Motor device and actuator

Abstract

A motor device (2) is provided with: an output shaft (34); a motor housing (33) having an insertion hole (51) through which the output shaft (34) is inserted, and a through-hole (52); and a filter member (53) mounted to the through-hole (52). The outer surface of the motor housing (33) includes an attachment surface (46) in which the insertion hole (51) is formed and to which a transmission housing (11) is attached, and an outer peripheral surface (47) that extends in the axial direction from the outer peripheral edge of the attachment surface (46). The attachment surface (46) is provided with a mounting groove (56) for mounting an annular seal member (57) surrounding the insertion hole (51). Of the outer surface of the motor housing (33), a region surrounded by the mounting groove (56) is an inner region, and a region outside the mounting groove (56) is an outer region. The through-hole (52) is formed in the outer region.

Description

Motor device and actuator

[0001] The present disclosure relates to a motor device and an actuator.

[0002] Conventionally, there has been an actuator including a motor device and a transmission device that transmits rotation output from the motor device. For example, Patent Document 1 discloses an actuator used as a source of assist force that assists a driver's steering operation in a vehicle steering device.

[0003] The motor device provided in the actuator described in Patent Document 1 includes a motor housing with a through-hole and a filter member attached to the through-hole. The filter member is waterproof and breathable. Therefore, when the temperature inside the motor housing rises due to heat generated by the passage of current through the motor device, air is released from the motor housing through the filter member. This improves the heat dissipation performance of the motor device described in Patent Document 1 and reduces the occurrence of failures due to overheating.

[0004] Japanese Patent Application Laid-Open No. 2007-124798

[0005] In recent years, there has been a demand for further improvement in reliability in motor devices and actuators equipped with the same. Therefore, even if the occurrence of failures is suppressed by adopting the configuration described in Patent Document 1, it cannot be said that the required level has been reached.

[0006] According to one aspect of the present disclosure, there is provided a motor device coupled to a transmission device. The transmission device includes a transmission housing, a transmission member accommodated in the transmission housing, and lubricating oil filled within the transmission housing. The motor device includes an output shaft coupled to the transmission member, a motor housing rotatably accommodating the output shaft, the motor housing having an insertion hole through which the output shaft is inserted and a through hole communicating between the inside and outside of the motor housing, and a filter member attached to the through hole. The outer surface of the motor housing includes a mounting surface into which the insertion hole opens and to which the transmission housing is attached, and an outer peripheral surface extending axially from the outer peripheral edge of the mounting surface. The mounting surface is provided with a mounting groove for mounting an annular seal member surrounding the insertion hole. The area of ​​the outer surface of the motor housing surrounded by the mounting groove is an inner region, and the area outside the mounting groove is an outer region. The through hole opens into the outer region.

[0007] According to another aspect of the present disclosure, there is provided an actuator including a motor device and a transmission device configured to transmit rotation of the motor device. The transmission device includes a transmission housing, a transmission member accommodated in the transmission housing, and lubricating oil filled within the transmission housing. The motor device includes an output shaft connected to the transmission member, a motor housing rotatably accommodating the output shaft, the motor housing having an insertion hole through which the output shaft is inserted and a through hole communicating between the inside and outside of the motor housing, and a filter member attached to the through hole. The outer surface of the motor housing includes a mounting surface into which the insertion hole opens and to which the transmission housing is attached, and an outer peripheral surface extending in the axial direction from the outer peripheral edge of the mounting surface. An annular seal member surrounding the insertion hole is provided between the transmission housing and the motor housing. The area of ​​the outer surface of the motor housing surrounded by the seal member is an inner region, and the area outside the seal member is an outer region. The through hole opens into the outer region.

[0008] Fig. 2 is a perspective view of an actuator equipped with a motor device according to an embodiment; Fig. 3 is a cross-sectional view of the motor device and its vicinity in the actuator of Fig. 1; Fig. 4 is a bottom view of the motor device of Fig. 1; Fig. 5 is an enlarged cross-sectional view of the vicinity of a filter member in the motor device of Fig. 1; Fig. 6 is a schematic view of an air leak test being performed on the motor device of Fig. 1;

[0009] An embodiment of a motor device and an actuator including the same will be described below with reference to the drawings. Note that the term "cylindrical" in this specification includes, but is not limited to, circular, elliptical, and polygonal with sharp or rounded corners. Also, the term "annular" or "ring-shaped" in this specification includes, but is not limited to, circular, elliptical, and polygonal with sharp or rounded corners.

[0010] 1 includes a motor device 2 and a transmission device 3 that transmits rotation output from the motor device 2. The actuator 1 of this embodiment is used in a vehicle steering device as a source of an assist force that assists a driver's steering operation or a steering force that steers steered wheels.

[0011] (Transmission Device) The transmission device 3 includes a transmission housing 11 and a transmission mechanism (not shown) housed within the transmission housing 11. The transmission mechanism includes, for example, a gear mechanism, a ball screw mechanism, and a sector gear. The gear mechanism reduces the speed of the rotation output from the motor device 2 and transmits it to the ball screw mechanism. The ball screw mechanism converts the rotation transmitted from the gear mechanism into linear motion of a ball screw nut and transmits it to the sector gear. The sector gear rotates in accordance with the linear motion of the ball screw nut and transmits the rotation to the steering mechanism. This changes the steering angle of the steered wheels.

[0012] The transmission housing 11 includes a first housing member 12, a second housing member 13, and a third housing member 14. A gear mechanism is housed in the first housing member 12 and the second housing member 13. A ball screw mechanism and a sector gear are housed in the third housing member 14.

[0013] 1 and 2, the first housing member 12 has a flat, cylindrical shape with one end closed. The first housing member 12 is provided with a flange portion 15 that extends radially outward from the open end of the first housing member 12.

[0014] The second housing member 13 is generally cylindrical. A flat plate portion 16 is provided on the second housing member 13. The plate portion 16 extends radially outward from one end of the second housing member 13. The second housing member 13 is disposed on the first housing member 12 so as to cover the opening of the first housing member 12. The first housing member 12 and the second housing member 13 are connected to each other by bolts (not shown). As shown in FIG. 2 , the plate portion 16 has an intermediate hole 17 that penetrates through the plate portion 16 in the thickness direction. A seal member 18, such as an O-ring, is provided between the first housing member 12 and the second housing member 13.

[0015] 1, the third housing member 14 is generally cylindrical. The third housing member 14 is disposed on the second housing member 13 with a portion of the third housing member 14 inserted into the second housing member 13. The second housing member 13 and the third housing member 14 are connected to each other by bolts (not shown).

[0016] The motor device 2 is disposed on the first housing member 12 via the plate portion 16. As shown in Figure 2, the motor device 2 is connected to the first housing member 12 and the second housing member 13 by bolts 19 inserted through the flange portion 15 of the first housing member 12 and the plate portion 16 of the second housing member 13.

[0017] The first housing member 12 accommodates a first gear 21, which serves as a transmission member, and a second gear 22, which meshes with the first gear 21. In FIG. 2 , the second gear 22 meshes with the first gear 21 on the far side of the page. The gear mechanism is made up of multiple gears, including the first gear 21 and the second gear 22. The first gear 21 and the second gear 22 are rotatably accommodated within the first housing member 12. In this embodiment, the first gear 21 and the second gear 22 are spur gears with helical teeth. The number of teeth of the first gear 21 is smaller than the number of teeth of the second gear 22. The first housing member 12 is filled with lubricating oil 23, which ensures smooth operation of the gear mechanism. For ease of explanation, the lubricating oil 23 is indicated by dotted hatching in FIG. 2 .

[0018] As will be described later, the first gear 21 is connected to an output shaft 34 of the motor device 2 so as to be rotatable together with the first gear 21. The second gear 22 is connected to a screw shaft of the ball screw mechanism via one or more gears (not shown). As a result, the rotation output from the motor device 2 is decelerated by the gear mechanism and transmitted to the ball screw mechanism as described above.

[0019] (Motor Device) As shown in FIGS. 1 and 2, the motor device 2 includes a motor 31 and a controller 32 that controls the operation of the motor 31.

[0020] First, a description will be given of the structure of the motor 31. As shown in Fig. 2, the motor 31 includes a motor housing 33, an output shaft 34, a stator 35, and a rotor 36.

[0021] The motor housing 33 includes a housing body 41 and a bearing holder 42. The housing body 41 is generally cylindrical with one end closed. Hereinafter, the direction along the axis of the housing body 41 will be referred to as the axial direction.

[0022] Specifically, the housing main body 41 has a cylindrical peripheral wall portion 43 and an end wall portion 44 that closes one end of the peripheral wall portion 43. In this embodiment, the peripheral wall portion 43 has a circular shape when viewed in the axial direction. A flange portion 45 (see FIG. 1 ) that protrudes radially outward is provided at the closed end of the peripheral wall portion 43. The bolts 19 that are inserted through the flange portion 15 of the first housing member 12 and the plate portion 16 of the second housing member 13 are threadedly fastened to the flange portion 45. As a result, the housing main body 41 is connected to the transmission housing 11 with the end wall portion 44 abutting against the plate portion 16. In other words, the outer end surface of the end wall portion 44 corresponds to a mounting surface 46 to which the transmission device 3 is attached.

[0023] The end wall portion 44 has a first insertion hole 51. The first insertion hole 51 penetrates the end wall portion 44 in the axial direction and connects the inside and outside of the motor housing 33. The first insertion hole 51 is located at the center of the end wall portion 44. The end wall portion 44 also has a through hole 52 in addition to the first insertion hole 51. The through hole 52 penetrates the end wall portion 44 in the axial direction and connects the inside and outside of the motor housing 33. A breathable and waterproof filter member 53 is attached to the through hole 52. This allows air to flow in and out of the motor housing 33 via the through hole 52. The through hole 52 and the filter member 53 will be described in detail below.

[0024] A cylindrical first retaining portion 54 is provided on the inner end surface of the end wall portion 44, protruding from the periphery of the first insertion hole 51 into the peripheral wall portion 43. In this embodiment, the first retaining portion 54 has a circular shape when viewed in the axial direction. A first bearing 55 is attached to the first retaining portion 54.

[0025] As shown in FIGS. 2 and 3 , the mounting surface 46 of the end wall portion 44 has an annular mounting groove 56 surrounding the first insertion hole 51. In this embodiment, the mounting groove 56 has a circular shape when viewed in the axial direction. That is, the mounting groove 56 has an endless loop shape. An annular seal member 57 is mounted in the mounting groove 56. In this embodiment, the seal member 57 is, for example, an O-ring and has a circular shape when viewed in the axial direction. That is, the seal member 57 has an endless loop shape. The seal member 57 is compressed in the axial direction between the end wall portion 44 and the plate portion 16 of the second housing member 13. This seals the gap between the motor housing 33 and the transmission housing 11. Therefore, the lubricating oil 23 filled in the transmission housing 11 does not leak outside the area surrounded by the seal member 57 between the motor housing 33 and the transmission housing 11.

[0026] The housing main body 41 further has an extension portion 61 extending radially outward from the open end of the peripheral wall portion 43, and a frame portion 62 extending axially from the outer peripheral edge of the extension portion 61. The extension portion 61 has a rectangular shape when viewed in the axial direction. The extension portion 61 significantly protrudes in one longitudinal direction from the peripheral wall portion 43. The extension portion 61 has a window portion 63 penetrating in the axial direction. The window portion 63 is, for example, a rectangular hole.

[0027] The frame portion 62 extends from the outer peripheral edge of the extension portion 61 along the axial direction, away from the end wall portion 44. The frame portion 62 extends around the entire circumference of the extension portion 61. In other words, the frame portion 62 has a rectangular shape corresponding to the extension portion 61 when viewed in the axial direction. The frame portion 62 forms the open end of the housing main body 41.

[0028] As shown in FIG. 2 , the bearing holder 42 has a flat plate shape. The bearing holder 42 is fixed to the housing main body 41 so as to cover the open end of the peripheral wall portion 43. The bearing holder 42 has a second insertion hole 71. The second insertion hole 71 penetrates the bearing holder 42 in the axial direction and communicates between the inside and outside of the motor housing 33. The second insertion hole 71 is located at the center of the bearing holder 42. A cylindrical second retaining portion 72 is provided on the inner surface of the bearing holder 42 facing the inside of the housing main body 41, protruding from the periphery of the second insertion hole 71 into the housing main body 41. In this embodiment, the second retaining portion 72 has a circular shape when viewed in the axial direction. A second bearing 73 is attached to the second retaining portion 72.

[0029] The output shaft 34 has a first end 81 and a second end 82. The first end 81 of the output shaft 34 is rotatably supported by the first bearing 55, and the second end 82 of the output shaft 34 is rotatably supported by the second bearing 73. As a result, the output shaft 34 is rotatably accommodated within the motor housing 33. The axis of the output shaft 34 coincides with the axis of the peripheral wall portion 43.

[0030] The tip of the first end 81 protrudes outside the motor housing 33 through the first insertion hole 51. In this embodiment, the tip of the first end 81 is disposed in an intermediate hole 17 provided in the plate portion 16 of the second housing member 13. That is, the tip of the first end 81 protrudes into the transmission housing 11. The tip of the first end 81 is coupled to the first gear 21 so as to be rotatable integrally therewith. A lip seal 83 is provided between the tip of the first end 81 and the first insertion hole 51. This prevents the lubricating oil 23 from entering the motor housing 33.

[0031] The stator 35 includes a stator core 91 and coils 92 wound around the teeth of the stator core 91. The stator core 91 is fixed to the inner circumferential surface of the peripheral wall portion 43. The coils 92 are connected to the controller 32 via bus bars 93.

[0032] The rotor 36 includes a cylindrical rotor core 94 fixed to rotate integrally with the output shaft 34, and a plurality of permanent magnets 95 fixed to the rotor core 94. In the illustrated example, the permanent magnets 95 are fixed to the outer peripheral surface of the rotor core 94, but this is not limiting and the permanent magnets 95 may be embedded in the rotor core 94. When a rotating magnetic field is generated by supplying electric power to the stator 35 from a power source (not shown), the rotor 36 rotates integrally with the output shaft 34.

[0033] Next, the configuration of the controller 32 will be described. As shown in Figures 2 and 3, the controller 32 includes a circuit board 101, a connector 102, and a cover 103. The circuit board 101 is fixed to the housing main body 41 so as to be located above the bearing holder 42. Various circuit elements are mounted on the circuit board 101. As a result, the circuit board 101 is configured with a power circuit for supplying power to the motor 31, a control circuit for controlling the power circuit, and the like.

[0034] As shown in FIG. 3 , the connector 102 is a rectangular plate that is larger than the window 63 of the housing main body 41. The connector 102 has a connection port 104 for connecting a cable (not shown). The connector 102 does not have a hole that penetrates the connector 102, and is configured to prevent air from passing through the connector 102. The connector 102 is fixed to the extension portion 61 so that the connection port 104 protrudes from the window 63. A sealing member 105, such as an O-ring or adhesive, is provided around the entire periphery of the window 63 between the inner peripheral edge of the window 63 and the connector 102. This provides a seal between the window 63 and the connector 102.

[0035] As shown in Fig. 2, the cover 103 has a rectangular box shape with one side open. When viewed in the axial direction, the cover 103 has a rectangular shape corresponding to the extension portion 61. The cover 103 does not have any holes penetrating the cover 103, and is configured to prevent air from passing through the cover 103. The cover 103 is fixed to the frame portion 62 so as to close the open end of the housing main body 41. A sealing member 106 such as an adhesive is provided around the entire periphery of the frame portion 62 between the open end of the cover 103 and the tip of the frame portion 62. This seals the gap between the housing main body 41 and the cover 103.

[0036] In the motor device 2 configured in this manner, the first insertion holes 51 and the through holes 52 provided in the end wall portion 44 are blocked, thereby preventing gas such as air from entering or leaving the motor device 2. In other words, the motor device 2 is configured so that the interior of the motor device 2 is sealed except for the first insertion holes 51 and the through holes 52.

[0037] Therefore, if the temperature inside the motor housing 33 rises due to, for example, heat generation caused by energizing the coil 92 or an increase in the ambient temperature, air is released from the motor housing 33 through the filter member 53. This prevents the pressure inside the motor housing 33 from becoming excessive, and prevents damage to, for example, the cover 103, etc.

[0038] On the other hand, if the lubricating oil 23 adheres to the filter member 53, its breathability decreases. As a result, if the temperature inside the motor housing 33 changes, air is prevented from passing through the filter member 53 to the motor housing 33. In consideration of this, in the motor device 2 of this embodiment, the position of the through hole 52 to which the filter member 53 is attached is set so that the lubricating oil 23 does not adhere to the filter member 53.

[0039] Here, the outer surface of the motor housing 33 includes the mounting surface 46 of the end wall portion 44, the outer peripheral surface 47 of the peripheral wall portion 43, the outer surface 48 of the extension portion 61, and the outer peripheral surface 49 of the frame portion 62. The outer peripheral surface 47 of the peripheral wall portion 43 is a cylindrical surface extending in the axial direction from the outer peripheral edge of the mounting surface 46. The outer surface 48 of the extension portion 61 is a flat surface extending radially outward from the end of the outer peripheral surface 47 of the peripheral wall portion 43 opposite the mounting surface 46. The outer peripheral surface 49 of the frame portion 62 is a cylindrical surface extending in the axial direction from the outer peripheral edge of the outer surface 48 of the extension portion 61. Of the outer surface of the motor housing 33, the area surrounded by the mounting groove 56 on the mounting surface 46, i.e., the area surrounded by the seal member 57, is defined as the inner region, and the area outside the mounting groove 56, i.e., the area outside the seal member 57, is defined as the outer region. As described above, the seal member 57 prevents leakage of the lubricating oil 23 , so the inner region is a region that comes into contact with the lubricating oil 23 , and the outer region is a region that does not come into contact with the lubricating oil 23 .

[0040] As shown in Figures 2 to 4, the through hole 52 in this embodiment opens to an outer region of the outer surface of the motor housing 33. More specifically, the through hole 52 opens to an outer region within the mounting surface 46. The through hole 52 is also positioned slightly inward from the outer peripheral edge of the mounting surface 46. In other words, the through hole 52 is positioned so as not to open to the outer peripheral surface 47 of the peripheral wall portion 43. As a result, the outer peripheral edge of the mounting surface 46 is flat and smooth all around. The through hole 52 also opens to a portion of the mounting surface 46 that is not covered by the transmission housing 11. In other words, the through hole 52 is exposed to the outside of the transmission housing 11. Note that in Figure 3, the outer shape of the transmission housing 11 is indicated by a two-dot chain line. The through hole 52 in this embodiment is a stepped circular hole. Specifically, the through hole 52 has a large diameter hole portion 111 that opens to the mounting surface 46 of the end wall portion 44 , and a small diameter hole portion 112 that opens to the bottom surface of the large diameter hole portion 111 and the inner bottom surface of the end wall portion 44 .

[0041] As shown in FIG. 4 , the filter member 53 includes a base 121, a porous membrane 122, a cap 123, and a sealing member 124. The base 121 and the cap 123 are made of, for example, a resin material. The base 121 is annular. In this embodiment, the base 121 has a circular shape when viewed in the axial direction. The base 121 has multiple locking claws 125 protruding axially from its inner periphery. The multiple locking claws 125 are arranged at equal angular intervals around the inner periphery of the base 121. A sealing member 124, such as an O-ring, is attached to the outer periphery of the multiple locking claws 125. The porous membrane 122 is a thin sheet. The porous membrane 122 is made of a porous material, such as polytetrafluoroethylene (PTFE), and is configured to allow gases such as air to pass through while restricting the passage of liquids such as water. The porous membrane 122 is attached to the base 121 so as to cover the opening of the base 121. The cap 123 has a disk shape and is fixed to the base 121 with a gap between the cap 123 and the porous membrane 122. An opening extending in the circumferential direction is formed between the base 121 and the cap 123.

[0042] The filter member 53 is attached to the through hole 52 by inserting the locking claws 125 into the small diameter hole portion 112 and locking them against the inner end surface of the end wall portion 44. A seal member 124 seals the gap between the base 121 and the locking claws 125 and the inner circumferential surface of the small diameter hole portion 112. The outer diameters of the base 121 and the cap 123 are smaller than the inner diameter of the large diameter hole portion 111. The height from the step surface between the large diameter hole portion 111 and the small diameter hole portion 112 to the surface of the cap 123 is less than the depth of the large diameter hole portion 111. Therefore, the filter member 53 is housed in the through hole 52 so as not to protrude from the outer end surface of the end wall portion 44.

[0043] Therefore, for example, if the temperature inside the motor housing 33 rises, the air passes through the porous membrane 122 and is released to the outside of the motor device 2 through the gap between the base 121 and the cap 123. On the other hand, if the temperature inside the motor housing 33 drops, for example, the air moves in the opposite direction to when the temperature rises, and is drawn into the motor housing 33.

[0044] (Air Leak Test) Next, an air leak test for the motor device 2 will be described. As described above, the motor device 2 is sealed to prevent air from entering or leaving the motor device 2, except for the first insertion hole 51 and the through-hole 52. The air leak test is performed to check whether the motor device 2 has appropriate sealing performance. The air leak test is performed after the motor device 2 has been assembled and before it is attached to the transmission device 3.

[0045] As shown in FIG. 5, the air leak test is performed based on whether or not air leaks from the motor device 2 when air is blown into the motor device 2 while a jig 131 is pressed against the mounting surface 46 of the motor housing 33.

[0046] Specifically, the jig 131 has a cylindrical portion 132. In this embodiment, the cylindrical portion 132 has a circular shape when viewed in the axial direction. The cylindrical portion 132 has an outer diameter approximately equal to the outer diameter of the mounting surface 46. A seal member 133 is provided at the tip of the cylindrical portion 132 around the entire circumference of the cylindrical portion 132. The seal member 133 is made of, for example, a rubber material and has a rectangular cross-section. When performing an air leak test, the seal member 133 is pressed against the mounting surface 46 of the motor housing 33 to seal between the jig 131 and the motor housing 33. Then, air is pumped from an air supply source connected to the jig 131 into the motor housing 33 of the motor device 2 being tested, as indicated by the white arrow in FIG. 5 . If no air leaks from the motor device 2, it is determined that the motor device 2 has appropriate sealing performance. On the other hand, if air leaks from the motor device 2, it is determined that the motor device 2 does not have appropriate sealing performance.

[0047] Next, the operation and effects of this embodiment will be described. (1) The through-hole 52 opens to an outer region of the outer surface of the motor housing 33, which is outside the inner region surrounded by the seal member 133. With this configuration, the lubricating oil 23 filled in the transmission housing 11 does not come into contact with the filter member 53. This prevents the lubricating oil 23 from adhering to the filter member 53, thereby preventing a decrease in its breathability. As a result, even if the temperature inside the motor housing 33 changes, air is not prevented from entering or exiting the motor housing 33 via the filter member 53. Therefore, while the lubricating oil 23 ensures smooth operation of the transmission device 3, a decrease in the breathability of the filter member 53 is suppressed, improving the reliability of the motor device 2.

[0048] (2) The through-hole 52 opens to an outer region within the mounting surface 46. With this configuration, the through-hole 52 opens in the same direction as the first insertion hole 51. Therefore, for example, the through-hole 52 can be easily covered together with the first insertion hole 51 by the jig 131 used during an air leak test. This makes it easy to perform an air leak test.

[0049] (3) The through hole 52 accommodates the filter member 53 so that the filter member 53 does not protrude from the mounting surface 46. This configuration prevents the filter member 53 from interfering with the jig 131 when the jig 131 covers the first insertion hole 51 and the through hole 52. This makes it easy to perform an air leak test.

[0050] (4) The outer peripheral edge of the mounting surface 46 has a flat shape over the entire circumferential direction. This configuration makes it easier to seal between the jig 131 and the mounting surface 46 compared to, for example, when part of the outer peripheral edge of the mounting surface 46 is uneven. This makes it easier to perform air leak testing.

[0051] (5) The through-hole 52 is exposed to the outside of the transmission housing 11. With this configuration, the filter member 53 can be replaced more easily than if the through-hole 52 were covered by the transmission housing 11.

[0052] This embodiment can be modified as follows. This embodiment and the following modifications can be combined and implemented as long as there is no technical contradiction. The first gear 21 and the second gear 22 are not limited to spur gears, and may be other gears such as worm gears and worm wheels. The transmission mechanism is not limited to one that includes a gear mechanism, a ball screw mechanism, and a sector gear. For example, the transmission mechanism may include only a gear mechanism. Furthermore, the transmission mechanism may additionally or alternatively include other mechanisms such as a belt mechanism.

[0053] The transmission housing 11 is not limited to having the first housing member 12, the second housing member 13, and the third housing member 14. For example, the transmission housing 11 may have only a single housing member, or may have two or four or more housing members.

[0054] The filter member 53 is not limited to the one including the base 121, the porous membrane 122, the cap 123, and the seal member 124 as in the above embodiment. The configuration of the filter member 53 can be changed as appropriate as long as it is breathable and waterproof.

[0055] The through hole 52 may open in a portion of the outer surface of the motor housing 33 that is covered by the transmission housing 11. The outer peripheral edge of the mounting surface 46 may be an uneven surface. Specifically, for example, the large diameter hole portion 111 of the through hole 52 may open not only to the mounting surface 46 but also to the outer peripheral surface 47 of the peripheral wall portion 43, thereby cutting out a portion of the outer peripheral edge of the mounting surface 46. In this case, an air leak test can be performed by providing the cylindrical portion 132 of the jig 131 with a portion that covers the cutout portion of the outer peripheral edge of the mounting surface 46, for example.

[0056] The through-hole 52 may be configured so that the filter member 53 protrudes from the mounting surface 46. For example, the through-hole 52 may have only the small diameter hole portion 112 and have a constant inner diameter over the entire axial length.

[0057] The through-hole 52 does not have to open to the mounting surface 46. The through-hole 52 only needs to open to an outer region of the outer surface of the motor housing 33, and may open to, for example, the outer peripheral surface 47 of the peripheral wall portion 43.

[0058] The mounting groove 56 does not have to be provided on the mounting surface 46 of the motor housing 33. In this case, a mounting groove may be provided in the plate portion 16 of the second housing member 13, and the seal member 57 surrounding the first insertion hole 51 may be attached to this mounting groove.

[0059] The actuator 1 may be used as a power source for devices other than a vehicle steering device. The technical concepts that can be understood from the above-described embodiments and modifications are described below. (Additional Note) The motor device may be configured so that gas is prevented from entering or leaving the motor device by blocking the insertion hole and the through-hole.

Claims

1. A motor device connected to a transmission device, the transmission device comprising: a transmission housing, a transmission member accommodated in the transmission housing, and lubricating oil filled within the transmission housing; the motor device comprising: an output shaft connected to the transmission member; a motor housing rotatably accommodating the output shaft, the motor housing having an insertion hole through which the output shaft is inserted and a through hole communicating between the inside and outside of the motor housing; and a filter member attached to the through hole, the outer surface of the motor housing including: a mounting surface into which the insertion hole opens and to which the transmission housing is attached, and an outer peripheral surface extending in the axial direction from the outer peripheral edge of the mounting surface, the mounting surface being provided with a mounting groove for attaching an annular seal member surrounding the insertion hole, the area of ​​the outer surface of the motor housing surrounded by the mounting groove being an inner region, and the area outside the mounting groove being an outer region, the through hole opening into the outer region.

2. An actuator comprising a motor device and a transmission device configured to transmit rotation of the motor device, wherein the transmission device comprises a transmission housing, a transmission member accommodated in the transmission housing, and lubricating oil filled within the transmission housing, wherein the motor device comprises: an output shaft connected to the transmission member, and a motor housing rotatably accommodating the output shaft, the motor housing having an insertion hole through which the output shaft is inserted and a through hole communicating between the inside and outside of the motor housing, and a filter member attached to the through hole, wherein the outer surface of the motor housing includes a mounting surface into which the insertion hole opens and to which the transmission housing is attached, and an outer peripheral surface extending in the axial direction from the outer peripheral edge of the mounting surface, wherein an annular seal member surrounding the insertion hole is provided between the transmission housing and the motor housing, and wherein the area of ​​the outer surface of the motor housing surrounded by the seal member is an inner region and the area outside the seal member is an outer region, and the through hole opens into the outer region.

3. An actuator according to claim 2, wherein the through-hole opens into the outer region within the mounting surface.

4. An actuator according to claim 3, wherein the through-hole accommodates the filter member so that the filter member does not protrude from the mounting surface.

5. An actuator according to any one of claims 2 to 4, wherein the outer peripheral edge of the mounting surface has a flat shape over the entire circumferential area of ​​the mounting surface.

6. An actuator according to any one of claims 2 to 4, wherein the through-hole is exposed to the outside of the transmission housing.

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