JP6500455B2 - Fuel pump - Google Patents

Description

  The present invention relates to a fuel pump that sequentially sucks and discharges fuel into pump chambers.

  2. Description of the Related Art Conventionally, a fuel pump is known which discharges fuel after sequentially drawing fuel into each pump chamber. The fuel pump disclosed in Patent Document 1 includes an outer gear having a plurality of inner teeth, an inner gear having a plurality of outer teeth and eccentrically meshing with the outer gear in an eccentric direction, and a pump housing rotatably accommodating both gears. And an electric motor having a rotating shaft that is rotationally driven. The outer gear and the inner gear rotate while expanding and contracting the volume of the plurality of pump chambers formed between the both gears, so that the fuel is sequentially sucked into the respective pump chambers and then discharged.

  And, a coupling connects the rotating shaft and the inner gear. In this coupling, the radially protruding protrusion engages with the inner wall groove of the inner gear.

JP-A-6-123288

  However, in the fuel pump of Patent Document 1, when the rotation shaft is deviated and the coupling is inclined, the inner gear is pushed by the force in the axial direction by the coupling, so that it does not rotate smoothly and the pump efficiency is reduced. There was a problem that it decreased.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide a fuel pump with high pump efficiency.

One disclosed invention is an outer gear (30) having a plurality of internal teeth (32a);
An inner gear (20) having a plurality of external teeth (24a) and being eccentrically engaged with an outer gear in an eccentric direction (De);
A pump housing (10) rotatably accommodating the outer gear and the inner gear;
An electric motor (4) having a rotating shaft (4a) that is rotationally driven;
A joint member (60) relaying the rotation shaft to the inner gear;
The outer gear and the inner gear are sequentially sucked and discharged into each pump chamber by rotating while expanding and contracting the volume of the pump chamber (40) formed in a plurality between the both gears,
The inner gear has an insertion hole (27) recessed along the axial direction
The joint member is
A main body (62) fitted to the rotary shaft;
A foot (64) which extends along the axial direction from the main body and is inserted with a gap in the insertion hole;
Possess toward the foot to the rotation progresses side of the inner gear protrudes protrusion width in Hodojiku direction toward the apex portion (66a) is narrowed and (66),
The projecting portion and the body portion, characterized that you have separated.
Another disclosed invention relates to an outer gear (30) having a plurality of internal teeth (32a),
An inner gear (20) having a plurality of external teeth (24a) and being eccentrically engaged with an outer gear in an eccentric direction (De);
A pump housing (10) rotatably accommodating the outer gear and the inner gear;
An electric motor (4) having a rotating shaft (4a) that is rotationally driven;
A joint member (60) relaying the rotation shaft to the inner gear;
The outer gear and the inner gear are sequentially sucked and discharged into each pump chamber by rotating while expanding and contracting the volume of the pump chamber (40) formed in a plurality between the both gears,
The inner gear has an insertion hole (27) recessed along the axial direction
The joint member is
A main body (62) fitted to the rotary shaft;
A foot (64) which extends along the axial direction from the main body and is inserted with a gap in the insertion hole;
And a projecting portion (66) which protrudes from the foot toward the rotation advancing side of the inner gear and whose width in the axial direction becomes narrower toward the apex (66a),
Multiple insertion holes are provided,
A plurality of feet and protrusions are provided corresponding to the insertion holes,
The plurality of foot portions are characterized in that they are circumferentially aligned with one another so as to avoid opposite positions across the inner center line (Cig).

  According to such an invention, when the rotary shaft of the electric motor is rotationally driven, the joint member having the main body portion fitted to the rotary shaft rotates with the rotary shaft. Then, since the foot extending from the main body in the axial direction is inserted into the insertion hole of the inner gear with a gap, the inner gear can be rotated. Here, since the protrusion protrudes from the foot toward the rotational advancing side of the inner gear, the inner gear rotates while the protrusion contacts the inner peripheral wall of the inner gear. According to this, it is possible to prevent the foot from coming into contact with the edge portion of the insertion hole even when the rotation axis is displaced and the joint member is inclined. Therefore, it is possible to prevent the inner gear from being pushed by an axial force and to rotate smoothly, so it is possible to provide a fuel pump with high pump efficiency.

  Note that the reference numerals in parentheses are for illustrating the corresponding configuration in the embodiments described later to facilitate understanding of the description content, and are not intended to limit the content of the invention.

It is a partial section front view showing a fuel pump in one embodiment. It is the II-II sectional view taken on the line of FIG. It is the III-III sectional view taken on the line of FIG. It is the IV-IV sectional view taken on the line of FIG. It is the figure which looked at the inner gear in one Embodiment from the arrangement | positioning space side. It is a sectional view showing a joint member in one embodiment. It is the arrow line view seen from the VII direction of FIG. It is a figure for demonstrating the contact with a joint member and an inner gear. It is a figure for demonstrating the contact with a joint member and an inner gear, Comprising: The case where a joint member inclines is shown. It is a figure corresponding to FIG. 8 in the modification 1. FIG. It is a figure corresponding to FIG. 8 in the modification 3. FIG. It is a figure corresponding to FIG. 8 in the modification 6. FIG.

  Hereinafter, an embodiment of the present invention will be described based on the drawings.

  As shown in FIG. 1, a fuel pump 100 according to an embodiment of the present invention is a positive displacement trochoid pump mounted on a vehicle. The fuel pump 100 includes a pump main body 3 housed in a cylindrical pump body 2 and a side cover 5 protruding outward from an end opposite to the pump main body 3 with the electric motor 4 axially sandwiched. . Here, the side cover 5 includes an electrical connector 5 a for energizing the electric motor 4 and a discharge port 5 b for discharging the fuel. In the fuel pump 100, the rotation shaft 4a of the electric motor 4 is rotationally driven by energization from the external circuit through the electrical connector 5a. As a result, the fuel sucked and pressurized by the pump main body 3 using the driving force of the rotary shaft 4a of the electric motor 4 is discharged from the discharge port 5b. The fuel pump 100 discharges light oil having a viscosity higher than that of gasoline as fuel.

  In the present embodiment, an inner rotor type brushless motor in which magnets are arranged in four poles is adopted as the electric motor 4. At the time of start-up, the rotation shaft 4a of the electric motor 4 is reversely rotated with respect to the normal rotation direction (that is, it rotates in the opposite direction to the rotation direction Rig described later).

  In addition, below, the rotation advancing side shows the side used as the positive direction of the rotation direction Rig. The reverse rotation side indicates the side that is the negative direction of the rotation direction Rig.

  Hereinafter, the pump body 3 will be described in detail. The pump body 3 includes a pump housing 10, an inner gear 20, an outer gear 30, and a joint member 60. Here, the pump housing 10 is formed by overlapping the pump cover 12 and the pump casing 16.

  The pump cover 12 is formed in a disk shape of metal. The pump cover 12 protrudes outward from the end of the pump body 2 opposite to the side cover 5 with the electric motor 4 interposed therebetween in the axial direction.

  The pump cover 12 shown in FIGS. 1 and 2 forms a cylindrical hole-like suction port 12 a and a circular arc groove-like suction passage 13 in order to suck fuel from the outside. The suction port 12 a penetrates a specific opening Ss of the pump cover 12 eccentric to the inner center line Cig of the inner gear 20 along the axial direction of the cover 12. The suction passage 13 is opened to the pump casing 16 side of the pump cover 12. As shown in FIG. 2, the inner peripheral portion 13 a of the suction passage 13 extends along the rotation direction Rig of the inner gear 20 (see also FIG. 4) to a length less than a half circumference. The outer peripheral portion 13 b of the suction passage 13 extends along the rotation direction Rog of the outer gear 30 to a length less than a half circumference.

  Here, the suction passage 13 is widened as it goes from the start end 13 c to the end 13 d in the rotational direction Rig, Rog. The suction passage 13 communicates with the suction port 12a by opening the suction port 12a at the opening Ss of the groove bottom 13e. In particular, as shown in FIG. 2, the width of the suction passage 13 is set to be smaller than the diameter of the suction port 12 a in the entire opening area Ss where the suction port 12 a is opened.

  In addition, the pump cover 12 forms a recessed hole-shaped arrangement space 58 in which the main body portion 62 of the joint member 60 is rotatably disposed at a position facing the inner gear 20 on the inner center line Cig.

  The pump casing 16 shown in FIGS. 1, 3 and 4 is formed of metal and has a bottomed cylindrical shape. The opening 16 a of the pump casing 16 is covered by the pump cover 12 so that the entire circumference is sealed. The inner peripheral portion 13a of the pump casing 16 is formed in a cylindrical hole shape eccentric to the inner center line Cig of the inner gear 20 as particularly shown in FIGS.

  The pump casing 16 forms a discharge passage 17 in the form of an arc hole in order to discharge the fuel from the discharge port 5 b through the fuel passage 6 between the pump body 2 and the electric motor 4. The discharge passage 17 penetrates the recessed bottom portion 16 c of the pump casing 16 along the axial direction. In particular, as shown in FIG. 3, the inner circumferential portion 17 a of the discharge passage 17 extends along the rotation direction Rig of the inner gear 20 to a length less than a half circumference. The outer peripheral portion 17 b of the discharge passage 17 extends along the rotation direction Rog of the outer gear 30 to a length less than a half circumference. Here, the discharge passage 17 is narrowed as it goes from the start end 17 c to the end 17 d in the rotational direction Rig, Rog.

  The pump casing 16 also has a reinforcing rib 16 d in the discharge passage 17. The reinforcing rib 16 d is integrally formed with the pump casing 16 and is a rib that reinforces the pump casing 16 by straddling the discharge passage 17 in a direction intersecting with the rotation direction Rig of the inner gear 20.

  As shown in FIG. 3, in a portion of the concave bottom portion 16c of the pump casing 16 facing the suction passage 13 across the pump chamber 40 (described in detail later) between the gears 20 and 30, the passage 13 is A suction groove 18 shaped like a circular arc groove is formed corresponding to the shape projected in the direction. As a result, in the pump casing 16, the discharge passage 17 and the suction groove 18 are provided so that their contours are substantially in line symmetry. On the other hand, as shown in FIG. 2 in particular, a portion of the pump cover 12 facing the discharge passage 17 across the pump chamber 40 corresponds to the shape of the passage 17 projected in the axial direction, The discharge groove 14 is formed. As a result, in the pump cover 12, the suction passage 13 and the discharge groove 14 are provided so that their contours are substantially in line symmetry.

  As shown in FIG. 1, a radial bearing 50 is fitted and fixed on the inner center line Cig of the concave bottom portion 16 c of the pump casing 16 in order to radially support the rotary shaft 4 a of the electric motor 4. . On the other hand, a thrust bearing 52 is fitted and fixed on the inner center line Cig of the pump cover 12 in order to axially support the rotary shaft 4a.

  As shown in FIGS. 1 and 4, the concave bottom portion 16 c and the inner circumferential portion 16 b of the pump casing 16 define a housing space 56 housing the inner gear 20 and the outer gear 30 in cooperation with the pump cover 12. The inner gear 20 and the outer gear 30 are so-called trochoidal gears in which the tooth profile curve of each tooth is trochoid curved.

  The inner gear 20 shown in FIGS. 1, 4 and 5 is disposed eccentrically in the housing space 56 by making the inner center line Cig common to the rotation axis 4 a. The inner peripheral portion 22 of the inner gear 20 is radially supported by the radial bearing 50, and the sliding surfaces 25 on both sides in the axial direction are supported by the concave bottom portion 16 c of the pump casing 16 and the pump cover 12.

  In addition, the inner gear 20 has an insertion hole 27 recessed in the axial direction at a position facing the placement space 58. In the present embodiment, a plurality of insertion holes 27 are provided in the circumferential direction along the rotation direction Rig, and each insertion hole 27 penetrates to the concave bottom portion 16 c side. By inserting the corresponding legs 64 of the joint member 60 into the insertion holes 27, the driving force of the rotation shaft 4 a is transmitted to the inner gear 20 via the joint member 60. In this way, the inner gear 20 rotates in the fixed rotation direction Rig around the inner center line Cig while sliding the sliding surface 25 on the concave bottom portion 16c and the pump cover 12 according to the rotation of the rotating shaft 4a by the electric motor 4. It is possible.

  The inner gear 20 has a plurality of external teeth 24 a arranged at equal intervals in the rotation direction Rig at the outer peripheral portion 24. Each external tooth 24a can be axially opposed to each passage 13, 17 and each groove 14, 18 according to the rotation of the inner gear 20, thereby suppressing sticking to the concave bottom portion 16c and the pump cover 12. ing.

  Further, in each of the inner peripheral walls 27a of the insertion holes 27 of the present embodiment, planar inner surface portions along the radial direction of the inner gear 20 in the inner peripheral wall on the rotation advancing side and the inner peripheral wall on the rotation reverse side. It has 27b and 27c.

  The outer gear 30 shown in FIGS. 1 and 4 is disposed coaxially in the housing space 56 by being eccentric to the inner center line Cig of the inner gear 20. Thus, with respect to the outer gear 30, the inner gear 20 is eccentric in the eccentric direction De as one radial direction. The outer peripheral portion 34 of the outer gear 30 is radially supported by the inner peripheral portion 16 b of the pump casing 16, and is axially supported by the concave bottom portion 16 c of the pump casing 16 and the pump cover 12. The outer gear 30 is rotatable in a fixed rotational direction Rog around the outer center line Cog eccentric to the inner center line Cig by these bearings.

  The outer gear 30 has a plurality of inner teeth 32 a arranged in the inner circumferential portion 32 at equal intervals in the rotational direction Rog. Here, the number of the internal teeth 32 a in the outer gear 30 is set to be one more than the number of the external teeth 24 a in the inner gear 20. Each internal tooth 32a can be axially opposed to each passage 13, 17 and each groove 14, 18 according to the rotation of the outer gear 30, thereby suppressing sticking to the concave bottom portion 16c and the pump cover 12. ing.

  The inner gear 20 meshes with the outer gear 30 due to relative eccentricity in the eccentric direction De. Thus, a plurality of pump chambers 40 are formed in series between the gears 20 and 30 in the accommodation space 56. The volume of such a pump chamber 40 is expanded and contracted as the outer gear 30 and the inner gear 20 rotate.

  As the gears 20 and 30 rotate, the volume of the pump chamber 40, which is oppositely in communication with the suction passage 13 and the suction groove 18, increases. As a result, fuel is drawn into the pump chamber 40 through the suction passage 13 from the suction port 12a. At this time, the amount of fuel drawn through the suction passage 13 is an amount of expansion of the volume of the pump chamber 40 because the suction passage 13 is wider as it goes from the start end 13c to the end 13d (see also FIG. 2). According to

  As the gears 20 and 30 rotate, the volume of the pump chamber 40 in communication with the discharge passage 17 and the discharge groove 14 is reduced. As a result, fuel is discharged from the pump chamber 40 through the discharge passage 17 into the fuel passage 6 simultaneously with the suction function. At this time, the amount of fuel discharged through the discharge passage 17 is reduced as the volume of the pump chamber 40 is reduced because the discharge passage 17 is narrowed as it goes from the start end portion 13c to the end portion 13d (see also FIG. 3). It corresponds to the amount.

  The joint member 60 is formed of, for example, a synthetic resin such as polyphenylene sulfide resin as shown in FIGS. 1, 2, 4, 6 and 7, and relays the rotation shaft 4 a to the inner gear 20. The joint member 60 has a main body 62, a foot 64, a protrusion 66, and a reverse protrusion 68.

  The main body 62 is disposed in the arrangement space 58 formed in the pump cover 12 and is formed in an annular shape with a fitting hole 62a open at the center, and the rotary shaft 4a is inserted through the fitting hole 62a. Thus, the rotary shaft 4a is fitted and fixed.

  A plurality of foot portions 64 are provided corresponding to the number of insertion holes 27 of the inner gear 20. Specifically, the foot portion 64 is provided as a prime number of five, avoiding the number of poles of the magnet of the electric motor 4. Such foot portions 64 are provided side by side in the circumferential direction. Each foot 64 extends from the main body 62 in the axial direction, and is inserted into the corresponding insertion hole 27 with a gap. The tip end 64 a of each foot portion 64 extends to the electric motor 4 side of the center of gravity of the inner gear 20 in the axial direction with respect to each insertion hole 27 penetrating the inner gear 20 in the axial direction. It extends so as not to reach to.

  A plurality of protrusions 66 are provided corresponding to the number of each insertion hole 27 and each foot 64. Each protrusion 66 protrudes from the corresponding foot 64 toward the rotation direction side of the inner gear 20. Each protrusion 66 of the present embodiment protrudes from the main body 62 side with respect to the tip 64 a so as to avoid the tip 64 a of each foot 64.

  Each projecting portion 66 is formed such that the width in the axial direction becomes narrower toward the vertex 66 a. Specifically, the protrusion 66 protrudes in a curved convex shape having a curvature in the axial direction, and more specifically, as shown in FIG. 7 in particular, a partial cylindrical surface having a generatrix Lg along the radial direction ing. Each apex 66a is located in the insertion hole 27 with the tip 64a of the corresponding foot 64 (see also FIG. 8).

  Similarly to the protrusions 66, a plurality of the reverse protrusions 68 are provided corresponding to the number of the insertion holes 27 and the number of the feet 64. Each reverse protrusion 68 protrudes from the corresponding foot 64 toward the reverse rotation side of the inner gear 20. Each reverse projecting portion 68 projects in the same shape as the projecting portion 66, and has a substantially line symmetrical shape with the projecting portion 66 across the bisector of the foot portion 64.

  Due to such a shape of the joint member 60, the proximal end portion 64b of each foot 64 with respect to the main body 62 and the corresponding protrusion 66, and with respect to the main body 62 and the corresponding reverse protrusion 68, It has a narrow shape.

  When the rotary shaft 4a is driven to rotate, although depending on the displacement state of the rotary shaft 4a, for example, two or three of the five projecting portions 66 simultaneously project as shown in FIG. It contacts with the flat portion 27 b of the inner circumferential wall 27 a on the rotational advancing side with respect to the surface 66. Further, when the joint member 60 is inclined with respect to the inner gear 20 as shown in FIG. 9 by receiving vibration etc. from the outside (for example, vehicle vibration) and the rotational shaft 4a is shifted with respect to the inner center line Cig. Also in the projecting portion 66, a curved convex portion slightly shifted from the apex 66a contacts the flat portion 27b.

  In the joint member 60 formed of a resin material, there is a concern that the protrusion 66 may be worn by contact. However, in the present embodiment, when the joint member 60 is inclined, the curved convex convex portion deviated from the apex 66a according to the angle contacts the flat portion 27b, thereby avoiding significant abrasion of only a specific portion. doing. In addition, in the joint member 60 formed of a resin material, thermal expansion, swelling by fuel, or deformation of the foot due to the contact may occur. However, even if such deformation occurs a little, any part of the curved convex portion of the protrusion 66 comes in contact with the flat portion 27b.

  Thus, the driving force of the rotation shaft 4a is relayed to the joint member 60 and transmitted to the inner gear 20, and the inner gear 20 is rotated in the rotation direction Rig. Then, the fuel is sequentially drawn into the respective pump chambers 40 by the fuel pump 100 and discharged from the respective pump chambers 40.

(Action effect)
The effects and advantages of the present embodiment described above will be described below.

  According to the present embodiment, when the rotary shaft 4a of the electric motor 4 is rotationally driven, the joint member 60 having the main body portion 62 fitted to the rotary shaft 4a rotates with the rotary shaft 4a. Then, since the foot portion 64 extending in the axial direction from the main body portion 62 is inserted into the insertion hole 27 of the inner gear 20 with a gap, the inner gear 20 becomes rotatable. Here, since the protruding portion 66 protrudes from the foot portion 64 toward the rotational advancing side of the inner gear 20, the inner gear 20 is rotated while the protruding portion 66 is in contact with the inner peripheral wall 27a of the inner gear 20. According to this, it is possible to prevent the foot 64 from coming into contact with the edge portion of the insertion hole 27 even when the rotation shaft 4a is displaced and the joint member 60 is inclined. Therefore, it is possible to prevent the inner gear 20 from being pushed in the axial direction and to rotate smoothly, and it is possible to provide the fuel pump 100 with high pump efficiency.

  Further, according to the present embodiment, the protrusion 66 protrudes in a curved convex shape having a curvature in the axial direction. In the case where the rotational shaft 4a is displaced and the joint member 60 is inclined, the curved convex protrusion 66 can contact the insertion hole 27 along the axial direction. For this reason, it is possible to more reliably prevent the inner gear 20 from being pushed by receiving the force in the axial direction, and it is possible to smoothly rotate, so that the pump efficiency can be enhanced.

  Further, according to the present embodiment, the insertion hole 27 has the flat portion 27b along the radial direction on the inner peripheral wall 27a on the rotation advancing side with respect to the protrusion 66, and the protrusion 66 extends along the radial direction. It protrudes in the shape of a partial cylindrical surface having a generating line Lg. Since the driving force of the rotating shaft 4a is efficiently transmitted in the rotation direction Rig by making such a protruding portion 66 line contact with the flat portion 27b, the inner gear 20 can be smoothly rotated and the pump efficiency can be enhanced.

  Further, according to the present embodiment, the protruding portion 66 protrudes from the main body portion 62 side more than the tip end 64 a of the foot portion 64. Therefore, when manufacturing the fuel pump 100, the tip 64 a of the foot 64 can be easily inserted into the insertion hole 27, and the tip 64 a of the foot 64 functions as a guide. It also becomes easy to insert. Therefore, the joint member 60 can be easily assembled to the inner gear 20.

  Further, according to the present embodiment, a plurality of insertion holes 27 are provided, and a plurality of foot portions 64 and a plurality of protrusions 66 are provided corresponding to the insertion holes 27. According to this, when the rotational shaft 4a is displaced, and the joint member 60 is inclined, the projection 66 can be brought into contact with the inner peripheral wall 27a of the insertion hole 27 corresponding to various inclinations, so that the pump Efficiency can be improved.

  Further, according to the present embodiment, the joint member 60 has the reverse projecting portion 68 projecting in the same shape as the projecting portion 66 from the foot 64 toward the reverse rotation side of the inner gear 20. According to this, even when the rotary shaft 4a rotates in the reverse rotation direction, for example, when the electric motor 4 is started, the edges of the foot 64 and the insertion hole 27 contact and the inner gear 20 receives an axial force. It is possible to prevent the inner gear 20 from rotating smoothly.

(Other embodiments)
As mentioned above, although one Embodiment of this invention was described, this invention is not limited and interpreted to the said embodiment, It is applied to various embodiment in the range which does not deviate from the summary of this invention. it can.

  Specifically, as a first modification, as shown in FIG. 10, the protrusion 66 may protrude from the tip end 64 a of the foot 64 to the rotation advancing side of the inner gear 20.

  As a second modification, the protruding portion 66 may be, for example, spherically protruding as a curved convex shape having a curvature in the axial direction.

  In the third modification, as shown in FIG. 11, the projecting portion 66 whose width in the axial direction becomes narrower toward the apex 66a has an inclined surface 67 inclined with respect to the axial direction, and the apex 66a has a pointed shape Can be adopted.

  As a fourth modification, the projecting portion 66 may protrude from one or more of the plurality of foot portions 64, not from all the foot portions 64.

  As a fifth modification, the joint member 60 may not have the reverse projection 68.

  As a sixth modification, the insertion hole 27 may have a tapered surface 28 at the edge portion, as shown in FIG. In the joint member having the projecting portion 66, when the rotational shaft 4a is shifted, and the joint member 60 is inclined, the foot 64 also has the tapered surface 28 of the insertion hole 27 for such an insertion hole 27. Contact with the included edge portion can be avoided.

  As a seventh modification, the insertion hole 27 may not have the flat portion 27 b along the radial direction on the inner peripheral wall 27 a on the rotation advancing side with respect to the protrusion 66. For example, the insertion hole 27 may have a circular, elliptical, or other cross-sectional shape.

  As the eighth modification, the insertion hole 27 may not penetrate to the concave bottom portion 16 c side as long as the insertion hole 27 is concave in the axial direction.

  As a modification 9, the fuel pump 100 may suck and discharge gasoline other than light oil or liquid fuel based thereon as fuel.

  100 fuel pump, 4 electric motor, 4a rotary shaft, 10 pump housing, 20 inner gear, 24a external gear, 27 insertion hole, 27a inner peripheral wall, 27b flat part, 30 outer gear, 32a internal gear, 40 pump chamber, 60 joint members, 62 body, 64 feet, 64a tip, 66 protrusions, 66a apex, 68 reverse protrusions, De eccentric direction, Lg bus bar

Claims (7)

An outer gear (30) having a plurality of internal teeth (32a);
An inner gear (20) having a plurality of external teeth (24a), and eccentrically meshing with the outer gear in an eccentric direction (De);
A pump housing (10) rotatably accommodating the outer gear and the inner gear;
An electric motor (4) having a rotating shaft (4a) that is rotationally driven;
A joint member (60) relaying the rotation shaft to the inner gear;
The outer gear and the inner gear are rotated while expanding and contracting the volume of the pump chamber (40) formed between the both gears, whereby fuel is sequentially sucked into each of the pump chambers and then discharged.
The inner gear has an insertion hole (27) recessed in the axial direction,
The joint member is
A main body (62) fitted to the rotary shaft;
A foot (64) which extends along the axial direction from the main body and is inserted with a gap in the insertion hole;
They possess protrude from the foot toward the rotation progresses side of said inner gear, protrusion width in Hodojiku direction toward the apex portion (66a) is narrowed and (66),
Wherein the projecting portion and the body portion, the fuel pump characterized that you have separated. A plurality of the insertion holes are provided,
The fuel pump according to claim 1, wherein a plurality of the foot portion and the projection portion are provided corresponding to the insertion hole. An outer gear (30) having a plurality of internal teeth (32a);
An inner gear (20) having a plurality of external teeth (24a), and eccentrically meshing with the outer gear in an eccentric direction (De);
A pump housing (10) rotatably accommodating the outer gear and the inner gear;
An electric motor (4) having a rotating shaft (4a) that is rotationally driven;
A joint member (60) relaying the rotation shaft to the inner gear;
The outer gear and the inner gear are rotated while expanding and contracting the volume of the pump chamber (40) formed between the both gears, whereby fuel is sequentially sucked into each of the pump chambers and then discharged.
The inner gear has an insertion hole (27) recessed in the axial direction,
The joint member is
A main body (62) fitted to the rotary shaft;
A foot (64) which extends along the axial direction from the main body and is inserted with a gap in the insertion hole;
They possess protrude from the foot toward the rotation progresses side of said inner gear, protrusion width in Hodojiku direction toward the apex portion (66a) is narrowed and (66),
A plurality of the insertion holes are provided,
A plurality of the foot and the projection are provided corresponding to the insertion hole,
The plurality of the foot, so as to avoid the opposite position across the inner center line (Cig), a fuel pump, wherein Rukoto lined in the circumferential direction. The fuel pump according to any one of claims 1 to 3, wherein the protrusion protrudes in a curved convex shape having a curvature in an axial direction. The insertion hole has a flat portion (27b) along a radial direction on an inner peripheral wall (27a) on the rotational advancing side with respect to the protrusion.
The fuel pump according to any one of claims 1 to 4, wherein the projecting portion protrudes in a partial cylindrical shape having a generatrix (Lg) along a radial direction. The fuel pump according to any one of claims 1 to 5 , wherein the projecting portion projects from the main body side with respect to a tip end (64a) of the foot portion. The joint member according to any one of claims 1 to 6 , wherein the joint member has a reverse projecting portion (68) projecting in the same shape as the projecting portion toward the reverse rotation side of the inner gear from the foot portion. The fuel pump according to claim 1.

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