Mechanical reverse rotation prevention device for canned motor pump

A reverse rotation prevention device comprising:

• a rotor;
• a stator provided to be spaced at a first distance apart from an outer peripheral surface of the rotor;
• a plurality of hinges positioned between the outer peripheral surface of the rotor and an inner peripheral surface of the stator, and placed at a preset interval on a circumference spaced a second distance apart from the outer peripheral surface of the rotor, the second distance being half the first distance;
• a plurality of wedges rotatably connected to the plurality of hinges, and rotating in one direction due to centrifugal force according to a flow direction of fluid provided in a space formed between the rotor and the stator;
• and
• a sensor unit for monitoring a status of the plurality of wedges and the rotor,
• wherein during normal rotation, a gap is formed between each of plurality of wedges and the rotor so that fluid passes therethrough, and
• during reverse rotation, one end of each of the plurality of wedges returns to a position where to contact the outer peripheral surface of the rotor by a center of gravity provided at one point of a corresponding one of the plurality of wedges, while the other end of the corresponding one of the plurality of wedges contacts the inner peripheral surface of the stator, thereby eliminating the gap to limit the reverse rotation of the rotor,
• wherein the sensor unit measures a rotational angle of each of the plurality of wedges and a rotational speed of the rotor, and detects wear and status changes through comparison with a preset normal operating state,
• wherein the status change is configured to generate a warning signal based on a wear index M calculated according to the following [Equation 1],
• wherein the warning signal is generated when the M exceeds a threshold value Mth,
• M
• =
• Δθ
• ×
• k
• 1
• +
• Δ
• ⁢
• v
• ×
• k
• 2
• [
• Equation
• ⁢
• 1
• ]
• where M denotes a wear index, Δθ denotes a change in rotational angle of each of the plurality of wedges, Δv denotes a change in speed of the rotor, and k1 and k2 denote correction factors for respective variables.