US20120051954A1

US20120051954A1 - Fuel pump

Info

Publication number: US20120051954A1
Application number: US13/207,710
Authority: US
Inventors: Rihito ASAI; Yoshitaka Wakamatsu; Hideki Koyama; Motoya Ito; Toshitake Yaura
Original assignee: Denso Corp
Current assignee: Denso Corp
Priority date: 2010-08-31
Filing date: 2011-08-11
Publication date: 2012-03-01
Also published as: JP2012055054A; CN102383986A

Abstract

A fuel pump includes a pump part, a motor part, a motor casing, a motor cover, a terminal, and an electric connector part. The terminal is electrically connectable to an external connector for electricity supply. The electric connector part is disposed at an end portion of the motor cover located on the opposite side from a fitted end of the motor cover which is fitted with a housing, and includes a side surface which is slidably in contact with the external connector to determine a fitting position of the electric connector part relative to the external connector, a bottom face from which the terminal rises up, and an opening which is formed on the side surface to communicate between inside and outside of the electric connector part. The bottom face is an inclined surface whose height becomes lower in a direction from generally a center of the motor cover toward the opening.

Description

CROSS REFERENCE TO RELATED APPLICATION

This application is based on and incorporates herein by reference Japanese Patent Application No. 2010-194456 filed on Aug. 31, 2010.

BACKGROUND OF THE INVENTION

1. Field of the Invention
The present invention relates to a fuel pump that drives its pump part by driving force of its motor part to suction and pressurize fuel.
2. Description of Related Art
A fuel pump that supplies fuel to an internal combustion engine is known. The fuel pump pressurizes fuel suctioned from a fuel tank by its pump part, and supplies the fuel to the engine. In the fuel pump, an electric current supplied via its electric connector part flows through a coil, so that a rotor, around which the coil is wound, rotates to drive the pump part. In JP-A-2008-243569, by changing a shape of a resin member that supports a terminal of an electric connector part, a corrosion or short circuit of the terminal which is caused due to the residue of fuel inside the electric connector part is prevented.
In the electrical connector described in JP-A-2008-243569, an opening for discharging the fuel that remains in the electric connector part into the outside is provided on a side surface of the electric connector part. However, if fuel remains away from the opening, or if the residual fuel becomes high-viscosity liquid as a result of the evaporation of its volatile matter content, the discharge of fuel from the opening becomes difficult, and they remain inside the electric connector part. Particularly, because the liquid, whose impure substance has been condensed due to the evaporation of volatile matter content, exhibits high conductivity, the terminal corrodes by a leak current between both poles, and eventually damage of the terminal is caused.

SUMMARY OF THE INVENTION

The present invention addresses at least one of the above disadvantages.
According to the present invention, there is provided a fuel pump including a pump part, a motor part, a motor casing, a motor cover, a terminal, and an electric connector part. The pump part includes a rotation member configured to suction and pressurize fuel. The motor part includes a rotor coupled with a rotating shaft of the rotation member to be capable of rotating the rotation member, a commutator rotated together with the rotor to rectify an electric current supplied to the rotor, and a housing accommodating the rotor and the commutator. The motor casing supports one end of the rotating shaft of the rotation member. The motor cover is disposed at one end of the motor part in an axial direction thereof and is fitted together with the housing so as to fix the motor casing. The terminal is disposed at an end portion of the motor cover located on an opposite side from a fitted end of the motor cover, which is fitted with the housing. The terminal is electrically connectable to an external connector for electricity supply. The electric connector part is disposed at the end portion of the motor cover located on the opposite side from the fitted end of the motor cover, and includes a side surface which is slidably in contact with the external connector to determine a fitting position of the electric connector part relative to the external connector, a bottom face from which the terminal rises up, and an opening which is formed on the side surface to communicate between inside and outside of the electric connector part. The bottom face is an inclined surface whose height becomes lower in a direction from generally a center of the motor cover toward the opening.
According to the present invention, there is also provided a fuel pump including a pump part, a motor part, a motor casing, a motor cover, a terminal, and an electric connector part. The pump part includes a rotation member configured to suction and pressurize fuel. The motor part includes a rotor coupled with a rotating shaft of the rotation member to be capable of rotating the rotation member, a commutator rotated together with the rotor to rectify an electric current supplied to the rotor, and a housing accommodating the rotor and the commutator. The motor casing supports one end of the rotating shaft of the rotation member. The motor cover is disposed at one end of the motor part in an axial direction thereof and is fitted together with the housing so as to fix the motor casing. The terminal is disposed at an end portion of the motor cover located on an opposite side from a fitted end of the motor cover, which is fitted with the housing. The terminal is electrically connectable to an external connector for electricity supply. The electric connector part is disposed at the end portion of the motor cover located on the opposite side from the fitted end of the motor cover, and includes a side surface which is slidably in contact with the external connector to determine a fitting position of the electric connector part relative to the external connector, a bottom face from which the terminal rises up, and an opening which is formed on the side surface to communicate between inside and outside of the electric connector part. The bottom face includes a groove in a direction from generally a center of the motor cover toward the opening, the groove connecting to the opening.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention, together with additional objectives, features and advantages thereof, will be best understood from the following description, the appended claims and the accompanying drawings in which:

FIG. 1 is a sectional view roughly illustrating a fuel pump in accordance with a first embodiment of the invention;

FIG. 2 is a sectional view taken along a line II-II in FIG. 1 for illustrating enlarged vicinity of a brush;

FIG. 3A is a top view illustrating a motor cover of the fuel pump in accordance with the first embodiment;

FIG. 3B is a front view of the motor cover viewed from a direction of an arrow IIIB in FIG. 3A;

FIG. 3C is a sectional view taken along a line IIIC-IIIC in FIG. 3A;

FIG. 4 is a sectional view taken along a line IV-IV in FIG. 3A for illustrating enlarged vicinity of a bottom face of an electric connector part;

FIG. 5 is a perspective view of a cross-section taken along a line V-V in FIG. 3B for illustrating the motor cover of the fuel pump in accordance with the first embodiment;

FIG. 6A is a top view illustrating a motor cover of a fuel pump in accordance with a second embodiment of the invention;

FIG. 6B is a front view of the motor cover viewed from a direction of an arrow VIB in FIG. 6A;

FIG. 6C is a sectional view taken along a line VIC-VIC in FIG. 6A; and

FIG. 7 is a sectional view taken along a line VII-VII in FIG. 6A for illustrating enlarged vicinity of a bottom face of an electric connector part.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments of the invention will be described below with reference to the accompanying drawings.

First Embodiment

A fuel pump 10 of a first embodiment of the invention is illustrated in FIG. 1. This fuel pump 10 is an in-tank pump that is disposed in a fuel tank (not shown) of a vehicle. The fuel pump 10 supplies fuel inside the fuel tank to an engine. The fuel pump 10 includes a pump part 12 that pressurizes the suctioned fuel, and a motor part 14 that drives the pump part 12. The motor part 14 is a direct-current motor with a brush. The fuel pump 10 includes a housing 16 having a generally cylindrical shape. A permanent magnet 18 is disposed annularly in the circumferential direction on an inner wall surface of the housing 16. A rotor 20 is disposed radially inward of the permanent magnet 18 concentrically with the annular permanent magnet 18.
The pump part 12 includes a casing main body 31, a casing cover 32, and an impeller 33 which is a rotation member. The casing main body 31 and the casing cover 32 define a generally C-shaped pump passage 34. The impeller 33 is accommodated rotatably between the casing main body 31 and the casing cover 32. The casing main body 31 and the casing cover 32 are formed by, for example, die casting of aluminum.
The casing main body 31 is fixed in one end side of the housing 16 in an axial direction thereof by press fitting. A pump part side bearing 35 that rotatably supports a shaft 21, which is connected to the impeller 33, is disposed at a central part of the casing main body 31.
The casing cover 32 is fixed to one end portion of the housing 16 by calking, with the casing main body 31 covered in the cover 32. A thrust bearing 36 that limits axial displacement of the shaft 21 is fixed at a central part of the casing cover 32. The casing cover 32 has a fuel inlet 38.
A motor casing 41 and a motor cover 42 are disposed at the other end portion of the housing 16, i.e., on the opposite side of the housing 16 from the casing main body 31 and the casing cover 32. The motor casing 41 is located between the motor cover 42 and the housing 16. The motor casing 41 includes a connecting passage 44 that connects together a pump chamber 22 and a fuel passage 43 of the motor cover 42. The motor casing 41 defines a brush accommodating chamber 45 which accommodates a brush 70 such that the brush 70 can be reciprocated in its axial direction, as illustrated in FIG. 2. The motor casing 41 defines the brush accommodating chamber 45, in which the brush 70 is accommodated. The motor casing 41 accommodates the brush 70, and a compression spring 75 in its brush accommodating chamber 45.
As illustrated in FIG. 1, the motor cover 42 includes a fuel discharge part 46 and an electric connector part 50 radially outward of the shaft 21. The motor cover 42 is fixed to the housing 16 by calking. The fuel discharge part 46 includes the fuel passage 43 and a pressure regulating valve 48. The fuel passage 43 is opened or closed by a valve member 49 of the pressure regulating valve 48. When the pressure of fuel inside the fuel pump 10 becomes larger than a predetermined value, the valve member 49 opens the fuel passage 43.
Terminals 60, 61 are provided for the electric connector part 50, which is connected to the outside of the fuel pump 10. As illustrated in FIG. 2, the terminals 60, 61 are electrically connected to a pigtail 71 via a choking coil 72 and a brush terminal 73. The pigtail 71 is electrically connected to a side surface of the surfaces, which constitute the brush 70, that is located on the opposite side from a rotation center of the shaft 21.
As illustrated in FIG. 1, the rotor 20 is rotatably accommodated inside the housing 16. One end portion of the shaft 21, which is integrated with the rotor 20, is rotatably supported by the pump part side bearing 35 in its radial direction; and the other end portion of the shaft 21 is rotatably supported by a motor part side bearing 37 in the radial direction. A winding wire that constitutes a coil 23 is wound around an outer peripheral surface of the core 25, which is fixed to the shaft 21. A commutator 80 is formed in the shape of a circular disk, and disposed above the rotor 20. More specifically, the commutator 80 is located at an end portion of the rotor 20 on its opposite side from the pump part 12.
The electric connector part 50 will be described in detail. The electric connector part 50 is provided on the opposite side of the center of the motor cover 42 from the fuel discharge part 46 as illustrated in FIGS. 3A to 3C. The electric connector part 50 has a recessed shape with a bottom because of its side surfaces 501, 502, 503, 504, which are slidably in contact with an external connector for electricity supply to determine a fitting position between the electricity supply connector and the electric connector part 50, and its bottom face 505, from which from which the terminals 60, 61 are exposed to rise up. The electric connector part 50 is provided with an opening 57 for the external connector, so as to be fitted together to the external electricity supply connector. A direction of the opening 57 for the external connector is an upward direction which is the same direction as the direction of an opening of the fuel discharge part 46. Arrows indicating the upward and downward directions in FIGS. 3A to 4 illustrate upward and downward directions with the fuel pump 10 disposed in the fuel tank.
As illustrated in FIG. 4, an interior portion of the electric connector part 50 is divided into three parts: a terminal part 51 and two communication parts 53, 55 by a shape of the bottom face 505. The terminal part 51 is located at generally the center of the electric connector part 50. A terminal part bottom face 52 that serves as a bottom face of the terminal part 51 is formed generally parallel to a plane perpendicular to the upward and downward directions. On the terminal part bottom face 52, the terminals 60, 61 for receiving the electric power supply from the outside are disposed at intervals to pass through the terminal part bottom face 52 in the upward and downward directions.
The communication parts 53, 55 are formed at both ends of the terminal part 51 in a tangential direction of the motor cover 42 to be connected to the terminal part 51. As illustrated in FIG. 3C, a communication part bottom face 54 serving as a bottom face of the communication part 53 is an inclined surface from the center of the motor cover 42 toward an opening 58. As well, a communication part bottom face 56 serving as a bottom face of a communication part 55 located on the opposite side of the terminal part 51 from the communication part 53 is an inclined surface from the center of the motor cover 42 toward an opening 59. Heights of the communication part bottom faces 54, 56 become lower from the center of the motor cover 42 toward the openings 58, 59. On the other hand, height of the terminal part bottom face 52 does not change regardless of its distance from the center of the motor cover 42 as described above. Accordingly, as illustrated in FIG. 5, level differences 531, 551 are formed respectively between the terminal part bottom face 52 and the communication part bottom faces 54, 56. Widths of the level differences 531, 551 become larger in a direction away from the center of the motor cover 42.
As illustrated in FIG. 3B, the two generally rectangular openings 58, 59 are formed on an outer wall of the electric connector part 50. The openings 58, 59 communicate between the inside and outside of the electric connector part 50. The openings 58, 59 are formed on radially outward extension lines of the communication parts 53, 55, and the communication parts 53, 55 and the openings 58, 59 are connected together. The openings 58, 59 are formed such that the heights of the communication part bottom faces 54, 56, and heights of lower ends of the openings 58, 59 coincide with each other.
Operation of the fuel pump 10 of the first embodiment will be described. An electric current supplied to the terminal 60 from a power source (not shown) is fed to the commutator 80 through the brush terminal 73, the pigtail 71, and the brush 70. The electric current fed into the commutator 80 is supplied to the coil 23 of the rotor 20. Upon rotation of the rotor 20 by the electric current supplied to the coil 23, the impeller 33 rotates together with the rotor 20 and the shaft 21. When the impeller 33 rotates, fuel is suctioned into the pump passage 34 through the fuel inlet 38. The fuel suctioned into the pump passage 34 is discharged from the pump passage 34 into the pump chamber 22 as a result of application of kinetic energy to the fuel by vane grooves of the impeller 33. The fuel discharged into the pump chamber 22 is supplied to the outside of the fuel pump 10 through a surrounding area of the rotor 20 and the fuel passage 43.
As a result of the increase of fuel in the fuel tank in the electric connector part 50 with its opening 57 for the external connector formed upward, a part of fuel enters into the electric connector part 50. On the other hand, when a fluid level of fuel decreases as a result of the consumption of fuel, the fuel, which has entered into the electric connector part 50, moves from higher bottom faces toward lower bottom faces along the communication part bottom faces 54, 56 connected to the openings 58, 59, so as to be discharged into the outside of the electric connector part 50.
Generally, fuel remains in an electric connector part due to increase and decrease of fuel in a fuel tank. The residual fuel becomes liquid containing many involatile impure substances as a result of evaporation of its volatile matter content. The liquid including many impure substances does not easily move inside the electric connector part because of its high viscosity. Accordingly, the liquid is not easily discharged even if there is an opening for discharging the fuel, which has entered into the electric connector part, into the outside.
In the fuel pump 10 of the first embodiment of the invention, the communication part bottom faces 54, 56, whose heights become lower outward in a radial direction of the motor cover 42, are provided for the electric connector part 50. The liquid including many impure substances that has remained inside the electric connector part 50 moves toward the openings 58, 59 along the inclined surfaces of the communication part bottom faces 54, 56 by the action of gravity. Then, the liquid is discharged into the outside of the electric connector part 50 through the openings 58, 59. Accordingly, adhesion of impure substances contained in the residual liquid to the terminals 60, 61 can be prevented. As a result, development of corrosion of the terminals 60, 61, and eventually damage to the terminals 60, 61 can be prevented.

Second Embodiment

A second embodiment of the invention will be described with reference to FIGS. 5A to 7. The second embodiment is different from the first embodiment in part of a shape of a communication part bottom face that defines a communication part, which communicates with a terminal part of an electric connector part. The same numerals are used for indicating substantially the same components as the first embodiment, and their descriptions are omitted. In the second embodiment, communication part bottom faces 64, 66 defining communication parts 63, 65 include grooves respectively. Specifically, as illustrated in FIG. 7, V-shaped grooves are formed on the communication part bottom faces 64, 66 such that their recessed ridgelines 643, 663 are located in a downward direction. The communication part bottom faces 64, 66 respectively include two bottom faces, i.e., communication part center side bottom faces 641, 661 that are formed on a terminal part 51-side of the recessed ridgelines 643, 663; and communication part outer side bottom faces 642, 662 that are formed toward two side walls 501, 502 which constitute an electric connector part 50. Each two bottom faces are inclined surfaces with the corresponding recessed ridgelines 643, 663 being the lowest points. Therefore, the communication part center side bottom faces 641, 661, and the communication part outer side bottom faces 642, 662 are connected together respectively at the recessed ridgelines 643, 663.
Openings 68, 69 are connected to the V—shapes, which are constituted of the communication part center side bottom faces 641, 661 and the communication part outer side bottom faces 642, 662. Specifically, as illustrated in FIG. 6B, the V-shapes formed by the communication part center side bottom faces 641, 661 and the communication part outer side bottom faces 642, 662 coincide with part of shapes of the openings 68, 69. Thus, the shapes of the openings 68, 69 are generally pentagons respectively having one vertex at their lowest positions.
In the second embodiment, liquid that remains in the electric connector part 50 is collected at the recessed ridgelines 643, 663 along the inclined surfaces of the communication part center side bottom faces 641, 661 and the communication part outer side bottom faces 642, 662. After that, the collected liquid is discharged into the outside of the electric connector part 50 through the openings 68, 69. Since the fuel that remains inside the electric connector part 50 is gathered temporarily around the recessed ridgelines 643, 663, even if the amount of remaining liquid is small as compared with the first embodiment, the liquid is easily discharged into the outside of the electric connector part 50.
Modifications of the above embodiments will be described. Firstly, in the above first embodiment, the shape of the communication part bottom face is a planar inclined surface toward the opening. Alternatively, the shape of the communication part bottom face is not limited to this. The shape of the communication part bottom face may be a curved surface having a conical shape, a hemispherical shape, a radial shape, or the like; and a gradient ratio of its inclination may be changed within this surface.
Secondly, in the above second embodiment, a groove formed on the communication part bottom face is V-shaped at a generally central position of the communication part bottom face. However, the arrangement position of the groove, the shape of the groove, the number of grooves, and height of a recessed ridgeline of the groove are not necessarily limited to this.
Thirdly, in the above second embodiment, only the groove is formed on the communication part bottom face. Alternatively, what is formed on the communication part bottom face is not exclusive to the groove. A communication part bottom face, on which the groove is combined with the inclined surface described in the above first embodiment, may be employed.
Fourthly, in the above embodiments, the inclined surface or the groove is formed on the communication part bottom face. However, a surface, on which the inclined surface or the groove is formed, is not limited to the communication part bottom face. The inclined surface or the groove may be formed also on the terminal part bottom face, through which the terminal is disposed.
Fifthly, in the above embodiments, the height of the communication part bottom face and the height of the lower end of the opening are set to be the same. Alternatively, a positional relationship between the communication part bottom face and the opening is not necessarily limited to this. Any positional relationship may be employed as long as the height of the communication part bottom face is equal to or higher than the height of the lower end of the opening.
Sixthly, in the above embodiments, the shape of the opening is generally rectangular or generally pentagonal. However, the shape of the opening is not limited to this. The shape of the opening may be a shape that conforms with the shape of the communication part bottom face, such as a generally round shape or a generally polygon.
Lastly, in the above embodiments, the example of application of the impeller having vane grooves to the rotation member of the pump part is described. However, instead of the application of the impeller, another type of a pump, such as a Trochoid (registered trademark) pump or a gear pump, may be applied to the rotation member.
The embodiments of application of the invention to the in-tank pump disposed inside the fuel tank of the vehicle have been described above. Nevertheless, the invention is not by any means limited to such embodiments, and may be embodied in various modes without departing from the scope of the invention.
To sum up, the fuel pump 10 of the above embodiments may be described as follows.
The fuel pump 10 includes a pump part 12, a motor part 14, a motor casing 41, a motor cover 42, a terminal 60 or 61, and an electric connector part 50. The pump part 12 includes a rotation member 33 configured to suction and pressurize fuel. The motor part 14 includes a rotor 20 coupled with a rotating shaft 21 of the rotation member 33 to be capable of rotating the rotation member 33, a commutator 80 rotated together with the rotor 20 to rectify an electric current supplied to the rotor 20, and a housing 16 accommodating the rotor 20 and the commutator 80. The motor casing 41 supports one end of the rotating shaft 21 of the rotation member 33. The motor cover 42 is disposed at one end of the motor part 14 in an axial direction thereof and is fitted together with the housing 16 so as to fix the motor casing 41. The terminal 60 or 61 is disposed at an end portion of the motor cover 42 located on an opposite side from a fitted end of the motor cover 42, which is fitted with the housing 16. The terminal 60 or 61 is electrically connectable to an external connector for electricity supply. The electric connector part 50 is disposed at the end portion of the motor cover 42 located on the opposite side from the fitted end of the motor cover 42, and includes a side surface 501, 502, 503, or 504 which is slidably in contact with the external connector to determine a fitting position of the electric connector part 50 relative to the external connector, a bottom face 54 or 56; 64 or 66 from which the terminal 60 or 61 rises up, and an opening 58 or 59; 68 or 69 which is formed on the side surface 501, 502, 503, or 504 to communicate between inside and outside of the electric connector part 50. The bottom face 54 or 56; 64 or 66 is an inclined surface whose height becomes lower in a direction from generally a center of the motor cover 42 toward the opening 58 or 59; 68 or 69.
The bottom faces 54, 56 of the electric connector part 50 are inclined surfaces whose heights becomes lower from the generally center of the motor cover 42 toward the openings 58, 59. The liquid that remains inside the electric connector part 50 moves toward the openings 58, 59 having lower heights along the inclined surfaces formed on the bottom faces 54, 56 of the electric connector part 50. Then, the liquid is discharged from the openings 58, 59 into the outside of the electric connector part 50. Accordingly, corrosion of the terminals 60, 61 caused by adhesion of impure substances contained in the residual liquid can be prevented.
A gradient ratio of an inclination of the inclined surface may change within the inclined surface. Specifically, the bottom faces 54, 56 of the electric connector part 50 are not the inclined surfaces having a certain gradient ratio in the whole regions thereof. Alternatively, an arbitrary gradient ratio may be set at an arbitrary position on each of the bottom faces 54, 56 of the electric connector part 50. Consequently, by forming the inclined surfaces 54, 56 having large gradient ratios at the positions at which the liquid is more likely to remain, the residual liquid easily moves to be collected. As a result, the corrosion of the terminals 60, 61 due to attachments contained in the remaining liquid can be prevented.
The bottom face 64 or 66 may include a groove in the direction from generally the center of the motor cover 42 toward the opening 68 or 69. The groove may connect to the opening 68 or 69. By the formation of grooves on the bottom faces 64, 66 of the electric connector part 50 from the generally center of the motor cover 42 toward the openings 68, 69, the liquid that remains inside the electric connector part 50 can be collected at the lowest portions 643, 663 of the grooves. After that, the liquid collected at the lowest portions 643, 663 of the grooves is discharged into the outside through their connecting openings 68, 69. Accordingly, even if the amount of liquid remaining inside the electric connector part 50 is small, the liquid is easily removed, and corrosion of the terminals 60, 61 can be prevented.
A height of a recessed ridgeline 643 or 663 of the groove may become lower in the direction from generally the center of the motor cover 42 toward the opening 68 or 69. Consequently, the liquid gathered at the recessed ridgelines 643, 663 of the grooves moves toward the openings 68, 69 having lower heights, and is discharged into the outside of the electric connector part 50. As a result, the residual liquid can be efficiently discharged as compared with the grooves whose recessed ridgelines 643, 663 have constant heights.
Additional advantages and modifications will readily occur to those skilled in the art. The invention in its broader terms is therefore not limited to the specific details, representative apparatus, and illustrative examples shown and described.

Claims

What is claimed is:

1. A fuel pump comprising:

a pump part that includes a rotation member configured to suction and pressurize fuel;

a motor part that includes:

a rotor coupled with a rotating shaft of the rotation member to be capable of rotating the rotation member;

a commutator rotated together with the rotor to rectify an electric current supplied to the rotor; and

a housing accommodating the rotor and the commutator;

a motor casing that supports one end of the rotating shaft of the rotation member;

a motor cover that is disposed at one end of the motor part in an axial direction thereof and is fitted together with the housing so as to fix the motor casing;

a terminal that is disposed at an end portion of the motor cover located on an opposite side from a fitted end of the motor cover, which is fitted with the housing, the terminal being electrically connectable to an external connector for electricity supply; and

an electric connector part that is disposed at the end portion of the motor cover located on the opposite side from the fitted end of the motor cover and that includes:

a side surface which is slidably in contact with the external connector to determine a fitting position of the electric connector part relative to the external connector;

a bottom face from which the terminal rises up; and

an opening which is formed on the side surface to communicate between inside and outside of the electric connector part, wherein the bottom face is an inclined surface whose height becomes lower in a direction from generally a center of the motor cover toward the opening.

2. The fuel pump according to claim 1, wherein a gradient ratio of an inclination of the inclined surface changes within the inclined surface.

3. The fuel pump according to claim 1, wherein the bottom face includes a groove in the direction from generally the center of the motor cover toward the opening, the groove connecting to the opening.

4. The fuel pump according to claim 3, wherein a height of a recessed ridgeline of the groove becomes lower in the direction from generally the center of the motor cover toward the opening.

5. A fuel pump comprising:

a motor part that includes:

a housing accommodating the rotor and the commutator;

a side surface which is slidly in contact with the external connector to determine a fitting position of the electric connector part relative to the external connector;

a bottom face from which the terminal rises up; and

an opening which is formed on the side surface to communicate between inside and outside of the electric connector part, wherein the bottom face includes a groove in a direction from generally a center of the motor cover toward the opening, the groove connecting to the opening.

6. The fuel pump according to claim 5, wherein a height of a recessed ridgeline of the groove becomes lower in the direction from generally the center of the motor cover toward the opening.