Support structure of valve shaft for butterfly valve

A butterfly valve assembly comprising:

• a valve shaft supported by a bearing so as to rotate around its longitudinal axis and having a first end and a second end;
• an actuator connected to said first end of said valve shaft;
• and
• a valve-opening sensor connected to said second end of said valve shaft and having a return spring therein, thereby said return spring restricting said valve shaft in its movement within said bearing.

A swirl control valve assembly, having an intake air passage connected to an internal combustion engine, comprising:

• a valve shaft supported by bearings at a first end and a second end thereof so as to rotate around its longitudinal axis;
• a valve body attached to said valve shaft and said valve body being disposed on said intake air passage;
• a first linkage device having a first arm that is fixed to said first end of said valve shaft and rotates together therewith, wherein said first arm has an extended end that extends perpendicular to said longitudinal axis of said valve shaft;
• a second linkage device having a second arm that is fixed to said second end of said valve shaft and rotates together therewith, wherein said second arm has an extended end that extends perpendicular to said longitudinal axis of said valve shaft;
• an actuator connected to said extended end of said first linkage device;
• and
• a valve-opening sensor connected to said extended end of said second linkage device and having a return spring therein that applies a force perpendicular to said longitudinal axis of said valve shaft.