JP2020198682A - Rotor - Google Patents

Abstract

To suppress magnetic flux leakage to a shaft from a magnetic material.SOLUTION: A rotor 20 comprises a cylindrical material 21, a permanent magnet 31, two shafts 41, 51 and an adhesive layer 61. The permanent magnet 31 is arranged in the cylindrical material 21. The two shafts 41, 51 are inserted into the cylindrical material 21. The permanent magnet 31 and the two shafts 41, 51 are arranged in parallel with an axial direction of the cylindrical material 21. An insulative adhesive layer 61 is provided between the permanent magnet 31 and the shafts 41 and 51.SELECTED DRAWING: Figure 1

Description

The present invention relates to a rotor.

The rotary electric machine described in Patent Document 1 includes a stator and a rotor. The stator includes a stator core and a coil. The rotor includes a tubular member, a magnetic material press-fitted into the tubular member, and a shaft press-fitted into the tubular member. The magnetic material rotates due to the rotating magnetic field caused by the current flowing through the coil. As the magnetic material rotates, the tubular member and the shaft rotate together.

Japanese Unexamined Patent Publication No. 2008-295214

In the rotary electric machine of Patent Document 1, the magnetic material and the shaft are in contact with each other, and magnetic flux leakage may occur from the magnetic material to the shaft. When the magnetic flux leaks from the magnetic material to the shaft, the magnetic flux interlinking with the stator is reduced, which causes the output of the rotary electric machine to decrease.

An object of the present invention is to provide a rotor capable of suppressing magnetic flux leakage from a magnetic material to a shaft.

The rotor for solving the above problems includes a tubular member, a magnetic material arranged in the tubular member, and a shaft inserted into the tubular member and arranged side by side with the magnetic material in the axial direction of the tubular member. And an insulating adhesive layer provided between the magnetic material and the shaft and adhering the magnetic material and the shaft.

The shaft is separated from the magnetic material by interposing an adhesive layer between the shaft and the magnetic material. Therefore, it is possible to suppress magnetic flux leakage from the magnetic material to the shaft as compared with the case where the magnetic material and the shaft are in contact with each other.

Regarding the rotor, a non-conductive filler may be dispersed in the adhesive layer.
By dispersing the filler, various functions can be imparted to the adhesive layer depending on the type of the filler.

For the rotor, the shaft may be inserted into each of both ends in the axial direction of the tubular member.
For the rotor, the shaft may be press-fitted into the tubular member.

If an adhesive is provided between the shaft and the tubular member and an attempt is made to fix the shaft and the tubular member by bonding with the adhesive, a region for filling the adhesive is required between the shaft and the tubular member. .. If there is a region for filling the adhesive between the shaft and the tubular member, it causes the central axis of the shaft to deviate from the central axis of the tubular member during bonding. On the other hand, by fixing the shaft to the tubular member by press fitting, the deviation between the central axis of the shaft and the central axis of the tubular member can be reduced as compared with the case where the shaft and the tubular member are fixed by adhesion. ..

According to the present invention, it is possible to suppress magnetic flux leakage from the magnetic material to the shaft.

The schematic block diagram which shows the air conditioner for a vehicle and the rotary electric machine used for the air conditioner for a vehicle. Sectional view of the rotor.

Hereinafter, an embodiment of the rotor will be described.
As shown in FIG. 1, the vehicle air conditioner 100 includes an electric compressor 101 and an external refrigerant circuit 102. The electric compressor 101 includes a tubular housing 103, a rotary electric machine 10 housed in the housing 103, and a compression unit 104 that compresses the refrigerant. The housing 103 includes a supply port 110 to which a refrigerant is supplied and a discharge port 111 for discharging the compressed refrigerant. The supply port 110 is a hole that opens into the accommodation area S in which the rotary electric machine 10 is accommodated. The compression unit 104 compresses the refrigerant by the rotational force generated by driving the rotary electric machine 10, and discharges the refrigerant from the discharge port 111. An external refrigerant circuit 102 is connected to the supply port 110 and the discharge port 111. The external refrigerant circuit 102 includes, for example, a heat exchanger and an expansion valve. The vehicle air conditioner 100 heats and cools the inside of the vehicle by compressing the refrigerant by the electric compressor 101 and heat exchange and expansion of the refrigerant by the external refrigerant circuit 102. As the compression unit 104, any type of compression unit such as a scroll type, a piston type, and a vane type can be used.

The rotary electric machine 10 includes a stator 11, a rotor 20, and a bearing 14 that supports the rotor 20 in a rotatable state. The stator 11 includes a cylindrical stator core 12 and a coil 13 wound around the stator core 12. The stator core 12 is fixed to the inner peripheral surface of the housing 103.

As shown in FIGS. 1 and 2, the rotor 20 includes a tubular member 21, a permanent magnet 31 which is a magnetic material, two shafts 41 and 51, and an adhesive layer 61. The tubular member 21 has a cylindrical shape in which the axis of the tubular member 21 extends linearly. The tubular member 21 can be made of, for example, a fiber reinforced material such as carbon fiber reinforced plastic, or various elastically deformable materials such as titanium alloy and Inconel.

The permanent magnet 31 has a solid columnar shape. The permanent magnet 31 is magnetized in the radial direction of the permanent magnet 31. The axial dimension of the permanent magnet 31 is shorter than the axial dimension of the tubular member 21. As the permanent magnet 31, various magnets such as a ferrite magnet, a neodymium magnet, and a samarium-cobalt magnet can be used. One of both end faces 32 and 33 in the axial direction of the permanent magnet 31 is designated as the first end face 32, and the end face 33 different from the first end face 32 is referred to as the second end face 33.

The permanent magnet 31 is arranged in the tubular member 21. The permanent magnet 31 and the tubular member 21 are arranged concentrically. That is, the central axis C1 of the permanent magnet 31 coincides with the central axis of the tubular member 21. The state in which the central axis C1 of the permanent magnet 31 and the central axis of the tubular member 21 coincide with each other allows an error due to a tolerance or the like, and the central axis C1 of the permanent magnet 31 and the tubular member 21 are allowed. There may be a slight deviation in the central axis of 21.

The permanent magnet 31 is arranged between both ends 22 and 23 in the axial direction of the tubular member 21. The permanent magnet 31 is fixed to the tubular member 21 by being press-fitted into the tubular member 21. In the state where the permanent magnet 31 is not inserted into the tubular member 21, the inner diameter of the tubular member 21 is smaller than the diameter of the permanent magnet 31. When the permanent magnet 31 is press-fitted into the tubular member 21, the tubular member 21 exerts an elastic force on the permanent magnet 31 to apply a tightening force toward the inside of the tubular member 21 in the radial direction. Due to this tightening force, a frictional force is generated at the interface between the outer peripheral surface of the permanent magnet 31 and the inner peripheral surface of the tubular member 21.

One of the two shafts 41 and 51 is referred to as a first shaft 41, and a shaft 51 different from the first shaft 41 is referred to as a second shaft 51. The first shaft 41 includes a columnar shaft main body 42 and a flange portion 43 protruding outward in the radial direction of the shaft main body 42 from the outer peripheral surface of the shaft main body 42. One end side of the shaft body 42 in the axial direction with respect to the flange portion 43 is a press-fitting portion 44 that is press-fitted into the tubular member 21. The second shaft 51 includes a columnar shaft main body 52 and a flange portion 53 protruding outward in the radial direction of the shaft main body 52 from the outer peripheral surface of the shaft main body 52. One end side of the shaft body 52 in the axial direction with respect to the flange portion 53 is a press-fitting portion 54 that is press-fitted into the tubular member 21. The diameters of the press-fitting portions 44 and 54 of the two shafts 41 and 51 are the same. The shafts 41 and 51 are made of a metal such as iron or an alloy of iron.

Assuming that one of both end portions 22 and 23 of the tubular member 21 is the first end portion 22 and the end portion different from the first end portion 22 is the second end portion 23, the first shaft 41 is inserted into the first end portion 22. Has been done. More specifically, the press-fitting portion 44 of the first shaft 41 is inserted into the first end portion 22 of the tubular member 21. The central axis C2 of the first shaft 41 coincides with the central axis of the tubular member 21. The press-fitting portion 44 of the first shaft 41 is arranged inside the tubular member 21, and a portion of the first shaft 41 different from the press-fitting portion 44 projects outside the tubular member 21. The end face 45 of the press-fitting portion 44 is separated from the first end face 32 on the first shaft 41 side of the end faces 32 and 33 of the permanent magnet 31. The second shaft 51 is inserted into the second end 23. More specifically, the press-fitting portion 54 of the second shaft 51 is inserted into the second end portion 23 of the tubular member 21. The central axis C3 of the second shaft 51 coincides with the central axis of the tubular member 21. The first shaft 41, the second shaft 51, and the permanent magnet 31 are arranged side by side in the axial direction of the tubular member 21 so that the central axes C1, C2, and C3 are located on the same straight line. The state where the central axes C1, C2, and C3 are located on the same straight line allows an error due to a tolerance or the like, and the positions of the central axes C1, C2, and C3 are slightly deviated from each other. May be good. The press-fitting portion 54 of the second shaft 51 is arranged inside the tubular member 21, and a portion of the second shaft 51 different from the press-fitting portion 54 projects outside the tubular member 21. The end face 55 of the press-fitting portion 54 is separated from the second end face 33 on the second shaft 51 side of the end faces 32 and 33 of the permanent magnet 31.

In the present embodiment, the shafts 41 and 51 are fixed to the tubular member 21 by being press-fitted into the tubular member 21. With the shafts 41 and 51 not inserted into the tubular member 21, the inner diameter of the tubular member 21 is smaller than the diameter of the press-fitting portions 44 and 54. When the press-fitting portions 44, 54 of the shafts 41, 51 are press-fitted into the tubular member 21, the tubular member 21 exerts an elastic force to tighten the tubular member 21 inward in the radial direction. Is acting on. Due to this tightening force, a frictional force is generated at the interface between the outer peripheral surfaces of the press-fitting portions 44 and 54 and the inner peripheral surface of the tubular member 21.

An insulating adhesive is provided between the first end surface 32 of the permanent magnet 31 and the end surface 45 of the first shaft 41, and between the second end surface 33 of the permanent magnet 31 and the end surface 55 of the second shaft 51, respectively. A layer 61 is provided. The adhesive layer 61 adheres the permanent magnet 31 and the shafts 41 and 51. As the adhesive layer 61, one obtained by curing an adhesive having excellent heat resistance and heat dissipation is preferable, and one in which the filler 62 is dispersed is used. The adhesive layer 61 is obtained by curing a thermosetting resin such as an epoxy resin or a silicone resin. The filler 62 is made of a non-conductive material. Various fillers 62 can be used depending on the purpose of reinforcing the adhesive layer 61, improving the heat resistance of the adhesive layer 61, improving the thermal conductivity of the adhesive layer 61, and the like. For example, as the filler 62, glass, aramid, ceramic, silica, thermoplastic resin and the like can be used.

In the rotor 20 configured as described above, each of the shafts 41 and 51 is supported by bearings 14.
The operation of this embodiment will be described.

When an electric current is passed through the coil 13, the permanent magnet 31 rotates. As the permanent magnet 31 rotates, the tubular member 21 and the shafts 41 and 51 rotate together. As a result, the rotary electric machine 10 is driven. When the rotary electric machine 10 is driven, the refrigerant is supplied to the compression unit 104 through the accommodation area S in which the rotary electric machine 10 is housed.

An adhesive layer 61 is interposed between the shafts 41 and 51 and the permanent magnet 31. By providing the adhesive layer 61, the shafts 41 and 51 are separated from the permanent magnet 31. Compared with the case where the permanent magnet 31 and the shafts 41 and 51 are in contact with each other, it is possible to suppress magnetic flux leakage from the permanent magnet 31 to the shafts 41 and 51.

In order to suppress the contact between the permanent magnet 31 and the shafts 41 and 51, it is conceivable to interpose a space between the permanent magnet 31 and the shafts 41 and 51. However, in this case, the torque generated by the rotation of the permanent magnet 31 is transmitted to the shafts 41 and 51 only through the tubular member 21, and the torsional stress acting on the tubular member 21 becomes large.

On the other hand, by interposing the adhesive layer 61 between the permanent magnet 31 and the shafts 41 and 51 as in the present embodiment, the torque generated by the rotation of the permanent magnet 31 is transferred to the shaft via the tubular member 21. In addition to being transmitted to 41, 51, it is transmitted to shafts 41, 51 via the adhesive layer 61. That is, the torque due to the rotation of the permanent magnet 31 is dispersed in the tubular member 21 and the adhesive layer 61 and transmitted to the shafts 41 and 51. The torque transmitted to the shafts 41 and 51 via the tubular member 21 can be reduced as compared with the case where the torque is transmitted to the shafts 41 and 51 only by the tubular member 21. As a result, the torsional stress acting on the tubular member 21 can be reduced. Further, if the frictional force at the interface between the permanent magnet 31 and the tubular member 21 does not exceed the torque transmitted from the permanent magnet 31 to the tubular member 21, the permanent magnet 31 and the tubular member 21 slip. By reducing the torque transmitted from the permanent magnet 31 to the tubular member 21, it is possible to prevent the permanent magnet 31 and the tubular member 21 from slipping. Similarly, if the frictional force at the interface between the shafts 41, 51 and the cylinder member 21 does not exceed the torque transmitted from the cylinder member 21 to the shafts 41, 51, the shafts 41, 51 and the cylinder member 21 Slip. By reducing the torque transmitted from the tubular member 21 to the shafts 41 and 51, slip between the shafts 41 and 51 and the tubular member 21 can be suppressed.

Further, when a space is interposed between the permanent magnet 31 and the shafts 41 and 51, the refrigerant may enter the space, which causes electrolytic corrosion in the permanent magnet 31 and the shafts 41 and 51. By forming the adhesive layer 61 between the permanent magnet 31 and the shafts 41 and 51, it is possible to prevent the refrigerant from entering between the permanent magnet 31 and the shafts 41 and 51, and the permanent magnet 31 and the shafts 41 and 51 Electrolytic corrosion is suppressed.

Further, when a space is interposed between the permanent magnet 31 and the shafts 41 and 51, it is difficult for heat to be conducted from the permanent magnet 31 to the shafts 41 and 51. When the rotary electric machine 10 is driven, the permanent magnet 31 generates heat due to the eddy current. Since the permanent magnet 31 is covered with the tubular member 21, it is difficult for heat to be dissipated, and heat tends to be trapped. By interposing the adhesive layer 61 between the permanent magnet 31 and the shafts 41 and 51, the shafts 41 and 51 are heated as compared with the case where a space is interposed between the permanent magnet 31 and the shafts 41 and 51. Is easy to conduct. Therefore, heat dissipation of the permanent magnet 31 is likely to occur.

The effect of this embodiment will be described.
(1) By interposing the adhesive layer 61 between the permanent magnet 31 and the shafts 41 and 51, the permanent magnet 31 to the shaft 41 are compared with the case where the permanent magnet 31 and the shafts 41 and 51 are in contact with each other. , 51 can suppress magnetic flux leakage. By suppressing the magnetic flux leakage from the permanent magnet 31 to the shafts 41 and 51, the magnetic flux interlinking with the stator 11 can be reduced, and the output of the rotary electric machine 10 can be suppressed from dropping.

(2) By interposing the adhesive layer 61 between the permanent magnet 31 and the shafts 41 and 51, it acts on the tubular member 21 as compared with the case where a space is interposed between the permanent magnet 31 and the shafts 41 and 51. The torsional stress to be generated can be reduced. Breakage of the tubular member 21 due to torsional stress can be suppressed, and the life of the tubular member 21 can be extended.

(3) By interposing the adhesive layer 61 between the permanent magnet 31 and the shafts 41 and 51, the permanent magnet 31 has a space as compared with the case where a space is interposed between the permanent magnet 31 and the shafts 41 and 51. The temperature does not rise easily. Thermal demagnetization due to an increase in the temperature of the permanent magnet 31 can be suppressed.

(4) When the permanent magnet 31 and the shafts 41 and 51 are in contact with each other, the permanent magnet 31 and the shaft 41 are caused by the difference between the linear expansion coefficient of the permanent magnet 31 and the linear expansion coefficient of the shafts 41 and 51. , 51 is thermally expanded, stress is applied to the permanent magnets 31 and the shafts 41 and 51. When stress is applied to the permanent magnets 31 and the shafts 41 and 51, it causes breakage of the permanent magnets 31 and misalignment of the shafts 41 and 51. By providing the adhesive layer 61 so that the thermal expansion of the permanent magnet 31 and the thermal expansion of the shafts 41 and 51 are absorbed by the adhesive layer 61, stress is applied to the permanent magnet 31 and the shafts 41 and 51. Can be suppressed.

(5) The filler 62 is dispersed in the adhesive layer 61. By dispersing the filler 62 having the characteristics according to the purpose in the adhesive layer 61, various functions can be imparted to the adhesive layer 61.

(6) The shafts 41 and 51 are press-fitted into the tubular member 21. When an adhesive is provided between the shafts 41, 51 and the tubular member 21 and the shafts 41, 51 and the tubular member 21 are fixed by adhesion with the adhesive, the adhesive is adhered between the shafts 41, 51 and the tubular member 21. An area is needed to fill the agent. When there is a region for filling the adhesive between the shafts 41 and 51 and the tubular member 21, the shafts 41 and 51 can move in the radial direction within the region when the adhesive is not cured. .. Therefore, when the shafts 41 and 51 and the tubular member 21 are fixed with an adhesive, the central axes C2 and C3 of the shafts 41 and 51 may be displaced from the central axis of the tubular member 21 at the time of bonding. On the other hand, by fixing the shafts 41 and 51 to the tubular member 21 by press fitting, the central axes C2 and C3 of the shafts 41 and 51 and the cylinder are compared with the case where the shafts 41 and 51 are fixed to the tubular member 21 by adhesion. The deviation of the member 21 from the central axis can be reduced. Further, when the two shafts 41 and 51 are fixed to the tubular member 21 as in the embodiment, the central axes C2 and C3 of the two shafts 41 and 51 are likely to be located on the same straight line.

(7) By adhering the permanent magnet 31 and the shafts 41 and 51 with the adhesive layer 61, the rigidity of the tubular member 21 in the rotor 20 in the bending direction with respect to the axial direction is increased. Resonance is less likely to occur in the rotor 20, and the decrease in the resonance rotation speed of the rotary electric machine 10 is suppressed.

The embodiment can be modified and implemented as follows. The embodiments and the following modifications can be implemented in combination with each other to the extent that they are technically consistent.
○ The shafts 41 and 51 may be fixed to the tubular member 21 by an adhesive provided between the shafts 41 and 51 and the tubular member 21. In this case, the permanent magnet 31 may also be fixed to the tubular member 21 by an adhesive provided between the permanent magnet 31 and the tubular member 21. When the shafts 41 and 51 and the permanent magnet 31 are fixed to the tubular member 21 by an adhesive, torque due to the rotation of the permanent magnet 31 is transmitted to the shafts 41 and 51 via the adhesive. By providing the adhesive layer 61, the torsional stress acting on the adhesive for fixing the shafts 41, 51 and the permanent magnet 31 to the tubular member 21 can be reduced.

○ The number of shafts may be one, and the rotor 20 may include one of the first shaft 41 and the second shaft 51. Even in this case, the same effect as that of the embodiment can be obtained.

○ The filler 62 may not be dispersed in the adhesive layer 61.
The adhesive layer 61 may be formed of a material different from the thermosetting resin, as long as the permanent magnet 31 and the shafts 41 and 51 are adhered to each other.

○ The magnetic material is not limited to the permanent magnet 31, and may be, for example, a laminated core, an amorphous core, a dust core, or the like.
○ The permanent magnet 31 may be, for example, a solid square columnar shape, and the shape of the permanent magnet 31 is not particularly limited. Further, the shaft bodies 42 and 52 may be, for example, a square columnar shape, and the shapes of the shaft bodies 42 and 52 are not particularly limited. Then, for example, when the permanent magnet 31 has a solid square columnar shape and the shaft bodies 42 and 52 have a square columnar shape, the tubular member 21 needs to be formed in a square tubular shape. Therefore, the shape of the tubular member 21 may be appropriately changed depending on the shapes of the permanent magnet 31 and the shaft bodies 42 and 52.

○ The rotor 20 may be used in addition to the rotary electric machine 10 used in the vehicle air conditioner 100. For example, the rotor 20 may be used in the rotary electric machine 10 of the electric compressor that supplies air to the fuel cell. Further, the rotor 20 may be used for a rotary electric machine used other than the electric compressor.

20 ... rotor, 21 ... tubular member, 22 ... first end, 23 ... second end, 31 ... permanent magnet as magnetic material, 41, 51 ... shaft, 61 ... adhesive layer, 62 ... filler.

Claims (4)

Cylinder member and
The magnetic material arranged in the tubular member and
A shaft that is inserted into the tubular member and is arranged alongside the magnetic material in the axial direction of the tubular member.
A rotor provided between the magnetic material and the shaft, and comprising an insulating adhesive layer that adheres the magnetic material and the shaft. The rotor according to claim 1, wherein a non-conductive filler is dispersed in the adhesive layer. The rotor according to claim 1 or 2, wherein the shaft is inserted into each of both ends in the axial direction of the tubular member. The rotor according to any one of claims 1 to 3, wherein the shaft is press-fitted into the tubular member.