Motor device manufacturing method

Abstract

To provide a motor device manufacturing method which can be performed at a low cost and by which a core can be fixed while iron loss is suppressed.SOLUTION: A manufacturing method for a motor device including a plurality of split cores 21 to 24 (see FIG. 1) each formed by layering a plurality of electromagnetic steel sheets 31 (see FIG. 1), and an outer tubular ring 12 that has a tubular shape and fixes, on the inner circumferential side thereof, the plurality of split cores 21 to 24. In a case where the split cores 21 to 24 are combined to form one core 11, the outer tubular ring 12 is formed to be longer than the core 11 in an axis direction which is the layered direction of the electromagnetic steel sheets 31. The method includes the steps of forming the one core 11 by arranging the split cores 21 to 24 on the inner circumference of the outer tubular ring 12, and heating an end of the outer tubular ring 12 protruding, in the axis direction, from the electromagnetic steel sheets 31 arranged at an end of the core 11.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a method for manufacturing a motor device. [Background technology]

[0002] In recent years, motor devices have been using split cores in which each core is formed separately and assembled to form the original circular shape. This core is made of laminated electromagnetic steel sheets, and this core can achieve low magnetic flux loss by passing magnetic flux along the rolling direction of the laminated electromagnetic steel sheets. Here, in order to pass magnetic flux along the rolling direction of the laminated electromagnetic steel sheets, it is necessary to align the direction of magnetic flux with the rolling direction of the electromagnetic steel sheets, and to achieve this state, it is necessary to split the core. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2013-055723 A Summary of the Invention [Problem to be solved by the invention]

[0004] When using split cores as a core, the split cores need to be fastened together. Ideally, it would be desirable to weld the split cores together, but if the magnetic steel sheets become conductive and the insulating coating is removed, the eddy magnetic flux disappears and eddy loss increases.

[0005] For this reason, a method is known in which the split cores are fixed in a circular arrangement by shrink-fitting them while the split cores are stored inside a separate part called an outer cylinder ring. However, there are problems in that the insulating coating of the electromagnetic steel sheet is thermally affected by the high temperature during shrink-fitting, and that it is difficult to control the tightening margin. The tightening margin is determined by multiplying the Young's modulus by the temperature difference before and after shrink-fitting, but it is necessary to control the temperature of the entire product and equipment. For example, in summer, the room temperature is high, so there is a risk that the tightening margin will be insufficient, and conversely, in winter, there is a risk that the tightening margin will be too high, resulting in large iron loss in the core.

[0006] On the other hand, when fixing the core using an outer ring, the core will not come off the outer ring even if only the electromagnetic steel sheets arranged at the end of the laminated electromagnetic steel sheets are fixed. Therefore, there is a waste of heating in shrink fitting that heats the entire outer ring. Furthermore, there is a problem that applying excessive stress to the electromagnetic steel sheets increases iron loss.

[0007] The present disclosure provides a manufacturing method for a motor device that can be implemented at low cost and that can fix the core in a state where iron loss is suppressed. [Means for solving the problem]

[0008] The manufacturing method of a motor device according to the present disclosure is a manufacturing method of a motor device having a plurality of split cores, each formed by stacking a plurality of electromagnetic steel plates, and a cylindrical outer cylindrical ring that fixes the plurality of split cores on its inner side, wherein the outer cylindrical ring is formed to be longer than the core in the axial direction, which is the stacking direction of the electromagnetic steel plates, when the plurality of split cores are combined to form a single core, and includes a step of arranging the plurality of split cores on the inner circumference of the outer cylindrical ring to form the single core, and a step of heating an end of the outer cylindrical ring that protrudes from the electromagnetic steel plates arranged at the end of the core in the axial direction. With this, when the end of the outer cylindrical ring is heated, this end falls in the inner radial direction, thereby fixing the core disposed on the inner circumference of the outer cylindrical ring. Effect of the Invention

[0009] According to the present disclosure, it is possible to provide a manufacturing method for a motor device that can be implemented at low cost and that can fix the core in a state where iron loss is suppressed. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram of a motor device according to the present disclosure. [Diagram 2] 5A to 5C are diagrams illustrating a flow of a manufacturing method for a motor device according to the present disclosure. [Diagram 3] 1 is a diagram of a motor device in which both the top and bottom of an outer cylindrical ring according to the present disclosure are reduced in diameter. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] First embodiment Hereinafter, a motor device according to this embodiment will be described with reference to the drawings. Fig. 1 shows an example of the configuration of a motor device 1, with Fig. 1(a) being a top view of the motor device 1 and Fig. 1(b) being a cross-sectional view of the motor device 1 as viewed from the side. Fig. 1(c) is a cross-sectional view of an example of a state in which a lower portion of the motor device 1, which will be described later, is fixed to a TA case 2 as viewed from the side.

[0012] The motor device 1 includes a core 11 and an outer cylindrical ring 12 that has the core 11 disposed on its inner circumference. As shown in Fig. 1(a) and Fig. 1(b), the axial direction, which is the lamination direction of the laminated steel plates that form the core 11, is the up-down direction (Z direction), and the radial directions of the core 11 and the outer cylindrical ring 12 are the XY directions. The X direction, Y direction, and Z direction are mutually perpendicular, and the X direction and Y direction are horizontal. In the following, the up-down direction may be referred to as height.

[0013] Core 11 is composed of a combination of a plurality of split cores. For example, the split cores constituting core 11 will be described as split cores 21 to 24. Core 11 is composed of split cores 21 to 24 combined. In the following description, it is assumed that core 11 has a diameter of 240 mm.

[0014] Here, each of the split cores 21-24 is formed from electromagnetic steel sheets 31 laminated in the axial direction. Thus, core 11 formed by combining split cores 21-24 is also formed by laminating electromagnetic steel sheets 31. Of the axial ends of core 11, the end that is disposed on the upper side during use will be described as upper end 11a, and the end that is disposed on the lower side will be described as lower end 11b.

[0015] The outer cylindrical ring 12 is cylindrical and fixes the multiple cores on the inner periphery side, and when the split cores 21-24 are combined to form one core 11, it is formed to be longer than the core 11 in the axial direction, which is the lamination direction of the electromagnetic steel sheets 31. Of the ends of the outer cylindrical ring 12 in the axial direction, the end that is arranged on the upper side during use will be described as upper end 12a, and the end that is arranged on the lower side will be described as lower end 12b.

[0016] 1(b) and 1(c), when the lower end 11b of the core 11 and the lower end 12b of the outer tubular ring 12 are arranged so that their heights are aligned, the upper end 12a of the outer tubular ring 12 is arranged above the upper end 11a of the core 11. In this way, the outer tubular ring 12 is formed to be longer than the core 11 in the axial direction, which is the lamination direction of the electromagnetic steel sheets 31 of the core 11, and protrudes above the upper end 11a of the core 11.

[0017] In the following description, the inner periphery of the outer cylindrical ring 12 is assumed to be 240 mm in diameter, and the circumferential length of the outer cylindrical ring 12 is 753.6 mm.

[0018] Furthermore, the outer tubular ring 12 has a sacrificial bead portion 41 formed along the circumferential direction on a part of the inner circumferential surface. Typically, the sacrificial bead portion 41 is formed extending in the circumferential direction on the inner circumference of the outer tubular ring 12 when the core 11 is disposed on the inner circumference of the outer tubular ring 12. Note that the sacrificial bead portion 41 shrinks when the upper end portion 12a of the outer tubular ring 12 is heated as described below.

[0019] Next, an example of a manufacturing method for the motor device 1 will be described with reference to Fig. 2. Fig. 2(a) to Fig. 2(c) are a top view and a cross-sectional view from a side of the motor device 1 illustrating the manufacturing process of the motor device 1. Note that in Fig. 2, the core 11 is considered to be a single core, and illustrations of the electromagnetic steel sheet 31 and the split cores 21 to 24 are omitted.

[0020] 2(a), the core 11 is inserted into the inner circumference of the outer cylindrical ring 12. Here, it is preferable that the inner diameter of the outer cylindrical ring 12 and the outer diameter of the core 11 are approximately the same length and that the clearance is small.

[0021] 2(b), the motor device 1 is turned upside down together with the outer tubular ring 12, and the upper end portion 12a of the outer tubular ring 12 disposed below is heated. Here, the motor device 1 is turned upside down in order to prevent spatter from adhering to the core 11 and causing rust when arc welding is performed to heat the upper end portion 12a.

[0022] Here, the arc welding may be any of TIG, MIG, and MAG, or may be by laser irradiation. That is, any welding method may be used as long as it is possible to heat the upper end portion 12a of the outer tubular ring 12, melt the sacrificial bead portion 41 once, and cool and shrink it. This heating is performed on a portion of the upper end portion 12a of the outer tubular ring 12 where heat is not transferred to the electromagnetic steel sheet 31 forming the core 11.

[0023] Here, Fig. 2(c) shows the motor device 1 turned upside down again from the state shown in Fig. 2(b) so that the motor device 1 is in its original state. As shown in Fig. 2(c), in the outer tubular ring 12, the sacrificial bead portion 41 shrinks due to heating, so that the upper end portion 12a falls toward the inner diameter side. At this time, the unheated portion of the upper end portion 12a also falls due to misalignment.

[0024] Specifically, the outer cylindrical ring 12 is shrunk by 0.75 mm in the circumferential direction due to welding, and is shrunk by 0.24 mm in the radial direction, with the upper end portion 12a leaning toward the inner diameter side.

[0025] At this time, the collapse of the upper end portion 12a of the outer cylindrical ring 12 propagates to the core 11, and compressive stress is generated from the outer cylindrical ring 12 toward the core 11. The core 11 receives this compressive stress from the outer cylindrical ring 12 and is fixed between the outer cylindrical ring 12, and the split cores 21-24 are also fixed to each other.

[0026] In this manner, by melting one end side of the outer tubular ring 12 and causing it to thermally shrink, this end side falls toward the inner diameter side, thereby fixing the split cores 21 to 24. In other words, as the upper end 12a of the outer tubular ring 12 is heated, the upper end 12a side falls toward the inner diameter side, thereby fixing the core 11 disposed on the inner circumference of the outer tubular ring 12.

[0027] Therefore, it is possible to provide a manufacturing method for a motor device that can be implemented at low cost and that can fix the core in a state where iron loss is suppressed.

[0028] In addition, it is more preferable to use arc welding such as TIG to heat the upper end 12a of the outer tubular ring 12 than laser welding, which reduces the amount of melting of the sacrificial bead portion 41. However, since the upper end 12a of the outer tubular ring 12 becomes hot, it is necessary to weld a portion sufficiently away from the upper end 11a of the core 11 so that the heat does not propagate to the core 11. As an example, the insulating coating of the electromagnetic steel sheet 31 of the core 11 can withstand temperatures up to about 200°C, so it is sufficient to heat the upper end 12a of the outer tubular ring 12 without exceeding this temperature.

[0029] Furthermore, in the outer tubular ring 12, the greater the melting amount of the sacrificial bead portion 41, the greater the fixing force generated for the core 11. Therefore, the worker can adjust the penetration depth of the arc welding based on the magnitude of the fixing force required from the outer tubular ring 12 to the core 11. The same can be said for adjusting the magnitude of the voltage and current applied to the arc welding, and the worker can adjust the voltage and current to achieve optimal welding conditions based on the magnitude of the fixing force required.

[0030] In Figures 1 and 2, the sacrificial bead portion 41 is described as being provided long in the vertical direction from the upper end portion 12a of the outer tubular ring 12 to the upper end portion 11a of the core 11, but the arrangement of the sacrificial bead portion 41 is not limited to this.

[0031] For example, if a small fixing force is acceptable, the sacrificial bead portion 41 may be provided with a limited length, such as 120° out of 360° of the inner circumference, and the diameter may be reduced by welding. In the extreme case, when the sacrificial bead portion 41 is used to reduce the diameter of the outer tubular ring 12, it is also possible to use only spot welding.

[0032] The present invention is not limited to the above-described embodiment, and can be modified as appropriate without departing from the spirit of the present invention. In other words, the above description has been omitted or simplified as appropriate for the purpose of clarity, and a person skilled in the art can easily modify, add, or convert each element of the embodiment within the scope of the present invention.

[0033] In FIG. 2, it has been described that only the upper end portion 12a of the outer tubular ring 12 is heated to shrink it in the inner diameter direction, but as shown in FIG. 3, it is also possible to heat both the upper end portion 12a and the lower end portion 12b of the outer tubular ring 12 to shrink them in the inner diameter direction.

[0034] In this case, the upper end 12a and the lower end 12b of the outer cylindrical ring 12 are welded together, and the welded outer cylindrical ring 12 is press-fitted into an aluminum die-cast TA case 2. Furthermore, the outer cylindrical ring 12 is filled with resin and wrapped in resin, and can be used as a motor device.

[0035] For the split cores 21-24, a clamping margin of about 5-10 μm is sufficient, but it is possible that a greater fixing force is required depending on the size of the core or the magnitude of motor vibration, in which case measures can be taken such as increasing the clamping margin. The clamping margin may be an interference fit or an intermediate fit, and can be freely changed depending on the product.

[0036] In addition, although the description has been given of a single core 11 formed by combining the split cores 21-24 and placing them inside the outer cylindrical ring 12, and then fixing the core 11 by heating the outer cylindrical ring 12, the core 11 may be a single core rather than a split core. [Explanation of symbols]

[0037] 1 Motor device 2 TA case 11 cores 12 Outer cylinder ring 21~24 Split core 31 Electrical steel sheet 41 Temporary bead

Claims

[Claim 1] A method for manufacturing a motor device having a plurality of split cores, each of which is formed by laminating a plurality of electromagnetic steel sheets, and a cylindrical outer cylindrical ring that fixes the plurality of split cores on an inner peripheral side, comprising: When the plurality of split cores are combined to form one core, the outer cylindrical ring is formed longer than the core in an axial direction which is a lamination direction of the electromagnetic steel sheets, a step of forming one core by arranging the plurality of split cores on an inner periphery of the outer cylindrical ring; and heating an end of the outer cylindrical ring protruding from an electromagnetic steel plate disposed at an end of the core in the axial direction. A method for manufacturing a motor device.

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