JP5444134B2 - Stator heating method and apparatus using induction heating - Google Patents

Description

  The present invention relates to an electric wire coil wound around a stator of an electric motor (motor), an electric generator (generator), or an electric machine having both functions (hereinafter referred to as “electric machine” including claims). Further, the present invention relates to a technical field relating to preheating for removing moisture from the stator core and annealing treatment, and heating for curing the varnish after application of the varnish (hereinafter referred to as “main heating”).

  As already known from the following Patent Documents 1 to 3, a motor, a generator, and the like, that is, an electric machine is conventionally used as a method for heating an electric wire coil or a stator wound around a stator, during preliminary heating. In order to perform the main heating, a method of heating the stator in a drying furnace is performed. As a heat source for the drying furnace, an electric heater or a method of exchanging heat of steam has been used relatively often. In the case of this method, it is necessary to previously heat the atmosphere of the entire drying furnace to a temperature necessary for heating the stator, and the energy efficiency is low because the necessary temperature is maintained for a necessary time.

  As another method, a method of heating by using self-heating of the wire coil itself by flowing a large electric power directly to the wire coil wound around the stator has been performed. This is hereinafter referred to as an electric heating method. In the case of this energization heating method, it is possible to damage the electric wire coil itself by flowing a large electric power through the electric wire coil that is a product, and in recent years to reduce the resistance of the electric wire coil as much as possible in order to improve the efficiency of motors and the like In this method, there is a problem that the power to be passed through the wire coil must be further increased.

  Both are bottleneck items from the viewpoint of energy saving when viewed from the energy required for heating.

  Further, in the case of this energization heating method, an electric spark is generated from a flawed portion such as a minute pinhole or winding in the electric wire coil, and there is a risk of occurrence of the worst fire. This risk is particularly high in the case of materials such as varnishes that contain many solvents with low flash points.

  In addition, there is a method of induction heating of a stator as a heating method of an electric machine such as a motor or a generator. This method has been widely used for preheating conventionally, but has not been applied to the main heating. In the preheating, as described in the previous section, since heating for a short time at a temperature slightly above 100 ° C. that can remove moisture was sufficient, it was possible to carry out with relatively no problem. However, this heating is a so-called indirect heating method that conducts heat generated when the stator is induction-heated to the wire coil, so the stator surface is first heated to a high temperature and the heat is protected outside the wire coil. It is necessary to transfer heat to the electric wire coil through the insulating material, and to maintain this for a relatively long time until the varnish curing reaction is completed. In addition, the temperature at which the varnish is cured is generally higher than the temperature at which moisture can be removed. Therefore, in order to heat the varnish to a temperature suitable for the curing temperature of the varnish applied to the electric wire coil, indirect heating results. The heating level during induction heating of the stator, which is a part, must be strengthened. For this reason, the volatile matter of the varnish foams due to concerns about the thermal deterioration of the stator and rapid heating due to induction heating. Practical for reasons such as there is a concern that curing will be completed without being pulled out, and as a result, there is a concern that it will cure in the form of bubbles, and there is a problem of deterioration of heat influence on the insulation covering the outside of the wire coil It was not converted.

  Also, as a recent issue, varnish VOC regulations (suppression of release of varnish volatile components into the atmosphere), the solvent component contained in the varnish must be suppressed. In this case, the viscosity of the varnish is increased and fixed. There is a problem that it becomes difficult for the varnish to penetrate into the slot portion in which the wire coil inside the child is inserted.

JP 2005-86954 A JP 2008-193875 A JP 2009-283439 A

  The present invention relates to a method for induction heating the surface of a stator, and the stator surface temperature is higher than that of an electric wire coil. The concern is that the stator is thermally deteriorated at a high temperature, and the volatile matter of the varnish is foamed due to rapid heating. This solves the problem that air bubbles are hardened and bubbles are generated inside, and further, the problem that the insulating material covering the outside of the wire coil deteriorates due to the heat effect is solved.

  That is, the object of the present invention is to sufficiently introduce the varnish into the stator slot even in the case of a varnish having a high viscosity in compliance with the VOC regulations, and to improve the energy efficiency as compared with the conventional method. A heating method and a heating apparatus are provided.

  The present invention solves the above-mentioned problems by optimizing the combination of conditions such as induction heating conditions and varnish application conditions when induction heating of the stator, and also by optimizing the heating temperature profile. It is a feature. More specifically, the method and apparatus for heating a stator by induction heating according to the present invention provides the heating temperature during induction heating to the stator surface, the temperature of the coil end portion and the stator surface, and the center inside the slot. While keeping the temperature difference between the portions as small as possible, the central portion inside the slot is heated to the upper limit temperature of the insulating material, and the coil end portion is heated to a temperature suitable for the curing temperature of the varnish used.

  At this time, the temperature difference is set so that the central portion inside the slot is slightly higher than the coil end portion.

  More specifically, according to the present invention, in order to achieve the above-described object, first, a stator for induction heating a stator of an electric machine to cure a varnish applied in the vicinity of a coil wound around the stator. Inductor heating method, wherein the induction heating part covers at least half of the outer part of the stator close to each other, and the induction heating current flowing through the coil in the induction heating part is in one direction. There is provided a method for heating a stator by induction heating in which a heating coil is arranged, an induction heating current is supplied to the induction heating coil, and the stator is heated while rotating.

  Further, according to the present invention, in order to achieve the above-described object, the varnish applied in the vicinity of the coil wound around the stator of the electric machine is preheated, cooled, varnished, heated, A stator heating method in which a stator is heated to be cured by a temperature profile consisting of temperature holding, wherein the induction heating portion covers at least half or more of the outer portion of the stator in close proximity, and the induction heating is performed. The induction heating coil is arranged so that the induction heating current flowing in the coil in one part is in one direction, and the induction heating coil is supplied to the induction heating coil in the preheating, temperature rising and temperature holding of the temperature profile, and A method of heating a stator by induction heating in which the stator is heated while rotating is provided.

In the present invention, in the method for heating a stator by induction heating described above, in maintaining the temperature profile, the center surface temperature of the stator and the temperature in the central portion of the slot are substantially set to the heat resistance temperature of the insulating material. In addition, it is preferable that the temperature of the coil end of the stator is a varnish curing temperature lower than the heat resistance temperature of the insulating material, or the application of the varnish from the gradient of the temperature rise of the stator in the preheating of the temperature profile. It is preferable to lower the slope of the temperature rise in the subsequent temperature increase.

  In addition, according to the present invention, in order to achieve the above-described object, a stator heating device for inductively heating the stator of the electric machine to cure the varnish adhering to the vicinity of the coil wound around the stator. A stator chuck jig for holding the stator while rotating, a pair of coil end atmosphere heat retaining covers disposed at both ends of the stator held by the stator chuck jig, and the stator chuck jig Induction heating part that can cover at least half or more of the outer surface of the stator held by the coil close to each other, and the induction heating current flowing in the coil in the induction heating part is in one direction. And a stator heating device by induction heating that heats the stator by supplying an induction heating current to the induction heating coil.

  According to the present invention, in the stator heating device described above, it is preferable to further provide a wanister drop receiving portion below the stator held by the stator chuck jig, or the induction heating coil. It is preferable to make the coil winding dose at the central part of the induction heating coil circuit constituting the coil larger than the coil winding dose at both sides of the induction heating coil circuit. Further, in the stator heating device described above, the return circuit portion of the induction heating coil is disposed below the stator and away from the stator, or the coil end atmosphere heat insulation cover is induced. The stator in which the return circuit portion of the induction heating coil is applied to the coil end atmosphere heat insulation cover, or at least one of the coil end atmosphere heat insulation cover is held by the stator chuck jig while being formed of a heating material. It is preferable that it can move with respect to.

  According to the above-described method of heating a stator by induction heating and a heating apparatus according to the present invention, since it is possible to control to input energy only when necessary, the conventional drying furnace system always operates even when empty such as waiting for work. Compared to the situation where energy must be input, a significant reduction in energy becomes possible. At this time, the temperature difference is set so that the central portion inside the slot is slightly higher than the coil end portion. As a result, the viscosity of the varnish in the central portion inside the slot can be lowered from the coil end portion. For this reason, there is an advantage that the varnish can sufficiently penetrate into the slot by capillary action. As a result, there is an advantage that the varnish can be filled in the slot more sufficiently than the conventional varnish even when the varnish has high viscosity according to VOC regulations.

It is a figure which shows the structure of the heating apparatus of the stator by the induction heating which becomes Example 1 of this invention. It is a figure which shows the structure of the heating apparatus of the stator by the induction heating which becomes Example 2 of this invention. It is a figure which shows the structure of the heating apparatus of the stator by the induction heating which becomes Example 3 of this invention. It is a figure which shows the structure of the heating apparatus of the stator by the induction heating which becomes Example 4 of this invention. It is a figure which shows the structure of the heating apparatus of the stator by induction heating which becomes Example 5 of this invention. It is a figure which shows the temperature profile at the time of induction heating of the stator by said Example. It is a figure which shows the varnish filling state in the slot part of the stator obtained by said Example.

  FIG. 1 shows a configuration of a stator heating device by induction heating according to Embodiment 1 of the present invention.

  In FIG. 1A, reference numeral 7 denotes a coil end atmosphere heat insulation cover provided at both ends of the stator attached to the vicinity of the coil around which the varnish is wound around the stator, and reference numeral 6 denotes an induction heating coil. Is shown. Further, below the coil end atmosphere heat retaining cover 7, a wanister tray drop receiver 9 is provided. FIG. 1 (B) shows the AA ′ cross section in FIG. 1 (A). The outer shape of the stator 1 having a substantially cylindrical shape is formed with a plurality of slot portions 2 on its inner peripheral surface side, The electric wire coil 3 is wound around the inside and further across both ends (coil end portion 5) of the stator. In addition, a stator chuck jig 8 is inserted into the stator 1 through one coil end atmosphere heat insulating cover 7 to fix the stator. Further, in the figure, reference numeral T16 indicates the temperature of the stator center surface, T17 indicates the temperature of the central portion inside the slot, and T18 indicates the temperature of the coil end portion. In FIG. 1C, the stator 1 is indicated by a broken line, and in particular, the circuit of the induction heating coil 6 (winding (wiring) state of the induction heating coil) is shown, which is also apparent from this figure. As described above, the induction heating coil 6 is configured by winding the coil a plurality of times, and a part (induction heating portion) thereof is attached so as to cover the outer periphery of the stator 1. When the varnish is cured, although not shown here, the stator 1 is rotated by rotating the stator chuck jig 8 with a motor or the like, for example.

  Further, as is apparent from the above figure, when the varnish applied (dropped) in the vicinity of the coil end portion 5 is infiltrated and cured, the induction heating coil 6 disposed close to the outside of the stator 1, particularly In the induction heating portion of the induction heating coil 6, in order to allow a current to flow in one direction in the coil wound a plurality of times (see the arrow in FIG. 1C), these coils are used for the stator 1. It arrange | positions along an outer peripheral surface. More specifically, here, as an example, the current flowing through the induction heating coil 6 is set to flow only in a direction perpendicular to the rotation axis direction of the substantially cylindrical stator 1. However, the flow of the induction heating current may be in one direction, and the direction is not defined. The portions other than the induction heating portion of the induction heating coil 6 are hereinafter also referred to as “induction heating current return” or “U-turn portion”.

  At the same time, the induction heating coil 6 does not cover the entire circumference of the stator 1, that is, the induction heating part of the induction heating coil 6 is the induction heating part of the stator 1 to which the induction heating part is induction-heated. In other words, it is set so as to cover only about two-thirds to half of the outer portion (that is, the heated region) to be suppressed from about two-thirds to about half. The other part of the induction heating coil 6 and the part other than the induction heating part, that is, the return circuit part are arranged so as to be separated from the stator 1.

  According to the configuration of the heating device described above, the stator 1 can be heated relatively uniformly. In addition, in the mixed part where the circuit of the induction heating coil 6 interferes with the stator 1 in both directions (the circuit of going and returning), the energy of induction heating becomes unstable. As described above, the return circuit portion is disposed away from the stator 1 to eliminate the problem. In particular, in the case of the stator 1 or the like in which the surface of the stator 1 is integrally fixed by welding or the like after the steel plates are laminated to form a stator shape, the stator 1 is welded to the stator 1. A lot of induction heating is generated, and the surface of the stator 1 is rapidly heated, and as a result, a temperature difference from the coil end portion 5 is increased. Therefore, as described above, it is important to make the current flow in one direction.

  Moreover, since the electric wire coil 3 of the coil end part 5 is scattered or swells before the varnish is hardened, it is fixed in advance by being tied with a string 10 or the like, or the coil end part 5 which is an electrical entrance / exit of the electric machine. The lead wire 4 is fixed by a lead tube protective tube, but these are not metals, so their thermal conductivity is poor, and heat is not sufficiently transferred by only the heat conduction of the induction heating coil 6. Therefore, the varnish adhering to this part is hard to harden. In particular, when the outside air temperature is low, heat radiation from the coil end portion 5 is intense, and it becomes more difficult to cure the string 10 in this portion. As a countermeasure against this, the ambient temperature cover 7 for covering the coil end portion 5 stabilizes the ambient temperature around the coil end. This makes it possible to completely cure the string 10 and the varnish of the lead protection tube at the base of the lead side 4, and this is also a great feature.

  As described above, the varnish application method is a method in which the varnish is dropped onto the coil end portions 5 on both sides while rotating the stator 1 in the circumferential direction and in one direction while holding the stator 1 almost horizontally. The methods relating to rotation, the dropping nozzle and the dropping position are omitted because they are already known cases.

  FIG. 2 shows the configuration of the heating apparatus according to the second embodiment of the present invention. Also in this embodiment, the same constituent elements as those in the above embodiment are indicated by the same reference numerals as above.

  The second embodiment is substantially the same as the first embodiment, but the difference is related to the circuit of the heating induction coil 6, and the winding dose (number of coils) of the induction heating coil 6 in the central portion of the stator 1 is increased. Specifically, in this example, the number of coils at the center is three, and the number of coils on both sides is two. As a result, the vicinity of the center of the stator 1 is strongly induction-heated, and the temperature of the central portion of the stator 1 can be slightly higher than that of the coil end 5, so that the varnish is sucked into the slot portion 2 from the coil end portion 5. It is a device devised to be This embodiment is effective when the heat-resistant upper limit temperature of the insulating material is relatively high.

  FIG. 3 shows a configuration of a heating apparatus according to Embodiment 3 of the present invention. Also in this embodiment, the same constituent elements as those in the above embodiment are indicated by the same reference numerals as above.

  In the third embodiment, the current flow of the induction heating coil 6 is unidirectional, and the lower induction heating coil 6 is also wound around the stator 1 below, but below the varnish dripping tray 9. On the side, the dripping varnish is prevented from adhering to the induction heating coil 6. Then, the varnish drip receptacle 9 is received while the varnish drip receptacle 9 is wound together (for example, a belt-shaped member is wound around a pair of rollers). According to this, it is possible to automatically collect the sagging drop varnish, for example, by winding up the varnish drip tray. This is an effective method for rationalizing the cleaning work of the sagging varnish.

  It should be noted that the material for the alligator drop receptacle 9 is preferably a non-inductive heating material such as paper or plastic that has high permeability.

  As a result, the heating level of the induction heating energy to the stator 1 of the lower induction coil 6 is also lowered, however, it is possible to use the energy more effectively than in the prior art. It should be noted that it is desirable not to lower the lower part as much as possible while considering the workability of the cleaning work.

  FIG. 4 shows the configuration of a heating apparatus according to Embodiment 4 of the present invention. Also in this embodiment, the same constituent elements as those in the above embodiment are indicated by the same reference numerals as above.

  The fourth embodiment is a system that effectively uses the current flow (return circuit portion) on the opposite side of the stator 1 while making the current flow of the induction heating coil 6 unidirectional with respect to the stator 1. . More specifically, the coil end atmosphere heat insulating cover 7 is formed of an induction heating material such as metal or ceramic mixed with metal (hereinafter referred to as “coil end atmosphere heating material”), and the opposite side is also provided. An electric current is applied to the coil end atmosphere heating material 7 and the coil end atmosphere heating material 7 is induction-heated, so that the wire 10 in the coil end portion 5 has a string 10 or an electric doorway of the electric machine. A varnish adhering to the root of a lead wire protection tube or the like on the lead side 4 of a certain coil end portion 5 can be indirectly heated. That is, in addition to the above, this embodiment also has the function of stabilizing the ambient temperature of the coil end portion 5 and completely curing the varnish of the string 10 and the lead protection tube at the base of the lead side 4. Yes.

  In addition, the coil end atmosphere heating material 7 of this embodiment has a mechanism that can slide in the lateral direction on both sides, and it is assumed that the varnish has sufficiently penetrated into the slot 2 and is slid laterally. The tube on the lead side 4 can be heated.

  Further, the system of this embodiment has an advantage that the power can be used more effectively than the other embodiments described above because the return circuit is effectively used for heating the coil end atmosphere heating material 7.

  FIG. 5 shows the configuration of a heating apparatus according to Embodiment 5 of the present invention. Also in this embodiment, the same constituent elements as those in the above embodiment are indicated by the same reference numerals as above.

  The fifth embodiment is basically the same as the fourth embodiment, except that the U-turn portion (return circuit portion) of the induction heating coil 6 is not bent, and the lower portion outside the arc of the induction heating coil 6 is lowered directly below. This is an example of making a U-turn in a standing state. In Example 5, both of the above Example 4 and the stator 1, the return induction heating coil 6 has a transverse induction coil for indirect heating of the coil end atmosphere heating material 7. It is characterized by being separated so as not to adversely affect the heating.

  Next, FIG. 6 shows the details of the heating method of the stator according to the first to fifth embodiments, particularly the temperature profile thereof.

  This FIG. 6 shows a series of temperature profiles starting from preheating (preheating) S1 to the stator 1, passing through cooling S2, varnish application S3, temperature rising S4 and reaching temperature holding S5. The axis represents time, and the vertical axis represents temperature. That is, it is a temperature profile model including preheating S1, cooling S2, varnish application S3, temperature rise S4, temperature holding S5.

  The characteristics of this temperature profile are shown below. First, after preheating (preheating) S1 for moisture removal and annealing, varnish application S3 is started in the middle of cooling S2 of the stator 1. After this varnish application S3 is completed, a temperature increase S4 is started in order to cure the applied varnish. In order to prevent rapid heating, the temperature rise S4 is such that the foaming phenomenon of the volatile solvent contained in the varnish does not occur by using the induction heating coil 6 as shown in any of the first to fifth embodiments. A gentle curve is necessary. That is, the slope of the temperature rise at the temperature rise S4 is made smaller than the slope of the temperature rise at the preheating (preheating) S1. Further, when the temperature increase S4 reaches a temperature suitable for varnish curing determined for the varnish, the temperature and time are maintained under the conditions determined for the varnish in the temperature retention S5 in order to maintain this temperature.

  In addition, for example, at the timing of this temperature holding S5, the coil end atmosphere heat insulating cover 7 and the coil end atmosphere heating material 7 are slid (moved) sideways (see the white arrows in FIGS. 1 to 5), By maintaining the temperature around the coil end portion 5 at a temperature suitable for varnish curing, the varnish attached to the string 10 of the wire coil 3, the protective tube on the lead side 4, or the like can also be cured.

  Further, in this temperature profile model, when the surface of the stator 1 is induction-heated, a temperature difference ΔT is generated between the temperature T17 at the center portion inside the slot and the temperature T18 at the coil end portion 5 according to the order of heat transfer by indirect heating. Although generated, it is desirable that the temperature difference ΔT is slightly lower than the insulating material heat-resistant temperature Ti. This prevents deterioration of the insulating material and allows the varnish to sufficiently penetrate into the slot by capillary action. Thereby, high-density filling of the varnish into the inside of the slot part 2 is attained. The insulation heat resistance temperature Ti is a temperature determined from the guaranteed operating time of the product set for the product (for example, the motor) and the temperature rise condition of the motor determined from the guaranteed load condition, and is determined from the comprehensive conditions of these product specifications. It is common to select an insulating material that can withstand the worst conditions.

  It should be noted that the timing at which the coil end atmosphere heat retaining cover 7 is slid laterally and the coil end portion 5 is sealed is preferably after the volatile component of the varnish has completely evaporated. However, in the case of a large stator 1 or the like, the volatile matter may not be completely removed depending on the amount of varnish applied, so as shown in FIG. 4 and FIG. A method in which the material 7 is moved to the stator 1 side at the temperature holding 16 timing, and at this time, the string 10 and the protective tube of the coil end portion 5 are heated and cured while heating the coil end atmosphere heating material 7 by induction heating. It is also possible to perform.

  Further, FIG. 7 illustrates a stator manufactured by the above-described stator heating apparatus and method therefor.

  FIG. 7 (A) is an enlarged view of a part of the steel plate of the stator 1, and FIG. 7 (B) is an enlarged view of the slot portion 2. As shown in these drawings, Inside the slot portion 2, there are provided a plurality of electric wire coils 3 housed in an insulating material 23 and an insulating material 24 provided therein and having a circular cross section. Originally, the portion to be filled with the varnish is indicated by the varnish 25, that is, the space other than the electric wire coil 3 surrounded by the insulating material 22 and the insulating material 23, and the slot portion of a part (iron plate) 26 of the stator 1 2, the gap between the insulating material 23 and the insulating material 24, and the slot portion 2, and it is most ideal that these openings can be completely filled with varnish. This is because, if all of these can be filled in close contact with the varnish 25 without generating air bubbles, the generated heat generated when the electric power for operating the electric machine is energized to the electric wire coil is generated. Can efficiently dissipate heat to the stator 1 side, and the electric coil 3 vibrates due to minute electromagnetic induction when the electric machine is repeatedly operated and stopped, and the electric wire coil 3 rubs and wears, resulting in poor insulation. This is because it can also be prevented.

  FIG. 7C is a state diagram when, for example, the size of the circular shape of the cross section of the electric wire coil 3 is reduced (that is, the wire diameter is reduced) and wound with an extra fine wire. However, as the filling degree of the electric wire coil 3 increases (the improvement in the electric wire coil filling rate), the gap between the varnishes 25 to be filled decreases. Even in this case, according to the method of heating the stator by induction heating and the heating device of the present invention, the varnish 25 is caused by the temperature difference between the temperature 19 of the coil end portion and the temperature 18 of the central portion inside the slot. However, the feature (effect) of being easily penetrated into the slot portion 2 by the capillary phenomenon is achieved.

  As described in detail above, the present invention provides the following.

  That is, first, (1) an induction heating system having an induction heating coil and a coil core that supports the induction heating coil, the coil core is cylindrical or polygonal in cross section with a gap at the bottom. The induction heating coil is an induction heating system that forms a one-way circuit on the coil core except for a portion corresponding to the gap.

  Next, as (2), in the above (1), the winding dose (density) of the induction heating coil formed on the coil core is larger at the center than at both ends in the length direction of the coil core. Induction heating system to be formed.

  Further, as (3), in the above (1) or (2), a varnish drooping receiver is provided below the gap of the coil core, and the winding of the induction heating coil in a portion corresponding to the gap is It is an induction heating system arranged under the cradle.

  In addition, as (4), in the induction heating system in which the object to be heated having the stator, the slot portion, the electric wire coil, and the coil end portion is induction heated by the induction heating member of (1) to (3) above, induction heating is performed. In the induction heating system, the coil winding is formed in a reverse direction at a portion corresponding to the stator of the object to be heated and a portion corresponding to the coil end portion.

  Moreover, (5) is the induction heating system formed so that the induction heating coil in the above (4) is U-turned in a state in which the lower part removed from the coil core is lowered directly below.

  Moreover, as (6), the impregnation part which impregnates a to-be-heated material with a varnish, the preheating part which preheats a to-be-heated material before impregnation, or the hardening part which heat-hardens the varnish which impregnated the to-be-heated material after impregnation An electrical insulation processing apparatus having at least one of the induction heating apparatuses (1) to (5) as a heating means for an object to be heated in at least the preliminary heating section or the curing section. Processing system.

  Further, as (7), in (6) above, moisture is removed while raising the temperature in the preheating portion, varnish is impregnated while cooling in the impregnation portion, and the temperature is raised to a predetermined temperature and held in the curing portion. An electrical insulation system for curing a varnish.

  Further, (8) is an apparatus having an induction heating method and a hot air heating method in a heating device for curing a varnish applied or impregnated in a coil in a manufacturing process of an electric machine.

  Further, (9) is a heating apparatus having an exhaust system surrounding the electric machine for the purpose of exhausting volatile components from the varnish in the heating apparatuses (1) to (8).

  DESCRIPTION OF SYMBOLS 1 ... Stator, 2 ... Slot part, 3 ... Electric wire coil, 4 ... Lead side, 5 ... Coil end part, 6 ... Induction heating coil, 7 ... Coil end atmosphere heat insulation cover or coil end atmosphere heating material, 8 ... Stator chuck jig, 9... Wanistar drop receptacle, 10... String, 23 .. Insulating material, 24 .. Insulating material, 25 .. Varnish, 26.

Claims (8)

The stator is heated in order to cure the varnish applied in the vicinity of the coil wound around the stator of the electric rotating device according to a temperature profile including preheating, cooling, varnish application, temperature increase, and temperature holding. A method of heating the stator,
An induction heating coil is disposed so that the induction heating portion covers at least half or more of the outer portion of the stator in close proximity, and the induction heating current flowing through the coil in the induction heating portion is in one direction,
In the preheating, temperature rising, and temperature holding of the temperature profile, while supplying an induction heating current to the induction heating coil and heating the stator while rotating,
In the temperature maintenance of the temperature profile, the center surface temperature of the stator and the temperature in the central portion of the slot are substantially the insulating material heat resistant temperature, and the temperature of the stator coil end is lower than the heat insulating material heat resistant temperature A method of heating a stator by induction heating, characterized in that the varnish curing temperature is set . The method of heating a stator by induction heating according to claim 1 , wherein a slope of temperature rise of the stator in preheating of the temperature profile is made larger than a slope of temperature rise in temperature rise after application of the varnish. Stator heating method by induction heating characterized by A stator heating device that cures the varnish adhering to the vicinity of the coil wound around the stator by induction heating the stator of the electric rotating device,
A stator chuck jig for holding the stator while rotating;
A pair of coil end atmosphere heat insulation covers disposed at both ends of the stator held by the stator chuck jig;
An induction heating portion capable of closely covering at least half of the outer surface of the stator held by the stator chuck jig, and the induction heating current flowing through the coil in the induction heating portion is the same. An induction heating coil comprising: an induction heating coil, wherein the stator is heated by supplying an induction heating current to the induction heating coil. The stator heating device according to claim 3 , further comprising:
An apparatus for heating a stator by induction heating, wherein a wanister drop receiving portion is provided below the stator held by the stator chuck jig. 4. The stator heating device according to claim 3 , wherein the coil winding dose at the central portion of the induction heating coil circuit constituting the induction heating coil is set to be greater than the coil winding dose at both sides of the induction heating coil circuit. A stator heating device by induction heating, characterized by being enlarged. The stator heating device according to claim 3 , wherein the return circuit portion of the induction heating coil is disposed below the stator and away from the stator. Heating device. The stator heating device according to claim 3 , wherein the coil end atmosphere heat insulation cover is formed of metal, and a return circuit portion of the induction heating coil is applied to the metal coil end atmosphere heat insulation cover. Stator heating device by induction heating. 4. The stator heating apparatus according to claim 3 , wherein at least one of the coil end atmosphere heat insulating covers is movable with respect to the stator held by the stator chuck jig. Stator heating device by induction heating.

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