Patent ID: 7744434
Filing Date: 2010-06-29
Classification: B63H

Abstract:
1. An oscillating-foil type underwater propulsor with a joint, the propulsor comprising: a streamline foil having a foil surface being parallel to a water surface and a span length of at least twice as long as an average chord length of the streamline foil; and a heaving mechanism undergoing heaving motion perpendicular to a propulsion direction of the propulsor and having a transmission section, the heaving mechanism comprising: a rotational cylinder being hollow inside and having an opening at the bottom, the rotational cylinder being configured as a body of the heaving mechanism; a first permanent magnet provided around the top of the inside of the rotational cylinder; a second permanent magnet provided around the bottom of the inside of the rotational cylinder; a coil provided around the inside of the rotational cylinder and between the first permanent magnet and the second permanent magnet; and a third permanent magnet provided inside the coil and having a bottom attached to the transmission section, wherein the transmission section is configured to extend outwards from the opening to pivotally connect the streamline foil, wherein the transmission section is pivotally connected to the streamline foil to form a joint, the joint being provided at the middle of the span length and having a rotation center located within a circular area, which has a radius of one third of the average chord length and is centered at a point one third of the average chord length ahead of a lifting center of the streamline foil.