JP2003244894A - Liquid circulation cooling type rotating machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid circulation cooled type rotating machine that can be reduced in size as the rotating machine and carries sufficient cooling properties. <P>SOLUTION: In the liquid circulation cooled type rotating machine that performs cooling by circulating a cooling medium in the inside, the cooling medium is a low-viscosity inert liquid or water, and a copper wire 1, that constitutes a coil in the rotating machine, is coated with an FEP resin 3a having heat resistance, waterproof and insulating properties. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotating machine such as a liquid circulation cooling type electric motor.

[0002]

2. Description of the Related Art At present, rotary machines such as electric motors are strongly required to be miniaturized in order to save energy and resources.
Especially with the miniaturization of products that use rotating machines,
There is also a strong demand for miniaturization of rotating machines. However. Reducing the size of the rotating machine while maintaining the output of the rotating machine leads to a large coil current.

Here, the torque of the rotating machine is expressed by the following equation. T = 1 / √2 × IB (mω) (LD) cos θ
(T: torque, I: coil current, B: maximum magnetic flux density,
m: number of phases, ω: number of turns of one phase, L: coil length, D:
Rotor diameter, θ: Phase difference between I and B)

As can be seen from the above equation, if the rotor diameter D is left unchanged and only the coil length L is reduced to 1/2,
In order to make the generated torque T equivalent to the conventional one, it is necessary to double the coil current I. The Joule heat W generated by the coil current I is expressed by the following equation. W = I ² R (W:
Joule heat, R: copper loss)

As can be seen from the above equation, if the coil current I is doubled and the copper loss R is 1/2, the Joule heat W generated is doubled.

[0006] Therefore, when miniaturizing the rotating machine, high temperature of each part of the rotating machine including the coil becomes a problem. Therefore, heat resistance of components of the rotating machine and exhaust heat technology of the rotating machine are required. It becomes important.

The heat generated in the rotating machine includes Joule heat of the coil portion, heat due to iron loss of the stator and rotor, and frictional heat of the sliding portion. Of these, the coil has the highest temperature. The heat resistance of the coil insulation material greatly affects the performance of the rotating machine. The heat resistance of the insulating material is specified by the JIS standard (JIS-C4003), and the highest temperature insulating material exceeds 180 ° C. Polyimide is typical as an insulating material having high heat resistance. Many high heat resistant models have a structure in which a polyimide tape is wrapped around an enamel-treated coil.

The method for exhausting heat from the rotating machine is classified into an air cooling type, an oil cooling type and a water cooling type. Small output machines with low heat generation are often air-cooled using built-in fans, but medium and large output machines use liquid circulation cooling to circulate oil to exhaust heat and circulate oil to exhaust heat. A water-cooled type is used.

FIG. 4 is a schematic view of the structure of a conventional oil-cooled rotary machine. FIG. 4 shows a cross section in the direction along the axis of the rotor of the rotating machine.

As can be seen from FIG. 4, the oil-cooled rotary machine has a rotor 21 serving as a rotating shaft, a stator 22 arranged in a tubular shape around the rotor 21, and a stator 22 wound through the inside thereof. The coil 23 to be rotated and holding them inside,
It has a motor frame 24 serving as a housing. The motor frame 24 is provided with an oil supply port 25 for introducing oil serving as a refrigerant into the rotary machine and an oil discharge port 26 for discharging oil deprived of heat inside the rotary machine to the outside of the rotary machine.

In the oil-cooled rotary machine, the oil refrigerant cooled outside the rotary machine is supplied to the inside of the rotary machine from the oil supply port 25 of the rotary machine and directly contacts the rotor 21 and the stator 22 to rotate. It is a liquid circulation cooling type that takes away the heat inside the machine and discharges it to the outside. As the oil-refrigerant, lubricating oil, hydraulic oil, heat carrier oil, etc. that also serve as lubrication of each part are used.

A rotary machine that employs a liquid circulation cooling system like the oil-cooled rotary machine described above pours a refrigerant directly into the rotary machine.
The heat generated is removed by circulating this refrigerant with the external cooling device. The following properties are required for the refrigerant used in the cooling system. (1) High breakdown voltage, (2) High boiling point and flash point due to heat generation inside the rotating machine, (3) Low viscosity to avoid torque loss of rotating machine (4 ) No toxicity. There is hydraulic oil as an oil that applies to all of the above properties,
Hydraulic oil is excellent as a refrigerant used in a liquid circulation cooling type rotating machine.

However, even in the oil-cooled rotary machine using the hydraulic oil, when the size is further reduced, it is expected that the exhaust heat capacity will be insufficient due to the heat generated by the increase in the coil current. . If the exhaust heat capacity is insufficient, the heat resistance temperature of the insulating material of the coil will be exceeded, causing insulation deterioration, which not only lowers the output of the rotating machine, but may cause a short circuit accident.

FIG. 5 is a schematic view of the structure of a conventional water-cooled rotary machine. FIG. 5 shows a cross section in a direction along the axis of the rotor of the rotating machine.

As can be seen from FIG. 5, the water-cooled rotary machine has a rotor 31 as a rotary shaft, a stator 32 arranged in a tubular shape around the rotor 31, and a stator 32 wound through the inside thereof. The coil 33 to be
It has a motor frame 34 that serves as a housing. A plurality of water jackets 35 serving as water flow paths are provided inside the housing of the motor frame 34, and a water supply port 36 for introducing water serving as a refrigerant into each water jacket 35.
There is provided a water discharge port 37 for discharging the heat-removed water to the outside.

Unlike the oil-cooled rotary machine, the water-cooled rotary machine cannot directly cool the inside of the rotary machine with water. Therefore, a water jacket is provided inside the casing of the motor frame 34 arranged outside the rotary machine. 35, water is passed through the heat sink 35 to remove heat, and the heat is exhausted to the outside.

In a water-cooled rotary machine, the water serving as a refrigerant has a heat capacity twice as large as that of an oil refrigerant and a small viscosity (kinematic viscosity: 1 × 10 ⁻⁶ m ² / s (20 ° C.)). The exhaust heat capacity is high in terms of physical properties. However, in the water cooling type of water jacket structure, since the water jacket and the like are provided in the motor frame, the flow rate of the water refrigerant is much smaller than that of the oil cooling type that directly supplies the oil refrigerant into the rotating machine (see FIG. 4). Will end up. Therefore, the water-cooled type is different from the oil-cooled type.
Not as large as expected from the physical properties. Further, the water-cooled type not only complicates the casting of the motor frame, but also has to enlarge the outer shape by the amount of the water jacket, which makes it difficult to downsize the rotating machine.

Therefore, in order to satisfy both the further miniaturization and the improvement of the exhaust heat capacity, there may be considered a method of adopting a water cooling type of a structure in which a refrigerant is brought into direct contact with a rotor or a stator as in the oil cooling type. . In this method, compared to the water jacket type water cooling type, the rotor and stator are directly cooled, so that the water refrigerant can take heat efficiently and the flow passage cross section is large, so the flow rate of the refrigerant can be increased. can do. However, in this direct cooling water-cooled type, each part of the rotating machine is in direct contact with water, so that corrosion resistance is required. In particular, the water resistance of the insulating material of the coil is important, but the polyimide most used as the C-type insulating material is inferior in water resistance and cannot be used in this water-cooled type.

As the coil insulating layer having water resistance,
On the enamel coating of copper wire, PE (polyethylene) resin insulation layer, high degree of polymerization PVC (polyvinyl chloride)
With an insulating layer of the composition of JP-A-59-447.
No. 11) or a copper wire with an enamel coating on which an insulating layer of PP (polypropylene) resin is formed (see Japanese Patent Laid-Open No. 3-89413).

The water resistant wire is premised to be used in a normal temperature range. For example, in the case of a coil using PE resin, the temperature rise value is limited to 50 ° C. or less (JISB.
Therefore, the applicable rotating machines are limited to a part. Also, when using in high temperature range above room temperature,
Inferior long-term reliability.

FIG. 6 is a sectional view showing an example of a conventional waterproof copper wire. As shown in FIG. 6, the conventional water-resistant copper wire is a copper wire 41 that serves as a conducting wire for passing an electric current, an enamel layer 42 coated around the copper wire 41, and a polypropylene (coated around the enamel layer 42). PP) 43.

PP on the enamel coating shown in FIG.
Even if the wire with resin is used, the temperature is 100 ℃
The life is reported to be one year under the environment of 1), and it is clear that the life is further shortened in high temperature water. For this reason,
In a rotating machine that uses a water refrigerant for a long time in a high temperature range, an insulating layer of PE resin or PP resin cannot be used.

Further, fluorocarbon resin can be considered as the coil insulating layer having both water resistance and heat resistance. As an insulating layer using a fluororesin, an example in which a copper damage prevention material layer is applied on a conductor and ETFE (tetrafluoroethylene-ethylene copolymer) is coated thereon
21). As the copper damage prevention material layer, either an enamel baking coating layer or a tin plating layer is used to prevent the copper resin from accelerating the oxidation of the fluororesin and deteriorating it. However, the heat resistance of ETFE is 150 ° C.
And has class B insulation.

[0024]

On the market, there is a demand for a more compact rotating machine while maintaining the current characteristics. Therefore, when the length of the rotating machine is simply halved, the torque is also halved. If the input current is doubled to compensate for this, the amount of heat generated will be double that of the original rotating machine. Here, there is a portion where the temperature reaches 150 ° C. although it is local inside the conventional rotating machine. If the heat is doubled, the heat is concentrated at 300 ℃
The temperature rises close to the point, and thermal runaway occurs, exceeding the flash point (190 ° C) of the oil refrigerant used in conventional rotating machines. Also, with this heat generation, electrical insulation of the rotating machine (C class insulation)
Can not hold.

Therefore, an attempt was made to simply improve the cooling capacity by increasing the flow rate of the oil refrigerant, but the viscosity of the oil refrigerant is too high, and the torque loss increases, and the current characteristics of the rotating machine cannot be maintained. It was Furthermore, the auxiliary machine power (pump in the external cooling device) has also increased. Therefore, it is not possible to downsize the liquid circulation cooling type rotating machine by using the conventional oil refrigerant.

Further, in a liquid circulation cooling type rotary machine using a water refrigerant, ET is used as a coil insulating material having water resistance and heat resistance.
Although FE resin is used, the heat resistance of ETFE is 150.
Insulation of type B at ℃, and when promoting miniaturization of high-power rotating machines, the Joule heat increases due to the increase in current. Therefore, class C is required as heat resistance, which is insufficient.

In view of the above problems, the present invention provides a liquid circulation cooling type rotating machine which can be downsized and has sufficient cooling performance.

[0028]

A liquid circulation cooling type rotary machine according to the present invention which solves the above problems is a liquid circulation cooling type rotary machine which circulates a refrigerant inside to cool the same. It is characterized in that it is an active liquid.

The liquid circulation cooling type rotary machine according to the present invention for solving the above-mentioned problems is characterized in that the low-viscosity inert liquid is a fluorine-based heat carrier oil.

The liquid circulation cooling type rotary machine according to the present invention for solving the above-mentioned problems is characterized in that the low viscosity inert liquid is a fluorine-based inert liquid.

A liquid circulation cooling type rotary machine according to the present invention which solves the above-mentioned problems is a liquid circulation cooling type rotary machine in which a refrigerant is circulated to cool the inside of the rotary machine. It is characterized in that the conductive wire is covered with a material having heat resistance, water resistance and insulation.

The liquid circulation cooling type rotary machine according to the present invention for solving the above-mentioned problems is characterized in that the above-mentioned material is coated with the above-mentioned material having heat resistance, water resistance and insulation in vacuum. .

A liquid circulation cooling type rotary machine according to the present invention which solves the above-mentioned problems is characterized in that the material having heat resistance, water resistance and insulation is a fluorine resin.

The liquid circulation cooling type rotary machine according to the present invention for solving the above-mentioned problems is characterized in that the fluororesin is a tetrafluoroethylene-hexafluoropropylene copolymer.

The liquid circulation cooling type rotary machine according to the present invention for solving the above-mentioned problems is characterized in that the fluororesin is a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer.

The liquid circulation cooling type rotary machine according to the present invention which solves the above-mentioned problems is characterized in that the fluororesin is a chlorotrifluoroethylene-ethylene copolymer.

In the liquid circulation cooling type rotary machine according to the present invention for solving the above-mentioned problems, the above-mentioned heat-resistant, water-resistant and insulating material is modified by mixing polytetrafluoroethylene particles into a heat-resistant resin such as polyimide. It is characterized by using a fluorocarbon resin material.

The liquid circulation cooling type rotary machine according to the present invention for solving the above-mentioned problems is characterized in that the material having heat resistance, water resistance and insulation is polyetheretherketone.

A liquid circulation cooling type rotary machine according to the present invention which solves the above-mentioned problems is characterized in that the material having heat resistance, water resistance and insulation is polyether sulfone.

[0040]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, a liquid circulation cooling type rotating machine in which a refrigerant is flown into the rotating machine to directly cool the inside of the rotating machine is used. 1) Cooling method using low viscosity inert liquid,
(2) A cooling method using water was adopted. When a low-viscosity inert liquid is used as the refrigerant, it can be applied as is to the current coil insulation structure, and the loss of the external cooling auxiliary equipment can be maintained as it is, and the circulation speed of the refrigerant can be increased, and cooling can be performed. You can improve your ability.

However, when water is used as the refrigerant, the conventional coil insulation structure uses a resin (resin compound) such as polyimide and is not water resistant. Therefore, water resistance,
A coated electric wire using a fluorine-based resin having excellent heat resistance and electric insulation was used as a coil. With this configuration, water can be used as a refrigerant, and the cooling capacity can be improved. According to the present invention, a liquid circulation cooling type rotating machine can be made compact without causing thermal runaway.

(First Embodiment) As a first embodiment,
In a liquid circulation cooling type rotating machine, a low viscosity inert liquid is used as a refrigerant. The configuration of the rotary machine may be the same as that of the oil-cooled rotary machine shown in FIG. As the low-viscosity inert liquid, an organic heating medium oil, a fluorine-based inert liquid, a fluorine-based heating medium oil, or the like is used to cool the inside of the rotating machine. When the above-mentioned refrigerant is used, it is not necessary to subject the coil to a special treatment, and the conventional insulating structure can be used.

Example 1 As an example of the first embodiment
As a refrigerant, an organic heat carrier oil (kinematic viscosity: 15 × 10 ^-6m²
/ S or less) was used. Organic heat transfer oil is used in conventional hydraulic
Since the kinematic viscosity is lower than that of refrigerants such as hydraulic oil, existing cooling equipment
Improving cooling performance by increasing the flow rate just by applying
can do.

Example 2 As another example of the first embodiment, a fluorine-based inert liquid (kinematic viscosity: 12 × 1) was used as the refrigerant.
0 ^-6 m ² / s or less) was used. Fluorine-based inert liquid,
Since the kinematic viscosity is lower than that of conventional hydraulic fluids such as refrigerants, the flow rate can be increased and the cooling performance can be improved simply by applying it to the existing cooling device as it is. Furthermore, since it is an inert liquid, it has a flash point. There is no danger of fire.

Example 3 As another example of the first embodiment, a fluorine-based heat carrier oil (kinematic viscosity: 5 × 10 ⁻⁶⁾ was used as the refrigerant.
m ² / s or less) was used. Since fluorinated heat carrier oil also has a lower kinematic viscosity than refrigerants such as conventional hydraulic oil, the flow rate can be increased and the cooling performance can be improved by simply applying it to the existing cooling device. Being a liquid, it has no flash point and no fire hazard.

(Second Embodiment) As a second embodiment,
In a liquid circulation cooling type rotating machine, water resistance, heat resistance, and heat resistance due to heat-resistant, water-resistant and insulating materials such as fluororesin,
An insulated conductor wire (eg, copper wire) is used as a coil, and water is used as a coolant. The basic structure of the rotary machine is the same as that of the oil-cooled rotary machine shown in FIG. 4, but as described above, the coil is made of fluororesin, etc.
It is composed of insulated copper wire.

(Example 4) As an example of the second embodiment, a fluororesin, FEP (tetrafluoroethylene-), which has water resistance in the coil insulating material and is heat resistant at a continuous use temperature of 200 ° C. Hexafluoropropylene copolymer) was used. FEP has a breakdown voltage of 24 kV /
mm, which is 1.5 compared to 16 kV / mm of ETFE.
Has double the dielectric strength.

FIG. 1 is a sectional view of a heat-resistant / water-resistant / insulated electric wire showing an example of an embodiment according to the present invention. As shown in FIG. 1, the heat-resistant / water-resistant / insulated copper wire according to the present invention includes a copper wire 1 which is a conducting wire for passing an electric current, a nickel plating 2 coated around the copper wire 1, and a nickel plating 2 surrounding the copper wire 1. And FEP resin 3a having heat resistance, water resistance and insulation.

As the copper wire 1, a rectangular copper wire having an excellent space factor was used. The standard is CuSA and the size is 3.5 x 2.0 m.
m. When coating the flat copper wire with FEP, as shown in FIG. 1, as a countermeasure against copper damage, nickel plating was performed and then coating processing was performed. The material is particulate F
EP was used. The coating thickness is 170 μm.

Instead of using the particulate FEP, a liquid FE that can make the thickness of one coat thinner than the particles
P can also be used. Coating thickness is 100
μm.

The coil using the conventional fluororesin ETFE is intended for application to an underwater rotating machine, and is premised on continuous use at about 100 ° C. But,
In this embodiment, since FEP is used as the insulating material,
Since the coil temperature can be used up to a temperature range of 200 ° C., it can be applied to a rotating machine such as a generator as a C-type insulating material, and a high output can be achieved even with a small rotating machine. Also, compared with the conventional polyimide tape, the wear resistance and slipperiness of FEP are very excellent, which improves workability of inserting the coil into the slot of the stator and damages the insulating material during the insertion work. And the long-term reliability of coil insulation is improved. Since the coating thickness is 170 μm, it is twice as thick as when using a polyimide tape, but since the fluororesin has excellent wear resistance and slipperiness, the hole diameter of the slot is Does not require as much margin. Therefore, the FEP coated coil can be applied without changing the current slot diameter.

By using liquid FEP,
Furthermore, the FEP coating thickness can be reduced. Therefore, the slot diameter can be reduced and the cross-sectional shape of the rotating machine can be further reduced. Alternatively, it is possible to expect a further improvement in the exhaust heat capacity by passing the refrigerant through the gap in the slot without changing the slot diameter.

(Example 5) As another example of the second embodiment, a fluororesin or PFA having a coil insulating material having water resistance and having a continuous use temperature of 260 ° C and heat resistance.
(Tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer) was used. The breakdown voltage of PFA is equivalent to that of FEP. A particulate PFA is used as the material, and the coating thickness is 170 μm.

Instead of using the particulate PFA, a liquid PF that can make the thickness of one coat thinner than the particles.
It is also possible to use A. Coating thickness is 100
μm.

By using PFA as the insulating material of the coil, the heat resistance of the coil can be further improved.
Further, by using liquid PFA, the coating thickness of PFA can be reduced. Therefore, reduce the slot diameter,
The cross-sectional shape of the rotating machine can be made smaller. Alternatively, it is possible to expect a further improvement in the exhaust heat capacity by passing the refrigerant through the gap in the slot without changing the slot diameter.

(Example 6) As another example of the second embodiment, as in Example 5, the coil insulating material is water resistant, and the continuous use temperature is 260 ° C and the heat resistant PF.
A was used. Further, in the present embodiment, the PFA coating process is performed directly on the copper wire in a vacuum, so that the underlying treatment such as nickel plating as a countermeasure against copper damage is unnecessary. Liquid PFA is used as the material, and the coating thickness is 100 μm.

FIG. 2 is a sectional view of a heat-resistant / water-resistant / insulated electric wire showing another example of the embodiment according to the present invention. As shown in FIG. 2, the heat-resistant / water-resistant / insulated copper wire according to the present invention is covered with a copper wire 1 which is a conducting wire for passing an electric current and around the copper wire 1.
It has a PFA resin 3b having heat resistance, water resistance and insulation. A rectangular copper wire having an excellent space factor is used for the copper wire 1, the standard is CuSA, and the size is 3.5 × 2.0 mm.

In this embodiment, PFA is directly applied to a copper wire in vacuum.
Oxygen, which causes copper damage, can be removed from between the copper wire and PFA because the coating treatment of No. 1 is performed, and there is no need to perform nickel plating, which is a base treatment for copper damage prevention, and the plating step is omitted. Therefore, the coil can be manufactured in a shorter time and at low cost. The coating of the copper wire in vacuum as described above can be performed by using another coating material.

(Example 7) As another example of the second embodiment, ECTFE (chlorotrifluoroethylene-ethylene), which is a kind of fluororesin having water resistance and heat resistance in the insulating material of the coil, is used. Copolymer) resin was used. This is a material that enables coating based on ECTFE. Dielectric breakdown voltage is 31kV / mm,
The continuous use temperature is 180 ° C. Coating thickness is 3
It is 00 μm.

In ETFE, the adhesion strength before and after the steam test of 8 hours × 7 cycles decreased from 63 N to 6.9 N, but in ECTFE it did not change to 63 N at all.
From this, by using ECTFE as the insulating material,
As compared with ETFE, floating and peeling of the coating film can be significantly reduced. If floating or peeling occurs, stress may be applied to the insulating material due to interference with other parts, and cracks may occur, or the floating portion of the insulating material may impede the flow of the refrigerant and reduce the heat exhaust capacity. There is. For this reason,
By using ECTFE to reduce lift and delamination, long term reliability can be improved.

Example 8 As another example of the second embodiment, a modified fluororesin material obtained by mixing PTFE (polytetrafluoroethylene) particles with a heat resistant resin such as polyimide is used as the insulating material of the coil. It has water resistance, heat resistance and insulation. The modified fluororesin is a material in which the contradictory conditions such as excellent characteristics of PTFE and low cost are balanced in a high dimension. The continuous use temperature is 218 ° C. Since the form is liquid, thin coating can be performed. The coating thickness is 120 μm.

In this embodiment, by using the modified fluororesin as the insulating material of the coil, the heat resistance equivalent to that of FEP can be obtained.
It can be realized at a cost of 2/3.

(Example 9) As another example of the second embodiment, PEEK (polyether ether ketone) which is an engineering plastic excellent in heat resistance and water resistance was used as the insulating material of the coil. This is a material that enables coating based on PEEK. The dielectric breakdown voltage is 19 kV / mm, and the continuous use temperature is 260 ° C. Since PEEK is also coated at high temperature, nickel plating was applied as a countermeasure against copper damage. The coating thickness of PEEK is 300 μm.

In this embodiment, PEEK is used as the coil insulating material.
By using, the insulation characteristics equivalent to ETFE,
Higher heat resistance can be realized.

(Example 10) As another example of the second embodiment, PES (polyether sulfone) which is an engineering plastic excellent in heat resistance and water resistance was used as the insulating material of the coil. The material is a PES coating grade. Breakdown voltage is 31kV / m
m, continuous use temperature is 180 ° C. Since PES is also coated at high temperature, nickel plating was applied as a countermeasure against copper damage. The coating thickness is 300 μm.

In the present embodiment, since PES is used as the insulating material of the coil, it is possible to realize the insulation characteristic equal to or higher than ETFE and higher heat resistance.

FIG. 3 is a cooling performance test in which the operating time of the rotating machine and the temperature of the refrigerant in some of the examples described above are graphed. As conventional examples for comparison, one using hydraulic oil as the refrigerant and one using water as the refrigerant and fluororesin (ETFE) as the coating of the coil copper wire are also shown.

The example in which the cooling performance test was performed is the same as Example 1.
A rotary machine using an organic heat carrier oil as a refrigerant, a rotary machine using a fluorine-based inert liquid as a refrigerant in Example 2, a rotary machine using a fluorine heat carrier oil as a refrigerant in Example 3, and an example. Rotating machine using water as the refrigerant of 4 and using the electric wire coated with fluororesin (PFA) for the coil, rotation using water as the refrigerant of Example 5 and using electric wire coated with the fluororesin (FEP) for the coil There are five or more machines.

As shown in the graph of FIG.
Since Nos. 2 and 3 have lower kinematic viscosities than hydraulic fluids that are conventional refrigerants, the flow rate is increased by simply applying them to existing cooling devices, so that the cooling performance can be improved.
Further, in Examples 4 and 5, water is used as the refrigerant, and the kinematic viscosity is low and the heat capacity is large as compared with the hydraulic fluid. Cooling performance could be improved by using a coated copper wire made of fluorine-based resin PFA or FEP having excellent water resistance, heat resistance, and electrical insulation for the coil insulation structure.

In the graph of FIG. 3, it is understood that the relationship between the rotary machine operating time and the refrigerant temperature does not mean that the lower the viscosity of the refrigerant is, the better the cooling capacity is. This is because the heat capacity and heat conduction of the refrigerant also affect.

[0071]

According to the first aspect of the present invention, in a liquid circulation cooling type rotary machine that circulates a cooling medium for cooling, the cooling medium is a low viscosity inert liquid. The cooling performance can be improved by increasing the flow rate of the refrigerant without changing the configuration of the rotating machine, and the rotating machine can be downsized.

According to the inventions of claims 2 to 3, since the low-viscosity inert liquid is a fluorine-based heat carrier oil or a fluorine-based inert liquid, the cooling performance of the rotating machine is improved. Therefore, the rotating machine can be downsized, and the refrigerant has no flash point, eliminating the risk of fire.

According to the invention of claim 4, in a liquid circulation cooling type rotary machine for cooling by circulating a refrigerant inside,
Since the refrigerant is water and the conductors forming the coils inside the rotating machine are covered with a material having heat resistance, water resistance and insulation, cooling performance using water with excellent heat discharge capacity as a refrigerant Can be improved, and the size of the rotating machine can be reduced.

According to the invention of claim 5, since the conductive wire is covered with the heat-resistant, water-resistant and insulating material in a vacuum, no countermeasure against copper damage is required, and the coil can be more effectively removed. It can be manufactured in a short time and at low cost.

According to the invention of claim 6, since the heat-resistant, water-resistant and insulating material is made of a fluororesin, it is possible to use water as a refrigerant, and the rotary machine The cooling performance can be improved and the rotating machine can be downsized. In addition, since the fluororesin is excellent in slipperiness, it is easy to insert the coil into the stator, the workability is improved, and the wear resistance is also excellent.
Damage to the fluorine resin coating can be suppressed, and long-term reliability of coil insulation can be improved.

According to the invention of claim 7, since the fluororesin is a tetrafluoroethylene-hexafluoropropylene copolymer, the rotating machine can be used at high temperatures, and the rotating machine can be made compact. And higher output are possible.

According to the invention of claim 8, since the fluororesin is a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, the rotating machine can be used at a higher temperature, and the rotating machine can be further rotated. It is possible to downsize the machine and increase the output.

According to the invention of claim 9, since the fluororesin is a chlorotrifluoroethylene-ethylene copolymer, the rotating machine can be used up to a high temperature, and the rotating machine can be miniaturized. Also, higher output is possible.
Further, since the adhesion strength does not change with time, peeling of the coating can be significantly suppressed and the long-term reliability of coil insulation can be improved.

According to the tenth aspect of the invention, the heat resistant, water resistant and insulating material is a modified fluororesin material obtained by mixing polytetrafluoroethylene particles in a heat resistant resin such as polyimide. Therefore, heat resistance, water resistance and insulation of the coil can be realized at low cost.

According to the eleventh to twelfth aspects of the present invention, since the material having heat resistance, water resistance and insulation is polyether ether ketone or polyether sulfone, the conventional coil Higher heat resistance and higher insulation can be achieved compared to insulating materials.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a heat-resistant / water-resistant / insulated electric wire showing an example of an embodiment according to the present invention.

FIG. 2 is a heat resistance diagram showing another example of the embodiment according to the present invention.
It is sectional drawing of a water resistant / insulated electric wire.

FIG. 3 is a graph of the temperatures of the refrigerants of Examples and Comparative Examples according to the present invention with respect to the operating time of the rotating machine.

FIG. 4 is a schematic view of a structure of a conventional oil-cooled rotary machine.

FIG. 5 is a schematic view of a structure of a conventional water-cooled rotary machine.

FIG. 6 is a sectional view of a conventional waterproof copper wire.

[Explanation of symbols]

1 copper wire 2 Nickel plating 3a FEP resin 3b PFA resin

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 5H603 AA13 AA17 BB01 CA01 CB01                       CB22 CE13 FA05 FA16 FB07                 5H604 AA02 BB01 BB14 CC01 CC11                       DA14 PA07 PB01 PE01                 5H609 BB01 PP02 PP06 PP07 QQ01                       QQ04 QQ10 QQ13 RR01 RR46

Claims (12)

[Claims] 1. A liquid circulation cooling type rotary machine for cooling by circulating a refrigerant inside, wherein the refrigerant is a low viscosity inert liquid. 2. The liquid circulation cooling rotary machine according to claim 1, wherein the low-viscosity inert liquid is a fluorine-based heat transfer medium oil. 3. The liquid circulation cooling rotary machine according to claim 1, wherein the low viscosity inert liquid is a fluorine-based inert liquid. 4. A liquid circulation cooling type rotary machine which circulates a cooling medium for cooling, wherein the cooling medium is water, and a wire forming a coil inside the rotating machine has heat resistance, water resistance and insulation. A liquid circulation cooling type rotary machine characterized by being coated with. 5. The liquid circulation cooling rotary machine according to claim 4, wherein the material having heat resistance, water resistance and insulation is coated on the conductor in vacuum. Cooling type rotating machine. 6. The liquid circulation cooling type rotary machine according to claim 4 or 5, wherein the material having heat resistance, water resistance and insulation is a fluorine resin. Machine. 7. The liquid circulation cooling type rotating machine according to claim 6, wherein the fluororesin is tetrafluoroethylene-
A liquid circulation cooling type rotary machine characterized by being a hexafluoropropylene copolymer. 8. The liquid circulation cooling type rotating machine according to claim 6, wherein the fluororesin is tetrafluoroethylene-
A liquid circulation cooling type rotary machine characterized by being a perfluoroalkyl vinyl ether copolymer. 9. The liquid circulation cooling type rotary machine according to claim 6, wherein the fluororesin is a chlorotrifluoroethylene-ethylene copolymer. 10. The liquid circulation cooling type rotary machine according to claim 4, wherein the heat resistant, water resistant and insulating material is a modified fluorine obtained by mixing a polytetrafluoroethylene particle with a heat resistant resin such as polyimide. Liquid circulation cooling type rotary machine characterized by using a resin material. 11. The liquid circulation cooling type rotary machine according to claim 4, wherein the material having heat resistance, water resistance and insulation is polyetheretherketone. 12. The liquid circulation cooling type rotary machine according to claim 4, wherein the material having heat resistance, water resistance and insulation is polyether sulfone.