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Energy Harvesting from Upper-Limb Pulling Motions for Miniaturized Human-Powered Generators.

Yeo J, Ryu MH, Yang Y - Sensors (Basel) (2015)

Bottom Line: This study proposes a portable human-powered generator which is designed to obtain mechanical energy from an upper limb pulling motion for improved human motion economy as well as efficient human-mechanical power transfer.Its small form factor (50 mm × 32 mm × 43.5 mm, 0.05 kg) and the substantial electricity produced verify the effectiveness of the proposed method in the utilization of human power.It is expected that the developed generator could provide a mobile power supply.

View Article: PubMed Central - PubMed

Affiliation: Healthcare Engineering, Chonbuk National University, Deokjin-dong Jeonju 664-14, Korea. yeojjin85@jbnu.ac.kr.

ABSTRACT
The human-powered self-generator provides the best solution for individuals who need an instantaneous power supply for travel, outdoor, and emergency use, since it is less dependent on weather conditions and occupies less space than other renewable power supplies. However, many commercial portable self-generators that employ hand-cranking are not used as much as expected in daily lives although they have enough output capacity due to their intensive workload. This study proposes a portable human-powered generator which is designed to obtain mechanical energy from an upper limb pulling motion for improved human motion economy as well as efficient human-mechanical power transfer. A coreless axial-flux permanent magnet machine (APMM) and a flywheel magnet rotor were used in conjunction with a one-way clutched power transmission system in order to obtain effective power from the pulling motion. The developed prototype showed an average energy conversion efficiency of 30.98% and an average output power of 0.32 W with a maximum of 1.89 W. Its small form factor (50 mm × 32 mm × 43.5 mm, 0.05 kg) and the substantial electricity produced verify the effectiveness of the proposed method in the utilization of human power. It is expected that the developed generator could provide a mobile power supply.

No MeSH data available.


Related in: MedlinePlus

3-D designed structure of the pulling energy harvester.
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sensors-15-15853-f004: 3-D designed structure of the pulling energy harvester.

Mentions: In Figure 1, it is supposed that the high speed rotating body is a key to the large amount of power production from the pulling motion. Therefore, since it is essential to decrease the torque required for rotating the magnet rotor, air-cored coils replaced the usual metal-cored coils in the APMM to eliminate the cogging torque. The 3-D detail of a designed pulling energy harvester is provided in Figure 4, which shows the arrangement of its components. The small bobbin is mechanically linked to the magnet rotor via a one-way clutch and high-ratio gear. A metal string is wound on the bobbin and a spiral spring connects the bobbin to shaft A for rewinding the string. The one-way clutch enables the pulling force to produce a unidirectional rotation of the magnet rotor by disengaging the bobbin from the gear during the rewinding intervals, during which the bobbin rotates in the opposite direction to rewind the string. Additionally, it is expected that the removal of cogging will allow the inertial mass augmented by 12 magnets placed in the disc rotor to serve the purpose of preserving its rotation during the rewinding intervals between consecutive pulling cycles, similar to the flywheel employed in large wind turbine generators.


Energy Harvesting from Upper-Limb Pulling Motions for Miniaturized Human-Powered Generators.

Yeo J, Ryu MH, Yang Y - Sensors (Basel) (2015)

3-D designed structure of the pulling energy harvester.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4541857&req=5

sensors-15-15853-f004: 3-D designed structure of the pulling energy harvester.
Mentions: In Figure 1, it is supposed that the high speed rotating body is a key to the large amount of power production from the pulling motion. Therefore, since it is essential to decrease the torque required for rotating the magnet rotor, air-cored coils replaced the usual metal-cored coils in the APMM to eliminate the cogging torque. The 3-D detail of a designed pulling energy harvester is provided in Figure 4, which shows the arrangement of its components. The small bobbin is mechanically linked to the magnet rotor via a one-way clutch and high-ratio gear. A metal string is wound on the bobbin and a spiral spring connects the bobbin to shaft A for rewinding the string. The one-way clutch enables the pulling force to produce a unidirectional rotation of the magnet rotor by disengaging the bobbin from the gear during the rewinding intervals, during which the bobbin rotates in the opposite direction to rewind the string. Additionally, it is expected that the removal of cogging will allow the inertial mass augmented by 12 magnets placed in the disc rotor to serve the purpose of preserving its rotation during the rewinding intervals between consecutive pulling cycles, similar to the flywheel employed in large wind turbine generators.

Bottom Line: This study proposes a portable human-powered generator which is designed to obtain mechanical energy from an upper limb pulling motion for improved human motion economy as well as efficient human-mechanical power transfer.Its small form factor (50 mm × 32 mm × 43.5 mm, 0.05 kg) and the substantial electricity produced verify the effectiveness of the proposed method in the utilization of human power.It is expected that the developed generator could provide a mobile power supply.

View Article: PubMed Central - PubMed

Affiliation: Healthcare Engineering, Chonbuk National University, Deokjin-dong Jeonju 664-14, Korea. yeojjin85@jbnu.ac.kr.

ABSTRACT
The human-powered self-generator provides the best solution for individuals who need an instantaneous power supply for travel, outdoor, and emergency use, since it is less dependent on weather conditions and occupies less space than other renewable power supplies. However, many commercial portable self-generators that employ hand-cranking are not used as much as expected in daily lives although they have enough output capacity due to their intensive workload. This study proposes a portable human-powered generator which is designed to obtain mechanical energy from an upper limb pulling motion for improved human motion economy as well as efficient human-mechanical power transfer. A coreless axial-flux permanent magnet machine (APMM) and a flywheel magnet rotor were used in conjunction with a one-way clutched power transmission system in order to obtain effective power from the pulling motion. The developed prototype showed an average energy conversion efficiency of 30.98% and an average output power of 0.32 W with a maximum of 1.89 W. Its small form factor (50 mm × 32 mm × 43.5 mm, 0.05 kg) and the substantial electricity produced verify the effectiveness of the proposed method in the utilization of human power. It is expected that the developed generator could provide a mobile power supply.

No MeSH data available.


Related in: MedlinePlus