Stators, fuel pump units, and methods for manufacturing fuel pump units.

Abstract

DEPCT63 Stator shaft (81) with rear connection (97), multiple teeth (99) built side to side. In the direction around the rear connection (97) and the multiple stator channels (93) that are built between Several teeth (99) are adjacent in a circumferential (theta) direction; insulation (83) covers the end surfaces of several teeth (99) in the direction The core (Z) and the inner surface of the stator's many channels (93); and the many windings (85) that are wound. Between the designated stator slots (93) through the insulator (83) is provided and the bent and protruding section (115) is provided. From both ends of the flange section (103) in a circumferential (theta) direction to the connection side. The rear (97) will be provided with insulation (83). -----------------------------------------------------------

Description

Stator, fuel pump unit, and method for manufacturing a fuel pump unit

[0001] The present invention relates to a stator, a fuel pump unit, and a method for manufacturing a fuel pump unit. This application claims priority based on Japanese Patent Application No. 2017-134782 filed in Japan on July 10, 2017, the content of which is incorporated herein by reference.

[0002] Among fuel pump units that pump fuel, which is a fluid, to an internal combustion engine with a pump, for example, among fuel pump units used in motorcycles, there are some that use an inner rotor type brushless motor to drive the pump. In an inner rotor type brushless motor, a rotor is provided so as to be rotatable with respect to a stator at the radial center of the stator. And when the pump is driven via the brushless motor, the fluid sent out from the pump passes axially between the stator and the rotor, particularly inside the brushless motor. As a stator used for such a brushless motor, for example, there is a stator disclosed in Patent Document 1.

[0003] The stator of Patent Document 1 includes an annular stator core, a plurality of slots, a plurality of flow paths, an insulator, a plurality of windings, and a resin material. The plurality of slots are provided at intervals in the circumferential direction of the end face of the stator core. The plurality of flow paths are for passing fluid along the axial direction. The plurality of flow paths are formed by connecting the plurality of slots and the central hole of the stator core. The insulator covers the inner peripheral surfaces of the plurality of slots and the adjacent slots between the end faces of the stator core. The plurality of windings are assembled between the slots via the insulator and are arranged in adjacent slots. The resin material is filled in the plurality of slots.

[0004] To fill the resin material in the plurality of slots, first, a mold is placed in the space connecting the plurality of slots and the central hole of the stator core. Next, molten resin is injected into the plurality of slots and solidified to form the resin material. Finally, the mold is removed from the stator core. As a result, the resin material is filled in the slots and the space where the mold was placed becomes the flow path.

[0005] Patent No. 4696855

[0006] However, in the stator described in Patent Document 1, if the mold is placed into the slot before the resin material is filled, the mold may come into contact with the windings in the slot, potentially damaging them. Therefore, the flow path cannot be set within the slot. Consequently, when the stator is miniaturized, a sufficient cross-sectional area of ​​the flow path cannot be secured, and the fuel cannot be passed through sufficiently.

[0007] The present invention aims to provide a stator, a fuel pump unit, and a method for manufacturing a fuel pump unit that can adequately pass fluid even when miniaturized.

[0008] According to a first aspect of the present invention, the stator comprises a stator core having a back yoke, a plurality of teeth formed in the circumferential direction of the back yoke, and a plurality of slots formed between adjacent teeth in the circumferential direction, an insulator covering the axial end faces of the plurality of teeth and the sides of the plurality of slots facing in directions other than the axial direction, and a plurality of windings wound between predetermined slots via the insulator, wherein each tooth comprises a tooth body protruding radially from the back yoke and a flange extending circumferentially from the tip of the tooth body opposite to the back yoke, and the insulator is provided with protrusions that bend and extend toward the back yoke from both circumferential ends of the flange.

[0009] In this way, the insulator has protrusions that bend and extend from both circumferential ends of the teeth flange toward the back yoke. This way, the protrusions cover the windings in the vicinity of adjacent flanges in the circumferential direction within the slots around which the windings are wound. For this reason, even in a fuel pump unit employing an inner rotor type brushless motor, where a flow path is formed by connecting the central hole of the stator core, which is formed to position the rotor radially in the center of the stator core, with multiple slots, it is possible to prevent the mold from coming into contact with the windings in the slots even if the mold is placed in the space that forms the flow path. As a result, it becomes possible to set the flow path within the slots. Therefore, even when the stator is miniaturized, it is possible to secure a sufficient cross-sectional area of ​​the flow path, allowing sufficient fluid to pass through.

[0010] According to a second aspect of the present invention, the fuel pump unit comprises a stator according to the first aspect of the present invention, a resin material filled in the slot, a rotor rotatable around the rotation axis relative to the stator, and a pump driven by the rotation of the rotor and which delivers fuel along the rotation axis, wherein a plurality of passages are formed that communicate from the radially facing side of the flange portion to the end of the protrusion portion on the back yoke side, and penetrate the resin material in the direction of the rotation axis, allowing the fuel to pass through.

[0011] This configuration prevents damage to the stator windings from the flange of the insulator, even when the flow path is set within the slot. As a result, even when the stator is miniaturized, it is possible to secure a sufficient cross-sectional area for the flow path, allowing for sufficient fluid flow.

[0012] According to a third aspect of the present invention, in the fuel pump unit according to the second aspect of the present invention, the radially outer ends of the plurality of flow paths are located at the same circumferential position as the tip of the protruding portion on the back yoke side.

[0013] This configuration makes it possible to secure a more sufficient cross-sectional area of ​​the flow path even when the stator is miniaturized. Therefore, the stator of the present invention can pass fluid more efficiently even when miniaturized.

[0014] According to a fourth aspect of the present invention, a method for manufacturing a fuel pump unit is a method for manufacturing a fuel pump unit according to a second or third aspect of the present invention, comprising: an insulator assembly step of covering the axial end faces of the plurality of teeth and the sides of the plurality of slots with an insulator and assembling the insulator to the stator core; a winding assembly step of winding the plurality of windings between predetermined slots via the insulator; a mold placement step of inserting a mold along the rotation axis between the circumferentially opposing protrusions; a resin material filling step of filling the plurality of slots with resin material after the mold placement step; and a mold removal step of removing the mold from the stator core after the resin material filling step.

[0015] As a result, during the mold placement process, when the mold is placed in the space that will become the flow path, the mold is surrounded by the protruding portion of the insulator. Therefore, there is no risk of the mold coming into contact with the windings in the slot. This makes it possible to set the flow path within the slot. Consequently, even when the stator is miniaturized, it is possible to secure a sufficient cross-sectional area of ​​the flow path. Thus, the stator manufacturing method of the present invention allows sufficient fluid to flow through the stator even when the stator is miniaturized.

[0016] The stator, fuel pump unit, and method for manufacturing the fuel pump unit of the present invention can adequately pass fluid even when miniaturized.

[0017] This is a plan view of a fuel pump unit according to an embodiment of the present invention. This is a cross-sectional view taken along line A-A in Figure 1. This is a cross-sectional view taken along line B-B in Figure 2. This is a radial cross-sectional view of the stator core of the same embodiment with the insulator assembled. This is a diagram showing the state in which the windings are assembled on the stator core from the state in Figure 4. This is a diagram showing the state in which the mold is placed on the stator core from the state in Figure 5. This is a diagram showing the state in which the resin material is filled into the stator core from the state in Figure 6. This is a diagram showing the state in which the mold has been removed from the state in Figure 7.

[0018] Next, embodiments of the present invention will be described with reference to the drawings.

[0019] Figure 1 is a plan view of the fuel pump unit 31. Figure 2 is a cross-sectional view taken along the line A-A in Figure 1. The fuel pump unit 31 is used in a fuel supply device installed, for example, in a motorcycle, to pressurize and pump fuel (fluid) to an internal combustion engine (not shown). As shown in Figures 1 and 2, the fuel pump unit 31 comprises a housing 33, a brushless motor 35, and a fuel pump 37.

[0020] The housing 33 is formed in a cylindrical shape that is long in the axial direction Z. The top and bottom surfaces of the housing 33 are open. An end cover 41 is attached to the upper side of the housing 33. The end cover 41 is made of resin. A discharge section 43 for discharging fuel is provided on the upper part of the end cover 41. The discharge section 43 is connected to the fuel supply passage described above. A check valve 45 is installed inside the discharge section 43. The check valve 45 prevents backflow of fuel discharged from the discharge section 43 into the fuel supply passage. A bearing 47 is formed at the lower part of the central part of the end cover 41.

[0021] The brushless motor 35 is located inside the housing 33, below the end cover 41. The brushless motor 35 is a so-called inner rotor type motor, comprising the stator 51 of this embodiment, a rotor 53 rotatably mounted inside the stator 51 in the radial direction R, and a shaft 55. The stator 51 is formed in an annular shape. The stator 51 is attached to the inner circumferential surface of the housing 33. The specific configuration of the stator 51 will be described later.

[0022] The rotor 53 is positioned on the inner circumference side of the stator 51. The rotor 53 is rotationally driven around the rotation axis C inside the stator 51. The rotation axis C is parallel to the axial direction Z. The rotor 53 comprises a rotor core 57 and a plurality of magnets 59. The rotor core 57 is formed in an annular shape. The rotor core 57 is formed by stacking a plurality of electromagnetic steel sheets in the axial direction Z. Through holes 61 are formed in the center of the end faces (upper and lower surfaces) of the rotor core 57, penetrating in the axial direction Z.

[0023] Multiple rotor slots 63 are formed on the outer circumferential surface of the rotor core 57 at predetermined intervals in the circumferential direction θ. Multiple magnets 59 are attached to the multiple rotor slots 63. The shaft 55 outputs the rotation of the rotor 53 as a driving force. The shaft 55 is fixed by passing through a through hole 61 in the rotor core 57. The upper end of the shaft 55 is rotatably supported by the bearing 47 described above.

[0024] The fuel pump 37 is located at the bottom of the housing 33. The fuel pump 37 is located below the brushless motor 35. The fuel pump 37 comprises a pump case 71 and an impeller 73 (rotating member). A fuel intake section 75 for drawing in fuel is provided protruding from the lower part of the pump case 71. The fuel intake section 75 is connected, for example, to a filter (not shown) of a fuel supply device. A bearing 47 is formed in the upper part of the pump case 71. The bearing 47 rotatably supports the lower end of the shaft 55. The impeller 73 is located below the bearing 47 within the pump case 71. The impeller 73 is attached to the shaft 55 and rotates in the circumferential direction θ. A pump passage 77 through which fuel passes is formed between the pump case 71 and the impeller 73.

[0025] Figure 3 is a cross-sectional view taken along the line B-B in Figure 2. The stator 51 comprises a stator core 81, an insulator 83, windings 85, and a resin material 87.

[0026] The stator core 81 is formed in an annular shape surrounding the rotor 53. A gap S is formed between the stator core 81 and the rotor 53. The gap S extends in the axial direction Z. The gap S allows fuel to pass along the axial direction Z. The stator core 81 is formed by laminating multiple electromagnetic steel sheets in the axial direction Z. A central hole 91 is provided in the central part of the end face (upper and lower surface in Figure 2) of the stator core 81.

[0027] The central hole 91 is formed extending in the axial direction Z. Multiple stator slots 93 are provided on the end face of the stator core 81. The multiple stator slots 93 are provided at predetermined intervals in the circumferential direction θ of the stator core 81. Multiple flow channels 95 are formed on the inner circumference side of the stator core 81. The multiple flow channels 95 are formed by connecting the central hole 91 of the stator core 81 and the multiple stator slots 93. The multiple flow channels 95 allow fuel to pass along the axial direction Z.

[0028] The stator core 81 has a cylindrical back yoke 97 and a plurality of teeth 99. The back yoke 97 constitutes the outer peripheral portion of the stator core 81. The back yoke 97 is formed in an annular shape. The plurality of teeth 99 are arranged on the inner circumference of the back yoke 97 at predetermined intervals in the circumferential direction θ. The plurality of teeth 99 are also formed to protrude inward in the radial direction R from the inner circumference of the back yoke 97. Each tooth 99 comprises a tooth body 101 and a flange portion 103.

[0029] The tooth body 101 is formed to protrude radially inward from the inner circumference of the back yoke 97 in the radial direction R. That is, status rods 93 are formed between adjacent tooth bodies 101 in the circumferential direction θ. The flange portion 103 is formed to be coupled to the tip of the tooth body 101. The flange portion 103 is formed to extend along both sides in the circumferential direction θ. The flange portion 103 constitutes the portion between adjacent flow channels 95, 95.

[0030] The insulator 83 is an insulating material made of resin. The insulator 83 is fitted into the stator core 81 and is installed by covering the inner circumferential surfaces (inner surfaces facing directions other than axial Z) of the multiple status rods 93 and the spaces between adjacent status rods 93, 93 on the axial Z end face of the stator core 81. The insulator 83 comprises multiple inter-slot covering portions 111 (see Figure 2), multiple slot covering portions 113, and multiple protrusions 115, 115. The inter-slot covering portions 111 cover the spaces between the status rods 93, 93. The slot covering portions 113 cover the inner circumferential surfaces of the status rods 93. The slot covering portions 113 are coupled to the inter-slot covering portions 111 in the circumferential direction θ.

[0031] The slot covering portion 113 comprises a radially outer portion 121, a circumferential one-sided portion 123, a circumferential other-sided portion 125, and radially inner portions 127, 127. The radially outer portion 121 covers the radially outer portion of the inner circumferential surface of the status rod 93. The circumferential one-sided portion 123 covers the circumferential one-sided portion of the inner circumferential surface of the status rod 93. The radially outer end of the circumferential one-sided portion 123 is connected to the radially outer portion 121. The circumferential other-sided portion 125 covers the circumferential other-sided portion of the inner circumferential surface of the status rod 93. The radially outer end of the circumferential other-sided portion 125 is connected to the radially outer portion 121. The radially inner portions 127, 127 cover the radially inner portion of the inner circumferential surface of the status rod 93. A flow path 95 is arranged between the radially inner portions 127, 127.

[0032] The protrusions 115, 115 are provided on the flow path 95 side (both ends in the circumferential direction θ of the flange portion 103) of the radially inner portions 127, 127 of the slot covering portion 113, projecting outward in the radial direction R (towards the back yoke 97). The winding 85 is wound between the status rods 93, 93 (tooth body 101) via the inter-slot covering portion 111 of the insulator 83. The winding 85 is positioned within adjacent status rods 93, 93 while wound between them. The winding 85 is positioned closer to the tooth body 101 than the protrusions 115. The winding 85 is connected to an external control device via the harness described above.

[0033] The control device controls the power supply to the winding 85 according to the rotational position of the rotor 53. As a result, the rotor 53 rotates, causing the shaft 55 to rotate, which in turn causes the impeller 73 of the fuel pump 37 to rotate.

[0034] The resin material 87 is filled into each status lot 93. Specifically, the resin material 87 is filled into the space surrounded by the insulator 83 within each status lot 93. The resin material 87 covers the windings 85, 85 adjacent in the circumferential direction θ within each status lot 93. Because the resin material 87 is filled into the space surrounded by the insulator 83 within the status lot 93, the radial outer end 141 of the flow path 95 is located at the same position in the circumferential direction θ as the tip 143 (outer end in the radial direction R) of the protrusion 115. Furthermore, the resin material 87 does not cover the inner circumferential surface of the flange portion 103 that constitutes the teeth 99. That is, with the resin material 87 filled into each status lot 93, the inner circumferential surface of the flange portion 103 is exposed.

[0035] The method for supplying fuel to the internal combustion engine in the fuel pump unit 31 configured as described above will now be explained. When the rotor 53 of the brushless motor 35 is driven to rotate, the shaft 55 rotates. When the shaft 55 rotates, the impeller 73 of the fuel pump 37 rotates. As a result, the fuel in the fuel tank is filtered through a filter (not shown) and drawn into the pump case 71 from the fuel intake section 75. The fuel drawn into the pump case 71 is pressurized in the pump passage 77 and sent to the brushless motor 35. The fuel sent to the brushless motor 35 passes through the gap S between the stator core 81 and the rotor 53 and through a plurality of passages 95, and is discharged from the discharge section 43 into a fuel supply passage (not shown). The fuel discharged into this fuel supply passage is sent to an internal combustion engine (not shown).

[0036] Next, the manufacturing method of the stator 51 of this embodiment will be explained using Figures 4 to 8. The manufacturing method of the stator 51 of this embodiment comprises the following five steps. Each step will be explained in order. (1) Insulator assembly step (2) Winding assembly step (3) Mold placement step (4) Resin material filling step (5) Mold removal step

[0037] (1) Insulator assembly process Figure 4 is a cross-sectional view along the radial R of the stator core 81 with the insulator 83 assembled. As shown in Figure 4, in the insulator assembly process, the inner circumferential surfaces of the multiple stator rods 93 of the stator core 81 and the spaces between the stator rods 93, 93 are covered with the insulator 83 and the insulator 83 is fitted into the stator core 81 to complete the assembly.

[0038] (2) Winding assembly process diagram 5 shows the state in which the winding 85 has been assembled to the stator core 81 from the state in Figure 4. As shown from Figure 4 to Figure 5, in the winding assembly process, the winding 85 is assembled by winding it between the stator rods 93, 93 via the insulator 83 and then placed in adjacent stator rods 93, 93.

[0039] (3) Diagram 6 of the mold placement process shows the state in which the mold 151 is placed on the stator core 81 from the state in Figure 5. As shown from Figure 5 to Figure 6, in the mold placement process, the mold 151 is inserted and placed along the axial direction Z into the central hole 91 of the stator core 81 and into the multiple spaces T (see Figure 5) that connect the central hole 91 and the multiple stator rods 93. The multiple spaces T become multiple flow channels 95 when the stator 51 is completed. The mold 151 comprises a mold body 153 and multiple protrusions 155. The mold body 153 is formed in a cylindrical shape. The mold body 153 is placed in the central hole 91 of the stator core 81.

[0040] Multiple projections 155 are formed to protrude from the outer circumferential surface of the mold body 153, at positions (space T) corresponding to the status rods 93 between the flange portions 103 of adjacent teeth 99 in the circumferential direction θ, so as to be inserted into these status rods 93. Furthermore, the projections 155 are formed to be inserted into the entire space between opposing projections 115 of the insulator 83 in the circumferential direction θ. In other words, the radial outer ends 155a of the multiple projections 155 of the mold 151 and the tips 143 of the projections 115 are flush in the radial direction R.

[0041] (4) Resin filling process FIG. 7 is a view showing a state in which a resin material 87 is filled in the stator core 81 from the state of FIG. 6. As shown in FIGS. 6 and 7, in the resin filling process, molten resin is injected into a plurality of stator slots 93 in a state where the protrusions 155 of the mold 151 are arranged in each space T. Subsequently, the resin is cooled and solidified to form the resin material 87. As a result, the resin material 87 is filled in the plurality of stator slots 93.

[0042] (5) Mold removal process FIG. 8 is a cross-sectional view showing a state in which the mold 151 is removed from the state of FIG. 7. As shown in FIGS. 7 and 8, in the mold removal process, the mold 151 is removed from the stator core 81 in which the resin material 87 is filled in the plurality of stator slots 93. As a result, the plurality of spaces T in which the plurality of protrusions 155 of the mold 151 were arranged become the plurality of flow paths 95.

[0043] Next, the operation and effect of the stator 51 of the present embodiment will be described.

[0044] The stator 51 of the present embodiment is a stator used for a brushless motor 35 that drives the fuel pump 37 and passes the fuel sent out from the fuel pump 37 along the axial direction Z. The stator 51 of the present embodiment includes an annular stator core 81 and a plurality of stator slots 93 provided at intervals in the circumferential direction θ of the end face of the stator core 81. Further, the stator 51 of the present embodiment includes a plurality of flow paths 95 formed by connecting the plurality of stator slots 93 and the central hole 91 of the stator core 81 and passing fuel along the axial direction Z, and an insulator 83 that covers the inner peripheral surface of the plurality of stator slots 93 and the adjacent stator slots 93, 93 between the end faces of the stator core 81. Further, the stator 51 of the present embodiment includes a plurality of windings 85 wound through the insulator 83 between adjacent stator slots 93, 93, and a resin material 87 filled in the plurality of stator slots 93. The insulator 83 is provided with protrusions 115 that protrude outward in the radial direction R on the flow path 95 side (both ends in the circumferential direction θ of the flange portion 103) of the radially inner portions 127, 127 of the slot covering portion 113 that covers the inner peripheral surface of each stator slot 93.

[0045] As a result, before filling the multiple status rods 93 with the resin material 87, the mold 151 is placed in the space T connecting the multiple status rods 93, which will form the flow path 95, and the central hole 91 of the stator core 81. At this time, the mold 151 is surrounded by the protruding portion 115 of the insulator 83. In other words, the protruding portion 115 covers the windings 85 in the vicinity of adjacent flange portions 103 in the circumferential direction θ within the status rods 93. This prevents the mold 151 from coming into contact with the windings 85 within the status rods 93, while making it possible to set up the flow path 95 within the status rods 93. Therefore, even when the stator 51 (brushless motor 35) is miniaturized, it is possible to secure a sufficient cross-sectional area of ​​the flow path 95. Thus, even when the stator 51 of this embodiment is miniaturized, it is possible to pass fuel through sufficiently.

[0046] Furthermore, in the stator 51 of this embodiment, the radially outer ends 141 of the multiple flow paths 95 are located at the same position in the circumferential direction θ as the tip 143 of the protruding portion 115. This makes it possible to secure a more sufficient cross-sectional area of ​​the flow paths 95 even when the stator 51 is miniaturized. Therefore, the stator 51 of this embodiment can pass fuel more efficiently even when miniaturized.

[0047] Further, the manufacturing method of the stator 51 of the present embodiment includes an insulator assembling step. In the insulator assembling step, the inner peripheral surfaces of a plurality of stator slots 93 of the stator core 81 and the spaces between the stator slots 93, 93 are coated with an insulator 83, and the insulator 83 is assembled to the stator core 81. Further, the manufacturing method of the stator 51 of the present embodiment includes a winding assembling step. In the winding assembling step, a winding 85 is wound between the stator slots 93, 93 via the insulator 83. Further, the manufacturing method of the stator 51 of the present embodiment includes a mold arranging step and a resin material filling step. In the mold arranging step, a mold 151 is arranged in a space T (a flow path 95 that connects a plurality of stator slots 93 and the central hole 91 of the stator core 81) between the protruding portions 115 of the insulators 83 facing each other in the circumferential direction θ. In the resin material filling step, a resin material 87 is filled into a plurality of stator slots 93 with the mold 151 arranged in the space T. Further, the manufacturing method of the stator 51 of the present embodiment includes a mold removing step. In the mold removing step, the mold 151 is removed from the stator core 81 in which the resin material 87 is filled in a plurality of stator slots 93.

[0048] Thus, in the mold arranging step, when the mold 151 is arranged in the space T, the mold 151 is surrounded by the protruding portions 115 of the insulator 83, so there is no risk that the mold 151 contacts the winding 85 in the stator slot 93. Therefore, it becomes possible to set the flow path 95 in the stator slot 93. Therefore, even when the stator 51 is miniaturized, it is possible to sufficiently secure the cross-sectional area of the flow path 95. Thus, the manufacturing method of the stator 51 of the present embodiment can sufficiently pass fluid through the stator 51 even when the stator 51 is miniaturized.

[0049] As described above, the embodiments of the present invention have been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and design changes that do not depart from the gist of the present invention are included in the present invention.

[0050] In this embodiment, the stator 51 was described in a case where the radial outer ends 141 of the multiple flow paths 95 within the stator rod 93 are positioned at the same location in the circumferential direction θ as the tip 143 of the protrusion 115. However, the embodiment is not limited to this, and the stator 51 may be formed to be located radially R inward from the tip 143 of the protrusion 115.

[0051] In this embodiment, the stator 51 was used, for example, in a fuel pump unit 31 used in a fuel supply device (not shown) installed in a motorcycle. However, it is not limited to this, and the stator 51 can be used in a variety of applications. In this embodiment, the case where the fluid is the fuel of a vehicle was described, but it is not limited to this, and it can also be applied to water, air, hydraulic fluid in a hydraulic circuit, etc.

[0052] The brushless motor 35 of this embodiment was described as a so-called inner rotor type motor comprising a stator 51, a rotor 53 rotatably mounted inside the stator 51 in the radial direction R, and a shaft 55. The stator core 81 of the stator 51 was described as having a cylindrical back yoke 97 and teeth 99 protruding inward in the radial direction R from the inner circumference of the back yoke 97. However, it is not limited to this, and the configuration of the stator 51 of this embodiment can also be adopted for a so-called outer rotor type brushless motor in which the rotor is arranged on the outer circumference of the stator. In other words, the configuration of the stator 51 of this embodiment can also be adopted for a stator having teeth that protrude radially outward from the radially outer side of the back yoke.

[0053] The stator, fuel pump unit, and method for manufacturing the fuel pump unit described above can adequately pass fluid even when miniaturized.

[0054] 31...Fuel pump unit, 35...Brushless motor, 37...Fuel pump (pump), 51...Stator, 53...Rotor, 81...Stator core, 83...Insulator, 85...Winding, 87...Resin material, 91...Central hole, 93...Stator rod (slot), 95...Flow path, 97...Back yoke, 99...Teeth, 101...Teeth body, 103...Flange, 113...Slot covering, 115...Protrusion, 127...Radial inner part, 141...Radial outer end, 143...Tip, C...Rotation axis, Z...Axial direction (Rotation axis direction), R...Radial direction, θ...Circumferential direction

Claims

DEPCT631. The stator consists of: the stator core with a rear junction; multiple segments constructed side-to-side in the circumferential direction of the rear junction and multiple channels constructed between adjacent segments in the circumferential direction; insulation covering the end surfaces of the segments in the axial direction and the side surfaces of the channels facing away from the axial direction; and multiple windings wound between defined channels through the insulation, where each of the segments has segments extending radially from the rear junction and flanges extending in the circumferential direction from the ends of the segments opposite the rear junction, and where bent and protruding segments from both ends of the flanges in the circumferential direction towards the rear junction are provided in the insulation.2.The fuel pump unit comprises: a stator according to claim 1; resin material filled into the cavities; a rotor that can rotate axially relative to the stator; and a pump driven by the rotor's rotation and transferring fuel axially, where multiple flow paths are created extending radially from the side surface of the flange to the end of the protrusion on the rear connection side and penetrating axially through the resin material to allow fuel to pass through.

3. The fuel pump unit according to claim 2 is of the type where the outer radial ends of the multiple flow paths are positioned at the same position of the end of the protrusion on the rear connection side in the axial direction.4.Methods for manufacturing fuel pump units according to claim 2 or claim 3, assembly methods include: the insulation assembly process in which the end surfaces of several axial protrusions and the side surfaces of several slots are covered with insulation and the insulation is assembled onto the stator core; the winding assembly process in which several windings are wound between defined slots through insulation; the die mounting process in which the die is inserted between projecting sections facing each other in the axial direction; the resin filling process in which resin is filled into several slots after the die mounting process; and the die removal process in which the die is removed from the stator core after the resin filling process.