Synchronous Motor Conveyor Drive Inertia Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional continuous conveyor systems are prone to mechanical overload and damage due to significant mass inertia during disruptions, such as material backups or jamming, leading to high repair costs and downtime in the mining industry.
Innovation Solution
Employing a permanently excited multi-pole synchronous motor with a speed no more than 15 times that of the driveshaft, which delivers high torque, reducing the mass moment of inertia to less than 20% of conventional drives, and eliminating the need for elaborate step-down gears, allowing for direct drive of the tractive transport means.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a high-speed electric motor with multi-stage step-down gear is used, then the motor can operate at high speed (1500 rpm), but the mass moment of inertia of the drive system becomes very large, causing mechanical overload during disruptions
Solution Approach 1:
The patent replaces the conventional high-speed motor with a low-speed synchronous motor that directly drives the conveyor belt. This substitution eliminates the need for multi-stage gear reductions, thereby dramatically reducing the mass moment of inertia of the drive system and preventing mechanical overload during disruptions while maintaining reliable operation.
Solution Approach 2:
The patent fundamentally changes the operating parameters of the motor by using a low-speed synchronous motor (operating at the same speed as the driving roller, 5-100 rpm) instead of a high-speed motor (1500 rpm). This parameter change reduces the speed ratio from 150:1 to 1:1 or 15:1, thereby reducing the reflected moment of inertia and eliminating the need for complex gear systems.
2Speed
If a multi-stage step-down gear is installed between the motor and driving roller, then the motor speed can be reduced to match the driving roller speed, but the device complexity and mass moment of inertia increase significantly
Solution Approach 1:
The patent substitutes the multi-stage mechanical gear system with a low-speed synchronous motor that operates directly at the required driving roller speed. This eliminates complex gear mechanisms, reduces device complexity, and minimizes the mass moment of inertia while maintaining the necessary speed reduction from motor to roller.
3Reliability
If an overload clutch is installed to prevent mechanical damage, then the risk of damage during disruptions is reduced, but the device complexity and repair costs increase
Solution Approach 1:
The patent extracts and eliminates the overload clutch from the drive system by using a low-speed synchronous motor that inherently prevents mechanical overload through its low mass moment of inertia. This removal of the overload clutch simplifies the device while maintaining protection against mechanical damage, as the low-inertia system naturally responds faster to disruptions without requiring additional protective mechanisms.
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 solution significantly reduces the risk of mechanical overload, lowers energy consumption, and enhances system reliability, enabling faster reaction to disruptions and minimizing damage to the conveyor system, while eliminating the need for an overload clutch.
Implementation Method 1
a permanently excited multi-pole synchronous motor, the speed of which is no more than 15-times as fast as the operating speed of the driveshaft, is utilized instead of a high-speed electric motor with a multi-stage step-down gear
Data Source
AI summary
A continuous conveyor such as, for example, a conveyor belt for transporting heavy bulk materials or unit loads comprises an endless tractive transport mechanism that revolves between a driving roller and a return roller. The driving roller is driven by a permanently excited multi-pole synchronous motor that delivers a very high torque at a comparatively slow nominal speed. The synchronous motor can drive the driving roller directly or alternatively via a single-stage step-down gear with low reduction factor. The drive is characterized by a mass moment of inertia that is up to 10-times lower than in conventional drive systems. In this way, the risk of damaging or even tearing the belt during disruptions is substantially reduced such that the operational reliability significantly increases.