach 1:
The patent implements dynamic control of the crowd motor retract force based on real-time sensor feedback about dipper position and loading conditions. The retract force is adjusted continuously throughout the digging cycle rather than being applied at fixed levels, allowing the system to optimize payload capacity while minimizing peak structural loading. This dynamic adjustment resolves the contradiction by enabling larger payloads without proportionally increasing structural loading through intelligent force management.
Solution Approach 2:
The system changes the retract force parameter dynamically based on operating conditions, transitioning from static to variable force application. By monitoring dipper handle angle, hoist rope angle, and other parameters, the control system adjusts the crowd motor torque to maintain optimal values that support increased payload capacity while keeping structural loading within acceptable limits.
2Speed
If maximum retract force is applied during the transition from digging to swing cycle, then the dipper is quickly repositioned, but high structural loading and tipping moments occur
Solution Approach 1:
The patent applies periodic modulation to the retract force during the digging cycle, varying the force level according to the phase of operation. During the transition from digging to swing, the system applies controlled retract force pulses that achieve necessary dipper repositioning while avoiding sustained maximum force application. This periodic action pattern enables fast repositioning without the continuous high structural loading that would result from maintaining maximum retract force.
Solution Approach 2:
The crowd motor retract force is dynamically adjusted throughout the digging and swing cycle based on real-time sensor feedback. The system transitions smoothly between different force levels rather than applying abrupt maximum force, enabling the dipper to be repositioned at appropriate speeds while minimizing peak structural loading and tipping moments during the critical transition phase.
3Productivity
If larger dipper and heavier payload are used, then the productivity is improved, but the machine structure size must be increased to handle the loading
Solution Approach 1:
The system utilizes parameter changes in the crowd motor retract force to enable larger dippers and heavier payloads without proportionally increasing machine structure size. By dynamically optimizing the retract force based on actual loading conditions and dipper position, the control system allows the existing structure to safely handle increased payload capacities that would otherwise require larger structural components, thereby improving productivity without increasing machine volume.
Data Source
AI summary
A controller that includes a memory and an electronic processor. The electronic processor receives a first signal and a second signal. The electronic processor determines a retract torque limit based on the first signal and the second signal. The electronic processor sets a retract torque parameter of a crowd motor to the retract torque limit that has been determined. The electronic processor operates the crowd motor at or below the retract torque parameter.