Motor control device, motor, and electric power steering device

A motor control device includes a frame including a metal material, a substrate disposed on an upper side of the frame with a gap between the substrate and the upper side of the frame member, the substrate including a hole penetrating an upper surface and a lower surface, a wiring that is inserted into the hole from a side of the upper surface of the substrate, and a tip portion connected to the substrate, and an insulating spacer interposed between the frame and the substrate. The spacer includes a side wall portion that surrounds the tip portion of the wiring in a plan view.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present disclosure relates to a motor control device, a motor, and an electric power steering device.

2. Description of the Related Art

In a motor equipped with a control device, a structure is known in which a tip portion (connector terminal) of a wiring for supplying electric power and a signal is connected by press fitting.

There is a problem that the dimension of the motor increases.

SUMMARY OF THE INVENTION

A motor control device of a motor according to an example embodiment of the present invention includes a frame including a metal material, a substrate disposed on an upper side of the frame with a gap between the substrate and the upper side of the frame, the substrate including a hole penetrating an upper surface and a lower surface, a wiring that is inserted into the hole from a side of the upper surface of the substrate, and a tip portion connected to the substrate, and an insulating spacer interposed between the frame and the substrate. The spacer includes a side wall portion that surrounds the tip portion of the wiring in a plan view.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, a motor according to an embodiment of the present invention will be described with reference to the drawings. Note that the scope of the present invention is not limited to the embodiment described below, but may be arbitrarily changed within the technical spirit of the present invention. Also note that scales, numbers, and the like of the structures illustrated in the following drawings may differ from those of actual structures, for the sake of easier understanding of the configurations.

In the accompanying drawings, an xyz coordinate system is shown appropriately as a three-dimensional orthogonal coordinate system. In the xyz coordinate system, a z-axis direction is assumed to be a direction parallel to the axial direction of a center axis J shown inFIG. 1. An x-axis direction is assumed to be a direction orthogonal to the z-axis direction, and is assumed to be a lateral direction inFIG. 1. A y-axis direction is assumed to be a direction orthogonal to both the x-axis direction and the z-axis direction.

In the following description, the positive side (+z side, one side) in the z-axis direction is referred to as an “upper side”, and the negative side (−z side, the other side) in the z-axis direction is referred to as a “lower side”. It should be noted, however, that the above definitions of the upper side and the lower side are made simply for the sake of description, and are not meant to restrict actual relative positions or directions. Also, unless otherwise explained, a direction (z-axis direction) parallel to the center axis J is simply referred to as an “axial direction”, a radial direction having its center on the center axis J is simply referred to as a “radial direction”, and a circumferential direction having its center on the center axis J, that is, a direction around the center axis J, is simply referred to as a “circumferential direction”. In addition, in the present description, the plan view refers to the case of seeing along the z-axis direction.

FIG. 1is a cross-sectional view showing a motor1according to the present embodiment.FIG. 2is an enlarged cross-sectional view in which a part (the vicinity of a spacer80) ofFIG. 1is enlarged. Further,FIG. 3is a cross-sectional view taken along line ofFIG. 2.

The motor1includes a main body unit3, and a motor control device (hereinafter simply referred to as a control device)4. The main body unit3mainly constitutes a drive unit of the motor1. The control device4controls the main body unit3. The control device4is positioned on the upper side of the main body unit3. The main body unit3includes a motor housing11, a rotor20having a shaft21, a stator30, an upper-side bearing (bearing)24, a lower-side bearing25, and a sensor magnet63. The control device4includes a substrate housing12, a bearing holder (frame member)40, a lid70, the spacer80, a first substrate66, a second substrate67, a plurality of connection pins (wirings)51, and heat dissipation grease (heat dissipation material) G.

The motor housing11and the substrate housing12accommodate respective units (mainly, the main body unit3) of the motor1therein. The motor housing11has a tubular shape that opens to the upper side (+z side). Further, the substrate housing12has a tubular shape that opens to the lower side (−z side). The motor housing11and the substrate housing12are arranged with their openings facing each other. Between the motor housing11and the substrate housing12, a peripheral edge portion of the bearing holder40, described below, is interposed.

The motor housing11has a first tubular portion14, a first bottom portion13, and a lower-side bearing holding portion18. The first tubular portion14has a tubular shape that surrounds the radially outer side of the stator30. In the present embodiment, the first tubular portion14is in a cylindrical shape, for example. The first tubular portion14is fitted in a stepped portion40bprovided to the peripheral edge of the bearing holder at the upper end. To the inner side surface of the first tubular portion14, the stator30is fixed.

The first bottom portion13is provided at an end portion on the lower side (−z side) of the first tubular portion14. The first bottom portion13is provided with an output shaft hole portion13apenetrating the first bottom portion13in the axial direction (z-axis direction). The lower-side bearing holding portion18is provided to a surface on the upper side (+z side) of the first bottom portion13. The lower-side bearing holding portion18holds the lower-side bearing25.

The substrate housing12is positioned on the upper side (+z side) of the motor housing11. In the present embodiment, the substrate housing12accommodates the first substrate66and the second substrate67. Electronic components and the like are mounted on at least one of the upper surface and the lower surface of the first substrate66and the second substrate67. The substrate housing12has a second tubular portion15and a second bottom portion16.

The second tubular portion15has a tubular shape that surrounds the radially outer sides of the first substrate66and the second substrate67. The second tubular portion15is in a cylindrical shape, for example. At the lower end of the second tubular portion15, a flange portion15ais provided. The second tubular portion15is connected to an upper surface40aof the bearing holder40in the flange portion15a.

The rotor20has a shaft21, a rotor core22, and a rotor magnet23. The shaft21has a columnar shape extending along the center axis J extending in the vertical direction (z-axis direction). The shaft21is supported by the lower-side bearing25and the upper-side bearing24so as to be rotatable about the axis of the center axis J. An end portion on the lower side (−z side) of the shaft21protrudes to the outside of the housing10via the output shaft hole portion13a. To the end portion on the lower side of the shaft21, a coupler (not shown) for connecting to an output target is press-fitted, for example. A hole portion is provided to an upper end surface21aof the shaft21. In the hole portion of the shaft21, an attachment member62is fitted. The attachment member62is a bar-shaped member extending in the axial direction.

The rotor core22is fixed to the shaft21. The rotor core22circumferentially surrounds the shaft21. The rotor magnet23is fixed to the rotor core22. More specifically, the rotor magnet23is fixed to the outer side surface along the circumferential direction of the rotor core22. The rotor core22and the rotor magnet23rotate together with the shaft21. It should be noted that the rotor core22may have a through hole or a concavity, and the rotor magnet23may be accommodated in the through hole or the concavity.

The stator30surrounds the radially outer side of the rotor20. The stator30includes a stator core31, a bobbin32, and a coil33. The bobbin32is made of a material having insulation property. The bobbin32covers at least a part of the stator core31. When the motor1is driven, the coil33excites the stator core31. The coil33is configured by winding a conductive wire. The coil33is provided to the bobbin32. As shown inFIG. 4to be described below, an end portion33aof the conductive wire constituting the coil33extends to the upper side from the coil33, and is connected to the first substrate66through the bearing holder40.

In the present embodiment, the upper-side bearing24is a ball bearing. The upper-side bearing24rotatably supports the upper end portion of the shaft21. The upper-side bearing24is positioned on the upper side (+z side) of the stator30. The upper-side bearing24is held by the bearing holder40. In the present embodiment, the lower-side bearing25is a ball bearing. The lower-side bearing25rotatably supports the lower end portion of the shaft21. The lower-side bearing25is positioned on the lower side (−z side) of the stator30. The lower-side bearing25is held by the lower-side bearing holding portion18of the motor housing11.

The upper-side bearing24and the lower-side bearing25support the shaft21of the rotor20. The types of the upper-side bearing24and the lower-side bearing25are not particularly limited, and other kinds of bearings may be used.

The sensor magnet63is positioned on the upper side (+z side) with respect to the upper-side bearing24. The sensor magnet63is in an annular shape. The sensor magnet63is fitted to the outer side surface of the attachment member62fixed to the shaft21. As a result, the sensor magnet63is attached to the shaft21. Further, the sensor magnet63is positioned above the upper-side bearing24. That is, the sensor magnet63is fixed to the shaft21via the attachment member62on the upper side of the upper-side bearing24at the upper end portion of the shaft21. It should be noted that the shape of the sensor magnet63is not limited to an annular shape, and may be another shape such as a ring shape or a disc shape. In that case, the sensor magnet63may be provided with a concavity, and the tip of the attachment member62may be fixed to the concavity by press fitting, adhesion or the like. Further, the sensor magnet63may be attached directly to the tip of the shaft21.

As shown inFIG. 1, the bearing holder40is positioned on the upper side (+z side) of the stator30. In the present embodiment, the bearing holder40directly holds the upper-side bearing24. The shape of the bearing holder40in a plan view (xy-plane view) is a circular shape concentric with the center axis J, for example. The bearing holder40is made of a metal material. In the present embodiment, the bearing holder40is interposed between the motor housing11and the substrate housing12. Note that the shape of the bearing holder40in the plan view (xy-plane view) is not limited to a circular shape, and may be another shape such as a polygonal shape.

The bearing holder40has the upper surface40afacing upward. The upper surface40afaces the lower surface66aof the first substrate66. On the upper surface40a, a pair of housing concavities (concavities)41are provided. Each of the housing concavities41is recessed downward from the upper surface40a. In addition, the housing concavity41opens upward on the upper surface40a. The pair of housing concavities41are respectively disposed along the peripheral edge portion of the bearing holder40. The pair of housing concavities41are positioned on opposite sides across the center axis J. In the pair of housing concavities41, the spacers80are inserted.

Between the upper surface40aof the bearing holder40and the lower surface66aof the first substrate66, the heat dissipation grease G is positioned. The heat dissipation grease G transmits the heat generated in the first substrate66and the mounted components mounted on the first substrate66, to the bearing holder40. The bearing holder40dissipates the heat transmitted from the heat dissipation grease G to the outside. That is, according to the present embodiment, the bearing holder40can function as a heat sink. It is preferable that the bearing holder40is made of a material having high heat conduction efficiency. It is preferable that the bearing holder40is made of an aluminum alloy, for example. The heat dissipation grease G preferably has insulation property. As a result, the heat dissipation grease can suppress discharge between the first substrate66and the bearing holder40. As the material of the bearing holder40, aluminum, copper, a copper alloy, SUS, or the like may also be used, besides the aluminum alloy.

The bearing holder40is provided with a through hole45penetrating in the vertical direction. The through hole45is positioned substantially at the center of the bearing holder40. The upper end portion of the shaft21is disposed inside the through hole45. On the inner peripheral surface of the through hole45, a downward step surface45ais provided. The through hole45accommodates the upper-side bearing24in a region below the downward step surface45a. The upper surface of the outer ring of the upper-side bearing24is in contact with the downward step surface45avia a wave washer46. Further, the opening on the upper side of the through hole45is covered with the lid70. The lid70is fitted and fixed to the through hole45. The lid70can suppress the heat dissipation grease G from entering into the through hole45.

The first substrate66and the second substrate67control the motor1. That is, the motor1includes the control device4that is configured of the first substrate66and the second substrate67and controls rotation of the shaft21. On the first substrate66and the second substrate67, electronic components are mounted. The electronic components mounted on the first substrate66and the second substrate67include a rotation sensor61, an electrolytic capacitor, a choke coil, and the like.

The first substrate66is disposed on the upper side (+z side) of the bearing holder40. The second substrate67is disposed on the upper side of the first substrate66. The plate surface directions of both the first substrate66and the second substrate67are perpendicular to the axial direction. The first substrate66and the second substrate67are disposed so as to overlap with each other as seen in the axial direction. That is, the first substrate66and the second substrate67are stacked along the axial direction with a predetermined gap therebetween.

The first substrate66has the lower surface66aand the upper surface66b. Similarly, the second substrate67has the lower surface67aand the upper surface67b. The upper surface66bof the first substrate66and the lower surface67aof the second substrate67face each other in the vertical direction with a gap therebetween. The lower surface66aof the first substrate66and the upper surface40aof the bearing holder40face each other in the vertical direction with a gap therebetween. That is, the first substrate66is disposed on the upper side of the bearing holder40with a gap therebetween. The gap between the lower surface66aof the first substrate66and the upper surface40aof the bearing holder40is filled with the heat dissipation grease G.

On the lower surface66aof the first substrate66, the rotation sensor61is mounted. Further, the rotation sensor61is disposed so as to overlap the sensor magnet63of the first substrate66when viewed from the axial direction. The rotation sensor61detects rotation of the sensor magnet63. In the present embodiment, the rotation sensor61is a magneto-resistive element. The rotation sensor61may be another sensor such as a Hall element, for example.

FIG. 4is an exploded view of the motor1. InFIG. 4, illustration of the respective mounted components mounted on the substrate housing12, the first substrate66, and the second substrate67is omitted. As shown inFIG. 4, the first substrate66and the second substrate67are electrically connected by a plurality of connection pins51. The first substrate66and the second substrate67constitute a substrate assembly68.

As shown inFIG. 1, the first substrate66and the second substrate67are provided with a plurality of holes66cand67cpenetrating in the vertical direction respectively. The hole66cof the first substrate66and the hole67cof the second substrate67are disposed so as to overlap each other as seen in the axial direction. The hole66cof the first substrate66and the hole67cof the second substrate67are connected by the connection pin51.

The control device4has the first substrate66and the second substrate67stacked along the vertical direction (axial direction). In addition, the first substrate66is electrically connected to the second substrate (another substrate) disposed on the upper side, by the connection pin51. According to the control device4of the present embodiment, with a plurality of substrates (the first substrate66and the second substrate67) electrically connected to each other, it is possible to select mounted components to be mounted on each substrate according to the thermal characteristics. In the present embodiment, the first substrate is in thermal contact with the bearing holder40having a function as a heat sink via the heat dissipation grease G. Therefore, the first substrate66has higher heat dissipation efficiency than that of the second substrate67. In the case of mounting mounted components that are likely to generate heat on the first substrate66, it is possible to provide the motor1having excellent heat dissipation characteristics as a whole. In addition, it is possible to mount mounted components that are likely to generate heat on the second substrate67, and to mount mounted components that are susceptible to heat on the first substrate66. In that case, it is possible to make it difficult for the mounted components of the first substrate66to be affected by heat.

As shown inFIG. 1, the connection pin51extends along the axial direction (vertical direction) between the hole66cof the first substrate66and the hole67cof the second substrate67. The connection pin51has a first tip portion51alocated on the lower side and a second tip portion51blocated on the upper side. The first tip portion51ais inserted into the hole66cof the first substrate66from the upper surface66bside, and is connected to the first substrate66. The second tip portion51bis inserted into the hole67cof the second substrate67from the lower surface67aside, and is connected to the second substrate67.

The connection between the first tip portion51aand the hole66cof the first substrate66and the connection between the second tip portion51band the hole67cof the second substrate67are so-called press-fit connection. The first tip portion51ais slightly wider than the hole66c. The first tip portion51ais press-fitted into the hole66c. As a result, a mechanical contact load is generated between the first tip portion51aand the hole66c, and the first tip portion51aand the hole66care electrically connected to each other. Similarly, the second tip portion51bis slightly wider than the hole67c, and the second tip portion51band the hole67care electrically connected to each other by a mechanical contact load.

According to the present embodiment, the first substrate and the second substrate67are connected by press-fit connection via the connection pins51. When press-fit connection is adopted, solder is not needed between the connection pin51and the first substrate66and between the connection pin51and the second substrate67. In addition, since the process of press-fitting the connection pin51into the hole66c(or the hole67c) can be performed simultaneously for a plurality of the connection pins51, it can be completed in a short time. Thereby, it is possible to simplify the manufacturing process, to reduce the manufacturing cost, and to provide inexpensive control device4and inexpensive motor1.

As shown inFIG. 4, the connection pins51are classified into a first connection pin group (first wiring group)56A and a second connection pin group (second wiring group)56B. The first connection pin group56A and the second connection pin group56B are positioned at opposite sides in the radial direction across the center axis J. The connection pins51of the first connection pin group56A and the second connection pin group56B are arranged side by side in a plurality of rows and columns.

The control device4of the present embodiment has control circuits of two systems or the like. In the present embodiment, the control device4includes two mounted components that perform the same function and two control circuits connecting the mounted components. As a result, the redundancy of the control device4is enhanced. That is, even if any trouble occurs in the control circuit of one system, the control device4can continue driving of the motor1by the control circuit of the other system. The first connection pin group56A serves as a part of one of the control circuits of the two systems, and the second connection pin group56B serves as a part of the other control circuit. That is, the first substrate66and the second substrate67are electrically connected by the connection pins51of the two systems. Even if the control circuit or the like of the one system fails, as long as the motor can be driven by the other control circuit, the two control circuits in the control device4do not necessarily have the same function. At least a part of the functions thereof may be different. Further, the two control circuits may not necessarily have two mounted components that perform the same function.

The spacer80is made of an insulating material. The spacer80is interposed between the bearing holder40and the first substrate66. The spacer80is inserted into the housing concavity41. The spacer80is fixed to the bearing holder40by means of adhesion or the like.

As shown inFIG. 2, the spacer80has a bottom wall portion82, a side wall portion81, and a flange portion83. The bottom wall portion82and the side wall portion81cover the inner surface of the housing concavity41. In addition, the spacer80constitutes a box body opened upward by the bottom wall portion82and the side wall portion81. The bottom wall portion82and the side wall portion81are covered with the spacer80. Inside the spacer80, the first tip portion51aof the connection pin51, protruding from the lower surface66aof the first substrate66, is accommodated. That is, the first tip portion51aprotruding from the lower surface66ais accommodated in the housing concavity41via the spacer80.

As shown inFIG. 4, the bearing holder40has the pair of housing concavities41, and the spacers80are inserted in the respective housing concavities41. Further, the first connection pin group56A is inserted in one of the pair of spacers80, and the second connection pin group56B is connected to the other. That is, the first tip portions51aof the connection pins51(the first connection pin group56A) constituting one system and the first tip portions51aof the connection pins51(the second connection pin group56B) are disposed so as to be surrounded by side wall portions81of different spacers80, respectively.

As shown inFIG. 2, according to the present embodiment, the first tip portion51aprotruding from the lower surface66aof the first substrate66is accommodated in the housing concavity41provided to the upper surface40aof the bearing holder40. Therefore, according to the present embodiment, the first tip portion51aand the bearing holder40can be spaced apart from each other in the vertical direction without increasing the distance between the upper surface40aof the bearing holder40and the lower surface66aof the first substrate66. As a result, it is possible to reduce the vertical dimension of the control device4and the motor1having the control device4.

According to the present embodiment, the inner surface of the housing concavity41is covered with the spacer80made of an insulating material. In general, insulating materials have better insulation property than that of the air at atmospheric pressure. Therefore, by providing the spacer80, it is possible to bring the first tip portion51aand the inner surface of the housing concavity41close to each other while securing the insulation property, as compared with the case where the spacer80is not provided. It is possible to reduce the dimension of the housing concavity41in the vertical direction and the direction orthogonal to the vertical direction, and as a result, it is possible to reduce the dimension of the control device4and the motor1having the control device4.

The bottom wall portion82has a substantially rectangular shape in a plan view. Further, as shown inFIG. 2, the bottom wall portion82is disposed along the bottom surface of the housing concavity41. A gap is provided between the bottom wall portion82and the housing concavity41. The bottom wall portion82is positioned between the first tip portion51aof the connection pin51and the bearing holder40, along the vertical direction. The bottom wall portion82secures insulation property in the vertical direction of the first tip portion51aand the bearing holder40. Since the bottom wall portion82is provided, the vertical dimension of the control device4can be reduced.

The side wall portion81extends upward from the peripheral edge of the bottom wall portion82. The side wall portion81is disposed along the inner side surface of the housing concavity41. The height dimension of the side wall portion81is smaller than the depth dimension of the housing concavity41. The side wall portion81collectively encloses the first tip portions51aof the connection pins51in a plan view. The side wall portion81ensures insulation property between the first tip portion51aand the side wall portion of the housing concavity41. By providing the side wall portion81, it is possible to reduce the dimension (radial dimension) in the direction orthogonal to the vertical direction of the control device4.

The flange portion83is located at the upper end of the side wall portion81. The flange portion83is interposed between the bearing holder40and the first substrate66. That is, the spacer80is in contact with both the facing surfaces (the upper surface40aand the lower surface66a) of the bearing holder40and the first substrate66in the flange portion83.

The flange portion83defines the vertical position of the first substrate66with respect to the bearing holder40. Since the height dimension of the side wall portion81is smaller than the depth dimension of the housing concavity41as described above, there is a gap between the bottom wall portion82and the housing concavity41. Therefore, by precisely managing the thickness of the flange portion83, it is possible to precisely position the first substrate66without strictly controlling the dimension in the height direction of the side wall portion81.

The flange portion83is disposed so as to surround the first connection pin group56A (or the second connection pin group56B). Further, the flange portion83is in contact with the mutually facing surfaces of the bearing holder40and the first substrate66. The flange portion83receives a force when the connection pin51is press-fitted into the hole66cof the first substrate66, to thereby be able to reduce the load on the first substrate66.

FIG. 5is a cross-sectional view of a spacer180according to a modification that can be adopted in the above-described embodiment.FIG. 6is a cross-sectional view taken along line VI-VI inFIG. 5. Note that members or portions that have their equivalents in the above-described embodiment are denoted by the same reference numerals as those of their equivalents in the above-described embodiment, and descriptions of those members or portions are omitted.

The spacer180has a bottom wall portion182, a side wall portion181, a partition wall portion184, and a flange portion183. The bottom wall portion182is disposed along the bottom surface of the housing concavity41. The side wall portion181extends upward from the bottom surface of the bottom wall portion182. The side wall portion181is disposed along the inner side surface of the housing concavity41. The bottom wall portion182and the side wall portion181constitute a box body which opens upward. The partition wall portion184extends upward from the bottom wall portion182. The partition wall portion184has a cross shape in a plan view. The partition wall portion184partitions the inside of the side wall portion181into a plurality of regions in a plan view. The height of the upper surface of the partition wall portion184is equal to the height of the upper surface of the flange portion183. The flange portion183is located at the upper end of the side wall portion181. The flange portion183is interposed between the bearing holder40and the first substrate66.

As shown inFIG. 6, the first tip portion51aof one connection pin51is accommodated in each of the regions defined by the partition wall portion184and the side wall portion181.

According to the present modification, since the first tip portions51aof the connection pins51are disposed in the regions partitioned by the partition wall portions184, it is possible to ensure the insulation property between the first tip portions51a. In addition, the partition wall portion184functions as a rib for reinforcing the spacer180. In addition, the partition wall portion184receives a force when the connection pin51is press-fitted into the hole66cof the first substrate66, to thereby be able to reduce the load on the first substrate66more effectively.

In the present embodiment, the following configuration may be adopted. In the present embodiment, the case where the first tip portion51ais connected to the first substrate66by press-fitting using the connection pin51as the wiring has been exemplified. However, as a wiring, a bending conductive wire may be adopted. In that case, the tip portion (corresponding to the first tip portion51a) of the wiring can be inserted from the upper surface66binto the hole66cof the first substrate66and connected by soldering on the lower surface66aside. Even in that case, the spacer80has an effect of ensuring insulation property between the tip portion of the wiring and the bearing holder40.

In the present embodiment, the case where the first substrate66is connected to the second substrate67via the connection pin51has been exemplified. However, an external device may be connected to the first substrate66via wiring (corresponding to the connection pin51).

In the present embodiment, the case where the spacer80has the flange portion83having a shape along the opening peripheral edge of the housing concavity41has been described. However, as shown inFIG. 4, the flange portion83may have an extension portion85extending along the circumferential direction of the center axis J. The extension portion85is interposed between the bearing holder40and the first substrate66. In the case where the extension portion85is provided, the flange portion83can define a gap (vertical distance) between the bearing holder40and the first substrate66in a wide range. The extension portions85of the pair of spacers80, disposed opposite to each other across the center axis J, may be integrally connected along the circumferential direction of the center axis J. Further, the extension portion85may have a through hole for inserting a screw, and may be screwed to the bearing holder40together with the first substrate66.

Next, an embodiment of an apparatus on which the motor1of the present embodiment is mounted will be described. In the present embodiment, an example in which the motor1is mounted on an electric power steering apparatus will be described.FIG. 7is a schematic diagram showing an electric power steering apparatus2of the present embodiment.

The electric power steering apparatus2is mounted on a wheel steering mechanism of an automobile. The electric power steering apparatus2is an apparatus that reduces the steering force by hydraulic pressure. As shown inFIG. 7, the electric power steering apparatus2of the present embodiment includes the motor1, a steering shaft114, an oil pump116, and a control valve117.

The steering shaft114transmits the input from a steering wheel111to an axle113having wheels112. The oil pump116generates a hydraulic pressure in a power cylinder115that transmits a hydraulic driving force to the axle113. The control valve117controls the oil of the oil pump116. In the electric power steering apparatus2, the motor1is mounted as a drive source of the oil pump116.

Since the electric power steering apparatus2of the present embodiment includes the motor1of the present embodiment, the electric power steering apparatus2that exhibits the same effect as that of the above-described motor1is obtained.