Self-starting synchronous motor

Abstract

To provide a self-starting synchronous motor in which deviation of current flowing through a pole head can be suppressed.SOLUTION: A self-starting synchronous motor includes: a casing; a stator housed in the casing; a shaft that is surrounded by the stator and is rotatable about a rotation axis; and a rotor that is mounted on the shaft and that includes a salient pole extending in a radial direction of the rotation axis between the stator and the shaft, a pole head positioned between the salient pole and the stator in the radial direction, a fastening member passing through a hole disposed in the pole head so as to attach the pole head to the salient pole, and a conductive member that is fitted in the hole and comes into contact with the inner circumferential surface of the hole. The pole head and the conductive member are formed of the same material.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a self-starting synchronous motor.

Background Art

[0002] Conventionally, a self-starting synchronous motor including a salient-pole rotor around which windings are wound and a stator around which windings are wound is known. A pole head is attached to the salient pole, for example, by bolts.

[0003] At the start of a self-starting synchronous motor, eddy currents flow on the outer surface of the pole head due to electromagnetic induction by a rotating magnetic field generated from the windings wound around the stator. The rotor starts rotating due to the eddy currents flowing on the outer surface of the pole head.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Holes through which bolts pass are provided on the outer surface of the pole head. Eddy currents flowing on the outer surface of the pole head do not flow into the holes. Therefore, there is a bias in the eddy currents flowing on the outer surface of the pole head, and the pole head may locally generate heat.

[0006] An example of the problem to be solved by the present invention is to provide a self-starting synchronous motor capable of suppressing the bias of the current flowing through the pole head.

Means for Solving the Problems

[0007] A self-starting synchronous motor according to an embodiment of the present invention comprises a housing, a stator housed in the housing, a shaft surrounded by the stator and rotatable about a rotation axis, salient poles extending radially in the direction of the rotation axis between the stator and the shaft, a pole head located radially between the salient poles and the stator, a fastening member that passes through a hole provided in the pole head and attaches the pole head to the salient pole, and a conductive member that fits into the hole and contacts the inner circumferential surface of the hole, and a rotor attached to the shaft, wherein the pole head and the conductive member are formed from the same material. The hole has a first hole through which the fastening member passes, and a second hole that communicates with the first hole and into which the conductive member is fitted, and which has a larger cross-section than the first hole. The fastening member has a column portion that passes through the first hole, a head portion provided at the end of the column portion and located in the second hole, which attaches the pole head to the salient pole, and a first male screw protruding from the head and located in the second hole. The conductive member has a first female screw that engages with the first male screw. . [Effects of the Invention]

[0008] According to the rotating electric machine of the present invention, a self-starting synchronous motor capable of suppressing the bias of the current flowing through the pole head can be obtained. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a cross-sectional view of the self-starting synchronous motor of this embodiment. [Figure 2] Figure 2 is a cross-sectional view of the rotor of this embodiment. [Figure 3] Figure 3 is a plan view of the pole head of this embodiment. [Figure 4] Figure 4 is an enlarged cross-sectional view of a part of the rotor of this embodiment. [Figure 5] Figure 5 is an enlarged, exploded cross-sectional view of a portion of the rotor of this embodiment. [Figure 6] Figure 6 is an enlarged cross-sectional view of a part of the rotor of a modified example of this embodiment. [Modes for carrying out the invention]

[0010] The self-starting synchronous motor 1 according to this embodiment will be described below with reference to the drawings. The configuration of the embodiment described below, and the operation and results (effects) brought about by said configuration, are merely examples and are not limited to the following description. In this specification, ordinal numbers are used only to distinguish parts and materials and do not indicate order or priority.

[0011] <Embodiment> Figure 1 is a cross-sectional view of a self-starting synchronous motor 1 according to this embodiment. The self-starting synchronous motor 1 of this embodiment is, for example, a salient-pole synchronous motor. As shown in Figure 1, the self-starting synchronous motor 1 comprises a housing 2, a stator 3, a shaft 4, a rotor 5, and two bearings 6.

[0012] In the following figures, for convenience, three mutually orthogonal directions are defined. The X direction is the direction along the longitudinal direction of the housing 2 and may also be called the front-to-back direction. The Y direction is the direction along the short direction of the housing 2 and may also be called the left-to-right direction. The Z direction is the direction along the vertical direction of the housing 2 and may also be called the up-and-down direction. Note that the expressions indicating directions such as front-to-back, left-to-right, up-and-down in this embodiment are for convenience only and do not limit the position, orientation, or mode of use of the self-starting synchronous motor 1.

[0013] The housing 2 is formed in a box shape from metal or the like. The housing 2 houses the stator 3 and the rotor 5. Openings 21 that open in the X direction are provided at both ends of the housing 2 in the front-to-back direction (X direction).

[0014] The stator 3 comprises a stator core 31 and stator windings 32. The stator core 31 is fixed to the housing 2. The stator core 31 is located radially outside the rotor 5 and is formed in a cylindrical shape surrounding the rotor 5. The stator windings 32 are fixed to the stator core 31 by passing through a plurality of slots (not shown) formed in the inner circumference 31a of the stator core 31 so as to extend in the axial direction.

[0015] The shaft 4 is supported by the housing 2 via two bearings 6 so as to be rotatable about the rotation axis Ax surrounded by the stator 3. In other words, the two bearings 6 support the shaft 4 so as to be rotatable with respect to the housing 2. The rotation axis Ax is, for example, the central axis (center line) of the shaft 4. Note that the rotation axis Ax may be different from the central axis of the shaft 4.

[0016] In the following description, for the sake of convenience, the axial direction, radial direction, and circumferential direction of the rotation axis Ax are defined. The axial direction is the direction along the rotation axis Ax. The radial direction is the direction orthogonal to the rotation axis Ax. The circumferential direction is the direction around the rotation axis Ax. Note that in the following description, unless otherwise specified, the axial direction, radial direction, and circumferential direction are the axial direction, radial direction, and circumferential direction of the rotation axis Ax.

[0017] The shaft 4 extends axially along the rotation axis Ax so as to penetrate the opening 21 of the housing 2. The portion of the shaft 4 between the both axial ends 4a and 4b is housed in the housing 2. On the other hand, the both axial ends 4a and 4b of the shaft 4 protrude outside the housing 2.

[0018] One end 4a is coupled to, for example, various coupling targets. An outer fan is fixed to the other end 4b. The outer fan is covered with, for example, an outer fan cover and rotates integrally with the shaft 4.

[0019] An inner fan 41 is fixed between each of the two bearings 6 and the rotor 5 in the shaft 4. The inner fan 41 rotates integrally with the shaft 4 and circulates cooling gas in the closed space.

[0020] FIG. 2 is a cross-sectional view of the rotor 5 according to the present embodiment. As shown in FIG. 2, the rotor 5 includes a rotor core 51, a plurality of rotor windings 52, a plurality of pole heads 53, a plurality of stud bolts 54, a plurality of nuts 55, and a plurality of brackets 56. Note that the stud bolt 54 is an example of a fastening member, and the nut 55 is an example of a conductive member.

[0021] As shown in Figure 1, the rotor core 51 is attached to the portion of the shaft 4 between the axial ends 4a and 4b. Therefore, the rotor core 51 is housed in the housing 2 and rotates integrally with the shaft 4.

[0022] The two bearings 6 are located in the opening 21 of the housing 2. That is, the rotor core 51 is positioned between the two bearings 6 in the axial direction. The two bearings 6 are, for example, sliding bearings.

[0023] As shown in Figure 2, the rotor core 51 has a central portion 510 and a plurality of salient poles 511. The central portion 510 is attached to the shaft 4. The salient poles 511 project radially outward from the central portion 510 toward the inner circumferential portion 31a of the stator core 31. In other words, the salient poles 511 extend radially along the axis of rotation Ax between the stator 3 and the shaft 4. The inner circumferential portion 31a is, for example, the inner circumferential surface of the stator core 31, or the radially inner end of the stator core 31.

[0024] The rotor winding 52 is wrapped around the side surface 511a of the salient pole 511 of the rotor core 51. In other words, the rotor winding 52 surrounds the salient pole 511. The side surface 511a is the outer surface of the salient pole 511 facing in a direction intersecting the direction in which the salient pole 511 extends (e.g., axial and circumferential directions). The rotor winding 52 is fixed to the salient pole 511, for example, by a bracket 56.

[0025] Each pole head 53 is attached to the radially outer end of the rotation axis Ax of the corresponding salient pole 511. Each pole head 53 protrudes axially and circumferentially from the side surface 511a of the salient pole 511. As a result, each pole head 53 presses against the rotor winding 52 from the radially outer side. Therefore, the pole head 53 is positioned radially between the salient pole 511 and the inner circumference 31a of the stator core 31.

[0026] The pole head 53 has an end face 53a and a bottom face 53b. The end face 53a is an arc-shaped curved surface that faces radially outward and extends substantially in the circumferential direction. The radius of the end face 53a is shorter than the radius of the inner circumference 31a of the stator core 31. Therefore, the end face 53a is spaced apart from the inner circumference 31a, and a gap is formed between the end face 53a and the inner circumference 31a. The center of the end face 53a may be different from the center of the inner circumference 31a of the stator core 31. The end face 53a is also an example of a first outer surface. The bottom face 53b is located on the opposite side of the end face 53a and faces the salient pole 511.

[0027] Figure 3 is a plan view of the pole head 53 according to this embodiment. As shown in Figure 3, the pole head 53 is provided with a plurality of holes 531. In this embodiment, the plurality of holes 531 are opened in two rows, but the number and arrangement of the holes 531 may be changed as appropriate.

[0028] Figure 4 is an enlarged cross-sectional view of a part of the rotor 5 according to this embodiment. As shown in Figure 4, the multiple holes 531 extend radially, penetrate the pole head 53, and open at the end face 53a and the bottom face 53b. The holes 531 communicate with the holes 512 provided in the salient pole 511. Each of the multiple holes 531 has a first hole 531a and a second hole 531b.

[0029] The first hole 531a is part of a hole 531 that opens into the bottom surface 53b of the pole head 53. The second hole 531b is part of a hole 531 that opens into the end surface 53a of the pole head 53. The second hole 531b communicates with the first hole 531a. The second hole 531b is formed so that a nut 55 can be fitted into it. That is, the inner diameter of the second hole 531b is approximately equal to the outer diameter of the nut 55.

[0030] The diameter of the second hole 531b is larger than the diameter of the first hole 531a. In other words, the second hole 531b has a larger cross-section than the first hole 531a. Therefore, a projection 532 is provided in the hole 531. The projection 532 protrudes from the inner circumferential surface 531b1 of the second hole 531b, forming the first hole 531a.

[0031] The inner circumferential surface 531b1 of the second hole 531b is, for example, tapered, narrowing toward the salient pole 511. In other words, the inner circumferential surface 531b1 of the second hole 531b has an inclined portion 531b2 that narrows toward the salient pole 511.

[0032] The stud bolt 54 passes through the hole 531 in the pole head 53 and is inserted into the hole 512 of the salient pole 511. The stud bolt 54 has a column portion 541, a head portion 542, a male thread 543, and a protruding portion 544. The male thread 543 is an example of a first male thread.

[0033] The column portion 541 is the part of the stud bolt 54 that passes through the first hole 531a of the pole head 53 and is inserted into the hole 512 of the salient pole 511. In other words, the outer diameter of the column portion 541 is slightly smaller than the diameter of the first hole 531a.

[0034] As shown in Figure 4, a male screw 541a is provided on the outer circumferential surface of the column portion 541. The male screw 541a engages with a female screw 512a provided on the inner circumferential surface of the hole 512. In this way, the column portion 541 is attached to the hole 512 of the salient pole 511.

[0035] The head 542 is provided at one end 541b of the column portion 541. The head 542 is located in the second hole 531b when the stud bolt 54 is inserted into the hole 531 of the pole head 53.

[0036] The head 542 is cylindrical in shape, with a larger outer diameter than the column portion 541. The head 542 is positioned to contact the projection 532 when the stud bolt 54 is inserted into the hole 531 of the pole head 53. Therefore, the head 542 can cover the first hole 531a. In other words, when the stud bolt 54 is inserted into the hole 531 of the pole head 53 and the hole 512 of the salient pole 511, the head 542 presses against the projection 532 of the pole head 53 from the radial outside. This allows the head 542 to attach the pole head 53 to the salient pole 511.

[0037] The projection 544 protrudes radially outward from the head 542. The male thread 543 is provided on the projection 544. The male thread 543 is located in the second hole 531b when the stud bolt 54 is inserted into the hole 531 of the pole head 53.

[0038] Furthermore, the end face of the protruding portion 544 may be provided with a hole, such as a hexagonal bolt hole (not shown), which allows an operator to rotate the stud bolt 54 using a tool to fit the male thread 541a into the female thread 512a.

[0039] The nut 55 covers the stud bolt 54 and is fitted into the second hole 531b of the pole head 53. The nut 55 is made of the same material as the pole head 53. This reduces the electrical resistance between the pole head 53 and the nut 55.

[0040] Figure 5 is an enlarged exploded cross-sectional view of a part of the rotor 5 according to this embodiment. As shown in Figure 5, the nut 55 has an end face 55a. The end face 55a faces radially outward. The end face 55a is formed to be substantially flat before being fitted into the second hole 531b of the pole head 53 shown in Figure 5.

[0041] In this embodiment, for example, when the nut 55 is fitted into the second hole 531b of the pole head 53, the portion of the nut 55 that is exposed to the outside from the second hole 531b of the pole head 53 is subjected to grinding or polishing processes such as filing. Therefore, the thickness of the nut 55 before filing or polishing is set to a thickness such that it is exposed from the end face 53a of the pole head 53 when the nut 55 is fitted into the second hole 531b of the pole head 53.

[0042] Through grinding and polishing processes such as filing, the end face 55a of the nut 55 becomes an arc-shaped curved surface that extends along the end face 53a of the pole head 53, as shown in Figure 4. This makes it less likely for a step to occur between the end face 55a of the nut 55 and the end face 53a of the pole head 53. Note that the end face 55a is an example of a second outer surface.

[0043] In this embodiment, the thickness of the nut 55 after filing is about 2 to 3 mm. However, the thickness of the nut 55 should be at least 2 mm. Generally, eddy currents flowing through the end face 53a of the pole head 53 flow to a depth of about 2 mm to 3 mm from the end face 53a. Therefore, in this embodiment, eddy currents flowing through the end face 53a of the pole head 53 flow easily through the end face 53a.

[0044] The nut 55 is provided with a recess 551 and two holes 552. The recess 551 is recessed radially outward from the end of the nut 55 on the radially inward side.

[0045] The protruding portion 544 of the stud bolt 54 fits into the recess 551. Therefore, the inner diameter of the recess 551 is approximately equal to the outer diameter of the protruding portion 544. Furthermore, the depth of the recess 551 is slightly longer than the length of the protruding portion 544.

[0046] The two holes 552 are, for example, for a worker to use a tool to fit a nut 55 into the hole 531 of the pole head 53. The holes 552 open into the end face 55a of the nut 55. The size of the holes 552 is extremely small compared to the hole 531, and is small enough not to affect the current flowing through the end face 53a of the pole head 53.

[0047] In this embodiment, two holes 552 are provided, but the number and size of the holes 552 may be changed as appropriate, as long as it does not affect the current flowing through the end face 53a of the pole head 53. Also, the holes 552 may be eliminated by grinding or polishing, such as filing, performed on the end face 55a of the nut 55.

[0048] The nut 55 further has a female thread 553. The female thread 553 is an example of a first female thread. The female thread 553 is provided on the inner circumferential surface of the recess 551. Therefore, the female thread 553 engages with the male thread 543 of the stud bolt 54.

[0049] The outer circumferential surface 55b of the nut 55 that contacts the inner circumferential surface 531b1 of the second hole 531b tapers toward the salient pole 511, similar to the inner circumferential surface 531b1. In other words, the outer circumferential surface 55b of the nut 55 has an inclined portion 554 that tapers toward the salient pole 511.

[0050] This makes it less likely for a gap to form between the outer surface 55b of the nut 55 and the inner surface 531b1 of the second hole 531b when the nut 55 is fitted into the second hole 531b of the pole head 53.

[0051] When starting the self-starting synchronous motor 1, current is passed through the stator winding 32 of the stator 3. The flow of current through the stator winding 32 generates a rotating magnetic field in the stator 3. The rotating magnetic field generated in the stator 3 induces a current, causing eddy currents to flow at the end face 53a of the pole head 53 attached to the salient pole 511. The pole head 53 is then excited by the eddy currents flowing at the end face 53a of the pole head 53, causing the rotor 5 to start rotating.

[0052] The eddy currents flowing at the end face 53a of the pole head 53 flow along the end face 53a of the pole head 53. The end face 55a of the nut 55 fitted into the second hole 531b of the pole head 53 is exposed at the end face 53a of the pole head 53.

[0053] The end face 55a of the nut 55 is an arc-shaped curved surface that follows the end face 53a of the pole head 53. Therefore, the nut 55 fits onto the end face 53a of the pole head 53 with virtually no step. Furthermore, because the outer circumferential surface 55b of the nut 55 tapers towards the salient pole 511, it fits onto the inner circumferential surface 531b1 without any gap into the second hole 531b. As a result, eddy currents flowing through the end face 53a of the pole head 53 flow between the pole head 53 and the nut 55, passing through the inner circumferential surface 531b1 and the outer circumferential surface 55b, which are in contact with each other. Consequently, eddy currents flow more easily across the entire end faces 53a and 55a.

[0054] Furthermore, in this embodiment, the pole head 53 and the nut 55 are formed from the same material, and there is virtually no difference in the electrical resistance between the pole head 53 and the nut 55. Therefore, eddy currents flowing through the end face 53a of the pole head 53 tend to flow across the entire end face 53a.

[0055] Therefore, in the self-starting synchronous motor 1 of this embodiment, it is possible to suppress the bias of the current flowing through the pole head 53.

[0056] As described above, the self-starting synchronous motor 1 of this embodiment comprises a housing 2, a stator 3, a shaft 4, and a rotor 5. The stator 3 is housed in the housing 2. The shaft 4 is surrounded by the stator 3 and is rotatable around the rotation axis Ax. The rotor 5 is attached to the shaft 4 and has salient poles 511, a pole head 53, a stud bolt 54, and a nut 55. The salient poles 511 extend radially in the direction of the rotation axis Ax between the stator 3 and the shaft 4. The pole head 53 is located radially between the salient poles 511 and the stator 3. The stud bolt 54 passes through a hole 531 provided in the pole head 53 and attaches the pole head 53 to the salient pole 511. The nut 55 is fitted into the hole 531 and contacts the inner circumferential surface 531b1 of the hole 531. The pole head 53 and the nut 55 are made of the same material.

[0057] When the rotor 5 begins to rotate, eddy currents flow through the end face 53a of the pole head 53 due to the rotating magnetic field generated by the stator 3. A nut 55 is fitted into a hole 531 provided in the pole head 53. The pole head 53 and the nut 55 are made of the same material. Therefore, there is virtually no difference in the electrical resistance of the pole head 53 and the nut 55. As a result, the eddy currents flowing through the end face 53a of the pole head 53 tend to flow across the entire end face 53a of the pole head 53, including the end face 55a of the nut 55. Therefore, in the self-starting synchronous motor 1 of this embodiment, it is possible to suppress the bias of the current flowing through the pole head 53.

[0058] Furthermore, in this embodiment, the pole head 53 has a curved end face 53a that faces radially outward. The nut 55 has a curved end face 55a that faces radially outward and extends along the end face 53a of the pole head 53.

[0059] The end face 55a of the nut 55 is aligned with the end face 53a of the pole head 53. Therefore, a step difference is unlikely to occur between the end face 53a of the pole head 53 and the end face 55a of the nut 55. As a result, eddy currents flowing through the end face 53a of the pole head 53 flow across the entire end face 53a of the pole head 53, including the end face 53a of the pole head 53 and the end face 55a of the nut 55. Consequently, the self-starting synchronous motor 1 of this embodiment can suppress the uneven distribution of current flowing through the pole head 53.

[0060] In this embodiment, the hole 531 has a first hole 531a and a second hole 531b. The stud bolt 54 passes through the first hole 531a. The second hole 531b communicates with the first hole 531a, a nut 55 is fitted into it, and has a larger cross-section than the first hole 531a. The stud bolt 54 has a column portion 541, a head portion 542, and a male thread 543. The column portion 541 passes through the first hole 531a. The head portion 542 is provided at the end portion 541b of the column portion 541 and is located in the second hole 531b, and attaches the pole head 53 to the salient pole 511. The male thread 543 protrudes from the head portion 542 and is located in the second hole 531b. The nut 55 has a female thread 553 that engages with the male thread 543.

[0061] The stud bolt 54 attaches the pole head 53 to the salient pole 511 by its head 542, and attaches the nut 55 to the stud bolt 54 by its male thread 543. In other words, the stud bolt 54 attaches the pole head 53 to the salient pole 511 and prevents the nut 55 from flying off due to the centrifugal force caused by the rotation of the rotor 5. This suppresses an increase in the number of parts of the self-starting synchronous motor 1 and prevents the pole head 53 from flying off due to the centrifugal force caused by the rotation of the rotor 5.

[0062] Furthermore, in this embodiment, the outer circumferential surface 55b of the nut 55 contacts the inner circumferential surface 531b1 of the second hole 531b. The outer circumferential surface 55b of the nut 55 and the inner circumferential surface 531b1 of the second hole 531b each taper towards the salient pole 511.

[0063] When a nut 55 is fitted into the second hole 531b provided in the pole head 53, a gap may occur between the inner circumferential surface 531b1 of the second hole 531b and the outer circumferential surface 55b of the nut 55. This gap decreases as the nut 55 is fitted into the second hole 531b because the inner circumferential surface 531b1 of the second hole 531b and the outer circumferential surface 55b of the nut 55 taper towards the salient pole 511. As a result, a gap is less likely to occur between the inner circumferential surface 531b1 of the second hole 531b and the outer circumferential surface 55b of the nut 55.

[0064] (modified version) In this embodiment, the stud bolt 54 and nut 55 make it less likely for steps and gaps to occur at the end face 53a of the pole head 53. However, the configuration for making steps and gaps less likely to occur at the end face 53a of the pole head 53 is not limited to this.

[0065] Figure 6 is an enlarged cross-sectional view of a part of the rotor 5A of a modified example according to this embodiment. As shown in Figure 6, the rotor 5A of the modified example has the same configuration as the rotor 5 of the above embodiment, except for the configuration described below. Therefore, the same effects based on the configuration as in the above embodiment can be obtained with this modified example as well.

[0066] In this modified example, the rotor 5A has a nut 55A that is different from the nut 55 in the above embodiment. Furthermore, the inner circumferential surface 531b1 of the second hole 531b of the pole head 53 does not taper toward the salient pole 511, but has a substantially constant inner diameter. The pole head 53 has an internal thread 533 on its inner circumferential surface 531b1. Note that the internal thread 533 is an example of a second internal thread.

[0067] The nut 55A has a male thread 555 on its outer circumferential surface 55b. The male thread 555 is an example of a second male thread. The male thread 555 engages with a female thread 533 provided on the inner circumferential surface 531b1 of the second hole 531b. Therefore, the gap between the outer circumferential surface 55b of the nut 55A and the inner circumferential surface 531b1 of the second hole 531b of the pole head 53 is filled by the engagement of the male thread 555 and the female thread 533. As a result, the nut 55A fits into the second hole 531b with virtually no gap.

[0068] The nut 55A is attached to the pole head 53 by the fitting of the male thread 555 and the female thread 533. For this reason, the stud bolt 54 omits the male thread 543 and the protruding portion 544. Furthermore, the nut 55A omits the recess 551.

[0069] As described above, the pole head 53 has a female thread 533 provided on the inner circumferential surface 531b1 of the second hole 531b. The nut 55A has a male thread 555 provided on the outer circumferential surface 55b of the nut 55A that engages with the female thread 533. The nut 55A is fitted into the hole 531 of the pole head 53 by the engagement of the male thread 555 and the female thread 533 provided on the second hole 531b. This further suppresses the scattering of the nut 55A by the centrifugal force caused by the rotation of the rotor 5A.

[0070] Although embodiments of the present invention have been described above, these embodiments are merely examples and are not intended to limit the scope of the invention. The above embodiments can be implemented in various other forms, and various omissions, substitutions, combinations, and modifications can be made without departing from the spirit of the invention. Furthermore, each configuration, shape, and other specifications (structure, type, direction, form, size, length, width, thickness, height, number, arrangement, position, material, etc.) can be modified as appropriate. [Explanation of symbols]

[0071] 1... Self-starting synchronous motor, 2... Housing, 3... Stator, 4... Shaft, 5, 5A... Rotor, 511... Salient pole, 53... Pole head, 53a... End face (first outer surface), 531... Hole, 531a... First hole, 531b... Second hole, 531b1... Inner circumferential surface, 533... Female thread (second female thread), 54... Stud bolt (fastening member), 541... Column section, 541b... End section, 542... Head, 543... Male thread (first male thread), 55, 55A... Nut (conductive member), 55a... End face (second outer surface), 55b... Outer circumferential surface, 553... Female thread (first female thread), 555... Male thread (second male thread), Ax... Rotating shaft.

Claims

1. The casing and The stator housed in the aforementioned housing, A shaft surrounded by the stator and rotatable around the axis of rotation, A rotor is attached to the shaft and comprises: a salient pole extending radially in the direction of the rotation axis between the stator and the shaft; a pole head positioned radially between the salient pole and the stator; a fastening member that passes through a hole provided in the pole head and attaches the pole head to the salient pole; and a conductive member that fits into the hole and contacts the inner circumferential surface of the hole. Equipped with, The pole head and the conductive member are formed from the same material. The hole has a first hole through which the fastening member passes, and a second hole that communicates with the first hole and into which the conductive member is fitted, and which has a larger cross-section than the first hole. The fastening member has a column portion that passes through the first hole, a head portion provided at the end of the column portion and positioned in the second hole, which attaches the pole head to the pole pole, and a first male screw protruding from the head portion and positioned in the second hole. The conductive member has a first female thread that engages with the first male thread. Self-starting synchronous motor.

2. The casing and The stator housed in the aforementioned housing, A shaft surrounded by the stator and rotatable around the axis of rotation, A rotor is attached to the shaft and comprises: a salient pole extending radially in the direction of the rotation axis between the stator and the shaft; a pole head positioned radially between the salient pole and the stator; a fastening member that passes through a hole provided in the pole head and attaches the pole head to the salient pole; and a conductive member that fits into the hole and contacts the inner circumferential surface of the hole. Equipped with, The pole head and the conductive member are formed from the same material. The hole has a first hole through which the fastening member passes, and a second hole that communicates with the first hole and into which the conductive member is fitted, and which has a larger cross-section than the first hole. The fastening member has a column portion that passes through the first hole, and a head portion provided at the end of the column portion, positioned in the second hole, and for attaching the pole head to the pole pole. The pole head has a second female thread provided on the inner circumferential surface of the second hole, The conductive member has a second male thread provided on its outer circumferential surface that engages with the second female thread. Self-starting synchronous motor.

3. The casing and The stator housed in the aforementioned housing, A shaft surrounded by the stator and rotatable around the axis of rotation, A rotor is attached to the shaft and comprises: a salient pole extending radially in the direction of the rotation axis between the stator and the shaft; a pole head positioned radially between the salient pole and the stator; a fastening member that passes through a hole provided in the pole head and attaches the pole head to the salient pole; and a conductive member that is fitted into the hole so as to cover the fastening member and contacts the inner circumferential surface of the hole. Equipped with, The pole head and the conductive member are formed from the same material. Self-starting synchronous motor.

4. The casing and The stator housed in the aforementioned housing, A shaft surrounded by the stator and rotatable around the axis of rotation, A rotor is attached to the shaft and comprises: a salient pole extending radially in the direction of the rotation axis between the stator and the shaft; a pole head positioned radially between the salient pole and the stator; a fastening member that passes through a hole provided in the pole head and attaches the pole head to the salient pole; and a conductive member that fits into the hole and contacts the inner circumferential surface of the hole. Equipped with, The pole head has a first curved outer surface that faces outward in the radial direction, The conductive member has a curved second outer surface that faces outward in the radial direction and extends along the first outer surface. Self-starting synchronous motor.

5. The hole has a first hole through which the fastening member passes, and a second hole that communicates with the first hole and into which the conductive member is fitted, and which has a larger cross-section than the first hole. The fastening member has a column portion that passes through the first hole, a head portion provided at the end of the column portion and positioned in the second hole, which attaches the pole head to the pole pole, and a first male screw protruding from the head portion and positioned in the second hole. The conductive member has a first female thread that engages with the first male thread. A self-starting synchronous motor according to claim 3 or 4.

6. The outer circumferential surface of the conductive member is in contact with the inner circumferential surface of the second hole. The outer circumferential surface of the conductive member and the inner circumferential surface of the second hole each taper toward the salient pole. A self-starting synchronous motor according to claim 1.

7. The outer circumferential surface of the conductive member is in contact with the inner circumferential surface of the second hole. The outer circumferential surface of the conductive member and the inner circumferential surface of the second hole each taper toward the salient pole. The self-starting synchronous motor according to claim 5.

8. The hole has a first hole through which the fastening member passes, and a second hole that communicates with the first hole and into which the conductive member is fitted, and which has a larger cross-section than the first hole. The fastening member has a column portion that passes through the first hole, and a head portion provided at the end of the column portion, positioned in the second hole, and for attaching the pole head to the pole pole. The pole head has a second female thread provided on the inner circumferential surface of the second hole, The conductive member has a second male thread provided on its outer circumferential surface that engages with the second female thread. A self-starting synchronous motor according to claim 3 or 4.

9. The inner circumferential surface of the hole is provided over the entire circumference around the axis of the hole, A self-starting synchronous motor according to claim 3 or 4.

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