To provide a hydraulic clutch having excellent transmission efficiency and a simple device structure, and to provide a hydraulic automatic transmission therewith.
This hydraulic clutch 10 has: a drive side circumscribed gear pump gear 13 fixed to an input side main shaft 101; an output rotor 11 having an internal space 127 accommodating the drive side circumscribed gear pump gear 13; and a freely-rotating circumscribing gear pump gear 14 disposed in the internal space 127 of the output rotor 11 apart from the drive side circumscribed gear pump gear 13 at an arbitrary gear center distance. A state that the output rotor 11 rotates together with the freely-rotating circumscribing gear pump gear 14 according to rotation of the drive side circumscribed gear pump gear 13 and a state that the freely-rotating circumscribing gear pump gear 14 idles to the output rotor 11 according to the rotation of the drive side circumscribed gear pump gear 13 not to cause the rotation of the output rotor 11 are changed over.
Hiroyuki Nagai
Junpei Okada
Hirohito Katsunuma
Kiyohiro Suzuki