Power Modulating Device for Access Drive Speed Regulation
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Solution Overview
Problem
Current power train configurations in systems like front end accessory drives (FEAD) often result in inefficiencies due to accessories operating outside their optimal speed range, leading to wasted energy and oversizing of components, as they are forced to operate at speeds proportional to the prime mover, rather than at their efficiency-optimizing speeds.
Innovation Solution
The implementation of a power modulating device with a variable planetary torque/speed regulator, including tiltable planet-leg assemblies and a control mechanism with a stepper motor, allows for the adjustment of the speed and torque transfer between a prime mover and driven devices, ensuring they operate within their optimal efficiency ranges.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a direct coupling is used to transfer power from the power source to the driven device, then the structure is simple, but the driven device cannot operate at its optimal speed range when the power source operates outside its optimal speed range
Solution Approach 1:
The patent employs a continuously variable transmission (CVT) mechanism that dynamically adjusts the speed ratio between the power source and driven device. The CVT allows the driven device to operate at its optimal speed range regardless of the power source speed, resolving the contradiction by making the coupling adaptive rather than fixed.
Solution Approach 2:
The patent introduces a power modulating device as an intermediary between the power source and driven device. This mediator component (CVT) decouples the direct speed relationship, allowing independent optimization of both power source and driven device operating ranges while managing power transfer efficiently.
2Adaptability or versatility
If accessories are oversized to handle the full speed and torque ranges, then they can operate across all conditions, but the component size and weight increase
Solution Approach 1:
The CVT enables accessories to operate within their optimal speed range dynamically, allowing them to be sized for optimal performance rather than maximum capacity. This resolves the contradiction by enabling adaptability through continuous speed adjustment rather than through oversized components.
3Device complexity
If accessories operate at speeds proportional to the prime mover, then the coupling is simple, but energy efficiency decreases when accessories operate outside their optimal speed range
Solution Approach 1:
The patent implements a dynamic speed control system through the CVT that continuously adjusts the speed ratio to maintain accessory operation within their optimal efficiency range. This resolves the contradiction by prioritizing energy efficiency over coupling simplicity, using a modulating device to eliminate energy waste.
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 enables accessories to operate at their most efficient speeds across the engine's operating range, reducing energy waste, extending their service life, and improving fuel economy by allowing smaller, lighter components and more flexible packaging.
Implementation Method 1
a control mechanism with a stepper motor
Implementation Method 2
variable planetary torque/speed regulator
Data Source
AI summary
Embodiments are directed to a front end accessory drive (FEAD) and power modulating devices (PMD) which can be used in a FEAD. In one embodiment, a continuously variable transmission (CVT) is coupled directly to a crankshaft of a prime mover, and the CVT is used to regulate the speed and/or torque delivered to an accessory. A compound drive device includes a motor/generator subassembly cooperating with a CVT subassembly to provide a motor functionality with torque multiplication or division, or alternatively, a generator functionality with torque multiplication or division. In some embodiments, a FEAD includes a PMD having a sun shaft configured to couple to a sun of the PMD and to an electric motor component, such as an electrical armature or an electrical field. In one embodiment, the electrical armature the electrical field are placed concentrically and coaxially and configured to rotate relative to one another in opposite directions.