Electromagnetic Filtering Pulley for Crankshaft Decoupling
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Solution Overview
Problem
Existing filtering pulleys for internal combustion engines are complex, costly, and lack precise control for decoupling the crankshaft from the transmission system, especially in hybrid systems where energy efficiency is compromised due to torsional vibrations and passive loads.
Innovation Solution
A filtering pulley with a hub connected to the crankshaft, an annular crown, and arched elastic groups, along with an actuator system using electromagnetic means for selective coupling and decoupling, allowing torque transmission only within specific angular ranges, enabling efficient energy management in hybrid systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a filtering pulley with elastic elements is used to filter torsional oscillations, then vibration filtering is improved, but device complexity increases
Solution Approach 1:
The pulley is divided into two independently rotatable components: a hub connected to the drive shaft and a crown cooperating with the transmission belt. These segments are connected through elastic elements that allow relative rotation, enabling vibration filtering while maintaining structural simplicity in each component.
Solution Approach 2:
Elastic elements with specific stiffness parameters are introduced between the hub and crown to filter torsional oscillations. The elastic properties are carefully selected to attenuate vibrations while allowing efficient torque transmission during normal operation, resolving the contradiction between vibration filtering and structural simplicity.
2Adaptability or versatility
If disc clutches are used for decoupling the pulley from the crankshaft, then decoupling capability is improved, but manufacturing precision and control precision deteriorate
Solution Approach 1:
The connection between hub and crown is made dynamic through elastic elements that allow continuous relative rotation within angular limits. This dynamic connection enables precise control of torque transmission and decoupling based on rotational position, avoiding the imprecision of disc clutch mechanisms while maintaining adaptability.
Solution Approach 2:
The mechanical disc clutch system is replaced with an elastic element-based system that uses material elasticity and geometric constraints to achieve decoupling. This substitution eliminates the need for complex clutch mechanisms and improves control precision through inherent elastic properties and angular range limitations.
3Device complexity
If purely single-direction freewheeling systems are used for decoupling, then device complexity is reduced, but adaptability deteriorates
Solution Approach 1:
The static freewheeling mechanism is enhanced with dynamic control through elastic elements that enable bidirectional torque transmission within specific angular ranges. This dynamic capability allows the simple structural design to achieve versatile torque control, transmitting torque in both directions when needed while maintaining decoupling capability.
Solution Approach 2:
The elastic element connection serves multiple functions: it filters vibrations, transmits torque bidirectionally within angular limits, and enables decoupling when angular limits are reached. This multi-functionality allows a simple structural design to replace complex decoupling mechanisms while maintaining adaptability for various operating conditions.
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
The solution provides a compact, cost-effective, and precisely controlled decoupling mechanism that enhances energy efficiency by minimizing energy consumption and optimizing torque transmission in both internal combustion engine and electric motor/generator operations.
Implementation Method 1
multiple arched elastic groups 20 circumferentially arranged in the chamber 15, designed to transmit torque, when deformed, from the hub 2 to the crown 3 within specific angular ranges
Implementation Method 2
an actuator 30 comprising a coupling portion 32 carried by the hub 2 and an actuation portion 33... configured to be selectively coupled by electromagnetic means
Data Source
AI summary
A filtering pulley has a hub configured to be fixed to a shaft for rotation thereabout, a crown mounted coaxial and rotationally free on the hub, and a plurality of elastic groups arranged circumferentially with respect to the hub and to the crown and interposed, each, between a pair of first elements integral with the hub and between a pair of second elements integral with the crown. The first elements have at least two spokes, carried by an actuator that is made of two portions that are selectively geared between them to selectively connect the crown to the hub.