Magnetic Gear System for Torque Pulsation Reduction
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Solution Overview
Problem
Current vehicle powertrain systems face challenges in reducing torque pulsations from internal combustion engines, leading to increased noise, vibration, and harshness (NVH) issues, and require complex and costly components like dual mass flywheels to mitigate these effects, while also being limited by the mechanical gear's big-wheel/small-wheel principle.
Innovation Solution
The implementation of a magnetic gear system that uses a rotating set of poles with controllable windings to reduce torque pulsation transmission by maintaining a constant reaction torque, allowing for active cancellation and filtering of engine torque pulsations without the need for dual mass flywheels, and offering a more flexible gear ratio design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a dual mass flywheel is used to reduce torque pulsations, then NVH performance is improved, but device complexity and cost increase
Solution Approach 1:
The patent replaces the mechanical dual mass flywheel system with a magnetic gear system that uses magnetic fields to achieve torque pulsation reduction. The magnetic gear comprises an input rotor, output rotor, and stator with windings, where electromagnetic interactions provide the necessary torque modulation without mechanical complexity
Solution Approach 2:
The patent changes the operating parameters of the magnetic gear system, specifically controlling the current in the stator windings to maintain a substantially constant reaction torque. By adjusting electrical parameters (current magnitude and frequency) rather than mechanical parameters, the system achieves torque pulsation filtering
2Object-affected harmful factors
If a dual mass flywheel is used to reduce torque pulsations, then NVH performance is improved, but manufacturing cost increases
Solution Approach 1:
The patent replaces the mechanical dual mass flywheel system with a magnetic gear system that uses magnetic fields to achieve torque pulsation reduction. The magnetic gear comprises an input rotor, output rotor, and stator with windings, where electromagnetic interactions provide the necessary torque modulation without mechanical complexity
Solution Approach 2:
The patent employs standard electrical components (windings, magnets, rotors) that are relatively inexpensive and easily manufactured compared to precision mechanical flywheel assemblies. These electromagnetic components can be produced using conventional electrical manufacturing techniques
3Device complexity
If direct coupling between engine and drivetrain is used, then device complexity is reduced, but torque pulsations are transmitted more directly
Solution Approach 1:
The patent introduces a magnetic gear system as an intermediary between the engine and drivetrain. This magnetic gear includes a stator with controllable windings that acts as a mediator to filter torque pulsations while transmitting power, eliminating the need for complex mechanical intermediaries like dual mass flywheels
Solution Approach 2:
The patent changes the operating parameters of the magnetic gear system, specifically controlling the current in the stator windings to maintain a substantially constant reaction torque. By adjusting electrical parameters (current magnitude and frequency) rather than mechanical parameters, the system achieves torque pulsation filtering
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 effectively reduces torque pulsations, improves NVH specifications, simplifies the powertrain, and reduces costs by eliminating the need for dual mass flywheels, while providing a more efficient and flexible gear ratio control, enhancing vehicle refinement and performance.
Implementation Method 1
a rotating set of poles, which may be considered a 'virtual' rotor or may instead be a physical rotor for example carrying permanent magnets, is coupled with windings to rotate in response to a current in those windings or to rotate and induce a current in those windings
Implementation Method 2
The two other rotors of the gear, one of which carries magnetic poles and the other a set of pole pieces, are coupled to an input member and an output member
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
A system comprises an input member, an output member, a magnetic gear connecting the input member to the output member and control means arranged to control the flow of power from the input member to the output member. The magnetic gear comprises a first set of magnetic poles, a second set of magnetic poles, and a set of pole pieces arranged to modulate the magnetic field between the first set of magnetic poles and the second set of magnetic poles. The control means comprises means for reducing the transmission of torque pulsation and/or oscillation from the input member to the output member.