Electric pump

Abstract

An electric pump may comprise a rotating body comprising a rotor and an impeller disposed juxtaposed to the rotor in a rotary shaft direction of the rotor, a stator disposed on an outer circumferential side of the rotor, a easing comprising a fluid passage formed along an outer circumference of the impeller, and configured to store the rotating body and the stator and a loading unit configured to constantly apply force on the rotating body during when the electric pump is operating, wherein the force being for reducing displacement of the rotating body caused by a pressure difference in the fluid passage generated when the electric pump is operating between a low pressure side where a pressure of fluid is low and a high pressure side where the pressure of the fluid is high within the fluid passage.

What is claimed is: 
     
         1 . An electric pump comprising:
 a rotating body comprising a rotor and an impeller disposed juxtaposed to the rotor in a rotary shaft direction of the rotor;   a stator disposed on an outer circumferential side of the rotor;   a casing comprising a fluid passage formed along an outer circumference of the impeller, and configured to store the rotating body and the stator; and   a loading unit configured to constantly apply force on the rotating body during when the electric pump is operating, wherein the force being for reducing displacement of the rotating body caused by a pressure difference in the fluid passage generated when the electric pump is operating between a low pressure side where a pressure of fluid is low and a high pressure side where the pressure of the fluid is high within the fluid passage.   
     
     
         2 . The electric pump as in  claim 1 , wherein
 the loading unit comprises a first configuration, a second configuration, or both of the first and second configurations,   the first configuration is a configuration in which resultant force of magnetic force loaded on an end portion of the rotor on an impeller side is directed from the low pressure side to the high pressure side, and   the second configuration is a configuration in which resultant force of magnetic force loaded on an end portion of the rotor on an opposite side from the impeller is directed from the high pressure side to the low pressure side.   
     
     
         3 . The electric pump as in  claim 2 , wherein
 the loading unit includes a stator and a rotor,   the first configuration includes a configuration in which an area of the stator extending along the end portion of the rotor on the impeller side on the high pressure side is larger than an area of the stator extending along the end portion of the rotor on the impeller side on the low pressure side, and   the second configuration includes a configuration in which an area of the stator extending along the end portion of the rotor on the opposite side from the impeller on the low pressure side is larger than an area of the stator extending along the end portion of the rotor on the opposite side from the impeller on the high pressure side.   
     
     
         4 . The electric pump as in  claim 3 , wherein
 the first configuration includes a configuration in which an end portion of a high pressure-side stator portion positioned on the high pressure side of the stator extends toward the impeller side along the rotary shaft direction than an end portion of a low pressure-side stator portion positioned on the low pressure side of the stator, and   the second configuration includes a configuration in which an end portion of the low pressure-side stator portion on the opposite side from the impeller extends toward the opposite side from the impeller along the rotary shaft direction than an end portion of the high pressure-side stator portion on the opposite side from the impeller.   
     
     
         5 . The electric pump as in  claim 3 , wherein
 the first configuration includes a configuration in which a length of a high pressure-side stator portion extending along an outer circumferential surface of the rotor is longer than a length of a low pressure-side stator portion extending along the outer circumferential surface of the rotor in a cross section vertically intersecting a rotary shaft at the end portion of the rotor on the impeller side, and   the second configuration includes a configuration in which a length of the low pressure-side stator portion extending along the outer circumferential surface of the rotor is longer than a length of the high pressure-side stator portion extending along the outer circumferential surface of the rotor in a cross section vertically intersecting the rotary shaft at the end portion of the rotor on the opposite side from the impeller.   
     
     
         6 . The electric pump as in  claim 2 , wherein
 the load unit includes a stator and a rotor,   the first configuration includes a configuration in which an average gap size between the rotor and a high pressure-side stator portion positioned on the high pressure side of the stator is smaller than an average gap size between the rotor and a low pressure-side stator portion positioned on the low pressure side of the stator at the end portion of the rotor on the impeller side, and   the second configuration includes a configuration in which an average gap size between the rotor and the low pressure-side stator portion is smaller than an average gap size between the rotor and the high pressure-side stator portion at the end portion of the rotor on the opposite side from the impeller.   
     
     
         7 . The electric pump as in  claim 1 , wherein
 the loading unit includes a first magnetic body attached to the rotating body and circumscribing in a circumferential direction of the rotating body, and a second magnetic body attached to a region of the casing that faces the first magnetic body,   the second magnetic body comprises a first magnetic sub-body, a second magnetic sub-body, or both the first and second magnetic sub-bodies,   the first magnetic sub-body is disposed on the high pressure side, and generates magnetic force in a direction that draws the first magnetic body toward the second magnetic body, and   the second magnetic sub-body is disposed on the low pressure side, and generates magnetic force in a direction that presses the first magnetic body toward an opposite side from the second magnetic body.   
     
     
         8 . The electric pump as in  claim 7 , wherein
 the first magnetic body is attached to the impeller   9. The electric pump as in  claim 7 , wherein   the first magnetic body is attached to an end surface of the rotor on the opposite side from the impeller.   
     
     
         10 . The electric pump as in  claim 1 , wherein
 the loading unit includes a circumferential wall that covers the stator and surrounds a circumference of the rotor,   the fluid passage communicates with a gap between the circumferential wall and the rotor,   the loading unit includes a third configuration, a fourth configuration, or both the third and fourth configurations,   the third configuration is a configuration in which a gap between the circumferential wall and the rotor on the low pressure side is larger than a gap between the circumferential wall and the rotor on the high pressure side at the end portion of the rotor on the impeller side, and   the fourth configuration is a configuration in which a gap between the circumferential wall and the rotor on the high pressure side is larger than a gap between the circumferential wall and the rotor on the low pressure side at the end portion of the rotor on the opposite side from the impeller.   
     
     
         11 . The electric pump as in  claim 1 , wherein
 the loading unit includes a facing wall that faces an end surface of the rotor on the opposite side from the impeller,   the fluid passage communicates with a gap between the facing wall and the rotor, and   the loading unit includes a configuration in which a gap between the facing wall and an end surface of the rotor on the opposite side from the impeller that is on the low pressure side is larger than a gap between the facing wall and an end surface of the rotor on the opposite side from the impeller that is on the high pressure side.