Motor device

Abstract

The invention provides a motor device which suppresses the generation of burrs during assembly and does not require subsequent deburring operation and the like. The rotating shaft (32) includes: a cylindrical portion (33a) having an outer diameter constant in an axial direction of the rotating shaft; a tapered portion (33b) provided on one side of the cylindrical portion in the axial direction, the tapered portion (33b) having an outer diameter gradually decreasing as the tapered portion (33b) moves away from the cylindrical portion; and an arc-shaped connecting part (33c) provided between the cylindrical part and the tapered part, the arc-shaped connecting part connecting the outer peripheral surface of the cylindrical part and the outer peripheral surface of the tapered part with an arc surface when the rotating shaft is viewed from the outside in the radial direction, the retainer member (61) having: a cylindrical body part (61a) into which the cylindrical part is press-fitted; and a gap forming cylinder part (61b) which is provided on one side of the cylindrical body part in the axial direction, and which forms a gap (SP) with the arcuate connection part in the radial direction of the rotating shaft.

Description

TECHNICAL FIELD

[0001] The present application relates to a motor device having a rotating shaft and a fixing member fixed to the rotating shaft. BACKGROUND

[0002] For example, in Patent Literature 1, there is described a wiper motor including an armature shaft including a bearing member mounting portion and a guide small diameter portion having a smaller diameter than the bearing member mounting portion, and an inner race of a ball bearing is fixed to the bearing member mounting portion by press-fitting.

[0003] [Patent Literature]

[0004] [Patent Literature]

[0005] [Patent Literature 1] Japanese Patent Application Laid-Open No. 2014-185663 SUMMARY

[0006] [Problems to be Solved by the Invention]

[0007] In the technology described in Patent Literature 1, when the ball bearing is fixed to the bearing member mounting portion, the guide small diameter portion is inserted into the inner race of the ball bearing, and thereafter, the bearing member mounting portion is press-fitted via the step between the guide small diameter portion and the bearing member mounting portion.

[0008] Therefore, when the bearing member mounting portion of the armature shaft is inserted into the inner race of the ball bearing, the press-fitting load of the armature shaft is abruptly increased. Thus, there is a risk that a corner portion disposed between the bearing member mounting portion and the step is thinned, or an inner wall of the inner race is thinned to generate so-called "burrs".

[0009] An object of the present application is to provide a motor device capable of suppressing generation of burrs at the time of assembly without the need for a subsequent deburring operation or the like.

[0010] [Means of Solving the Problems]

[0011] In one embodiment of the motor device, there is provided a rotating shaft, and a fixing member fixed to the rotating shaft, in which the rotating shaft includes a straight cylinder portion having a constant outer diameter toward an axial direction of the rotating shaft, a tapered portion provided on one side of the axial direction of the straight cylinder portion and gradually decreasing in outer diameter as it moves away from the straight cylinder portion, and a connecting portion provided between the straight cylinder portion and the tapered portion, the connecting portion connecting an outer peripheral surface of the straight cylinder portion and an outer peripheral surface of the tapered portion with a circular arc surface when the rotating shaft is viewed from an outer radial direction, and the fixing member has a press-fitting cylinder portion for press-fitting the straight cylinder portion, and a gap forming cylinder portion provided on one side of the axial direction of the press-fitting cylinder portion and forming a gap between the connecting portion in the radial direction of the rotating shaft.

[0012] [Effects of Invention]

[0013] By the present application, a motor device capable of suppressing burr generation at the time of assembly without the need for a subsequent deburring operation or the like can be realized. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 is a perspective view of the motor device as viewed from the bracket side.

[0015] Figure 2 is a perspective view of the motor device as viewed from the housing side.

[0016] Figure 3 is a sectional view showing the internal structure of the motor device.

[0017] Figure 4 is a sectional view showing only the rotor of Figure 3

[0018] Figure 5 is a perspective view showing the rotating shaft as a single body.

[0019] Figure 6 is a perspective view of the magnet unit as viewed from the rotor main body side.

[0020] Figure 7 is a perspective view of the magnet unit as viewed from the pinion gear portion side.

[0021] Figure 8 is an enlarged sectional view showing the fixing structure of the magnet unit to the rotating shaft.

[0022] Figure 9 is an assembly explanatory view showing the [part mounting process].

[0023] Figure 10 is an assembly explanatory view showing the [rotating shaft moving process].

[0024] Figure 11 is an assembly explanatory view showing the [pressing-in process].

[0025] Figure 12 is a view showing the assembly state of the present embodiment.

[0026] Figure 13 is a view showing the comparative example corresponding to Figure 8

[0027] is a view showing the comparative example corresponding to Figure 14

[0028] is a view showing the modified example corresponding to Figure 15 Figure 8

[0029] BRIEF DESCRIPTION OF DRAWINGS​​​

[0030] 10: Motor unit

[0031] 20: Shell

[0032] 21: Cylindrical section

[0033] 22: Opening

[0034] 23: Bottom wall

[0035] 24: Flange portion

[0036] 25: Stator

[0037] 26: Stator core

[0038] 26a: Core body

[0039] 26b: teeth

[0040] 27: Insulator

[0041] 28: Coil

[0042] 29: Busbar Unit

[0043] 29a: Retaining member

[0044] 30: Conductive components

[0045] 31: Rotor

[0046] 32: Rotation axis

[0047] 32a: Large diameter part

[0048] 32b: Small diameter portion

[0049] 32c: Bearing support section

[0050] 32d: Pinion section

[0051] 33: Mid-diameter section

[0052] 33a: Cylindrical section (straight section)

[0053] 33b: Conical part

[0054] 33c: Arc-shaped connecting part (connecting part)

[0055] 34: Rotor body

[0056] 35: Rotor core

[0057] 36: Magnet

[0058] 37: Magnetic Cover

[0059] 38: Magnet protection components

[0060] 40: bracket

[0061] 41: partition wall portion

[0062] 41a: first terminal hole

[0063] 41b: second terminal hole

[0064] 42: insertion hole portion

[0065] 43: bearing holder

[0066] 43a: insertion hole

[0067] 44: annular fixing plate

[0068] 46: cylindrical wall portion

[0069] 47: drive object fixing portion

[0070] 48: housing fixing portion

[0071] 49: fitting cylindrical portion

[0072] 50: sensor substrate

[0073] 51: Hall element

[0074] 52: through hole

[0075] 60: magnet unit

[0076] 61: holder member (fixing member)

[0077] 61a: cylindrical main body portion (press-in cylindrical portion)

[0078] 61b: gap forming cylindrical portion

[0079] 61c: flange portion

[0080] 61d: outer peripheral front end portion

[0081] 62: annular magnet (sensor magnet)

[0082] 62a: inner peripheral recessed portion

[0083] AG: air gap

[0084] BR1: first bearing

[0085] BR2: second bearing

[0086] C: axis

[0087] CC: C chamfered portion (comparative example)

[0088] CD: conveyance device

[0089] CL: collar

[0090] CM: cylindrical main body portion (comparative example)

[0091] CN: connector connecting portion

[0092] CP1: first cover

[0093] CP2: second cover

[0094] CR: cylindrical portion (comparative example)

[0095] DS1: installation distance

[0096] DS2: distance before pressing in

[0097] DS3: distance after pressing in

[0098] ED: edge (comparative example)

[0099] F: pressing force

[0100] GD: gripping device

[0101] GT: gate mark

[0102] H1: first insertion hole

[0103] H2: second insertion hole

[0104] IT: internally threaded member

[0105] MN: unit holding member

[0106] MP: fitting portion

[0107] MU: magnet unit (comparative example)

[0108] PT: power supply terminal

[0109] S1: first externally threaded member

[0110] S2: second externally threaded member

[0111] SH: rotation shaft (comparative example)

[0112] SL: annular seal

[0113] SN: shaft holding member

[0114] SP: gap

[0115] SS: slight gap

[0116] ST: sensor terminal

[0117] TP: taper for installation guide

[0118] TR: tapered portion (comparative example) DETAILED DESCRIPTION

[0119] Hereinafter, an embodiment of the present application will be described in detail with reference to the drawings.

[0120] <MOTOR DEVICE>

[0121] Figure 1 is a perspective view of the motor device as viewed from the bracket side, Figure 2 is a perspective view of the motor device as viewed from the housing side, Figure 3 is a sectional view showing the internal structure of the motor device.

[0122] Figures 1 to 3 The motor device 10 shown is used, for example, as a drive source of an electric brake device of a vehicle such as an automobile. The motor device 10 is a brushless motor, and includes a housing 20 made of metal. The housing 20 is formed into a bottomed cylindrical shape by deep drawing processing or the like of a metal plate. The housing 20 includes a cylindrical portion 21, and an opening portion 22 is provided on the axial one side (upper side) of the cylindrical portion 21. On the other hand, a bottom wall portion 23 is provided on the axial other side (lower side) of the cylindrical portion 21. Figure 3 Figure 3

[0123] A plurality of flange portions 24 protruding to the radial direction outer side are provided on the opening portion 22 side of the cylindrical portion 21, and these flange portions 24 are fitted on the axial other side (lower side) of a bracket 40 made of resin by three first external screw members S1 in total. Further, a first through-hole H1 through which the first external screw member S1 is inserted and a second through-hole H2 through which a fixing bolt (not shown) for fixing the motor device 10 to a driven object (an electric brake device or the like) is inserted are provided in each of the flange portions 24. Figure 3

[0124] Thus, the opening portion 22 of the housing 20 made of metal is closed by the bracket 40 made of resin. Further, the first external screw members S1 are fastened by a screwdriver (not shown) with a front end side being positive (+).

[0125] <STATOR>

[0126] As shown in Figure 3 , a stator (fixed sub) 25 is housed in the inside of the housing 20. Specifically, the stator 25 is fixed to the radial direction inner side of the cylindrical portion 21 by press-fitting. The stator 25 includes a stator core 26 formed into a substantially cylindrical shape, and the stator core 26 is formed by laminating a plurality of thin steel plates. The stator core 26 includes a core main body 26a formed into a substantially cylindrical shape, and a plurality of teeth 26b protruding to the radial direction inner side of the core main body 26a.

[0127] ​​​Resin insulators 27 are mounted on each of the multiple teeth 26b. Coils 28, including U-phase, V-phase, and W-phase coils, are wound around the outside of the insulators 27 in a predetermined winding manner and number of windings. That is, three-phase coils 28 are wound on each of the multiple teeth 26b via the insulators 27, which function as insulators. Furthermore, the three-phase coils 28 are arranged alternately in the circumferential direction of the stator 25 in a manner that forms U-phase, V-phase, W-phase, etc.

[0128] On one axial side of stator 25 ( Figure 3 A ring-shaped busbar unit 29 is mounted on the upper side of the busbar. The busbar unit 29 includes multiple conductive members 30 corresponding to the U phase, V phase, and W phase, and these conductive members 30 are held by a ring-shaped retaining member 29a. In addition, the retaining member 29a contains an insulator such as plastic to prevent short circuits of the individual conductive members 30.

[0129] Furthermore, the end of the three-phase coil 28 is electrically connected to one end of each conductive member 30. On the other hand, the other end of each conductive member 30 is electrically connected to one end of the power supply terminal PT provided in the bracket 40.

[0130] Here, three power terminals PT are provided corresponding to the U phase, V phase, and W phase. The other end of these power terminals PT protrudes to the inside of the connector connection part CN for connection to the connector component (not shown) on the vehicle side.

[0131] <Rotor>

[0132] Figure 4 It only means Figure 3 A cross-sectional view of the rotor. Figure 5 It is a three-dimensional diagram that uses a single unit to represent the axis of rotation. Figure 6 This is a three-dimensional view of the magnet unit as seen from the rotor body side. Figure 7 This is a three-dimensional view of the magnet unit as seen from the side of the small gear section. Figure 8 This is an enlarged cross-sectional view showing the fixed structure in which the magnet unit is fixed to the rotation axis.

[0133] like Figure 3 and Figure 4 As shown, the motor assembly 10 includes a rotor (rotating body) 31 that rotates relative to the stator 25. The rotor 31 has a rotating shaft 32 and a rotor body 34.

[0134] <Rotation axis>

[0135] like Figure 4 and Figure 5As shown, the rotating shaft 32 is made of carburized, quenched, and tempered alloy steel for mechanical structures, such as "SNCM420", which has undergone heat treatment. The outer periphery of the round steel bar (raw material) is machined and ground to form a stepped shape. That is, the rotating shaft 32 is a machined / ground product with a hardness (Vickers hardness) of approximately "700Hv".

[0136] Specifically, the rotating shaft 32 includes a large-diameter portion 32a, a medium-diameter portion 33 with a diameter smaller than that of the large-diameter portion 32a, and a small-diameter portion 32b with a diameter smaller than that of the medium-diameter portion 33. Furthermore, as... Figure 3 As shown, the rotating shaft 32 is configured to pass through the through hole 52 provided on the sensor substrate 50 and traverse the bracket 40.

[0137] The large-diameter portion 32a is disposed on the other side of the axial direction of the rotating shaft 32. Figure 5 On the right side of the large-diameter portion 32a, the rotor core 35, which forms the rotor body 34, is fixed by pressing onto the outer periphery of the large-diameter portion 32a. Thus, the rotating shaft 32 rotates together with the rotor core 35. Furthermore, on the other axial side of the large-diameter portion 32a (… Figure 5 A bearing support 32c is provided on the right side of the bearing, wherein the bearing support 32c consists of a first bearing BR1 (refer to...). Figure 3 The support allows for free rotation.

[0138] In addition, the intermediate diameter portion 33 is disposed on one side of the axial direction of the large diameter portion 32a. Figure 5 (on the left side), its axial length is approximately 1 / 4 of the axial length of the large diameter portion 32a. Furthermore, a magnet unit 60 (see reference) is fixed to the outer periphery of the middle diameter portion 33. Figure 6 and Figure 7 Here, the magnet unit 60 is used to detect the rotational state of the rotor 31 (rotation shaft 32) and rotates together with the rotation shaft 32.

[0139] Furthermore, the small diameter portion 32b is disposed on one axial side of the intermediate diameter portion 33. Figure 5 (on the left side), its axial length is approximately 1.5 times the axial length of the intermediate diameter portion 33. Furthermore, the small diameter portion 32b is supported by a second bearing BR2 (see reference). Figure 3 The support allows for free rotation. In addition, the pair of first bearings BR1 and second bearings BR2 that support the axial sides of the rotating shaft 32 for free rotation are both ball bearings (details not shown).

[0140] Additionally, on the axial side of the small diameter portion 32b ( Figure 5On the left side, a pinion gear 32d, which forms the output section of the motor device 10, is integrally provided. Specifically, the pinion gear 32d is connected, for example, to a feed screw shaft (not shown) that moves the piston of the electric brake device forward and backward in a manner that enables power transmission.

[0141] <Middle Diameter>

[0142] like Figure 8 As shown, the middle diameter portion 33 to which the magnet unit 60 is fixed has a cylindrical portion 33a, a tapered portion 33b, and an arc-shaped connecting portion 33c. Specifically, the cylindrical portion 33a extends straight in a manner where its outer diameter is constant in the axial direction toward the rotation axis 32, and is the portion with the largest outer diameter among the middle diameter portions 33. Furthermore, a cylindrical main body portion 61a that forms the retainer member 61 of the magnet unit 60 is fixed to the cylindrical portion 33a by pressing.

[0143] Furthermore, the cylindrical portion 33a corresponds to the straight cylindrical portion in this invention.

[0144] In addition, the tapered portion 33b is provided on one axial side of the cylindrical portion 33a. Figure 8 (on the left side), and the outer diameter gradually decreases as it moves away from the cylindrical portion 33a. Specifically, the tapered portion 33b has a cross-sectional area on the axial side of the rotation axis 32 in a direction orthogonal to the axial direction of the rotation axis 32 (on the left side), and the outer diameter gradually decreases as it moves away from the cylindrical portion 33a. Figure 8 The cone shape gradually decreases in size from the left side. Furthermore, the magnet unit 60 is pressed into the cylindrical portion 33a from the axial side of the cone portion 33b (see reference). Figures 9 to 11 ).

[0145] Furthermore, the arc-shaped connecting portion 33c is disposed axially between the cylindrical portion 33a and the tapered portion 33b along the rotation shaft 32. Specifically, as... Figure 8 As shown, when viewing the rotation axis 32 from the outside in the radial direction, the outer periphery of the arc-shaped connecting portion 33c is formed into an arc shape with a radius dimension R. Here, the arc-shaped connecting portion 33c has the function of smoothly connecting the cylindrical portion 33a and the conical portion 33b to each other without any step difference in the axial direction of the rotation axis 32. That is, the arc-shaped connecting portion 33c connects the outer peripheral surface of the cylindrical portion 33a and the outer peripheral surface of the conical portion 33b with an arc surface. As a result, the magnet unit 60 can be easily pressed into the cylindrical portion 33a (see reference 33b) from the axial side of the conical portion 33b. Figures 9 to 11 ).

[0146] Furthermore, the arc-shaped connecting portion 33c corresponds to the connecting portion in this invention.

[0147] Here, on one side of the tapered portion 33b ( Figure 8 A small-diameter portion 32b is provided on the left side. Moreover, the outer diameter dimension D1 of the small-diameter portion 32b is smaller than the outer diameter dimension D2 on the axial side of the tapered portion 33b (D1 < D2).

[0148] Furthermore, the length L1 of the arc-shaped connecting portion 33c along the axial direction of the rotating shaft 32 is shorter than the length L2 of the tapered portion 33b along the axial direction of the rotating shaft 32 (L1 < L2). Moreover, the length L3 of the cylindrical portion 33a along the axial direction of the rotating shaft 32 is longer than the length L2 of the tapered portion 33b along the axial direction of the rotating shaft 32 (L3 > L2). In other words, if these lengths L1 to L3 are expressed in terms of size, it is "L1 < L2 < L3".

[0149] In addition, such as Figure 8 As shown, the entire axial region of the inner circumferential surface of the cylindrical main body 61a forming the retainer member 61 is in contact with the outer circumferential surface of the cylindrical portion 33a. That is, the inner circumferential surface (fitting portion MP) of the cylindrical main body 61a is disposed within the axial range of the cylindrical portion 33a. As a result, the fixing strength of the magnet unit 60 relative to the rotation axis 32 can be sufficiently ensured.

[0150] Furthermore, within the axial range of the cylindrical portion 61b forming the gap in the retainer member 61, the entire axial area where the arc-shaped connecting portion 33c is disposed and the other axial side of the tapered portion 33b are also included. Figure 8 (The right side) Part. In other words, in the radial direction of the rotation axis 32, the entire arc-shaped connecting portion 33c and a part of the tapered portion 33b overlap with the gap-forming cylindrical portion 61b of the retainer member 61.

[0151] Here, the cylindrical portion 33a is shaped by "cutting". In contrast, the tapered portion 33b and the arc-shaped connecting portion 33c are shaped by "grinding". That is, the outer peripheral surfaces of the tapered portion 33b and the arc-shaped connecting portion 33c are smoother than the outer peripheral surface of the cylindrical portion 33a. As a result, it is easy to press the rotating shaft 32 into the retainer member 61, and it is difficult to pull the retainer member 61 out of the rotating shaft 32.

[0152] <Rotor Body>

[0153] Furthermore, such as Figure 3 and Figure 4 As shown, the rotor body 34 fixed to the outer periphery of the large-diameter portion 32a includes a rotor core 35 formed into a generally cylindrical shape by stacking multiple thin steel plates (ferromagnetic materials) and a cylindrical magnet 36 mounted on the radially outer side of the rotor core 35. Furthermore, the radially outer side of the magnet 36 is covered by a cylindrical magnet cover 37 containing stainless steel plates or the like.

[0154] The magnet cover 37 is constructed by axially covering one side of the magnet cover 37 ( Figure 4The magnet 36 is fixed to the outer periphery of the rotor 36 by riveting it inward in the radial direction from the left side. This ensures that the rotation center of the magnet 36 is precisely aligned with the rotation center of the rotor core 35, thus suppressing rotational vibration of the rotor 31. Furthermore, it narrows the air gap AG between the rotor body 34 and the stator 25 (see reference). Figure 3 This enables the creation of a small and high-output (high-efficiency) motor device 10.

[0155] In addition, in order to suppress the riveting force of the magnet cover 37 from being transmitted to the magnet 36, a magnet protection member 38 containing a resin material such as plastic is provided on the other side of the axial direction of the magnet cover 37.

[0156] Here, the motor device 10 is not limited to the surface magnet type (surface permanent magnet) where a magnet 36 is mounted on the surface of the rotor core 35 as described above, but can also be the embedded magnet type (interior permanent magnet) where a magnet is embedded inside the rotor core.

[0157] <Bracket>

[0158] like Figure 1 and Figure 3 As shown, the bracket 40 has the function of fixing the motor device 10 to the object being driven. The bracket 40 is formed into a generally circular plate shape by injection molding of molten plastic or other resin material. That is, the bracket 40 is an injection-molded product.

[0159] The bracket 40 includes a partition wall 41 formed in a generally circular plate shape. The partition wall 41 axially separates the housing 20 side from the rotating shaft 32. Figure 3 (the lower side) and the driving object side ( Figure 3 The upper side) is separated, and at the center of the partition wall 41, an axial section for the rotating shaft 32 is integrally provided on the other side. Figure 3 The upper side of the insertion tube 42 is inserted through.

[0160] Furthermore, a bearing retainer 43, which is formed into a roughly cup shape by pressing a steel plate, is provided on the inner side of the insert cylinder portion 42 in the radial direction. Specifically, the outer side of the bearing retainer 43 in the radial direction is fixed to the inner side of the insert cylinder portion 42 in the radial direction.

[0161] Furthermore, the bearing retainer 43 is provided with an insertion hole 43a for the rotating shaft 32 to pass through, and the bearing retainer 43 holds the second bearing BR2 in a manner coaxial with the insertion sleeve portion 42. Additionally, on the other axial side of the second bearing BR2 ( Figure 3 On the lower side, an annular fixing plate 44 is provided to prevent the second bearing BR2 from falling off the bearing retainer 43.

[0162] Furthermore, on the other side of the axial direction of the insertion cylinder portion 42 ( Figure 1 A sensor substrate 50 is provided on the lower side of the partition wall 41. Specifically, the sensor substrate 50 is fixed to the housing 20 side of the partition wall 41 by a plurality of second external thread members S2.

[0163] In addition, such as Figure 2 As shown, a total of three power terminals PT are provided in the partition wall section 41 (refer to...). Figure 2 One end of the sensor is disposed in the first terminal hole 41a on the inner side, and a total of five sensor terminals ST (see reference). Figure 1 One end of the device is disposed in the second terminal hole 41b on the inner side. Furthermore, in order to cover the power terminal PT and the sensor terminal ST, a first cover CP1 and a second cover CP2 are respectively installed in the first terminal hole 41a and the second terminal hole 41b.

[0164] Furthermore, such as Figure 3 and Figure 3 As shown, a cylindrical wall portion 46 with a diameter larger than that of the insertion cylindrical portion 42 is provided on the outer side of the insertion cylindrical portion 42 in the radial direction. Specifically, the cylindrical wall portion 46 is disposed on the outer periphery of the partition wall portion 41.

[0165] The cylindrical wall portion 46 is coaxially positioned relative to the through-tube portion 42 and extends axially along the rotation shaft 32. Furthermore, a total of three drive object fixing portions 47 are integrally provided on the cylindrical wall portion 46. These drive object fixing portions 47 are provided with metal cylindrical collars CL. Therefore, the motor assembly 10 can be reliably fixed to the drive object without damaging the resin drive object fixing portions 47.

[0166] Furthermore, the drive object fixing parts 47 are arranged at predetermined intervals in the circumferential direction of the cylindrical wall part 46, and when the bracket 40 is viewed from the other side (the housing 20 side) in the axial direction, it protrudes outward in the radial direction of the cylindrical wall part 46. In addition, a fixing bolt for fixing the motor device 10 to the drive object is inserted into the collar CL that holds the drive object fixing parts 47.

[0167] Furthermore, a connector connection portion CN is integrally provided on the outer side of the cylindrical wall portion 46 in the radial direction. The connector connection portion CN is formed in a generally cuboid shape, allowing the connector member on the vehicle side to enter from the other side of the cylindrical wall portion 46 in the axial direction. Figure 3 (The lower side) is connected.

[0168] In addition, a total of three housing fixing parts 48 are integrally provided on the cylindrical wall portion 46. These housing fixing parts 48 are portions used to fix the flange portion 24 of the housing 20, and are respectively for the steel cylindrical internally threaded member IT (see reference). Figure 3Furthermore, each of these internally threaded members IT is screwed with a first externally threaded member S1 for securing the housing 20 to the bracket 40.

[0169] A total of three housing fixing parts 48 are arranged at predetermined intervals in the circumferential direction of the cylindrical wall portion 46, and the housing fixing parts 48 are disposed between adjacent drive object fixing parts 47. In addition, each housing fixing part 48 protrudes radially outward from the cylindrical wall portion 46 when the bracket 40 is viewed from the other side of the axial direction (the housing 20 side).

[0170] Furthermore, such as Figure 3 As shown, a fitting cylindrical portion 49 is integrally provided between the insertion cylindrical portion 42 and the cylindrical wall portion 46 on the other axial side (housing 20 side) of the bracket 40 and in the radial direction of the bracket 40.

[0171] The fitting cylindrical portion 49 is the part that fits into the opening 22 of the housing 20, and an annular seal SL containing an elastic material such as rubber is installed on its radially outer side. The annular seal SL seals the bracket 40 and the housing 20.

[0172] <Sensor substrate>

[0173] like Figure 2 As shown, the sensor substrate 50, fixed to the bracket 40, is arranged axially between the second bearing BR2 and the annular magnet 62 of the magnet unit 60 along the rotation shaft 32. Furthermore, a total of three Hall elements 51 are mounted on the sensor substrate 50 (only one is shown in the figure). Specifically, the three Hall elements 51 are provided corresponding to the U phase, V phase, and W phase, and are arranged around the through hole 52 provided in the central part of the sensor substrate 50.

[0174] Here, a total of three Hall elements 51 detect changes in the magnetic poles of the annular magnet 62 as the rotating shaft 32 rotates. That is, the Hall elements 51 detect the rotational state of the annular magnet 62. Additionally, a total of five sensor terminals ST are electrically connected to one end of the sensor substrate 50. Furthermore, the other ends of the five sensor terminals ST are exposed inside the connector connection portion CN for connection to the connector component on the vehicle side (see reference). Figure 3 and Figure 4 ).

[0175] <Magnetic Unit>

[0176] like Figures 6 to 8 , Figure 8 As shown, the magnet unit 60 includes a retainer member 61 and a ring magnet 62. The retainer member 61 is, for example, made of free-machining brass "C3604", and is formed into a flanged and stepped cylindrical shape by machining. That is, the retainer member 61 is a machined product with a hardness (Vickers hardness) of approximately "131Hv".

[0177] That is, the rotating shaft 32 into which the magnet unit 60 is fitted has a hardness (approximately 700 Hv) that is higher than the hardness (approximately 131 Hv) of the retainer member 61.

[0178] The retainer member 61 includes a cylindrical body portion 61a. The cylindrical body portion 61a extends axially toward the other side of the annular magnet 62. Figure 11 It is provided in a way that protrudes from the right side and extends axially along the rotation axis 32. Moreover, the cylindrical main body 61a is fixed to the cylindrical part 33a of the middle diameter part 33 by pressing, and its axial length is LG1.

[0179] Furthermore, the inner diameter D3 of the cylindrical main body 61a is slightly larger than the outer diameter of the cylindrical part 33a. Therefore, the cylindrical main body 61a can apply a specified pressing force F (refer to...) Figure 8 It is pressed into the cylindrical part 33a. Here, the axial length LG1 of the cylindrical main body part 61a is smaller than the length dimension L3 of the cylindrical part 33a (LG1 < L3).

[0180] Additionally, on the other side of the axial direction of the cylindrical main body 61a ( Figure 9 At the right end of the cylindrical body 61a, a tapered surface TP for guiding the insertion of the rotating shaft 32 is provided. Specifically, the tapered surface TP is formed such that it is located inside the cylindrical body 61a in the radial direction, and the opening area of ​​the cylindrical body 61a gradually increases towards the other side of the axial direction of the cylindrical body 61a. Moreover, the tapered surface TP is positioned relative to the axis C of the rotating shaft 32 (see reference φ). Figure 8 The acute angle of α is approximately 20 degrees and less than 45 degrees.

[0181] Therefore, the axis C of the rotation shaft 32 inserted into the cylindrical body 61a can be easily aligned with the center of the cylindrical body 61a (centering is possible). That is, the tapered surface TP for installation guidance has the function of guiding the cylindrical part 33a to be installed into the cylindrical body 61a.

[0182] Here, if the angle between the tapered surface TP used for mounting guidance and the acute angle side of the axis C of the rotating shaft 32 is increased (for example, greater than 45 degrees), the rotating shaft 32 will easily get caught on the tapered surface TP. This results in a decrease in the assembly workability of the motor assembly 10. Therefore, in this embodiment, the angle of the tapered surface TP is set to α degrees (approximately 20 degrees), making it less likely for the rotating shaft 32 to get caught on the cylindrical main body 61a, allowing for rapid centering of both (improved assembly workability).

[0183] Furthermore, the retainer component 61 corresponds to the fixing part in the present invention, and the cylindrical main body 61a corresponds to the press-in cylinder part in the present invention.

[0184] Additionally, the retainer member 61 includes a gap-forming cylindrical portion 61b. Specifically, the gap-forming cylindrical portion 61b is arranged side-by-side on one axial side of the cylindrical main body portion 61a. Figure 8 The gap forming cylindrical portion 61b overlaps with a portion of the tapered portion 33b and the entire arc-shaped connecting portion 33c in the radial direction of the rotation axis 32. Furthermore, the inner diameter D4 of the gap forming cylindrical portion 61b is larger than the inner diameter D3 of the cylindrical main body portion 61a (D4 > D3). Therefore, an annular gap SP is formed between the gap forming cylindrical portion 61b, the tapered portion 33b, and the arc-shaped connecting portion 33c in the radial direction of the rotation axis 32.

[0185] Here, by providing an annular gap SP inside the radial direction of the gap-forming cylindrical portion 61b, even if "burrs (chips)" are generated when the rotating shaft 32 is pressed into the retainer member 61, the burrs are small and can remain in the annular gap SP. Furthermore, by providing the annular gap SP, strain transmission to the flange portion 61c that holds the annular magnet 62 can be suppressed when the rotating shaft 32 is pressed into the cylindrical body portion 61a. Therefore, the annular magnet 62 will not experience strain.

[0186] On the axial side of the gap forming cylinder 61b ( Figure 6 A flange portion 61c is integrally provided on the left side and radially outward. The flange portion 61c protrudes radially outward from the gap forming cylinder portion 61b and is formed in a generally circular plate shape. Furthermore, the outer peripheral front end portion 61d of the flange portion 61c enters into the inner peripheral recess 62a of the annular magnet 62. In addition, during the injection molding of the annular magnet 62, the retainer member 61 and the annular magnet 62 are integrated.

[0187] Specifically, the ring magnet 62 is a so-called plastic magnet, made by mixing plastic with magnet raw materials, and is formed into a generally ring shape by injection molding using a mold. Thus, the ring magnet 62 is an injection-molded product, and as... Figure 9 As shown, a pair of gate marks GT are formed on the annular magnet 62.

[0188] Thus, the retainer member 61 holds the annular magnet 62 used to detect the rotational state of the rotating shaft 32. Furthermore, the annular magnet 62 corresponds to the sensor magnet in this invention.

[0189] Assembly Process

[0190] Next, the installation process (assembly process) of the magnet unit 60 relative to the rotation axis 32 will be described in detail using the accompanying drawings.

[0191] Figure 10 This is an assembly diagram showing the [parts installation process]. Figure 11 This is an assembly diagram illustrating the [rotary axis movement process].Figure 9 This is an assembly diagram illustrating the [pressing process].

[0192] <Parts Installation Procedure>

[0193] First, such as Figure 9 As shown, the rotating shaft 32 and the magnet unit 60 are to be manufactured in different manufacturing processes.

[0194] Next, the rotating shaft 32 is mounted on the conveying device CD. Specifically, as shown by arrow M1, the conveying device CD has a pair of shaft holding members SN that hold the rotating shaft 32 from both axial sides. These shaft holding members SN are movable along the axial direction of the rotating shaft 32 while holding it. That is, the conveying device CD has the function of conveying the rotating shaft 32 along its axial direction.

[0195] Furthermore, the magnet unit 60 is mounted on the gripping device GD. Specifically, as indicated by arrow M2, the gripping device GD has a pair of unit holding members MN, which hold the magnet unit 60 from its radial direction outward in a direction orthogonal to the axial direction of the rotation axis 32. Moreover, the pair of unit holding members MN have the function of positioning the magnet unit 60 on the axis C of the rotation axis 32 while holding it. Furthermore, the pair of unit holding members MN cannot move along the axial direction of the rotation axis 32.

[0196] Moreover, such as Figure 9 As shown, in the standby state, with the rotating shaft 32 mounted on the conveying device CD and the magnet unit 60 mounted on the holding device GD, the distance between the end of the rotating shaft 32 on the other side of the axial direction and the end of the holding device GD on the other side of the axial direction is the mounting distance DS1. Therefore, each component (rotating shaft 32 and magnet unit 60) can be easily mounted individually.

[0197] Thus, the [parts installation process] is completed. Afterwards, the conveying device CD is driven, and the feed speed is set to V1 (10 mm / s), causing the rotating shaft 32 to move towards the magnet unit 60.

[0198] <Rotary axis movement process>

[0199] Here, as Figure 10 As shown, with the rotating shaft 32 facing the magnet unit 60, before pressing the cylindrical portion 33a of the intermediate diameter portion 33 into the cylindrical main body portion 61a of the retainer member 61, the rotating shaft 32 is moved at a relatively fast feed speed V1 (10 mm / s). Then, as... Figure 10As shown, when the distance between the end of the rotating shaft 32 on the other side of the axial direction and the end of the gripping device GD on the other side of the axial direction is the pre-pressing distance DS2 (DS2 < DS1), the conveying device CD automatically sets the feed speed to V2 (1 mm / s).

[0200] Specifically, such as Figure 11 As shown, when the cylindrical main body 61a is positioned near the middle diameter 33 of the small diameter portion 32b of the rotating shaft 32, the feed speed V2 is reduced to 1 / 10 of the feed speed V1. This allows the rotating shaft 32 to move rapidly to the stage before being pressed into the cylindrical main body 61a.

[0201] This completes the [rotary axis movement process]. Afterwards, it is transferred to... Figure 11 The [pressing process].

[0202] <Pressing process>

[0203] like Figure 8 As shown, in order to press the cylindrical portion 33a into the cylindrical main body portion 61a at a constant feed speed V2 (1 mm / s), the conveying device CD is driven in a manner that generates a relatively large pressing force F. Therefore, the cylindrical main body portion 61a is connected via the tapered portion 33b of the middle diameter portion 33 and the arc-shaped connecting portion 33c (see reference). Figure 8 It fits into the cylindrical portion 33a of the middle diameter portion 33. At this time, the middle diameter portion 33 is guided by the tapered surface TP of the cylindrical main body portion 61a (see reference). Figure 12 Guided by the tube, it smoothly fits into the cylindrical main body 61a.

[0204] Subsequently, when the distance between the end of the rotating shaft 32 on the other side of the axial direction and the end of the gripping device GD on the other side of the axial direction is the pressing completion distance DS3 (DS3 < DS2), the conveying device CD automatically stops.

[0205] Therefore, the magnet unit 60 is positioned at a predetermined position in its axial direction relative to the rotation shaft 32. Thus, the [pressing process] is completed, and the fixing operation of the magnet unit 60 relative to the rotation shaft 32 is finished.

[0206] <Comparative Verification of Burr Generation>

[0207] Figure 13 This diagram illustrates the assembly state of this embodiment. Figure 8 It indicates a comparison example. Figure 14 The corresponding diagram, Figure 12 This is a diagram illustrating the assembly state of the comparative example. Furthermore, Figure 14 and Figure 12 The enlarged photograph of the upper section is a view of the pressing part (fitting part) of the rotating shaft and the magnet unit from the axial side.

[0208] like Figure 12 As shown in the enlarged photograph above, no so-called "burrs (chips)" are observed in the rotating shaft 32 and magnet unit 60 of this embodiment. That is, it can be confirmed that the assembly state of this embodiment is good and no subsequent deburring operation is required.

[0209] The reason is as follows: Figure 8 As shown in the lower section of the curve diagram, from the middle diameter portion 33 relative to the cylindrical main body portion 61a (refer to...) Figure 8 From the "pressing start" of the rotation shaft 32 relative to the magnet unit 60, as the stroke [mm] increases, the load [kN] increases relatively slowly, as shown by the dashed arrow. Specifically, the arc-shaped connecting portion 33c (see reference) provided by grinding on the rotation shaft 32... Figure 13 Due to the effect of ), the inner periphery of the cylindrical main body 61a is not thinned, but the cylindrical main body 61a is deformed in a way that gradually expands in diameter.

[0210] Even if some burrs are generated, they are small and remain in the gap of the retainer member 61, forming an annular gap SP between the cylindrical portion 61b and the middle diameter portion 33 of the rotating shaft 32. Therefore, no subsequent deburring operation is required.

[0211] Furthermore, as a comparative example, a structure similar to the previous fixed structure was prepared, and the generation of burrs was observed. Here, as... Figure 13 As shown, the comparative example's rotating shaft SH (Vickers hardness: 700 Hv) has a tapered portion TR and a cylindrical portion CR, but in the axial direction of the rotating shaft SH, there is no arc-shaped connection between the tapered portion TR and the cylindrical portion CR; instead, there is an edge ED. Furthermore, on the other side of the axial direction of the cylindrical body portion CM (Vickers hardness: 131 Hv) of the magnet unit MU... Figure 14 The right side is provided with a ring-shaped C-shaped chamfer CC that is β degree (45 degrees).

[0212] like Figure 14 As shown in the enlarged photograph above, in the comparative example, several relatively large burrs were produced to a visually perceptible degree. That is, in the comparative example, it was determined that subsequent deburring operations were required.

[0213] The reason is that, for example Figure 15 As shown in the lower section of the graph, the edge ED of the rotating shaft SH strongly abuts against the inner circumference of the cylindrical body CM, and as the stroke [mm] of the rotating shaft SH relative to the magnet unit MU increases, as indicated by the dashed arrow, the load [kN] increases sharply. As a result, the inner circumference of the cylindrical body CM is thinned by the edge ED, thereby producing relatively large burrs.

[0214] Furthermore, compared to the tapered surface TP (α degree = approximately 20 degrees) for mounting guidance in this embodiment, the annular C-shaped chamfer CC with a β degree (45 degrees) located on the other side of the axial direction of the cylindrical main body CM has a poor centering function for the rotating shaft SH. Therefore, the edge ED hooks onto the C-shaped chamfer CC, which also contributes to the generation of burrs.

[0215] <Variation Example>

[0216] In addition, the fixing structure of the magnet unit 60 relative to the rotation axis 32 can also be as follows: Figure 15 As shown in the variant example.

[0217] Figure 8 It represents the variation example and Figure 8 The corresponding diagram. The following only pertains to... Figure 8 The different parts will be explained. Furthermore, those with... Figure 15 Parts with the same function are marked with the same symbol, and their detailed descriptions are omitted.

[0218] like Figure 8 As shown, in the modified example, the length dimension L4 of the tapered portion 33b forming the middle diameter portion 33 is made larger than that of the tapered portion 33b forming the middle diameter portion 33. Figure 8 The tapered portion 33b shown has a longer length L2 (L4 > L2), and the cylindrical portion 33a has a longer length L5 than the tapered portion 33b. Figure 8 The length dimension L3 of the cylindrical part 33a shown is shorter (L5 < L3).

[0219] Furthermore, the axial length LG2 of the cylindrical main body 61a forming the retainer member 61 is greater than that of the other two parts. Figure 15 The cylindrical main body 61a shown has an axial length LG1 (LG2 > LG1), and the cylindrical main body 61a faces a portion of the cylindrical part 33a and the arc-shaped connecting part 33c in the radial direction of the rotation axis 32.

[0220] Therefore, as Figure 8 As shown in the enlarged view (dotted circle), a small gap SS is formed between the cylindrical main body 61a and the arc-shaped connecting portion 33c in the radial direction of the rotation axis 32. Furthermore, the fitting portion MP of the cylindrical main body 61a and the cylindrical portion 33a becomes a joint with the cylindrical main body 61a by extending the axial length LG2 of the cylindrical main body 61a. Figure 8 Equal. That is, regarding the fixing strength of the magnet unit 60 relative to the rotation axis 32, Figure 15 The implementation methods shown are as follows: Figure 15 The variations shown are all the same.

[0221] Here, in Figure 8In the modified example shown, with the magnet unit 60 fixed at a predetermined position on the rotation shaft 32, a small gap SS is formed between the cylindrical main body 61a and the arc-shaped connecting portion 33c. Therefore, even if the inner periphery of the cylindrical main body 61a is thinned to produce burrs, it is not necessary to cut the burrs away from the inner periphery of the cylindrical main body 61a. That is, the burrs can remain connected to the inner periphery of the cylindrical main body 61a.

[0222] Therefore, with ​ Compared to the embodiment shown, the generated burrs can be more reliably retained in the annular gap SP between the gap forming cylinder portion 61b and the middle diameter portion 33.

[0223] As detailed above, according to this embodiment, the rotating shaft 32 includes: a cylindrical portion 33a with a constant outer diameter axially toward the rotating shaft 32; a tapered portion 33b disposed on one axial side of the cylindrical portion 33a, with its outer diameter decreasing as it moves away from the cylindrical portion 33a; and an arc-shaped connecting portion 33c disposed between the cylindrical portion 33a and the tapered portion 33b. When the rotating shaft 32 is viewed from the outside in the radial direction, the arc-shaped connecting portion 33c connects the outer peripheral surface of the cylindrical portion 33a and the outer peripheral surface of the tapered portion 33b with an arc surface. The retainer member 61 has: a cylindrical main body portion 61a into which the cylindrical portion 33a is pressed; and a gap-forming cylindrical portion 61b disposed on one axial side of the cylindrical main body portion 61a, forming a gap SP between it and the arc-shaped connecting portion 33c in the radial direction of the rotating shaft 32.

[0224] Therefore, when the cylindrical portion 33a is pressed into the cylindrical main body portion 61a, the load can be gradually increased as the stroke of the rotating shaft 32 relative to the magnet unit 60 increases through the action of the arc-shaped connecting portion 33c. This suppresses the generation of burrs (chips), simplifying the manufacturing process by eliminating the need for subsequent deburring operations. Even if burrs are generated, they can remain in the gap forming the gap SP between the cylindrical portion 61b and the intermediate diameter portion 33, eliminating the need for subsequent deburring operations.

[0225] Furthermore, according to this embodiment, the rotating shaft 32 has a higher hardness than the retainer member 61, so even if burrs are generated, the rotating shaft 32 will not be thinned, while the retainer member 61 will be thinned. Therefore, the disruption of the rotational balance of the rotating shaft 32 can be minimized. In addition, even if burrs are generated, since the retainer member 61 is thinned, the burrs can be reliably induced into the gap SP.

[0226] Furthermore, according to this embodiment, a mounting guide tapered surface TP is provided at the axial end of the cylindrical main body 61a to guide the cylindrical portion 33a to be mounted onto the cylindrical main body 61a, thus enabling the cylindrical portion 33a to be smoothly mounted onto the cylindrical main body 61a. Therefore, the generation of burrs can be further suppressed.

[0227] Furthermore, according to this embodiment, the angle between the tapered surface TP for mounting guidance and the acute angle side of the axis C of the rotating shaft 32 is approximately 20 degrees and less than 45 degrees (α degrees). Therefore, the axis C of the rotating shaft 32 can be easily aligned (centered) with the center of the cylindrical main body 61a without scraping each other. Thus, the two can be assembled without hooks, which further suppresses the generation of burrs.

[0228] Furthermore, according to this embodiment, the fixing part fixed to the rotation shaft 32 is a retainer member 61 that holds the annular magnet 62 used to detect the rotational state of the rotation shaft 32, which can suppress the generation of burrs on the retainer member 61. Therefore, the fixing strength of the retainer member 61 (annular magnet 62) relative to the rotation shaft 32 can be sufficiently ensured, and the axes of the two can be aligned with good accuracy. Therefore, the sensing accuracy can be improved.

[0229] Furthermore, according to this embodiment, deburring as a subsequent process is unnecessary, thus enabling energy-saving manufacturing of the motor unit 10. This achieves, in particular, Goal 7 (ensuring access to affordable and reliable sustainable modern energy for all) and Goal 13 (taking urgent measures to mitigate climate change and its effects) of the United Nations Sustainable Development Goals (SDGs).

[0230] This invention is not limited to the described embodiments, and various modifications can be made without departing from its spirit. For example, in the described embodiment, the motor device 10 is shown as a drive source for an electric braking device mounted in a vehicle such as an automobile, but the invention is not limited thereto and can also be applied to drive sources for other vehicle-mounted devices (such as drive sources for electric power steering systems).

[0231] Furthermore, the material, shape, size, quantity, and location of each component in the embodiments are arbitrary as long as they achieve the present invention, and are not limited to the embodiments described.

Claims

1. A motor device comprising: Rotation axis; as well as A fixed component is attached to the rotating shaft within the motor assembly. The rotating shaft includes: The outer diameter of the straight cylindrical section is axially constant towards the axis of rotation; A tapered portion is provided on one axial side of the straight cylindrical portion, and its outer diameter gradually decreases as it moves away from the straight cylindrical portion; and A connecting portion is disposed between the straight cylindrical portion and the tapered portion. The connecting part When the rotation axis is viewed from the outside in the radial direction, the outer peripheral surface of the straight cylindrical portion and the outer peripheral surface of the tapered portion are connected by an arc surface. The fixing part has: The pressing-in cylindrical section is used to press the straight cylindrical section in; and A gap-forming cylindrical portion is provided on one axial side of the press-in cylindrical portion, forming a gap with the connecting portion in the radial direction of the rotation axis.

2. The motor device according to claim 1, wherein, The rotating shaft has a higher hardness than the fixed part.

3. The motor device according to claim 1, wherein, At the axial end of the press-in cylinder, there is a tapered surface for guiding the straight cylinder to be installed into the press-in cylinder.

4. The motor device according to claim 3, wherein, The angle of the tapered surface used for installation guidance relative to the acute angle side of the axis of rotation is less than 45 degrees.

5. The motor device according to any one of claims 1 to 4, wherein, The fixing part is a retainer component that holds the sensor magnet used to detect the rotational state of the rotating shaft.

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