JP2023155709A - Magnetic flux measuring device for permanent magnet motor - Google Patents

Abstract

To provide a magnetic flux measuring device for a permanent magnet motor that is capable of performing magnetic flux measurement with high reliability while suppressing reduction in occupancy and motor performance of a stator coil.SOLUTION: A magnetic flux measuring device 100 is a device that measures a magnetic flux of a magnet 35 in a motor 3, the motor including: a rotor 33 containing the magnet 35; and a cylinder stator 34 including a plurality of teeth parts 34b and a stator coil 36 wound on the teeth parts 34 and arranged on the slot 34d. The magnetic flux measuring device 100 comprises: a bridging member 120 that is arranged at a position which is on a radially inner side in the slot 34d and separated from the stator coil 36, the bridging member bridging the adjacent teeth parts 34b; and a search coil 110 that is provided on the cross-linkage member 120 so as to be independent from the stator coil 36 and to face the rotor 33, and that detects the magnetic flux of the magnet 35.SELECTED DRAWING: Figure 3

Description

The present disclosure relates to a magnetic flux measuring device for a permanent magnet motor.

In a permanent magnet motor, a search coil independent of the stator coil is sometimes arranged to measure the magnetic flux of the permanent magnet.

For example, Patent Document 1 proposes arranging a search coil facing the rotor.

Japanese Patent Application Publication No. 2006-304462

Generally, the search coil is generally wound around, for example, the teeth or yoke of the stator, but there are concerns that the stator coil occupancy rate and motor performance will decrease.

On the other hand, in FIG. 3 of Patent Document 1, the search coil is described as being arranged in a slot. However, the slot consists of a gap between adjacent teeth portions, and this document does not describe any specific method for arranging the search coil in the slot.

Therefore, an object of the present disclosure is to provide a magnetic flux measuring device for a permanent magnet motor that enables highly reliable magnetic flux measurement while suppressing deterioration in stator coil occupancy and motor performance.

In order to solve the above problems, one aspect of the magnetic flux measuring device for a permanent magnet motor disclosed herein includes a rotor including a permanent magnet, a plurality of teeth portions disposed on the outer circumferential side of the rotor, and a plurality of teeth portions disposed on the outer circumferential side of the rotor. A device for measuring the magnetic flux of the permanent magnet in a permanent magnet motor having a cylindrical stator including a stator coil wound around the stator coil and arranged in a slot between the adjacent teeth parts, a bridging member disposed on the radially inner side and spaced apart from the stator coil and bridging the adjacent teeth portions; provided on the bridging member so as to be independent of the stator coil and facing the rotor; A search coil for detecting the magnetic flux of the permanent magnet is provided.

In this configuration, the search coil is attached to a bridging member that bridges the radially inner sides of adjacent teeth portions. Thereby, the search coil can be disposed at a position radially inside the slot and spaced apart from the stator coil so as to face the rotor. In this way, it is possible to provide a magnetic flux measuring device for a permanent magnet motor that enables highly reliable magnetic flux measurement while suppressing deterioration in stator coil occupancy and motor performance.

Preferably, the bridging member includes a base portion connected to the adjacent teeth portions, and a bobbin portion provided radially inward of the base portion for winding the search coil.

According to this configuration, the bridging member includes a bobbin portion for winding the search coil, which is provided on the radially inner side of the base, that is, on the rotor side of the base, so that the search coil can be easily wound facing the rotor. Can be installed.

In one embodiment, the bobbin portion is integrally provided with the base portion.

According to this configuration, since the bobbin portion is provided integrally with the base, the number of parts of the bridging member and, by extension, the magnetic flux measuring device can be reduced.

It is preferable that the base portion includes a flat portion on the inside in the radial direction, and the bobbin portion is a protruding portion that projects inward in the radial direction from the flat portion.

According to this configuration, since the bobbin portion is provided on the plane portion, a sufficient space can be secured between the tip portion of the teeth portion and the bobbin portion. This makes it easier to wind the search coil around the bobbin.

It is preferable that an engaging portion for determining a radial position of the search coil is provided at a mutually contacting portion of the teeth portion and the bridging member.

According to this configuration, the bridging member is reliably fixed to the teeth portion by the engaging portion. Further, the radial position of the bridging member and, by extension, the search coil relative to the rotor can be precisely positioned.

In one embodiment, the bobbin portion is separate from the base.

According to this configuration, since the bobbin part is separate from the base part, the search coil can be installed simply by setting the bobbin part around which the search coil is wound to the base part installed in the teeth part. In this way, the installation work of the search coil becomes easier.

The base has a first attachment part for attaching the bobbin part, and the bobbin part has a second attachment part that can fix the bobbin part to the base by being fitted into the first attachment part. It is preferable to have a portion.

According to this configuration, the bobbin section can be attached and fixed to the base by simply fitting the second attachment section into the first attachment section, so that the search coil installation work becomes easy.

It is preferable that the first attachment part is a protrusion that protrudes radially inward from the base, and the second attachment part is a through hole that penetrates the bobbin part in the radial direction.

According to this configuration, the bobbin portion can be attached and fixed to the base with a simple configuration of the protrusion and the through hole, so the search coil installation work becomes easy.

The first attachment portion is formed of the protrusion that is asymmetrically provided with respect to the axial center plane of the base portion, and the second attachment portion is formed of the protrusion that is asymmetrically provided with respect to the axial center plane of the bobbin portion so as to correspond to the protrusion. It is preferable that the through hole is provided in the through hole.

According to this configuration, when the bobbin portion around which the search coil is wound is assembled to the base, it is possible to suppress incorrect assembly in which one axial end side and the other end side are assembled in opposite directions.

Preferably, a plurality of the protrusions are provided, and a plurality of the through holes are provided so as to correspond to the plurality of protrusions.

According to this configuration, the attachment strength of the bobbin part can be improved by providing a plurality of attachment points while suppressing incorrect assembly of the bobbin part.

It is preferable that the bridging member includes, on one axial end side, a locking portion that abuts on one axial end side of the teeth portion.

According to this configuration, the locking portion comes into contact with one end in the axial direction of the tooth portion, thereby restricting movement of the bridging member toward the other end in the axial direction. In this way, the axial position of the search coil wound around the bobbin portion can be accurately positioned.

As described above, according to the present disclosure, it is possible to provide a magnetic flux measurement device for a permanent magnet motor that enables highly reliable magnetic flux measurement while suppressing deterioration in stator coil occupancy and motor performance.

1 is a schematic cross-sectional view of a permanent magnet motor equipped with a magnetic flux measuring device according to a first embodiment. FIG. 2 is a view of the vicinity of a portion of the magnetic flux measuring device of FIG. 1 in which a bridging member and a search coil are provided, viewed from the inside in the radial direction. FIG. 3 is a sectional view taken along line III-III in FIG. 2; FIG. 3 is a view of the bridging member and search coil of FIG. 2 viewed from one end in the axial direction. A diagram corresponding to FIG. 2 of the magnetic flux measuring device according to Embodiment 2 FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. 5; FIG. 4 is a diagram corresponding to the magnetic flux measuring device of FIG. 5. FIG. 6 is an exploded view of the bridging member of the magnetic flux measuring device of FIG. 5;

Hereinafter, embodiments of the present disclosure will be described in detail based on the drawings. The following description of preferred embodiments is merely exemplary in nature and is in no way intended to limit the present disclosure, its applications, or its uses.

(Embodiment 1)
<Permanent magnet motor>
FIG. 1 is a schematic cross-sectional view of a permanent magnet motor 3 including an example of a magnetic flux measuring device according to the present disclosure.

The permanent magnet motor 3 (hereinafter also simply referred to as "motor 3") is a permanent magnet type synchronous motor driven by three-phase alternating current. Applications of the motor 3 are not particularly limited, and include, for example, drive motors for electric vehicles such as hybrid vehicles (HVs) and electric vehicles (EVs), motors for home appliances such as air conditioners, washing machines, and refrigerators. Note that the configuration of the motor 3 is an example, and is not limited to this configuration. The magnetic flux measuring device according to the present disclosure can be applied to any motor equipped with a permanent magnet.

As shown in FIG. 1, the motor 3 generally includes a motor case 31, a shaft 32, a rotor 33, a stator 34, and the like.

The motor case 31 is a container that has a cylindrical space inside thereof, one end surface and the other end surface of which are sealed. The rotor 33 and stator 34 are housed in the motor case 31.

The shaft 32 is rotatably supported by the motor case 31. In addition, in this specification, terms related to directions such as "axial direction", "circumferential direction", "radial direction", "one end side", and "other end side" are used to refer to the shaft unless there is a description specifying the direction. 32 is the standard.

The rotor 33 is a cylindrical member constructed by laminating a plurality of metal plates having an axial hole in the center. By fixing the shaft 32 to the shaft hole of the rotor 33, the rotor 33 is integrated with the shaft 32.

The rotor 33 includes a magnet 35 (permanent magnet) arranged around the entire circumference of the rotor 33 at its outer peripheral portion. The magnet 35 is configured such that south poles and north poles are alternately arranged at equal intervals in the circumferential direction. The magnet 35 may be composed of one cylindrical magnet having a plurality of magnetic poles, or may be composed of a plurality of arc-shaped magnets forming each magnetic pole. Note that the arrangement of the magnets 35 shown in FIG. 1 is only an example, and is not limited to this arrangement. Although FIG. 1 shows a surface magnet type rotor, for example, an embedded magnet type rotor in which magnets are arranged inside the rotor core may be used.

The type and material of the magnet 35 are not particularly limited as long as it is a permanent magnet, and can be selected as appropriate depending on the specifications. Specific examples of permanent magnets include ferrite magnets, neodymium magnets, samarium cobalt magnets, alnico magnets, and the like. As the permanent magnet, from the viewpoint of improving motor performance, it is preferable to use a magnet that has a large coercive force (coercive force) and can maintain magnetic force for a long period of time.

Further, the magnet 35 may be a variable magnetic force magnet configured to be able to vary the magnitude of magnetic force. In this case, a permanent magnet with a relatively small holding force may be employed as the magnet 35 so that the magnetic force can be changed relatively easily.

A cylindrical stator 34 is installed on the outer peripheral side of the rotor 33 with a slight gap from the outer peripheral surface of the rotor 33 (inner rotor type). The stator 34 has a stator core 34a configured by laminating a plurality of metal plates.

The stator core 34a includes an annular yoke portion 34c and a plurality of teeth portions 34b extending radially inward from the yoke portion 34c to a position close to the outer peripheral surface of the rotor 33. The plurality of teeth portions 34b are provided at predetermined intervals in the circumferential direction, and the gaps between adjacent teeth portions 34b form a plurality of slots 34d. A plurality of stator coils 36 arranged in the slots 34d are formed by winding electric wires around the teeth portions 34b in a predetermined order. These stator coils 36 constitute a three-phase coil group consisting of a U-phase, a V-phase, and a W-phase.

<Magnetic flux measuring device for permanent magnet motor>
As shown in FIG. 1, the motor 3 includes a magnetic flux measuring device 100 for measuring the magnetic flux of the magnet 35.

As shown in FIGS. 2 to 4, the magnetic flux measuring device 100 includes a bridging member 120 and a search coil 110.

[Bridging member]
The bridging member 120 is a member provided to bridge the radially inner sides of the adjacent teeth portions 34b, preferably the tip portions 341.

Specifically, as shown in FIG. 1, the bridging member 120 is disposed on the radially inner side of the slot 34d, that is, on the rotor 33 side, and at a position spaced apart from the stator coil 36.

The bridging member 120 is a support member for supporting the search coil 110 and arranging the search coil 110 in the slot 34d.

As shown in FIGS. 2 to 4, the bridging member 120 includes a base portion 121 and a bobbin portion 123.

The base portion 121 is a portion that supports the bobbin portion 123, and is connected to the adjacent teeth portions 34b.

The base 121 is a member that extends in the axial direction from one end of the stator 34 to the other end, preferably from one end to the other end. The axial length of the base 121 is, for example, 1/2 or more and 11/10 or less of the axial thickness of the teeth 34b, preferably approximately the same as the axial thickness of the teeth 34b, although this is not intended to be limiting. . Thereby, a sufficient axial length of the bobbin portion 123 can be ensured.

The radial thickness of the base portion 121 is not particularly limited as long as the base portion 121 does not come into contact with the stator coil 36, and is appropriately determined in consideration of the stability of the installation of the search coil 110, the strength of the bridging member 120, etc. Ru.

A groove 342 (engaging portion) extending from one end of the tip 341 in the axial direction to the other end is formed in the contact surface 341a (contact portion) of the tip 341 of the tooth portion 34b with the base 121. A rib 122 (engaging portion) extending from one axial end side of the base portion 121 to the tip end side and configured to be able to engage with the groove 342 is provided on the contact surface 121b (contact portion) of the base portion 121 with the tip portion 341. It is provided. An engaging portion consisting of the groove 342 and the rib 122 is provided at each of the two contact portions between the teeth portion 34b and the base portion 121. When the ribs 122 engage with the grooves 342, the base portion 121 is reliably fixed to the teeth portions 34b. Further, according to this configuration, the radial position of the base portion 121 and, by extension, the search coil 110 relative to the rotor 33 can be accurately positioned.

The bobbin part 123 is a part for winding the search coil 110.

The bobbin portion 123 is provided integrally with the base portion 121. Thereby, the number of parts of the magnetic flux measuring device 100 can be reduced.

A planar portion 121a having a planar shape is provided on the radially inner side of the base portion 121. The plane portion 121a extends from one end of the base portion 121 in the axial direction to the other end.

The bobbin portion 123 includes a protruding portion that protrudes radially inward from the flat portion 121a. By providing the bobbin portion 123 on the plane portion 121a, a sufficient space between the tip portion 341 of the teeth portion 34b and the bobbin portion 123 can be secured. This makes it easier to wind the search coil 110 around the bobbin portion 123.

The bobbin part 123 is provided in the circumferential center of the flat part 121a so as to extend from one axial end of the flat part 121a to the other end, preferably from one axial end to the other end. That is, the axial height of the bobbin portion 123 is, for example, 1/2 or more and 11/10 or less of the axial thickness of the teeth portion 34b, preferably approximately the same as the axial thickness of the teeth portion 34b, although this is not intended to be limiting. It is. The axial length of the bobbin portion may be shorter or longer than the axial length of the teeth portion, as long as a sufficient amount of magnetic flux interlinking with the search coil can be ensured. If the axial height of the bobbin portion 123 is too small, a sufficient amount of magnetic flux interlinking with the search coil 110 will not be obtained, making measurement difficult. Furthermore, if the length in the axial direction of the bobbin portion 123 is too long, although the amount of magnetic flux can be secured, the portion where the magnetic flux does not interlink increases, which is undesirable from the viewpoint of material procurement for the bridging member 120 and search coil 110, cost, etc. . The axial height of the bobbin portion is preferably approximately the same as the axial thickness of the teeth portion. Thereby, a sufficient amount of magnetic flux interlinking with the search coil 110 can be ensured, making it possible to measure magnetic flux with higher reliability.

The height of the bobbin portion 123 in the radial direction is greater than the thickness of the search coil 110 in the radial direction, and the height may be such that the bobbin portion 123 does not come into contact with the rotor 33. The radial height of the bobbin portion 123 is not particularly limited as long as it is within the range, and is appropriately determined according to the diameter, number of turns, etc. of the electric wire that constitutes the search coil 110.

Note that the radial height of the bobbin portion 123 is equal to or smaller than the radial distance from the flat portion 121a of the base portion 121 to the radially inner surface of the teeth portion 34b, that is, the distal end surface of the tip portion 341. is preferred. As a result, since the tip of the bobbin portion 123 is located radially outward from the tip portion 341 of the teeth portion 34b, contact of the bobbin portion 123 with the rotor 33 can be reliably suppressed even when the motor 3 is operated, for example. .

The circumferential width of the bobbin portion 123 is not particularly limited as long as it can stably hold the search coil 110 and does not allow the search coil 110 to come into contact with the teeth portions 34b. Specifically, for example, the lower limit of the circumferential width of the bobbin portion 123 may be approximately 1/3 of the circumferential width of the search coil 110. Further, the upper limit of the circumferential width of the bobbin portion 123 may be set such that the circumferential width of the search coil 110 is smaller than the circumferential distance between the distal ends 341 of the adjacent teeth portions 34b.

Furthermore, the bridging member 120 includes two locking portions 124 that are provided on one axial end side of the base portion 121 and abut on each of the one end surfaces 344 on the axial one end side of two adjacent teeth portions 34b. . By abutting the surface 124a on the other axial end side of the locking portion 124 with the end surface 344, movement of the bridging member 120 toward the other end in the axial direction is restricted, and the axial position of the bridging member 120 is determined. Ru. In this way, the axial position of the search coil 110 wound around the bobbin portion 123 can be accurately positioned.

Note that the material of the bridging member 120 is preferably a non-magnetic material or an insulating material from the viewpoint of suppressing the influence on motor performance. Specifically, the material of the bridging member 120 includes, for example, a resin material.

[Search coil]
The search coil 110 is a coil for detecting the magnetic flux of the magnet 35, and is made of an electric wire wound independently of the stator coil 36.

When the search coil 110 is arranged to face and be close to the rotor 33, the magnetic flux generated by the magnet 35 interlinks with the search coil 110. A potential is generated at both ends of the search coil in proportion to the time change in the magnetic flux interlinking with the search coil. The magnetic flux of a magnet varies depending on the magnetization state (magnetic force) of the magnet. It is known that there is a proportional relationship between the magnetization state of the magnet and the peak of the potential generated in the search coil or the magnetic flux obtained by time integration. Therefore, by measuring the potential generated in the search coil, we can measure changes in magnetic force due to temperature changes such as heat generation in the motor, and changes in magnetic force when the magnetic force of the magnet is varied when a variable magnetic force magnet is used as the magnet. The magnetization state (magnetic force) of a magnet can be measured.

The search coil 110 is wound around the bobbin portion 123 and is provided at a position close to the rotor 33 so as to face the rotor 33 .

Both ends of the electric wire constituting the search coil 110 are led out to one end side of the stator 34 and connected to a terminal 112 arranged on the locking part 124. As shown in FIG. 1, the terminal 112 is connected to, for example, a flux meter 114 via a cable 113. The flux meter 114 measures the magnetization state (magnetic force) of the magnet 35 based on the potential generated at both ends of the search coil 110.

In the magnetic flux measuring device 100 according to the present embodiment, a search coil is attached to a bridging member 120 that bridges the radially inner sides of adjacent teeth portions 34b. Thereby, the search coil 110 can be arranged at a position radially inside the slot 34d and spaced apart from the stator coil 36 so as to face the rotor 33. In this way, highly reliable magnetic flux measurement is possible while suppressing deterioration in the occupancy of the stator coil 36 and motor performance.

Further, since the search coil 110 is wound around a bobbin portion 123 provided on the radially inner side of the base portion 121 of the bridging member 120, the search coil 110 is disposed at a position close to the rotor 33 and facing the rotor 33. Thereby, the magnetic flux generated by the permanent magnet effectively interlinks with the search coil 110. In this way, the detection accuracy of the potential generated at both ends of the search coil 110 is improved, so that the magnetization state of the permanent magnet can be estimated with high accuracy.

Note that the diameter and number of turns of the electric wire of the search coil are not particularly limited, and the number of turns and wire diameter are determined as appropriate to obtain the potential necessary for measurement. Note that in order to reduce the influence on motor performance, it is preferable that the wire diameter is sufficiently small. Furthermore, when the rotational speed of the motor is low, the change in magnetic flux over time is small, and the potential generated in the search coil is small. Since the potential generated in the search coil is proportional to the number of turns of the search coil, from the viewpoint of noise countermeasures, it is preferable to have a large number of turns.

<Search coil installation method>
The method of installing search coil 110 is not particularly limited. The search coil 110 may be installed by winding an electric wire for the search coil 110 around the bobbin portion 123 after connecting the bridging member 120 to the teeth portion 34b. Conversely, after winding the electric wire for the search coil 110 around the bobbin section 123, the bridging member 120 may be connected to the teeth section 34b.

A method for connecting the bridging member 120 to the teeth portions 34b is, for example, as follows. First, the other end side of the rib 122 of the base portion 121 is inserted from one end side of the groove 342 of the teeth portion 34b. Then, the rib 122 is slid within the groove 342 to a position where the locking portions 124, 124 abut one end surface 344, 344. Thereby, the bridging member 120 can be connected and fixed to the teeth portion 34b.

(Embodiment 2)
Other embodiments according to the present disclosure will be described in detail below. In addition, in the description of these embodiments, the same parts as in Embodiment 1 are given the same reference numerals, and detailed description thereof will be omitted.

5 to 8 show the configuration of a magnetic flux measuring device 100 according to the second embodiment. Note that (a) and (b) of FIG. 8 are views of a portion of the bridging member 120 other than the bobbin portion 123 as viewed from one end in the axial direction and from the inside in the radial direction, respectively. (c) and (d) of FIG. 8 are views of the bobbin portion 123 viewed from one end in the axial direction and from the inside in the radial direction, respectively.

In the magnetic flux measuring device 100 according to the second embodiment, the bobbin section 123 is configured as a separate member from the base section 121. According to this configuration, since it is only necessary to set the bobbin portion 123 around which the search coil 110 is wound to the base portion 121 installed on the teeth portion 34b, the installation work of the search coil 110 is facilitated.

As shown in FIG. 8 and the like, the base portion 121 has a first attachment portion 126 to which the bobbin portion 123 is attached. The first attachment portion 126 is configured by three (plural) protrusions 126a, 126b, and 126c provided on the base portion 121 and protruding inward in the radial direction.

Further, the bobbin section 123 has a second attachment section 128 that can be fitted to the first attachment section 126 to fix the bobbin section 123 to the base section 121 . The second attachment portion 128 is provided at a position corresponding to the first attachment portion 126. The second attachment part 128 is configured with three (plural) through holes 128a, 128b, and 128c that penetrate the bobbin part 123 in the radial direction. That is, in this configuration, the first mounting part 126 is composed of three protrusions 126a, 126b, 126c, and the second mounting part 128 is composed of three through holes 128a, 128b, 128c, so there are three mounting points. In this case, the bobbin section 123 is attached to the base section 121.

According to this configuration, the first attachment part 126 has a simple configuration such as a projection and the second attachment part 128 has a through hole, and by simply fitting the second attachment part 128 into the first attachment part 126, the bobbin part 12 can be attached and fixed to the base 121. This facilitates the installation work of search coil 110.

Note that the protrusions 126a, 126b, and 126c have a cylindrical shape extending in the radial direction. The cross sections of the protrusions 126a and 126b perpendicular to the radial direction have a substantially perfect circular shape. The cross section of the protrusion 126c perpendicular to the radial direction has an oval shape.

That is, the three protrusions 126a, 126b, and 126c constituting the first mounting portion 126 are provided asymmetrically with respect to a cross section perpendicular to the axial direction at the axial center of the base portion 121, that is, the axial center plane P1.

Further, each of the through holes 128a, 128b, and 128c that constitute the second attachment portion 128 also has a shape corresponding to each of the protrusions 126a, 126b, and 126c.

That is, the three through holes 128a, 128b, and 128c constituting the second attachment portion 128 are provided asymmetrically with respect to a cross section perpendicular to the axial direction at the axial center of the bobbin portion 123, that is, the axial center plane P2. .

According to this configuration, when assembling the bobbin part 123 around which the search coil 110 is wound to the base part 121, it is possible to suppress incorrect assembly in which one axial end side and the other end side are assembled in opposite directions.

Moreover, in this configuration, the attachment strength of the bobbin portion 123 can be improved by providing a plurality of attachment points. Note that the number of attachment points is not limited to a plurality, and may be a single attachment point as long as the attachment point is provided asymmetrically with respect to the axial center planes P1 and P2.

In the second embodiment, the tip portion 341 of the tooth portion 34b does not have the groove 342. Instead of the groove 342, a notch 343 is formed on the base 121 side of the distal end surface of the distal end 341. In other words, the distal end of the distal end portion 341 is configured such that the width of the distal end portion 341 in the circumferential direction becomes smaller toward the inner side in the radial direction. The rib 122 of the base portion 121 is provided at a position in the radial direction corresponding to the notch portion 343.

In this configuration, it can be said that the entire contact surface 121b of the base 121 constitutes a groove extending from one end of the base 121 in the axial direction to the other end. It can also be said that the entire contact surface 341a of the teeth portion 34b constitutes a rib that engages with the groove.

Furthermore, in this configuration, since the rib 122 is provided at the radial position corresponding to the notch 343, the circumferential width of the flat portion 121a of the base 121 is smaller than that in the configuration of the first embodiment. There is.

As shown in FIGS. 8(c) and 8(d), the bobbin portion 123 has a guide groove 127 that defines the position where the electric wire of the search coil 110 is wound. The guide groove 127 includes a guide groove 127a provided at both axial ends of the bobbin portion 123, and a guide groove 127b continuous with the guide groove 127a and provided at both circumferential ends. In other words, the guide groove 127 is provided over the entire circumference of the search coil 110 in the winding direction. By forming the guide groove 127, it becomes easy to wind the search coil 110 around the bobbin portion 123, and it becomes easy to hold the search coil 110 after winding.

The guide grooves 127b provided at both ends of the bobbin portion 123 in the circumferential direction are formed to extend from one end of the bobbin portion 123 in the axial direction to the other end. It is preferable that the bobbin portion 123 is configured such that the axial height of the guide grooves 127b provided at both circumferential ends of the bobbin portion 123 is approximately the same as the axial height of the teeth portions 34b. Thereby, a sufficient axial length of the search coil 110 can be secured, and sufficient interlinkage magnetic flux can be secured.

(Other embodiments)
Although the bobbin portion 123 of the first embodiment does not have the guide groove 127, the guide groove 127 may be provided.

The shape and number of the protrusion of the first attachment part 126 and the through-hole of the second attachment part 128 of the second embodiment are not limited to the above configuration as long as they are provided correspondingly.

Further, in the second embodiment, the first attachment part 126 was configured with a protrusion and the second attachment part 128 was configured with a through hole, but if the configuration is such that the bobbin part 123 can be attached to the base 121, the configuration of the second embodiment Not limited to. Specifically, for example, the first attachment portion 126 is a hole provided on the radially inner surface of the base portion 121, and the second attachment portion 128 is a protrusion provided on the radially outer surface of the bobbin portion 123. Good too.

Although it is preferable that the attachment points are provided asymmetrically with respect to the axial center planes P1 and P2 as in the second embodiment, the attachment points are not limited to this configuration.

In the above embodiment, two locking portions 124 are provided, but the present invention is not limited to the above structure as long as the search coil 110 can be reliably positioned in the axial direction. Specifically, for example, only one of the two locking portions 124 may be used, or the two locking portions 124 may be connected.

In the above embodiment, the terminal 112 is provided in each of the two locking portions 124, but the present invention is not limited to this configuration. Terminal 112 may be provided at another location, such as base 121.

In the above embodiment, the bridging member 120 and the search coil 110 are provided in one location of the motor 3, but they may be provided in multiple slots 34d.

The present disclosure is extremely useful because it can provide a magnetic flux measuring device for a permanent magnet motor that enables highly reliable magnetic flux measurement while suppressing deterioration in stator coil occupancy and motor performance.

3 Motor (permanent magnet motor)
33 Rotor 34 Stator 34b Teeth portion 34d Slot 35 Magnet (permanent magnet)
36 Stator coil 100 Magnetic flux measuring device 110 Search coil 120 Bridging member 121 Base 121a Planar part 122 Rib (engaging part)
123 Bobbin part 124 Locking part 342 Groove (engaging part)
343 Notch (engaging part)
126 First attachment portions 126a, 126b, 126c Protrusion 127 Guide groove 128 Second attachment portion 128a, 128b, 128c Through hole P1 (at the base) Axial center plane P2 (at the bobbin portion)

Claims (11)

a rotor including a permanent magnet;
a cylindrical stator that is disposed on the outer peripheral side of the rotor and includes a plurality of teeth, and a stator coil that is wound around the teeth and disposed in a slot between the adjacent teeth;
An apparatus for measuring the magnetic flux of the permanent magnet in a permanent magnet motor having
a bridging member disposed at a position radially inside the slot and spaced apart from the stator coil, and bridging the adjacent teeth portions;
A magnetic flux measuring device for a permanent magnet motor, comprising: a search coil provided on the bridging member so as to be independent of the stator coil and facing the rotor, and for detecting the magnetic flux of the permanent magnet. . In claim 1,
The bridging member is
a base connected to the adjacent teeth portions;
A magnetic flux measuring device for a permanent magnet motor, comprising: a bobbin portion provided on the radially inner side of the base portion for winding the search coil. In claim 2,
A magnetic flux measuring device for a permanent magnet motor, wherein the bobbin portion is integrally provided with the base portion. In claim 2 or claim 3,
The base portion includes a flat portion on the radially inner side,
A magnetic flux measuring device for a permanent magnet motor, wherein the bobbin portion is a protruding portion that protrudes radially inward from the flat portion. In claim 1 or claim 2,
A magnetic flux measuring device for a permanent magnet motor, characterized in that an engaging portion for determining a radial position of the search coil is provided at a mutually contacting portion of the teeth portion and the bridging member. In claim 2,
A magnetic flux measuring device for a permanent magnet motor, wherein the bobbin section is separate from the base section. In claim 6,
The base has a first attachment part for attaching the bobbin part,
A magnetic flux measuring device for a permanent magnet motor, wherein the bobbin part has a second mounting part that can be fitted to the first mounting part to fix the bobbin part to the base part. In claim 7,
The first attachment portion is a protrusion that protrudes radially inward from the base,
A magnetic flux measuring device for a permanent magnet motor, wherein the second mounting portion is a through hole that radially penetrates the bobbin portion. In claim 8,
The first attachment portion is comprised of the protrusion provided asymmetrically with respect to the axial center plane of the base portion,
The magnetic flux measuring device for a permanent magnet motor, wherein the second mounting portion is formed of the through hole provided asymmetrically with respect to the axial center plane of the bobbin portion so as to correspond to the protrusion. In claim 9,
A plurality of the protrusions are provided,
A magnetic flux measuring device for a permanent magnet motor, wherein a plurality of the through holes are provided so as to correspond to the plurality of projections. In claim 1 or claim 2,
The magnetic flux measuring device for a permanent magnet motor, wherein the bridging member includes a locking portion on one axial end side that comes into contact with one axial end side of the teeth portion.