Mechanical reverse rotation prevention device for canned motor pump
A reverse rotation prevention device for a canned motor pump includes: a rotor 110 rotating together with a main shaft of a motor; a stator 120 provided to be spaced at a first distance apart from an outer peripheral surface of the rotor 110 ; a plurality of hinges 130 arranged parallel to the main shaft, positioned between the outer peripheral surface of the rotor 110 and an inner peripheral surface of the stator 120 , and placed at a preset interval on a circumference spaced a second distance apart from the outer peripheral surface of the rotor 110 , the second distance being half the first distance; and a plurality of wedges 140 rotatably connected to the plurality of hinges 130 , and rotating in one direction due to centrifugal force according to a flow direction of fluid F provided in a space formed between the rotor 110 and the stator 120.
1 . 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 k 1 and k 2 denote correction factors for respective variables.
2 . The reverse rotation prevention device of claim 1 ,
wherein the plurality of wedges has a longest distance in a cross-section taken along in a direction perpendicular to the plurality of hinges is longer than the first distance.