Direct Drive Pulper Motor Torque Control
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Solution Overview
Problem
Conventional pulpers face issues with high maintenance costs, mechanical weak points, noise, and inefficiency due to heavy and complex drive train systems with gearing and clustered motors, which are prone to friction losses and damage from plugged conditions.
Innovation Solution
A pulper system utilizing a three-phase synchronous motor directly coupled to the rotor shaft via a frequency inverter, eliminating gearing and reducing the moment of inertia, allowing for flexible speed and torque adjustments to adapt to changing operating conditions, and incorporating load sensing to prevent plugging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional drive trains with gearing and clustered motors are used, then the rotor can be driven, but the system becomes heavy, complex, and prone to mechanical failures
Solution Approach 1:
The patent removes the gear train and intermediate transmission components from the drive system, extracting only the essential motor function. The motor is directly coupled to the rotor shaft, eliminating the complex intermediary mechanisms that caused mechanical failures and maintained high reliability standards.
Solution Approach 2:
The patent replaces the mechanical gear-based transmission system with a direct electromagnetic drive system. The motor's electromagnetic field directly drives the rotor without mechanical intermediaries, substituting a complex mechanical system with a simpler electromagnetic one that reduces failures.
2Productivity
If geared power drives are used, then the rotor can be powered, but maintenance costs increase and efficiency decreases
Solution Approach 1:
The patent extracts and removes the gear train, bearings, and couplings from the drive system, eliminating the components that require maintenance. By taking out these mechanical elements, the system achieves higher productivity with lower maintenance costs.
Solution Approach 2:
The direct drive system eliminates the need for maintenance of gear trains and intermediate components. The simplified motor-rotor connection requires minimal service intervention, allowing the system to maintain high efficiency without the ongoing maintenance burden of conventional geared drives.
3Weight of moving object
If clustered motors are used, then the weight is centered on the rotor, but friction losses occur and mechanical weak points remain
Solution Approach 1:
The patent removes the intermediate transmission elements (gears, belts, couplings) that caused friction losses. By directly coupling the motor to the rotor, the system eliminates the friction interfaces that energy loss, while maintaining centered weight distribution through the direct drive configuration.
4Speed
If large pulleys with high moment of inertia are used, then the rotor can operate at various speeds, but protective couplings are needed to prevent fracture
Solution Approach 1:
The patent employs a variable frequency motor that can dynamically adjust its operating speed to match the rotor's requirements. This dynamic speed control eliminates the need for large inertial pulleys and protective couplings, as the motor can smoothly accelerate and decelerate the rotor without mechanical shock, maintaining both speed flexibility and rotor safety.
5Force
If double belt drive is used, then high rotor torque is achieved, but the footprint increases and maintenance intensity increases
Solution Approach 1:
The patent replaces the mechanical belt drive system with a direct electromagnetic drive. The motor's electromagnetic field directly generates the required torque on the rotor without mechanical intermediaries, achieving high rotor torque with a compact footprint and reduced maintenance requirements.
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 configuration maximizes torque, reduces maintenance, minimizes noise, and enhances efficiency by eliminating the need for protective couplings, results in a lightweight and compact design suitable for mobile applications, and allows instant response to operating changes.
Implementation Method 1
a three-phase synchronous motor designed as a multipole synchronous motor, comprising to advantage 12 to 64 poles running at a speed ranging from 0 to 1000 rpm
Implementation Method 2
the torque made available at the rotor of the pulper can be maximized over the full speed range
Data Source
AI summary
The invention relates to a pulper and to its method for recycling wastes and/or product residuals. The pulper comprises a tank is which a rotor is provided for defibrating the stock mixture to be recycled, as well as a screen for drawing off the defibrated outfeed from the tank, the rotor being powered by an electric motor comprising a drive shaft in active transmission with the rotor. In accordance with the invention the electric motor is configured as a three-phase synchronous motor for operation in a speed range from 0 to 1000 rpm. It is connected to the output of a frequency inverter controlled by a controller, the output of the drive shaft being directly connected to the rotor.