Wheel-Driven Generator Clutching for Safe Reefer Energy Recovery

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Solution Overview

Problem

Conventional transport refrigeration systems face inefficiencies and safety concerns during emergency stopping maneuvers due to the lack of immediate disengagement of electric generation devices from the wheel and axle, leading to potential mechanical stress and reduced braking effectiveness.

Innovation Solution

A transport refrigeration system incorporating a mechanical interface with a first clutch mechanism for selective engagement and a second overrunning clutch for immediate disengagement during emergency stops, ensuring safe and efficient energy management by controlling the transfer of rotational energy between the wheel/axle and electric generation device.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If the electric generation device is rotatably engaged with the wheel and wheel axle during emergency stopping maneuver, then energy recovery can occur, but the electric generation device can inadvertently drive the wheel and reduce stopping effectiveness

Engineering Contradiction:
Improveenergy recoveryVSAvoidstopping effectiveness
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The mechanical interface is segmented into two distinct clutch mechanisms: a externally controllable first clutch mechanism for selective engagement and an overrunning second clutch mechanism for automatic disengagement. This segmentation allows independent control of engagement and disengagement functions, resolving the contradiction by enabling energy recovery during normal operation while ensuring immediate disengagement during emergency stops to maintain stopping effectiveness.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The dual clutch mechanism acts as an intermediary between the electric generation device and the wheel/axle. The overrunning clutch specifically serves as a safety intermediary that automatically disconnects the power transmission path when the electric generation device's rotational velocity exceeds the wheel's rotational velocity, preventing the generator from driving the wheel during emergency braking while allowing energy recovery during controlled deceleration.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If an externally controllable clutch mechanism is used to disengage the electric generation device, then engagement can be controlled, but there is a delay in control response during emergency stops

Engineering Contradiction:
Improvecontrol responsivenessVSAvoiddisengagement delay
Core Design Contradiction:
Ease of operationVSLoss of time

Solution Approach 1:

The overrunning clutch is designed as a self-actuating mechanism that automatically disengages the electric generation device from the wheel/axle when the rotational velocity of the generator exceeds that of the wheel. This self-service mechanism eliminates the need for external control signals and human reaction time, providing immediate disengagement during emergency stopping maneuvers without any control delay.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces the purely externally controlled mechanical clutch system with a hybrid system that incorporates an overrunning clutch. The overrunning clutch uses mechanical principles (friction, spring force, or centrifugal force) to automatically sense the rotational velocity difference and disengage the connection, substituting electronic control with a direct mechanical response that reacts instantaneously to emergency conditions.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Loss of energy

If the electric generation device is engaged with the wheel during emergency stop, then rotational energy can be recovered, but mechanical stress increases on the mechanical interface

Engineering Contradiction:
Improverotational energy recoveryVSAvoidmechanical interface durability
Core Design Contradiction:
Loss of energyVSStrength

Solution Approach 1:

The overrunning clutch converts the potentially harmful situation of high mechanical stress during emergency braking into a beneficial automatic protection mechanism. When the wheel decelerates faster than the generator during emergency stopping, the rotational velocity difference automatically triggers the overrunning clutch to disengage, protecting the mechanical interface from excessive stress while allowing energy recovery during normal deceleration when stress levels are manageable.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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 system effectively prevents the electric generation device from inadvertently driving the wheel/axle during emergency stops, enhancing safety and reducing mechanical stress, while optimizing energy recovery during normal operations by using a power management module to control the clutch mechanisms based on sensor data.

Implementation Method 1

a second clutch mechanism, wherein the second clutch mechanism is an overrunning clutch configured to disengage the electric generation device from the wheel and/or the wheel axle when a rotational velocity of the electric generation device is greater than a rotational velocity of the wheel and/or wheel axle

Methodology Applied
Scientific EffectRotational velocity comparison:

Implementation Method 2

an electric generation device operably connected through a mechanical interface to at least one of a wheel of the transport refrigeration system and a wheel axle of the transport refrigeration system

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP4147898B1Transport power generator system
Publication Date: 2024.12.18 CARRIER CORP
  • EP4147898B1 patent drawingFigure 1
  • EP4147898B1 patent drawingFigure 2
  • EP4147898B1 patent drawingFigure 3

AI summary

A transport refrigeration system comprising: a transportation refrigeration unit; an energy storage device configured to provide electrical power to the transportation refrigeration unit; and an electric generation device 340 operably connected through a mechanical interface 370 to at least one of a wheel 364 of the transport refrigeration system and a wheel axle 365 of the transport refrigeration system; wherein the mechanical interface comprises: a first clutch mechanism 371 operable to selectively engage the electric generation device with at least one of the wheel and the wheel axle to generate electrical power to charge the energy storage device; and a second clutch mechanism 372, wherein the second clutch mechanism is an overrunning clutch configured to disengage the electric generation device from the wheel and/or the wheel axle when a rotational velocity of the electric generation device is greater than a rotational velocity of the wheel and/or the wheel axle.