Drive device

Abstract

A drive device (1) comprises a motor (10) and a controller (50). The motor (10) has: a motor housing (15, 150); a stator (12) that is fixed to the motor housing (15, 150); a motor wire (11) that is wound around the stator; a rotor (13) that rotates by means of energization of the motor wire (11); and a shaft (14) that rotates integrally with the rotor (13). The motor housing (15, 150) has a cylindrical motor case (16). The controller (50) has: a substrate (53), on which electronic components (54, 55) relating to drive control of the motor (10) are mounted; and a controller housing (601-610) that accommodates the substrate (53). The controller is fixed to one side in the axial direction of the motor case (16). At least a part of the electronic components (54, 55) is sealed in a state of being embedded in the controller housing (601).

Description

Drive unit CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on Patent Application No. 2023-116747, filed on July 18, 2023, the contents of which are incorporated herein by reference.

[0002] The present disclosure relates to a drive device.

[0003] Conventionally, there has been known an electromechanical integrated motor in which a control device is integrally formed on one side of the motor in the axial direction. For example, in Patent Document 1, a heat sink is fixed to the inside of the motor housing by an interference fit.

[0004] Japanese Patent Application Laid-Open No. 2020-188556

[0005] When heat from a heat-generating element is dissipated to a heat sink, the heat is stored in the heat sink and transferred to the motor case, where it is dissipated into space. In Patent Document 1, the heat sink and motor case, which form the heat dissipation path, are made of metal, which has good thermal conductivity. However, if components that form the heat dissipation path, such as the heat sink, are made of a material other than metal (e.g., resin), there is a risk that the heat dissipation will not keep up with the amount of heat generated. Furthermore, if the heat sink is installed inside the motor case, the heat-generating components can only be placed in a location facing the heat sink. The purpose of the present disclosure is to provide a drive device that can dissipate heat generated by electronic components.

[0006] The drive device of the present disclosure includes a motor and a controller. The motor has a housing with a cylindrical motor case, a stator fixed to the motor housing, motor wires wound around the stator, a rotor that rotates when current is applied to the motor wires, and a shaft that rotates integrally with the rotor.

[0007] The controller has a circuit board on which electronic components related to the drive control of the motor are mounted, and a controller housing that houses the circuit board, and is fixed to one axial side of the motor case. At least a portion of the electronic components are embedded and sealed in the controller housing, which is made of an insulating material. Embedding the electronic components in the controller housing allows heat from the electronic components to be dissipated into the controller housing.

[0008] The above and other objects, features and advantages of the present disclosure will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. 1 is a schematic diagram of a steering system according to the first embodiment, FIG. 2 is a cross-sectional view of a drive unit according to the first embodiment, FIG. 3 is a schematic diagram illustrating the connection between a motor case and an ECU case according to the first embodiment, FIG. 4 is a flowchart illustrating an assembly process of a drive unit according to the first embodiment, FIG. 5 is an explanatory diagram illustrating assembly of a motor case and a stator according to the first embodiment, FIG. 6 is an explanatory diagram illustrating assembly of a rotor ASSY according to the first embodiment, FIG. 7 is an explanatory diagram illustrating assembly of a motor ASSY according to the first embodiment, FIG. 8 is an explanatory diagram illustrating assembly of an ECU case and an ECU-ASSY to a motor ASSY according to the first embodiment, FIG. 9 is a cross-sectional view of a drive unit according to the second embodiment, FIG. 10 is a cross-sectional view of a drive unit according to the third embodiment, FIG. 11 is a cross-sectional view of a drive unit according to the fourth embodiment, and FIG. 14 is an explanatory diagram illustrating the assembly of an ECU case to a motor ASSY according to the fifth embodiment; FIG. 15 is an explanatory diagram illustrating the assembly of an ECU-ASSY to an ECU case according to the fifth embodiment; FIG. 16 is a cross-sectional view of a drive device according to the sixth embodiment; FIG. 17 is a cross-sectional view of a drive device according to the seventh embodiment; FIG. 18 is a cross-sectional view of a drive device according to the eighth embodiment; FIG. 19 is a cross-sectional view of a drive device according to the ninth embodiment; FIG. 20 is a cross-sectional view of a drive device according to the tenth embodiment; FIG. 21 is a flowchart illustrating the assembly process of a drive device according to the tenth embodiment; FIG. 22 is an explanatory diagram illustrating the assembly of a motor ASSY and an ECU-ASSY according to the tenth embodiment; and FIG. 23 is a cross-sectional view of a drive device according to the eleventh embodiment.

[0009] A drive device according to the present disclosure will be described below with reference to the drawings. In the following, substantially identical components in multiple embodiments will be assigned the same reference numerals and descriptions thereof will be omitted.

[0010] (First embodiment) A first embodiment is shown in Figures 1 to 8. As shown in Figure 1, a drive device 1 includes a motor 10 and an ECU 50 as a controller, and is applied to an electric power steering device 8. Figure 1 shows the configuration of a steering system 90 that includes the electric power steering device 8. The steering system 90 includes a steering wheel 91, which is a steering member, a steering shaft 92, a pinion gear 96, a rack shaft 97, wheels 98, the electric power steering device 8, and the like.

[0011] The steering wheel 91 is connected to a steering shaft 92. A torque sensor 94 that detects steering torque is provided on the steering shaft 92. A pinion gear 96 is provided at the tip of the steering shaft 92. The pinion gear 96 meshes with a rack shaft 97. A pair of wheels 98 are connected to both ends of the rack shaft 97 via tie rods or the like.

[0012] When the driver turns the steering wheel 91, the steering shaft 92 connected to the steering wheel 91 rotates. The rotational motion of the steering shaft 92 is converted into linear motion of a rack shaft 97 by a pinion gear 96. A pair of wheels 98 are steered to an angle corresponding to the amount of displacement of the rack shaft 97.

[0013] The electric power steering device 8 includes the drive unit 1 and a reduction gear 89, which is a power transmission unit that reduces the speed of the rotation of the motor 10 and transmits it to the steering shaft 92. That is, the electric power steering device 8 of this embodiment is a so-called "column assist type," and the steering shaft 92 can be said to be the driven object. It may also be a so-called "rack assist type," in which the rotation of the motor 10 is transmitted to a rack shaft 97.

[0014] The motor 10 is, for example, a three-phase brushless motor. The motor 10 outputs part or all of the torque required for steering, is driven by power supplied from a battery (not shown), and rotates the reduction gear 89 forward and reverse. The drive unit 1 has the ECU 50 provided on one axial side of the motor 10, making it a so-called "mechatronically integrated" drive unit. The mechatronically integrated drive unit 1 allows the motor 10 and ECU 50 to be efficiently arranged in vehicles with limited installation space. Hereinafter, the terms "axial direction" and "radial direction" will be used to refer to the axial and radial directions of the motor 10. The lower side of the paper in FIG. 2 and other figures is the output end side.

[0015] As shown in Fig. 2, the motor 10 includes a stator 12, a rotor 13, a shaft 14, and a motor housing 15. The stator 12 is fixed to the motor housing 15, and a motor wire 11 is wound around the stator 12. The motor wire 11 is not shown in any illustration except Fig. 2. The rotor 13 is provided radially inside the stator 12 and is rotatable relative to the stator 12.

[0016] The shaft 14 is fitted into the rotor 13 and rotates integrally with the rotor 13. The shaft 14 is rotatably supported in the motor housing 15 by bearings 141 and 142. The end of the shaft 14 on the ECU 50 side is exposed from the motor housing 15 to the ECU 50 side, and is provided with a sensor magnet 145. The end of the shaft 14 opposite the ECU 50 is an output end, which is provided with a pulley 147 and is connected to the reduction gear 89.

[0017] The motor housing 15 has a motor case 16, a front frame 17, and a rear frame 18. The motor case 16 is formed into a cylindrical shape from aluminum, for example. The motor case 16 has a front frame 17 integrally molded on the output end side and an ECU case 61 (described below) integrally molded on the ECU 50 side. In this specification, the term "integrally molded" or "formed as an integrally molded product" refers to a state in which at least one preformed member A is inserted to form a member B, and members A and B may be made of the same material or different materials.

[0018] The front frame 17 is made of, for example, phenolic resin, and seals the end portion on the output end side of the motor case 16. The front frame 17 is formed with a bearing holder 171, an outer wall abutment portion 172, a flange portion 175, and the like. The bearing holder 171 is provided with a bearing 141.

[0019] The outer wall contact portion 172 is formed in a cylindrical shape along the outer peripheral wall of the motor case 16, extending radially inward toward the ECU 50. The provision of the outer wall contact portion 172 prevents water droplets and the like from entering the inside of the device from the connection point between the motor case 16 and the front frame 17. A plurality of flange portions 175 are formed to protrude radially outward, and are attached to the gearbox with fixing members such as screws (not shown). They may also be attached to a housing other than the gearbox.

[0020] The rear frame 18 is formed into a substantially circular plate shape from, for example, phenolic resin, and is fixed to the ECU 50 side of the motor case 16. A bearing 142 is fixed to the rear frame 18. The frames 17 and 18 hold the bearings 141 and 142, and can also be considered as bearing holding members.

[0021] The ECU 50 includes a circuit board 53, a connector 57, and an ECU housing 601. The circuit board 53 extends radially outward beyond the motor area, which is the area of ​​the motor case 16 projected in the axial direction, and is fixed to the ECU housing 601 by a fixing member 59 such as a tapping screw. Fixing members other than tapping screws may be used, and the circuit board 53 may be fixed to the ECU housing 601 by, for example, resin caulking. Hereinafter, the surface of the circuit board 53 facing the motor 10 will be referred to as a motor surface 531, and the surface opposite the motor 10 will be referred to as a cover surface 532.

[0022] Lead wires 115 taken out from each phase of the motor wire 11 are formed to extend toward the ECU 50 and are electrically connected to the substrate 53 within the motor area. In this embodiment, the lead wires 115 are soldered to the substrate 53, but the connection method is not limited to soldering as long as an electrical connection is established, and a solderless connection such as an elastic connection by press-fit or a mating connection using a socket connector may also be used.

[0023] Various electronic components such as a heating element 54, a capacitor 55, and a rotation angle sensor 56 are mounted on the substrate 53. In this embodiment, the heating element 54 and the capacitor 55 are mounted on a cover surface 532 of the substrate 53. The heating element 54 includes a switching element that constitutes an inverter that switches the current flow to the motor wires 11, a motor relay, a power relay, etc. The rotation angle sensor 56 is mounted on the motor surface 531 at a location facing the sensor magnet 145, and detects the rotation of the motor 10 by detecting the rotating magnetic field of the sensor magnet 145. Note that the rotation angle sensor 56 is not shown in the assembly description.

[0024] Connector 57 is provided outside the motor area on the motor surface 531 side of substrate 53, and connector terminals 571 are connected to substrate 53. A flange 575 extending from the main body toward the outer periphery is formed on the end of connector 57 on the substrate 53 side. Flange 575 is formed in an L-shape in cross section, with the tip protruding toward the opposite side from substrate 53.

[0025] The ECU housing 601 has an ECU case 61 and an ECU cover 71, and is formed so that a portion of the ECU case 61 extends radially outward from the motor area. The ECU case 61 is made of, for example, epoxy resin and has a generally cylindrical shape with a bottom that opens on the side opposite the motor 10. The ECU case 61 is molded integrally with the motor case 16 and seals the end of the motor case 16 on the ECU 50 side.

[0026] As shown in Figure 3, the motor case 16 is formed with sealing holes 162 that penetrate the plate thickness direction. A plurality of sealing holes 162 are formed spaced apart in the circumferential direction at the location integrally molded with the ECU case 61. When the motor case 16 and the ECU case 61 are integrally molded, the ECU case 61 is formed by sandwiching the radially inner and outer sides of the motor case 16 at the end of the motor case 16 on the ECU 50 side. Here, the resin of the ECU case 61 enters the sealing holes 162, thereby improving the joint strength.

[0027] Similarly, a plurality of sealing holes 163 penetrating in the thickness direction are formed at intervals in the circumferential direction at the portion of the motor case 16 that is integrally molded with the front frame 17. When the motor case 16 and the front frame 17 are integrally molded, the resin of the front frame 17 enters the sealing holes 163, thereby improving the joining strength.

[0028] Returning to FIG. 2, the ECU case 61 is formed with an outer wall abutment portion 611, a through hole 612, a board holding portion 613, a connector mounting portion 614, and a connector insertion hole 615 (see FIG. 8).

[0029] The outer wall abutment portion 611 is formed in a cylindrical shape along the outer peripheral wall of the motor case 16, extending radially inward toward the output end. Providing the outer wall abutment portion 611 prevents water droplets and the like from entering the inside of the device through the connection between the motor case 16 and the ECU case 61. Note that the outer wall abutment portion 611 may not be provided, and the axial length of the radially outer portion of the motor case 16 at the connection between the motor case 16 and the ECU case 61 may be equal to or shorter than the axial length of the radially inner portion. The same applies to the outer wall abutment portion 172 of the front frame 17. Furthermore, the illustration of the outer wall abutment portion 611 has been omitted as appropriate except in Figure 2.

[0030] The through-hole 612 is provided so as to penetrate in the axial direction at a position corresponding to the shaft 14, and a sensor magnet 145 is disposed inside the through-hole 612. The board holding portion 613 is formed in the motor area, and the board 53 is fixed thereto by a fixing member 59. The connector 57 is attached to the connector attachment portion 614 with an adhesive or the like. In detail, the main body of the connector 57 is inserted into the connector insertion hole 615 with the opening exposed to the outside, and then the flange portion 575 is inserted into the connector attachment portion 614 to which the adhesive or the like has been applied, thereby attaching the connector 57 to the ECU case 61.

[0031] The ECU cover 71 is made of, for example, epoxy resin, and is provided on the cover surface 532 side of the substrate 53. The ECU cover 71 is integrally molded with the ECU case 61, and resin-seals the substrate 53, as well as the heating elements 54 and capacitors 55 mounted on the cover surface 532 side of the substrate 53. The ECU cover 71 is formed with heat dissipation fins 711 in an element mounting area, which is an axial projection of the area where the heating elements 54 are mounted.

[0032] The assembly process of the drive unit 1 of this embodiment will be described with reference to the flowchart of Fig. 4 and Fig. 5 to Fig. 8. Hereinafter, the "step" such as step S10 will be omitted and simply referred to as the symbol "S".

[0033] As shown in Fig. 5, in S10, the front frame 17 is integrally molded with the motor case 16. In S11, the stator 12 is shrink-fitted to the motor case 16. As shown in Fig. 6, in S12, the bearing 142 is fixed to the rear frame 18 by caulking, press-fitting, or the like. In S13, the bearings 141 and 142 are press-fitted into the rotor assembly in which the shaft 14 is press-fitted into the rotor 13. Note that S10, S11, and S12, S13 may be reversed in order or may be performed in parallel.

[0034] As shown in Figure 7, in S14, the rotor assembly shown on the right side of Figure 6 is assembled to the motor case 16 shown on the right side of Figure 5. Specifically, the rear frame 18 is shrink-fitted to the motor case 16. The bearing 141 is inserted into the bearing holder 171 of the front frame 17. In S15, a pulley 147 is press-fitted into the end of the shaft 14 on the output end side, and a sensor magnet 145 is press-fitted into the end of the shaft 14 on the ECU 50 side. Hereinafter, the state in which the stator 12, front frame 17, rear frame 18, etc. are assembled to the motor case 16 will be referred to as the motor assembly.

[0035] 8, in S16, the ECU case 61 is resin-molded integrally with the motor case 16 in the state of the motor assembly (see the left side of FIG. 8). In S17, adhesive is applied to the connector mounting portion 614 of the ECU case 61. In S18, the ECU-ASSY with the connector 57 attached is attached to the ECU case 61 (see the right side of FIG. 8).

[0036] In S19, the lead wires 115 are electrically connected to the substrate 53. If the connection between the lead wires 115 and the substrate 53 is a solderless connection such as a press-fit connection, the connection is completed when the ECU-ASSY is assembled to the ECU case 61 in S18, and S19 is therefore omitted. In S20, the ECU-ASSY is sealed with resin to form the ECU cover 71 (see FIG. 2). In the figure, the rotor ASSY is designated as "RA," the motor ASSY as "MA," and the ECU-ASSY as "EA" as appropriate.

[0037] For example, as a comparative example, if the rear frame is made of a metal heat sink and the heat from the heating element 54 is dissipated to the motor case 16 side, the heating element 54 needs to be mounted on the motor surface 531 side of the substrate 53 and within the motor area.

[0038] In contrast, in the drive unit 1 of this embodiment, the heating element 54 is embedded in resin in the ECU cover 71, and heat is dissipated by air radiation through the ECU cover 71, with which the heating element 54 is in direct contact. This makes it possible to mount the heating element 54 on the cover surface 532 side or outside the motor area, improving the flexibility of board design. In addition, there is no need for an intervening material such as heat dissipation gel, which is required when dissipating heat using a metal heat sink.

[0039] The ECU case 61 is molded integrally with the motor case 16 using resin insert molding, sealing the ends of the motor case 16. The front frame 17 is molded integrally with the motor case 16 using resin insert molding, sealing the ends of the motor case 16. This allows for a simple configuration that prevents water droplets, dust, and other contaminants from entering the device without any crevice corrosion. Furthermore, the ECU case 61 and front frame 17 are connected to the motor case 16 without the use of adhesive or other sealing material, eliminating gaps caused by deterioration of the sealing material over time and maintaining waterproof performance over time. It is desirable for the ECU case 61, front frame 17, and motor case 16, which are molded integrally, to be made of materials with similar linear expansion coefficients.

[0040] In this embodiment, the motor case 16 is formed from metal, and the front frame 17 is formed from resin. In other words, in this embodiment, instead of forming the motor case as a cylindrical, bottomed cylinder with the cylindrical portion and the side opposite the ECU 50 as a single component, the cylindrical motor case 16 and the approximately disk-shaped front frame 17 are separated, and the end of the metal motor case 16 is molded with resin to form the front frame 17, thereby forming the motor case 16 and the front frame 17 as a single, integrally molded component. This allows the components to be separated without compromising corrosion resistance. Furthermore, since the front frame 17 is relatively easy to form by forming it as a separate component from the motor case 16, it is possible to use a material that is highly corrosion-resistant and has relatively low fluidity.

[0041] As described above, the drive device 1 includes the motor 10 and the ECU 50. The motor 10 includes a motor housing 15 having a cylindrical motor case 16, a stator 12 fixed to the motor housing 15, motor wires 11 wound around the stator, a rotor 13 that rotates when current is applied to the motor wires 11, and a shaft 14 that is rotatably supported by the motor housing 15 and rotates integrally with the rotor 13.

[0042] The ECU 50 has a board 53 on which electronic components related to the drive control of the motor 10 are mounted, and an ECU housing 601 that houses the board 53, and is fixed to one axial side of the motor case 16. The electronic components include a heat generating element 54 and a capacitor 55. At least a portion of the electronic components are embedded and sealed in the ECU housing 601, which is made of an insulating material.

[0043] In this embodiment, by using a structure in which the electronic components are embedded in the ECU housing 601 with resin, heat generated by the passage of current through the electronic components can be dissipated from the ECU housing 601. Furthermore, by dissipating heat from the ECU housing 601, components that require heat dissipation can be arranged outside the motor area, which provides greater freedom in board design compared to dissipating heat to the motor side, such as the rear frame 18. Furthermore, by forming the ECU housing 601 from an insulating material such as resin, there is no need for an intervening material such as heat dissipating gel, which is required when dissipating heat to a heat sink or the like made of a metal material.

[0044] The ECU housing 601 has an ECU case 61 fixed to the motor case 16, and an ECU cover 71 that seals the electronic components mounted on a cover surface 532, which is the surface of the circuit board 53 opposite the motor 10. This allows heat from the electronic components mounted on the cover surface 532 to be dissipated to the ECU cover 71.

[0045] The ECU case 61 seals the end of the motor case 16 on the ECU 50 side. In this embodiment, the ECU case 61 sandwiches the radially inner and outer sides of the motor case 16 and is molded integrally with the motor case 16. This allows the ECU 50 to be assembled to the motor case 16 without using adhesive or the like, thereby preventing water droplets and foreign matter from entering the device from the connection point between the motor 10 and the ECU 50.

[0046] The electronic components include a heat generating element 54 that generates heat when energized. Heat dissipation fins 711 are formed on the ECU cover 71 of the ECU housing 601 at locations where the heat generating element 54 is projected in the axial direction. This makes it possible to improve the heat dissipation efficiency of the heat generating element 54.

[0047] Second Embodiment A second embodiment is shown in Figure 9. The second to eleventh embodiments differ from the above-described embodiments mainly in the ECU housing, and this point will be mainly described. The ECU housing 602 according to the second embodiment has an ECU case 62 and an ECU cover 71. The ECU case 62 is formed with heat dissipation fins 621.

[0048] In this embodiment, the heating element 54 is mounted on the motor surface 531 and the cover surface 532. When appropriately distinguishing between the mounting surfaces below, the heating element mounted on the motor surface 531 will be referred to as the motor-side element 541, and the heating element mounted on the cover surface 532 will be referred to as the cover-side element 542. The motor-side element 541 abuts against the ECU case 62 and dissipates heat toward the ECU case 62. A heat-dissipating gel or the like may be provided between the motor-side element 541 and the ECU case 62.

[0049] The motor-side element 541 is mounted outside the motor area of ​​the substrate 53. The heat dissipation fins 621 are formed in the element mounting area where the motor-side element 541 is mounted. By arranging the motor-side element 541 outside the motor area, a configuration for improving the heat dissipation efficiency of the heat dissipation fins 621 and the like can be provided in the ECU case 62 without interfering with the motor case 16. This also provides the same effects as the above embodiment.

[0050] (Third embodiment) A third embodiment is shown in Fig. 10. An ECU housing 603 of this embodiment has an ECU case 63 and an ECU cover 72. The ECU case 63 is integrally molded with the motor case 16 so as to fit generally within the motor area. Although the outer wall abutment portion is omitted in Fig. 10, an outer wall abutment portion may be provided. This also applies to the embodiments described below.

[0051] The ECU cover 72 extends radially outward from the motor area and integrally seals both sides of the substrate 53 with resin. On the motor surface 531 side, the ECU cover 72 seals the area radially outward from the through-hole 612 of the ECU case 63. That is, the rotation angle sensor 56 mounted inside the through-hole 612 of the motor surface 531 is not sealed in the ECU cover 72, but faces the sensor magnet 145 in an exposed state. The ECU cover 72 has heat dissipation fins 721 and 722 formed in the element mounting area where the heat-generating element 54 is mounted.

[0052] In this embodiment, the ECU case 63 is molded integrally with the motor ASSY (S16 in FIG. 4), the ECU-ASSY with the connector 57 assembled thereto is assembled to the ECU case 63 (S18), and the board 53 and the lead wires 115 are electrically connected (S19). Then, the motor surface 531 side and the cover surface 532 side of the board 53 are sealed with resin to form the ECU cover 72 (S20).

[0053] The ECU cover 72 of this embodiment not only seals the elements mounted on the cover surface 532 side of the circuit board 53, but also the connector 57 and motor-side elements 541 provided on the motor surface 531 side. This allows the motor-side elements 541 to be embedded in the ECU cover 72 with resin, allowing heat to be dissipated to the ECU cover 72. In addition, the step (S17) of connecting the connector 57 and the ECU case with adhesive is unnecessary. If the connector 57 is molded integrally with the ECU housing, the flange 575 may be omitted.

[0054] The ECU case 63 has a through hole 612 in which the end of the shaft 14 on the ECU 50 side is disposed. The ECU cover 72 seals the electronic components mounted outside the through hole 612 on the motor surface 531, which is the surface on the motor side of the circuit board 53. This allows the electronic components mounted on the motor surface 531 to be embedded in resin in the ECU cover 72 and dissipate heat. This also provides the same effects as the above embodiment.

[0055] 11 and 12 show a fourth embodiment. The ECU housing 604 of this embodiment is formed by integrally sealing both surfaces of the motor case 16 and the circuit board 53 with resin. In other words, the ECU housing 604 of this embodiment can be considered to be a single component that combines the ECU case and ECU cover of the above-described embodiments. The ECU housing 604 has a sensor magnet 145 disposed therein and an opening 618 that opens toward the motor 10. The rotation angle sensor 56 is mounted on the motor surface 531 of the circuit board 53, exposed through the opening 618 and facing the sensor magnet 145.

[0056] The motor housing 150 has a motor case 16, a front frame 17, and a rear frame 19. The rear frame 19 is formed with a plurality of board holding portions 191 that protrude toward the ECU 50. The boards 53 are fixed to the board holding portions 191 by fixing members 59, resin caulking, or the like.

[0057] The assembly process of this embodiment will be described with reference to the flowchart in Figure 12. The assembly of the motor assembly in S10 to S15 is the same as in Figure 4. In S21, which follows S15, the circuit board 53 is attached to the circuit board holder 191, and the ECU-ASSY is assembled to the motor ASSY. In S22, similar to S19 in Figure 4, the circuit board 53 and the lead wires 115 are electrically connected. In S23, the motor case 16 and the ECU-ASSY are integrally sealed with resin to form the ECU housing 604.

[0058] In this embodiment, the motor housing 150 is fixed to the motor case 16 on the ECU 50 side of the stator 12, and has a rear frame 19 formed with a board holder 191 that protrudes toward the ECU 50 and holds the board 53. The ECU housing 604 integrally seals the end of the motor case 16 on the ECU 50 side and both sides of the board 53. This reduces the number of parts. It also reduces the number of locations that require bonding using adhesives or the like. The same effects as the above-described embodiment are also achieved.

[0059] 13 to 15 and a sixth embodiment are shown in Fig. 16. As shown in Fig. 13, in the fifth embodiment, an ECU housing 605 has an ECU case 64 and an ECU cover 73.

[0060] The ECU case 64 has an adhesive groove 641 into which the end of the motor case 16 on the ECU 50 side is inserted, and is formed separately from the motor case 16 using a resin such as PBT. The motor case 16 of this embodiment does not have a sealing hole 162. The ECU case 64 is attached to the motor case 16 with an adhesive applied to the adhesive groove 641. The ECU case 64 is formed to extend outside the motor area, and is provided with heat dissipation fins 621.

[0061] The ECU cover 73 is molded integrally with the ECU case 64, and resin-seals the electronic components mounted on the cover surface 532 of the circuit board 53 and the electronic components mounted outside the through-hole 612 of the motor surface 531. The ECU cover 73 is formed with heat dissipation fins 711.

[0062] 16 , in the sixth embodiment, an ECU housing 606 includes an ECU case 65 and an ECU cover 72. The ECU case 65 is separate from the motor case 16 and is formed generally in the motor area. The ECU case 65 is similar to the ECU case 63 of the third embodiment, except that it is attached to the motor case 16 with an adhesive.

[0063] The assembly process of the drive unit 1 will be described using the fifth embodiment as an example. The assembly flow is the same as that of the first embodiment, except that in assembling the motor ASSY and the ECU case 64 in S16 of Fig. 4, the motor case 16 and the ECU case 64 are fixed with adhesive instead of being integrally molded.

[0064] 14, adhesive is applied to the adhesive groove 641 of the ECU case 64, and the end of the motor case 16 on the ECU 50 side is inserted into the adhesive groove 641. In this way, the ECU case 64 is assembled to the motor assembly.

[0065] 15, adhesive is applied to the connector mounting portion 614 of the ECU case 64, and the ECU-ASSY is assembled to the ECU case 64. Then, after the lead wires 115 and the circuit board 53 are electrically connected, the ECU-ASSY is sealed with resin to form the ECU cover 73 (see FIG. 13).

[0066] By making the ECU cases 64, 65 separate from the motor case 16, the ECU-ASSY can be assembled relatively easily to the motor ASSY. This also simplifies the formation of the ECU cases 64, 65. This also provides the same effects as the above-described embodiment.

[0067] (Seventh and Eighth Embodiments) A seventh embodiment is shown in FIG. 17 , and an eighth embodiment is shown in FIG. 18 . As shown in FIG. 17 , an ECU housing 607 of the seventh embodiment includes an ECU case 62 and an ECU cover 74. The ECU cover 74 is substantially similar to the ECU cover 71 of the first embodiment, except that it does not have heat dissipation fins. A cover member 741 is attached to the element mounting area of ​​the ECU cover 74 on the side opposite the motor 10, where the heat-generating elements 54 are mounted. In this embodiment, the cover member 741 is attached with an adhesive or the like after the ECU cover 74 is integrally molded with the ECU case 62. Alternatively, as in the eighth embodiment shown in FIG. 18 , a plate-shaped cover member 742 may be insert-molded into the ECU cover 74 in the element mounting area.

[0068] The cover members 741 and 742 are made of a metal such as an iron plate having good thermal conductivity, but may also be made of resin. The provision of the cover members 741 and 742 improves the heat dissipation efficiency of the heating element 54. The cover members 741 and 742 also function as reinforcement for the ECU cover 74.

[0069] In this embodiment, cover members 741 and 742 are provided on the ECU cover 74 of the ECU housing 607 at locations where the electronic components are projected in the axial direction. This protects the electronic components from external forces. Furthermore, by forming the cover members 741 and 742 from a material with good thermal conductivity, a thermal mass is added, improving heat dissipation efficiency. This also provides the same effects as the above-described embodiment.

[0070] Ninth Embodiment A ninth embodiment is shown in FIG. 19. As shown in FIG. 19, an ECU housing 608 has an ECU case 62 and an ECU cover 75. A flow path 751 through which a fluid such as coolant can flow is formed in the ECU cover 75 at a location where the heating element 54 is projected in the axial direction. This improves the heat dissipation efficiency of the heating element 54. This also achieves the same effects as the above embodiments. Note that the cover members 741, 742 and the flow path 751 of the seventh to ninth embodiments may be provided in the ECU housing of any of the embodiments.

[0071] Tenth Embodiment A tenth embodiment is shown in Figures 20 to 22. As shown in Figure 20, an ECU housing 609 has an ECU case 66 and an ECU cover 76. An adhesive groove 641 is formed in the ECU case 66, and the ECU case 66 is fixed to the motor case 16 with an adhesive. A lead wire insertion hole 661 is formed in the ECU case 66.

[0072] The ECU cover 76 is molded integrally with the ECU case 66. A communication hole 761 is formed in the ECU cover 76, which connects the connection portion between the lead wire 115 and the substrate 53 with the outside. A jig used to connect the substrate 53 and the lead wire 115 can be inserted through the communication hole 761. The opening of the communication hole 761 is sealed with a sealing cover 765. The adhesive portion of the sealing cover 765 is inserted into the adhesive groove 762 and attached to the ECU cover 76 with an adhesive.

[0073] The assembly process for the drive unit 1 of this embodiment will now be described with reference to the flowchart in Figure 21 and Figure 22. As shown on the left side of Figure 22, in S31, the ECU-ASSY is integrally molded. More specifically, the ECU case 66 and the ECU cover 76 are integrally molded, and the motor surface 531 and the cover surface 532 of the circuit board 53 are sealed with resin. In S32, adhesive is applied to the adhesive grooves 641.

[0074] As shown on the right side of Figure 22, in S33, the resin-sealed ECU-ASSY is assembled to the motor ASSY. In other words, in this embodiment, the ECU-ASSY is formed separately from the motor ASSY and then assembled. The motor ASSY assembly process is the same as in the first embodiment, so a description thereof will be omitted.

[0075] In S34, the lead wire 115 is electrically connected to the substrate 53. In this embodiment, since the communication hole 761 is provided, a jig can be inserted through the communication hole and the lead wire 115 can be connected to the substrate 53 by soldering or the like. In S35, the sealing cover 755 is attached to close the opening of the communication hole 761 (see FIG. 20).

[0076] The ECU cover 76 of the ECU housing 609 has a communication hole 761 that connects the connection point between the circuit board 53 and the motor wire 11 with the outside. The opening of the communication hole 761 is sealed with a sealing cover 765. By providing the communication hole 761 in the ECU cover 76, the ECU-ASSY can be assembled to the motor ASSY while being sealed with resin. This makes it relatively easy to seal the ECU-ASSY with resin. In addition, the same effects as those of the above embodiment can be achieved.

[0077] 23 shows an eleventh embodiment. An ECU housing 610 has an ECU case 66 and an ECU cover 77. A terminal relief groove 771 is formed in the ECU cover 77. The terminal relief groove 771 can accommodate the tip of the lead wire 115 and is not open to the outside.

[0078] In this embodiment, the lead wire 115 and the substrate 53 are electrically connected by a solderless connection without using solder. In this embodiment, a press-fit portion 116 is formed at the tip of the lead wire 115, and the lead wire 115 and the substrate 53 are connected by elastic contact. The connection between the lead wire 115 and the substrate 53 is not limited to press-fit, and may be made using, for example, a socket connector, as long as the electrical connection can be made without soldering. In other words, a "solderless connection" that does not use soldering includes a "connection by elastic contact" such as a press-fit connection, and a "connection by fitting" using a socket connector, etc.

[0079] The assembly process is generally the same as in the eleventh embodiment, but in this embodiment, the lead wires 115 and the substrate 53 are press-fit connected, so the electrical connection between the motor assembly and the ECU-ASSY is completed when the resin-sealed ECU-ASSY is assembled to the motor assembly in S33. Also, since there is no need to provide a communication hole and a sealing cover to seal it, the number of parts and the assembly process can be reduced.

[0080] In this embodiment, the motor wires 11 are electrically connected to the circuit board 53 by a solderless connection. A terminal relief groove 771 is formed in the ECU cover 77 of the ECU housing 610 at a location corresponding to the connection between the lead wires 115 and the circuit board 53. By configuring the motor wires 11 and the circuit board 53 to be electrically connectable without soldering, it is possible to omit the soldering process that is performed after assembling the ECU-ASSY to the motor ASSY. This also provides the same effects as the above embodiment.

[0081] In the embodiment, the rear frame 19 corresponds to the "frame member," the ECU 50 corresponds to the "controller," the ECU housings 601 to 610 correspond to the "controller housing," the ECU cases 61 to 66 correspond to the "first housing," the ECU covers 71 to 77 correspond to the "second housing," the heating element 54 and the capacitor 55 correspond to the "electronic component," the heating element 54 corresponds to the "heat-generating component," and the sensor magnet 154 corresponds to the "detected member."

[0082] (Other Embodiments) In the above embodiment, an example was shown in which phenolic resin was used as the material for the front frame and rear frame, and epoxy resin or PBT was used as the material for the controller housing. In other embodiments, the controller housing may be made of a material other than epoxy resin or PBT. Furthermore, the front frame and rear frame may be made of a material other than phenolic resin. For example, to further improve heat dissipation, the rear frame may be made of a metal with good thermal conductivity, such as an aluminum alloy. Furthermore, the motor case may be made of resin instead of aluminum.

[0083] In the above embodiment, the motor case is formed by integrally molding the front frame and the motor case as separate members. In other embodiments, the motor case may be formed into a cylindrical shape with a bottom that opens toward the controller, and the motor case and the front frame may be formed into a single member. As a supplementary note, even if the motor case is formed into a cylindrical shape with a bottom, it is still included in the concept of a "cylindrical motor case."

[0084] In the above embodiment, when the motor case and the controller housing are integrally molded, a sealing hole is formed in the motor case, and the motor case is integrally molded with the controller housing sandwiching the inner and outer sides in the radial direction. In other embodiments, when the motor case and the ECU housing are integrally molded, the motor case does not have to be sandwiched between the inner and outer sides in the radial direction. Also, the sealing hole may be omitted. The same applies to the connection point between the motor case and the front frame.

[0085] In the above embodiment, the heat dissipation ribs, cover member, or flow path portion are provided in the axial projection area of ​​the heat-generating component. In other embodiments, depending on the thermal mass of the controller housing, the heat dissipation ribs, cover member, flow path portion, or other configurations for improving heat dissipation may be omitted, or a combination of these may be provided.

[0086] In the above embodiment, the connector is provided on the motor side of the circuit board, with its opening facing the output end in the axial direction. In other embodiments, the connector may be provided on the cover side of the circuit board, or the opening may face in a different direction. Furthermore, multiple connectors may be provided. The arrangement of elements on the circuit board may also be different from that in the above embodiment.

[0087] In the above embodiment, the controller is formed to extend radially outward beyond the motor area. In other embodiments, the controller may be provided within the motor area. In the above embodiment, the drive device is applied to an electric power steering device. In other embodiments, the drive device may be applied to an in-vehicle device other than an electric power steering device, or may be applied to a device other than an in-vehicle device.

[0088] It may also be stated as "a drive device described in any one of aspects 1 to 5, in which the electronic components include a heat-generating component (54) that generates heat when current is applied, and the controller housing has at least one of a heat dissipation fin (621, 711, 721, 722) and a flow path portion (751) through which a fluid can flow formed at a location where the heat-generating component is projected in the axial direction."

[0089] It may also be stated as "a drive device according to any one of aspects 1 to 6, wherein the controller housing (607) is provided with cover members (741, 742) at locations where the electronic components are projected in the axial direction."

[0090] It may also be stated as "a drive device described in any one of aspects 1 to 7, wherein the controller housing (609) has a communication hole (761) that connects the connection point between the board and the motor wire to the outside, and the opening of the communication hole is blocked by a sealing cover (765)."

[0091] It may also be stated as "A drive device according to any one of aspects 1 to 7, in which the motor wire is electrically connected to the board by a solderless connection, and the controller housing (610) has a terminal escape groove (771) formed at a location corresponding to the connection between the motor wire and the board."

[0092] As described above, the present disclosure is not limited to the above-described embodiment, and can be implemented in various forms without departing from the spirit of the present disclosure.

[0093] The present disclosure has been described based on the embodiments. However, the present disclosure is not limited to the embodiments and structures. The present disclosure also encompasses various modifications and variations within the scope of equivalents. Furthermore, various combinations and forms, as well as other combinations and forms including only one element, more than one element, or less than one element, are also within the scope and spirit of the present disclosure.

Claims

1. A drive device comprising: a motor housing (15, 150) having a cylindrical motor case (16), a stator (12) fixed to the motor housing, motor wires (11) wound around the stator, a rotor (13) that rotates when current is applied to the motor wire, and a motor (10) having a shaft (14) that rotates integrally with the rotor; and a controller (50) fixed to one axial side of the motor case, the controller housing having a board (53) on which electronic components (54, 55) related to drive control of the motor are mounted, and a controller housing (601-610) that accommodates the board, wherein at least a portion of the electronic components are sealed while embedded in the controller housing formed of an insulating material.

2. A drive device as described in claim 1, wherein the controller housing has a first housing (61-64, 66-68) fixed to the motor case, and a second housing (71-77) that seals the electronic components mounted on the side of the board opposite the motor.

3. A drive unit as described in claim 2, wherein the first housing has a through hole (612) in which the controller side end of the shaft is positioned, and the second housing (72) seals the electronic components mounted outside the through hole on the motor side surface of the board.

4. A drive device according to claim 2 or 3, wherein the first housing (61 to 63) seals the end of the motor case on the controller side.

5. The drive device described in claim 1, wherein the motor housing (150) has a frame member (19) that is fixed to the motor case on the controller side of the stator and has a board holding portion (191) that protrudes toward the controller and holds the board, and the controller housing (604) integrally seals the controller side end of the motor case and both sides of the board.

6. A drive unit as described in claim 1, wherein the electronic components include a heat-generating component (54) that generates heat when current is passed through it, and the controller housing is formed with at least one of heat dissipation fins (621, 711, 721, 722) and a flow path portion (751) through which a fluid can flow at a location where the heat-generating component is projected in the axial direction.

7. The drive unit according to claim 1, wherein cover members (741, 742) are provided on the controller housing (607) at locations where the electronic components are projected in the axial direction.

8. The drive device as described in claim 1, wherein the controller housing (609) has a communication hole (761) that connects the connection point between the board and the motor wire to the outside, and the opening of the communication hole is blocked by a sealing cover (765).

9. A drive device as described in claim 1, wherein the motor wire is electrically connected to the board by a solderless connection, and the controller housing (610) has a terminal escape groove (771) formed at a location corresponding to the connection between the motor wire and the board.

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