CN217115843U - Electric Actuator - Google Patents

Abstract

The utility model provides an electric actuator, this electric actuator possess: a motor unit having a motor shaft that rotates about a central axis; a transmission mechanism connected to the motor shaft; an output shaft that rotates about an output axis parallel to the central axis, and to which power of the motor shaft is transmitted via a transmission mechanism; a first housing member that rotatably supports the motor shaft and the output shaft from one axial side; and a second housing part rotatably supporting the motor shaft and the output shaft from the other axial side. The first housing member is provided with a first positioning portion, the second housing member is provided with a second positioning portion, the first housing member and the second housing member are fixed in a state where the first positioning portion and the second positioning portion overlap each other when viewed from the axial direction, and the output shaft is arranged on an imaginary straight line passing through the central axis, the first positioning portion, and the second positioning portion when viewed from the axial direction.

Description

Electric Actuator

technical field

The utility model relates to an electric actuator.

Background technique

There is known a shift-by-wire system in which a rotary actuator is driven and controlled according to a gear position selected by a driver, thereby switching the gear position of an automatic transmission. As an actuator used in a shift-by-wire system, Patent Document 1 discloses a rotary actuator including a motor, a speed reducer, an output shaft, and a housing that accommodates them.

Patent Document 1: Japanese Patent Laid-Open No. 2018-194087

The casing of the actuator of Patent Document 1 has a front casing and a rear casing fastened to each other in the axial direction. The front case and the rear case rotatably support the input side and the output shaft from both sides in the axial direction, respectively. In such a structure, even if the coaxiality of the input shafts of the front casing and the rear casing is ensured, the positional deviation of the output shaft cannot be eliminated, and there is a problem that the rotational efficiency of the output shaft decreases.

Utility model content

In view of the above-mentioned circumstances, one of the objects of the present invention is to provide an electric actuator capable of improving the rotational efficiency of the output shaft.

According to one aspect of the electric actuator of the present invention, the electric actuator includes: a motor part having a motor shaft that rotates about a central axis; a transmission mechanism connected to the motor shaft; and an output shaft Rotating around an output axis parallel to the central axis, to which the power of the motor shaft is transmitted via the transmission mechanism; and a first housing member connecting the motor shaft and the An output shaft is rotatably supported; and a second housing member rotatably supports the motor shaft and the output shaft from the other side in the axial direction. A first positioning portion is provided on the first housing member. A second positioning portion is provided on the second housing member. The first housing member and the second housing member are fixed in a state in which the first positioning portion and the second positioning portion overlap each other when viewed from the axial direction. The output shaft is disposed on an imaginary straight line passing through the central axis, the first positioning portion, and the second positioning portion when viewed from the axial direction.

In the electric actuator of the above aspect, the first positioning portion and the second positioning portion have mirror-symmetrical shapes with respect to the imaginary straight line, respectively.

In the electric actuator of the above aspect, the first positioning portion has a notch shape extending inward from the outer edge of the first housing member when viewed in the axial direction, and the second positioning portion is in the axial direction. It is in the shape of a notch extending inward from the outer edge of the second housing member when viewed.

According to one aspect of the present invention, the rotational efficiency of the output shaft of the electric actuator can be improved.

Description of drawings

FIG. 1 is a cross-sectional view of an electric actuator according to an embodiment.

FIG. 2 is a perspective view of an electric actuator according to an embodiment.

FIG. 3 is a plan view viewed from the lower side of the electric actuator according to the embodiment.

4 is a perspective view of a first notch portion and a second notch portion and a jig inserted into the first notch portion and the second notch portion in an assembly process according to an embodiment.

Label description

9: jig; 9a: first jig piece; 9b: second jig piece; 10: electric actuator; 11: housing; 12: first housing member; 14: second housing member; 40: motor part ; 41: motor shaft; 50: reduction mechanism (transmission mechanism); 61: output shaft; 71: first cutout portion (first positioning portion); 72: second cutout portion (second positioning portion); J1: center axis; J3: output axis; VL: imaginary straight line.

Detailed ways

The Z-axis appropriately shown in each figure represents the up-down direction. The positive side (+Z side) of the Z axis is the upper side, and the negative side (-Z side) of the Z axis is the lower side. In the following description, the direction parallel to the Z axis is referred to as the "up-down direction Z". In addition, the X-axis and the Y-axis which are shown suitably in each figure each represent one of the horizontal directions perpendicular|vertical to the up-down direction Z. The X and Y axes are perpendicular to each other. In the following description, the direction parallel to the X axis is referred to as "first horizontal direction X", and the direction parallel to the Y axis is referred to as "second horizontal direction Y". In addition, the positive side (+X side) of the X-axis is referred to as "one side in the first horizontal direction X", and the negative side (-X side) of the X-axis is referred to as "the other side in the first horizontal direction X" . The positive side (+Y side) of the Y axis is referred to as "one side in the second horizontal direction Y", and the negative side (-Y side) of the Y axis is referred to as "the other side in the second horizontal direction Y". In this embodiment, the vertical direction Z corresponds to the predetermined direction, the lower side corresponds to one side of the predetermined direction, and the upper side corresponds to the other side of the predetermined direction.

In addition, the vertical direction, the horizontal direction, the upper side, and the lower side are only names for explaining the relative positional relationship of each part, and the actual arrangement relationship and the like may be an arrangement relationship other than the arrangement relationship and the like indicated by these names. .

＜Electric Actuator＞

FIG. 1 is a cross-sectional view of an electric actuator 10 according to the present embodiment.

The electric actuator 10 of the present embodiment is mounted on a vehicle. More specifically, the electric actuator 10 is mounted on, for example, a park-by-wire actuator device that is driven in accordance with a shift operation by a driver of the vehicle. The electric actuator 10 includes a motor unit 40 , a speed reduction mechanism (transmission mechanism) 50 , an output unit 60 , a housing 11 , a bus bar unit 90 , a circuit board 70 , a motor unit sensor 8 , an output unit sensor 7 , and a partition member 80 .

Hereinafter, each part of the electric actuator 10 will be described based on the posture of the electric actuator 10 in the assembly process. Specifically, each part of the electric actuator 10 will be described with respect to the case where the central axis J1 of the motor portion 40 is arranged in parallel with the vertical direction Z. In addition, the posture of the electric actuator 10 when mounted on a vehicle is not particularly limited, and is not limited by names such as the vertical direction Z used in the following description.

The central axis J1 of the motor portion 40 is appropriately shown by a dashed-dotted line in each drawing. In the present embodiment, the central axis J1 extends in the vertical direction Z. In other words, in the following description, the vertical direction Z is the axial direction of the central axis J1. In the following description, unless otherwise specified, the radial direction centered on the central axis J1 is simply referred to as a “radial direction”, and the circumferential direction centered on the central axis J1 is simply referred to as a “circumferential direction”.

The motor unit 40 includes a rotor 40 a , a first bearing 44 a , a second bearing 44 b , a third bearing 44 c , a fourth bearing 44 d , a stator 43 , a magnet holder 46 , a first sensor magnet 45 , and a nut 48 . That is, the electric actuator 10 includes a rotor 40a, a first bearing 44a, a second bearing 44b, a third bearing 44c, a fourth bearing 44d, a stator 43, a magnet holder 46, a first sensor magnet 45, and a nut 48. In the present embodiment, the first bearing 44a, the second bearing 44b, the third bearing 44c, and the fourth bearing 44d are, for example, ball bearings.

The rotor 40a rotates around a central axis J1 extending in the vertical direction Z as a center. The rotor 40a has a motor shaft 41 and a rotor main body 42 . That is, the motor part 40 has the motor shaft 41 and the rotor main body 42 . The motor shaft 41 extends in the vertical direction Z. The motor shaft 41 is rotatable about the central axis J1. The motor shaft 41 has an eccentric shaft portion 41a centered on an eccentric axis J2 that is eccentric with respect to the central axis J1. In the present embodiment, the eccentric shaft portion 41 a is a part of the lower portion of the motor shaft 41 . A third bearing 44c is fixed to the eccentric shaft portion 41a. The eccentric axis J2 is parallel to the central axis J1. The eccentric shaft portion 41a has a cylindrical shape extending around the eccentric axis J2. The portion other than the eccentric shaft portion 41a of the motor shaft 41 is in the shape of a column extending around the central axis J1.

As shown in FIGS. 2 and 3 , the motor shaft 41 has a small diameter portion 41b, a middle diameter portion 41c, and a large diameter portion 41g. In the present embodiment, the small-diameter portion 41 b , the middle-diameter portion 41 c , and the large-diameter portion 41 g are part of the upper portion of the motor shaft 41 .

The small diameter portion 41b is located above the large diameter portion 41g. In the present embodiment, the small-diameter portion 41 b is the portion located on the uppermost side of the motor shaft 41 . The upper end of the small diameter portion 41 b is the upper end of the motor shaft 41 . The outer peripheral surface of the small diameter portion 41b is provided with a screw portion to which the nut 48 is fastened.

The small diameter portion 41b has a central recessed portion 41i which is recessed from the upper end portion of the small diameter portion 41b to the lower side, and the central axis J1 passes through the central recessed portion 41i. When viewed from the upper side, the inner edge of the central recessed portion 41i has a circular shape centered on the central axis J1. The inner surface of the central recessed portion 41i is a tapered surface with the center axis J1 as the center, and the inner diameter decreases toward the lower side. The central concave portion 41i is, for example, a center hole produced when machining the motor shaft 41 using a lathe.

The middle-diameter portion 41c is connected to the lower side of the small-diameter portion 41b via a step. The outer diameter of the middle diameter portion 41c is larger than the outer diameter of the small diameter portion 41b. The first bearing 44a is fixed to the middle diameter portion 41c. More specifically, the inner ring of the first bearing 44a is fitted and fixed to the middle diameter portion 41c. The upper end of the middle diameter portion 41c is positioned above the first bearing 44a.

The large-diameter portion 41g is connected to the lower side of the middle-diameter portion 41c via a step. The outer diameter of the large diameter portion 41g is larger than the outer diameter of the middle diameter portion 41c. The large diameter portion 41 g is a portion of the motor shaft 41 to which the rotor body 42 is fixed. The rotor main body 42 is fixed to the outer peripheral surface of the large diameter portion 41g. The upper end portion of the large diameter portion 41g supports the inner ring of the first bearing 44a fixed to the middle diameter portion 41c from the lower side.

The first bearing 44 a , the second bearing 44 b , the third bearing 44 c , and the fourth bearing 44 d are fixed to the motor shaft 41 . The first bearing 44a and the second bearing 44b support the motor shaft 41 so as to be rotatable about the central axis J1. The first bearing 44a is a bearing that rotatably supports a portion of the motor shaft 41 positioned above the large diameter portion 41g. In the present embodiment, the first bearing 44a is a bearing that rotatably supports the intermediate diameter portion 41c. The second bearing 44b is a bearing that rotatably supports a portion of the motor shaft 41 positioned below the large diameter portion 41g. In the present embodiment, the second bearing 44b is a bearing that rotatably supports the lower end portion of the motor shaft 41 .

The rotor body 42 is fixed to the motor shaft 41 . More specifically, the rotor main body 42 is fixed to the large diameter portion 41g. The rotor main body 42 has a rotor iron core 42a fixed to the motor shaft 41 and a rotor magnet 42b fixed to an outer peripheral portion of the rotor iron core 42a. Although illustration is omitted, in this embodiment, a plurality of rotor magnets 42b are provided at intervals in the circumferential direction.

The stator 43 is located radially outside the rotor 40a. More specifically, the stator 43 is arranged radially outward of the rotor main body 42 with a gap therebetween. The stator 43 is an annular shape surrounding the radially outer side of the rotor main body 42 . The stator 43 has, for example, a stator core 43a, an insulator 43b, and a plurality of coils 43c. The respective coils 43c are attached to the teeth of the stator core 43a via the insulator 43b.

The magnet holder 46 is fixed to a portion of the motor shaft 41 positioned above the large-diameter portion 41g. The magnet holder 46 has a substantially disk shape centered on the central axis J1. The magnet holder 46 is produced by, for example, pressing a metal plate member. The magnet holder 46 is fixed to the motor shaft 41 with a nut 48 .

The first sensor magnet 45 is fixed to the magnet holder 46 . The first sensor magnet 45 has a ring shape surrounding the motor shaft 41 when viewed in the vertical direction Z. The first sensor magnet 45 is, for example, an annular shape centered on the central axis J1. The first sensor magnet 45 is, for example, a plate shape whose plate surface faces the vertical direction Z. The plate surface of the first sensor magnet 45 is perpendicular to the vertical direction Z, for example. The first sensor magnet 45 is provided so that N poles and S poles alternate in the circumferential direction. The magnetic field of the first sensor magnet 45 is detected by the motor unit sensor 8 .

The speed reduction mechanism 50 is located on the lower side of the motor unit 40 . The speed reduction mechanism 50 is connected to the motor shaft 41 . A partition member 80 is arranged between the speed reduction mechanism 50 and the stator 43 in the vertical direction Z. The speed reduction mechanism 50 is arranged below the rotor main body 42 and the stator 43 . The speed reduction mechanism 50 includes an external gear 51 , an internal gear 52 , an output gear 53 , and a plurality of protrusions 54 .

The externally toothed gear 51 is in the shape of an annular plate that expands in the radial direction of the eccentric axis J2 centered on the eccentric axis J2 of the eccentric shaft portion 41a. The radially outer surface of the externally toothed gear 51 is provided with a gear portion 51b. The gear portion 51 b of the externally-toothed gear 51 has a plurality of toothed portions arranged along the outer circumference of the externally-toothed gear 51 .

The externally toothed gear 51 is connected to the motor shaft 41 . More specifically, the externally toothed gear 51 is connected to the eccentric shaft portion 41a of the motor shaft 41 via the third bearing 44c. Thereby, the speed reduction mechanism 50 is connected to the motor shaft 41 . The externally toothed gear 51 is fitted to the outer ring of the third bearing 44c from the radially outer side. Thereby, the third bearing 44c connects the motor shaft 41 and the externally toothed gear 51 so as to be relatively rotatable about the eccentric axis J2.

In the present embodiment, the externally toothed gear 51 has a plurality of hole portions 51a. In the present embodiment, the hole portion 51a penetrates the externally toothed gear 51 in the vertical direction Z. As shown in FIG. The plurality of hole portions 51a are arranged in the circumferential direction. More specifically, the plurality of hole portions 51a are arranged at equal intervals over the entire circumference along the circumferential direction centered on the eccentric axis J2. The hole portion 51a has a circular shape when viewed in the vertical direction Z. The inner diameter of the hole portion 51 a is larger than the outer diameter of the protruding portion 54 . In addition, the hole portion 51a may be a hole having a bottom.

The internally-toothed gear 52 is located radially outside the externally-toothed gear 51 , and is an annular shape surrounding the externally-toothed gear 51 . In the present embodiment, the internally toothed gear 52 is an annular shape centered on the central axis J1. The internal gear 52 is fixed to the casing 11. The internal gear 52 meshes with the external gear 51 .

The output gear 53 is arranged above the external gear 51 and the internal gear 52 . That is, the output gear 53 is arranged so as to overlap with the externally toothed gear 51 when viewed in the vertical direction Z. As shown in FIG. The output gear 53 is connected to the motor shaft 41 via the fourth bearing 44d. The output gear 53 is, for example, an annular shape centered on the central axis J1 when viewed in the vertical direction Z. A gear portion 53 a is provided on the radially outer surface of the output gear 53 . The gear portion 53 a has a plurality of tooth portions arranged along the outer circumference of the output gear 53 . The tooth part of the gear part 53a of the output gear 53 meshes with the tooth part of the gear part 62a of the drive gear 62 mentioned later.

The inner peripheral edge part of the output gear 53 is arrange|positioned so that it may oppose the lower side of the retaining ring 49 attached to the outer ring of the 4th bearing 44d. The retaining ring 49 protrudes radially outward from the fourth bearing 44d. The output gear 53 is restrained from moving upward with respect to the fourth bearing 44d by the retaining ring 49 .

The plurality of protrusions 54 protrude in the vertical direction Z from the output gear 53 toward the externally toothed gear 51 . The plurality of protrusions 54 have a cylindrical shape protruding downward from the lower surface of the output gear 53. In the present embodiment, the plurality of protrusions 54 are integrally formed with the output gear 53 . The plurality of protrusions 54 are arranged at equal intervals over the entire circumference in the circumferential direction.

The outer diameter of the protruding portion 54 is smaller than the inner diameter of the hole portion 51a. The plurality of protruding portions 54 are respectively inserted into the plurality of hole portions 51a from the upper side. The outer peripheral surface of the protruding portion 54 is inscribed with the inner surface of the hole portion 51a. The plurality of protruding portions 54 support the externally toothed gear 51 through the inner surface of the hole portion 51a so as to be able to swing about the central axis J1. As described above, in the present embodiment, since the upward movement of the output gear 53 is suppressed by the retaining ring 49, the protrusion 54 provided on the output gear 53 is suppressed from being pulled upward from the hole 51a.

The output unit 60 is a portion that outputs the driving force of the electric actuator 10 . The output unit 60 is arranged radially outside the motor unit 40 . The output unit 60 includes an output shaft 61 , a drive gear 62 , a sliding bearing 65 , a second sensor magnet 63 , and a magnet holder 64 . That is, the electric actuator 10 includes the output shaft 61 , the drive gear 62 , the sliding bearing 65 , the second sensor magnet 63 , and the magnet holder 64 .

The output shaft 61 has a cylindrical shape extending in the vertical direction Z of the motor shaft 41 . In this way, since the output shaft 61 extends in the same direction as the motor shaft 41, the structure of the reduction mechanism 50 that transmits the rotation of the motor shaft 41 to the output shaft 61 can be simplified. The output shaft 61 is connected to the motor shaft 41 via the speed reduction mechanism 50 . In the present embodiment, the output shaft 61 has a cylindrical shape centered on the output axis J3 which is parallel to the central axis J1.

The output axis J3 is the central axis of the output shaft 61 . The output axis J3 is parallel to the center axis J1, and is arranged radially away from the center axis J1. That is, the motor shaft 41 and the output shaft 61 are arranged apart from each other in the direction perpendicular to the vertical direction Z. In other words, the motor shaft 41 and the output shaft 61 are arranged apart from each other in the radial direction of the motor shaft 41 . Therefore, compared with the case where the motor shaft 41 and the output shaft 61 are arranged side by side in the vertical direction Z, the size of the electric actuator 10 in the vertical direction Z can be reduced. In Fig. 1 , the output axis J3 is located, for example, to the right of the central axis J1. In addition, the radial direction centering on the output axis J3 is called "output radial direction". The output radial direction is the radial direction of the output shaft 61 .

The output shaft 61 is opened on the lower side. The output shaft 61 has a spline groove on the inner peripheral surface. The output shaft 61 is arranged at a position overlapping the rotor main body 42 in the radial direction of the motor shaft 41 . A lower portion of the output shaft 61 is provided with a shaft flange portion 61b. The shaft flange portion 61b protrudes outward in the output radial direction. The shaft flange portion 61b has an annular shape centered on the output axis J3.

The driven shaft DS is inserted into the output shaft 61 from the lower side, and is coupled to the output shaft 61 . More specifically, the output shaft 61 and the driven shaft DS are connected by fitting the spline portion provided on the outer peripheral surface of the driven shaft DS with the spline groove provided on the inner peripheral surface of the output shaft 61 . The driving force of the electric actuator 10 is transmitted to the driven shaft DS via the output shaft 61 . Thereby, the electric actuator 10 rotates the driven shaft DS around the output axis J3.

The drive gear 62 is fixed to the output shaft 61 . The drive gear 62 extends from the output shaft 61 toward the output gear 53 . The drive gear 62 meshes with the output gear 53 . Although not shown, the drive gear 62 has a substantially fan shape when viewed in the vertical direction Z, for example. The dimension of the drive gear 62 in the circumferential direction centered on the output axis J3 increases toward the outer side in the output radial direction. The drive gear 62 has a gear portion at an outer end portion in the output radial direction. The gear portion 62a of the drive gear 62 has a plurality of tooth portions arranged in the circumferential direction centered on the output axis J3. The drive gear 62 meshes with the output gear 53. Thereby, the drive gear 62 is connected to the speed reduction mechanism 50 . The rotation of the motor unit 40 is transmitted to the drive gear 62 via the reduction mechanism 50 .

The magnet holder 64 is a substantially cylindrical member extending in the vertical direction Z with the output axis J3 as the center. The magnet holder 64 is open on both sides in the vertical direction Z. As shown in FIG. The magnet holder 64 is fixed to the upper part of the output shaft 61 . In the present embodiment, the magnet holder 64 is arranged on the radially outer side of the first bearing 44 a of the motor unit 40 . When viewed in the vertical direction Z, the magnet holder 64 partially overlaps with the circuit board 70 . The magnet holder 64 is arranged below the circuit board 70 . The output shaft 61 is press-fitted into the inner side of the magnet holder 64 .

The second sensor magnet 63 has an annular shape centered on the output axis J3. The second sensor magnet 63 is fitted to the upper end of the magnet holder 64 . The second sensor magnet 63 is fixed to the magnet holder 64 by, for example, an adhesive. The magnet holder 64 is fixed to the output shaft 61 , whereby the second sensor magnet 63 is fixed to the output shaft 61 via the magnet holder 64 . A part of the second sensor magnet 63 faces the lower surface of the circuit board 70 with a gap therebetween.

The upper end of the output shaft 61 is positioned lower than the upper end of the magnet holder 64 . The upper end portion of the output shaft 61 is provided with an operation portion 66 into which a tool can be fitted. The operation portion 66 is, for example, a hole portion recessed downward from the upper end portion of the output shaft 61. The shape of the operation portion 66 is, for example, a square or a regular hexagon centered on the output axis J3 when viewed in the vertical direction Z.

When the motor shaft 41 rotates around the central axis J1, the eccentric shaft portion 41a revolves around the central axis J1 in the circumferential direction. The revolution of the eccentric shaft portion 41a is transmitted to the externally toothed gear 51 via the third bearing 44c, and the externally toothed gear 51 swings while the position inscribed between the inner peripheral surface of the hole portion 51a and the outer peripheral surface of the protruding portion 54 is changed. Thereby, the position where the gear portion of the externally-toothed gear 51 meshes with the gear portion of the internally-toothed gear 52 changes in the circumferential direction. Therefore, the rotational force of the motor shaft 41 is transmitted to the internally toothed gear 52 via the externally toothed gear 51.

Here, in the present embodiment, the internally-toothed gear 52 does not rotate due to the second casing member 14 which is fixed to the casing 11, which will be described later. Therefore, the externally-toothed gear 51 is rotated about the eccentric axis J2 by the reaction force of the rotational force transmitted to the internally-toothed gear 52 . At this time, the direction in which the externally toothed gear 51 rotates is opposite to the direction in which the motor shaft 41 rotates. The rotation of the externally toothed gear 51 around the eccentric axis J2 is transmitted to the output gear 53 via the hole portion 51 a and the protruding portion 54 . Thereby, the output gear 53 rotates around the center axis J1. The rotation of the motor shaft 41 is decelerated and transmitted to the output gear 53.

When the output gear 53 rotates, the drive gear 62 meshed with the output gear 53 rotates about the output axis J3. Thereby, the output shaft 61 fixed to the drive gear 62 rotates around the output axis J3. In this way, the rotation of the motor unit 40 is transmitted to the output shaft 61 via the speed reduction mechanism 50 . That is, the power of the motor shaft 41 is transmitted to the output shaft 61 via the speed reduction mechanism 50, and the output shaft 61 rotates around the output axis J3. According to such a configuration of the speed reduction mechanism 50 , the rotation of the output shaft 61 can be relatively greatly reduced with respect to the rotation of the motor shaft 41 . Therefore, the rotational torque of the output shaft 61 can be made relatively large. Therefore, it is easy to secure the output of the electric actuator 10 while reducing the size of the electric actuator 10 . In the electric actuator 10 of the present embodiment, the output shaft 61 rotates in both directions within a range of less than one rotation.

The housing 11 accommodates the motor unit 40 , the speed reduction mechanism 50 , the output unit 60 including the output shaft 61 , the circuit board 70 , the bus bar unit 90 , and the partition member 80 . The casing 11 has a first casing member 12 , a cover member 13 and a second casing member 14 . That is, the electric actuator 10 includes the first housing member 12 , the cover member 13 , and the second housing member 14 . In the present embodiment, the first housing member 12 rotatably supports the motor shaft 41 and the output shaft 61 from the upper side (one side in the axial direction). In addition, the second housing member 14 rotatably supports the motor shaft 41 and the output shaft 61 from the lower side (the other side in the axial direction).

The first housing member 12 accommodates the stator 43 inside. The first case member 12 has an opening 12a that opens upward and an opening 12b that opens downward. In this embodiment, the first housing member 12 is made of metal. The first housing part 12 is formed, for example, by die casting. The first housing member 12 has a polygonal shape when viewed in the vertical direction Z, for example.

The first housing member 12 has: a rectangular cylindrical outer wall portion 30 that constitutes a housing of the electric actuator 10; a bottom wall portion 31 that extends radially inward from a lower end portion of the outer wall portion 30; and a motor The case portion 32 and the output shaft upper holding portion 33 are provided on the bottom wall portion 31 . That is, the housing 11 has an outer wall portion 30 , a bottom wall portion 31 , a motor case portion 32 , and an output shaft upper holding portion 33 .

In the present embodiment, the outer wall portion 30 has a pentagon-shaped rectangular tube shape when viewed in the vertical direction Z. The outer wall portion 30 surrounds the motor case portion 32 from the radially outer side. The opening part on the upper side of the outer wall part 30 is the opening part 12a on the upper side of the first case member 12 . The bottom wall portion 31 has an opening portion that opens downward. The peripheral edge of the opening of the bottom wall portion 31 is provided with a cylindrical cylindrical wall 38 protruding downward from the bottom wall portion 31 . The cylindrical wall 38 has an annular shape surrounding the central axis J1 and the output axis J3. The opening surrounded by the cylindrical wall 38 is the opening 12b on the lower side of the first housing member 12. As shown in FIG.

The motor housing portion 32 and the output shaft upper holding portion 33 are provided on the upper surface of the bottom wall portion 31 . The motor case portion 32 has a cylindrical shape surrounding the motor portion 40 from the radially outer side. In the present embodiment, the motor case portion 32 has a cylindrical shape with the center axis J1 as the center and which is opened downward. The motor case portion 32 holds the motor portion 40 inside. More specifically, the stator 43 of the motor portion 40 is fixed to the inner peripheral surface of the motor case portion 32 . The motor housing portion 32 has a cylindrical portion 32b extending upward from the bottom wall portion 31, an annular plate-shaped partition wall 32a extending radially inward from an upper end portion of the cylindrical portion 32b, and Substrate fixing portion 32h.

The partition wall 32a has the 1st bearing holding part 32c which holds the 1st bearing 44a in the center as seen in the up-down direction Z. That is, the first housing member 12 has the first bearing holding portion 32c. The first bearing holding portion 32c has a cylindrical shape extending in the vertical direction Z with the center axis J1 as the center. The first bearing holding portion 32c is opened on the lower side. The first bearing 44a is held on the inner peripheral surface of the first bearing holding portion 32c. The first bearing 44a is fitted to the radially inner side of the first bearing holding portion 32c with a gap.

Since the partition wall 32a also functions as a bearing holder, the electric actuator 10 can be restrained from increasing in size in the vertical direction Z. The inner peripheral edge portion of the lower end portion of the first bearing holding portion 32c is chamfered. Thereby, the inner diameter of the lower end portion of the first bearing holding portion 32c increases toward the lower side.

The partition wall 32a has a guide hole 32f penetrating the partition wall 32a in the vertical direction Z. As shown in FIG. The guide hole 32f is provided in a portion of the partition wall 32a located radially inward of the inner peripheral surface 32e of the first bearing holding portion 32c. The guide hole 32f is, for example, a circular hole centered on the central axis J1. The lower end portion of the guide hole 32f is opened inside the first bearing holding portion 32c. Thereby, the inside of the guide hole 32f is connected to the inside of the first bearing holding portion 32c on the upper side of the first bearing holding portion 32c.

The board fixing portion 32h protrudes upward from the partition wall 32a. A plurality of substrate fixing portions 32h are provided. The substrate fixing portion 32h has a cylindrical shape. The board fixing portion 32h supports the circuit board 70 from the lower side. The upper end surface of the board fixing portion 32h is provided with a female screw hole. The bolts 96 penetrating the circuit board 70 in the vertical direction Z are screwed into the female screw holes of the board fixing portion 32h from the upper side. Thereby, the circuit board 70 is fixed to the board|substrate fixing|fixed part 32h.

The output shaft upper holding portion 33 has a cylindrical shape centered on the output axis J3. The output shaft upper holding portion 33 protrudes downward from the bottom wall portion 31 . A part of the side surface of the output shaft upper holding portion 33 is connected to the side surface of the motor case portion 32 . The output shaft upper holding portion 33 has a hole portion 33a penetrating the output shaft upper holding portion 33 in the vertical direction Z. A cylindrical sliding bearing 65 is fitted into the inner side of the hole portion 33a.

FIG. 2 is a perspective view of the electric actuator 10 .

The first housing part 12 has a fixing portion 34 . The fixing portion 34 has a female screw hole 36 on the lower end surface. That is, the first housing member 12 has a female screw hole (not shown) recessed upward. The first housing part 12 is provided with a plurality of fixing portions 34 . The plurality of fixing portions 34 are arranged at intervals along the circumference of the cylindrical wall 38 so as to surround the cylindrical wall 38 .

The first housing part 12 has a fastening surface 37 which faces downward. The fastening surface 37 is, for example, a flat surface perpendicular to the vertical direction Z. The fastening surface 37 is, for example, a machined surface. In addition, in this specification, "a certain surface is a machined surface" means that a certain surface is produced by performing machining such as cutting and grinding. In the present embodiment, the fastening surface 37 is a surface produced by cutting the surface of the first housing member 12 molded by die casting.

The outer edge of the fastening surface 37 of the first housing member 12 is provided with a first cutout portion (first positioning portion) 71 . That is, the first housing member 12 is provided with the first cutout portion 71 . The first cutout portion 71 has a cutout shape extending inward from the outer edge of the first housing member 12 when viewed in the axial direction. The first cutout portion 71 is used for positioning the first housing member 12 and the second housing member 14 in the circumferential direction around the center axis J1. The structure of the first notch portion 71 will be described in detail together with the description of the manufacturing method of the electric actuator 10 later.

As shown in FIG. 1 , the lid member 13 is a container-shaped member having a concave portion 13b opened downward. In this embodiment, the cover member 13 is made of metal. The cover member 13 is formed by die casting, for example. The cover member 13 is fixed to the upper side of the first case member 12 . More specifically, the cover member 13 and the first case member 12 are fastened to each other by a plurality of bolts penetrating the cover member 13 in the vertical direction Z. The cover member 13 closes the upper opening portion 12 a of the first housing member 12 . Although not shown, the concave portion 13 b accommodates electronic components mounted on the upper surface of the circuit board 70 . The concave portion 13b accommodates, for example, a capacitor, a transistor, and the like mounted on the circuit board 70 . The cover member 13 covers the output shaft 61 from the upper side.

The cover member 13 has an insertion hole 13 c located on the upper side of the output shaft 61 . When viewed in the vertical direction Z, the insertion hole 13 c overlaps with the operation portion 66 . A detachable plug member 15 is attached to the insertion hole 13c. For example, the plug member 15 is detachably attached to the insertion hole 13c by screwing the male screw portion provided on the outer peripheral surface into the female screw portion provided on the inner peripheral surface of the insertion hole 13c. Thereby, the insertion hole 13c is openably closed by the plug member 15 which is detachably attached. Therefore, it is possible to prevent foreign matter from entering the inside of the electric actuator 10 from the insertion hole 13c.

On the other hand, by removing the stopper member 15, a tool such as a polygonal column wrench can be inserted into the operation portion 66 from the outside of the electric actuator 10 through the insertion hole 13c. Thereby, the tool and the output shaft 61 can be connected. The output shaft 61 can be rotated by rotating the tool around the output axis J3 in a state where the tool is coupled to the output shaft 61 .

The second housing member 14 covers the speed reduction mechanism 50 from the lower side. In this embodiment, the second housing member 14 is made of metal. The second housing part 14 is formed, for example, by die casting. The second housing member 14 is fixed to the underside of the first housing member 12 . More specifically, as shown in FIG. 2 , the second case member 14 is fixed to the lower side of the first case member 12 by a plurality of bolts 97 . The bolts 97 are screwed into the female screw holes of the fixing portion 34 . In addition, the second case member 14 may be fastened to the first case member 12 by being fastened to a plate-shaped bracket.

As shown in FIG. 1 , the second casing member 14 closes the opening portion 12b on the lower side of the first casing member 12 . The second housing member 14 has a housing portion 14p and a flange portion 14c. The accommodating part 14p is a container-shaped part opened upward. The accommodating part 14p accommodates the speed reduction mechanism 50 inside. Thereby, the second housing member 14 accommodates the reduction mechanism 50 inside. The housing portion 14p includes a second bearing holding portion 14a, an inner bottom wall portion 14f, an inner peripheral wall portion 14b, an outer bottom wall portion 14j, an outer peripheral wall portion 14k, and a cylindrical portion 14r. That is, the second housing member 14 has a second bearing holding portion 14a, an inner bottom wall portion 14f, an inner peripheral wall portion 14b, an outer bottom wall portion 14j, an outer peripheral wall portion 14k, and a cylindrical portion 14r.

The second bearing holding portion 14a has a cylindrical shape centered on the central axis J1. The second bearing holding portion 14a is open to the upper side, and has a bottom portion 14d on the lower side. The inner diameter of the second bearing holding portion 14a is smaller than that of the inner peripheral wall portion 14b, and is positioned below the inner peripheral wall portion 14b. The second bearing holding portion 14a holds the second bearing 44b. The second bearing 44b is fitted to the radially inner side of the second bearing holding portion 14a. More specifically, the second bearing 44b is fitted to the radially inner side of the second bearing holding portion 14a with a gap. A preload member 47 is arranged between the second bearing 44b and the vertical direction Z of the bottom portion 14d. The preload member 47 is, for example, an annular wave washer extending in the circumferential direction. The preload member 47 is in contact with the upper surface of the bottom portion 14d and the lower end of the outer ring of the second bearing 44b. The preload member 47 applies an upward preload to the outer ring of the second bearing 44b.

The inner bottom wall portion 14f extends radially outward from the upper end portion of the second bearing holding portion 14a. The inner bottom wall portion 14f has an annular shape centered on the central axis J1. The inner peripheral wall portion 14b extends upward from the outer peripheral edge portion of the inner bottom wall portion 14f. The inner peripheral wall portion 14b is located radially outward of the second bearing holding portion 14a. The inner peripheral wall portion 14b has a cylindrical shape centered on the central axis J1. The inner peripheral wall portion 14b is opened to the upper side. An internally toothed gear 52 is fitted into the inside of the inner peripheral wall portion 14b. In the present embodiment, the internally toothed gear 52 is press-fitted into the inside of the inner peripheral wall portion 14b.

The outer bottom wall portion 14j expands radially outward from the upper end portion of the inner peripheral wall portion 14b. The outer shape viewed in the vertical direction Z of the outer bottom wall portion 14j is the same shape as the outer shape viewed in the vertical direction Z of the cylindrical wall 38 . The outer peripheral wall portion 14k extends upward from the outer peripheral edge portion of the outer bottom wall portion 14j. The outer peripheral wall portion 14k is positioned radially outward of the inner peripheral wall portion 14b. The outer shape of the outer peripheral wall portion 14k viewed in the up-down direction Z is the same shape as the outer shape of the cylindrical wall 38 viewed in the up-down direction Z. The outer peripheral wall portion 14k has an opening portion 14s that opens upward. The opening 14s of the second housing member 14 and the opening 12b on the lower side of the first housing member 12 face each other in the vertical direction Z. The output gear 53 is accommodated in the radially inner side of the outer peripheral wall portion 14k.

As shown in FIG. 2 , the cylindrical portion 14r protrudes downward from the outer bottom wall portion 14j. The cylindrical portion 14r has a cylindrical shape that is open to both sides in the vertical direction with the output axis J3 as the center. The inner surface of the cylindrical portion 14r is provided with an output shaft lower holding portion 14e that is opened downward. As shown in FIG. 1 , the output shaft lower holding portion 14e and the output portion 60 overlap in the vertical direction Z. As shown in FIG. The packing 61c is fitted into the outer peripheral surface of the lower end portion of the output shaft 61 . The output shaft lower holding portion 14e rotatably supports the output shaft 61 via the spacer 61c. The lower end portion of the output shaft 61 is exposed downward through the output shaft lower side holding portion 14e. The upper end portion of the cylindrical portion 14r supports the shaft flange portion 61b from the lower side.

The flange portion 14c extends radially outward from the upper end portion of the housing portion 14p. In the present embodiment, the flange portion 14c expands radially outward from the upper end portion of the outer peripheral wall portion 14k. The flange portion 14c has an annular shape surrounding the upper opening portion 14s of the housing portion 14p. In the present embodiment, the flange portion 14c surrounds the center axis J1 and the output axis J3.

As shown in FIG. 2, the flange part 14c has the through-hole 14i which penetrates the flange part 14c in the up-down direction Z. A plurality of through holes 14i are provided. For example, six through holes 14i are provided. The plurality of through holes 14i are arranged at intervals along the circumferential direction in which the flange portion 14c extends. The bolt 97 passes through the through hole 14i.

The flange portion 14c has a fastening surface 14m facing the upper side. The fastening surface 14m is a flat surface perpendicular to the vertical direction Z, for example. The fastening surface 14m is, for example, a machined surface. In the present embodiment, the fastening surface 14m is a surface produced by cutting the surface of the second housing member 14 molded by die casting.

The fastening surface 14 m of the second housing member 14 is in contact with the fastening surface 37 of the first housing member 12 . The fastening surface 14 m of the second housing member 14 is fixed to the fastening surface 37 of the first housing member 12 by means of bolts 97 .

The outer edge of the fastening surface 14m of the second housing member 14 is provided with a second cutout portion (second positioning portion) 72 . That is, the second housing member 14 is provided with the second cutout portion 72 . The second cutout portion 72 has a cutout shape extending inward from the outer edge of the second housing member 14 when viewed in the axial direction. The second cutout portion 72 is used for positioning the first housing member 12 and the second housing member 14 in the circumferential direction around the center axis J1. The first case member 12 and the second case member 14 are fixed in a state in which the first cutout portion 71 and the second cutout portion 72 overlap each other when viewed from the axial direction. The configuration of the second notch portion 72 will be described in detail together with the description of the manufacturing method of the electric actuator 10 later.

As shown in FIG. 1, the bus bar unit 90 is arranged on the upper surface of the partition wall 32a. The bus bar unit 90 includes an annular plate-shaped bus bar holder 91 and a plurality of bus bars 92 held by the bus bar holder 91 . For example, six bus bars 92 are provided. In the present embodiment, the bus bar holder 91 is produced by insert molding in which the bus bar 92 is an insert member. The bus bar holder 91 is fixed to the partition wall 32 a of the motor case portion 32 by, for example, a plurality of bolts 95 . Three bolts 95 are provided, for example.

One end portion 92 a of the bus bar 92 protrudes upward from the upper surface of the bus bar holder 91 . In the present embodiment, one end portion 92 a of the bus bar 92 penetrates through the circuit board 70 from the lower side to the upper side. The end portion 92a is electrically connected to the circuit board 70 by a connection method such as soldering, welding, press fitting, or the like at a position penetrating the circuit board 70 . Although not shown, the other end of the bus bar 92 holds the coil lead wire drawn from the coil 43c of the stator 43, and is connected to the coil 43c by welding or welding. Thereby, the stator 43 and the circuit board 70 are electrically connected via the bus bars 92 .

In the present embodiment, the circuit board 70 is arranged above the motor portion 40 and the bus bar unit 90 . The circuit board 70 has a plate shape whose board surface is perpendicular to the vertical direction Z. The motor part sensor 8 and the output part sensor 7 are mounted on the circuit board 70 . Although not shown in the drawings, the shape of the circuit board 70 as viewed in the vertical direction Z is a substantially square shape. The circuit board 70 is electrically connected to the coil 43 c of the stator 43 via the bus bar unit 90 . That is, the circuit board 70 and the motor unit 40 are electrically connected. In the present embodiment, the circuit board 70 is accommodated inside the opening portion 12 a of the first housing member 12 . The circuit board 70 is covered by the cover member 13 from the upper side. The circuit board 70 is fixed to the board fixing portion 32h of the motor case portion 32 by, for example, a plurality of bolts 96 .

The motor part sensor 8 is fixed to the lower surface of the circuit board 70 . More specifically, the motor unit sensor 8 is fixed to a portion of the lower surface of the circuit board 70 facing the first sensor magnet 45 in the vertical direction Z with a gap therebetween. The motor part sensor 8 is a magnetic sensor capable of detecting the magnetic field of the first sensor magnet 45 . The motor part sensor 8 is, for example, a Hall element such as a Hall IC. Although illustration is omitted, for example, three motor part sensors 8 are provided in the circumferential direction. The motor portion sensor 8 detects the rotation position of the first sensor magnet 45 by detecting the magnetic field of the first sensor magnet 45, thereby detecting the rotation of the motor shaft 41.

The output part sensor 7 is fixed to the lower surface of the circuit board 70 . More specifically, the output unit sensor 7 is fixed to a portion of the lower surface of the circuit board 70 facing the second sensor magnet 63 in the vertical direction Z with a gap therebetween. The output unit sensor 7 is a magnetic sensor capable of detecting the magnetic field of the second sensor magnet 63 . The output part sensor 7 is, for example, a Hall element such as a Hall IC. The output part sensor 7 detects the rotation position of the second sensor magnet 63 by detecting the magnetic field of the second sensor magnet 63 to detect the rotation of the output shaft 61 .

<Manufacturing method of electric actuator>

In this embodiment, the manufacturing method (assembly method) of the electric actuator 10 mainly includes a first preliminary step, a fixing step, a second preliminary step, and a cover member fixing step.

In the specification, the "worker, etc." includes a worker who performs each work, an assembling device, and the like. Each work may be performed only by the operator, only by the assembly device, or by both the operator and the assembly device. In addition, the 1st preparatory process and the fixing process of the electric actuator 10 of this embodiment are performed by the assembly apparatus which abbreviate|omits illustration.

The first preliminary step is a step of assembling the motor unit 40, the reduction mechanism 50, and the output unit 60 to the first housing member 12 and the second housing member 14. In the first preliminary step, the stator 43 is assembled to the first housing member 12 . On the other hand, the speed reduction mechanism 50 , the output portion 60 , and the rotor 40 a are assembled to the second housing member 14 .

Furthermore, in the first preliminary step, the first housing member 12 is attached to the assembling device so that the opening portion 12b faces downward. In the first preliminary step, the second case member 14 is attached to the assembling device so that the opening portion 14s faces upward. The opening 12b of the first housing member 12 and the opening 14s of the second housing member 14 are opposed to each other with a gap therebetween in the vertical direction.

The fixing step is a step of fixing the first casing member 12 and the second casing member 14 to each other. The fixing process includes a sealing process, a circumferential alignment process, and a fastening process. The closing step is a step of bringing the first casing member 12 and the second casing member 14 into contact with each other and closing the respective openings 12b and 14 of each other. The circumferential alignment step is a step of aligning the first housing member 12 and the second housing member 14 in the circumferential direction around the central axis J1. The tightening step is a step of fixing the first casing member 12 and the second casing member 14 to each other by tightening the bolts 97 .

In the closing step, the assembling device makes the first case member 12 and the second case member 14 approach each other in the up-down direction, and closes the openings 12b and 14s of each other. Thereby, the fastening surface 37 of the first housing member 12 and the fastening surface 14m of the second housing member 14 are brought into contact with each other.

The sealing process is performed using the above-mentioned assembly apparatus. The closing process is performed while the first housing member 12 and the second housing member 14 are aligned with respect to the central axis J1. In the closing step, the assembling device brings the first and second casing members 12 and 14 close to each other while securing the coaxiality between the guide hole 32f of the first casing member 12 and the rotor 40a assembled to the second casing member 14 . Thereby, the coaxiality of the 1st case member 12 and the 2nd case member 14 with respect to the center axis line J1 can be improved. This prevents the motor shaft 41 from being held twisted between the first housing member 12 and the second housing member 14, so that the rotational efficiency of the motor shaft 41 can be improved.

FIG. 3 is a plan view viewed from the lower side of the electric actuator 10 .

The circumferential alignment process is performed after the sealing process. In addition, the circumferential alignment process is performed while maintaining the coaxiality of the first housing member 12 and the second housing member 14 with respect to the central axis J1. By performing the closing step, the first notch portion 71 of the first housing member and the second notch portion 72 of the second housing member 14 overlap at least partially when viewed in the axial direction. However, the first case member 12 and the second case member 14 may be displaced in the circumferential direction with the center axis J1 as the center, so the first cutout portion 71 and the second cutout portion 72 do not completely overlap.

The circumferential alignment process is performed using the jig 9 . In the circumferential alignment process, an operator or the like inserts the jig 9 into the first cutout portion 71 and the second cutout portion 72 . The jig 9 is in contact with the opening edge of the first cutout portion 71 and the opening edge of the second cutout portion, respectively. Thereby, one or both of the first housing member 12 and the second housing member 14 are relatively rotated around the central axis J1, and the circumferential alignment is completed. After the circumferential alignment step, the fastening step is performed in a state in which the relative positional relationship between the first housing member 12 and the second housing member 14 is maintained.

According to the present embodiment, in the fixing process, the operator or the like makes the first cutout portion 71 and the second cutout portion 72 overlap each other when viewed from the axial direction, and inserts the jig 9 into the first cutout portion 71 and the second cutout portion 72 . The first case member 12 and the second case member 14 are fixed to each other in the state of the second cutout portion 72 . In addition, the fixing process is performed simultaneously with the alignment of the first housing member 12 and the second housing member 14 with respect to the central axis J1.

By performing the sealing process, the coaxiality on the central axis J1 of the first housing member 12 and the second housing member 14 is improved, but the coaxiality on the output axis J3 is not ensured. If the positional deviation of the first housing member 12 and the second housing member 14 on the output axis J3 occurs, the output shaft 61 is twisted, so that the rotational efficiency of the output shaft 61 may decrease.

According to the present embodiment, the fixing process is performed in a state where the operator or the like inserts the jig 9 into the first notch portion 71 and the second notch portion 72, whereby the first housing member 12 and the second housing member 14 can be attached to each other. Alignment process in the circumferential direction around the central axis J1. Therefore, alignment of the first housing member 12 and the second housing member 14 on the output axis J3 can be performed. That is, the coaxiality on the output axis J3 of the first housing member 12 and the second housing member 14 can be improved. As a result, it is possible to prevent the output shaft 61 from being held twisted between the first housing member 12 and the second housing member 14 , and it is possible to improve the rotational efficiency of the output shaft 61 .

Here, as shown in FIG. 3 , when the electric actuator 10 is viewed from the axial direction, an imaginary straight line VL passing through the central axis J1 and the first and second notch portions 71 and 72 is assumed.

The virtual straight line VL passes through the center of the first cutout portion 71 and the second cutout portion 72 when viewed from the axial direction. The output shaft 61 is arranged on the virtual straight line VL. In particular, in this embodiment, it is arrange|positioned on the output axis line J3 which passes through the center of the output shaft 61 on the virtual straight line VL. That is, the center axis J1 , the output axis J3 , and the first and second notches 71 and 72 are arranged on the imaginary straight line VL.

As shown in FIG. 1 , the first housing member 12 rotatably supports the motor shaft 41 via the first bearing 44a in the first bearing holding portion 32c. In addition, the first housing member 12 rotatably supports the output shaft 61 via the sliding bearing 65 in the output shaft upper holding portion 33 .

In order to ensure dimensional accuracy, the first bearing holding portion 32c, the output shaft upper holding portion 33, and the first notch portion 71 of the first housing member 12 are machined with an end mill or the like. Similarly, the second bearing holding portion 14a, the output shaft lower side holding portion 14e, and the second notch portion 72 of the second housing member 14 are machined.

According to the present embodiment, in the first housing member 12, the central axis J1, the output axis J3, and the first notch portion 71 are arranged on the virtual straight line VL. Therefore, during machining of the first bearing holding portion 32c, the output shaft upper holding portion 33, and the first notch portion 71, by making the moving direction of the main shaft of the machine tool coincide with the direction of the imaginary straight line VL, they can be processed. Machining without moving the spindle in a direction perpendicular to the imaginary line VL. As a result, the dimensional accuracy of the first bearing holding portion 32c, the output shaft upper holding portion 33, and the first notch portion 71 with respect to the virtual straight line VL can be improved. Thereby, the dimensional accuracy of the output axis J3 in the circumferential direction of the central axis J1 and the first notch portion 71 can be improved by machining the first housing member 12 .

Similarly, the second housing member 14 rotatably supports the motor shaft 41 in the second bearing holding portion 14a via the second bearing 44b. In addition, the second housing member 14 rotatably supports the output shaft 61 via the spacer 61c in the output shaft lower side holding portion 14e. According to the present embodiment, when the second bearing holding portion 14a, the output shaft lower holding portion 14e, and the second notch portion 72 are machined, by making the moving direction of the main shaft of the machine tool coincide with the direction of the imaginary straight line VL, it is possible to They are machined without moving the spindle in a direction perpendicular to the imaginary line VL. As a result, the dimensional accuracy of the second bearing holding portion 14a, the output shaft lower side holding portion 14e, and the second notch portion 72 with respect to the virtual straight line VL can be improved. Thereby, the dimensional accuracy of the output axis J3 in the circumferential direction of the central axis J1 and the first notch portion 71 can be improved by machining the second housing member 14 .

In this way, according to the present embodiment, in the circumferential direction of the central axis J1, the positional accuracy of the portions of the first housing member 12 and the second housing member 14 holding the output shaft 61 and the first and second cutout portions 71 and 72 are improved. . Accordingly, by aligning the first notch portion 71 and the second notch portion 72 in the circumferential direction of the central axis J1, the holding capacity of the output shaft 61 of the first housing member 12 and the second housing member 14 can be improved more reliably. The positional accuracy of the parts (the output shaft upper holding portion 33 and the output shaft lower holding portion 14e).

As shown in FIG. 3 , the first notch portion 71 and the second notch portion 72 have the same shape when viewed from the axial direction. In addition, each of the first cutout portion 71 and the second cutout portion 72 has a mirror-symmetrical shape with respect to the virtual straight line VL. As described above, the first notch portion 71 and the second notch portion 72 of the present embodiment are formed by machining, respectively. By making the first notch portion 71 and the second notch portion 72 mirror-symmetrical with respect to the virtual straight line VL, the dimensional accuracy on both sides in the circumferential direction with respect to the central axis J1 can be precisely processed to the same degree. As a result, the dimensional accuracy of the first notch portion 71 and the second notch portion 72 on both sides in the circumferential direction with respect to the central axis J1 can be improved.

The first cutout portion 71 and the second cutout portion 72 of the present embodiment have the same width portion 73 and the circular arc portion 74 . The same-width portion 73 is a region extending from the opening of the first notch portion 71 or the second notch portion 72 with the same width along the imaginary straight line VL, and has a pair of wall surfaces facing each other in the width direction. The circular arc portion 74 is arranged at the bottom of the first cutout portion 71 or the second cutout portion 72 in the depth direction. The circular arc portion 74 has a semicircular arc shape when viewed from the axial direction, and connects the pair of wall surfaces of the same width portion 73 to each other. The diameter of the circular arc portion 74 is the same as the width dimension of the same width portion 73 . The first notch portion 71 and the second notch portion 72 are machined using end mills having the same diameter as the width dimension of the same width portion 73 . That is, according to the present embodiment, the first notch portion 71 and the second notch portion 72 can be formed by moving the main shaft of the machine tool along the virtual straight line VL during machining of the first notch portion 71 and the second notch portion 72 . . Therefore, the dimensional accuracy of the first notch portion 71 and the second notch portion 72 in the circumferential direction of the central axis J1 can be improved.

In addition, in the present embodiment, a case where a notch-shaped positioning portion (the first notch portion 71 and the second notch portion 72 ) is provided as the positioning portion of the first housing member 12 and the second notch portion 72 will be described. . However, the positioning portion is not limited to the present embodiment as long as the positioning portions are provided on the first housing member 12 and the second housing member 14, respectively, and open to both sides in the axial direction. For example, a through hole penetrating in the axial direction may be used instead of the notched positioning portion.

In addition, as shown in the present embodiment, by using the first notch portion 71 and the second notch portion 72 as notch-shaped positioning portions, the jig 9 can be inserted from the notch opening side along the virtual straight line VL. Therefore, according to this embodiment, the positioning of the first housing member 12 and the second housing member 14 can be performed easily and with high accuracy.

When viewed from the axial direction, the jig 9 has a wedge shape whose width becomes narrower toward the front end side along the imaginary straight line VL. The width dimension of the front end of the jig 9 is smaller than the width dimension of the same width portion 73 of the first cutout portion 71 and the second cutout portion 72 . The width dimension of the root portion of the jig 9 is larger than the width dimension of the same width portion 73 of the first cutout portion 71 and the second cutout portion 72. In the fixing process, the jig 9 is inserted into the first cutout portion 71 and the second cutout portion 72 along the imaginary line VL, and contacts the opening edges of the first cutout portion 71 and the second cutout portion 72 .

According to the present embodiment, by making the jig 9 into a wedge shape, by inserting the jig along the imaginary straight line VL, the first housing member 12 and the second housing member 14 can be easily aligned.

As described above, the circumferential positional accuracy of the first notch portion 71 and the second notch portion 72 of the first housing member 12 and the second housing member 14 of the present embodiment is improved. On the other hand, the first notch portion 71 and the second notch portion 72 are processed by moving a cutting tool such as an end mill along the imaginary line VL. Therefore, the dimensional accuracy in the depth direction of the first cutout portion 71 and the second cutout portion 72 is not improved. According to the present embodiment, the jig 9 is in contact with the opening edges of the first cutout portion 71 and the second cutout portion 72. Therefore, regardless of the dimensional accuracy of the first notch portion 71 and the second notch portion 72 in the depth direction, the first notch portion 71 and the second notch portion 72 can be positioned with high precision.

FIG. 4 is a perspective view of the first cutout portion 71 and the second cutout portion 72 and the jig 9 inserted into them. As shown in FIG. 4 , the jig 9 preferably has a first jig piece 9a and a second jig piece 9b which are separated from each other.

The first jig piece 9a and the second jig piece 9b have the same shape. That is, the first jig piece 9a and the second jig piece 9b are wedge shapes whose widths become narrower as they go toward the front end sides along the imaginary straight line VL. The first jig piece 9a and the second jig piece 9b extend in the axial direction with the same cross-sectional shape. The first jig piece 9a and the second jig piece 9b are stacked in the axial direction.

The first jig piece 9a and the second jig piece 9b are connected to each other. The first jig piece 9a and the second jig piece 9b are allowed to move relatively in the direction along the imaginary straight line VL. On the other hand, the first jig piece 9a and the second jig piece 9b are not allowed to move relatively in directions other than the direction along the imaginary straight line VL. That is, the first jig piece 9a and the second jig piece 9b restrict relative movement in the direction perpendicular to the virtual straight line VL.

The first jig piece 9 a is arranged to face the first cutout portion 71 . On the other hand, the second jig piece 9b is arranged to face the second cutout portion 72 . The boundary surface between the first jig piece 9a and the second jig piece 9b and the boundary surface between the first housing member 12 and the second housing member 14 are arranged on the same plane. The first jig piece 9 a is inserted into the first cutout portion 71 along the imaginary straight line VL, and is in contact with the opening edge of the first cutout portion 71 . The second jig piece 9b is inserted into the second cutout portion 72 along the imaginary straight line VL, and is in contact with the opening edge of the second cutout portion 72 .

In the present embodiment, the position of the opening edge of the first notch portion 71 and the position of the opening edge of the second notch portion 72 may be shifted in the direction along the virtual straight line VL. This is because the shape of the outer edge of the first housing member 12 provided with the first cutout portion 71 and the shape of the outer edge of the second housing member 14 provided with the second cutout portion 72 do not necessarily coincide.

According to the present embodiment, the first jig piece 9a and the second jig piece 9b can each independently move along the virtual straight line VL. Therefore, even if the positions of the opening edges of the first notch portion 71 and the second notch portion 72 are arranged to be offset from each other in the direction along the virtual straight line VL, the jig 9 can accurately perform circumferential positioning.

After the fixing step, a second preliminary step and a cover member fixing step are performed. The second preliminary step is a step of attaching the circuit board 70 and the bus bar unit 90 to the second housing member 14 . In addition, the cover member fixing step is a step of fixing the cover member 13 to the second case member 14 . By going through the cover member fixing process, the electric actuator 10 is manufactured.

The embodiments of the present invention have been described above, but each configuration of each embodiment and these combinations are given as examples, and additions, omissions, substitutions, and other modifications of configurations are possible without departing from the gist of the present invention. . In addition, this invention is not limited to embodiment.

The electric actuator to which the present invention is applied may be a device that can move a target object by being supplied with electric power, and may be a motor without a speed reduction mechanism. In addition, the electric actuator may be an electric pump including a pump portion driven by a motor portion. The use of the electric actuator is not particularly limited. The electric actuator may be mounted on a shift-by-wire actuator device that is driven in accordance with a driver's shift operation. In addition, the electric actuator may be mounted on equipment other than the vehicle. Moreover, each structure demonstrated in this specification can be combined suitably in the range which does not contradict each other.

Claims (3)

1. An electric actuator, characterized in that, The electric actuator has: a motor portion having a motor shaft that rotates around a central axis; a transmission mechanism connected to the motor shaft; an output shaft that rotates around an output axis parallel to the central axis, to which the power of the motor shaft is transmitted via the transmission mechanism; a first housing member rotatably supporting the motor shaft and the output shaft from one axial side; and a second housing member that rotatably supports the motor shaft and the output shaft from the other side in the axial direction, A first positioning portion is provided on the first housing member, The second housing member is provided with a second positioning portion, The first housing member and the second housing member are fixed in a state in which the first positioning portion and the second positioning portion overlap each other when viewed from the axial direction, The output shaft is disposed on an imaginary straight line passing through the central axis, the first positioning portion, and the second positioning portion when viewed from the axial direction. 2. The electric actuator of claim 1, wherein: The first positioning portion and the second positioning portion are respectively mirror-symmetrical with respect to the imaginary straight line. 3. The electric actuator of claim 2, wherein The first positioning portion is in the shape of a notch extending inward from the outer edge of the first housing member when viewed from the axial direction, The second positioning portion has a notch shape extending inward from the outer edge of the second housing member when viewed in the axial direction.

Images