Abstract: A fuel pump includes a pump cover at one end portion of the housing, a cover end at the other end portion of the housing, a bearing supported by the cover end and rotatably supporting an end portion of the shaft on the cover end-side. The cover end includes a base part that covers the other end portion, a discharge part that is connected to the base part, a bearing accommodating part which is formed such that a cross-section of the bearing accommodating part perpendicular to a rotation axis of the shaft has an annular shape and which includes an accommodating space accommodating the bearing, and a connection part that connects together the base part and the bearing accommodating part. A length of the connection part is shorter than a length of the base part and a length of the bearing accommodating part, in a direction of the rotation axis.

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 cover end of a fuel pump is formed by resin molding and has a tubular portion, which holds a bearing that is placed along a central axis of the tubular portion and rotatably supports one end portion of a shaft of a motor arrangement. Furthermore, three terminals, which supply three-phase electric power received from an outside to windings on a phase-by-phase basis, are insert molded in the cover end. In the cover end, a first transverse passage, which is formed between the first terminal and the second terminal in a circumferential direction, and a second transverse passage, which is formed between the second terminal and the third terminal in the circumferential direction, are configured into a form of V-shape, which diverges in a radially outer direction, in a view taken in an axial direction.

Abstract: Partitioned chambers of an electric connector, which receive connection terminals electrically connected to windings of a stator, are communicated with an outside of the electric connector through primary communication holes. The primary communication holes are formed to direct at least one of perpendicular directions, each of which is perpendicular to a corresponding one of opening planes of outside openings of the primary communication holes, toward a downside when a central axis of a fuel pump is tilted relative to a vertical direction. In this way, a foreign object, which is accumulated in any of the portioned chambers, can be outputted to the outside through the primary communication hole even when the fuel pump is tilted in any direction.

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 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 drive controller that controls a drive of a motor. The drive controller performs a collision force moderation control during a motor start time, during which a collision force in a collision between a shaft outwall with an impeller hole inwall for a positioning is moderated, by changing a power supply at a stage transition time of transiting from a position detection to a position determination. The maximum value of a first output value during a position detection time is set to be greater than a first threshold that at least causes a rotation number of the motor to yield a detectable induction voltage. A second output value during a position determination time is set to be lower than a second threshold that causes a wear or a breakage of an impeller by the collision force.

Abstract: A fuel pump includes a cylindrical stator having a plurality of windings, a rotor rotatably disposed radially inward of the stator, a shaft integrally rotatable with the rotor, an impeller including a fitting hole to which an end portion of the shaft is fitted, and a balance weight disposed in the impeller. The balance weight is formed so as to be symmetrical about a point of symmetry lying on an axial center of the impeller.

Abstract: A fuel pump includes a shaft integrally rotatable with a rotor, and an impeller including a fitting hole to which the shaft is fitted. The shaft includes shaft contact surfaces which contact flat surfaces that form the fitting hole when the shaft rotates. The shaft contact surfaces include grooves formed to extend in a center axis direction of the shaft.

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 fuel pump includes a pump cover that is provided at one end portion of the housing and includes an inlet port, a cover end that is provided at the other end portion of the housing and includes a discharge port, a bearing that is supported by the cover end and rotatably supports an end portion of the shaft on the cover end-side. The cover end includes a base part that covers the other end portion, a discharge part that is connected to the base part and includes the discharge port, a bearing accommodating part which is formed such that a cross-section of the bearing accommodating part perpendicular to a rotation axis of the shaft has an annular shape and which includes an accommodating space that accommodates the bearing, and a connection part that connects together the base part and the bearing accommodating part.

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: 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 bearing receiving portion includes a receiving space that receives a bearing, which rotatably supports an end portion of a shaft. The bearing receiving portion includes an intermediate inner diameter portion, which receives the end portion of the shaft, and a small inner diameter portion, which includes a column shape space having an inner diameter that is smaller than an outer diameter of the end portion. Fuel in an inside of a housing flows into or flows out relative to the receiving space. When the shaft is moved toward an upside, the fuel, which is accumulated in a space formed by a bottom wall, an inner wall and an end surface, functions as a damper to reduce a relative moving speed of the shaft relative to the bearing receiving portion.