Nested-structure gear pump with movable inner casing for electro-hydrostatic actuator
Yamamoto, Ko Komagata, Mitsuo Kobayashi, Naoki Nakamura, Yoshihiko
Yamamoto, Ko
Komagata, Mitsuo
Kobayashi, Naoki
Nakamura, Yoshihiko
Supervisor
Department
Robotics
Embargo End Date
Type
Journal article
Date
2025
License
Language
English
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Abstract
This study proposes a nested-structure external gear pump with a movable inner casing for an electro-hydrostatic actuator (EHA). Hydraulic actuators provide robustness, high responsiveness, and force controllability. An EHA is a type of hydraulic actuator that consists of a closed-circuit without a servo valve, and has a potentially high backdrivability, making it suitable for use in a robotic system that physically interacts with the environment. However, when downsizing a pump used in EHA for a robotic application, the design of the clearance inside the pump frequently suffers from a trade-off: the clearance should be smaller to reduce internal leakage but larger to reduce friction. At high pressure, the clearance in the radial direction decreases, increasing the friction between the gear teeth and casing. The proposed nested-structure resolves this trade-off by creating a virtually unloaded state for the inner casing while maintaining clearance even at higher pressures. We present the experimental validation of the developed pump.
Citation
K. Yamamoto, M. Komagata, N. Kobayashi, and Y. Nakamura, “Nested-structure gear pump with movable inner casing for electro-hydrostatic actuator,” Advanced Robotics, 2025, doi: 10.1080/01691864.2025.2490600
Source
Advanced Robotics
Conference
Keywords
Robot actuator, Hydraulic pump, Mechanism design
Subjects
Source
Publisher
Taylor & Francis