JP2010178554A - Method of impregnating stator core with varnish - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of impregnating a stator core with varnish capable of improving the efficiency of a varnish impregnating work through the suppression of the sag of varnish. <P>SOLUTION: The method of impregnating the stator core 10 with varnish includes: a dropping step; and a diffusion step. In the method, a winding 12 for the stator core is impregnated with varnish 40 by repeatedly carrying out a plurality of the combinations of the dropping steps and the diffusion steps. In the dropping step, varnish is dropped on the inclined upper 12a side in the winding while the stator core including the winding a stator winding is rotated around the central axis 0 of the stator core in a posture inclining the central axis 0 in the horizontal direction. In the diffusion step, the dropping of varnish is stopped, and dropped varnish is diffused into the winding while the stator core is rotated around the central axis in the posture horizontally returning the central axis. The rotational speed VR2 of the stator core in the diffusion step is faster than that VR1 in the dropping step. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a method for impregnating a stator core with a varnish.

  A stator core of an electric device includes a winding portion around which a stator winding is wound. As a technique for impregnating the winding portion with a varnish for insulation treatment, there is a dripping impregnation method (see Patent Document 1). Patent Document 1 discloses that the varnish is dropped on the inclined upper side of the winding portion while rotating the stator core around the central axis in a posture in which the central axis is inclined with respect to the horizontal. The varnish is dripped until the varnish flows out from the inclined lower side of the winding part.

Japanese Patent Laid-Open No. 7-67301

  However, since the varnish is caused to flow out from the inclined lower side of the winding part, the work for removing the varnish adhering to the stator core after the varnish is hardened increases. For this reason, a series of operations for impregnating the varnish becomes complicated, and it may be difficult to improve the efficiency of the varnish impregnation operation.

  The objective of this invention is providing the varnish impregnation method of a stator core which can aim at the efficiency improvement of a varnish impregnation operation | work through suppressing the dripping of a varnish.

  The stator core varnish impregnation method includes a dropping step and a diffusion step, and the winding portion of the stator core is impregnated with the varnish by repeatedly performing a combination of the dropping step and the diffusion step a plurality of times. In the dropping step, the stator core having the winding portion wound with the stator winding is rotated around the central axis in a posture in which the central axis is inclined with respect to the horizontal, while the upper part of the winding portion is inclined. Drop varnish on In the diffusion step, the dropping of the varnish is stopped, and the dropped varnish is diffused into the winding portion while rotating the stator core around the central axis in a posture where the central axis is returned to the horizontal.

  The varnish impregnation is performed by repeating a combination of a dropping step of dropping the varnish and a diffusion step of stopping the dropping of the varnish a plurality of times. In the diffusion process in which the dropping of the varnish is stopped, which is performed during the dropping process, the stator core is returned to the horizontal posture and rotated. For this reason, it is possible to infiltrate the varnish into a portion that is difficult to permeate while suppressing dripping of the varnish from the portion opposite to the portion where the varnish is dripped, that is, the inclined lower side of the winding portion. Therefore, it is possible to reduce the work for removing the varnish adhering to the stator core after curing the varnish, simplify the series of work for impregnating the varnish, and improve the efficiency of the varnish impregnation work.

It is a schematic block diagram which shows the varnish impregnation apparatus which actualized the varnish impregnation method of the stator core which concerns on this invention. It is an expanded sectional view showing a part of stator core. FIG. 3A is a conceptual diagram showing the state of the dropping step, and FIG. 3B is a conceptual diagram showing the state of the diffusion step.

  Embodiments of the present invention will be described below with reference to the drawings.

  Referring to FIG. 1, a varnish impregnation apparatus 100 includes a holding jig 110 capable of holding and releasing a stator core 10 including a winding portion 12 around which a stator winding 11 (see FIG. 2) is wound, that is, a coil. An inclination driving unit 120 that can move the jig 110 between a horizontal state and an inclined state, a rotation driving unit 130 that rotationally drives the holding jig 110, a dropping nozzle 140 that drops the varnish 40, and the holding jig 110. , An inclination driving unit 120, a rotation driving unit 130, and a controller 150 that controls the operation of the dropping nozzle 140.

  Referring to FIG. 2, stator core 10 is attached to ring-shaped housing 20. A circulation path 21 through which cooling water for cooling the stator core 10 flows is formed in the housing 20. In the illustrated winding portion 12, the stator winding 11 is wound by concentrated winding. The concentrated winding is a structure in which the stator winding 11 is directly wound around the insulating component 30 after assembling the resin insulating component 30 around the stator core 10. The winding portion 12 to which concentrated winding is applied can be reduced in size because the stator winding 11 hardly protrudes from the insulating component 30.

  In addition, this invention is applicable also to a stator core provided with the coil | winding part which wound the stator winding by distributed winding. Here, the distributed winding is a structure in which after a resin insulating part is inserted into the stator core, a winding portion wound in a ring shape in advance is inserted into the stator core. In the winding portion to which the distributed winding is applied, the stator winding greatly protrudes from the stator core as compared with the case where the concentrated winding is applied.

  The holding jig 110 has a holding portion 111 that is inserted into the center hole 10a of the stator core 10 and that can expand and contract in the radial direction. The holding part 111 holds the stator core 10 by expanding outward in the radial direction and press-contacting the inner peripheral surface of the center hole 10a. The holding part 111 contracts radially inward and releases the holding of the stator core 10 by moving away from the inner peripheral surface of the center hole 10a.

  The tilt drive unit 120 is constituted by a robot hand 121, for example. A holding jig 110 is attached to the tip of the hand. By operating the robot hand 121, the holding jig 110 moves between a horizontal state and an inclined state. By moving the holding jig 110 in this manner, the stator core 10 held by the holding jig 110 has an attitude in which the central axis O is inclined with respect to the horizontal, and an attitude in which the central axis O is horizontal. Move between. The inclination angle θ for inclining the central axis O with respect to the horizontal is not particularly limited, but is, for example, 5 to 20 degrees. In the following description, a posture in which the central axis O of the stator core 10 is inclined with respect to the horizontal is also referred to as an “inclined posture”, and a posture in which the central axis O of the stator core 10 is horizontal is also referred to as a “horizontal posture”.

  The rotation drive unit 130 is constituted by a motor 131, for example. The holding jig 110 is connected to the motor output shaft 132. By operating the motor 131, the holding jig 110 rotates, and the stator core 10 held by the holding jig 110 rotates. The speed VR1 for rotating the stator core 10 when the varnish 40 is dropped is related to the dropping speed and amount of the varnish, the size of the stator core, and the like, and is not particularly limited (for example, 10 rpm).

  The nozzle configuration of the dropping nozzle 140 is not particularly limited as long as the varnish 40 can be dropped toward the winding portion 12. The dripping nozzle 140 is connected to a liquid feed pump 142 that sends out the varnish 40 stored in the tank 141 via a pipe 143. The dropping nozzle 140 has an opening / closing valve 144 for opening / closing the nozzle 140. The varnish 40 is dripped by opening the on-off valve 144, and the dripping of the varnish 40 is stopped by closing the on-off valve 144.

  The controller 150 is mainly composed of a CPU and a memory, and outputs a control signal for controlling the operation to each of the holding jig 110, the robot hand 121, the motor 131, and the on-off valve 144. The controller 150 controls the expansion and contraction of the holding portion 111 in the holding jig 110 to hold and release the stator core 10. The controller 150 controls the operation of the robot hand 121 and determines the posture (tilted posture or horizontal posture) of the stator core 10 held by the holding jig 110. The controller 150 controls the operation of the motor 131 to rotate the stator core 10 held by the holding jig 110, change the rotation speed, change the rotation, and stop the rotation. The controller 150 controls the operation of the on-off valve 144 of the dropping nozzle 140 to drop and stop the varnish 40.

  Next, the operation of this embodiment will be described.

  The insulation treatment of the stator winding 11 is carried out through a preheating process of the stator core 10 in the heating furnace, an impregnation process of the varnish 40, a drying process of the varnish 40 in the drying furnace, and a cooling process of the stator core 10. Since each process of preheating, drying, and cooling can be implemented by a well-known method, explanation is omitted.

  The impregnation step of the varnish 40 in the present embodiment includes a dropping step of dropping the varnish 40 onto the winding portion 12 and a diffusion step of diffusing the dropped varnish 40 into the winding portion 12. The winding portion 12 of the stator core 10 is impregnated with the varnish 40 by repeatedly performing a combination of the dropping step and the diffusion step a plurality of times.

  Referring to FIG. 3A, in the dropping step, the stator core 10 including the winding portion 12 around which the stator winding 11 is wound is placed in a posture in which the central axis O is inclined with respect to the horizontal. The varnish 40 is dripped at the inclined upper part 12a side of the winding part 12 while rotating around.

  Referring to FIG. 3B, in the diffusion step, the dropping of varnish 40 is stopped, and the stator core 10 is dropped while rotating around the central axis O in a posture in which the central axis O is returned to the horizontal. The varnish 40 thus formed is diffused into the winding portion 12. The speed VR2 for rotating the stator core 10 around the central axis O in the diffusion process is set to be higher than the speed VR1 for rotating the stator core 10 around the central axis O in the dropping process (VR2> VR1).

  More specifically, in the dropping step, the controller 150 controls the expansion of the holding portion 111 in the holding jig 110 and holds the stator core 10 on the holding jig 110. The controller 150 controls the operation of the robot hand 121 so that the stator core 10 held by the holding jig 110 is inclined. The inclination angle θ is, for example, 5 to 20 degrees. By inclining the stator core 10, the varnish 40 can be easily dropped onto the winding portion 12 to which concentrated winding in which the stator winding 11 hardly protrudes from the insulating component 30 is applied. The controller 150 controls the operation of the motor 131 and rotates the stator core 10 held by the holding jig 110. The rotational speed VR1 of the stator core 10 is, for example, 10 rpm. The controller 150 controls the operation of the nozzle on-off valve 144 to open the on-off valve 144 and drop the varnish 40. The varnish 40 dripped onto the inclined upper part 12a side of the winding part 12 penetrates toward the inclined lower part 12b side of the winding part 12 by capillary action and its own weight. Further, as the stator core 10 rotates, the dropped varnish 40 spreads over the entire winding portion 12.

  In the diffusion step, the controller 150 controls the operation of the on-off valve 144 of the nozzle, closes the on-off valve 144, and stops the dripping of the varnish 40. The controller 150 controls the operation of the robot hand 121 to bring the stator core 10 into a horizontal posture. The controller 150 controls the operation of the motor 131 and increases the rotational speed of the stator core 10. The rate of increase of the rotational speed is not particularly limited, and can be appropriately changed depending on the size of the stator core 10, the diameter and winding method of the stator winding 11 (concentrated winding or distributed winding), the viscosity of the varnish 40 to be used, and the like. For example, the rotation speed VR2 of the stator core 10 in the diffusion process may be set to a speed that is about 1.3 times the rotation speed VR1 (for example, 10 rpm) in the dropping process. Either the form in which the rotational speed of the stator core 10 is increased while moving the stator core 10 from the inclined position to the horizontal position, or the form in which the rotational speed of the stator core 10 is increased after the stator core 10 is moved to the horizontal position may be used. Alternatively, the motor 131 may be temporarily stopped when the stator core 10 is moved to the horizontal posture.

  When shifting from the diffusion process to the next dropping process, the rotational speed of the stator core 10 is returned to the original rotational speed VR1 (for example, 10 rpm).

  When the combination of the dropping step and the diffusing step is repeated a plurality of times and the dropping of the predetermined amount of varnish 40 is completed, the process proceeds to the drying step. The number of repetitions of the combination of the dropping step and the diffusion step, the dropping amount of the varnish 40 in each of the repeated dropping steps (which may be the same or different amount), the total input amount of the varnish 40, etc. are not particularly limited, and are described above. Similarly to the above, it can be appropriately changed depending on the size of the stator core 10 and the like.

  In this embodiment, the varnish 40 is impregnated by repeating a combination of a dropping step of dropping the varnish 40 and a diffusion step of stopping the dropping of the varnish 40 a plurality of times. In the diffusion process in which the dropping of the varnish 40 is suspended, which is performed during the dropping process, the stator core 10 is returned to the horizontal posture and rotated. For this reason, it is possible to infiltrate the varnish 40 into a portion that is difficult to permeate while suppressing dripping of the varnish 40 from the portion opposite to the portion where the varnish 40 is dropped, that is, the portion on the inclined lower portion 12b side of the winding portion 12. it can. Therefore, it is possible to reduce the work of removing the varnish 40 attached to the stator core 10 after the varnish is cured, to simplify the series of work for impregnating the varnish 40, and to improve the efficiency of the varnish impregnation work.

  Moreover, in the diffusion process, the rotational speed of the stator core 10 is increased. For this reason, the penetration of the varnish 40 to the side that is difficult to penetrate, that is, the slot bottom 31 (see FIG. 2) of the stator core 10 can be promoted by centrifugal force. The varnish 40 sufficiently penetrates between the winding portion 12 and the insulating component 30 (outer diameter side) and between the insulating component 30 and the stator core 10 (inner diameter side). The gap between the stator windings 11, the gap between the winding portion 12 and the insulating component 30, and the gap between the insulating component 30 and the stator core 10 are filled with the varnish 40. Heat filling can be improved by filling the varnish 40 with a gap that greatly affects the thermal performance. Therefore, the heat generated in the stator winding 11 with energization is transferred to the varnish 40, the insulating component 30, the stator core 10, and the housing 20, and efficiently removed through the cooling water in the circulation path 21. Can do.

  The dropping amount of the varnish 40 in the dropping step, the rotational speed VR1 of the stator core 10, the rotational speed VR2 of the stator core 10 in the diffusion step, and the total input amount of the varnish 40 may be repeated multiple times by combining the dropping step and the diffusion step multiple times. It is desirable to determine the amount of drooping from the portion of the winding portion 12 on the inclined lower portion 12b side to a minimum, preferably zero. This is because the work of removing the varnish 40 attached to the stator core 10 after the varnish is cured can be minimized or eliminated, and the efficiency of the varnish impregnation work can be further improved.

10 stator core,
10a The center hole of the stator core,
11 Stator winding,
12 winding part,
12a Inclined upper part,
12b Lower slope,
20 housing,
21 circuit,
30 Insulating parts,
40 Varnish,
100 Varnish impregnation device,
110 holding jig,
111 holding part,
120 tilt drive,
121 robot hand,
130 rotational drive,
131 motor,
140 dripping nozzle,
144 On-off valve,
150 controller,
O The central axis of the stator core,
VR1 rotational speed of the stator core in the dropping step,
VR2 The rotational speed of the stator core in the diffusion process.

Claims (3)

A stator core having a winding portion wound with a stator winding is rotated around the central axis in a posture in which the central axis is inclined with respect to the horizontal, and a varnish is provided on the inclined upper side of the winding portion. A dropping step of dropping;
A diffusion step of diffusing the dropped varnish into the winding part while stopping the dripping of the varnish and rotating the stator core around the central axis in a posture in which the central axis is returned to the horizontal. ,
A stator core varnish impregnation method in which the winding portion of the stator core is impregnated with varnish by performing the dropping step and the diffusion step in combination.   The stator core varnish impregnation method according to claim 1, wherein the winding portion of the stator core is impregnated with varnish by repeatedly performing the combination of the dropping step and the diffusion step a plurality of times.   3. The stator core according to claim 1, wherein a speed of rotating the stator core around the central axis in the diffusion step is faster than a speed of rotating the stator core around the central axis in the dropping step. Varnish impregnation method.

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