Stator unit manufacturing method

Abstract

To enable a coil wire of a coil provided in a motor stator to be efficiently, accurately, and moreover firmly bonded to a terminal of a bus bar.SOLUTION: A manufacturing method for a stator unit 1 includes a fusing step for temporarily fixing a coil wire 6 of a coil 5 provided on a motor stator 2 to a terminal 12 of a bus bar 11 and then fusing the terminal 12 to bond the coil wire 6 to the terminal 12. In the step for temporarily fixing the coil wire 6 to the terminal 12, an arc portion 12a, whose inscribed circle diameter is larger than a wire diameter D of the coil wire 6 and whose inner diameter surface configures a surface S to be jointed with the terminal 12 and first and second sealing portions 12d and 12e that seal an opening part of the arc portion 12a in cooperation with the mating side, are formed on the terminal 12 in a state in which the outer circumferential surface of the coil wire 6 is arranged facing the surface S to be joined.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a Stator unit manufacturing method constituting the stationary side of a motor.

Background Art

[0002] In a motor in which a coil provided on a motor stator is electrically connected to an external power source via a bus bar, the coil wire and the terminal of the bus bar (hugging terminal) may be joined by hugging. Hugging is a method of joining a coil wire and a terminal by applying pressure to a terminal holding (temporarily fixing) the coil wire with a pair of electrodes in the wire diameter direction of the coil wire and energizing between the pair of electrodes. Simply put, it is heat caulking using electrical resistance. In hugging, the insulating coating of the coil wire made of a conductor with an insulating coating is removed, and at the same time, the conductor of the coil wire is joined to the terminal of the bus bar, so that the connection work between the coil wire and the bus bar can be efficiently performed.

[0003] For example, Patent Document 1 below describes a hugging terminal formed in a substantially W (M) - shaped cross - section integrally having first and second main body parts facing each other, a first bent part provided at one end of the first main body part, a second bent part provided at one end of the second main body part, and a protrusion part connecting both bent parts. According to this hugging terminal, since a protrusion part is provided between both main body parts, the plate thickness (the separation distance between the first main body part and the second main body part arranged opposite to each other) can be increased, so that excessive crushing of the conductor due to hugging and disconnection of the conductor caused thereby can be prevented.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Incidentally, the fusing terminal described in Patent Document 1 is obtained by first "forming first and second main body parts on both sides of a projection by press-molding a projection onto a strip-shaped conductive plate material," and then "forming a first bent portion on the first main body part and a second bent portion on the second main body part so that the two main body parts face each other with the projection in between" (paragraph 0010 of Patent Document 1). As such, the fusing terminal described in Patent Document 1 has a complex shape and is manufactured through multiple processes (mold equipment), making it prone to variations in shape and high cost. Variations in the shape of the fusing terminal lead to variations in the processing accuracy during fusing (amount of heat generated when energized, amount of crushing of the conductor, etc.), making it difficult to stably secure the required bonding strength between the coil wire and the fusing terminal.

[0006] Furthermore, when joining a coil wire to the fusing terminal described in Patent Document 1, it is necessary to perform the following operation before temporarily fixing the coil wire to the fusing terminal: "bend and straighten the second main body of the fusing terminal, which is formed into a predetermined shape, and place the coil wire near the protruding part" (paragraph 0011 of Patent Document 1). In practice, this operation would have to be performed manually, which would result in a considerable amount of effort being required for fusing.

[0007] In view of the above circumstances, the main objective of the present invention is to enable efficient, precise, and robust joining of the coil wires of a coil provided in a motor stator to the terminals of a busbar, thereby enabling the efficient manufacturing (mass production) of a stator unit with high durability and reliability. [Means for solving the problem]

[0008] The present invention, devised to achieve the above objective, is a method for manufacturing a stator unit, comprising a temporary fixing step of temporarily fixing the coil wire of a coil provided on a motor stator to the terminal of a busbar, and a fusing step of joining the coil wire to the terminal by fusing the terminal holding the coil wire. In the temporary fixing step, with the outer surface of the coil wire facing the intended joining surface of the terminal, the coil wire is temporarily fixed to the terminal by forming an arc portion on the terminal, where the diameter of the inscribed circle is larger than the diameter of the coil wire and the inner diameter surface constitutes the intended joining surface, and first and second sealing portions that cooperate with the other side to seal the opening of the arc portion. The "opening of the arc portion" as used herein refers to a divided portion of the circular trajectory passing through the arc portion.

[0009] According to the present invention, the terminal shape of the busbar that holds the coil wire is significantly simplified compared to the terminal shape of the busbar described in Patent Document 1. In addition, since the terminal is formed in a predetermined shape (the terminal is deformed into a predetermined shape) during the temporary fixing process, and the coil wire is held at the terminal at the same time, the work required to perform fusing can be carried out efficiently and accurately.

[0010] Furthermore, in this invention, among the terminals consisting of an arc portion, a first sealing portion, and a second sealing portion formed in the temporary fixing process, the arc portion whose inner diameter surface constitutes the intended joining surface for the coil wire is formed with an inscribed circle diameter larger than the wire diameter of the coil wire. In this case, when fusing is performed on the terminal to which the coil wire has been temporarily fixed, the coil wire can be brought into proper contact with the inner diameter surface (intended joining surface) of the arc portion. This makes it possible to stably secure the required joining strength between the coil wire and the terminal.

[0011] In the above configuration, the first sealing portion and the second sealing portion may have parallel straight sections. This makes it difficult for the coil wire temporarily fixed to the terminal to come off the terminal, which is advantageous for performing fusing properly and accurately.

[0012] In the above configuration, during the temporary fixing process, with the outer surface of the coil wire protruding axially outward from the motor stator facing the intended joining surface of the terminal, the terminal consisting of the arc portion, the first sealing portion, and the second sealing portion may be formed by moving a molding die positioned on either the radially outer or radially inner side of the terminal toward the stationary die positioned on the other side and clamping the molds. In this way, a terminal of a predetermined shape (a terminal holding the coil wire in a predetermined manner) can be easily obtained.

[0013] In order to accurately connect the coil wires to the busbar terminals, it is preferable to perform the above-mentioned temporary fixing and fusing processes while restricting the relative movement of the busbar unit that holds the motor stator and busbar.

[0014] As a technical means for restricting the relative movement of the busbar unit with respect to the motor stator, for example, a snap-fit ​​structure can be employed in which a claw portion provided on either the busbar unit or the motor stator is fitted into a claw receiving portion provided on the other.

[0015] Furthermore, in order to achieve the above objectives, the present invention provides a stator unit comprising a motor stator provided with a coil and a busbar unit holding a busbar that electrically connects the coil to an external power supply, wherein the busbar unit is positioned axially outward of the motor stator, and wherein the coil wires of the coil are joined to the terminals of the busbar by fusing, and a snap-fit ​​structure is provided in which a claw portion provided on either the motor stator or the busbar unit is fitted into a claw receiving portion provided on the other, thereby restricting at least the circumferential movement of the busbar unit relative to the motor stator and the axial separation movement of the busbar unit relative to the motor stator.

[0016] According to such a configuration, in a state where the snap-fit structure is formed, relative movement of the bus bar unit with respect to the motor stator (specifically, circumferential movement and axial separation movement) can be restricted, so that the conductor wire (of the coil wire) and the terminal of the bus bar can be efficiently and accurately joined by fusing.

Advantages of the Invention

[0017] From the above, according to the present invention, it is possible to efficiently, accurately, and firmly join the coil wire of the coil provided in the motor stator and the terminal of the bus bar. Thereby, a stator unit rich in durability and reliability can be efficiently manufactured.

Brief Description of the Drawings

[0018] [Figure 1] It is an exploded perspective view of the stator unit. [Figure 2] It is a schematic perspective view of the stator unit. [Figure 3] (a) The figure is a plan view of the terminal before the temporary fixing process is carried out, and (b) the figure is a plan view of the terminal after the temporary fixing process is carried out. [Figure 4] It is a figure for explaining an embodiment of the temporary fixing process. (a) The figure shows an initial stage of the process, (b) the figure shows an intermediate stage of the process, and (c) the figure shows a final stage of the process. [Figure 5] It is a front view showing the coil wire and the terminal of the bus bar extracted. [Figure 6] It is a plan view for explaining an embodiment of the fusing process. [Figure 7] It is a longitudinal sectional view of an electric pump in which the stator unit according to an embodiment of the present invention is used. [Figure 8] (a) The figure is a cross-sectional view of a part of the housing of the electric pump that houses the motor, and (b) the figure shows a state where the stator unit according to an embodiment of the present invention is incorporated into the motor housing part of the housing.

Mode for Carrying Out the Invention

[0019] Hereinafter, embodiments of the present invention will be described based on the drawings. For convenience, first, the overall structure of the stator unit 1 will be briefly described based on the exploded perspective view shown in FIG. 1 and the perspective view of the assembled state (completed product state) shown in FIG. 2, and then the manufacturing method of the stator unit 1 according to the embodiment of the present invention will be described. Although the illustration of the coil wire 6 is omitted in FIG. 2, in the actual stator unit 1, the conductor wires of the coil wire 6 are joined to the respective terminals 12 by the method described in detail later.

[0020] The stator unit 1 constitutes the stationary side of a motor (inner rotor type three-phase brushless motor) and includes a motor stator 2 and a bus bar unit 10 arranged coaxially. That is, in this stator unit 1, the coil 5 provided in the motor stator 2 is electrically connected to an external power source via the bus bar 11 held by the bus bar unit 10.

[0021] The motor stator 2 includes a stator core 3 having a plurality (here, 12) of teeth 4 arranged at intervals in the circumferential direction, an insulator 7 attached to the stator core 3, and a coil 5 formed by winding a coil wire 6 made of a coated conductor around each tooth 4. The insulator 7 is formed of an insulating material such as resin and integrally has a portion covering the teeth 4 of the stator core 3 and an annular portion covering the end face of the stator core 3. Therefore, the coil 5 is formed by winding the coil wire 6 around the teeth 4 via the insulator 7.

[0022] The busbar unit 10 comprises a plurality of busbars 11 made of a metal material with excellent electrical conductivity, such as copper or aluminum, and a busbar holder 13 made of an insulating material such as resin, which holds the plurality of busbars 11 in a non-contact state. The busbar holder 13 integrally has a claw portion 14 that extends axially along the outer circumferential surface of the annular portion that holds the busbars 11, and a protrusion portion 15 that protrudes outward from the outer diameter side of the annular portion, in order to position the busbar unit 10 with respect to the motor stator 2 in the axial, circumferential, and radial directions. In this case, three claw portions 14 and three protrusion portions 15 are provided alternately at intervals in the circumferential direction.

[0023] Each busbar 11 has an integrated terminal 12 to which the coil wire 6 of the corresponding coil 5 is joined. Here, the corresponding coil wire 6 and the terminal 12 of the busbar 11 are joined by thermal crimping using electrical resistance, a process called fusing. Each busbar 11 also has a terminal for electrical connection to the motor's control circuit.

[0024] The present invention relates to a method for manufacturing a stator unit 1, but its substantial feature lies in the method of joining the coil wires 6 to the terminals 12 of the busbars 11. Therefore, the method for manufacturing a stator unit 1 will be described in detail below, focusing on the joining process of joining the coil wires 6 to the terminals 12 of the busbars 11. The above joining process includes a temporary fixing step of temporarily fixing each coil wire 6 to the corresponding terminal 12, and a fusing step of fusing the terminals 12 to which the coil wires 6 have been temporarily fixed.

[0025] [Temporary fixing process] In this process, the busbar unit 10 is first positioned relative to the motor stator 2. Specifically, the coaxially arranged Morse stator 2 and the busbar unit 10 are moved relatively closer together, and the three claw portions 14 provided on the busbar unit 10 (or its busbar holder 13) are inserted into the claw receiving portions 8 provided on the insulator 7 of the motor stator 2, corresponding to the claw portions 14. This creates a snap-fit ​​structure that restricts the circumferential movement, axial separation, and radial movement of the busbar unit 10 relative to the motor stator 2 (see Figure 2).

[0026] Furthermore, when the busbar unit 10 is moved closer to the motor stator 2, the three protrusions 15 provided on the busbar holder 13 are fitted into the three receiving parts 9 provided on the insulator 7, respectively, to form a recessed-concave fitting structure (see Figure 2). As a result, the motor stator 2 and the busbar unit 10 engage in the axial, circumferential, and radial directions. Thus, the busbar unit 10 is positioned relative to the motor stator 2 in the axial, circumferential, and radial directions.

[0027] As shown in Figure 1, the coil wire 6 to be joined to the terminal 12 of the busbar 11 protrudes axially outward from the stator core 3 and extends along the axial direction. On the other hand, as shown in Figures 1 and 3(a), the terminal 12 of the busbar 11 (the terminal 12 before the coil wire 6 is temporarily fixed) is formed in a substantially V-shape in cross-section, integrally having an arc portion 12a, a first straight portion 12b, and a second straight portion 12c that is angled with respect to the first straight portion 12b and positioned radially outward from the first straight portion 12b, and is positioned on the extension line of the coil wire 6 to be joined. The inner diameter surface of the arc portion 12a of the terminal 12 is the surface to which the coil wire 6 will be joined during fusing (joining surface S), and the arc portion 12a is formed such that the diameter D1 of its inscribed circle [see Figure 3(b)] is larger than the wire diameter D of the coil wire 6. Therefore, when the busbar unit 10 is positioned relative to the motor stator 2 in the manner described above, each coil wire 6 is inserted into the inside of the terminal 12 (coil insertion portion) with its outer surface (part of it) facing the intended joining surface S of the corresponding terminal 12.

[0028] Note that the coil wire 6 protruding outward in the axial direction of the stator core 3 does not necessarily extend along the axial direction and may be inclined with respect to the axial direction. At this time, if the inclination angle of the coil wire 6 is θ (see FIG. 5), the separation distance between the attachment root portion of the coil wire 6 (the end face 3a of the stator core 3) and the end portion on the side away from the stator core 3 of the terminal 12 of the bus bar 11 is X (see FIG. 5), and the width dimension of the coil insertion portion defined in the terminal 12 is Y (see FIG. 3(a)), it is preferable to use a terminal 12 that satisfies the relational expression of X × tan θ < Y as the terminal 12. Thereby, the work of temporarily fixing the coil wire 6 to the terminal 12 can be easily performed.

[0029] When the coil wire 6 is inserted into the inside (coil insertion portion) of the corresponding terminal 12 in the above aspect, the terminal 12 is deformed to temporarily fix the coil wire 6. Specifically, as shown in FIG. 3(b), it is deformed into a terminal 12 composed of an arc portion 12a and a first sealing portion 12d and a second sealing portion 12e that cooperate with the other side to seal the opening of the arc portion 12a. Here, among the terminals 12 having a substantially V-shaped cross section shown in FIG. 3(a), substantially only the second straight portion 12c is bent (bent and deformed) to obtain the terminal 12 having the shape shown in FIG. 3(b). Therefore, in the terminal 12 in which the coil wire 6 shown in FIG. 3(b) is temporarily fixed, the first sealing portion 12d is composed of the first straight portion 12b, and the second sealing portion 12e has a straight portion parallel to the first sealing portion 12d (the first straight portion 12b). Note that the opposing two surfaces of the first sealing portion 12d and the second sealing portion 12e may be in contact with each other, or may be opposed to each other through a gap.

[0030] The temporary fixing of the coil wire 6, which is performed by deforming the terminal 12 shown in Figure 3(a) into the terminal 12 shown in Figure 3(b), can be carried out using a mold device 20 conceptually shown in Figures 4(a) to (c). The mold device 20 in the illustrated example comprises a stationary mold 21 positioned radially inward of the terminal 12 and a movable mold 22 positioned radially outward of the terminal 12 and moving toward and away from the stationary mold 21. The stationary mold 21 is formed in an L-shape in cross-section, having a first support portion 21a that supports the arc portion 12a of the terminal 12 when the mold is clamped, and a second support portion 21b that extends in a direction perpendicular to the first support portion 21a and supports the first straight portion 12b of the terminal 12 when the mold is clamped. The movable mold 22 is provided with a mold portion 23 with a shape corresponding to the shape of the second sealing portion 12e in order to deform (form) the second straight portion 12c shown in Figure 3(a) into the second sealing portion 12e shown in Figure 3(b).

[0031] Then, as shown in Figure 4(a), after positioning the terminal 12 with the coil wire 6 inserted between the stationary mold 21 and the movable mold 22, as shown in Figures 4(b) and 4(c), when the movable mold 22 is moved closer to the stationary mold 21 and the mold is clamped, the second straight portion 12c of the terminal 12 deforms to conform to the mold portion 23. After holding the clamped state for a predetermined time, when the movable mold 22 is moved away from the stationary mold 21 and the mold is opened, as shown in Figure 3(b), a terminal 12 is obtained in which the coil wire 6 is temporarily fixed with its outer surface facing the intended joining surface S.

[0032] The temporary fixing procedure for the coil wire 6 described above may be performed individually for each terminal 12, or it may be performed on multiple terminals 12 at once.

[0033] [Fusing process] In the fusing process, the coil wire 6 is temporarily fixed to the terminal 12 and then fused. Specifically, as shown in Figure 6, electrodes 31 and 32, which are positioned radially inward and radially outward of the terminal 12 respectively, are moved relatively closer together (in the illustrated example, electrode 32, which is positioned radially outward, is moved radially inward), thereby compressing the terminal 12 in the radial direction of the coil wire 6 while current is passed between the two electrodes 31 and 32 for a predetermined time. As a result, the insulating coating on the coil wire 6, which is made of insulating conductor wire, is removed, and the conductor wire of the coil wire 6 is joined to the terminal 12.

[0034] The fusing of the terminals 12 holding the coil wire 6 may be performed individually for each terminal 12, or it may be performed on multiple terminals 12 at once.

[0035] Through the above process, a stator unit 1 is obtained in which the coil 5 provided on the motor stator 2 and the busbar 11 provided on the busbar unit 10 are electrically connected, and the motor stator 2 and the busbar unit 10 are mechanically connected.

[0036] According to the manufacturing method of the stator unit 1 of the present invention described above, the shape of the terminal 12 of the busbar 11 that holds the coil wire 6 is significantly simplified compared to the terminal shape of the busbar described in Patent Document 1. Furthermore, since the coil wire 6 is temporarily fixed to the terminal 12 at the same time that the terminal 12 of a predetermined shape [the terminal 12 shown in Figure 3(b). That is, the terminal 12 consisting of an arc portion 12a, a first sealing portion 12d, and a second sealing portion 12e] is formed in the temporary fixing process, the work required to perform fusing can be carried out efficiently and accurately.

[0037] Furthermore, in the terminal 12 [see Figure 3(b)], which consists of an arc portion 12a, a first sealing portion 12d, and a second sealing portion 12e formed during the temporary fixing process, the diameter D1 of the inscribed circle of the arc portion 12a, whose inner diameter surface constitutes the planned joining surface S of the coil wire 6, is made larger than the wire diameter D of the coil wire 6. As a result, when fusing is performed on the terminal 12 to which the coil wire 6 has been temporarily fixed, the coil wire 6 can be properly brought into contact with the inner diameter surface (planned joining surface S) of the arc portion 12a. This makes it possible to stably secure the required bonding strength between the coil wire 6 and the terminal 12 of the busbar 11.

[0038] Furthermore, since the first sealing portion 12d and the second sealing portion 12e formed on the terminal 12 for temporarily fixing the coil wire 6 have parallel straight sections, the coil wire 6 temporarily fixed to the terminal 12 is less likely to come off the terminal 12. Therefore, fusing can be performed appropriately and with high precision.

[0039] Furthermore, in this embodiment, with the busbar unit 10 positioned axially, circumferentially, and radially relative to the motor stator 2, a temporary fixing step is performed in which each coil wire 6 is temporarily fixed to the terminal 12 of the corresponding busbar 11, and a fusing step is performed in which fusing is applied to the terminal 12 to which the coil wire 6 has been temporarily fixed. As a result, each coil wire 6 can be joined to the terminal 12 of the corresponding busbar 11 with high precision.

[0040] The combined effects described above make it possible to efficiently, accurately, and firmly connect the coil wire 6 of the coil 5 provided on the motor stator 2 to the terminal 12 of the busbar 11 according to the present invention. As a result, a stator unit 1 with high durability and reliability can be manufactured efficiently.

[0041] The method for manufacturing the stator unit 1 described above can be modified as appropriate without departing from the spirit of the present invention.

[0042] For example, the temporary fixing step of temporarily fixing the coil wire 6 to the corresponding terminal 12 may be carried out using a mold device 20 in which a movable mold 22 is positioned radially inside the terminal 12 and a stationary mold 21 is positioned radially outside the terminal 12. The type of mold device 20 used can be appropriately selected according to the shape of the terminal 12, etc. Therefore, the shape of the terminal 12 to which the coil wire 6 is temporarily fixed is not limited to those described above.

[0043] The stator unit 1 described above can be used, for example, as the stator of the motor section of an electric pump (electric oil pump). Below, a specific example of an electric pump in which the stator unit 1 is used will be briefly described based on Figure 7.

[0044] The electric pump 100 shown in Figure 7 is, for example, mounted on the transmission case of a vehicle and used to ensure the necessary hydraulic pressure inside the transmission by pressurizing oil to the transmission while the engine is stopped. This electric pump 100 mainly comprises a pump unit 101 that sucks in and discharges (pressurizes) oil, a motor unit 110 that drives the pump unit 101, a circuit board 120, and a housing 130 that houses the pump unit 101, the motor unit 110, and the circuit board 120.

[0045] The pump section 101 in the illustrated example is a trochoidal pump having an inner rotor 102 as a pump rotor and an outer rotor 103 eccentrically positioned relative to the inner rotor 102. Specifically, the inner rotor 102 has multiple external teeth, some of which mesh with some of the multiple internal teeth formed on the outer rotor 103. The outer rotor 103 is rotatably fitted to the inner wall surface of the pump housing chamber 131 formed in the housing 130. With this configuration, the outer rotor 103 rotates in tandem with the rotation of the inner rotor 102. If the number of teeth of the external teeth is n (where n is a positive integer of 2 or more), then the number of teeth of the internal teeth is (n+1).

[0046] The motor unit 110 is housed in the housing 130, arranged in the axial direction (parallel to the axis O) alongside the pump unit 101. The motor unit 110 is an electric motor (3-phase brushless motor) having a motor stator 2 (see also Figures 1 and 2) fixed to the inner circumference of a motor housing chamber 132 formed in the housing 130 (housing body 130A), and a motor rotor 111 arranged opposite to the motor stator 2 with a gap between them on the radially inner side of the motor stator 2, and a busbar unit 10 arranged in the axial direction alongside the motor stator 2 on the axially outer side (opposite the pump unit side) of the motor stator 2.

[0047] The motor unit 110 has an output shaft 112 to which a motor rotor 111 is coupled on its outer circumference. The output shaft 112 is longer in the axial direction than the motor rotor 111 and protrudes from both sides of the motor rotor 111 in the axial direction. The output shaft 112 is rotatably supported relative to the housing 130 via two bearings (deep groove ball bearings in the illustrated example) 113A and 113B which are spaced apart in the axial direction.

[0048] An inner rotor 102 is fixed to the pump-side end of the output shaft 112. No gearbox is positioned between the output shaft 112 and the pump section 101. A seal 114 is positioned between the inner rotor 102 and the bearing 113A, and this seal 114 prevents oil interposed in the pump section 101 (pump housing chamber 131) from flowing into the motor section 110 (motor housing chamber 132). In addition, an axially compressed elastic member 115 is positioned between the bearing 113A and the seal 114 to apply axial preload to the bearing 113A (suppressing tilting of the output shaft 112).

[0049] Although detailed illustrations are omitted, the substrate 120 is formed in a roughly rectangular shape in plan view, and its mounting surface 121, on which multiple electronic components 122 are mounted, is arranged along the axis O of the motor unit 110 and the tangential direction of the circle centered on this axis O, and is housed in the substrate housing chamber 133 provided in the housing 130 (housing body 130A) with its mounting surface 121 facing the inner bottom surface of the substrate housing chamber 133. The multiple electronic components 122 are electrically connected to form a control circuit that controls the motor unit 110.

[0050] Power is supplied to the circuit board 120 (and its control circuit) from an external power supply (not shown) via a connector 123. The control circuit of the circuit board 120 controls the polarity of the drive current. The controlled current is supplied to the coil 5 of the motor stator 2 via a busbar 11, the other end of which is electrically connected to the circuit board 120 in the longitudinal direction.

[0051] The housing 130 comprises a housing body 130A having a pump housing chamber 131 for housing the pump unit 101, a motor housing chamber 132 for housing the motor unit 110, and a substrate housing chamber 133 for housing the substrate 120; a first lid 134 that closes the opening of the pump housing chamber 131; a second lid 135 that closes the opening of the motor housing chamber 132; and a third lid 136 that closes the opening of the substrate housing chamber 133. The first lid 134, the second lid 135, and the third lid 136 are each fixed to the housing body 130A using fastening members such as bolts and screws. The housing body 130A, the first lid 134, the second lid 135, and the third lid 136 are all made of a metal material that is electrically conductive and has good thermal conductivity, such as an aluminum alloy.

[0052] As shown in Figures 8(a) and 8(b), the housing 130 (housing body 130A) is provided with holes 139 for fixing the busbar unit 10 to the housing body 130A using fastening members 140 such as bolts. In this case, the fastening members 140 are inserted through holes 16 (see Figure 2) provided in the busbar unit 10 (the busbar holder 13). By fixing the busbar unit 10 to the housing 130 (housing body 130A) using fastening members 140 in this way, the positional accuracy of the busbar unit 10 relative to the housing 130 can be stabilized. In this embodiment, since the other end in the longitudinal direction of the busbar 11 held by the busbar unit 10 is electrically connected to the substrate 120 (control circuit) housed in the housing 130, stabilizing the positional accuracy of the busbar unit 10 is useful for properly constructing the power supply circuit to the motor unit 110.

[0053] The second cover portion 135 consists of a bearing case 135a on which the outer ring of the bearing 113B is mounted on its inner circumference, and a motor cover 135b that closes the opening of the bearing case 135a on the side opposite the pump portion.

[0054] The housing body 130A is provided with oil passages consisting of a suction passage 137 and a discharge passage 138, which are provided separately from each other. By providing both the suction passage 137 and the discharge passage 137 in the housing body 130A, and in conjunction with the fact that the housing body 130A is made of a metal material with good thermal conductivity such as an aluminum alloy, the housing body 130A can be efficiently cooled by the oil flowing through both passages 137 and 138. This cooling effect promotes the cooling of the motor section 110 and the circuit board 120, which are heat-generating components, thereby realizing a highly reliable electric pump 100.

[0055] In the electric pump 100 having the above configuration, when power is supplied to the motor section 110 and the output shaft 112 rotates, the inner rotor 102 of the pump section 101, which is fixed to the output shaft 112, rotates integrally. As the inner rotor 102 rotates, the outer rotor 103, which is meshed with it, rotates in response, and the volume of the space formed between the teeth of both rotors 102 and 103 expands and contracts as both rotors 102 and 103 rotate. Accordingly, oil stored inside the transmission case (not shown) is drawn into the pump section 101 (pump housing chamber 131) via the intake-side passage 137, and the drawn-in oil is discharged (pressurized) into the transmission via the discharge-side passage 138.

[0056] The present invention is not limited in any way to the embodiments described above, and it goes without saying that it can be implemented in various other forms without departing from the spirit of the invention. The scope of the present invention is indicated by the claims, and further includes the equivalent meanings set forth in the claims and all modifications within the scope. [Explanation of symbols]

[0057] 1 Stator Unit 2 Motor Stator 3 Stator Core 5 coils 6 Coil wire 7 Insulators 8 Claw receiving part 10 Busbar Units 11 Bus Bar 12 terminals 12a Arc section 12d 1st sealing part 12e 2nd sealing section 14. Claw part 21 Stationary type 22 Movable type 31 electrode 32 electrodes 100 Electric Pumps S Planned joining surface

Claims

1. A method for manufacturing a stator unit, comprising: a temporary fixing step of temporarily fixing the coil wires of a coil provided on a motor stator to the terminals of a busbar; and a fusing step of joining the coil wires to the terminals by fusing the terminals to which the coil wires have been temporarily fixed, In the temporary fixing step, with the outer surface of the coil wire protruding axially outward from the motor stator positioned opposite the intended joining surface of the terminal, the coil wire is temporarily fixed to the terminal by forming an arc portion on the terminal, where the diameter of the inscribed circle is larger than the diameter of the coil wire and the inner diameter surface constitutes the intended joining surface, and first and second sealing portions that cooperate with the other side to seal the opening of the arc portion. A stationary type is positioned on either the radially outer or radially inner side of the terminal, which has a V-shaped cross-section before the coil wire is temporarily fixed, and integrally comprises the aforementioned arc portion, a first straight portion, and a second straight portion that is angled with respect to the first straight portion and connected to the first straight portion via the arc portion. A method for manufacturing a stator unit, characterized in that, with respect to the stationary mold in which the first support portion supports the arc portion and the second support portion supports the first straight portion, a movable mold having a mold portion corresponding to the second sealing portion is moved closer to the stationary mold in such a way that the distance between the surface of the first support portion that supports the arc portion and the surface of the second support portion that supports the first straight portion becomes small, and the mold is clamped, thereby deforming the second straight portion to conform to the mold portion, and thereby obtaining the terminal consisting of the arc portion, the first sealing portion and the second sealing portion.

2. The method for manufacturing a stator unit according to claim 1, wherein the first sealing portion and the second sealing portion have parallel linear portions.

3. A method for manufacturing a stator unit according to claim 1 or 2, wherein the temporary fixing step and the fusing step are performed while the relative movement of the motor stator and the busbar unit holding the busbar is restricted.

4. A method for manufacturing a stator unit according to claim 3, wherein the relative movement of the busbar unit with respect to the motor stator is restricted by a snap-fit ​​structure in which a claw portion provided on either the busbar unit or the motor stator is fitted into a claw receiving portion provided on the other.

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