JP2021097490A - Rotor and rotary electric machine - Google Patents

Abstract

To provide a rotor that can weaken magnetic force at low temperatures and increase the magnetic force at high temperatures, and a rotary electric machine that uses this rotor.SOLUTION: A rotor 3 of a rotary electric machine 1 includes a rotor core 4 formed in an annular shape and having a magnet insertion hole 31 extending in the axial direction, a plurality of permanent magnets 5 inserted into the magnet insertion holes 31 and provided along the circumferential direction of the rotor core 4, and a temperature sensitive member 6 that is arranged between the permanent magnets 5 adjacent to each other in the circumferential direction, and extends along the axial direction, and in which the saturation magnetic flux density decreases as the temperature rises. The temperature sensitive member 6 is arranged symmetrically with respect to the d-axis of the rotor 3 when viewed from the axial direction.SELECTED DRAWING: Figure 1

Description

The present invention relates to a rotor and a rotary electric machine.

Conventionally, a configuration of a magnet-embedded rotary electric machine (so-called IPM motor; IPM: Interior Permanent Magnet) in which a permanent magnet is embedded inside a rotor core is known. In these magnet-embedded rotary electric machines, various techniques for adjusting the strength of magnetic flux have been proposed according to the state of rotation of the rotor.

For example, Patent Document 1 includes a variable magnetic force magnet in which the amount of magnetic flux changes, a fixed magnetic force magnet having a larger magnetic force than the variable magnetic force magnet, and a short-circuit coil surrounding a magnetic path portion of the fixed magnetic force magnet and a portion where magnetic flux leaks. The configuration of the rotary electric machine is disclosed. According to the technique described in Patent Document 1, an induced current is generated in the short-circuit coil by a magnetic field generated by a magnetization current penetrating the short-circuit coil. By canceling the magnetic field of the fixed magnetic force magnet by this induced current, it is said that an increase in the magnetization current when the variable magnetic force magnet is magnetized can be suppressed.

International Publication No. 2010/070888

By the way, in the neodymium magnet (permanent magnet) used in this type of magnet-embedded rotary electric machine, the residual magnetic flux density (magnetic force) weakens as the temperature rises. Therefore, it is necessary to design the semiconductor element or the like used in the inverter so that the counter electromotive voltage of the permanent magnet is equal to or less than the withstand voltage of the rotating electric machine under the low temperature condition where the magnetic force is the strongest. On the other hand, it is necessary to secure the required torque in a situation where the rotary electric machine is driven and the rotor becomes hot. Therefore, in a rotary electric machine, there is a demand for a magnetic circuit in which the magnetic force is weakened at a low temperature and the magnetic force is strengthened at a high temperature.

Therefore, an object of the present invention is to provide a rotor capable of weakening the magnetic force at a low temperature and increasing the magnetic force at a high temperature, and a rotary electric machine using the rotor.

In order to solve the above problems, the rotor according to the invention according to claim 1 (for example, the rotor 3 in the first embodiment) is formed in an annular shape and has a magnet insertion hole extending in the axial direction (for example, the first embodiment). (For example, the rotor core 4 in the first embodiment) having the magnet insertion hole 31) and a plurality of permanent magnets (for example, the first embodiment) inserted into the magnet insertion hole and provided along the circumferential direction of the rotor core. A temperature-sensitive member (for example, the first) which is arranged between the permanent magnets 5) adjacent to each other in the circumferential direction, extends along the axial direction, and the saturation magnetic flux density decreases as the temperature rises. It is characterized in that the temperature-sensitive member 6) in one embodiment is provided.

Further, in the rotor according to the invention of claim 2, the rotor core has a temperature sensitive member insertion hole (for example, a temperature sensitive member insertion hole 32 in the first embodiment) into which the temperature sensitive member is inserted. A rib (for example, the rib 35 in the first embodiment) is provided between the temperature-sensitive member insertion hole and the magnet insertion hole, and the corner portion of the temperature-sensitive member insertion hole is formed when viewed from the axial direction. , It is characterized by being chamfered.

Further, the rotor according to the third aspect of the invention is characterized in that the temperature sensitive member is a soft magnetic material.

The rotor according to the fourth aspect of the present invention is characterized in that the temperature sensitive member is arranged symmetrically with respect to the d-axis of the rotor when viewed from the axial direction.

Further, the rotor according to the fifth aspect of the invention is characterized in that it includes an end face plate (for example, the end face plate 7 in the first embodiment) arranged at the axial end portion of the rotor core.

The rotary electric machine according to the invention according to claim 6 (for example, the rotary electric machine 1 in the first embodiment) is a stator (for example, a stator) which is arranged with a gap between the above-mentioned rotor and the outer side in the radial direction of the rotor. It is characterized in that the stator 2) in one embodiment is provided.

According to the rotor according to claim 1 of the present invention, a temperature-sensitive member is arranged between the permanent magnets adjacent to each other in the circumferential direction, and the saturation magnetic flux density of the temperature-sensitive member decreases as the temperature rises. At low temperatures, the saturation magnetic flux density of the temperature sensitive member is relatively large. Therefore, when the magnetic flux passes through the temperature-sensitive member, magnetic flux leakage from the permanent magnet is likely to occur. As a result, the counter electromotive voltage generated in the rotor can be reduced. Therefore, under low temperature conditions, the counter electromotive voltage can be lowered as compared with the conventional technique having no temperature sensitive member, so that the withstand voltage of the semiconductor element used in the inverter can be lowered. Therefore, a cheaper semiconductor element having a lower withstand voltage can be used.
On the other hand, when the rotating electric machine is driven and the temperature rises due to internal heat generation, the saturation magnetic flux density of the temperature sensitive member is smaller than that at low temperature. Therefore, by suppressing the passage of magnetic flux through the temperature-sensitive member, it becomes difficult for magnetic flux leakage from the permanent magnet to occur. As a result, under high temperature conditions, the magnetic force along the radial direction of the permanent magnet can be increased, and the torque of the rotor can be improved. Therefore, a desired torque can be output when the rotary electric machine is driven.
As described above, according to the present invention, it is possible to provide a rotor capable of weakening the magnetic force at a low temperature and increasing the magnetic force at a high temperature.

According to the rotor according to claim 2 of the present invention, a rib is provided between the temperature sensitive member insertion hole and the magnet insertion hole, and the corner portion of the temperature sensitive member insertion hole is formed when viewed from the axial direction. It is chamfered. Therefore, since the corners are not formed on the ribs, it is possible to suppress the concentration of stress on the ribs due to the centrifugal force of the permanent magnet or the temperature sensitive member, for example, when the rotor rotates. Therefore, the rotor can withstand centrifugal force and can reliably hold the temperature-sensitive member.

According to the rotor according to claim 3 of the present invention, the temperature sensitive member is a soft magnetic material. Therefore, the temperature-sensitive member itself does not generate magnetic flux, but is magnetized by the magnetic force of a permanent magnet arranged in the vicinity of the temperature-sensitive member. Therefore, the saturation magnetic flux density of the temperature-sensitive member changes according to the temperature, so that a desired magnetic path can be formed according to the temperature. Therefore, it is possible to effectively weaken the magnetic force at low temperature and increase the magnetic force at high temperature.

According to the rotor according to claim 4 of the present invention, the temperature sensitive members are arranged symmetrically with respect to the d-axis of the rotor when viewed from the axial direction. As a result, the magnetic force of the permanent magnet can be adjusted more effectively. Specifically, when the temperature is low, the leakage flux is generated by allowing the passage of the magnetic flux in the temperature sensitive member, and when the temperature is high, the magnetic force in the radial direction is increased by suppressing the passage of the magnetic flux in the temperature sensitive member. Therefore, the magnetic force can be remarkably changed according to the temperature.

According to claim 5 of the present invention, the rotor includes an end face plate arranged at the axial end of the rotor core. With this end face plate, the movement of the permanent magnet and the temperature sensitive member in the axial direction can be restricted. Further, for example, the refrigerant may be supplied along the radial direction of the rotor via the end face plate. In this case, since the temperature of the rotor can be positively cooled by using the refrigerant, it is easy to adjust the temperature of the rotor. Therefore, by setting the temperature to a desired value, the saturation magnetic flux density of the temperature sensitive member can be set to a desired value.

According to the rotary electric machine according to claim 6 of the present invention, the rotor and the stator are provided. As a result, it is possible to use an inexpensive semiconductor element having a low withstand voltage in the inverter by weakening the magnetic force at a low temperature, and to provide a high-performance rotary electric machine using a rotor having an improved torque by increasing the magnetic force at a high temperature. ..

The partial front view of the rotary electric machine which concerns on 1st Embodiment. FIG. 1 is an enlarged view of part II. An exploded perspective view of the rotor core and the temperature sensitive member according to the first embodiment. The graph which shows the relationship between the temperature and the saturation magnetic flux density in the temperature sensitive member which concerns on 1st Embodiment. The explanatory view which shows the magnetic flux density distribution at a low temperature of the rotary electric machine which concerns on 1st Embodiment. The explanatory view which shows the magnetic flux density distribution at the high temperature of the rotary electric machine which concerns on 1st Embodiment. The graph which shows the back electromotive voltage waveform at the time of no load of the rotary electric machine which concerns on 1st Embodiment. The partial front view of the rotary electric machine of the rotary electric machine which concerns on 2nd Embodiment. The partial front view of the rotary electric machine of the rotary electric machine which concerns on 3rd Embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First Embodiment)
(Rotating machine)
FIG. 1 is a partial front view of the rotary electric machine 1 according to the first embodiment. FIG. 2 is an enlarged view of part II of FIG.
As shown in FIG. 1, the rotary electric machine 1 is a traveling motor mounted on a vehicle such as a hybrid vehicle or an electric vehicle. However, the configuration of the present invention is applicable not only to a traveling motor, but also to a power generation motor, a motor for other purposes, and a rotary electric machine 1 (including a generator) other than for vehicles.
The rotary electric machine 1 includes a stator 2 and a rotor 3. In the following description, the direction along the axis C, which is the central axis of the stator 2 and the rotor 3, is simply referred to as the axial direction, the direction orthogonal to the axis C is referred to as the radial direction, and the direction around the axis C is referred to as the circumferential direction. is there.

(Stator)
The stator 2 is formed in an annular shape centered on the axis C. The outer peripheral portion of the stator 2 is fixed to the inner wall surface of a case (not shown). The case houses the stator 2 and the rotor 3 inside. A refrigerant (not shown) is housed inside the case. The stator 2 and the rotor 3 described above are arranged inside the case in a state where a part of the stator 2 and the rotor 3 is immersed in the refrigerant. As the refrigerant, ATF (Automatic Transmission Fluid) or the like, which is a hydraulic oil used for lubrication of a transmission, power transmission, or the like, is preferably used.
The stator 2 has a stator core 21 and a coil 22.

The stator core 21 is a laminated core formed by laminating a plurality of steel plates in the axial direction. The stator core 21 is formed in an annular shape centered on the axis C. The stator core 21 has a plurality of teeth 23 protruding inward in the radial direction from the inner peripheral portion of the stator core 21. A plurality of teeth 23 are provided in the circumferential direction. Slots 24 are formed between the teeth 23.

The coil 22 is inserted into the slot 24 of the stator core 21. The coil 22 is mounted on the stator core 21, for example, by inserting a plurality of copper wire segments into the slots 24. The coil 22 has a coil insertion portion 22a inserted into the slot 24 of the stator core 21 and coil ends (not shown) protruding from the stator core 21 on both sides in the axial direction.

(Rotor)
The rotor 3 is formed in an annular shape. The rotors 3 are arranged at intervals on the inner side in the radial direction with respect to the stator 2. The rotor 3 is configured to be rotatable around the axis C. The rotor 3 energizes the coil 22 mounted on the stator 2 and generates a magnetic field between the stator 2 and the rotor 3, so that the rotor 3 rotates about the axis C with respect to the stator 2.
The rotor 3 includes a rotor core 4, a permanent magnet 5, a temperature sensitive member 6, and an end face plate 7.

(Rotor core)
The rotor core 4 is formed in an annular shape centered on the axis C. The rotor core 4 is a laminated core formed by laminating a plurality of steel plates in the axial direction. The rotor core 4 has a magnet insertion hole 31, a temperature sensitive member insertion hole 32, a shaft insertion hole 33, and a rib 35.

The magnet insertion hole 31 is provided on the outer peripheral portion of the rotor core 4. The magnet insertion hole 31 penetrates the rotor core 4 in the axial direction. A pair of magnet insertion holes 31 are provided side by side in the circumferential direction with a straight line L passing through the axis C and extending in the radial direction when viewed from the axial direction. The pair of magnet insertion holes 31 are inclined from the inside to the outside in the radial direction as they are separated from the straight line L in the circumferential direction when viewed from the axial direction. In other words, the pair of magnet insertion holes 31 are arranged in a V shape so as to be separated from each other from the inside to the outside in the radial direction. A plurality (8 in this embodiment) of the pair of magnet insertion holes 31 thus formed are provided at equal intervals in the circumferential direction. The straight line L coincides with the d-axis of the rotor 3.

The temperature sensitive member insertion hole 32 is provided between the pair of magnet insertion holes 31. Specifically, the temperature sensitive member insertion hole 32 is arranged on the d-axis between the pair of magnet insertion holes 31 when viewed from the axial direction. The temperature sensitive member insertion hole 32 is provided at a position corresponding to the end portion of the pair of magnet insertion holes 31 in the radial direction. The temperature sensitive member insertion hole 32 penetrates the rotor core 4 in the axial direction. The temperature-sensitive member insertion hole 32 is formed in a rectangular shape with chamfered corners when viewed from the axial direction.

The shaft insertion hole 33 is provided inside the magnet insertion hole 31 and the temperature sensitive member insertion hole 32 in the radial direction. The shaft insertion hole 33 penetrates the rotor core 4 in the axial direction. The shaft insertion hole 33 is provided coaxially with the axis C. A shaft (not shown) is inserted into the shaft insertion hole 33. The shaft is formed in a tubular shape centered on the axis C. The shaft is fixed by being press-fitted into, for example, the shaft insertion hole 33. The shaft is rotatably supported with respect to the case via bearings (not shown) attached to the case accommodating the rotor 3 and the stator 2. As a result, the rotor core 4 and the shaft rotate integrally around the axis C.

As shown in FIG. 2, the rib 35 is provided between the magnet insertion hole 31 and the temperature sensitive member insertion hole 32. When viewed from the axial direction, the rib 35 has a circumferential direction as a thickness direction and extends along a radial direction. The ribs 35 are provided on both sides of the temperature sensitive member insertion hole 32 in the circumferential direction.

(permanent magnet)
As shown in FIG. 1, the permanent magnet 5 is inserted into each magnet insertion hole 31 of the rotor core 4. A plurality of permanent magnets 5 are provided in the circumferential direction. The permanent magnet 5 is formed in a rectangular shape when viewed from the axial direction. The permanent magnet 5 extends along the axial direction. The pair of permanent magnets 5 inserted into the pair of magnet insertion holes 31 are arranged in a V shape that is separated from each other from the inside to the outside in the radial direction along the shape of the pair of magnet insertion holes 31.

The permanent magnet 5 is, for example, a rare earth magnet. Examples of rare earth magnets include neodymium magnets, samarium-cobalt magnets, and placeodium magnets. In this embodiment, the permanent magnet 5 is a neodymium magnet. Neodymium magnets have the property that the residual magnetic flux density decreases as the temperature rises.
The magnetizing directions of the pair of permanent magnets 5 arranged in the pair of magnet insertion holes 31 are arranged so as to be the same in the radial direction. Further, the magnetizing directions of the pair of permanent magnets 5 adjacent to each other in the circumferential direction are arranged so as to be opposite to each other in the radial direction. In other words, the permanent magnets 5 are arranged so that the poles of each pair of permanent magnets 5 arranged in a V shape are alternately different.

The portion of the magnet insertion hole 31 in which the permanent magnet 5 is not inserted is a gap S. This gap S functions as a flux barrier. With the permanent magnet 5 inserted in the magnet insertion hole 31, a resin material (not shown) is filled and fixed between the permanent magnet 5 and the rotor core 4.

(Temperature sensitive member)
FIG. 3 is an exploded perspective view of the rotor core 4 and the temperature sensitive member 6 according to the first embodiment.
As shown in FIGS. 2 and 3, the temperature sensitive member 6 is inserted into the temperature sensitive member insertion hole 32 of the rotor core 4 from the axial direction. Therefore, the temperature sensitive member 6 is arranged between the pair of permanent magnets 5 adjacent to each other in the circumferential direction. The temperature sensitive member 6 is provided on a magnetic circuit parallel to the pair of permanent magnets 5. The temperature sensitive member 6 is formed in a rectangular shape with chamfered corners when viewed from the axial direction. The temperature sensitive member 6 extends along the axial direction.
The temperature sensitive member 6 is arranged on the d-axis of the rotor 3 when viewed from the axial direction. The temperature sensitive member 6 is arranged symmetrically with respect to the d-axis of the rotor 3 when viewed from the axial direction.

FIG. 4 is a graph showing the relationship between the temperature T and the saturation magnetic flux density Bs in the temperature sensitive member 6 according to the first embodiment. The horizontal axis of FIG. 4 represents the temperature T of the temperature sensitive member 6. The vertical axis of FIG. 4 represents the saturation magnetic flux density Bs of the temperature sensitive member 6 at each temperature T.
The temperature sensitive member 6 is made of a material whose saturation magnetic flux density Bs changes with temperature T. Specifically, as shown in FIG. 4, the temperature-sensitive member 6 has a saturation magnetic flux density Bs that decreases as the temperature T increases. In the present embodiment, the temperature sensitive member 6 is a soft magnetic material such as soft ferrite or an iron-nickel alloy that changes from a paramagnetic material to a non-magnetic material when the Curie temperature is reached.

FIG. 5 is an explanatory diagram showing the distribution of the magnetic flux density B at a low temperature (temperature T1 in FIG. 4) of the rotary electric machine 1 according to the first embodiment. FIG. 6 is an explanatory diagram showing the distribution of the magnetic flux density B at a high temperature (temperature T2 in FIG. 4) of the rotary electric machine 1 according to the first embodiment.
As shown in FIG. 5, at low temperatures, the saturation magnetic flux density Bs of the temperature-sensitive member 6 increases, so that the magnetic flux of the permanent magnet 5 passes through the temperature-sensitive member 6 and leaks. As a result, at low temperatures, the magnetic force of the permanent magnet 5 of the rotor 3 is weakened.
As shown in FIG. 6, since the saturation magnetic flux density Bs of the temperature sensitive member 6 becomes small at a high temperature, the magnetic flux of the permanent magnet 5 is less likely to pass through the temperature sensitive member 6 than at a low temperature. Therefore, a magnetic circuit in which magnetic flux does not easily leak is formed through the temperature sensitive member 6. Therefore, when the temperature is high, the magnetic flux is less likely to leak in the rotor 3, so that the magnetic force of the permanent magnet 5 is strengthened in the rotor 3.

(End face plate)
Returning to FIG. 1, the end face plate 7 covers the rotor core 4 from both sides in the axial direction. A pair of end face plates 7 are provided at both ends of the rotor core 4 in the axial direction. The pair of end face plates 7 are arranged in contact with the end faces of the rotor core 4 facing in the axial direction. The end face plate 7 is formed in an annular shape centered on the axis C. The outer diameter of the end face plate 7 is substantially the same as the outer diameter of the rotor core 4. The inner diameter of the end face plate 7 is substantially the same as the inner diameter of the rotor core 4 (inner diameter of the shaft insertion hole 33). The end face plate 7 is fixed to the rotor core 4 by, for example, caulking or fastening. The end face plate 7 suppresses the movement of the permanent magnet 5 and the temperature sensitive member 6 in the axial direction.
The end face plate 7 may have, for example, a flow path for flowing a refrigerant along the radial direction. In this case, the flow path may be provided between the end face plate 7 and the rotor core 4 by forming a groove on the end face of the end face plate 7 facing the rotor core 4 side in the axial direction. Further, the end face plate 7 may be adhesively fixed to the rotor core 4.

(Action, effect)
Next, the actions and effects of the rotor 3 and the rotary electric machine 1 described above will be described.
FIG. 7 is a graph showing a counter electromotive voltage waveform of the rotary electric machine 1 according to the first embodiment when no load is applied. The horizontal axis of FIG. 7 represents time, and the vertical axis represents the counter electromotive voltage for each time. The waveform G1 in FIG. 7 shows a counter electromotive voltage waveform when the temperature T of the rotor 3 in the present embodiment is 100 ° C. Waveform G2 shows a counter electromotive voltage waveform when the temperature T of the rotor 3 in this embodiment is −20 ° C. The waveform G3 shows a counter electromotive voltage waveform when the temperature T of the rotor 3 in the prior art without the temperature sensitive member 6 is −20 ° C.

Here, in the permanent magnet 5, the residual magnetic flux density B (magnetic force) is strengthened as the temperature decreases. Therefore, under low temperature conditions, the counter electromotive voltage due to the permanent magnet 5 tends to be larger than at high temperatures. As shown in FIG. 7, the counter electromotive voltage waveform G3 of the prior art which does not have the temperature sensitive member 6 has a larger value (amplitude) of the counter electromotive voltage than the counter electromotive voltage waveform G1 at high temperature. Therefore, in the prior art, it is necessary to design the semiconductor element of the inverter so that the counter electromotive voltage at low temperature is equal to or less than the withstand voltage of the rotary electric machine 1. On the other hand, the counter electromotive voltage waveform G2 of the rotor 3 of the present embodiment at a low temperature has a value equivalent to that of the counter electromotive voltage waveform G1 at a high temperature.

According to the rotor 3 of the present embodiment, the temperature sensitive member 6 is arranged between the permanent magnets 5 adjacent to each other in the circumferential direction, and the saturation magnetic flux density Bs of the temperature sensitive member 6 decreases as the temperature T rises. .. At low temperatures, the saturation magnetic flux density Bs of the temperature sensitive member 6 is relatively large. Therefore, when the magnetic flux passes through the temperature sensitive member 6, magnetic flux leakage from the permanent magnet 5 is likely to occur. As a result, the counter electromotive voltage generated in the rotor 3 can be reduced. Therefore, under low temperature conditions, the counter electromotive voltage can be lowered as compared with the conventional technique that does not have the temperature sensitive member 6, so that the withstand voltage of the semiconductor element used in the inverter can be lowered. In particular, since the back electromotive voltage can be withstood even when the grade of the semiconductor element in the inverter is lowered as compared with the conventional technique, a cheaper semiconductor element can be used.
On the other hand, when the rotary electric machine 1 is driven and the temperature T rises due to internal heat generation, the saturation magnetic flux density Bs of the temperature sensitive member 6 is smaller than when the temperature is low. Therefore, by suppressing the passage of magnetic flux through the temperature sensitive member 6, magnetic flux leakage from the permanent magnet 5 is less likely to occur. As a result, under high temperature conditions, the magnetic force along the radial direction of the permanent magnet 5 can be increased, and the torque of the rotor 3 can be improved. Therefore, a desired torque can be output when the rotary electric machine 1 is driven.
Therefore, it is possible to provide the rotor 3 which can weaken the magnetic force at low temperature and increase the magnetic force at high temperature.

As shown in FIG. 2, a rib 35 is provided between the temperature-sensitive member insertion hole 32 and the magnet insertion hole 31, and the corner portion of the temperature-sensitive member insertion hole 32 is chamfered when viewed from the axial direction. There is. Therefore, since the corners are not formed on the rib 35, for example, when the rotor 3 rotates, it is possible to suppress the concentration of stress on the rib 35 due to the centrifugal force of the permanent magnet 5 and the temperature sensitive member 6. Therefore, the rotor 3 can withstand centrifugal force and can reliably hold the temperature sensitive member 6.

The temperature sensitive member 6 is a soft magnetic material. Therefore, the temperature sensitive member 6 itself does not generate magnetic flux, but is magnetized by the magnetic force of the permanent magnet 5 arranged in the vicinity of the temperature sensitive member 6. Therefore, the saturation magnetic flux density Bs of the temperature sensitive member 6 changes according to the temperature T, so that a desired magnetic path corresponding to the temperature T can be formed. Therefore, it is possible to effectively weaken the magnetic force at low temperature and increase the magnetic force at high temperature.

As shown in FIG. 1, the temperature sensitive member 6 is arranged symmetrically with respect to the d-axis of the rotor 3 when viewed from the axial direction. Thereby, the magnetic force of the permanent magnet 5 can be adjusted more effectively. Specifically, when the temperature is low, the leakage flux is generated by allowing the magnetic flux to pass through the temperature sensitive member 6, and when the temperature is high, the magnetic force in the radial direction is increased by suppressing the passage of the magnetic flux through the temperature sensitive member 6. Therefore, the magnetic force can be remarkably changed according to the temperature T.

The rotor 3 includes an end face plate 7 arranged at the axial end of the rotor core 4. The end face plate 7 can limit the axial movement of the permanent magnet 5 and the temperature sensitive member 6. Further, for example, the refrigerant may be supplied along the radial direction of the rotor 3 via the end face plate 7. In this case, since the temperature T of the rotor 3 can be positively cooled by using the refrigerant, it is easy to adjust the temperature T of the rotor 3. Therefore, by setting the desired temperature T, the saturation magnetic flux density Bs of the temperature sensitive member 6 can be set to a desired value.

According to the rotary electric machine 1 of the present embodiment, the rotor 3 and the stator 2 described above are provided. As a result, by weakening the magnetic force at low temperature, it is possible to use an inexpensive semiconductor element with a low withstand voltage in the inverter, and at the same time, a high-performance rotary electric machine 1 using a rotor 3 whose torque is improved by increasing the magnetic force at high temperature can be obtained. Can be provided.

(Second Embodiment)
Next, the second embodiment of the present invention will be described. FIG. 8 is a partial front view of the rotary electric machine 1 according to the second embodiment. In the following description, the same components as those in the first embodiment described above will be designated by the same reference numerals, and the description thereof will be omitted as appropriate. In the second embodiment, the arrangement and number of the permanent magnets 5 and the temperature sensitive member 6 are different from those in the above-described embodiment.

In the present embodiment, the rotor core 4 further has one central magnet insertion hole 231 between the pair of magnet insertion holes 31. The central magnet insertion hole 231 extends in a direction orthogonal to a straight line L (d-axis) that passes through the axis C and is along the radial direction when viewed from the axial direction. The pair of magnet insertion holes 31 and the central magnet insertion hole 231 are arranged in a V shape. A permanent magnet 5 is inserted into the pair of magnet insertion holes 31 and the central magnet insertion hole 231. Further, in the rotor core 4, a temperature sensitive member insertion hole 32 is provided between the central magnet insertion hole 231 and each magnet insertion hole 31. A temperature sensitive member 6 is inserted into each temperature sensitive member insertion hole 32. In the present embodiment, the temperature sensitive members 6 are provided at positions separated from the d-axis in the circumferential direction and on both sides of the d-axis. The temperature sensitive member 6 is inclined so as to approach the d-axis side from the inside to the outside in the radial direction when viewed from the axial direction.

According to the present embodiment, it is applied to the rotor 3 in which one pole is formed by three permanent magnets 5 (a pair of permanent magnets 31 and a permanent magnet 5 inserted into the central magnet insertion hole 231). However, the same actions and effects as those of the above-described first embodiment can be obtained. Therefore, the versatility of the rotor 3 can be improved.

(Third Embodiment)
Next, a third embodiment of the present invention will be described. FIG. 9 is a partial front view of the rotary electric machine 1 according to the third embodiment. In the following description, the same components as those in the first embodiment described above will be designated by the same reference numerals, and the description thereof will be omitted as appropriate. The third embodiment is different from the above-described embodiment in that the permanent magnet 5 and the temperature sensitive member 6 are inserted into one magnet insertion hole 31.

In this embodiment, the rotor core 4 has one magnet insertion hole 331 for one pole of the rotor 3. The magnet insertion hole 331 is formed in a U shape that opens outward in the radial direction when viewed from the axial direction. A permanent magnet 5 and a temperature sensitive member 6 are inserted into the magnet insertion hole 331. A pair of permanent magnets 5 are arranged at both ends of the magnet insertion hole 331 in the longitudinal direction. The temperature sensitive member 6 is arranged between the pair of permanent magnets 5. Further, the rotor core 4 has a plurality of protrusions protruding from the inner wall of the magnet insertion hole 331 toward the inside of the magnet insertion hole 331. Specifically, the protrusion has a magnet locking protrusion 336 and a temperature sensitive member locking protrusion 337.

The magnet locking projection 336 protrudes outward in the radial direction from the inner wall of the magnet insertion hole 331 located inside in the radial direction. Magnet locking protrusions 336 are provided on both sides of the magnet insertion hole 331 in the longitudinal direction for each permanent magnet 5. The magnet locking projection 336 suppresses the permanent magnet 5 from moving in the longitudinal direction of the magnet insertion hole 331.
The temperature-sensitive member locking projection 337 projects radially outward from the inner wall of the magnet insertion hole 331 located inside in the radial direction. The temperature-sensitive member locking protrusions 337 are provided on both sides of the magnet insertion hole 331 in the longitudinal direction (circumferential direction) with respect to the temperature-sensitive member 6. The temperature-sensitive member locking projection 337 suppresses the temperature-sensitive member 6 from moving in the longitudinal direction of the magnet insertion hole 331.

According to this embodiment, the rotor 3 can be formed without providing the rib 35 (see FIG. 1) between the permanent magnet 5 and the temperature sensitive member 6. Therefore, the permanent magnet 5 and the temperature sensitive member 6 can be arranged at a desired position without considering the stress acting on the rib 35 and the like. Further, the rotor 3 can have a simple structure as compared with the case where the magnet insertion hole 31 and the temperature sensitive member insertion hole 32 are provided respectively.

The technical scope of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.
In the above-described embodiment, the configuration in which one pole of the rotor 3 is formed by two or three permanent magnets 5 has been described, but the present invention is not limited to this. For example, one pole of the rotor 3 may be formed by four or more permanent magnets 5. In this case, it is desirable to provide a temperature sensitive member 6 between the permanent magnets 5. Further, for example, one pole of the rotor 3 may be formed by one permanent magnet 5 extending orthogonally in the radial direction. In this case, the temperature sensitive member 6 may be arranged between the permanent magnets 5 having different poles adjacent to each other in the circumferential direction. Similarly, for example, in the first embodiment, the temperature sensitive member 6 may be arranged outside the pair of permanent magnets 5 in the circumferential direction. In this case, it is desirable that the temperature sensitive member 6 is arranged on a parallel magnetic circuit of a pair of magnets.

The end face plate 7 may not be provided. In this case, for example, the temperature sensitive member 6 may be fixed to the rotor core 4 with epoxy or caulking.
The shape of the temperature sensitive member 6 when viewed from the axial direction is not limited to the above-described embodiment. For example, the temperature sensitive member 6 may be formed in a rectangular shape in which the corners are not chamfered when viewed from the axial direction.

In addition, it is possible to replace the constituent elements in the above-described embodiment with well-known constituent elements as appropriate without departing from the spirit of the present invention, and the above-described embodiments and modifications may be appropriately combined.

1 Rotating electric machine 2 Stator 3 Rotor 4 Rotor core 5 Permanent magnet 6 Temperature sensitive member 7 End face plate 31,231,331 Magnet insertion hole 32 Temperature sensitive member insertion hole 35 Rib

Claims (6)

A rotor core that is formed in an annular shape and has a magnet insertion hole that extends in the axial direction.
A plurality of permanent magnets inserted into the magnet insertion holes and provided along the circumferential direction of the rotor core, and
A temperature-sensitive member that is arranged between the permanent magnets adjacent to each other in the circumferential direction, extends along the axial direction, and the saturation magnetic flux density decreases as the temperature rises.
A rotor characterized by being equipped with. The rotor core has a temperature-sensitive member insertion hole into which the temperature-sensitive member is inserted.
A rib is provided between the temperature-sensitive member insertion hole and the magnet insertion hole.
The rotor according to claim 1, wherein the corner portion of the temperature-sensitive member insertion hole is chamfered when viewed from the axial direction. The rotor according to claim 1 or 2, wherein the temperature-sensitive member is a soft magnetic material. The rotor according to any one of claims 1 to 3, wherein the temperature-sensitive member is arranged symmetrically with respect to the d-axis of the rotor when viewed from the axial direction. The rotor according to any one of claims 1 to 4, further comprising an end face plate arranged at the axial end of the rotor core. The rotor according to any one of claims 1 to 5,
A stator arranged with a gap on the outer side in the radial direction of the rotor,
A rotary electric machine characterized by being equipped with.

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