| 摘要 |
A pressure transmission medium contains an ester or an ether having two or more ring structures of an aromatic ring or a saturated naphthenic ring as a pressure transmission medium base oil. The pressure transmission medium that exhibits low energy loss due to compression, excellent response in a hydraulic circuit, energy-saving, high-speed operation and high precision of control in a hydraulic circuit, a low viscosity and a low churning resistance, and a hydraulic device can be provided. |
