JP6358294B2 - Electric motor temperature measurement device - Google Patents

Description

  In the present invention, an optical fiber having a plurality of fiber Bragg grating portions spaced apart as a temperature measuring portion is routed in a permanent magnet accommodating hole extending in the rotor rotation axis direction inside the rotor, and the temperature measuring portion is in contact with the optical fiber. The present invention relates to a temperature measuring device for an electric motor whose temperature is acquired as optical information.

In general, when an electric motor is driven, copper loss due to winding resistance, hysteresis loss that occurs in the core, eddy current loss that occurs in the permanent magnet (the combination of hysteresis loss and eddy current loss is called iron loss), etc. Heat is generated and the temperature of each part of the electric motor rises.
When measuring the temperature of the electric motor, particularly when measuring the temperature of the rotor, the rotor (rotor) rotates at high speed in the stator (stator), so it is generally difficult to measure the temperature of the rotor. there were.

Therefore, the present inventors have already invented an electric motor temperature measurement device (see Patent Document 1) that enables temperature measurement of a rotor that rotates at high speed in a stator.
That is, in an apparatus for measuring the temperature of a rotor in an electric motor having a stator, a rotor, and a rotating shaft connected to the rotor, in particular, the temperature of a permanent magnet embedded in the rotor, the rotating shaft of the electric motor An optical fiber arranged through the inside to the rotor temperature measuring unit (temperature measuring unit), a light source for making light incident on the optical fiber, a photodetector for detecting reflected light from the optical fiber, and a rotating shaft The optical fiber has an optical rotary joint that optically connects the optical fiber to the light source and the photodetector, and the optical fiber reflects only a specific wavelength (Bragg wavelength) component of the incident light. The portion including the FBG sensor in the optical fiber extends in parallel with the rotation axis, and rotates with respect to the temperature measurement unit of the rotor (particularly the permanent magnet). Those which are contactable disposed from the shaft side.

  The conventional structure described in Patent Document 1 already invented by the present inventors has an advantage that the temperature of the rotor rotating at high speed in the stator (particularly, the temperature of the permanent magnet) can be measured with high accuracy.

  However, in the conventional structure disclosed in Patent Document 1 above, the optical fiber is branched into two to form a branch portion so that the FBG sensor at the branch portion reaches each desired position in the permanent magnet in the rotor. As a result, the optical signal is deteriorated according to the number of branches of the optical fiber, and the optical fiber is not right and left uneven (specifically, the output shaft side of the rotor and the non-output shaft side of the rotor are uneven). Since it receives centrifugal force stress, there is room for improvement in terms of temperature measurement accuracy.

JP, 2006-65763, A

  Therefore, according to the present invention, even if the interval between the temperature measuring parts is wide due to the structure of the optical fiber, the temperature measuring part (fiber Bragg grating part) separated from the optical fiber can be arranged at a desired position in the rotor. An object of the present invention is to provide a temperature measuring device for an electric motor.

In the temperature measuring device for an electric motor according to the present invention, an optical fiber having a plurality of fiber Bragg grating portions spaced apart as temperature measuring portions is routed in a permanent magnet accommodating hole extending in the rotor rotation axis direction inside the rotor, and An electric motor temperature measuring device in which a temperature at a location where the temperature measuring unit is in contact is acquired as optical information, wherein the optical fiber has the temperature measuring unit at every predetermined distance, and the optical fiber is connected to one end in the axial direction of the rotor. The optical fiber is drawn into a plurality of loops along a rectangular plane of the permanent magnet so that a plurality of temperature measuring parts are arranged at desired positions outside the permanent magnet. is routed to draw the optical fiber within the rotor, except where the fiber Bragg grating portion is positioned, the surface or the permanent magnet containing a permanent magnet Those fixed by an adhesive to the inner wall parts.
The above-mentioned fiber Bragg grating section has a plurality of Bragg-confused light type optical diffraction gratings installed on the fiber. The distance between the optical diffraction gratings varies depending on the temperature, and the wavelength of reflected light shifts. The temperature can be measured by detecting.

  According to the above configuration, the optical fiber is arranged so as to draw a plurality of loops along the rectangular plane of the permanent magnet even if the interval between the temperature measuring parts is wide due to the structure of the optical fiber. The temperature measuring unit is arranged at a desired position outside the permanent magnet, can measure the temperature at the desired position, can also measure the temperature distribution, and can suppress the deterioration of the optical signal.

  By the way, in order to prevent wavelength interference in optical fibers, the distance between fiber Bragg grating portions is generally wider than the total length in the rotor axial direction, and the optical fiber is simply wired in a single turn structure with respect to the permanent magnet. Then, although it is difficult to arrange the temperature measuring units at a plurality of desired positions, the arrangement described above achieves arranging the plurality of temperature measuring units at desired positions outside the permanent magnet.

  In one embodiment of the present invention, the optical fiber has an oval shape when viewed from the rotor rotation direction, and is arranged so as to be substantially uniform on the rotor output shaft side and the rotor opposite output shaft side. .

  According to the above configuration, since the optical fiber is wired so as to be substantially uniform on the rotor output shaft side and the rotor opposite output shaft side, the optical fiber provided with the temperature measuring portion is not easily subjected to uneven centrifugal force stress, Temperature measurement accuracy can be ensured.

In one embodiment of the invention, cross section derived from the rotor end face of the upper Symbol optical fiber to the rotor outside, in which is adhered and fixed to the rotor end face.

  According to the above configuration, since the optical fiber located in the permanent magnet housing hole and the transition portion of the optical fiber led out of the rotor from the rotor end face are both bonded and fixed, the optical fiber is rotated by the high-speed rotation of the rotor. Vibrating can be prevented and generation of harmonic noise can be prevented.

  In one embodiment of the present invention, the permanent magnet housing hole includes an optical fiber insertion portion positioned on a pair of substantially diagonal lines of the permanent magnet, and the optical fiber is inserted into the optical fiber insertion portion. At the same time, the permanent magnets are arranged so as to form a squirrel-like shape as viewed from the end face side in the rotor output shaft direction or the rotor opposite output shaft direction.

  According to the above configuration, the temperature measuring unit can be arranged at a desired position in the rotor even if the number of rounds of the plurality of loops is small due to the above-described rack-like arrangement structure.

  According to this invention, even if the interval between the temperature measuring parts is wide due to the structure of the optical fiber, the temperature measuring part (fiber Bragg grating part) separated from the optical fiber is arranged at a desired position in the rotor. There is an effect that can.

Sectional drawing which shows the internal structure of the electric motor provided with the temperature measuring device of this invention (A) is the schematic which shows the system configuration | structure of the temperature measuring apparatus of an electric motor, (b) is a perspective view of a permanent magnet. Cross section of rotor (A) is an enlarged sectional view of the main part of FIG. 3, (b) is a partially enlarged sectional view of FIG. 4 (a). Schematic perspective view showing optical fiber wiring structure for permanent magnet Explanatory drawing which shows the arrangement structure of the optical fiber to the permanent magnet as seen from the output shaft tip side (A) The perspective view which shows the other Example of the arrangement structure of the optical fiber with respect to a permanent magnet, (b) is explanatory drawing which shows the structure of Fig.7 (a) in the state seen from the output shaft front end side

Even if the distance between the temperature measuring parts is wide due to the structure of the optical fiber, the temperature measuring part (fiber Bragg grating part) separated from the optical fiber is disposed at a desired position in the rotor. An optical fiber having a plurality of fiber Bragg grating portions spaced apart from each other is routed in a permanent magnet accommodating hole portion extending in the rotor rotation axis direction inside the rotor, and the temperature at the location where the temperature measuring portion contacts is acquired as optical information. In the temperature measuring device for an electric motor, the optical fiber has the temperature measuring unit at every predetermined distance, and the optical fiber is drawn from one end in the axial direction of the rotor into the permanent magnet housing hole outside the permanent magnet. is the optical fiber so that the temperature measuring unit of is placed in the desired position of the permanent magnet external, is routed to draw a plurality of loops along a rectangular plane of the permanent magnet, Optical fibers in serial in the rotor, except where the fiber Bragg grating portion is located, is achieved in construction of Ru is fixed by an adhesive to the surface or the inner wall of the permanent magnet containing hole section of the permanent magnet.

An embodiment of the present invention will be described in detail with reference to the drawings.
The drawing shows a temperature measuring device for an electric motor, FIG. 1 is a sectional view showing the internal structure of the electric motor provided with the temperature measuring device, and FIG. 2A is a schematic diagram showing the system configuration of the temperature measuring device for the electric motor. FIG. 2B is a perspective view of the permanent magnet.

  In FIG. 1, an electric motor 1 of this embodiment is a permanent magnet embedded three-phase AC synchronous motor, and includes a stator 3 (stator) having a coil 2 as an armature winding, and a plurality of field magnets. It has a rotor 5 (stator) provided with a permanent magnet 4 (hereinafter simply referred to as a permanent magnet), and a motor housing 6 that houses the stator 3 and the rotor 5. The motor housing 6 includes a cylindrical portion 6a, an output shaft side bracket portion 6b, and a counter output shaft side bracket portion 6c.

  The stator 3 as a stator includes a stator core 7 formed in a cylindrical shape by stacking annular steel plates (specifically, electromagnetic steel plates). A plurality of teeth portions 8 are formed at equal intervals in the circumferential direction so as to protrude radially inward from the inner periphery of the stator core 7, and each of the teeth portions 8 has any one of the U phase, the V phase, and the W phase. The coil 2 is wound. A three-phase power cable 9 is connected to each coil 2 via a power line (not shown).

The rotor 5 as a rotor includes a rotor core 10 formed in a cylindrical shape by laminating disc-shaped steel plates (specifically, electromagnetic steel plates). Although a minute clearance is formed between the rotor 5 as the rotor and the stator 3 as the stator, the illustration of the minute clearance is omitted for convenience of illustration. An output shaft 11 and a rotating shaft 12 are inserted through the central portion of the rotor core 10 described above. The output shaft 11 and the rotary shaft 12 protrude from the both ends of the rotor core 10 in the axial direction, and are rotatably supported by bearings 13 and 13 provided at the center portions of the bracket portions 6b and 6c of the motor housing 6, respectively. Yes. The rotor core 10, the output shaft 11 and the rotary shaft 12 are fixed to each other and rotate integrally.
The rotor core 10 has a plurality of permanent magnet accommodation holes 14 (also serving as a flux barrier for preventing escape of magnetic flux) extending in the rotor axial direction in the circumferential direction. The permanent magnet 4 is embedded in the hole 14.

  As shown in FIG. 2B, the permanent magnet 4 includes an end surface 4a on the output shaft side in the rotor axial direction, an end surface 4b on the counter-output shaft side in the rotor axial direction, an inner peripheral side end surface 4c, and an outer periphery. The hexahedron includes a side end face 4d, an inner face 4e and an outer face 4f extending inward and outward in the radial direction of the rotor 5 and extending in a direction parallel to the rotor output shaft.

  Further, in this embodiment, the permanent magnet 4 described above is made of rare-earths (Sc (scandium), Y (yttrium), La (lanthanum), Ce (cerium), Pr (praseodymium), Nd (belonging to group IIIa of the periodic table). Neodymium), Pm (promethium), Sm (samarium), Eu (europium), Gd (gadolinium), Tb (terbium), Dy (dysprosium), Ho (holmium), Er (erbium), Tm (thulium), Yb ( Ytterbium) and Lu (lutetium)), but is not limited thereto.

When the electric motor 1 is driven, an alternating current is supplied from the three-phase power cable 9 shown in FIG. 1 to the coil 2 of the stator 3 to generate a rotating magnetic field, and the permanent magnet 4 of the rotor 5 is attracted to the rotating magnetic field. As a result, the rotor 5 rotates and is output from the output shaft 11 as a rotational driving force.
In FIG. 1, 15 is a heat insulating flange, and 16 is an optical fiber extension shaft.

  Next, the system configuration of the temperature measuring device for the electric motor 1 will be described with reference to FIGS. 2, illustration of the motor housing 6, the three-phase power cable 9, the bearing 13 and the like shown in FIG. 1 is omitted. FIG. 5 is a schematic perspective view showing an optical fiber routing structure with respect to the permanent magnet.

  As shown in FIGS. 2 and 5, the temperature measuring device 20 includes a plurality of fiber Bragg grating sections (hereinafter simply referred to as FBG sensors) 21A, 21B, 21C, 21D, which are spaced apart in the longitudinal direction of the fiber. An optical fiber 22 having 21E, 21F, 21G, and 21H (see FIG. 5) is provided. In this embodiment, an optical fiber 22 having a diameter of 0.2 mm is employed.

  For convenience of illustration in FIG. 5, the portions indicated by black circles are the FBG sensors 21 </ b> A to 21 </ b> H, and among these, the FBG sensors 21 </ b> A, 21 </ b> B, 21 </ b> E to 21 </ b> H that are in contact with the permanent magnet 4 are the temperature measuring units 23 to 28. That is, each part other than the FBG sensors 21C and 21D becomes the temperature measuring parts 23 to 28.

  The FBG sensors 21A to 21H are formed with a diffraction grating so that the refractive index periodically changes along the axial direction of the optical fiber core. When light enters the FBG sensors 21A to 21H, Of the light, only a specific wavelength (Bragg wavelength) component corresponding to the interval of the diffraction grating and the refractive index of the optical fiber core is reflected by the diffraction grating, and the other wavelength components are transmitted.

  When the temperature of the FBG sensors 21A to 21H changes to change the interval between the diffraction gratings and the refractive index of the optical fiber core, the Bragg wavelength changes accordingly, and the light reflected by the diffraction gratings of the FBG sensors 21A to 21H. Therefore, the temperature of the diffraction grating portion (the temperature of the permanent magnet 4 with which the temperature measuring units 23 to 28 are in contact) can be measured by detecting the wavelength change (optical information).

  The optical fiber 22 provided with the FBG sensors 21A, 21B, 21E to 21H is disposed from the temperature measuring units 23 to 28 of the rotor 5 via the inside of the rotating shaft 12 of the electric motor 1. The temperature measuring parts 23 to 28 in this embodiment are set on the surfaces of the inner and outer edges of the permanent magnet 4 in the rotor radial direction (see the inner peripheral side end face 4c and the outer peripheral side end face 4d).

  Here, as shown in FIG. 5, since the separation distance between the FBG sensors 21A to 21H existing in the longitudinal direction of the optical fiber 22 provided in the optical fiber 22 is larger than the axial length of the rotor 5, The optical fiber 22 is routed so as to draw a plurality of loops along the rectangular plane of the permanent magnet 4 so that the plurality of temperature measuring units 23 to 28 are arranged at desired positions of the permanent magnet 4. In this embodiment, as shown in FIG. 5, the optical fiber 22 is arranged in a three-turn structure with respect to the peripheral surface portion of the permanent magnet 4.

  As shown in FIG. 2, the temperature measurement device 20 includes a light source 29 that makes light incident on an optical fiber 22 that includes FBG sensors 21 </ b> A to 21 </ b> H, and a photodetector 30 that detects reflected light from the optical fiber 22. It has. Since the light source 29 and the photodetector 30 are provided outside the electric motor 1, the light source 29 and the photodetector 30 are stationary regardless of the operating state of the electric motor 1. On the other hand, the optical fiber 22 including the FBG sensors 21 </ b> A to 21 </ b> H is attached to the rotating shaft 12 and the rotor 5 of the electric motor 1, and therefore rotates together with the rotating shaft 12 and the rotor 5 when the electric motor 1 is driven.

Therefore, an optical rotary joint 31 is provided at the end of the rotary shaft 12 in order to optically connect the stationary light source 29 and photodetector 30 to the rotating optical fiber 22.
An end 22a of an optical fiber 22 including FBG sensors 21A to 21H is connected to the rotary shaft 12 side of the electric motor 1 in the optical rotary joint 31. An optical fiber 32 for external connection connected to the light source 29 and the photodetector 30 is connected to the outside of the electric motor 1 in the optical rotary joint 31. Thereby, even when the electric motor 1 is driven, the light source 29 and the photodetector 30 are optically connected to the optical fiber 22 including the FBG sensors 21A to 21H.
1, 2, and 5, the arrow X <b> 1 indicates the tip direction of the output shaft 11, and the arrow X <b> 2 indicates the direction of the rotating shaft 12 in the rotor 5. In FIG. 5, only the center line of the optical fiber 22 is shown for convenience of illustration.

  Next, the arrangement structure of the permanent magnet 4 and the wiring structure of the optical fiber 22 will be described. 3 is a cross-sectional view of the rotor, FIG. 4 (a) is an enlarged cross-sectional view of the main part of FIG. 3, FIG. 4 (b) is a partial enlarged view of FIG. 4 (a), and FIG. FIG. 6 is a schematic perspective view showing the structure, and FIG. 6 is an explanatory view showing the arrangement structure of the optical fiber with respect to the permanent magnet as viewed from the front end side of the output shaft.

  As shown in FIG. 3, permanent magnet housing holes 14 having a substantially rectangular cross-sectional shape are arranged in the circumferential direction on the outer periphery of the rotor core 10. In this embodiment, a total of 8 sets (8 poles) of permanent magnet receiving holes 14 and 14 arranged so as to form a V-shape that opens outward in the radial direction of the rotor core 10 is taken as one set. Magnet housing holes 14 are arranged at equal intervals in the circumferential direction.

As shown in FIGS. 3 and 4, each of these permanent magnet housing holes 14 is an optical fiber insertion hole 14 a (hereinafter referred to as “outer side insertion”) located in the rotor radial direction outer edge portion (see the outer peripheral side end face 4 d) of the permanent magnet 4. And an optical fiber insertion hole 14b (hereinafter referred to as an inside insertion hole) located at the inner radial edge of the permanent magnet 4 (refer to the inner peripheral side end face 4c), and each of these insertion holes 14a. , 14 b including the permanent magnet accommodating hole 14 is formed so as to penetrate the rotor 5 in the axial direction of the rotor over the entire axial length of the rotor 5.
And the permanent magnet 4 which has the rectangular cross-sectional shape slightly smaller than the said permanent magnet accommodation hole 14 is inserted and fixed to each above-mentioned permanent magnet accommodation hole 14. FIG.

  4 and 5, the optical fiber 22 described above is drawn into the permanent magnet housing hole 14 from one end in the axial direction of the rotor 5, and the optical fiber 22 is connected to the inside insertion hole 14 b and the axis of the rotor 5. The rectangular flat surface of the permanent magnet 4 passes through the outside in the other direction, the outer side insertion hole 14a, and the outside in the axial direction of the rotor 5 so that the plurality of temperature measuring portions 23 to 28 are arranged at desired positions outside the permanent magnet 4. It is routed to draw multiple loops along.

  That is, the optical fiber 22 having a plurality of spaced FBG sensors 21A to 21H is routed in the permanent magnet housing hole 14 extending in the rotation axis direction of the rotor 5 inside the rotor 5, and the temperature measuring units 23 to 28 are arranged. The temperature at the place where the contact is obtained is obtained as optical information (change in wavelength of light).

As shown in FIG. 4, the optical fiber 22 in the rotor 5 has a surface of the permanent magnet 4 (refer to the end faces 4 c and 4 d) or a permanent magnet accommodation hole, except for locations where the FBG sensors 21 </ b> A, 21 </ b> B, 21 </ b> E to 21 </ b> H are located. It is fixed to the inner wall of the portion 14 (in this embodiment, the surface of the permanent magnet 4) with an adhesive 33, and is configured to prevent the generation of harmonic noise due to the vibration of the optical fiber 22. doing.
Further, the connecting portions 22b and 22c (see FIG. 5) once the above-described optical fiber 22 is led out of the rotor 5 are bent on the outer wall surface of the end of the rotor 5 so as not to receive wind pressure when the rotor 5 rotates. Bonded and fixed. Thereby, it is comprised so that generation | occurrence | production of the harmonic noise resulting from vibration of the crossover parts 22b and 22c may also be prevented.
Here, as the above-described adhesive 33, a silicon-based resin as a heat-resistant adhesive is preferable.

  Of the temperature measuring units 23 to 28 shown in FIG. 5, the temperature measuring units 23 and 24 are outer edge temperature measuring units located at the outer edge in the radial direction of the rotor 5, and the temperature measuring units 23 to 28 are temperature measuring units. The parts 25 to 28 are inner edge temperature measuring parts located at the radially inner edge part of the rotor 5.

  Moreover, as shown in FIG. 5, the optical fiber 22 has an oval shape when viewed from the rotor rotation direction, that is, when viewed from the direction orthogonal to the inner surface 4 e or the outer surface 4 f of the permanent magnet 4, and the rotor output shaft side. The optical fiber 22 provided with the temperature measuring sections 23 to 28 is less likely to be subjected to unequal centrifugal stress and ensures temperature measurement accuracy. It is composed. In FIG. 5, CL is the center line of the output shaft 11 and the rotation shaft 12.

  Thus, in the temperature measuring device for the electric motor of the above embodiment, the optical fiber 22 having a plurality of fiber Bragg grating portions (see FBG sensors 21A, 21B, 21E to 21H) separated as the temperature measuring portions 23 to 28 is provided. Electricity is routed in the permanent magnet housing hole 14 extending in the rotor rotation axis direction inside the rotor 5 and the temperature at the location where the temperature measuring units 23 to 28 are in contact is obtained as optical information (see wavelength change of light). A temperature measuring device for a motor, wherein the optical fiber 22 has the temperature measuring parts 23 to 28 at predetermined distances, and the optical fiber 22 is connected to a permanent magnet housing hole outside the permanent magnet 4 from one end in the axial direction of the rotor 5. The plurality of temperature measuring units 23 to 28 are drawn into the portion 14 and a plurality of loops are drawn along the rectangular plane of the permanent magnet 4 so that the temperature measuring portions 23 to 28 are arranged at desired positions outside the permanent magnet 4. Those which are searched (see FIGS. 4 and 5).

  According to this configuration, the optical fiber 22 is arranged so as to draw a plurality of loops along the rectangular plane of the permanent magnet 4 even if the interval between the temperature measuring units 23 to 28 is wide due to the structure of the optical fiber 22. As a result, the plurality of temperature measuring units 23 to 28 are arranged at desired positions outside the permanent magnet 4 and can measure the temperature at the desired position, and can also measure the temperature distribution, and the optical signal. Can be prevented.

  By the way, in order to prevent wavelength interference in optical fibers, the distance between fiber Bragg grating portions is generally wider than the total length in the rotor axial direction, and the optical fiber is simply wired in a single turn structure with respect to the permanent magnet. Then, although it is difficult to arrange | position a temperature measuring part in several desired positions, arranging the several temperature measuring parts 23-28 in the desired position outside the permanent magnet 4 by the said structure was achieved. .

  In one embodiment of the present invention, the optical fiber 22 has an oval shape when viewed from the rotor rotation direction, and is arranged so as to be substantially equal on the rotor output shaft side and the rotor opposite output shaft side. Yes (see FIG. 5).

  According to this configuration, since the optical fiber 22 is routed so as to be substantially uniform on the rotor output shaft side and the rotor counter-output shaft side, the optical fiber 22 including the temperature measuring units 23 to 28 has an uneven centrifugal force. Resisting to stress and ensuring temperature measurement accuracy.

  In one embodiment of the present invention, the optical fiber 22 is bonded and fixed to the surface of the permanent magnet 4 or the inner wall of the permanent magnet housing hole 14 and led out of the rotor end surface of the optical fiber 22 to the outside of the rotor. The bridge portions 22b and 22c thus formed are bonded and fixed to the rotor end surface (see FIGS. 4 and 5; however, the bonding and fixing structure of the bridge portions 22b and 22c is not shown).

  According to this configuration, the optical fiber 22 positioned in the permanent magnet housing hole 14 and the transition portions 22b and 22c of the optical fiber 22 led out of the rotor from the rotor end face are both bonded and fixed. It is possible to prevent the optical fiber 22 from vibrating due to the high-speed rotation of 5, and to prevent generation of harmonic noise.

  FIG. 7A is a perspective view showing another embodiment of the optical fiber routing structure with respect to the permanent magnet, and FIG. 7B shows the structure of FIG. 7A as viewed from the front end side of the output shaft. It is explanatory drawing.

  In this embodiment shown in FIG. 7, the permanent magnet accommodation hole portion 14 includes optical fiber insertion portions 14 c, 14 d, 14 e, 14 f located on a pair of substantially diagonal lines of the permanent magnet 4. Each of these optical fiber insertion portions 14c to 14f also serves as a flux barrier.

As shown in the figure, optical fiber insertion portions 14c and 14e are provided on the inner peripheral side end surface 4c side of the permanent magnet 4, and optical fiber insertion portions 14d and 14f are provided on the outer peripheral side end surface 4d side of the permanent magnet 4. These optical fiber insertion portions 14 c to 14 f are formed through the entire length of the rotor 5 in the axial direction.
Here, the optical fiber insertion portions 14 c and 14 d are located on one approximately diagonal line of the permanent magnet 4, and the optical fiber insertion portions 14 e and 14 f are located on the other approximately diagonal line of the permanent magnet 4. .

  The optical fiber 22 has FBG sensors 21J, 21K, 21L, 21M, 21N, 21O, 21P, and 21Q as fiber Bragg grating portions apart from each other, and among these FBG sensors 21J to 21Q, end faces on the inner peripheral side of the permanent magnet 4 Only the portions in contact with 4c and the outer peripheral side end face 4d are set in the temperature measuring portions 41, 42, 43, and 44.

  As shown in FIG. 7, the above-described optical fiber 22 is drawn into the permanent magnet housing hole 14 from one axial end of the rotor 5, and the optical fiber 22 is inserted into the optical fiber insertion portion 14 c and the other axial end of the rotor 5. External, optical fiber insertion portion 14d, one end in the axial direction of the rotor 5, optical fiber insertion portion 14e, outer end in the axial direction of the rotor 5, optical fiber insertion portion 14f, one end in the axial direction of the rotor 5, optical fiber insertion portion 14c The temperature measuring units 41, 42, 43, 44 are arranged so as to draw a plurality of loops along the rectangular plane of the permanent magnet 4 so that the temperature measuring units 41, 42, 43, 44 are arranged at desired positions outside the permanent magnet 4. It is.

  In this embodiment, as shown in FIG. 7 (b), the optical fiber 22 is routed so as to form a hanging shape when viewed from the end face side of the permanent magnet 4 in the rotor output axis direction by the above-described routing structure. Yes.

  Also in FIG. 7A, for convenience of illustration, the FBG sensors 21J to 21Q are indicated by black circles, and in the same figure, the optical fiber 22 indicates only the center line thereof.

  As described above, in the embodiment shown in FIG. 7, the permanent magnet housing hole portion 14 includes optical fiber insertion portions 14 c, 14 d, 14 e, 14 f located on a pair of substantially diagonal lines of the permanent magnet 4, The optical fiber 22 is inserted into the optical fiber insertion portions 14c to 14f, and is viewed from the end face side of the permanent magnet 4 in the rotor output shaft direction or the rotor opposite output shaft direction (in this embodiment, the rotor output shaft). It is routed so as to form a hooked shape (see from the end face side of the direction) (see FIG. 7).

  According to this configuration, the temperature measuring sections 41 to 44 can be arranged at desired positions in the rotor 5 even if the number of times of the loops is small due to the rack-like arrangement structure.

  Also in the embodiment shown in FIG. 7, other configurations, operations, and effects are almost the same as those in the previous embodiment shown in FIGS. 1 to 6. Are denoted by the same reference numerals, and detailed description thereof is omitted.

In the correspondence between the configuration of the present invention and the above-described embodiment,
The fiber Bragg grating portion of the present invention corresponds to the FBG sensors 21A to 21H and 21J to 21Q of the embodiments.
The present invention is not limited to the configuration of the above-described embodiment.

  For example, in the embodiment shown in FIGS. 5 and 7, when the optical fiber 22 is routed, the optical fiber 22 is first inserted into the inside insertion hole 14 b (or the optical fiber insertion portion 14 c positioned on the inner peripheral side of the permanent magnet 4). However, instead of this, the optical fiber 22 is first drawn from the outer side insertion hole 14a (or the optical fiber insertion portion 14d or 14f located on the outer peripheral side of the permanent magnet 4). After that, a structure in which a loop is arranged may be adopted, and the electric motor is not limited to a three-phase AC synchronous motor.

  As described above, according to the present invention, an optical fiber having a plurality of fiber Bragg grating parts spaced apart as temperature measuring parts is routed in a permanent magnet accommodating hole extending in the rotor rotation axis direction inside the rotor, and the above-described measurement is performed. This is useful for a temperature measuring device for an electric motor in which the temperature at a location where the warming portion is in contact is acquired as optical information.

4 ... Permanent magnet 5 ... Rotor 14 ... Permanent magnet accommodation hole 14c-14f ... Optical fiber insertion part 21A-21H, 21J-21Q ... FBG sensor (fiber Bragg grating part)
22b, 22c ... Crossing part 23-28, 41-44 ... Temperature measuring part

Claims (4)

An optical fiber having a plurality of fiber Bragg grating parts spaced apart as a temperature measuring part is routed in a permanent magnet accommodating hole extending in the rotor rotation axis direction inside the rotor, and the temperature at the point where the temperature measuring part contacts is optical information. A temperature measuring device for an electric motor obtained as
The optical fiber has the temperature measuring unit for each predetermined distance,
While drawing the optical fiber from the axial end of the rotor into the permanent magnet housing hole outside the permanent magnet,
The optical fiber is routed so as to draw a plurality of loops along a rectangular plane of the permanent magnet so that a plurality of temperature measuring units are arranged at desired positions outside the permanent magnet ,
The optical fiber in the rotor is fixed to the surface of the permanent magnet or the inner wall of the permanent magnet housing hole portion with an adhesive except for the location where the fiber Bragg grating portion is located. . 2. The temperature measuring device for an electric motor according to claim 1, wherein the optical fiber has an oval shape when viewed from the rotor rotation direction, and is arranged so as to be substantially even on the rotor output shaft side and the rotor opposite output shaft side. . Crossover portions derived from the rotor end face of the upper Symbol optical fiber to the rotor outside, a temperature measuring device of the electric motor according to claim 1 or 2 is adhered and fixed to the rotor end face. The permanent magnet accommodation hole includes an optical fiber insertion portion positioned on a pair of substantially diagonal lines of the permanent magnet,
The optical fiber is inserted into the optical fiber insertion portion and wired so as to form a stalk when viewed from an end surface side of the permanent magnet in the rotor output shaft direction or the rotor anti-output shaft direction. The temperature measuring apparatus for an electric motor according to any one of claims 3 to 4.

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