Patent ID: 8801411
Filing Date: 2014-08-12
Classification: F04C

Abstract:
1. An internal-gear type fluid device comprising: a housing provided with an inlet port and an outlet port; an outer rotor rotatably housed in the housing; and an inner rotor installed inside the outer rotor, wherein a plurality of fluid chambers defined between the outer rotor and the inner rotor move to be subjected to an inlet stroke in which the fluid chambers communicate with the inlet port thereby enlarging the chamber volume, an outlet stroke in which the fluid chambers communicate with the outlet port thereby reducing the chamber volume, and a confinement stroke which is positioned between the inlet stroke and the outlet stroke and in which the chamber volume is at a maximum; at least either one of an inner circumferential portion of the outer rotor and an outer circumferential portion of the inner rotor has guide teeth constituted by inner teeth or outer teeth continuous in a circumferential direction, the guide teeth being configured to have a width less than that of the rotor, and vane portions are formed to extend in a width direction from tooth tip portions of the guide teeth to an end surface of the rotor; before a volume of a fluid chamber in the confinement stroke reaches a maximum, the fluid chamber in the confinement stroke and a fluid chamber in the intake stroke communicate with each other via a space between the vane portions disposed with a predetermined spacing in the circumferential direction, but the fluid chamber in the confinement stroke and the fluid chamber in the outlet stroke are cut off from each other by the vane portion; when the volume of the fluid chamber in the confinement stroke reaches the maximum, the fluid chamber in the confinement stroke and the fluid chamber in the outlet stroke are cut off from each other by the vane portion and the fluid chamber in the confinement stroke and the fluid chamber in the inlet stroke are cut off from each other by the vane portion; and after the volume of fluid chamber in the confinement stroke reaches the maximum, the fluid chamber in the confinement stroke and the fluid chamber in the inlet stroke are cut off from each other by the vane portion, but the fluid chamber in the confinement stroke and the fluid chamber in the outlet stroke communicate with each other via the space between the vane portions.