Eccentric valve

An eccentric valve comprising:

• a valve seat including a valve hole and a seat surface formed at an edge of the valve hole;
• a valve element formed with a seal surface on an outer periphery corresponding to the seat surface;
• a rotary shaft integrally provided with the valve element to rotate the valve element, and
• the rotary shaft having a central axis extending in parallel to a radial direction of the valve element, the central axis of the rotary shaft being positioned eccentrically from a center of the valve hole in another radial direction of the valve hole, and the seal surface being positioned eccentrically from the central axis of the rotary shaft toward an extending direction of a central axis of the valve element,
• wherein the eccentric valve further comprises:
• a drive mechanism configured to generate a drive force to rotate the rotary shaft in a valve opening direction;
• a drive force receiving part integrally provided with the rotary shaft and configured to receive the drive force;
• a bearing placed in a position between the valve element and the drive force receiving part in a direction of the central axis of the rotary shaft to support the rotary shaft;
• and
• a return spring configured to generate a return spring force to rotate the rotary shaft in a valve closing direction,
• wherein, during non-operation of the drive mechanism, the eccentric valve generates a separating-direction urging force to cause the rotary shaft to incline about the bearing serving as a fulcrum and urge the valve element in a direction away from the valve seat, the separating-direction urging force being a force caused by the return spring force and acting in a direction perpendicular to a central axis of the bearing, and
• either the valve element or the valve seat is provided with a sealing member to seal between the valve element and the valve seat during non-operation of the drive mechanism.