Motor unit and liquid supply device

Abstract

The motor unit (3) of the motor unit included in the liquid supply device (1) has an upper case (43) and a yoke (5). The first positioning protrusions (35) of the yoke (5) are arranged at substantially equal intervals in the circumferential direction, and the second positioning protrusions (36) are arranged at substantially equal intervals in the circumferential direction. The first positioning protrusions (35), the second positioning protrusions (36), and the first positioning convex portion (13) of the outer shell (2) are arranged at positions that do not overlap each other in the circumferential, radial, and axial directions.

Description

Technical Field

[0001] The present invention relates to a motor unit and a liquid supply device. Background Art

[0002] For example, a liquid supply device for vehicles such as motorcycles and four-wheel vehicles includes a fuel pump that sucks fuel from a fuel tank and pumps it toward an engine. The fuel pump includes a pump section and a motor section that drives the pump section.

[0003] For example, a non-positive displacement pump having an impeller is used as the pump section. Such a pump section includes an impeller and a pump casing formed to cover the entire impeller.

[0004] For example, a brushed motor is used as the motor section. Such a motor section includes a cylindrical yoke, a permanent magnet fixed to the inner peripheral surface of the yoke, an armature rotatably supported within the yoke, and a brush for supplying power to the armature. The yoke is formed, for example, by bending a single metal plate into a cylindrical shape. The brush biases the commutator of the armature via a spring or the like and is electrically connected to an external power source.

[0005] After aligning and overlapping the pump casing and the yoke coaxially, such a pump section and motor section are housed within a cylindrical housing. By caulking the axial ends of the housing, the pump section and the motor section are integrated.

[0006] According to such a configuration, when the impeller is rotationally driven by the motor section, fuel in the fuel tank is sucked into the pump section. Thereafter, the fuel passes through the motor section and is discharged from a discharge pipe provided on the fuel pump and is pumped to the engine.

[0007] Prior Art Documents

[0008] Patent Documents

[0009] Patent Document 1: Japanese Patent Application Laid-Open No. 2010-183798 Summary of the Invention

[0010] Problems to be Solved by the Invention

[0011] In addition, in order to arrange the pump section and the motor section coaxially, the yoke and the pump casing may be fitted together. In addition, in order to perform circumferential positioning of the yoke and the pump casing, convex and concave portions for engaging are sometimes provided on the yoke and the pump casing. In addition, for example, in the case of using a progressive stamping processing device or the like to improve the productivity of the yoke, protrusions or the like for positioning with respect to the processing device are sometimes provided on the yoke.

[0012] When simply adopting these structures, the biasing force of the brush against the commutator and the fixing strength of the pump section and the motor section with respect to the housing may become unstable. In addition, the performance of the motor section may deteriorate.

[0013] Accordingly, one object of the present invention is to provide a motor unit and a liquid supply device that can stabilize the fixing strength relative to the housing while positioning each part and can improve motor performance.

[0014] Solution to the problem

[0015] The motor unit according to the first aspect of the present invention includes:

[0016] A housing, which is cylindrical;

[0017] A bracket, which is circular plate-shaped and is fitted on the inner peripheral surface of the housing; and

[0018] A motor part, which is disposed inside the housing and is coaxial with the bracket,

[0019] The motor part has:

[0020] A yoke, which is fitted on the inner peripheral surface of the housing and is formed of a single metal plate bent into a cylindrical shape; and

[0021] A plurality of permanent magnets, which are disposed on the inner peripheral surface of the yoke,

[0022] An end face of the bracket in the axial direction contacts an end portion of the yoke on the bracket side,

[0023] The housing has:

[0024] A first positioning portion, which is formed at a position corresponding to the bracket and is used for positioning the housing and the bracket,

[0025] The yoke has:

[0026] A plurality of first positioning protrusions, which are provided to protrude from the end portion toward the bracket side at a position avoiding the butt joint surface of the metal plate and are used for positioning with the bracket; and

[0027] A plurality of second positioning protrusions, which are provided to protrude from the end portion toward the bracket side at a position avoiding the butt joint surface and are used for positioning relative to the device that conveys the yoke,

[0028] The bracket has:

[0029] A second positioning portion, which can be engaged with the first positioning portion; and

[0030] A plurality of positioning recesses, into which the plurality of first positioning protrusions are respectively inserted,

[0031] One of the second positioning portion and the plurality of positioning recesses is separately disposed on both sides with the rotation axis of the motor part as the center,

[0032] When the number of the first positioning protrusions is set to N1, the circumferential angle centered on the rotation axis between adjacent first positioning protrusions is 360° / N1 - 30° or more and 360° / N1 + 30° or less.

[0033] When the number of the second positioning protrusions is set to N2, the circumferential angle between adjacent second positioning protrusions is 360° / N2 - 30° or more and 360° / N2 + 30° or less.

[0034] The first positioning protrusion, the second positioning protrusion, and the first positioning portion are arranged at positions that do not overlap with each other in the circumferential direction, radial direction, and axial direction.

[0035] With such a configuration, the positions of the first positioning protrusion and the second positioning protrusion relative to the yoke can be optimized, and the positions of the second positioning portion and the positioning recess relative to the bracket can be optimized. Therefore, while positioning the housing, the yoke, and the bracket, the fixing strength of the yoke and the bracket relative to the housing can be stabilized.

[0036] Regarding the second aspect of the present invention, in the first aspect,

[0037] The first positioning protrusion, the second positioning protrusion, and the positioning recesses are three respectively. One of the three positioning recesses and the second positioning portion are arranged opposite to each other in the radial direction centered on the rotation axis.

[0038] With such a configuration, while positioning the housing, the yoke, and the bracket, the fixing strength of the yoke and the bracket relative to the housing can be reliably stabilized. In addition, the motor performance of the motor unit can be reliably improved.

[0039] Regarding the third aspect of the present invention, in the first aspect or the second aspect,

[0040] The first positioning portion is a convex portion protruding from the inner peripheral surface of the housing.

[0041] The second positioning portion is a recess into which the first positioning portion can be inserted.

[0042] A cylindrical housing can be easily formed with a convex portion by performing stamping. On the other hand, when forming a recess in the bracket, various processing methods such as forging, stamping, and casting can be adopted as the processing method. Therefore, the manufacturing cost of the motor unit can be reduced, and the variations of the manufacturing method of the motor unit can be increased.

[0043] Regarding the fourth aspect of the present invention, in any one of the first aspect to the third aspect,

[0044] The center of the permanent magnet in the circumferential direction is located in a range where the circumferential angle is -30° or more and +30° or less with respect to the butt joint surface of the metal plate.

[0045] With such a configuration, the position of the permanent magnet with respect to the yoke can be optimized, and the effective magnetic flux of the permanent magnet can be utilized to the maximum extent. Therefore, the motor performance of the motor unit can be improved.

[0046] The liquid supply device according to the fifth aspect of the present invention includes:

[0047] The motor unit described in any one of the first aspect to the fourth aspect; and

[0048] A pump section that is driven by the motor section and can pump a liquid. The bracket is the housing of the pump section.

[0049] With such a configuration, while positioning the motor section and the pump section, the fixing strength of the motor section and the pump section with respect to the outer casing can be stabilized. In addition, the motor performance of the liquid supply device can be improved.

[0050] Advantages of the Invention

[0051] According to the present invention, while positioning the outer casing, the yoke, and the bracket, the fixing strength of the yoke and the bracket with respect to the outer casing can be stabilized. In addition, the position of the permanent magnet with respect to the yoke can be optimized, and the effective magnetic flux of the permanent magnet can be utilized to the maximum extent. Therefore, the motor performance of the motor unit can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 is a perspective view of the liquid supply device according to an embodiment of the present invention.

[0053] Figure 2 is a cross-sectional view of the liquid supply device according to an embodiment of the present invention along the axial direction.

[0054] Figure 3 is a perspective view of the liquid supply device according to an embodiment of the present invention with the outer casing removed.

[0055] Figure 4 is an exploded perspective view of the outer casing, the yoke, and the pump housing according to an embodiment of the present invention.

[0056] Figure 5 is a top view of the yoke according to an embodiment of the present invention as viewed from the pump section side.

[0057] Figure 6 is a top view of the motor section according to an embodiment of the present invention as viewed from the pump section side.

[0058] Figure 7This is a top view of the upper case of the embodiment of the present invention as viewed from the upper side in the axial direction. Detailed Embodiment

[0059] Next, embodiments of the present invention will be described based on the drawings.

[0060] (Liquid Supply Device)

[0061] Figure 1 This is a perspective view of the liquid supply device 1. Figure 2 This is a cross-sectional view of the liquid supply device 1 along the axial direction.

[0062] The liquid supply device 1 is used as a fuel pump for vehicles such as motorcycles and four-wheel vehicles. The liquid supply device 1 is a so-called in-tank fuel pump disposed in a fuel tank (not shown).

[0063] As Figure 1 , Figure 2 shown, the liquid supply device 1 includes: a substantially cylindrical, metal outer shell 2; and a motor unit 3 and a pump unit 4, which are fitted to the inner peripheral surface of the outer shell 2 and arranged along the axial direction of the outer shell 2, respectively. The outer shell 2, the motor unit 3, and the pump unit 4 are arranged coaxially.

[0064] In the liquid supply device 1, the pump unit 4 is used in a direction downward in the gravitational direction. Therefore, in the following description, the motor unit 3 side may sometimes be referred to as the upper side, and the pump unit 4 side may be referred to as the lower side, etc. In addition, in the following description, the axial direction of the outer shell 2, the motor unit 3, and the pump unit 4 will be simply referred to as the axial direction, the radial direction of the outer shell 2, the motor unit 3, and the pump unit 4 will be simply referred to as the radial direction, and the circumferential direction of the outer shell 2, the motor unit 3, and the pump unit 4 will be simply referred to as the circumferential direction.

[0065] The outer shell 2 is integrally formed by a motor fitting portion 11 and a pump fitting portion 12. The motor fitting portion 11 is for fitting the motor unit 3, and the pump fitting portion 12 is formed with a reduced diameter via a step compared with the motor fitting portion 11 for fitting the pump unit 4. On the inner peripheral surface of the pump fitting portion 12, a first positioning convex portion (the first positioning portion in the solution) 13 protruding toward the radially inner side is formed. The first positioning convex portion 13 is formed, for example, by pressing the outer shell 2 from the radially outer side by stamping or the like. The first positioning convex portion 13 is formed as a rectangle that is long in the axial direction when viewed in the radial direction. In addition, an inner flange portion 12a extending radially inward is bent and extended at the lower end of the pump fitting portion 12 of the outer shell 2. These first positioning convex portions 13 and the inner flange portion 12a are used for positioning the outer shell 2 and the pump unit 4.

[0066] For example, a brushed motor is used as the motor unit 3. The motor unit 3 mainly consists of a substantially cylindrical yoke 5, a permanent magnet 8 provided on the inner peripheral surface of the yoke 5, an armature 6 rotatably provided within the yoke 5, an outlet cover 7 that closes the upper opening 5a of the yoke 5, and a brush 9 housed within the outlet cover 7.

[0067] The armature 6 mainly consists of a rotating shaft 14, an armature core 15 fitted and fixed to the outer peripheral surface of the rotating shaft 14, and a commutator 16 fitted and fixed to the outer peripheral surface of the rotating shaft 14 closer to the outlet cover 7 than the armature core 15.

[0068] The armature core 15 has a plurality of teeth 17 radially extending outward. Coils (not shown) are wound around these teeth 17. The terminal portions of the coils (not shown) are connected to the commutator 16.

[0069] The commutator 16 is a so-called disk-type commutator having a resin-made commutator body 18 formed in a substantially disk shape. A plurality of commutator segments 19 are arranged circumferentially on one surface 18a of the commutator body 18 opposite to the armature core 15. At the radially outer ends of the commutator segments 19, risers 21 are integrally formed and bent and extended toward the armature core 15 side through the outer periphery of the commutator body 18. One end of the coils (not shown) is connected to each riser 21.

[0070] The armature 6 formed in this way is almost entirely covered by a resin molding portion 22. The resin molding portion 22 is formed in a substantially cylindrical shape. In addition, the resin molding portion 22 extends between the axial center of the commutator body 18 and the side closer to the pump unit 4 than the armature core 15. Only the radially outer ends (outer peripheral surfaces) of the teeth 17 of the armature core 15 are exposed, and the coils (not shown) are buried in the resin molding portion 22. At the end of the resin molding portion 22 on the pump unit 4 side, a rounded corner portion 22a is formed at the corner. As a result, the end of the resin molding portion 22 on the pump unit 4 side becomes pointed.

[0071] The outlet cover 7 is formed in a substantially bottomed cylindrical shape with an opening 7a on the armature core 15 side. At the bottom 7b of the outlet cover 7, a bearing cylinder portion 23 protruding toward the armature core 15 is integrally formed at substantially the center in the radial direction. The upper end portion 14a of the rotating shaft 14 is rotatably supported by the bearing cylinder portion 23.

[0072] In addition, at the bottom 7b of the outlet cover 7, brush holders 24 are integrally formed on both sides with the bearing cylinder portion 23 therebetween. The brush holders 24 are formed in a box shape with an opening on the commutator 16 side. The brush 9 is slidably housed in the brush holder 24 along the axial direction. In addition, a helical spring 26 is housed in the brush holder 24 in a compressed and deformed state. The brush 9 is biased toward the commutator 16 side by the helical spring 26. The front end of the brush 9 protrudes from the brush holder 24 and makes sliding contact with the commutator segment 19.

[0073] In addition, a terminal 27 penetrating the bottom 7b in the vertical direction is provided at the bottom 7b of the outlet cover 7. The brush 9 is connected to the terminal 27 via a lead (not shown). An external power supply (not shown) is connected to the terminal 27. Thus, external power is supplied to a coil (not shown) via the terminal 27, the lead (not shown), the brush 9, and the commutator segment 19.

[0074] In addition, a discharge port 28 protruding upward is integrally formed at the bottom 7b of the outlet cover 7. The discharge port 28 is a part for discharging the fuel sucked by the liquid supply device 1 and is connected to a fuel flow path (not shown). In addition, the inside and outside of the outlet cover 7 are communicated via the discharge port 28.

[0075] A positioning piece 32 extending downward is integrally formed on the peripheral wall 7c of the outlet cover 7. The positioning piece 32 is sandwiched between the permanent magnets 8 to position the permanent magnets 8 (yoke 5) and the outlet cover 7. In addition, as Figure 3 shown, a positioning convex portion 33 extending downward is integrally formed at the peripheral wall 7c of the outlet cover 7. The extension length of the positioning convex portion 33 is set to be sufficiently shorter than the extension length of the positioning piece 32. The positioning convex portion 33 performs circumferential positioning of the outlet cover 7 and the yoke 5.

[0076] In addition, at the peripheral wall 7c of the outlet cover 7, a fitting rib portion 29 protruding radially outward is formed over the entire circumference of the outer peripheral surface. The outer diameter of the fitting rib portion 29 is set to be substantially the same as the inner diameter of the motor fitting portion 11 of the housing 2. The outer peripheral surface of the fitting rib portion 29 like this is fitted to the inner peripheral surface of the motor fitting portion 11. The lower side of the peripheral wall 7c of the outlet cover 7 than the fitting rib portion 29 is formed as a socket portion 31 that is socket-connected to the yoke 5.

[0077] (Yoke)

[0078] Figure 3 is a perspective view of the liquid supply device 1 with the housing 2 removed. Figure 4 is an exploded perspective view of the housing 2, the yoke 5, and the pump housing 41 described later.

[0079] The yoke 5 forms a magnetic path through which the magnetic flux of the permanent magnets 8 passes. As Figures 2 to 4 shown, the yoke 5 is formed using, for example, a progressive stamping device. The yoke 5 is formed into a substantially cylindrical shape by performing stamping on a single metal plate, for example, and bending it. The yoke 5 has a butting surface 5c that butts the circumferential ends against each other (the ends in the long dimension direction of a single metal plate).

[0080] The upper opening portion 5a of the yoke 5 is fitted onto the outer peripheral surface of the socket portion 31 of the outlet cover 7. At the periphery of the upper opening portion 5a of the yoke 5, at a position corresponding to the positioning convex portion 33 of the outlet cover 7, a yoke positioning concave portion 34 into which the positioning convex portion 33 can be inserted is formed. By inserting the positioning convex portion 33 into the yoke positioning concave portion 34, circumferential positioning of the outlet cover 7 and the yoke 5 is performed.

[0081] At the periphery of the lower opening portion 5b of the yoke 5, at a position avoiding the butt joint surface 5c, a plurality (three in this embodiment) of first positioning protrusions (the first positioning protrusions in the solution) 35 are formed extending toward the pump portion 4 side. The first positioning protrusions 35 perform circumferential positioning of the yoke 5 and the pump portion 4.

[0082] In addition, at the periphery of the lower opening portion 5b of the yoke 5, at a position avoiding the butt joint surface 5c, a plurality (three in this embodiment) of second positioning protrusions (the second positioning protrusions in the solution) 36 are formed. For the second positioning protrusions 36, recesses 36a are formed on both circumferential sides of the portion where the second positioning protrusions 36 are formed at the periphery of the lower opening portion 5b of the yoke 5, whereby the second positioning protrusions 36 are shaped to protrude from the periphery of the lower opening portion 5b toward the pump portion 4 side. The second positioning protrusions 36 are used, for example, for positioning relative to the progressive machining device.

[0083] Here, based on Figure 5 The positioning methods for the first positioning protrusions 35 and the second positioning protrusions 36 will be elaborated in detail.

[0084] Figure 5 is a top view of the yoke 5 as viewed from the pump portion 4 side.

[0085] As Figure 5 shown, when the number of the first positioning protrusions 35 is set as N1, the circumferential arrangement positions of the first positioning protrusions 35 are set such that the circumferential angle α around the axis C of the rotation axis 14 between adjacent first positioning protrusions 35 satisfies

[0086] α = 360° / N1 ± 30° ……(1)

[0087] In other words, the angle α is set such that 360° / N1 - 30° ≤ α ≤ 360° / N1 + 30°. In this embodiment, the number N1 of the first positioning protrusions 35 is three, and the first positioning protrusions 35 are arranged as Figure 5 shown, with α1, α2, and α3 being approximately 120°.

[0088] In addition, when the number of the second positioning protrusions 36 is set as N2, the circumferential arrangement positions of the second positioning protrusions 36 are set such that the circumferential angle β around the axis C of the rotation axis 14 between adjacent second positioning protrusions 36 satisfies

[0089] β = 360° / N2 ± 30°……(2)

[0090] In other words, the angle β is set to 360° / N2 - 30° ≤ β ≤ 360° / N2 + 30°. In the present embodiment, the number N2 of the second positioning protrusions 36 is three, and the second positioning protrusions 36 are arranged such that Figure 5 the β1, β2, and β3 shown are approximately 120°.

[0091] Moreover, the first positioning protrusion 35 and the second positioning protrusion 36 respectively satisfy the arithmetic expressions (1) and (2), and are arranged at positions that do not overlap with each other in the circumferential, radial, and axial directions.

[0092] Figure 6 is a top view of the motor unit 3 as viewed from the pump unit 4 side (lower side).

[0093] As Figure 2 , Figure 6 shown, two permanent magnets 8 are provided on the inner peripheral surface of the yoke 5. When viewed axially, the permanent magnets 8 are formed in a substantially semicircular shape along the inner peripheral surface of the yoke 5. The axial length of the permanent magnets 8 is set to be longer than the axial length of the armature core 15. Moreover, both axial ends of the permanent magnets 8 are arranged to protrude (overhang) from both axial ends of the armature core 15. The magnetic field orientation of the permanent magnets 8 is along the radial direction (the thickness direction of the permanent magnets 8).

[0094] Such permanent magnets 8 are arranged to face each other in the radial direction with the rotation axis 14 as the center. In addition, one of the two permanent magnets 8 is arranged such that the circumferential center C1 is within the range Ar1 of ±30° in the circumferential direction with respect to the butt surface 5c of the yoke 5. In other words, the center C1 of one of the permanent magnets 8 is arranged within the range of an angle of -30° or more and +30° or less in the circumferential direction with the butt surface 5c as a reference (i.e., the angle is 0). A minute gap is formed between the inner peripheral surface of the permanent magnet 8 and the radially outer end of the tooth 17 of the armature core 15.

[0095] (Pump unit)

[0096] As Figures 2 to 4 shown, the lower end portion of the rotation axis 14 is inserted into the pump unit 4.

[0097] The pump unit 4 uses a non-positive displacement pump having an impeller 40. The pump unit 4 is composed of the impeller 40 and a pump casing 41 formed to cover the entire impeller 40. The pump casing 41 is fitted into the pump fitting portion 12 of the outer casing 2.

[0098] The impeller 40 is a member made of a resin material and formed in a substantially disc shape. The lower end portion 14b of the rotation axis 14 is connected to a position slightly central in the radial direction of the impeller 40. Thus, the rotation axis 14 and the impeller 40 rotate integrally.

[0099] On the outer peripheral sides of the upper surface and the lower surface of the impeller 40, a plurality of blade portions (not shown) are formed. Further, the lower surface and the upper surface of the impeller 40 are penetrated between the plurality of blade portions. Moreover, a fuel flow path hole (not shown) that penetrates the upper surface and the lower surface of the impeller 40 is formed between the radial center of the impeller 40 and the blade portions.

[0100] (Pump housing)

[0101] The pump housing 41 that covers the entire impeller 40 is composed of an upper housing 43, a middle housing 44, and a lower housing 42.

[0102] Figure 7 FIG. is a plan view for observing the upper housing 43 from the upper side in the axial direction.

[0103] As Figures 2 to 4 , Figure 7 shown, the upper housing 43 is disposed on the motor portion 3 side of the impeller 40. The upper housing 43 is formed in a substantially disc shape so as to cover the upper surface of the impeller 40. The middle housing 44 is joined to the outer peripheral portion of the upper housing 43. The outer diameter of the upper housing 43 is set to be slightly smaller than the outer diameter of the yoke 5.

[0104] An insertion hole 46 through which the lower end portion 14b of the rotary shaft 14 can be inserted is formed at the radial center of the upper housing 43. Further, a substantially annular concave portion 47 is formed on the upper surface 43a of the upper housing 43 so as to surround the periphery of the insertion hole 46. In the upper surface 43a of the upper housing 43, the portion on the outer peripheral side of the concave portion 47 becomes a contact surface 43b against which the yoke 5 abuts. Further, on the upper surface 43a of the upper housing 43, a discharge port 48 that penetrates the upper housing 43 in the vertical direction is formed near the outer peripheral portion of the concave portion 47. Fuel is discharged from the discharge port 48 (specific details will be described later).

[0105] On the outer peripheral surface 43c of the upper housing 43, at positions corresponding to the first positioning protrusions 35 of the yoke 5, a plurality of (three in this embodiment) first housing positioning concave portions (positioning concave portions in the solution) 45 into which the first positioning protrusions 35 can be inserted are formed. Since the positions of the first housing positioning concave portions 45 correspond to the positions of the first positioning protrusions 35, they are arranged at intervals of approximately 120° in the circumferential direction. The discharge port 48 is located near one of the three first housing positioning concave portions 45.

[0106] By inserting the first positioning protrusions 35 into the first housing positioning concave portions 45, circumferential positioning of the yoke 5 with respect to the pump housing 41 is performed. In a state where the first positioning protrusions 35 are inserted into the first housing positioning concave portions 45, the lower end (the peripheral edge of the lower opening portion 5b) of the yoke 5 abuts against the contact surface 43b of the upper housing 43. That is, the second positioning protrusions 36 of the yoke 5 abut against the contact surface 43b of the upper housing 43. Thereby, axial positioning of the yoke 5 with respect to the pump housing 41 is performed.

[0107] The middle housing 44 is formed in a substantially annular shape so as to surround the outer peripheral surface of the impeller 40. The middle housing 44 is integrally formed with the upper housing 43. The outer diameter of the middle housing 44 is set to be slightly larger than the outer diameter of the upper housing 43. Through the middle housing 44, the radial center of the impeller 40 coincides with the axis C of the rotating shaft 14. The axial thickness of the middle housing 44 is formed to be substantially the same as or slightly thicker than the axial thickness of the impeller 40. Thereby, a predetermined gap is respectively formed between the impeller 40 and the upper housing 43 and between the impeller 40 and the lower housing 42.

[0108] On the outer peripheral surface 43c of the upper housing 43 and the outer peripheral surface 44a of the middle housing 44, a second housing positioning recess (the second positioning portion in the embodiment) 51 extending in the axial direction is formed. The second housing positioning recess 51 is formed to allow the first positioning convex portion 13 of the outer housing 2 to be inserted therein. The second housing positioning recess 51 is disposed between the first housing positioning recesses 45 adjacent in the circumferential direction. More specifically, the first housing positioning recess 45 near the discharge port 48 among the three first housing positioning recesses 45 and the second housing positioning recess 51 are disposed at positions radially opposed with the insertion through-hole 46 (rotating shaft 14) as the center.

[0109] The lower housing 42 is disposed below the impeller 40. The pump housing 41 is formed such that the upper housing 43 integrally formed with the middle housing 44 and the lower housing 42 cover the entire impeller 40.

[0110] The lower housing 42 is formed in a substantially circular plate shape. The outer diameter of the lower housing 42 is set to be substantially the same as the outer diameter of the middle housing 44. On the outer peripheral surface 42a of the lower housing 42, a third housing positioning recess (the second positioning portion in the embodiment) 52 communicating with the second housing positioning recess 51 of the upper housing 43 and the middle housing 44 is formed. The circumferential width and depth of the third housing positioning recess 52 are set to be substantially the same as the circumferential width and depth of the second housing positioning recess 51. Therefore, the third housing positioning recess 52 is formed to allow the first positioning convex portion 13 of the outer housing 2 to be inserted therein.

[0111] On the lower surface 42b of the lower housing 42, the lower end portion 14b of the rotating shaft 14 is rotatably supported at the radial center. On the lower surface 42b of the lower housing 42, a fuel suction port 53 protruding downward is formed on the outer peripheral side. The fuel suction port 53 is formed in a cylindrical shape. The inner peripheral surface side of the fuel suction port 53 serves as a passage for fuel. Fuel is sucked into the pump housing 41 through the fuel suction port 53.

[0112] In addition, on the lower surface 42b of the lower housing 42, a stepped portion 49 is formed at the outer peripheral edge. The stepped portion 49 is formed by reducing the diameter of the lower surface 42b side of the lower housing 42. When viewed axially, the stepped portion 49 is formed at a position overlapping with the inner flange portion 12a of the outer housing 2.

[0113] A corner ring 50, which serves as a sealing member, is installed on the stepped portion 49. The corner ring 50 is a member having a substantially rectangular cross-section and made of a material with excellent oil resistance such as fluororubber. The outer diameter of the corner ring 50 is set slightly smaller than the outer diameter of the lower housing 42. Therefore, the outer peripheral surfaces of the upper housing 43, the middle housing 44, and the lower housing 42 are fitted into the pump fitting portion 12 of the housing 2. A minute gap is formed between the outer peripheral surface of the corner ring 50 and the inner peripheral surface of the pump fitting portion 12 of the housing 2.

[0114] (Assembly method of the liquid supply device)

[0115] Next, the assembly method of the liquid supply device 1 will be described.

[0116] First, the motor unit 3 and the pump unit 4 are assembled in advance. Then, the first positioning protrusion 35 of the yoke 5 is inserted into the first housing positioning recess 45 of the pump housing 41. Thereby, the circumferential positioning of the motor unit 3 and the pump unit 4 is performed.

[0117] Next, the lower end of the yoke 5 is brought into contact with the contact surface 43b of the upper housing 43. Thereby, the axial positioning of the motor unit 3 and the pump unit 4 is performed, and the motor unit 3 and the pump unit 4 are integrated. Here, the contact surface 43b is formed on the upper surface 43a of the upper housing 43, ensuring sufficient space. Therefore, even if the lower end of the yoke 5 is brought into contact with the contact surface 43b, these contact surface 43b and the yoke 5 will not be buckled and deformed.

[0118] After that, the motor unit 3 and the pump unit 4 are fitted into the inner peripheral surface of the housing 2. At this time, from the upper opening edge portion 11a of the motor fitting portion 11 of the housing 2, the pump unit 4 and the motor unit 3 are inserted into the housing 2 in this order. In addition, at this time, the positions of the first positioning convex portion 13 of the housing 2, the second housing positioning recess 51 of the pump housing 41, and the third housing positioning recess 52 are aligned. Then, the motor unit 3 and the pump unit 4 are inserted into the housing 2 in such a manner that the first positioning convex portion 13 is inserted into the second housing positioning recess 51 and the third housing positioning recess 52. Thereby, the circumferential positioning of the motor unit 3 and the pump unit 4 with respect to the housing 2 is performed.

[0119] Here, the first positioning protrusion 35 of the yoke 5 and the first housing positioning recess 45 of the pump housing 41 for performing the circumferential positioning of the motor unit 3 and the pump unit 4, the first positioning convex portion 13 of the housing 2 and the second housing positioning recess 51 of the pump housing 41 for performing the circumferential positioning of the housing 2 and the pump unit 4 (motor unit 3), and the third housing positioning recess 52 are circumferentially offset from each other. Therefore, since the circumferential positioning of the motor unit 3 and the pump unit 4 and the circumferential positioning of the housing 2 and the pump unit 4 (motor unit 3) are performed independently, each positioning is stable.

[0120] In addition, the first positioning protrusion 35 and the second positioning protrusion 36 formed on the yoke 5 are respectively formed to avoid the butting surface 5c of the yoke 5. On this basis, the circumferential arrangement position of the first positioning protrusion 35 is set to satisfy the above formula (1). In addition, the circumferential arrangement position of the second positioning protrusion 36 is set to satisfy the above formula (2). Therefore, the fixing strength of the motor unit 3 and the pump unit 4 is evenly dispersed in the circumferential direction.

[0121] After that, the corner ring 50 installed at the lower case 42 of the pump unit 4 is brought into contact with the inner flange portion 12a of the outer shell 2. Then, through the stepped portion 49 of the lower case 42 and the inner flange portion 12a, with the corner ring 50 slightly flattened, the upper opening edge portion 11a of the motor fitting portion 11 is caulked from above the fitting rib portion 29 of the outlet cover 7 toward the radially inner side. Thus, the pump unit 4 is fitted into the pump fitting portion 12 of the outer shell 2. In addition, the motor unit 3 is fitted into the motor fitting portion 11 of the outer shell 2. And these outer shell 2, motor unit 3, and pump unit 4 are integrated. In addition, the sealing between the outer shell 2 and the pump unit 4 is ensured by the corner ring 50. Through the above, the assembly of the liquid supply device 1 is completed.

[0122] (Operation of the liquid supply device)

[0123] Next, the operation of the liquid supply device 1 will be described.

[0124] When the rotating shaft 14 of the motor unit 3 is rotated, the impeller 40 and the rotating shaft 14 rotate integrally. Then, the fuel passes through the unillustrated fuel flow path holes of the impeller 40 and is pumped from the lower side to the upper side of the impeller 40. After that, the fuel is discharged into the yoke 5 of the motor unit 3 via the discharge port 48 of the upper case 43. The fuel discharged into the yoke 5 is pumped to the discharge port 28 through the minute gap between the permanent magnet 8 and the resin molding portion 22 (the radially outer end of the tooth 17 of the armature core 15). After that, the fuel is pumped to an unillustrated engine or the like via the discharge port 28.

[0125] In this way, in the above embodiment, the upper surface 43a of the upper case 43 is used as the butting surface 43b against which the lower end of the yoke 5 abuts. Therefore, even when the lower end of the yoke 5 abuts against the butting surface 43b, it is possible to prevent the butting surface 43b and the yoke 5 from being buckled and deformed. In particular, as in this embodiment, even when the commutator 16 is a disk-type commutator and the brush 9 presses the commutator 16 axially through the spiral spring 26, it is possible to prevent the butting surface 43b and the yoke 5 from being buckled and deformed. For example, when adopting a structure in which the upper case 43 is fitted into the inner circumferential surface of the yoke 5, it is difficult to ensure the space for the butting surface 43b, and when trying to ensure this space, the upper case 43 will be enlarged. On the other hand, in the above embodiment, the liquid supply device 1 can be miniaturized.

[0126] In addition, the first positioning protrusion 35 of the yoke 5 for circumferentially positioning the motor unit 3 and the pump unit 4, the first housing positioning recess 45 of the pump housing 41, the first positioning convex portion 13 of the outer housing 2 for circumferentially positioning the outer housing 2 and the pump unit 4 (motor unit 3), and the second and third housing positioning recesses 51 and 52 of the pump housing 41 are offset from each other circumferentially. Therefore, since the circumferential positioning of the motor unit 3 and the pump unit 4 and the circumferential positioning of the outer housing 2 and the pump unit 4 (motor unit 3) are carried out independently, the positioning of each can be made stable.

[0127] In addition, the first positioning protrusion 35 and the second positioning protrusion 36 formed on the yoke 5 are respectively formed so as to avoid the butting surface 5c of the yoke 5. On this basis, the circumferential arrangement position of the first positioning protrusion 35 is set to satisfy the above formula (1). In addition, the circumferential arrangement position of the second positioning protrusion 36 is set to satisfy the above formula (2). Therefore, the fixing strength of the motor unit 3 and the pump unit 4 is evenly dispersed circumferentially. It should be noted that the item "±30°" in the above formulas (1) and (2) is because if it is within this range, the fixing strength of the motor unit 3 and the pump unit 4 can be evenly dispersed circumferentially.

[0128] Therefore, the fixing strength of the motor unit 3 and the pump unit 4 relative to the outer housing 2 can be made stable.

[0129] In addition, one of the two permanent magnets 8 is arranged such that the circumferential center C1 is located within the range Ar1 of ±30° circumferentially with respect to the butting surface 5c of the yoke 5. Since the permanent magnet 8 is magnetically oriented in the radial direction (the thickness direction of the permanent magnet 8), the magnetic flux density at both circumferential ends is larger than that at the circumferential center. Therefore, by making the butting surface 5c of the yoke 5, which is likely to obstruct the magnetic path, coincide with the circumferential center C1 of the permanent magnet 8 as much as possible, the effective magnetic flux of the permanent magnet 8 can be utilized to the maximum extent. Thereby, the motor performance of the motor unit 3 can be improved.

[0130] In addition, three first positioning protrusions 35, second positioning protrusions 36, and first housing positioning recesses 45 are respectively provided. And at a position radially opposed to the first housing positioning recess 45 near the discharge port 48 among the three first housing positioning recesses 45 with the insertion hole 46 as the center, the second housing positioning recess 51 is arranged. Therefore, while positioning the outer housing 2, the yoke 5, and the pump housing 41, the fixing strength of the yoke 5 and the pump housing 41 relative to the outer housing 2 can be reliably made stable. In addition, the motor performance of the motor unit 3 can be reliably improved.

[0131] In addition, when circumferentially positioning the outer shell 2 and the pump housing 41, the outer shell 2 is pressed from the radially outer side by stamping or the like, thereby forming the first positioning convex portion 13. Further, recesses (the second housing positioning recess 51 and the third housing positioning recess 52) for inserting the first positioning convex portion 13 are formed in the pump housing 41. In this way, the substantially cylindrical, metallic outer shell 2 can easily form a convex portion (the first positioning convex portion 13) by performing stamping. On the other hand, when forming recesses (the second housing positioning recess 51 and the third housing positioning recess 52) in the pump housing 41, various processing methods such as forging, stamping, and casting can be adopted as the processing method. Therefore, the manufacturing cost of the liquid supply device 1 can be reduced, and the variations of the manufacturing method of the liquid supply device 1 can be increased.

[0132] It should be noted that the present invention is not limited to the above-described embodiments, and also includes embodiments in which various changes are added to the above-described embodiments without departing from the gist of the present invention.

[0133] For example, in the above-described embodiment, the liquid supply device 1 as a fuel pump for motorcycles, four-wheel vehicles, etc. has been described. However, the configuration of the above-described embodiment can also be applied to a case where a bracket or the like is provided in the motor unit 3 without having a pump unit 4. In this case, the pump housing 41 in the above-described embodiment may be set as the bracket. More specifically, the upper housing 43 may be set as the bracket, and the configuration of the abutting surface 43b and the outer peripheral surface 43c may be adopted for the bracket.

[0134] In addition, in the above-described embodiment, a case where three first positioning protrusions 35, three second positioning protrusions 36, and three first housing positioning recesses 45 are respectively provided has been described. However, it is not limited thereto, and they may be three or more respectively. When the number of the first positioning protrusions 35 is set to N1, the circumferential arrangement positions of the first positioning protrusions 35 only need to satisfy the above-described formula (1). In addition, when the number of the second positioning protrusions 36 is set to N2, the circumferential arrangement positions of the second positioning protrusions 36 only need to satisfy the above-described formula (2). In addition to this, the first positioning protrusion 35 and the second positioning protrusion 36 only need to be arranged at positions that do not overlap each other in the circumferential, radial, and axial directions. On the basis of these, ideally, one of the plurality of first housing positioning recesses 45 in the pump housing 41 is located at a position radially opposed to the second housing positioning recess 51 and the third housing positioning recess 52 with the insertion hole 46 (the rotation shaft 14) as the center.

[0135] In addition, in the above-described embodiment, a case where a brushed motor is adopted as the motor unit 3 has been described. However, it is not limited thereto, and for example, a brushless motor may be adopted as the motor unit 3.

[0136] This application is based on Japanese Patent Application No. 2019-005221 filed on January 16, 2019, the content of which is incorporated herein by reference.

[0137] Industrial Applicability

[0138] According to the motor unit and the liquid supply device of the present invention, for example, each part can be positioned and the fixing strength relative to the housing can be stabilized, and the motor performance can be improved. The present invention that exhibits such an effect is useful for fuel pumps for vehicles such as motorcycles and four-wheel vehicles.

[0139] Explanation of Reference Numerals:

[0140] 1: Liquid supply device;

[0141] 2: Housing;

[0142] 3: Motor part (motor unit);

[0143] 4: Pump part;

[0144] 5: Yoke;

[0145] 8: Permanent magnet;

[0146] 13: First positioning convex part (first positioning part);

[0147] 14: Rotating shaft;

[0148] 35: First positioning protrusion;

[0149] 36: Second positioning protrusion;

[0150] 41: Pump housing (motor unit, housing);

[0151] 43: Upper housing (bracket);

[0152] 43a: Upper surface (one end);

[0153] 45: First housing positioning recess (positioning recess);

[0154] 51: Second housing positioning recess (second positioning part);

[0155] 52: Third housing positioning recess (second positioning part);

[0156] Ar1: Range;

[0157] C1: Circumferential center.

Claims

1. A motor unit, comprising: A housing, which is cylindrical; A bracket, which is disc-shaped and is fitted on the inner peripheral surface of the housing; and A motor part, which is arranged inside the housing and is coaxially arranged with the bracket, The motor part has: A yoke, which is fitted on the inner peripheral surface of the housing and is formed by a single metal plate bent into a cylindrical shape; and A plurality of permanent magnets, which are arranged on the inner peripheral surface of the yoke, An end face in the axial direction of the bracket contacts with one end portion of the yoke on the bracket side, The housing has: A first positioning part, which is formed at a position corresponding to the bracket and is used for positioning the housing and the bracket, The yoke has: A plurality of first positioning protrusions, which are arranged to protrude from the one end portion toward the bracket side at a position avoiding the butt joint surface of the metal plate and are used for positioning the yoke and the bracket; and A plurality of second positioning protrusions, which are arranged to protrude from the one end portion toward the bracket side at a position avoiding the butt joint surface and are used for positioning the yoke relative to the device for conveying the yoke, The bracket has: A second positioning part, which can be engaged with the first positioning part; and A plurality of positioning recesses, into which the plurality of first positioning protrusions are respectively inserted, One of the second positioning part and the plurality of positioning recesses is separately arranged on both sides with the rotation axis of the motor part as the center, When the number of the first positioning protrusions is set as N1, the circumferential angle around the rotation axis between adjacent first positioning protrusions is 360° / N1 - 30° or more and 360° / N1 + 30° or less, When the number of the second positioning protrusions is set as N2, the circumferential angle between adjacent second positioning protrusions is 360° / N2 - 30° or more and 360° / N2 + 30° or less, The first positioning protrusion, the second positioning protrusion and the first positioning part are arranged at positions that do not overlap with each other in the circumferential direction, radial direction and axial direction.

2. The motor unit according to claim 1, wherein The first positioning protrusion, the second positioning protrusion and the positioning recess are respectively three, One of the three positioning recesses and the second positioning part are arranged opposite to each other in the radial direction with the rotation axis as the center.

3. The motor unit according to claim 1 or 2, wherein The first positioning part is a convex part protruding from the inner peripheral surface of the housing, The second positioning part is a concave part into which the first positioning part can be inserted.

4. The motor unit according to claim 1 or 2, wherein The center of the permanent magnet in the circumferential direction is within a range where the circumferential angle is -30° or more and +30° or less based on the butt joint surface of the metal plate.

5. A liquid supply device, comprising: The motor unit according to claim 1 or 2; and A pump part, which is driven by the motor part and can pump liquid, The bracket is a housing of the pump part.

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