Abstract: A motor control device includes: a rotation control determination unit configured to determine whether a motor rotation control to rotate the motor fails; a parameter calculation unit configured to calculate a control failure frequency parameter having a correlation with a frequency of failure in the motor rotation control based on a determination result by the rotation control determination unit; an abnormality determination unit configured to determine whether an abnormality has occurred in the motor based on the control failure frequency parameter; and a stop suppression unit configured to suppress stop of rotation of the motor by changing a motor control parameter to perform the motor rotation control when the abnormality determination unit determines that an abnormality has occurred in the motor.

Abstract: A motor control device includes: a rotation control determination unit configured to determine whether a motor rotation control to rotate the motor fails; a parameter calculation unit configured to calculate a control failure frequency parameter having a correlation with a frequency of failure in the motor rotation control based on a determination result by the rotation control determination unit; and an abnormality determination unit configured to determine whether an abnormality has occurred in the motor based on the control failure frequency parameter.

Abstract: A motor control device configured to control a motor that drives a fuel pump includes a sign detection unit and a vapor suppression unit. The sign detection unit is configured to detect a sign of a vapor lock that is an abnormality in which the fuel pump is unable to discharge a fuel due to a vapor inside the fuel pump. The vapor suppression unit is configured to change a rotation speed of the motor to reduce the vapor inside the fuel pump when the sign detection unit detects the sign of the vapor lock.

Abstract: A fuel pump is connected to a suction filter which is provided with a filter connecting portion having a cylindrical hole and a projecting portion protruding radially inward from an inner peripheral wall of the cylindrical hole. The fuel pump suctions the fuel filtered by the suction filter. The fuel pump is provided with a suction port having multiple suction openings at a side of the suction filter so as to suction the fuel therethrough, and a pump connecting portion provided at outer side of the multiple suction openings and connected with the filter connecting portion. The pump connecting portion has an outer peripheral wall of which outer shape corresponds with a shape of the inner peripheral wall, and a dent portion denting inward from the outer peripheral wall, which the projecting portion is engaged with.

Abstract: A pump control unit controls a fuel pump based on a control target value of an engine. A pump characteristic detection unit acquires a pump characteristic value among pump characteristic values, which indicate an operating state of a fuel pump and include a supplied current to the fuel pump, an applied voltage to the fuel pump, a generated voltage of the fuel pump, and a rotation speed of the fuel pump. A pump characteristic storage unit stores the acquired pump characteristic value together with the control target value. A determination threshold set unit sets a determination threshold value by using at least one of the stored pump characteristic value, the control target value, and a combination of at least two of the control target values. A fuel pump deterioration determination unit determines deterioration of the fuel pump by using the stored pump characteristic value and the determination threshold value.

Abstract: A fuel pump has a pump function of sucking fuel in a fuel tank and discharging fuel, and a detection function of detecting a capacitance correlated to a concentration of alcohol in fuel in the fuel tank. The fuel pump includes a pump main body that is received in the fuel tank to perform the pump function, a housing electrode that covers the pump main body in the fuel tank, and an outside electrode that is located outside of the housing electrode in the fuel tank. A gap is formed between the outside electrode and the housing electrode to give the capacitance.

Abstract: A rotor used for a motor that rotates an impeller of a fuel pump includes a cylindrical bonded magnet that forms a plurality of magnetic poles, an inner core that is a cylindrical component provided inward of the bonded magnet and that has both axial end surfaces exposed to outside, and a rotating shaft that includes a connecting end, which has a pair of flat surfaces parallel to each other and is fitted to the impeller, and that is provided to pass through the inner core inward thereof. A cross section of the connecting end has a centroid coinciding with a rotational axis.

Abstract: An ECU of a fuel pump executes a feedback control to drive a motor part and sets a rotation speed of an impeller to become a rotation speed corresponding to the target fuel pressure. The ECU detects whether a vapor is generated in a fuel of a pump chamber of the fuel pump, based on a fuel pressure detected by a pressure sensor. When a generation of the vapor is detected, the ECU sets a rotation speed of the impeller to be higher than the rotation speed under a normal control for a predetermined time with a result that the vapor in the pump chamber and a fuel flow channel is discharged into a vapor discharge hole. Thus, the vapor of the pump chamber is discharged from the vapor discharge hole to an outside of the fuel pump.

Abstract: An outer wall surface of an output end portion includes a pair of first plane surfaces which are formed at different positions in its circumferential direction. An inner wall surface of a fitting hole includes a pair of second plane surfaces which are formed at different positions in the circumferential direction. A clearance between one of the pair of first plane surfaces and one of the pair of second plane surfaces is made larger from one side toward the other side in an axial direction in a state that a rotary shaft and an impeller are concentric with each other.

Abstract: A screw pump has a male screw accommodation hole and a female screw accommodation hole formed in a pump housing. A male screw member and a female screw member are respectively accommodated in the male screw accommodation hole and the female screw accommodation hole. A male-side clearance is formed in a radial direction between the male screw member and the male screw accommodation hole and a female-side clearance is formed in the radial direction between the female screw member and the female screw accommodation hole. The female-side clearance is made to be larger than the male-side clearance, so that the female screw member can easily move in a direction away from the male screw member to the female-side clearance when any extraneous material is going to be wedged between the male screw member and the female screw member, to thereby prevent a locked condition of the screw members.

Abstract: A fuel pump has a pump function of sucking fuel in a fuel tank and discharging fuel, and a detection function of detecting a capacitance correlated to a concentration of alcohol in fuel in the fuel tank. The fuel pump includes a pump main body that is received in the fuel tank to perform the pump function, a housing electrode that covers the pump main body in the fuel tank, and an outside electrode that is located outside of the housing electrode in the fuel tank. A gap is formed between the outside electrode and the housing electrode to give the capacitance.

Abstract: A fuel pump is connected to a suction filter which is provided with a filter connecting portion having a cylindrical hole and a projecting portion protruding radially inward from an inner peripheral wall of the cylindrical hole. The fuel pump suctions the fuel filtered by the suction filter. The fuel pump is provided with a suction port having multiple suction openings at a side of the suction filter so as to suction the fuel therethrough, and a pump connecting portion provided at outer side of the multiple suction openings and connected with the filter connecting portion. The pump connecting portion has an outer peripheral wall of which outer shape corresponds with a shape of the inner peripheral wall, and a dent portion denting inward from the outer peripheral wall, which the projecting portion is engaged with.

Abstract: A phenolic-resin molding material contains a novolac-type phenolic resin, a hexamethylene tetramin, and an inorganic filler. A total content of a content of the novolac-type phenolic resin and a content of the hexamethylene tetramin is 20 to 55 mass % with respect to an entirety of the phenolic-resin molding material. A content of the inorganic filler is 45 to 80 mass % with respect to the entirety of the phenolic-resin molding material. A content of the hexamethylene tetramin is 17 to 26 pts.mass with respect to an entirety of the novolac-type phenolic resin.

Abstract: An impeller for a fuel pump is molded by a molding material containing a phenolic resin and an inorganic filler. A content at a minimum spin-spin relaxation time is 70% or higher with respect to a whole when approximating a free induction decay curve, which is obtained by Solid Echo Method in a pulse NMR measurement at 90° C., with a sum of relaxation curves of three components. The content at the minimum spin-spin relaxation time corresponds to a content of a portion of the phenolic resin, which forms the impeller for the fuel pump, where a cross-linking reaction is caused. A swelling amount of the impeller due to a liquid containing a fuel and water decreases as a crosslink density of the phenolic resin increases. The swelling amount of the impeller in the present disclosure is smaller than the swelling amount of an impeller molded by PPS resin.

Abstract: A microcomputer of a drive control device for controlling the driving of a brushless motor has a positioning part and a torque acceleration control unit. The positioning unit controls the power to be supplied to the windings, to thereby position the rotor at a drive start position which is a position of the rotor relative to the stator at which the drive control of the brushless motor can start, before starting the drive control of the brushless motor. The torque acceleration control unit controls the power to be supplied to the windings so that a torque acceleration falls within a predetermined range that the collision stress generated when the outer wall of the end of the shaft collides with the inner wall of the hole of an impeller (rotating member) is equal to or smaller than a predetermined value, when the rotor is positioned.

Abstract: A rotor used for a motor that rotates an impellor of a fuel pump includes a cylindrical bonded magnet that forms a plurality of magnetic poles, an inner core that is a cylindrical component provided inward of the bonded magnet and that has both axial end surfaces exposed to outside, and a rotating shaft that includes a connecting end, which has a pair of flat surfaces parallel to each other and is fitted to the impeller, and that is provided to pass through the inner core inward thereof. A cross section of the connecting end has a centroid coinciding with a rotational axis.

Abstract: An outer wall surface of an output end portion includes a pair of first plane surfaces which are formed at different positions in its circumferential direction. An inner wall surface of a fitting hole includes a pair of second plane surfaces which are formed at different positions in the circumferential direction. A clearance between one of the pair of first plane surfaces and one of the pair of second plane surfaces is made larger from one side toward the other side in an axial direction in a state that a rotary shaft and an impeller are concentric with each other.

Abstract: A fuel pump includes a motor (20), an impeller (39) that includes a fitting hole (44; 71) fitted to an output end portion (37) of a rotary shaft (31) of the motor (20), and a case (48) that includes a pump chamber (41) receiving the impeller (39), a suction hole (13) passing through the case (48) from the pump chamber (41) to one side in an axial direction of the rotary shaft (31), and a discharge hole (47) passing through the case (48) from the pump chamber (41) to the other side in the axial direction. An outer wall surface of the output end portion (37) includes a pair of first plane surfaces (51, 52) that are parallel to each other.

Abstract: A permanent magnet of a rotor core of a rotor includes a first recess and a second recess, which are formed in an outer wall to correct a dynamic balance of the rotor. The permanent magnet is a bonded magnet that is formed by molding a mixture material, which is a mixture of resin and magnetic powder. The first recess and the second recess are formed at the time of molding the permanent magnet. Furthermore, the first recess and the second recess are formed at two axial ends, respectively, of the permanent magnet.

Abstract: A rotor of a brushless motor used in a fuel pump includes a permanent magnet having first and second ends that are configured to have a thickness ratio so that a degree of margin of those ends, which is a difference between an allowable stress and a temperature stress due to expansion and contraction of a rotor core caused by a temperature change is equal to or greater than a preset value. As a result, a cracking of the permanent magnet on the both ends that is caused by repeated expansions and contractions of the rotor core is prevented.