JP2020137358A - motor - Google Patents

Abstract

To provide a compact motor that is designed to reduce occurrence of failure at the time of attachment.SOLUTION: A motor 1 is an outer rotor type motor, specifically an in-wheel motor incorporated into a wheel. A side surface of a rotor 3 in the motor functions as a wheel. The motor includes: a stator 2; a shaft 20 including a shank 21 extended along a central axis J; the rotor rotated around the central axis; a flange part 25 which is disposed integrally with the shaft and is projected from an outer peripheral surface of the shank toward the outside in a radial direction; and a screw part 22 disposed on one side in an axial direction of the shaft. A surface of the flange part located on a side of the screw part is a flat surface.SELECTED DRAWING: Figure 2

Description

The present invention relates to a motor.

The following Patent Document 1 discloses an in-wheel motor. In-wheel motors are usually fixed to the vehicle by screwing.

International Publication No. 2015/133277

By the way, in recent years, there has been a demand for making the in-wheel motor itself smaller in order to reduce the size and weight of the automatic guided vehicle to which the in-wheel motor is attached. However, if the in-wheel motor is miniaturized, it becomes impossible to secure a space for screwing. Therefore, it is conceivable to form a female screw on one side of the shaft and tighten one side of the shaft with a nut to attach it to the vehicle. However, if the nut is tightened too much, for example, more than the crimping force between the shaft and the motor body at the time of mounting on the vehicle, the shaft may come off from the motor body, causing problems such as malfunction.

In view of the above circumstances, one of the objects of the present invention is to provide a motor that is small in size but suppresses the occurrence of defects during mounting.

One aspect of the motor of the present invention is a stator, a shaft including a shaft portion extending along a central axis, a rotor rotating around the central axis, and an outer peripheral surface of the shaft portion provided integrally with the shaft. A flange portion protruding outward in the radial direction from the shaft and a screw portion provided on one side in the axial direction of the shaft are provided, and the surface of the flange portion on the screw portion side is a flat surface.

According to one aspect of the present invention, there is provided a motor that is compact but suppresses the occurrence of defects during mounting.

FIG. 1 is a diagram showing an overall configuration of an automatic guided vehicle. FIG. 2 is a diagram showing a configuration of a main part of a wheel mounted on a wheel mounting portion. FIG. 3 is a plan view of FIG. 2 from one side in the axial direction. FIG. 4 is a plan view showing a configuration in which the shaft is viewed from one side in the axial direction. FIG. 5 is an exploded view showing a mounting structure of the stator core and the shaft. FIG. 6 is an exploded view showing the main configuration of the motor. FIG. 7 is a diagram showing a configuration of a stator core according to a modified example.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The scope of the present invention is not limited to the following embodiments, and can be arbitrarily changed within the scope of the technical idea of the present invention. The motor of the present embodiment relates to an in-wheel motor incorporated in a wheel of an automatic guided vehicle.

In the drawings below, the scale and number of each structure may differ from the actual structure in order to make each configuration easy to understand. Unless otherwise specified, the direction parallel to the central axis is simply called the "axial direction", the radial direction centered on the central axis is simply called the "diametric direction", and the circumferential direction centered on the central axis, that is, the center. The circumference of the axis is simply called the "circumferential direction". Further, in the following description, the "planar view" means a state viewed from the axial direction. Further, the vertical direction of the transport vehicle placed on the horizontal plane is called "vertical direction", the upper side which is one of the vertical directions is called "upper side", and the lower side which is the other side of the vertical direction is called "lower side".

FIG. 1 is a diagram showing an overall configuration of an automatic guided vehicle.
As shown in FIG. 1, the transport vehicle 100 has a main body 101 and a plurality of (for example, four wheels 102 in this embodiment) wheels 102 provided on the main body 101. The main body 101 includes a top plate 103 and the same number of wheel mounting portions 104 as the wheels 102. The top plate 103 is placed on the upper surface on which the object transported by the transport vehicle 100 is placed. Each wheel 102 is attached to the wheel mounting portion 104. The wheel mounting portion 104 is provided on the lower side of the top plate 103. The wheel mounting portion 104 can swing on the top plate 103 by a suspension (not shown).

FIG. 2 is a diagram showing a main part configuration of the wheel 102 attached to the wheel attachment portion 104.
As shown in FIG. 2, the wheel mounting portion 104 includes a chassis plate 13. The chassis plate 13 is composed of a plate-shaped metal plate. The chassis plate 13 is provided with a mounting hole 13a for mounting the wheel 102.

In the present embodiment, the motor 1 is an outer rotor type motor, which is an in-wheel motor incorporated in the wheels 102. The side surface of the rotor of the motor 1 functions as a wheel of the wheel 102.

The motor 1 is an outer rotor type motor including a stator 2, a rotor 3, a pair of bearings 4a and 4b, a sensor substrate 5, and a shaft 20 extending along a central axis J. The stator 2 has a stator core 34 and a coil 32 mounted on the stator core 34. The center of the shaft 20 coincides with the central axis J. The shaft 20 supports the bearings 4a and 4b, which are a part of the bearing mechanism, in the axial direction, respectively. One end of the shaft 20 is fixed to the chassis plate 13 by a nut 14.

The stator core 34 is formed as a laminated body in which a plurality of plate-like bodies are laminated. A plurality of teeth as magnetic poles are arranged at predetermined intervals in the circumferential direction on the outer peripheral portion of the stator core 34. Further, a coil 32 is wound around an arm portion forming a magnetic circuit inside each tooth via an insulator (not shown). In this way, the stator 2 in which the coil 32 is wound around the stator core 34 is configured.

The rotor 3 is rotatably supported with respect to the stator 2 about the central axis J via bearings 4a and 4b. The rotor 3 has a metal rotor core 33 having a substantially covered cylinder shape centered on the central axis J and having magnetism, and a coil of the stator 2 provided inside (that is, the inner peripheral side) of the side wall portion of the rotor core 33. A magnet 31 is provided so as to face the 32.

The sensor board 5 is provided inside the motor 1. Various electronic components are mounted on the surface of the sensor substrate 5 by soldering or the like. For example, a plurality of Hall elements 6 are mounted on the surface 5a of the sensor substrate 5 facing the rotor 3 on one side in the axial direction. The Hall element 6 detects the rotation angle around the central axis J of the rotor 3 by detecting the change in the magnetic flux leaking from the magnet 31 rotating around the central axis J.

The shaft 20 includes a shaft portion 21 extending along the central axis J. The shaft 20 further has a flange portion 25. The flange portion 25 is provided so as to project outward in the radial direction of the shaft portion 21 of the shaft 20.

The shaft 20 further includes a screw portion 22 provided on one side in the axial direction, an insertion portion (connection portion) 23, and a bearing holding portion 24 provided on the other side in the axial direction. The screw portion 22 is provided at the tip of one of the shafts 20 in the axial direction, and a female screw is formed on the outer peripheral surface. The shaft 20 is fixed to the chassis plate 13 by attaching the nut 14 to the female screw of the screw portion 22.

The insertion portion 23 is a portion that connects the screw portion 22 and the flange portion 25, and is composed of a part of the shaft portion 21. The insertion portion 23 is inserted into the mounting hole 13a of the chassis plate 13. The axial length of the insertion portion 23 corresponds to the thickness of the chassis plate 13, that is, the depth of the mounting hole 13a.

The bearing holding portion 24 is provided at the other tip portion in the axial direction of the shaft 20 and holds the bearing 4b on the outer peripheral surface. The outer diameter of the bearing holding portion 24 is smaller than that of the shaft portion 21.

The flange portion 25 has a first surface 25b formed of a flat surface. The first surface 25b is a surface of the flange portion 25 on the screw portion 22 side in the axial direction. The flange portion 25 holds the bearing 4a on the outer surface 25a. The flange portion 25 has a flange portion 26 on the other side in the axial direction. The brim portion 26 is provided along the circumferential direction of the outer surface 25a of the flange portion 25, and projects radially outward from the outer surface 25a. The brim 26 is in contact with the side surface of the bearing 4a on the other side in the axial direction. In the present embodiment, the flange portion 25 has a function as a guide member for guiding the bearing 4a.

By the way, conventionally, an in-wheel motor has been attached to an automatic guided vehicle by screwing a shaft to the chassis side. In recent years, there has been a demand for a smaller in-wheel motor attached to an automatic guided vehicle in order to reduce the size and weight of the vehicle itself. However, if the in-wheel motor is miniaturized, it becomes impossible to secure a space for screwing.

Therefore, a method of forming a female screw on one side of the shaft and tightening the shaft itself with a nut to attach it to a transport vehicle is also conceivable.
However, for example, when the motor is attached, if the tightening force of the nut becomes too large as the crimping force between the shaft and the motor body, the shaft may come off from the motor body, causing problems such as malfunction.

On the other hand, the motor 1 of the present embodiment includes a shaft 20 having a flange portion 25 integrated with the shaft portion 21. Further, the flange portion 25 has a first surface 25b on the screw portion 22 side formed of a flat surface.

As a result, when the nut 14 is tightened when the shaft 20 is attached to the chassis plate 13 as described above, not only the shaft portion 21 but also the flange portion 25 integrated with the shaft portion 21 is on the chassis plate 13 side. The force that is pulled by the chassis will work. As a result, the shaft 20 comes into contact with the end surface of the flange portion 25 and the surface of the chassis plate 13. That is, the shaft 20 is fixed to the chassis plate 13 in a state where the first surface 25b made of a flat surface is in surface contact with the surface 13b of the chassis plate 13.

Therefore, according to the motor 1 of the present embodiment, the movement to the nut 14 side is restricted by the surface contact of the first surface 25b of the flange portion 25 integrated with the shaft portion 21 with the surface 13b of the chassis plate 13. .. Therefore, even if the nut 14 is overtightened, the shaft 20 will not be pulled by the nut 14 and come off from the motor body (stator 2). Therefore, it is possible to suppress the occurrence of problems such as malfunction due to the shaft coming off due to overtightening of the nut 14 when the motor 1 is attached.

FIG. 3 is a diagram showing a configuration in which FIG. 2 is viewed in a plan view from one side in the axial direction. In FIG. 3, the vertical direction of the automatic guided vehicle 100 coincides with the direction of the double-headed arrow A. FIG. 4 is an enlarged view of a main part of the shaft 20 viewed from one side in the axial direction. In FIG. 4, the direction of the double-headed arrow A coincides with the vertical direction of the automatic guided vehicle 100.

As shown in FIGS. 3 and 4, the outer shape of the flange portion 25 is circular. The flange portion 25 includes an opening 27 and a notch 28. The opening 27 is provided so as to penetrate the flange portion 25 in the axial direction, and at least the radial inside of the opening 27 has a shape along the outer surface 21a of the shaft portion 21.

At least a part of the radial inner opening end 27a in the opening 27 is flush with the outer surface 21a of the shaft portion 21. In the present embodiment, the opening 27 has an oval shape curved along the circumferential direction. A lead wire extending from the stator 2 side passes through the opening 27 as described later. The lead wire is pulled out from the inside of the motor 1 through the opening 27. The size of the opening 27 is appropriately designed according to the number and thickness of the lead wires extending from the stator 2 side.

The notch 28 is provided on a part of the outer surface 25a of the flange portion 25 and connects to the opening 27 in the radial direction. The notch 28 is provided so as to cut out the entire flange portion 25 in the axial direction. The opening 27 is in a state of communicating with the outside by the notch 28.

The insertion portion 23 has a substantially D-shaped planar shape in which a part of the upper side of the circular outer edge portion is cut in a straight line. That is, the cross section of the insertion portion 23 orthogonal to the central axis J has a non-circular shape. The insertion portion 23 is inserted into the mounting hole 13a of the chassis plate 13 as described above. The inner surface shape of the mounting hole 13a corresponds to the outer shape of the insertion portion 23. In the motor 1 of the present embodiment, since the insertion portion 23 and the mounting hole 13a are each non-circular, the shaft 20 is mounted on the chassis plate 13 in a state where rotation around the central axis J is restricted. The planar shape of the insertion portion 23 is not limited to the above-mentioned D shape as long as the rotation of the shaft 20 with respect to the chassis plate 13 can be regulated.

By the way, in a conventional in-wheel motor, the shaft and the stator are fixed by, for example, screwing. However, when the in-wheel motor is miniaturized, it becomes impossible to secure a space for screwing.

Therefore, it is conceivable to fix the shaft and the stator with an adhesive, but the adhesive is peeled off by transmitting the vibration and impact generated when the transport vehicle is running to the in-wheel motor, which causes problems in terms of durability and reliability. May occur.

On the other hand, in the motor 1 of the present embodiment, the stator 2 and the shaft 20 are satisfactorily fixed by adopting the following configuration, so that the durability and reliability are excellent. Hereinafter, the mounting structure of the stator core 34 and the shaft 20 will be described.

FIG. 5 is an exploded view showing a mounting structure of the stator core 34 and the shaft 20.
As shown in FIG. 5, the shaft 20 has a first groove 29 provided on the outer surface 21a of the shaft 21 so as to extend along the central axis J. The stator core 34 has an insertion hole 35 into which the shaft portion 21 of the shaft 20 is inserted, and a second groove portion 36 provided along the axial direction on the inner peripheral surface 35a of the insertion hole 35.

In the motor 1 of the present embodiment, the stator core 34 and the shaft 20 are fixed by pins 30. The shaft 20 inserts the shaft portion 21 into the insertion hole 35 in a state where the positions in the circumferential direction of the first groove portion 29 and the second groove portion 36 are matched. The pin 30 is inserted into the first groove portion 29 and the second groove portion 36 to fix the pin 30 in a state in which the rotation of the shaft 20 with respect to the stator core 34 in the circumferential direction is restricted.

In the present embodiment, the axial dimension of the pin 30 is equivalent to the axial dimension of the insertion hole 35. The second groove 36 is provided in the entire axial direction of the insertion hole 35. As a result, the pin 30 is inserted into the second groove 36 to fix the shaft 21 of the shaft 20 over the entire axial direction of the insertion hole 35. As described above, the pin 30 functions as a rotation regulating member that regulates the rotation of the shaft 20 with respect to the stator core 34. The axial dimension of the pin 30 may be shorter than the axial dimension of the insertion hole 35.

The shape of the pin 30 is relative to the hole shape formed by the first groove 29 and the second groove 36. In the present embodiment, the inner surface of the first groove 29 is formed of a flat surface, and the inner surface of the second groove 36 is formed of a curved surface. The pin 30 of the present embodiment has a substantially rectangular cross section of a portion inserted into the first groove portion 29, and a substantially circular cross section of a portion inserted into the second groove portion 36. The pin 30 may have a function as a rotation regulating member, and the shape of the pin 30 is not limited to the above shape. For example, the shape of the pin 30 may be columnar or prismatic. In this case, the shapes of the first groove 29 and the second groove 36 change according to the shape of the pin 30.

According to the motor 1 of the present embodiment, the stator core 34 and the shaft 20 can be satisfactorily fixed by using the pin 30, so that the transport vehicle 100 can be fixed as in the case of fixing the shaft and the stator with an adhesive. The adhesive does not peel off because the vibration or impact generated during running is transmitted to the motor 1. Therefore, the rotation of the shaft 20 with respect to the stator core 34 prevents the occurrence of problems such as disconnection of the lead wire drawn from the coil 32 wound around the stator core 34, which will be described later, and the durability is excellent.
Further, since the stator core 34 and the shaft 20 can be fixed at low cost by using the pin 30, the manufacturing cost of the stator 2 can be reduced.

The sensor substrate 5 is held by the shaft 20. The sensor substrate 5 is provided between the stator 2 and the flange portion 25 in the axial direction. The sensor substrate 5 has a plate shape orthogonal to the central axis J. The sensor substrate 5 has a recess 7 and a protrusion 8. The recess 7 has a shape that is recessed inward in the radial direction along the outer surface 21a of the shaft portion 21 of the shaft 20. The protrusion 8 extends radially inward from the circumferential center portion of the outer edge 7a of the recess 7. The center of the outer edge 7a of the recess 7 is located on the central axis J.
In the sensor substrate 5, the plurality of Hall elements 6 are arranged on the outer side in the radial direction of the recess 7 at intervals in the circumferential direction around the central axis J. In the present embodiment, a total of three Hall elements 6 are arranged around the central axis J at intervals of 60 °. The arrangement interval of the Hall elements 6 is not limited to 60 °.

The shaft 20 holds the sensor substrate 5 by inserting the shaft portion 21 into the recess 7. More specifically, in the sensor substrate 5, the shaft portion 21 of the shaft 20 is inserted into the recess 7 with the protrusion 8 fitted in the first groove 29. The sensor substrate 5 is in a state in which rotation in the circumferential direction with respect to the shaft 20 is restricted. Therefore, the sensor substrate 5 can obtain high detection accuracy by reducing the positional deviation in the circumferential direction. Further, by using the shaft 20 for positioning the sensor substrate 5, the assembleability of the motor 1 can be improved.

FIG. 6 is an exploded view showing a main configuration of the motor 1. FIG. 6 shows the peripheral configuration of the stator 2 among the components of the motor 1.
As shown in FIG. 6, the stator 2 includes a lead wire R1 drawn from the coil 32. The lead wire R1 is directly connected to the coil 32 of each of the U phase, V phase, and W phase in the stator 2. The lead wire R1 includes a connector R1t at its tip. Further, the sensor substrate 5 includes a lead wire R2 that outputs the detection result of the Hall element 6 to the outside. The lead wire R2 includes a connector R2t at its tip.

Since the motor 1 of the present embodiment is an outer rotor type, it is necessary to pull out the lead wires R1 and R2 connecting the inside and the outside of the motor from a place different from the rotor 3 which is not affected by the rotation of the motor 1. is there. For example, if the motor is large, it is possible to pull it out through wiring inside the shaft.

However, when the in-wheel motor is miniaturized, there is no space for wiring inside the shaft. Even if the wiring can be passed through the inside of the shaft, if there is no space for the connector to pass through, it will be necessary to connect the connector after passing the wiring inside the shaft, which will extend the assembly time of the motor and increase productivity. It will drop.

On the other hand, in the motor 1 of the present embodiment, the lead wires R1 and R2 can be easily pulled out of the motor 1 through the opening 27 and the notch 28 provided in the flange portion 25 of the shaft 20. The lead wires R1 and R2 are drawn out along the outer surface 21a of the shaft portion 21 of the shaft 20 to one side in the axial direction (screw portion 22 side). The opening 27 and the notch 28 provided in the flange portion 25 also function as a reference for the assembling position of each part (coil 32 and stator core 34) with respect to the shaft portion 21 of the shaft 20, thus improving the assembleability of the motor 1. be able to.

In the present embodiment, as shown in FIGS. 3 and 4, the inside of the opening 27 is in a state of communicating with the outside by the notch 28. Therefore, the lead wires R1 and R2 can be arranged in the opening 27 from the outside in the radial direction via the notch 28.

Therefore, according to the motor 1 of the present embodiment, even if the sizes of the connectors R1t and R2t provided at the tips of the lead wires R1 and R2 are larger than the opening 27, the connectors R1t and R2t are passed through the opening 27. Instead, the lead wires R1 and R2 can be pulled out to one side in the axial direction of the shaft 20 by passing them through the opening 27 through the notch 28.

In the shaft 20 of the present embodiment, since at least a part of the radial inner opening end 27a in the opening 27 is flush with the outer surface 21a of the shaft portion 21, there is a step between the outer surface 21a and the inner surface of the opening 27. Does not occur. Therefore, the lead wires R1 and R2 drawn out to the opening 27 along the outer surface 21a of the shaft portion 21 may have problems such as bending due to a step generated between the opening 27 and the outer surface 21a and damage due to the corner of the step. It is suppressed. Therefore, the occurrence of disconnection in the lead wires R1 and R2 can be suppressed.

As shown in FIG. 4, the flange portion 25 has a thin portion 28a having a thin thickness in the radial direction. The thin portion 28a is divided into two by the notch 28. In the present embodiment, since the notch 28 is located at the center of the opening 27 in the circumferential direction, the lengths of the two thin portions 28a in the circumferential direction are substantially equal.

Here, consider the case where the notch 28 is deviated from the center of the opening 27 in the circumferential direction. In this case, the circumferential length of one of the thin-walled portions 28a is longer than the circumferential length of each thin-walled portion 28a when the notch 28 is provided at the center of the circumferential direction. If the length of the thin portion 28a in the circumferential direction becomes longer than necessary, the mechanical strength of the flange portion 25 decreases. In addition, the balance of mechanical strength becomes poor due to the difference in the lengths of the two thin-walled portions 28a in the circumferential direction.

On the other hand, according to the shaft 20 of the present embodiment, by locating the notch 28 at the center of the opening 27 in the circumferential direction, the lengths of the two thin portion 28a in the circumferential direction can be made uniform. As a result, it is possible to suppress a decrease in the mechanical strength of the flange portion 25 due to the length of the thin portion 28a in the circumferential direction becoming longer than necessary. Further, by aligning the lengths of the two thin-walled portions 28a in the circumferential direction, the strength balance of the flange portion 25 in the circumferential direction can be stabilized.

The lead wires R1 and R2 drawn out to one side in the axial direction of the shaft 20 by the opening 27 are pulled out to the back surface 13d side of the chassis plate 13 by the through holes 13c provided in the chassis plate 13. The connectors R1t and R2t of the lead wires R1 and R2 drawn out to the back surface 13d of the chassis plate 13 are electrically connected to, for example, a control board provided under the top plate 103 (not shown).

As shown in FIG. 3, the motor 1 of the present embodiment is fixed to the chassis plate 13 of the transport vehicle 100 in a state where the position of the opening 27 provided in the flange portion 25 is on the top plate 103 side of the main body portion 101. To. The opening 27 provided in the flange portion 25 is located above the central axis J.

More specifically, the motor 1 of the present embodiment is attached to the main body 101 (chassis plate 13) so that the distance between the opening 27 and the top plate 103 is the shortest. Here, the distance between the opening 27 and the top plate 103 means the distance from the center 27C of the opening 27 to the surface of the top plate 103.
In the motor 1 of the present embodiment, the shaft 20 is attached to the main body 101 so that the opening 27 provided in the flange 25 is located on the uppermost side, that is, the position farthest from the ground.

In the motor 1 used as an in-wheel motor, since the rotor 3 functions as a wheel of the wheel 102, an impact or vibration from the ground is directly transmitted. At that time, when a load is received from the ground, an external force is applied to the shaft 20 which is a fixed portion of the motor 1 with respect to the chassis plate 13.

Here, as a comparative example, consider, for example, a case where the shaft 20 is fixed to the chassis plate 13 so that the opening 27 of the flange portion 25 is located below the central axis J. That is, consider a case where the motor 1 is fixed to the chassis plate 13 so that the opening 27 and the notch 28 are arranged at positions facing the ground.

When the opening 27 and the notch 28 are arranged at positions facing the ground in this way, when the motor 1 receives a load from the ground, the lower portion of the flange portion 25, that is, the opening 27 and the flange portion 25. A force is applied to the portion where the notch 28 is provided. Since the portion provided with the opening 27 and the notch 28 has low mechanical strength, the outer shape may be distorted by an external force, and the outer shape may collapse from the circular shape. If the outer shape of the flange portion 25 is distorted from a circular shape, the bearing 4a held by the flange portion 25 becomes difficult to rotate, which may cause rotation failure of the motor 1.

On the other hand, in the transport vehicle 100 of the present embodiment, the shaft 20 is fixed to the chassis plate 13 in a state where the opening 27 of the flange portion 25 is located above the central axis J. More specifically, the motor 1 of the present embodiment is attached to the chassis plate 13 so that the distance from the opening 27 to the top plate 103 is minimized.

Therefore, in the transport vehicle 100 of the present embodiment, when the motor 1 receives a load from the ground, an external force is applied to the lower portion of the flange portion 25, that is, the portion of the flange portion 25 where the opening 27 and the notch 28 are not provided. Is added. The portion not provided with the opening 27 and the notch 28 has a relatively high mechanical strength as compared with the portion provided with the opening 27 and the notch 28, and is therefore less likely to be affected by an external force. Therefore, it is possible to suppress the occurrence of rotation failure of the motor 1 due to the deformation of the flange portion 25 due to the outer shape being distorted by an external force.

Further, in the motor 1 of the present embodiment, since the notch 28 is provided at the center of the opening 27 in the circumferential direction as described above, the lengths of the two thin portion 28a in the circumferential direction can be made uniform. As a result, it is possible to suppress a decrease in the mechanical strength of the flange portion 25 due to the provision of the notch 28, and to stabilize the strength balance of the flange portion 25 in the circumferential direction. Therefore, the durability of the motor 1 can be further improved by further suppressing the deformation of the flange portion 25 described above.

As described above, according to the motor 1 of the present embodiment, the shaft 20 is provided with the first surface 25b on the chassis plate 13 side of the flange portion 25 integrated with the shaft portion 21 formed of a flat surface. As a result, when the nut 14 is tightened when the shaft 20 is attached to the chassis plate 13, the shaft 20 is brought into the chassis plate 13 in a state where the first surface 25b of the flange portion 25 is in surface contact with the surface 13b of the chassis plate 13. It will be fixed.
As described above, according to the motor 1 of the present embodiment, the movement to the nut 14 side is restricted by the surface contact of the first surface 25b of the flange portion 25 integrated with the shaft portion 21 with the surface 13b of the chassis plate 13. Therefore, even if the nut 14 is overtightened, the shaft 20 will not be pulled by the nut 14 and come off from the motor body (stator 2). Therefore, the motor 1 is provided, which is small in size but suppresses the occurrence of defects during mounting.

Further, according to the motor 1 of the present embodiment, the shaft 21 includes an insertion portion 23 as a connection portion for connecting the screw portion 22 and the flange portion 25 in the axial direction, and the insertion portion 23 has a cross section orthogonal to the central axis J. Since the shaft 20 has a non-circular shape, it can be attached to the chassis plate 13 in a state where the rotation of the shaft 20 around the central axis J is restricted.

Further, according to the motor 1 of the present embodiment, since the flange portion 25 holds the bearing 4a for rotating the rotor 3 on the outer peripheral surface, the flange portion 25 can also be used as a guide member for guiding the bearing 4a.

Although one embodiment of the present invention has been described above, each configuration and a combination thereof in the embodiment are examples, and addition, omission, substitution, and other configurations are added, omitted, replaced, and the like without departing from the spirit of the present invention. It can be changed. Moreover, the present invention is not limited to the embodiments.

For example, in the above embodiment, the case where the pin 30 is used as the rotation regulating member of the shaft 20 with respect to the stator core 34 has been described as an example, but the rotation regulating member is not limited to the pin 30. FIG. 7 is a diagram showing a configuration of a stator core according to a modified example. As shown in FIG. 7, the stator core 34 of the modified example has a columnar portion 37 provided on the inner peripheral surface 35a of the insertion hole 35 into which the shaft portion 21 of the shaft 20 is inserted.

In this modification, the stator core 34 and the shaft 20 are fixed by a columnar member 37. The shaft 20 inserts the shaft portion 21 into the insertion hole 35 in a state where the positions of the first groove portion 29 and the columnar member 37 in the circumferential direction are matched. The columnar member 37 is inserted into the first groove 29 to fix the shaft 20 with respect to the stator core 34 in a state in which the rotation of the shaft 20 in the circumferential direction is restricted.

The columnar member 37 is provided over the entire insertion hole 35 in the axial direction. Therefore, the columnar member 37 can fix the shaft portion 21 of the shaft 20 over the entire axial direction of the insertion hole 35. In this way, the columnar member 37 functions as a rotation regulating member that regulates the rotation of the shaft 20 with respect to the stator core 34.

According to the configuration of this modification, the stator 2 can be assembled by a simple process such as inserting the shaft 20 into the stator core 34. Therefore, the manufacturing cost of the stator 2 can be reduced.

Further, in the above embodiment, the case where at least the radial inside of the opening 27 has a shape along the outer surface 21a of the shaft portion 21 has been described as an example, but the present invention is not limited to this, and the opening 27 is the lead wire R1,. As long as R2 can be pulled out, the inner side in the radial direction may have a shape that does not follow the outer surface 21a of the shaft portion 21.

In the above embodiment, the case where the opening 27 has an elliptical shape curved along the circumferential direction has been described as an example, but the present invention is not limited to this, and the opening 27 may draw out the lead wires R1 and R2. For example, it may be rectangular, elliptical, circular, triangular, or the like.

1 ... motor, 2 ... stator, 3 ... rotor, 4a, 4b ... bearing, 5a ... surface, 20 ... shaft, 21 ... shaft part, 22 ... screw part, 23 ... insertion part (connection part), 25 ... flange part, 26 ... Department, 27C ... Center, J ... Central axis.

Claims (3)

With the stator
A shaft that includes a shaft that extends along the central axis,
A rotor that rotates around the central axis and
A flange portion that is integrally provided with the shaft portion and projects radially outward from the outer peripheral surface of the shaft portion.
It is provided with a screw portion provided on one side in the axial direction of the shaft.
A motor whose surface on the threaded portion side of the flange portion is flat. The shaft includes a connecting portion that connects the threaded portion and the flange portion in the axial direction.
The motor according to claim 1, wherein the connecting portion has a non-circular cross section orthogonal to the central axis. The motor according to claim 1 or 2, wherein the flange portion holds a bearing for rotating the rotor on an outer peripheral surface.