motor

Abstract

In a motor equipped with a power supply circuit board located outside the motor case, the electronic components mounted on the circuit board are properly protected. [Solution] The motor 2 comprises a rotor and a stator, a motor case 12 in which the rotor and stator are housed, a power supply circuit board 13 located outside the motor case 12, electronic components 33 and 34 mounted on the circuit board 13, and a cover 15 covering the electronic components 33 and 34. In the motor 2, the cover 15 makes it possible to properly protect the electronic components 33 and 34 mounted on the circuit board 13, thereby preventing damage to the electronic components 33 and 34 mounted on the circuit board 13.

Description

Technical Field

[0001] The present invention relates to a motor.

Background Art

[0002] Conventionally, a terminal structure of a motor used in a motor such as a stepping motor is known (for example, see Patent Document 1). The terminal structure described in Patent Document 1 includes a substrate holder attached to a terminal opening of a motor case and a power supply terminal substrate held by the substrate holder. Terminal holes into which terminal pins are inserted are formed in the terminal substrate, and the terminal pins inserted into the terminal holes are soldered and fixed to the terminal substrate. The substrate holder and the terminal substrate are disposed outside the motor case.

[0003] In the terminal structure described in Patent Document 1, the substrate holder is formed with a holding protrusion for holding the tip of the terminal substrate, holding claws for holding both end portions in the width direction of the terminal substrate, and a stopper claw that engages with the rear end portion of the terminal substrate to prevent the terminal substrate from falling off. When assembling the motor described in Patent Document 1, after attaching the terminal substrate to the substrate holder, the substrate holder and the terminal substrate are attached to the opening of the motor case. Thereafter, the terminal pins are soldered and fixed to the terminal substrate.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The inventors of the present invention have developed a motor equipped with a power supply circuit board located outside the motor case, such as the motor described in Patent Document 1. The circuit board is a rigid substrate, such as a glass epoxy substrate, and is formed in a flat plate shape. Terminal pins are electrically connected to the circuit board. Drive coils located inside the motor case are electrically connected to the terminal pins. The circuit board is held in a substrate holder attached to the motor case.

[0006] The inventors of the present invention are considering mounting relatively large electronic components or multiple electronic components on a circuit board in a motor currently under development. For example, the inventors are considering mounting relatively large electronic components such as drive ICs (Integrated Circuits) or multiple electronic components on a circuit board so that various motors can be controlled even with a single motor. In a motor under development, it is preferable that the electronic components mounted on the circuit board are appropriately protected to prevent damage to the electronic components mounted on the circuit board.

[0007] Therefore, the first object of the present invention is to provide a motor that has a power supply circuit board located outside the motor case and is capable of properly protecting the electronic components mounted on the circuit board.

[0008] Furthermore, when assembling the motor under development, the inventor decided to temporarily fix the circuit board to the circuit board holder, as described in Patent Document 1, then attach the circuit board holder and circuit board to the motor case, and finally solder terminal pins to the circuit board to fix it in place. In this case, if the circuit board holder is provided with retaining protrusions, retaining claws, and stopper claws, similar to the circuit board holder described in Patent Document 1, it becomes possible to temporarily fix the circuit board to the circuit board holder before attaching the circuit board holder and circuit board to the motor case. Therefore, handling of the circuit board holder and circuit board before attaching them to the motor case becomes easier.

[0009] However, in this case, in order to temporarily fix the circuit board to the board holder, it is necessary to elastically deform the stopper claw and engage it with the edge of the circuit board. In this case, when the stopper claw, which has elastically deformed to a predetermined position, engages with the edge of the circuit board, it may deform back to its original shape while making contact with the edge of the circuit board with excessive contact pressure, potentially causing the edge of the circuit board to be scraped. If the edge of the circuit board is scraped, it may generate shavings from the circuit board, which may cause some kind of malfunction.

[0010] Therefore, the second object of the present invention is to provide a motor that includes a power supply circuit board located outside the motor case and a board holder attached to the motor case and holding the circuit board, in which it is possible to temporarily fix the circuit board to the board holder, and which is capable of preventing the generation of shavings from the circuit board. [Means for solving the problem]

[0011] To solve the first problem described above, a motor according to one aspect of the present invention is characterized by comprising a rotor and a stator, a motor case housing the rotor and stator, a power supply circuit board disposed outside the motor case, electronic components mounted on the circuit board, and a cover covering the electronic components.

[0012] The motor in this embodiment is equipped with a cover that encloses the electronic components mounted on the circuit board. Therefore, in this embodiment, the cover can adequately protect the electronic components mounted on the circuit board. Consequently, in this embodiment, it is possible to prevent damage to the electronic components mounted on the circuit board.

[0013] Furthermore, in order to solve the second problem described above, a motor according to one aspect of the present invention comprises a rotor and a stator, a motor case housing the rotor and stator, a power supply circuit board disposed outside the motor case, and a circuit board holder attached to the motor case and holding the circuit board, wherein the circuit board is formed in a flat plate shape, and the circuit board holder is formed with press-fit fixing portions that contact the circuit board from both sides in the thickness direction of the circuit board with a predetermined contact pressure.

[0014] In this embodiment of the motor, the substrate holder has press-fit fixing portions that contact the circuit board with a predetermined contact pressure from both sides in the thickness direction of the circuit board. Therefore, in this embodiment, it is possible to temporarily fix the circuit board to the substrate holder. Furthermore, in this embodiment, since it is possible to temporarily fix the circuit board to the substrate holder by contacting the circuit board with a predetermined contact pressure from both sides in the thickness direction of the circuit board with the press-fit fixing portions, it is possible to prevent the circuit board from being scraped when temporarily fixing the circuit board to the substrate holder using the press-fit fixing portions. In other words, in this embodiment, even though it is possible to temporarily fix the circuit board to the substrate holder, it is possible to prevent the generation of scraping debris from the circuit board. [Effects of the Invention]

[0015] As described above, in one aspect of the present invention, in a motor equipped with a power supply circuit board located outside the motor case, it becomes possible to appropriately protect the electronic components mounted on the circuit board. Furthermore, in one aspect of the present invention, in a motor equipped with a power supply circuit board located outside the motor case and a circuit board holder attached to the motor case and holding the circuit board, it becomes possible to prevent the generation of shavings from the circuit board even if the circuit board can be temporarily fixed to the circuit board holder. [Brief explanation of the drawing]

[0016] [Figure 1] Figure 1 is a perspective view of a motor according to an embodiment of the present invention. [Figure 2] Figure 2 is a cross-sectional view of the motor shown in Figure 1. [Figure 3] FIG. 3 is a perspective view showing the state in which the cover is removed from the motor shown in FIG. 1 from different directions. [Figure 4] FIG. 4 is a perspective view showing the state in which the circuit board is removed from the motor shown in FIG. 3. [Figure 5] FIG. 5 is a side view of the circuit board shown in FIG. 1. [Figure 6] FIG. 6 is a cross-sectional view of the substrate holder shown in FIG. 1. [Figure 7] FIG. 7 is a perspective view showing the cover shown in FIG. 1 from different directions. [Figure 8] FIG. 8 is a cross-sectional view of the cover shown in FIG. 7.

BEST MODE FOR CARRYING OUT THE INVENTION

[0017] Hereinafter, embodiments of the present invention will be described with reference to the drawings. [[ID=:25]]

[0018] (Overall Configuration of Motor) FIG. 1 is a perspective view of a motor 2 according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of the motor 2 shown in FIG. 1.

[0019] The motor 2 of this embodiment is a geared motor. The motor 2 includes a motor body 3 and a reduction gear mechanism 4. The reduction gear mechanism 4 includes a rotary shaft 5 that serves as an output shaft of the motor 2 and a reduction gear train 6. The reduction gear train 6 includes a plurality of gears. The motor body 3 is a stepping motor. Specifically, the motor body 3 is a so-called PM type stepping motor. Also, the motor body 3 is a two-phase stepping motor. The motor body 3 includes a rotor 10 having drive magnets 9 and a stator 11 disposed on the outer peripheral side of the drive magnets 9.

[0020] Furthermore, the motor 2 includes a motor case 12 that houses the rotor 10 and stator 11, a power supply circuit board 13 located outside the motor case 12, a circuit board holder 14 that holds the circuit board 13, and a cover 15 attached to the circuit board holder 14. In the following description, the axial direction of the rotor 10 (Z direction in Figure 1, etc.) will be referred to as the "up and down direction," the Y direction in Figure 1, etc., which is perpendicular to the up and down direction, will be referred to as the "left and right direction," and the X direction in Figure 1, etc., which is perpendicular to both the up and down direction and the left and right direction, will be referred to as the "front and back direction." The left and right direction is the radial direction of the rotor 10, perpendicular to the axial direction of the rotor 10. The front and back direction is also the radial direction of the rotor 10, perpendicular to the axial direction of the rotor 10. The up and down direction is also the axial direction of the rotation axis 5.

[0021] Furthermore, in the following explanation, the side in the Z1 direction as shown in Figure 1, which is one side in the vertical direction, will be referred to as the "upper" side, the side in the Z2 direction as shown in Figure 1, which is the opposite side of the upper side, will be referred to as the "lower" side, the side in the Y1 direction as shown in Figure 1, which is one side in the horizontal direction, will be referred to as the "right" side, and the side in the Y2 direction as shown in Figure 1, which is the opposite side of the right side, will be referred to as the "left" side. In this embodiment, the upper side (Z1 direction side) is the first direction side, which is one side in the axial direction of the rotor 10, and the lower side (Z2 direction side) is the second direction side, which is the opposite side of the first direction side (the other side in the axial direction of the rotor 10). Also, in this embodiment, the upper side is the output side of the motor 2, and the lower side is the non-output side of the motor 2.

[0022] As described above, the motor body 3 comprises a rotor 10 and a stator 11. The rotor 10 has a rotating shaft 16 to which the drive magnet 9 is fixed. The rotating shaft 16 is formed in a cylindrical shape. A fixed shaft 17 is positioned on the inner circumference side of the rotating shaft 16. The fixed shaft 17 is positioned so that its axial direction coincides with its vertical direction. The lower end of the fixed shaft 17 is held to the bottom (lower surface) of the motor case 12. The upper end of the fixed shaft 17 is held to the end plate 27, which will be described later.

[0023] The rotating shaft 16 rotates with the vertical direction as the axis of rotation. The upper end portion of the rotating shaft 16 is an output shaft 16b that protrudes upward from the stator 11. The reduction gear train 6 is connected to the output shaft 16b. The drive magnet 9 is a permanent magnet and is formed in a substantially cylindrical shape. The drive magnet 9 is fixed to the outer circumferential surface of the lower end portion of the rotating shaft 16. On the outer circumferential surface of the drive magnet 9, north poles and south poles are formed alternately along the circumferential direction of the rotor 10.

[0024] The stator 11 comprises an A-phase stator section 18 and a B-phase stator section 19 that overlap in the vertical direction. The stator section 18 is located above the stator section 19. The stator section 18 is located on the outer circumference of the upper end portion of the drive magnet 9, and the stator section 19 is located on the outer circumference of the lower end portion of the drive magnet 9. The stator section 18 comprises a drive coil 20 and a stator core 21. The stator section 19 comprises a drive coil 22 and a stator core 23. The reduction gear train 6 is located above the stator 11 and the drive magnet 9.

[0025] The drive coil 20 is wound around bobbin 24, and the drive coil 22 is wound around bobbin 25. That is, the stator 11 comprises bobbins 24 and 25. The stator cores 21 and 23 have multiple pole teeth formed on them that face the outer circumferential surface of the drive magnet 9. The drive coil 20 and bobbin 24 are positioned outside the multiple pole teeth of the stator core 21 in the radial direction of the rotor 10. The drive coil 22 and bobbin 25 are positioned outside the multiple pole teeth of the stator core 23 in the radial direction of the rotor 10.

[0026] The stator core 21 is composed of an outer stator core having a disc-shaped end plate portion positioned above the drive coil 20 and an inner stator core having a disc-shaped end plate portion positioned below the drive coil 20. The stator core 23 is composed of an outer stator core having a disc-shaped end plate portion positioned below the drive coil 22 and an inner stator core having a disc-shaped end plate portion positioned above the drive coil 22.

[0027] The stator 11 also has a plurality of terminal pins 26 to which the drive coils 20 and 22 are electrically connected. In this embodiment, the stator 11 has five terminal pins 26. A terminal block 24b is formed on the bobbin 24 to hold the five terminal pins 26. The terminal block 24b is formed at the upper right end of the bobbin 24. The terminal block 24b is formed in the shape of a rectangular parallelepiped that protrudes to the right. The terminal block 24b is also formed in the shape of a rectangular parallelepiped that is elongated in the front-to-back direction. The five terminal pins 26 held by the terminal block 24b are arranged with a constant spacing in the front-to-back direction. The terminal pins 26 are electrically connected to the circuit board 13.

[0028] As shown in Figure 2, the terminal pin 26 is composed of a retained portion 26b that is held by the terminal block 24b and a coil fixing portion 26d to which the ends of the drive coils 20 and 22 are fixed. The retained portion 26b is formed in a straight line extending in the left-right direction. The right end of the retained portion 26b is positioned to the right of the terminal block 24b, and the left end of the retained portion 26b is positioned to the right of the terminal block 24b. The right end (tip) of the retained portion 26b is soldered and fixed to the circuit board 13. The coil fixing portion 26d is formed in a straight line extending diagonally upward and to the right from the left end of the retained portion 26b. The ends of the drive coils 20 and 22 are soldered and fixed to the coil fixing portion 26d in a wound state.

[0029] The motor case 12 comprises a cylindrical case body 28 with an open top and a bottom, and a disc-shaped bottom cover 29 fixed to the bottom surface (lower surface) of the case body 28. In this embodiment, the motor case 12 is composed of the case body 28 and the bottom cover 29. The motor case 12 constitutes the outer circumferential surface of the motor body 3 and the outer circumferential surface of the motor 2. The motor case 12 also houses the reduction gear train 6 and the lower end portion of the rotating shaft 5.

[0030] In this configuration, the case body 28 is formed integrally with the outer stator core of the stator core 23. The end plate portion of the outer stator core of the stator core 23 constitutes the bottom (lower surface) of the case body 28. Alternatively, the case body 28 may be formed separately from the outer stator core of the stator core 23. In this case, for example, the end plate portion of the outer stator core of the stator core 23 is positioned above the bottom of the case body 28.

[0031] The case body 28 has an opening 28b that is recessed downward from the upper end surface of the case body 28 and penetrates the case body 28 in the radial direction of the rotor 10. In other words, the motor case 12 has an opening 28b. The opening 28b is formed at the right end of the motor case 12. When viewed from the right side, the outer shape of the opening 28b is rectangular. An end plate 27 is fixed to the upper end of the case body 28. In other words, the motor 2 is equipped with an end plate 27 fixed to the upper end of the motor case 12. The end plate 27 is formed in a flat shape with the vertical direction as the thickness direction. The upper surface of the end plate 27 is a plane perpendicular to the vertical direction. The upper part of the rotating shaft 5 protrudes above the upper surface of the end plate 27.

[0032] (Configuration of circuit board, board holder, and cover) Figure 3 is a perspective view of the motor 2 shown in Figure 1 with the cover 15 removed, from a different direction. Figure 4 is a perspective view of the motor 2 shown in Figure 3 with the circuit board 13 removed. Figure 5 is a side view of the circuit board 13 shown in Figure 1. Figure 6 is a cross-sectional view of the board holder 14 shown in Figure 1. Figure 7 is a perspective view of the cover 15 shown in Figure 1 from a different direction. Figure 8 is a cross-sectional view of the cover 15 shown in Figure 7.

[0033] The circuit board 13 serves the function of supplying power to the drive coils 20 and 22. The circuit board 13 is a rigid substrate such as a glass epoxy substrate. The circuit board 13 is formed in a flat plate shape. The circuit board 13 is arranged parallel to the vertical direction. That is, the circuit board 13 is formed in a flat plate shape arranged parallel to the axial direction of the rotor 10. The circuit board 13 is formed in a rectangular flat plate shape with the vertical direction as the longer side. The circuit board 13 is located on the right side of the motor case 12. The thickness direction of the circuit board 13 coincides with the left-right direction. That is, the thickness direction of the circuit board 13 coincides with the radial direction of the rotor 10. The vertical length of the circuit board 13 is longer than the vertical length of the motor case 12. The lower end surface of the circuit board 13 is located below the lower surface of the motor case 12.

[0034] The circuit board 13 has a retained portion 13b that protrudes upward and a retained portion 13c that protrudes outward in the front-rear direction. The retained portions 13c are formed at two locations on both sides of the circuit board 13 in the front-rear direction. The retained portion 13b constitutes the upper end of the circuit board 13. The retained portion 13b is formed in a rectangular shape with the front-rear direction as the longer side. The upper end surface 13d of the retained portion 13b is the upper end surface of the circuit board 13. The upper end surface 13d is a plane perpendicular to the vertical direction.

[0035] The retained portion 13c constitutes both ends of the circuit board 13 in the front-to-back direction. The retained portion 13c is formed over a relatively wide area in the vertical direction and is formed in an elongated rectangular shape with the vertical direction as the longer side. The upper end surface 13e and the lower end surface 13f of the retained portion 13c are planes perpendicular to the vertical direction. The upper end surface 13e is located below the retained portion 13b. The lower end surface 13f is located above the lower end surface of the circuit board 13.

[0036] The circuit board 13 has five pin placement holes 13g formed therein, where the right end of the retained portion 26b of the terminal pin 26 is positioned. The pin placement holes 13g are round holes that penetrate the circuit board 13 in the left-right direction. The five pin placement holes 13g are formed at the upper end of the circuit board 13. The pin placement holes 13g are positioned below the retained portion 13b. The five pin placement holes 13g are arranged with a constant spacing in the front-back direction.

[0037] A connector 31 is mounted on the circuit board 13. The connector 31 is mounted on the right side of the lower end of the circuit board 13. The socket of the connector 31 faces downwards. The mating connector 32 (see Figure 2) is inserted into the connector 31 from below. The mating connector 32, once inserted into the connector 31, is pulled out downwards. In other words, the mating connector 32 is inserted into and removed from the connector 31 in the axial direction of the rotor 10.

[0038] Furthermore, multiple electronic components 33 and 34 are mounted on the circuit board 13. That is, the motor 2 is equipped with electronic components 33 and 34 mounted on the circuit board 13. The electronic components 33 and 34 are mounted on the circuit board 13 below the pin placement holes 13g. For example, one drive IC is mounted on the circuit board 13 as electronic component 33. In addition, multiple electronic components 34 other than the drive IC are mounted on the circuit board 13. The electronic components 33 and 34 are mounted on the right side of the circuit board 13. Note that the illustration of electronic component 34 is omitted in Figure 2. Also, some of the electronic components 33 and 34 may be mounted on the left side of the circuit board 13.

[0039] The circuit board holder 14 is attached to the motor case 12. Specifically, the circuit board holder 14 is attached to the opening 28b of the motor case 12 and is located on the right side of the motor case 12. The circuit board holder 14 is a resin molded product manufactured by resin molding using a mold. The circuit board holder 14 is formed in a substantially rectangular parallelepiped shape. The circuit board holder 14 holds the upper portion of the circuit board 13. The upper end surface of the circuit board holder 14 is located at approximately the same position as the upper surface of the end plate 27 in the vertical direction. The lower end of the circuit board holder 14 is located above the lower end of the motor case 12. A portion of the lower surface of the circuit board holder 14 is in contact with the lower surface of the opening 28b (see Figure 2).

[0040] The substrate holder 14 has a first inner mounting portion 14b positioned inside the inner circumferential surface of the upper end of the motor case 12, a second inner mounting portion 14c positioned inside the inner circumferential surface of the lower end of the motor case 12, and an outer mounting portion 14d positioned outside the outer circumferential surface of the motor case 12. The first inner mounting portion 14b and the outer mounting portion 14d are formed on both sides of the substrate holder 14 in the front-rear direction. The second inner mounting portion 14c is formed at the lower end of the substrate holder 14.

[0041] The first inner mounting portion 14b protrudes toward the left. The outer mounting portion 14d is positioned below the first inner mounting portion 14b. The first inner mounting portion 14b and the outer mounting portion 14d are positioned so as to sandwich the motor case 12 at the edge of the opening 28b. The left end of the first inner mounting portion 14b engages with the bobbin 24. The second inner mounting portion 14c is formed in a curved shape that forms an arc when viewed from above. The lower end of the second inner mounting portion 14c is positioned below the opening 28b and inside the inner circumferential surface of the motor case 12 (see Figure 2).

[0042] The substrate holder 14 has a substrate-facing surface 14e that faces the left side of the circuit board 13. The substrate-facing surface 14e is a plane perpendicular to the left-right direction and faces to the right. The substrate holder 14 also has five pin placement holes 14f where a portion of the held portion 26b of the terminal pins 26 is placed. The pin placement holes 14f are round holes that penetrate the substrate holder 14 in the left-right direction. The right end of the pin placement holes 14f is open on the substrate-facing surface 14e. The pin placement holes 14f are located to the right of the terminal block 24b. The five pin placement holes 14f are arranged with a constant spacing in the front-to-back direction.

[0043] The substrate holder 14 includes a substrate contact portion 14h on which a substrate contact surface 14g is formed that contacts the right side of the held portion 13b of the circuit board 13, and two substrate contact portions 14k on which substrate contact surfaces 14j are formed that contact the right side of the held portion 13c of the circuit board 13. The substrate contact portion 14h is formed in the shape of a flat plate that protrudes downward from the upper end of the substrate holder 14. The substrate contact portions 14k are formed in the shape of a flat plate that protrudes inward in the front-rear direction from both ends of the substrate holder 14 in the front-rear direction. The substrate contact portions 14k are located below the substrate contact portion 14h.

[0044] The substrate contact surfaces 14g and 14j are planes perpendicular to each other in the left-right direction. As shown in Figure 6, the substrate contact portion 14h has an inclined surface 14n that connects to the lower end of the substrate contact surface 14g. The substrate contact portion 14k has an inclined surface 14p that connects to the lower end of the substrate contact surface 14j. The inclined surfaces 14n and 14p are planar inclined surfaces that slope to the right as they are directed downwards. The inclined surface 14n serves to guide the circuit board 13 to the left side of the substrate contact surface 14g. The inclined surface 14p serves to guide the circuit board 13 to the left side of the substrate contact surface 14j.

[0045] To the left of the substrate contact portion 14h, a through-hole 14r is formed for the mold used to form the substrate contact portion 14h when manufacturing the substrate holder 14 by resin molding. To the left of the substrate contact portion 14k, a through-hole 14s is formed for the mold used to form the substrate contact portion 14k when manufacturing the substrate holder 14 by resin molding (see Figure 4). The through-holes 14r and 14s are through-holes that penetrate the substrate holder 14 in the left-right direction. The right ends of the through-holes 14r and 14s open at the substrate-facing surface 14e. The right end of the through-hole 14r is surrounded by the substrate-facing surface 14e from both sides in the front-rear direction and from below. The right end of the through-hole 14s is surrounded by the substrate-facing surface 14e from both sides in the up-down direction and from the inside in the front-rear direction.

[0046] The substrate contact surfaces 14g and 14j are in contact with the right side of the circuit board 13 with a predetermined contact pressure. In addition, at least the portions of the substrate opposing surface 14e around the through holes 14r and 14s are in contact with the left side of the circuit board 13 with a predetermined contact pressure. In this embodiment, the substrate contact portion 14h and the portion of the substrate opposing surface 14e around the through hole 14r form a press-fit fixing portion 14t that contacts the circuit board 13 from both sides in the thickness direction with a predetermined contact pressure. In addition, the substrate contact portion 14k and the portion of the substrate opposing surface 14e around the through hole 14s form a press-fit fixing portion 14v that contacts the circuit board 13 from both sides in the thickness direction with a predetermined contact pressure. That is, the substrate holder 14 has press-fit fixing portions 14t and 14v formed thereon.

[0047] The retained portion 13b is lightly press-fitted and held in place by the press-fit fixing portion 14t. The retained portion 13c is lightly press-fitted and held in place by the press-fit fixing portion 14v. In this embodiment, the press-fit fixing portion 14t is a first press-fit fixing portion that holds the upper end of the circuit board 13 (i.e., one end of the circuit board 13 in the axial direction of the rotor 10). The press-fit fixing portion 14v is a second press-fit fixing portion that holds both ends of the circuit board 13 in the front-rear direction (i.e., both ends of the circuit board 13 in the direction perpendicular to the axial direction of the rotor 10 and the thickness direction of the circuit board 13).

[0048] A restricting surface 14w is formed on the upper side of the press-fit fixing portion 14t to restrict the upward movement of the circuit board 13. The restricting surface 14w is a plane perpendicular to the vertical direction. The upper end surface 13d of the circuit board 13 faces the restricting surface 14w. Also, the upper end surface 13d of the circuit board 13 is in contact with the restricting surface 14w. In this embodiment, the restricting surface 14w is a holder-side restricting surface that restricts the movement of the circuit board 13 to the other side in the insertion / removal direction of the mating connector 32. The upper end surface 13d of the circuit board 13 is a second board-side restricting surface that faces the holder-side restricting surface 14w. In other words, a second board-side restricting surface is formed on the circuit board 13.

[0049] Furthermore, the restricting surface 14w in this embodiment is also the holder-side contact surface that the upper end surface 13d of the circuit board 13 contacts. That is, the substrate holder 14 has a holder-side contact surface formed on one end surface of the circuit board 13 in the axial direction of the rotor 10, which contacts the end surface of the circuit board 13 on the press-fit fixing portion 14t side.

[0050] The cover 15 is formed in a vertically elongated rectangular tube shape, with openings at both ends in the vertical direction. The cover 15 covers the electronic components 33 and 34 mounted on the circuit board 13. Both sides of the cover 15 in the left-right direction are planes perpendicular to each other in the left-right direction. The vertical length of the cover 15 is longer than the vertical length of the motor case 12. Also, the vertical length of the cover 15 is shorter than the vertical length of the circuit board 13. The cover 15 is attached to the board holder 14 from below. The upper end of the cover 15 is attached to the lower end of the board holder 14. The cover 15 is fixed to the board holder 14 by a snap fit.

[0051] The cover 15 is composed of a first cover portion 15b which constitutes the right side of the cover 15, a second cover portion 15c which constitutes the left side of the cover 15, and two elastically deformable engaging pieces 15d which snap-fit ​​to the substrate holder 14. The first cover portion 15b is formed in the shape of a rectangular groove with openings at both ends in the vertical direction and on the left side. The second cover portion 15c is formed in the shape of a rectangular groove with openings at both ends in the vertical direction and on the right side. Below the substrate holder 14, the circuit board 13 is held by the second cover portion 15c.

[0052] The upper end surface 15g of the second cover portion 15c is positioned below the upper end surface of the first cover portion 15b. The lower end surface of the first cover portion 15b and the lower end surface of the second cover portion 15c are positioned at the same location in the vertical direction. The upper end surface of the first cover portion 15b and the upper end surface 15g of the second cover portion 15c are planes perpendicular to each other in the vertical direction. The lower end surface of the cover 15 is also a plane perpendicular to each other in the vertical direction. The engaging piece 15d protrudes upward from the second cover portion 15c. The engaging piece 15d is formed on both sides of the second cover portion 15c in the front-rear direction. The engaging piece 15d is elastically deformable in the front-rear direction.

[0053] The upper end surface of the first cover portion 15b is positioned below the pin arrangement hole 13g in the vertical direction, and above the uppermost electronic components 33 and 34. The upper end surface 15g of the second cover portion 15c is positioned at the same location as the lower surface of the motor case 12 (i.e., the lower surface of the bottom cover 29) in the vertical direction. In this embodiment, the outer diameter of the case body 28 is larger than the outer diameter of the bottom cover 29. The left side of the cover 15 (i.e., the left side of the second cover portion 15c) is positioned slightly to the right of the right edge of the bottom cover 29. Therefore, the upper end surface 15g of the second cover portion 15c does not contact the lower surface of the motor case 12.

[0054] The lower end surface of the cover 15 is positioned at approximately the same location as the lower end surface of the circuit board 13. The first cover portion 15b covers the circuit board 13 and the electronic components 33 and 34 mounted on it from the right side, in the range from below the pin placement holes 13g and above the uppermost electronic components 33 and 34 to the lower end of the circuit board 13. The second cover portion 15b covers the circuit board 13 from both sides and the left side in the front-to-back direction, in the range from the lower surface of the motor case 12 to the lower end of the circuit board 13.

[0055] On both front-to-rear sides of the second cover portion 15c, substrate holding grooves 15e are formed for holding the retained portion 13c of the circuit board 13. In other words, the cover 15 has substrate holding grooves 15e for holding both ends of the circuit board 13 in the front-to-rear direction. The substrate holding grooves 15e are recessed from the inner surface of the front-to-rear side of the second cover portion 15c toward the outside in the front-to-rear direction. Furthermore, the substrate holding grooves 15e are formed in a straight line parallel to the vertical direction with an open top. Specifically, the substrate holding grooves 15e are formed in a rectangular groove shape parallel to the vertical direction with an open top. Most of the retained portion 13c, excluding the top end, fits into the substrate holding grooves 15e.

[0056] Both sides of the substrate holding groove 15e in the left-right direction are planes perpendicular to the left-right direction. The right side of the held portion 13c is in light contact with the right side of the substrate holding groove 15e, or is facing it with a small gap between them. The left side of the held portion 13c is in light contact with the left side of the substrate holding groove 15e, or is facing it with a small gap between them.

[0057] The lower surface of the substrate holding groove 15e is a restricting surface 15f for restricting the downward movement of the circuit board 13. The restricting surface 15f is a plane perpendicular to the vertical direction. The lower end surface 13f of the held portion 13c of the circuit board 13 faces the restricting surface 15f. Also, the lower end surface 13f is in contact with the restricting surface 15f. In this embodiment, the restricting surface 15f is a cover-side restricting surface for restricting the movement of the circuit board 13 to one side in the insertion / removal direction of the mating connector 32. The lower end surface 13f of the circuit board 13 is a first substrate-side restricting surface that faces the restricting surface 15f, which is the cover-side restricting surface. That is, a first substrate-side restricting surface is formed on the circuit board 13.

[0058] During the assembly of motor 2, the stator 11 is housed in the motor case 12 from above. The circuit board 13 is then attached to the circuit board holder 14 from below. The circuit board 13 attached to the circuit board holder 14 is temporarily fixed and held in place by the press-fit fixing parts 14t and 14v. The circuit board holder 14 that holds the circuit board 13 is then attached to the opening 28b of the motor case 12 from the right side. At this time, the retained parts 26b of the terminal pins 26 are inserted into the pin placement holes 14f of the circuit board holder 14 and the pin placement holes 13g of the circuit board 13. The circuit board 13 and the retained parts 26b are then soldered together from the right side to secure them. The cover 15 is then attached to the circuit board holder 14 from below. At this time, the cover 15 is slid linearly upward relative to the circuit board 13.

[0059] (Main effects of this form) As explained above, in this embodiment, the motor 2 is equipped with a cover 15 that covers the electronic components 33 and 34 mounted on the circuit board 13. Therefore, in this embodiment, the cover 15 can properly protect the electronic components 33 and 34 mounted on the circuit board 13. Consequently, in this embodiment, it is possible to prevent damage to the electronic components 33 and 34 mounted on the circuit board 13.

[0060] In this embodiment, the substrate holder 14, which is formed separately from the cover 15, holds only the upper portion of the circuit board 13. Therefore, in this embodiment, it is possible to change only the vertical length of the cover 15 according to the vertical length of the circuit board 13. Consequently, in this embodiment, it is possible to use a common substrate holder 14 even if the length of the circuit board 13 changes.

[0061] In this embodiment, the cover 15 has a restricting surface 15f formed on it to restrict the movement of the circuit board 13 to one side in the insertion / removal direction of the mating connector 32, and the board holder 14 has a restricting surface 14w formed on it to restrict the movement of the circuit board 13 to the other side in the insertion / removal direction of the mating connector 32. In addition, in this embodiment, the circuit board 13 has a lower end surface 13f facing the restricting surface 15f and an upper end surface 13d facing the restricting surface 14w.

[0062] Therefore, in this embodiment, the cover 15 and the board holder 14 can receive the force acting on the circuit board 13 when the mating connector 32 is inserted into or removed from the connector 31. Consequently, in this embodiment, it is possible to prevent damage to the connection portion (the portion that is soldered and fixed) between the circuit board 13 and the terminal pins 26 due to the insertion and removal of the mating connector 32 from the connector 31. Furthermore, in this embodiment, it is possible to position the circuit board 13 in the insertion and removal direction (i.e., the up and down direction) of the mating connector 32 with respect to the cover 15 and the board holder 14.

[0063] In this embodiment, the cover 15 has substrate holding grooves 15e formed therein for holding both ends of the circuit board 13 in the front-rear direction. The substrate holding grooves 15e are open at the top and are formed in a straight line parallel to the vertical direction. Therefore, in this embodiment, even if the cover 15 is attached to the substrate holder 14 from below, the circuit board 13 can be positioned in the left-right direction using the substrate holding grooves 15e.

[0064] In this embodiment, the substrate holder 14 has press-fit fixing portions 14t and 14v that contact the circuit board 13 with a predetermined contact pressure from both sides in the left-right direction, which is the thickness direction of the circuit board 13. Therefore, in this embodiment, it is possible to temporarily fix the circuit board 13 to the substrate holder 14. Furthermore, in this embodiment, since it is possible to temporarily fix the circuit board 13 to the substrate holder 14 by contacting the circuit board 13 with a predetermined contact pressure from both sides in the thickness direction of the circuit board 13 with the press-fit fixing portions 14t and 14v, it is possible to prevent the circuit board 13 from being scraped when temporarily fixing the circuit board 13 to the substrate holder 14 using the press-fit fixing portions 14t and 14v. In other words, in this embodiment, even though it is possible to temporarily fix the circuit board 13 to the substrate holder 14, it is possible to prevent the generation of scraping debris from the circuit board 13.

[0065] In this embodiment, the substrate holder 14 has a press-fit fixing portion 14t that holds the upper end of the circuit board 13, and press-fit fixing portions 14v that hold both ends of the circuit board 13 in the front-rear direction. In other words, in this embodiment, the circuit board 13 is held at three points on the substrate holder 14. Therefore, in this embodiment, it is possible to stabilize the state of the circuit board 13 when it is temporarily fixed to the substrate holder 14.

[0066] In this embodiment, the substrate holder 14 has a restricting surface 14w that contacts the upper end surface 13d of the circuit board 13. Therefore, in this embodiment, the temporary fixing of the circuit board 13 to the substrate holder 14 is completed by pushing the circuit board 13 upward against the substrate holder 14 until the upper end surface 13d of the circuit board 13 contacts the restricting surface 14w. Thus, in this embodiment, the temporary fixing of the circuit board 13 to the substrate holder 14 can be easily performed.

[0067] (Other embodiments) The above-described embodiments are examples of preferred embodiments of the present invention, but are not limited thereto, and various modifications can be made without altering the essence of the invention.

[0068] In the above-described configuration, the upper end surface 15g of the second cover portion 15c may be in contact with the lower surface of the motor case 12. In this case, the upper end surface 15g becomes the cover-side contact surface that contacts the lower surface of the motor case 12. In this case, it becomes possible to stabilize the state of the cover 15 attached to the substrate holder 14. Also, in the above-described configuration, the vertical length of the circuit board 13 may be equal to the vertical length of the motor case 12, or it may be shorter than the vertical length of the motor case 12.

[0069] In the above-described configuration, the cover 15 may be attached to the substrate holder 14 from the right side. In this case, the substrate holding groove 15e is not formed in the cover 15. Also in this case, for example, the substrate holder 14 may hold the entire circuit board 13 in the vertical direction. Furthermore, in the above-described configuration, the connector 31 may be mounted on the left side of the circuit board 13. In this case, by mounting the connector 31 on the left side of the circuit board 13 so that it overlaps with the electronic components 33 and 34 in the left-right direction, it becomes possible to shorten the length of the circuit board 13. Therefore, it becomes possible to shorten the length of the cover 15.

[0070] In the above-described configuration, the thickness direction of the circuit board 13 may coincide with the vertical direction, which is the axial direction of the rotor 10, or it may be slightly inclined with respect to the vertical direction. In this case, the circuit board 13 protrudes radially outward from the rotor 10. For example, the circuit board 13 protrudes to the right. In this case, for example, the cover 15 is attached to the board holder 14 from the right side. Also, when the circuit board 13 protrudes to the right, the entire circuit board 13 may be housed in the board holder 14 located below the circuit board 13. In this case, for example, the cover 15 is attached to the board holder 14 from above.

[0071] In the above-described configuration, the circuit board 13 may be held by light press-fitting at one or two locations on the board holder 14. That is, in the above-described configuration, the press-fit fixing portion 14t or press-fit fixing portion 14v does not need to be formed on the board holder 14. Furthermore, in the above-described configuration, the circuit board 13 may be held by light press-fitting at four or more locations on the board holder 14. Furthermore, in the above-described configuration, the press-fit fixing portion 14t and press-fit fixing portion 14v do not need to be formed on the board holder 14.

[0072] In the above-described configuration, the substrate holder 14 and the cover 15 may be integrally formed. Also, in the above-described configuration, the motor 2 does not need to have a cover 15. Furthermore, in the above-described configuration, the motor body 3 may be a motor other than a stepping motor. Also, in the above-described configuration, the motor 2 does not need to be a geared motor. That is, the motor 2 does not need to have a reduction gear mechanism 4.

[0073] (Configuration of this technology) Furthermore, this technology can be configured as follows: (1) A motor comprising a rotor and a stator, a motor case housing the rotor and the stator, a power supply circuit board disposed outside the motor case, electronic components mounted on the circuit board, and a cover covering the electronic components. (2) The motor according to (1), characterized in that the circuit board is formed in the shape of a flat plate and arranged parallel to the axial direction of the rotor. (3) The motor case is equipped with a circuit board holder that is attached to the motor case and holds the circuit board, and the cover is attached to it, The motor according to (2), characterized in that the substrate holder holds one side of the circuit board in the axial direction of the rotor. (4) A connector is mounted on the circuit board, The connector is connected to and disconnected from the mating connector in the axial direction of the rotor. The cover has a cover-side restricting surface formed to restrict the movement of the circuit board to one side in the insertion / removal direction of the mating connector. The substrate holder is formed with a holder-side restricting surface for restricting the movement of the circuit board to the other side in the insertion / removal direction of the mating connector. The motor according to (3), characterized in that the circuit board has a first substrate-side restricting surface facing the cover-side restricting surface and a second substrate-side restricting surface facing the holder-side restricting surface. (5) If one side of the rotor in the axial direction is designated as the first direction side, and the other side of the rotor in the axial direction opposite to the first direction side is designated as the second direction side, The cover is attached to the substrate holder from the second direction side. The cover has substrate holding grooves formed therein for holding both ends of the circuit board in a direction perpendicular to the axial direction of the rotor and the thickness direction of the circuit board. The motor according to (3) or (4), characterized in that the substrate holding groove is open on the first direction side and is formed in a straight line parallel to the axial direction of the rotor. (6) If one side of the rotor in the axial direction is designated as the first direction side, and the other side of the rotor in the axial direction opposite to the first direction side is designated as the second direction side, The cover is attached to the substrate holder from the second direction side. The motor according to any one of (3) to (5), characterized in that the cover has a cover-side contact surface that contacts the end face on the second direction side of the motor case. (7) A motor comprising a rotor and a stator, a motor case housing the rotor and the stator, a power supply circuit board located outside the motor case, and a circuit board holder attached to the motor case and holding the circuit board, The circuit board is formed in a flat plate shape, The motor is characterized in that the substrate holder has press-fit fixing portions formed therein that contact the circuit board with a predetermined contact pressure from both sides in the thickness direction of the circuit board. (8) The motor according to (7), characterized in that the circuit board is arranged parallel to the axial direction of the rotor. (9) The motor according to (8), characterized in that the substrate holder has a first press-fit fixing portion which holds one end of the circuit board in the axial direction of the rotor, and a second press-fit fixing portion which holds both ends of the circuit board in directions perpendicular to the axial direction of the rotor and the thickness direction of the circuit board. (10) The motor according to (9), characterized in that the substrate holder has a holder-side contact surface formed thereon, which is one end face of the circuit board in the axial direction of the rotor, and which contacts the end face of the circuit board on the side of the first press-fit fixing portion.

[0074] In this technology, for example, the circuit board is formed in the shape of a flat plate that is arranged parallel to the axial direction of the rotor.

[0075] In this technology, the motor is preferably equipped with a circuit board holder that is attached to the motor case, holds the circuit board, and to which a cover is attached, and the circuit board holder preferably holds one side of the circuit board in the axial direction of the rotor. With this configuration, it becomes possible to change only the length of the cover in the axial direction of the rotor according to the length of the circuit board in the axial direction of the rotor. Therefore, it becomes possible to use a common circuit board holder even if the length of the circuit board in the axial direction of the rotor changes.

[0076] In this technology, it is preferable that a connector is mounted on the circuit board, a mating connector is inserted into and removed from the connector in the axial direction of the rotor, the cover has a cover-side restricting surface formed to restrict the movement of the circuit board to one side in the insertion / removal direction of the mating connector, the board holder has a holder-side restricting surface formed to restrict the movement of the circuit board to the other side in the insertion / removal direction of the mating connector, and the circuit board has a first board-side restricting surface facing the cover-side restricting surface and a second board-side restricting surface facing the holder-side restricting surface.

[0077] With this configuration, the cover and board holder can absorb the force acting on the circuit board when the mating connector is inserted into or removed from the other connector. Therefore, it is possible to prevent damage to the connection point (the part that is soldered and fixed) between the power supply circuit board and the terminal pins due to the insertion and removal of the mating connector. Furthermore, with this configuration, it is possible to position the circuit board relative to the cover and board holder in the direction in which the mating connector is inserted or removed.

[0078] In this technology, for example, if one side of the rotor in the axial direction is designated as the first direction, and the other side of the rotor in the axial direction opposite to the first direction is designated as the second direction, the cover is attached to the substrate holder from the second direction, and the cover has substrate holding grooves formed therein to hold both ends of the circuit board in a direction perpendicular to the rotor axial direction and the thickness direction of the circuit board, and the substrate holding grooves are formed in a straight line parallel to the rotor axial direction and open on the first direction side. In this case, even if the cover is attached to the substrate holder from the second direction, it becomes possible to position the circuit board in the thickness direction of the circuit board using the substrate holding grooves.

[0079] In this technology, if one side of the rotor in the axial direction is designated as the first direction side, and the other side of the rotor in the axial direction opposite to the first direction side is designated as the second direction side, then it is preferable that the cover is attached to the substrate holder from the second direction side, and the cover has a cover-side contact surface that contacts the end face of the motor case on the second direction side. With this configuration, since the end face of the motor case on the second direction side and the cover-side contact surface of the cover are in contact, it becomes possible to stabilize the state of the cover attached to the substrate holder.

[0080] In this technology, for example, the circuit board is arranged parallel to the axial direction of the rotor.

[0081] In this technology, it is preferable that the substrate holder has a first press-fit fixing portion that holds one end of the circuit board in the axial direction of the rotor, and a second press-fit fixing portion that holds both ends of the circuit board in directions perpendicular to the axial direction of the rotor and the thickness direction of the circuit board. With this configuration, it becomes possible to hold the circuit board at three locations on the substrate holder. Therefore, it becomes possible to stabilize the state of the circuit board when it is temporarily fixed to the substrate holder.

[0082] In this technology, it is preferable that the substrate holder has a holder-side contact surface formed thereon, which contacts the end face of the circuit board on the first press-fit fixing portion side of the circuit board, which is one end face of the circuit board in the axial direction of the rotor. With this configuration, it becomes possible to position the circuit board relative to the substrate holder on one side in the axial direction of the rotor. Furthermore, with this configuration, the temporary fixing of the circuit board to the substrate holder is completed by pushing the circuit board to one side in the axial direction of the rotor relative to the substrate holder until the end face of the circuit board contacts the holder-side contact surface. Therefore, the temporary fixing of the circuit board to the substrate holder can be easily performed. [Explanation of Symbols]

[0083] 2 motors 10 rotors 11 stata 12 Motor Case 13 Circuit board 13d Upper end surface (second substrate side restricting surface) 13f Bottom end surface (1st board side regulation surface) 14. PCB holder 14t press-fit fixing section (first press-fit fixing section) 14V press-fit fixing part (second press-fit fixing part) 14w Restricting surface (holder-side restricting surface, holder-side contact surface) 15 Cover 15e Board holding groove 15f Restriction surface (restriction surface on the cover side) 15g Upper end surface (cover side contact surface) 31 Connectors 32. Mating connector 33, 34 Electronic components Z rotor axial direction, mating connector insertion / removal direction Z1 First direction side, the other side of the insertion / removal direction of the mating connector Z2 Second direction side, one side of the insertion / removal direction of the mating connector

Claims

1. A motor comprising a rotor and a stator, a motor case housing the rotor and the stator, a power supply circuit board disposed outside the motor case, electronic components mounted on the circuit board, and a cover covering the electronic components.

2. The motor according to claim 1, characterized in that the circuit board is formed in the shape of a flat plate and arranged parallel to the axial direction of the rotor.

3. The motor case is equipped with a circuit board holder that holds the circuit board and to which the cover is attached, The motor according to claim 2, characterized in that the substrate holder holds one side of the circuit board in the axial direction of the rotor.

4. The aforementioned circuit board has a connector mounted on it. The connector is connected to and disconnected from the mating connector in the axial direction of the rotor. The cover has a cover-side restricting surface formed to restrict the movement of the circuit board to one side in the insertion / removal direction of the mating connector. The substrate holder is formed with a holder-side restricting surface for restricting the movement of the circuit board to the other side in the insertion / removal direction of the mating connector. The motor according to claim 3, characterized in that the circuit board has a first substrate-side restricting surface facing the cover-side restricting surface and a second substrate-side restricting surface facing the holder-side restricting surface.

5. If one side of the rotor in the axial direction is designated as the first direction side, and the other side of the rotor in the axial direction opposite to the first direction side is designated as the second direction side, The cover is attached to the substrate holder from the second direction side. The cover has substrate holding grooves formed therein for holding both ends of the circuit board in a direction perpendicular to the axial direction of the rotor and the thickness direction of the circuit board. The motor according to claim 3 or 4, characterized in that the substrate holding groove is open on the first direction side and is formed in a straight line parallel to the axial direction of the rotor.

6. If one side of the rotor in the axial direction is designated as the first direction side, and the other side of the rotor in the axial direction opposite to the first direction side is designated as the second direction side, The cover is attached to the substrate holder from the second direction side. The motor according to claim 3 or 4, characterized in that the cover has a cover-side contact surface that contacts the end face of the motor case on the second direction side.

7. The motor comprises a rotor and a stator, a motor case housing the rotor and the stator, a power supply circuit board located outside the motor case, and a circuit board holder attached to the motor case and holding the circuit board. The circuit board is formed in a flat plate shape, The motor is characterized in that the substrate holder has press-fit fixing portions formed therein that contact the circuit board with a predetermined contact pressure from both sides in the thickness direction of the circuit board.

8. The motor according to claim 7, characterized in that the circuit board is arranged parallel to the axial direction of the rotor.

9. The motor according to claim 8, characterized in that the substrate holder has a first press-fit fixing portion which holds one end of the circuit board in the axial direction of the rotor, and a second press-fit fixing portion which holds both ends of the circuit board in a direction perpendicular to the axial direction of the rotor and the thickness direction of the circuit board.

10. The motor according to claim 9, characterized in that the substrate holder has a holder-side contact surface formed thereon, which is one end face of the circuit board in the axial direction of the rotor, and which contacts the end face of the circuit board on the first press-fit fixing portion side.

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