JP6864029B2 - Electric drive - Google Patents

Description

The present invention relates to an electric drive device and an electric power steering device, and more particularly to an electric drive device and an electric power steering device having a built-in electronic control device.

In the general industrial machinery field, mechanical control elements are driven by electric motors, but recently, electronic control units consisting of semiconductor elements that control the rotational speed and rotational torque of electric motors are electrically operated. So-called mechanical and electrical integrated electric drive devices that are integrated into the motor are beginning to be adopted.

As an example of an electric drive device integrated with electromechanics, for example, in an electric power steering device of an automobile, the rotation direction and rotation torque of the steering shaft that is rotated by the driver operating the steering wheel are detected, and the rotation torque is detected. The electric motor is driven so as to rotate in the same direction as the rotation direction of the steering shaft based on the detected value, and the steering assist torque is generated. In order to control this electric motor, an electronic control unit (ECU: Electronic Control Unit) is provided in the power steering device.

As a conventional electric power steering device, for example, the one described in Japanese Patent Application Laid-Open No. 2015-134598 (Patent Document 1) is known. Patent Document 1 describes an electric power steering device including an electric motor unit and an electronic control unit. The electric motor of the electric motor unit is housed in a motor housing having a tubular portion made of aluminum alloy or the like, and the substrate on which the electronic components of the electronic control unit are mounted is different from the output shaft in the axial direction of the motor housing. It is housed in an ECU housing arranged on the opposite side. The substrate housed inside the ECU housing includes a power supply circuit unit, a power conversion circuit unit having a power switching element such as a MOSFET or IGBT for driving and controlling an electric motor, and a control circuit unit for controlling the power switching element. The output terminal of the power switching element and the input terminal of the electric motor are electrically connected via a bus bar.

Then, electric power is supplied from the power supply to the electronic control unit housed in the ECU housing via the connector terminal assembly made of synthetic resin, and detection signals such as the operating state are supplied from the detection sensors. .. The connector terminal assembly functions as a lid, is connected to the electronic control unit so as to close the opening formed in the ECU housing, and is fixed to the outer surface of the ECU housing by a fixing bolt.

In addition to this, as an electric drive device integrated with an electronic control device, an electric brake, an electric hydraulic controller for various flood control, etc. are known, but in the following description, the electric power steering device is represented as a representative. explain.

Japanese Unexamined Patent Publication No. 2015-134598

By the way, since the electric power steering device described in Patent Document 1 is arranged in the engine room of an automobile, it is necessary to be compact. Especially in recent years, many auxiliary equipment such as exhaust gas countermeasure equipment and safety countermeasure equipment have tended to be installed in the engine room of automobiles, and various auxiliary equipment including electric power steering equipment should be made as small as possible. It is required to reduce the number of parts.

In the electric power steering device having the configuration as described in Patent Document 1, a heat sink member for radiating heat from the power supply circuit section and the power conversion circuit section to the outside is arranged between the motor housing and the ECU housing. ing. Therefore, the length in the axial direction tends to be excessively increased by the amount of the heat sink member. Further, the electric components constituting the power supply circuit section and the power conversion circuit section generate a large amount of heat, and when the size is reduced, it is necessary to efficiently dissipate the heat to the outside. Therefore, there is a demand for an electric drive device that can make the length in the axial direction as short as possible and efficiently dissipate the heat of the power supply circuit unit and the power conversion circuit unit to the outside.

An object of the present invention is to provide a novel electric drive device and electric power steering device capable of making the length in the axial direction as short as possible and efficiently dissipating the heat of the power supply circuit unit and the power conversion circuit unit to the outside. There is.

A feature of the present invention is that a heat radiating portion that transfers heat generated at least in the power supply circuit portion and the power conversion circuit portion to the motor housing is formed on the end surface portion of the motor housing on the side opposite to the output portion of the rotating shaft of the electric motor. It's there.

According to the present invention, by transferring the heat generated in the power supply circuit section and the power conversion circuit section to the end face portion of the motor housing, the heat sink member can be omitted and the axial length can be shortened. Further, since the motor housing has a sufficient heat capacity, the heat of the power supply circuit section and the power conversion circuit section can be efficiently dissipated to the outside.

It is an overall perspective view of the steering apparatus as an example to which this invention is applied. It is an overall perspective view of the electric power steering apparatus which becomes an embodiment of this invention. It is an exploded perspective view of the electric power steering apparatus shown in FIG. It is a perspective view of the motor housing shown in FIG. FIG. 5 is a cross-sectional view of the motor housing shown in FIG. 4 in the axial direction. It is a perspective view which shows the state which the power conversion circuit part is mounted on the motor housing shown in FIG. It is a perspective view which shows the state which the power supply circuit part is mounted on the motor housing shown in FIG. It is a perspective view which shows the state which the control circuit part is mounted on the motor housing shown in FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings, but the present invention is not limited to the following embodiments, and various modifications and applications are included in the technical concept of the present invention. Is also included in that range.

Before explaining the embodiment of the present invention, the configuration of the steering device as an example to which the present invention is applied will be briefly described with reference to FIG.

First, a steering device for steering the front wheels of an automobile will be described. The steering device 1 is configured as shown in FIG. A pinion (not shown) is provided at the lower end of the steering shaft 2 connected to a steering wheel (not shown), and this pinion meshes with a rack (not shown) that is long in the left-right direction of the vehicle body. Tie rods 3 for steering the front wheels in the left-right direction are connected to both ends of the rack, and the rack is covered with a rack housing 4. A rubber boot 5 is provided between the rack housing 4 and the tie rod 3.

An electric power steering device 6 is provided to assist the torque when rotating the steering wheel. That is, the electric motor unit 8 is provided with a torque sensor 7 that detects the rotation direction and the rotation torque of the steering shaft 2, and applies a steering assist force to the rack via the gear 10 based on the detection value of the torque sensor 7. And an electronic control device (ECU) unit 9 for controlling the electric motor arranged in the electric motor unit 8. The electric motor unit 8 of the electric power steering device 6 is connected to the gear 10 via bolts (not shown) at three locations on the outer peripheral portion on the output shaft side, and the electronic control unit 9 is on the side opposite to the output shaft of the electric motor 8 unit. Is provided.

In the electric power steering device 6, when the steering shaft 2 is rotated in any direction by operating the steering wheel, the torque sensor 7 determines the rotation direction and rotation torque of the steering shaft 2. It is detected, and the control circuit unit calculates the drive operation amount of the electric motor based on the detected value. The electric motor is driven by the power switching element of the power conversion circuit unit based on the calculated drive operation amount, and the output shaft of the electric motor is rotated so as to drive the steering shaft 1 in the same direction as the operation direction. The rotation of the output shaft is transmitted from a pinion (not shown) to a rack (not shown) via a gear 10, and the automobile is steered. Since these configurations and actions are already well known, further description thereof will be omitted.

As described above, in the electric power steering device having the configuration as described in Patent Document 1, the heat sink member for radiating the heat of the power supply circuit section and the power conversion circuit section to the outside is particularly between the motor housing and the ECU housing. Is located in. Therefore, the length in the axial direction tends to be excessively increased by the amount of the heat sink member. Further, the electric components constituting the power supply circuit section and the power conversion circuit section generate a large amount of heat, and when the size is reduced, it is necessary to efficiently dissipate the heat to the outside. Therefore, there is a demand for an electric drive device that can make the length in the axial direction as short as possible and efficiently dissipate the heat of the power supply circuit unit and the power conversion circuit unit to the outside.

Against this background, the present embodiment proposes an electric power steering device having the following configuration. That is, in the present embodiment, a heat radiating unit that transfers heat generated at least in the power supply circuit unit and the power conversion circuit unit to the motor housing on the end surface portion of the motor housing on the side opposite to the output portion of the rotating shaft of the electric motor. It is a structure that forms. According to such a configuration, by transferring the heat generated in the power supply circuit section and the power conversion circuit section to the end face portion of the motor housing, the heat sink member can be omitted and the axial length can be shortened. .. Further, since the motor housing has a sufficient heat capacity, the heat of the power supply circuit section and the power conversion circuit section can be efficiently dissipated to the outside.

Hereinafter, a specific configuration of the electric power steering device according to the embodiment of the present invention will be described in detail with reference to FIGS. 2 to 8. Note that FIG. 2 is a drawing showing the overall configuration of the electric power steering device according to the present embodiment, and FIG. 3 is a drawing in which the components of the electric power steering device shown in FIG. 2 are disassembled and viewed from an oblique direction. 4 to 8 are drawings showing a state in which each component is assembled according to the assembly order of each component. Therefore, in the following description, the description will be given with reference to each drawing as appropriate.

As shown in FIG. 2, the electric motor portion 8 constituting the electric power steering device is composed of a motor housing 11 having a tubular portion made of an aluminum alloy or the like and an electric motor (not shown) housed therein. The control unit 9 is composed of a metal cover 12 made of an aluminum alloy or the like, which is arranged on the side opposite to the output shaft in the axial direction of the motor housing 11, and an electronically controlled assembly (not shown) housed therein. ..

The motor housing 11 and the metal cover 12 are integrally fixed at their opposite end faces by an adhesive, welding, or fixing bolts. The electronically controlled assembly housed inside the metal cover 12 has a power supply circuit unit that generates a necessary power supply, and a power conversion element having a power switching element including a MOSFET or an IGBT that drives and controls the electric motor of the electric motor unit 8. It consists of a circuit and a control circuit unit that controls the power switching element, and the output terminal of the power switching element and the coil input terminal of the electric motor are electrically connected via a bus bar.

The connector terminal assembly 13 is fixed to the end surface of the metal cover 12 by fixing bolts. The connector terminal assembly 13 includes a connector terminal forming unit 13A for supplying power, a connector terminal forming unit 13B for a detection sensor, and a connector terminal forming unit 13C for transmitting a control state to an external device. Then, the electronically controlled assembly housed in the metal cover 12 is supplied with power from the power supply via the connector terminal forming portion 13A for power supply made of synthetic resin, and the detection sensors detect the operating state and the like. The signal is supplied via the connector terminal forming unit 13B for the detection sensor, and the control state signal of the current electric power steering device is transmitted via the connector terminal forming terminal 13C for transmitting the control state.

FIG. 3 shows an exploded perspective view of the electric power steering device 6. An annular iron side yoke (not shown) is fitted inside the motor housing 11, and an electric motor (not shown) is housed in the side yoke. The output unit 14 of the electric motor applies a steering assisting force to the rack via gears. Since the specific structure of the electric motor is well known, the description thereof will be omitted here.

The motor housing 11 is made of an aluminum alloy, and functions as a heat sink member that releases heat generated by an electric motor and heat generated by a power supply circuit unit and a power conversion circuit unit, which will be described later, to the outside atmosphere. The electric motor and the motor housing 11 form an electric motor section.

An electronic control unit EC is attached to an end surface portion 15 of the motor housing 11 on the opposite side of the output portion 14 of the electric motor unit. The electronic control unit EC includes a power conversion circuit unit 16, a power supply circuit unit 17, and a control circuit unit 18. The end face portion 15 of the motor housing 11 is integrally formed with the motor housing 11, but in addition to this, only the end face portion 15 may be formed separately and integrated with the motor housing 11 by bolts or welding. Is.

Here, the power conversion circuit unit 16, the power supply circuit unit 17, and the control circuit unit 18 form a redundant system, and form a dual system of a main electronic control unit and a sub electronic control unit. Normally, the electric motor is controlled and driven by the main electronic control unit, but when an abnormality or failure occurs in the main electronic control unit, it is switched to the sub-electronic control unit so that the electric motor is controlled and driven. It will be.

Therefore, as will be described later, normally, heat from the main electronic control unit is transferred to the motor housing 11, and when an abnormality or failure occurs in the main electronic control unit, the main electronic control unit stops and the sub electronic control unit operates. The heat from the sub-electronic control unit is transferred to the motor housing 11.

However, although it is not adopted in this embodiment, the main electronic control unit and the sub electronic control unit are combined to function as a regular electronic control unit, and when an abnormality or failure occurs in one electronic control unit, the other electronic control unit is controlled. It is also possible to control and drive the electric motor with half the capacity of the unit. In this case, the capacity of the electric motor is halved, but the so-called "limp home function" is secured. Therefore, in a normal case, the heat of the main electronic control unit and the sub electronic control unit is transferred to the motor housing 11.

The electronic control unit EC is composed of a control circuit unit 18, a power supply circuit unit 17, a power conversion circuit unit 16, and a connector terminal assembly 13, and the power conversion circuit unit 16 and a power supply are provided in a direction away from the end face portion 15 side. The circuit unit 17, the control circuit unit 18, and the connector terminal assembly 13 are arranged in this order. The control circuit unit 18 generates a control signal for driving the switching element of the power conversion circuit unit 16, and is composed of a microcomputer, peripheral circuits, and the like. The power supply circuit unit 17 generates a power supply for driving the control circuit unit 18 and a power supply for the power conversion circuit unit 16, and is composed of a capacitor, a coil, a switching element, and the like. The power conversion circuit unit 16 adjusts the power flowing through the coil of the electric motor, and is composed of switching elements and the like that form a three-phase upper and lower arm.

The electric power conversion circuit unit 16 and the power supply circuit unit 17 mainly generate a large amount of heat in the electronic control unit EC, and the heat of the power conversion circuit unit 16 and the power supply circuit unit 17 is dissipated from the motor housing 11 made of an aluminum alloy. Is to be done. This configuration will be described later.

A connector terminal assembly 13 made of synthetic resin is provided between the control circuit unit 18 and the metal cover 12, and the current control state of the vehicle battery (power supply) and the electric power steering device is not shown externally. It is connected to the control device. Of course, it goes without saying that the connector terminal assembly 13 is connected to the power conversion circuit unit 16, the power supply circuit unit 17, and the control circuit unit 18.

The metal cover 12 has a function of accommodating the power conversion circuit unit 16, the power supply circuit unit 17, and the control circuit unit 18 and sealing them liquid-tightly. In the present embodiment, the motor housing is welded. It is fixed at 11. Since the metal cover 12 is made of metal, it also has a function of dissipating heat generated by the power conversion circuit unit 16, the power supply circuit unit 17, and the like to the outside.

Next, the configuration and assembly method of each component will be described with reference to FIGS. 4 to 8. First, FIG. 4 shows the appearance of the motor housing 11, and FIG. 5 shows the axial cross section thereof. In FIGS. 4 and 5, the motor housing 11 is formed in a tubular shape and closes the side peripheral surface portion 11A, the end surface portion 15 that closes one end of the side peripheral surface portion 11A, and the other end of the side peripheral surface portion 11A. It is composed of an end face portion 19. In the present embodiment, the motor housing 11 has a bottomed cylindrical shape, and the side peripheral surface portion 11A and the end surface portion 15 are integrally formed. Further, the end face portion 19 has a function of a lid, and closes the other end of the side peripheral surface portion 11A after the electric motor is housed in the side peripheral surface portion 11A.

As shown in FIG. 5, a stator 21 in which a coil 20 is wound around an iron core is fitted inside the side peripheral surface portion 11A, and a rotor 22 in which a permanent magnet is embedded rotates inside the stator 21. It is stored as possible. A rotation shaft 23 is fixed to the rotor 22, one end of which is an output unit 14, and the other end of which is a rotation detection unit 24 for detecting the rotation phase and rotation speed of the rotation shaft 23. A permanent magnet is provided in the rotation detection unit 24, and penetrates through a through hole 25 provided in the end face portion 15 and projects to the outside. Then, the rotation phase and the rotation speed of the rotation shaft 23 are detected by a magnetic sensitive portion composed of a GMR element or the like (not shown).

Returning to FIG. 4, the power conversion circuit unit 16 (see FIG. 3) and the power supply circuit unit 17 (see FIG. The heat radiating portions (15A, 15B) of (see FIG. 3) are formed. Substrate-fixing convex portions 26 are integrally planted at the four corners of the end face portion 15, and screw holes are formed inside. The board fixing convex portion 26 is provided to fix the board of the control circuit section 18 described later. Further, the substrate fixing convex portion 26 planted from the power conversion heat dissipation region 15A described later is also formed with a substrate receiving portion 27 having the same height in the axial direction as the power supply heat dissipation region 15B described later. The substrate receiving portion 27 is for mounting the glass epoxy substrate 31 of the power supply circuit portion 17, which will be described later.
The radial plane region orthogonal to the rotation axis 23 forming the end face portion 15 is divided into two. One forms a power conversion heat dissipation region 15A to which the power conversion circuit unit 16 is attached, and the other forms a power supply heat dissipation region 15B to which the power supply circuit unit 17 is attached. In the present embodiment, the heat dissipation region 15A for power conversion has a larger area than the heat dissipation region 15B for power supply. This is because the dual system is adopted as described above, so that the installation area of the power conversion circuit unit 16 is secured.

The power conversion heat dissipation region 15A and the power supply heat dissipation region 15B have steps having different heights in the axial direction (direction in which the rotating shaft 23 extends). That is, the heat dissipation region 15B for power supply is formed so as to have a step in the direction away from the heat dissipation region 15A for power conversion when viewed in the direction of the rotation shaft 23 of the electric motor. This step is set to a length so that the power conversion circuit unit 16 and the power supply circuit unit 17 do not interfere with each other when the power supply circuit unit 17 is installed after the power conversion circuit unit 16 is installed.

Three elongated rectangular protruding heat radiating portions 28 are formed in the power conversion heat radiating region 15A. The protruding heat radiating unit 28 is provided with a dual power conversion circuit unit 16 described later. Further, the protruding heat radiating portion 28 projects and extends in a direction away from the electric motor when viewed in the direction of the rotating shaft 23 of the electric motor.

Further, the heat dissipation region 15B for power supply is flat, and a power supply circuit unit 17, which will be described later, is installed. Therefore, the protruding heat radiating unit 28 functions as a heat radiating unit that transfers the heat generated by the power conversion circuit unit 16 to the end face portion 15, and the heat radiating region 15B for power supply transfers the heat generated by the power supply circuit unit 17 to the end face portion 15. It functions as a heat radiating unit that transfers heat.

The protruding heat radiating unit 28 can be omitted. In this case, the power conversion heat radiating region 15A functions as a heat radiating unit that transfers the heat generated by the power conversion circuit unit 16 to the end face portion 15. However, in the present embodiment, the metal substrate of the power conversion circuit unit 16 is welded to the protruding heat radiating unit 28 by friction stir welding to ensure reliable fixing.

As described above, in the end face portion 15 of the motor housing 11 according to the present embodiment, the heat sink member can be omitted and the length in the axial direction can be shortened. Further, since the motor housing 11 has a sufficient heat capacity, the heat of the power supply circuit unit 17 and the power conversion circuit unit 16 can be efficiently dissipated to the outside.

Next, FIG. 6 shows a state in which the power conversion circuit unit 16 is installed in the ridge heat dissipation unit 28 (see FIG. 4). As shown in FIG. 6, a power conversion circuit unit 16 composed of a dual system is installed above the protruding heat radiation unit 28 (see FIG. 4) formed in the power conversion heat dissipation region 15A. The switching element constituting the power conversion circuit unit 16 is mounted on a metal substrate (here, an aluminum-based metal is used), and is configured to easily dissipate heat. The metal substrate is welded to the protruding heat radiating portion 28 by friction stir welding.

Therefore, the metal substrate is firmly fixed to the protruding heat radiating portion 28 (see FIG. 4), and the heat generated by the switching element can be efficiently transferred to the protruding heat radiating portion 28 (see FIG. 4). The heat transferred to the protruding heat radiating portion 28 (see FIG. 4) is diffused to the power conversion heat radiating region 15A, further transferred to the side peripheral surface portion 11A of the motor housing 11, and radiated to the outside. Here, as described above, the height of the power conversion circuit unit 16 in the axial direction is lower than the height of the power supply heat dissipation region 15B, so that the power conversion circuit unit 16 does not interfere with the power supply circuit unit 17, which will be described later.

Next, FIG. 7 shows a state in which the power supply circuit unit 17 is installed from above the power conversion circuit unit 16. As shown in FIG. 7, a power supply circuit unit 17 is installed above the heat dissipation region 15B for power supply. The capacitors 29, coils 30, and the like that make up the power supply circuit unit 17 are mounted on the glass epoxy board 31. A dual system is also adopted for the power supply circuit unit 17, and as can be seen from the figure, a power supply circuit composed of a capacitor 29, a coil 30, and the like is formed symmetrically.

The surface of the glass epoxy substrate 31 on the power supply heat dissipation region 15B (see FIG. 6) side is fixed to the end face portion 15 so as to be in contact with the power supply heat dissipation region 15B. As shown in FIG. 7, the fixing method is fixed to a screw hole provided in the board receiving portion 27 of the board fixing convex portion 26 by a fixing bolt (not shown). Further, it is also fixed to a screw hole provided in the heat dissipation region 15B for power supply (see FIG. 6) by a fixing bolt (not shown).

Since the power supply circuit portion 17 is formed of the glass epoxy substrate 31, double-sided mounting is possible. A rotation phase and rotation speed detection unit including a GMR element (not shown) and a detection circuit thereof is mounted on the surface of the glass epoxy substrate 31 on the power dissipation region 15B (see FIG. 6) side, and the rotation shaft 23 (see FIG. 6). In cooperation with the rotation detection unit 24 (see FIG. 5) provided in (see FIG. 5), the rotation phase and rotation speed of rotation are detected.

In this way, since the glass epoxy substrate 31 is fixed so as to be in contact with the heat dissipation region 15B for power supply (see FIG. 6), the heat generated in the power supply circuit unit 17 is efficiently dissipated to the heat dissipation region 15B for power supply (FIG. 6). Heat can be transferred to (see). The heat transferred to the heat dissipation region 15B for power supply (see FIG. 6) is diffused to the side peripheral surface portion 11A of the motor housing 11 and transferred to the outside to be dissipated to the outside. Here, by interposing any one of an adhesive having good heat transfer, a heat radiating grease, and a heat radiating sheet between the glass epoxy substrate 31 and the heat radiating region 15B for power supply (see FIG. 6), the heat transfer performance is further improved. Can be improved.

Next, FIG. 8 shows a state in which the control circuit 18 is installed from above the power supply circuit unit 17. As shown in FIG. 8, a control circuit unit 18 is installed above the power supply circuit unit 17. The microprocessor 32 and the peripheral circuit 33 constituting the control circuit unit 18 are mounted on the glass epoxy board 34. A dual system is also adopted for the control circuit unit 18, and as can be seen from the figure, a control circuit composed of a microcomputer 32 and a peripheral circuit 33 is formed for each target. The microcomputer 32 and the peripheral circuit 33 may be provided on the surface of the glass epoxy substrate 34 on the power supply circuit 17 side.

As shown in FIG. 8, the glass epoxy substrate 34 is fixed to a screw hole provided at the top of the substrate fixing convex portion 26 (see FIG. 7) by a fixing bolt (not shown), and is fixed to the power supply circuit portion 17 (FIG. 7). The space between the glass epoxy board 31 of (see) and the glass epoxy board 34 of the control circuit unit 18 is a space in which the capacitor 29, the coil 30, and the like of the power supply circuit unit 17 shown in FIG. 7 are arranged.

Next, in the state shown in FIG. 3, the connector terminal assembly 13 is connected to the power conversion circuit unit 16, the power supply circuit unit 17, and the control circuit unit 18, and further, as shown in FIG. 2, the power conversion circuit unit is connected by the metal cover 12. 16, the power supply circuit unit 17, and the control circuit unit 18 are liquid-tightly sealed. This completes the assembly of the electric power steering device.

As described above, according to the present embodiment, the power conversion circuit unit 16 is installed above the protruding heat radiating unit 28 formed in the power conversion heat radiating region 15A. Therefore, the heat generated by the switching element of the power conversion circuit unit 16 can be efficiently transferred to the protruding heat radiating unit 28. Further, the heat transferred to the protruding heat radiating portion 28 is diffused to the power conversion heat radiating region 15A, and is transferred to the side peripheral surface portion 11A of the motor housing 11 to be dissipated to the outside.

Similarly, a power supply circuit unit 17 is installed above the heat dissipation region 15B for power supply. The surface of the glass epoxy board 31 on which the circuit element of the power supply circuit portion 17 is placed on the power dissipation region 15B side is fixed to the end surface portion 15 so as to be in contact with the power supply heat dissipation region 15B. Therefore, the heat generated in the power supply circuit unit 17 can be efficiently transferred to the heat dissipation region 15B for the power supply. The heat transferred to the heat dissipation region 15B for the power supply is diffused to the side peripheral surface portion 11A of the motor housing 11 and transferred to the outside to be dissipated to the outside.

According to such a configuration, at least the heat generated in the power supply circuit unit 17 and the power conversion circuit unit 16 is transferred to the end face portion 15 of the motor housing 11, so that the heat sink member is omitted and the length in the axial direction is reduced. You will be able to shorten it. Further, since the motor housing 11 has a sufficient heat capacity, the heat of the power supply circuit unit and the power conversion circuit unit can be efficiently dissipated to the outside.

As described above, the present invention is a heat radiating unit that transfers heat generated at least in the power supply circuit unit and the power conversion circuit unit to the motor housing on the end surface portion of the motor housing on the side opposite to the output portion of the rotating shaft of the electric motor. The composition that formed the above is adopted. According to this, by transferring the heat generated in the power supply circuit section and the power conversion circuit section to the end face portion of the motor housing, the heat sink member can be omitted and the length in the axial direction can be shortened. Further, since the motor housing has a sufficient heat capacity, the heat of the power supply circuit section and the power conversion circuit section can be efficiently dissipated to the outside.

The present invention is not limited to the above-described embodiment, and includes various modifications. For example, the above-described embodiment has been described in detail in order to explain the present invention in an easy-to-understand manner, and is not necessarily limited to the one including all the described configurations. Further, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. Further, it is possible to add / delete / replace a part of the configuration of each embodiment with another configuration.

6 ... Electric power steering device, 8 ... Electric motor unit, 9 ... Electronic control unit, 11 ... Motor housing, 12 ... Metal cover, 13 ... Connector terminal assembly, 14 ... Output unit, 15 ... End face part, 16 ... Power conversion Circuit unit, 17 ... Power supply circuit unit, 18 ... Control circuit unit, 19 ... End face part, 20 ... Coil, 21 ... Stator, 22 ... Rotor, 23 ... Rotating shaft, 24 ... Rotation detection unit, 25 ... Through hole, 26 ... Substrate fixing convex portion, 27 ... Substrate receiving portion, 28 ... Protruding heat dissipation part, 29 ... Capacitor, 30 ... Coil, 31 ... Glass epoxy substrate, 32 ... Microcomputer, 33 ... Peripheral circuit, 34 ... Glass epoxy substrate.

Claims (10)

A motor housing that has a rotor with a fixed stator and rotating shaft and houses an electric motor that drives mechanical control elements.
Permanent magnets provided at the shaft ends on the side opposite to the output side of the rotating shaft of the electric motor,
As an electronic control unit that is arranged on the side opposite to the output side of the rotation shaft of the electric motor and controls the electric motor, a control circuit unit and a power supply circuit unit in which a microcomputer is installed are provided, and the power supply circuit unit is provided. Is equipped with a magnetic sensitive portion that detects the rotation of the rotating shaft in cooperation with the permanent magnet.
The end face portion of the motor housing is formed with a step so that the height differs in the direction of the rotation axis of the electric motor.
The power supply circuit unit is located on the side of the electric motor and on the side where the height of the step is higher than that of the control circuit unit.
The tip of the permanent magnet protrudes through a through hole provided in the end face portion on the lower side of the step and is located on the side of the power supply circuit portion.
An electric drive device characterized by this. The electric motor that drives the mechanical control elements is housed in the motor housing.
It has an electronic control unit that is arranged on the side opposite to the output side of the rotation shaft of the electric motor and controls the electric motor.
The electronic control unit includes a control circuit unit and a power supply circuit unit in which a microcomputer is installed, and a power conversion circuit unit that controls a current flowing through the electric motor .
The end face portion of the motor housing is formed with a step so that the height differs in the direction of the rotation axis of the electric motor.
The power conversion circuit unit and the power supply circuit unit are located between the control circuit unit and the electric motor, and are arranged in contact with each other at different steps of the end face portion of the motor housing.
An electric drive device characterized by this. The electric motor that drives the mechanical control elements is housed in the motor housing.
It has an electronic control unit that is arranged on the side opposite to the output side of the rotation shaft of the electric motor and controls the electric motor.
The electronic control unit includes a power supply circuit unit, a control circuit unit in which a microcomputer is installed, and a power conversion circuit unit that controls a current flowing through the electric motor.
Wherein the control circuit section, in the direction of the rotation shaft of the electric motor, is arranged from the electric motor than the power supply circuit unit and the power converting circuit unit at a position apart in the direction of the rotation shaft of the electric motor,
The end face portion of the motor housing has a step so that the height differs in the direction of the rotation axis of the electric motor.
The power conversion circuit unit is arranged on the side where the height of the step is low in the direction of the rotation axis, and the power supply circuit unit is arranged on the side where the height of the step is high in the direction of the rotation axis.
An electric drive device characterized by this. In the electric drive device according to claim 1 or 3.
An electric drive device characterized in that any one of a heat-transferring adhesive, heat-dissipating grease, and heat-dissipating sheet is interposed between the power supply circuit portion and the end face portion. In the electric drive device according to claim 2 or 3.
The electric power conversion circuit unit is an electric drive device characterized in that the electric power conversion circuit unit is divided and arranged so as to face each other on both sides of the rotation axis of the electric motor. In the electric drive device according to claim 3,
The power conversion circuit unit is a dual system and is divided into three power conversion circuits, so that two of the three power conversion circuits face each other with the rotation axis of the electric motor as a boundary. Placed in
The other one is an electric drive device characterized in that it is arranged at a position sandwiched between two power conversion circuits outside the rotation shaft of the electric motor. In the electric drive device according to claim 2 or 3.
The said end face has a projecting portion formed to protrude in the direction of the rotation shaft of the electric motor, the power converter circuit portion is characterized in that it is placed in contact with the protrusion Electric drive device. In the electric drive device according to claim 1,
In the end face portion, the area on the side where the step is low is formed larger than the area on the side where the step is low.
An electric drive device characterized by this. In the electric drive device according to claim 3,
The rotating shaft of the electric motor extends through the end face portion until it approaches the substrate of the power supply circuit portion.
A detection unit for detecting the rotational state of the rotating shaft is mounted on the substrate of the power supply circuit unit.
An electric drive device characterized by this. The electric drive device according to any one of claims 1 to 3.
The motor housing is formed in a bottomed cylindrical shape having a side peripheral surface portion in which the electric motor is housed and the end face portion, and the side peripheral surface portion on the side opposite to the end face portion is different from the side peripheral surface portion. It is blocked by a separate second end face
An electric drive device characterized by this.

Images