Feedback mechanism and valve positioner

A valve positioner including:

• a pilot relay which supplies an output pneumatic pressure in accordance with a supplied pneumatic pressure to an operation unit which opens/closes a valve;
• an electrical/pneumatic signal converter which adjusts an output supply pressure to be supplied from said pilot relay to said operation unit on the basis of a control signal;
• a feedback mechanism which detects an actual working amount of an actuating shaft of said valve and outputs a feedback signal;
• and
• a control arithmetic unit which controls said electrical/pneumatic signal converter by outputting the control signal such that a difference between the feedback signal from said feedback mechanism and an input signal becomes zero,
• wherein said valve positioner has
• a feedback pin which displaces interlocked with a motion of a driving shaft of said valve that opens and closes;
• a feedback shaft which pivots interlocked with displacement of said feedback pin;
• a feedback sensor which outputs a feedback signal, to be used for opening/closing said valve, in accordance with a pivoting amount of said feedback shaft, and
• a connecting member which connects said feedback pin and said feedback shaft, said connecting member having a cylindrical first bearing through which said feedback pin is inserted and a cylindrical second bearing through which said feedback shaft is inserted.