JP7719692B2 - Motor - Google Patents

Description

The present invention relates to a motor.

A conventional motor includes a rotor, a stator, a case (motor housing), and a terminal block. The case houses the rotor and stator. The stator has a coil, and the power line terminals (conductors) connected to the coil are drawn radially outward from the housing. The terminal block is located radially outward from the case and has a fixing portion (connecting portion) that connects the power line terminals to external connection terminals (external terminals) (see, for example, Patent Document 1).

Japanese Patent Application Laid-Open No. 2008-125170

However, in conventional motors, the terminal block is located radially outside the housing, which can result in the motor becoming larger in the radial direction.

Therefore, the present invention aims to provide a motor that can be made smaller.

An exemplary motor of the present invention comprises a rotor, a stator, a bearing, a housing, and a terminal block. The rotor rotates around a rotation axis. The stator faces the rotor in the radial direction with a gap therebetween and has a conductor that forms a coil. The bearing rotatably supports the rotor. The housing accommodates the rotor, stator, and bearing. The terminal block is disposed on one axial side of the housing and is formed in a plate shape with at least a portion of the terminal block overlapping the bearing in the axial direction. The terminal block has a connection portion that connects the conductor to an external terminal. The conductor has a bent portion. The bent portion is drawn from the coil to one axial side and bent toward the connection portion in a direction perpendicular to the axial direction. The connection portion and the bent portion are disposed on opposite sides of a center line that extends radially through the rotation axis when viewed in the axial direction.

An exemplary embodiment of the present invention provides a motor that can be miniaturized.

FIG. 1 is a vertical cross-sectional perspective view of a motor according to an embodiment of the present invention. FIG. 2 is a perspective view of a motor according to an embodiment of the present invention. FIG. 3 is a perspective view of a motor according to an embodiment of the present invention. FIG. 4 is a perspective view of a motor according to an embodiment of the present invention. FIG. 5 is a perspective view of a terminal block of a motor according to an embodiment of the present invention. FIG. 6 is a perspective view of a terminal block of a motor according to an embodiment of the present invention.

An exemplary embodiment of the present invention will now be described in detail with reference to the drawings. The direction in which the central axis C of the motor 1 shown in FIG. 1 extends will be referred to simply as the "axial direction," and the radial and circumferential directions about the central axis C of the motor 1 will be referred to simply as the "radial direction" and "circumferential direction." The terms "axial direction," "radial direction," and "circumferential direction" are used merely for explanatory purposes and do not limit the actual positional relationship or direction. For convenience of explanation, this embodiment will describe the shape and positional relationship of each part, assuming that the axial direction is the up-down direction and the up-down direction in FIG. 1 is the up-down direction of the motor 1. For example, one axial side will be referred to as the axial upper side, or upper side. The other axial side will be referred to as the axial lower side, or lower side. However, these definitions of the up-down direction are not intended to limit the orientation of the motor 1 of the present invention during use.

<1. Motor configuration>
A motor according to an exemplary embodiment of the present invention will now be described. Fig. 1 is a vertical perspective view of a motor 1 according to an embodiment of the present invention.

The motor 1 includes a rotor 20, a stator 30, an upper bearing (bearing) 41, a lower bearing 42, a housing 50, a terminal block 60, and a rotation detector 92.

<2-1. Housing Configuration>

The housing 50 accommodates the rotor 20, the stator 30, the upper bearing 41, and the lower bearing 42. The housing 50 has a peripheral wall portion 51, a bottom wall portion 52, and an upper wall portion (lid wall portion) 53.

The peripheral wall portion 51 is formed in a cylindrical shape and extends in the axial direction. The upper and lower surfaces of the peripheral wall portion 51 are open. The lower surface of the peripheral wall portion 51 is covered by the bottom wall portion 52. The upper surface of the peripheral wall portion 51 is covered by the upper wall portion 53. In other words, the upper wall portion (lid wall portion) 53 covers the upper surface of the peripheral wall portion (one end surface in the axial direction).

The bottom wall portion 52 has a lower bearing holder 52a. The lower bearing holder 52a is formed in a cylindrical shape that surrounds the central axis C. The lower bearing 42 is housed and held in the lower bearing holder 52a.

The upper wall portion 53 has an upper bearing holder 53a, an upper wall through-hole (lid wall through-hole) 53b, an upper wall screw hole 53c, a side wall portion 53d, and an upper cylindrical portion 53e. The upper bearing holder 53a is formed in a cylindrical shape surrounding the central axis C. The upper bearing 41 is housed and held in the upper bearing holder 53a.

The upper wall through-hole 53b is located radially outward of the upper bearing holder 53a and penetrates the upper wall 53 in the axial direction. The conductor 33a, described below, is inserted through the upper wall through-hole 53b. Four upper wall screw holes 53c are provided around the upper bearing holder 53a (see Figure 3). A terminal block 60 is screwed to the upper surface of the upper wall 53 via the upper wall screw holes 53c.

The side wall portion 53d is cylindrical and protrudes axially upward from the upper surface of the upper wall portion 53. The side wall portion 53d surrounds the terminal block 60. The upper surface of the side wall portion 53d is open and covered by a cover 54. The side wall portion 53d has three side wall through holes 53f arranged in a row (see Figures 2 and 4). The side wall through holes 53f penetrate the side wall portion 53d radially. The external terminals 90 are drawn into the interior of the side wall portion 53d through the side wall through holes 53f.

The side wall portion 53d is also provided with one side wall through-hole 53g (see Figures 2 and 3). The side wall through-hole 53g penetrates the side wall portion 53d in the radial direction. A bundled signal line 73 (described later) is pulled out to the outside of the housing 50 through the side wall through-hole 53g.

The upper cylindrical portion 53e is cylindrical, surrounding the central axis C and extending axially upward from the upper surface of the upper wall portion 53. The rotation detector 92, described below, is located inside the upper cylindrical portion 53e. The upper cylindrical portion 53e and the upper bearing holder 53a are in axial communication.

<3. Rotor configuration>
The rotor 20 includes a shaft 21, a rotor core 22, and a rotor magnet 23. The shaft 21 forms a rotation axis extending along a central axis C and is formed in a columnar shape. That is, the rotor 20 has the shaft 21 extending along the rotation axis. The shaft 21 is supported by an upper bearing 41 and a lower bearing 42 so as to be rotatable about the axis.

The lower end of the shaft 21 protrudes outside the bottom wall portion 52 via the lower bearing holder 52a. The upper end of the shaft 21 is positioned inside the upper cylindrical portion 53e.

The rotor core 22 is cylindrical, and the shaft 21 is fixed inside by press-fitting. The rotor magnets 23 are provided on the radial outer surface of the rotor core 22, and multiple magnets 23 are arranged circumferentially. The rotor core 22 and rotor magnets 23 rotate integrally with the shaft 21.

4. Stator Configuration
The stator 30 is disposed radially outside the rotor 20. That is, the stator 30 faces the rotor 20 with a radial gap therebetween. The stator 30 is formed in a cylindrical shape, and the rotor 20 is disposed inside the stator 30. The stator 30 includes a core back portion 31, teeth portions 32, coils 33, and an insulating member (not shown).

The core back portion 31 is cylindrical and concentric with the shaft 21. The outer peripheral surface of the core back portion 31, i.e., the outer peripheral surface of the stator 30, is fitted into the inner peripheral surface of the peripheral wall portion 51 of the housing 50. In other words, the peripheral wall portion 51 is formed in a cylindrical shape and radially surrounds the stator 30.

The teeth 32 extend radially inward from the inner circumferential surface of the core back portion 31. Multiple teeth 32 are provided and are arranged at equal intervals around the circumferential surface of the core back portion 31.

The coils 33 are constructed by winding a conductor 33a around an insulating member (not shown). The coils 33 correspond to multiple phases, namely, U-phase, V-phase, and W-phase. In other words, the stator 30 has coils 33 for multiple phases. An insulating member is attached to each tooth portion 32. The ends of the conductor 33a wound around each tooth portion 32 extend axially upward and are pulled out axially upward of the upper wall portion 53 through each upper wall through-hole 53b, and are connected to the connection portion 61 of the terminal block 60. The connection structure of the conductor 33a will be described in detail later.

When a drive current is supplied to the coil 33, a magnetic field is generated, which causes the rotor 20 to rotate.

<5. Sensor magnet configuration>
The sensor magnet 91 is an annular permanent magnet with north and south poles arranged alternately in the circumferential direction. The sensor magnet 91 is fitted onto the upper end of the shaft 21. This allows the sensor magnet 91 to rotate together with the shaft 21.

<6. Rotation detector configuration>

In this embodiment, the rotation detector 92 is fixed inside the upper cylindrical portion 53e. The rotation detector 92 faces the sensor magnet 91 in the axial direction with a gap between them. The rotation detector 92 detects the magnetic flux of the sensor magnet 91 to detect the rotational position of the rotor 20. This outputs a motor drive signal corresponding to the rotational position of the rotor 20, controlling the drive current supplied to the coil 33. This allows the drive of the motor 1 to be controlled.

<7. Terminal block configuration>
The terminal block 60 is a plate-shaped resin molded product that is disposed on the upper surface (one axial end surface) of the upper wall portion (lid wall portion) 53 and fixed to the housing 50. The conductor wires 33a and external terminals 90 are fixed to the terminal block 60. The terminal block 60 is disposed axially above (on one axial side of) the housing 50, and at least a portion of the terminal block 60 axially overlaps the upper bearing 41 (bearing). This prevents the conductor wires 33a from being routed radially outward from the housing 50, enabling the motor 1 to be made smaller in the radial direction.

8. Connection structure between conducting wire and external terminal
2 to 4 are perspective views of the motor 1, and do not show the cover 54. Also, Fig. 2 shows the external terminal 90 with a dashed line. Fig. 3 does not show the terminal block 60 and the conductor 33a. Fig. 4 shows the connecting screw 61a in an exploded view.

The ends of the conductors 33a corresponding to the U-, V-, and W-phase coils 33 extend axially upward from the coils 33 and are pulled out axially upward of the upper wall portion 53 through the upper wall through-holes 53b. The conductors 33a also bend radially and extend along the upper surface of the terminal block 60. The conductors 33a are covered with an insulating member axially above the coils 33.

The conductor 33a has a connection terminal 33c located at its tip (see Figure 4). The connection terminal 33c has a terminal through-hole 33d. The terminal through-hole 33d is axially aligned with a terminal block screw hole 61b (see Figure 5) provided in the terminal block 60 and is screwed in place using a connection screw 61a. At this time, one end of the external terminal 90 is clamped between the connection screw 61a and the connection terminal 33c. This secures the conductor 33a and external terminal 90 to the terminal block 60. Therefore, the conductor 33a and external terminal 90 are electrically connected, and a motor drive signal is output from the external terminal 90 to the conductor 33a.

In this case, the terminal block screw hole 61b forms the connection portion 61 of the terminal block 60. In other words, the terminal block 60 has the connection portion 61 that connects the conductor 33a to the external terminal 90. The conductor 33a is pulled out axially upward (to one axial side) from the coil 33 and has a bent portion 33b that bends in a direction perpendicular to the axial direction toward the connection portion 61.

When viewed in the axial direction, the connection portion 61 and the bent portion 33b are positioned on opposite sides of the center line L, which extends radially through the rotation axis C (see Figure 2). This allows the connection portion 61 and the bent portion 33b to be positioned apart on the terminal block 60, allowing the length of the conductor 33a from the bent portion 33b to the connection portion 61 to be increased. This makes it easier to handle the conductor 33a when connecting it to the external terminal 90. This improves the ease of assembly of the motor 1. Furthermore, during assembly of the motor 1, the load on the bent portion 33b is reduced, preventing damage to the conductor 33a.

Furthermore, the multiple phase conductors 33a extend linearly and parallel from the bent portions 33b toward the connection portions 61 on the terminal block 60. This makes it easier to handle the multiple conductors 33a when connecting the conductors 33a to the external terminals 90. It also prevents the conductors 33a from crossing each other and becoming damaged on the terminal block 60.

<9. Terminal block configuration>
5 and 6 are perspective views of the terminal block 60. Fig. 5 shows the terminal block 60 from above in the axial direction, and Fig. 6 shows the terminal block 60 from below in the axial direction. The terminal block 60 has a connection portion 61, partition walls 621 and 622, a terminal block through-hole (through-hole) 63, a fixing portion 64, a fixing partition portion 65, a rib 66, a terminal block recess 67, and an inclined portion 68.

The connection portion 61 connects the conductor 33a and the external terminal 90 and secures them to the terminal block 60. The connection portion 61 has a terminal block screw hole 61b. The terminal block screw hole 61b is aligned with the terminal through-hole 33d in the axial direction and is screwed in place via a connection screw 61a. In this embodiment, the conductor 33a and the external terminal 90 are connected using the connection screw 61a and the terminal block screw hole 61b, but they may also be connected by soldering or other methods.

The partition walls 621 and 622 protrude axially upward (to one axial side) from the top surface (end surface on one axial side) of the terminal block 60. The partition wall 621 is positioned between adjacent conductors 33a. The provision of the partition wall 621 prevents adjacent conductors 33a from contacting each other. It also ensures an insulating distance between adjacent conductors 33a.

A pair of partition walls 622 are arranged at both ends of the terminal block 60 in the parallel direction of the conductors 33a. When viewed from the axial direction, the partition walls 622 extend parallel to the direction in which the conductors 33a extend from the bent portion 33b to the connection portion 61. The partition walls 622 are arranged between the side wall portion 53d and the conductors 33a. The provision of the partition walls 622 prevents contact between the conductors 33a and the side wall portion 53d. Furthermore, an insulating distance can be ensured between the conductors 33a and the side wall portion 53d.

The partition wall 621 has a partition recess 621a and a retaining portion 621b. The partition recess 621a is recessed axially downward (toward the other axial side) from the upper surface (end surface on one axial side) of the partition wall 621. By providing the partition recess 621a, the weight of the terminal block 60 can be reduced.

The retaining portion 621b protrudes from the outer peripheral surface of the partition wall 621 in a direction perpendicular to the axial direction and covers the upper axial side (one axial side) of the conductor 33a. The retaining portion 621b prevents the conductor 33a from coming loose from the terminal block 60.

The terminal block through-hole (through-hole) 63 passes axially through the terminal block 60 and overlaps with the retaining portion 621b in the axial direction. By providing the terminal block through-hole 63, the upper surface of the upper wall portion 53 can be visually observed through the terminal block through-hole 63 when placing the terminal block 60 on the upper wall portion 53. This makes it easy to position the terminal block 60 by, for example, providing a positioning pin on the upper surface of the upper wall portion 53 while checking the positioning pin through the terminal block through-hole 63. This further improves the ease of assembly of the motor 1.

The fixing portion 64 is disposed between adjacent conductors 33a and fixes the terminal block 60 to the housing 50. In this embodiment, the fixing portion 64 has a fixing screw hole 64b. The fixing screw hole 64b is formed by penetrating the terminal block 60 in the axial direction. The fixing screw hole 64b is aligned with the upper wall screw hole 53c in the axial direction and is fastened with the fixing screw 64a. This fixes the terminal block 60 to the upper wall portion 53.

The fixed partition 65 is located on the upper surface (end surface on one axial side) of the terminal block 60, protruding axially upward (to one axial side) from around the fixed portion 64 and positioned between the conductor 33a and the fixed portion 64. In this embodiment, the fixed partition 65 is U-shaped when viewed axially. The provision of the fixed partition 65 prevents contact between the fixed portion 64 and the conductor 33a. It also ensures an insulating distance between the fixed portion 64 and the conductor 33a. The fixed partition 65 may be formed contiguous with the partition wall 621.

In this embodiment, the fixed partition 65 is formed to protrude from the upper surface of the terminal block 60, but it may also be formed to be recessed from the upper surface of the terminal block 60 to the other axial side. In other words, the fixed partition 65 only needs to extend axially from the upper surface (one axial end face) of the terminal block 60 between the conductor 33a and the fixed portion 64.

Furthermore, when viewed from the axial direction, the bent portion 33b and at least a portion of the fixed portion 64 overlap in a direction perpendicular to the direction in which the conductor 33a extends from the bent portion 33b toward the connection portion 61. This allows the bent portion 33b and the fixed portion 64 to be positioned adjacent to each other. Therefore, when the conductor 33a is brought into contact with the terminal block 60 to form the bent portion 33b, rattle of the terminal block 60 relative to the housing 50 can be prevented.

The rib 66 protrudes axially downward (toward the other axial side) from the underside (the end surface on the other axial side) of the terminal block 60. The rib 66 extends from the fixing portion 64 toward the connecting portion 61. This helps prevent deformation of the terminal block 60.

When viewed in the axial direction, the terminal block recess 67 is formed by recessing the outer edge of the terminal block 60 inward. The conductor 33a is placed inside the terminal block recess 67. This prevents the conductor 33a from protruding radially outward from the side surface of the terminal block 60. Therefore, there is no need to increase the radial size of the side wall portion 53d. This further prevents the motor 1 from becoming larger in size in the radial direction. Furthermore, because the conductor 33a is placed in the gap between the terminal block recess 67 and the side wall portion 53d, it is easier to position the conductor 33a, improving workability when routing the conductor 33 and connecting it to the connection portion 61.

The inclined portion 68 is inclined radially outward and axially downward (toward the other axial side) at the outer edge of the terminal block 60. The bent portion 33b is positioned on the inclined portion 68. As a result, the bent portion 33b is less likely to be damaged when it comes into contact with the inclined portion 68 than when it comes into contact with the outer end of the terminal block 60, which does not have the inclined portion 68. Therefore, by bending the conductor 33a along the inclined portion 68, damage to the conductor 33a can be prevented.

The rotation detector 92 is disposed in the axial gap between the housing 50 and the terminal block 60, and the first signal line 71 connected to the rotation detector 92 extends through the gap between the housing 50 and the terminal block 60 in a direction perpendicular to the axial direction (see Figure 3). As a result, the signal line connected to the rotation detector 92 and the conductor 33a are disposed axially separated from each other with the terminal block 60 in between. This ensures an insulation distance between the signal line connected to the rotation detector 92 and the conductor 33a.

The second signal line 72, which is connected to a thermistor (not shown) that detects the temperature of the coil 33 of the stator 30, also extends radially through the gap between the housing 50 and the terminal block 60 (see Figure 3). This ensures an insulating distance between the second signal line 72 connected to the thermistor and the conductor 33a. Note that the thermistor is not limited to detecting the temperature of the coil 33, and may also detect the temperature of the rotor magnet 23 or the housing 50.

The second signal wire 72 extends axially upward from the thermistor and is pulled out axially upward from the upper wall portion 53 through the upper wall through-hole (cover wall through-hole) 53b. The second signal wire 72 passes through the upper wall through-hole 53b, just like the conductor 33a, and there is no need to form a new through-hole in the upper wall portion 53. This reduces the manufacturing cost of the housing 50. Furthermore, pulling out the conductor 33a and the second signal wire 72 from the same upper wall through-hole 53b makes it easier to route the conductor 33a and the second signal wire 72, improving the assembly workability of the motor 1.

Furthermore, the first signal line 71 and the second signal line 72 are bundled together, for example, with a connector to form a bundled signal line 73. The bundled signal line 73 is pulled out to the outside of the housing 50 through the side wall through-hole 53g. That is, the first signal line 71 and the second signal line 72 are bundled together and pulled out to the outside of the housing 50. This makes it easier to route the first signal line 71 and the second signal line 72, improving the ease of assembly of the motor 1.

The above-described embodiments are merely examples of the present invention. The configuration of the embodiments may be modified as appropriate without departing from the technical spirit of the present invention. Furthermore, the embodiments and multiple modified examples may be combined to the extent possible.

The motor of the present invention can be used in an electric power steering device used to assist steering of a vehicle such as an automobile. While the present invention is suitable for power steering devices, it can also be used in other devices such as air blowers.

REFERENCE SIGNS LIST 1 Motor 20 Rotor 21 Shaft 22 Rotor core 23 Rotor magnet 30 Stator 31 Core back portion 32 Teeth portion 33 Coil 33a Conductor 33b Bent portion 33c Connection terminal 33d Terminal through hole 41 Upper bearing (bearing)
42 Lower bearing 50 Housing 51 Peripheral wall portion 52 Bottom wall portion 52a Lower bearing holding portion 53 Upper wall portion (lid wall portion)
53a Upper bearing holding part 53b Upper wall through hole (lid wall through hole)
53c Upper wall screw hole 53d Side wall portion 53e Upper cylinder portion 53f, 53g Side wall through-hole 54 Cover 60 Terminal block 61 Connection portion 61a Connection screw 61b Terminal block screw hole 63 Terminal block through-hole 64 Fixing portion 64a Fixing screw 64b Fixing screw hole 65 Fixing partition portion 66 Rib 67 Terminal block recess 68 Inclined portion 90 External terminal 91 Sensor magnet 92 Rotation detector 621, 622 Partition wall 621a Partition recess 621b Pressing portion C Rotation axis L Center line

Claims (15)

a rotor that rotates around a rotation axis;
a stator facing the rotor across a radial gap and having a conductor forming a coil;
a bearing that rotatably supports the rotor;
a housing that accommodates the rotor, the stator, and the bearing;
a plate-shaped terminal block that is disposed on one axial side of the housing and at least a portion of which overlaps with the bearing in the axial direction,
the terminal block has a connection portion for connecting the conductor wire to an external terminal,
The conductive wire is
a bent portion that is drawn out from the coil to one axial side and bent in a direction perpendicular to the axial direction toward the connection portion,
the connecting portion and the bent portion are spaced apart from each other on the terminal block,
A motor in which the connection portion and the bent portion are arranged on opposite sides of a center line extending radially through the rotation shaft when viewed from the axial direction. the stator has a plurality of phase coils;
The motor according to claim 1 , wherein the plurality of conductors extend in parallel from the bent portion toward the connection portion on the terminal block. The motor described in claim 2, wherein the terminal block has a partition wall that protrudes from one axial end face to one axial direction and is positioned between adjacent conductors. The motor described in claim 3, wherein the partition wall has a partition recess recessed from an end face on one axial side to the other axial side. A motor as described in claim 3 or claim 4, wherein the partition wall has a retaining portion that protrudes in a direction perpendicular to the axial direction and covers one axial side of the conductor. The terminal block has a through hole that penetrates in the axial direction,
The motor according to claim 5 , wherein the through hole overlaps with the pressing portion in the axial direction. The terminal block is
a fixing portion disposed between adjacent conductive wires and fixed to the housing;
The motor according to any one of claims 2 to 6, further comprising a fixed partition portion extending in the axial direction from an end face on one axial side between the conducting wire and the fixed portion. The motor described in claim 7, wherein at least a portion of the bent portion and the fixed portion overlap in a direction perpendicular to the direction in which the conductor extends from the bent portion toward the connection portion, as viewed in the axial direction. the terminal block has a rib that protrudes from an end surface on the other axial side toward the other axial side,
The motor according to claim 7 or 8, wherein the rib extends from the fixed portion toward the connecting portion. The terminal block has a terminal block recess formed by recessing an outer edge portion thereof inward,
The motor according to any one of claims 1 to 9, wherein the conductor is disposed inside the terminal block recess. the terminal block has an inclined portion at an outer edge portion thereof inclined radially outwardly to the other axial side,
The motor according to any one of claims 1 to 10, wherein the bent portion is disposed on the inclined portion. a rotation detector that detects the rotation position of the rotor;
the rotation detector is disposed in an axial gap between the housing and the terminal block,
The motor according to any one of claims 1 to 11, wherein a first signal line connected to the rotation detector extends through the gap in a direction perpendicular to the axial direction. a temperature detector for detecting the temperature of the stator;
The motor according to claim 12 , wherein a second signal line connected to the temperature detector extends through the gap in a direction perpendicular to the axial direction. The housing includes:
a cylindrical peripheral wall portion that radially covers the stator;
a cover wall portion covering one axial end surface of the peripheral wall portion,
the terminal block is disposed on one axial end surface of the cover wall portion,
The motor according to claim 13 , wherein the second signal line passes through a cover wall through-hole that passes through the cover wall portion in the axial direction. The motor described in claim 13 or 14, wherein the first signal line and the second signal line are bundled and drawn out to the outside of the housing.