阅读说明：本技术 电机线圈及其制备方法 (Motor coil and preparation method thereof ) 是由 邓凌曲 张露 郭伟 吕旭东 蔡军菲 于 2021-07-07 设计创作，主要内容包括：本申请公开了一种电机线圈及其制备方法,本申请的电机线圈由制备方法制得,其中制备方法包括喂料制备：将铜粉与粘结剂混合制成喂料；注射成型：将喂料通过注射机成型为生胚；脱除粘剂：将生胚置入脱脂炉中脱出粘结剂；烧结成型：将脱出粘结剂的生胚置入烧结炉中进行致密烧结。本申请的有益之处在于提供一种可以通过制备方式提高槽满率的电机线圈及其制备方法。(The application discloses a motor coil and a preparation method thereof, the motor coil is prepared by the preparation method, wherein the preparation method comprises the following steps: mixing copper powder and a binder to prepare a feed material; injection molding: molding the feed material into a green body by an injection machine; removing the adhesive: placing the green blank into a degreasing furnace to remove the binder; sintering and forming: and placing the green blank from which the binder is removed into a sintering furnace for dense sintering. The motor coil and the preparation method thereof have the beneficial effects that the slot fullness rate can be improved through the preparation mode.)

1. A preparation method of a motor coil is characterized by comprising the following steps:

the preparation method comprises the following steps:

preparing a feed: mixing copper powder and a binder to prepare a feed material;

injection molding: molding the feed material into a green body by an injection machine;

removing the adhesive: placing the green blank into a degreasing furnace to remove the binder;

sintering and forming: and placing the green blank from which the binder is removed into a sintering furnace for dense sintering.

2. The method for manufacturing a coil for an electric machine according to claim 1, wherein:

the granularity of the copper powder is less than or equal to 30 microns, and the oxygen content is less than 0.05 percent.

3. The method for manufacturing a coil for an electric machine according to claim 1, wherein:

the binder comprises POM.

4. The method for manufacturing a coil for an electric machine according to claim 1, wherein:

the binder comprises polyethylene glycol.

5. The method for manufacturing a coil for an electric machine according to claim 1, wherein:

the binder comprises stearic acid.

6. The method for manufacturing a coil for an electric machine according to claim 1, wherein:

the volume ratio of the copper powder to the binder ranges from 0.55 to 0.65.

7. The method for manufacturing a coil for an electric machine according to claim 1, wherein:

the processing time of the green embryo in the degreasing furnace ranges from 1 hour to 4 hours.

8. The method for manufacturing a coil for an electric machine according to claim 1, wherein:

the processing time of the green body in the sintering furnace ranges from 7 hours to 12 hours.

9. The method for manufacturing a coil for an electric machine according to claim 1, wherein:

the feeding speed of the injection machine is in a value range of 9cm³S to 12cm³/s。

10. An electric machine coil produced by the production method according to any one of claims 1 to 9.

Technical Field

The application relates to a motor coil and a preparation method thereof.

Background

The traditional motor coil is formed by winding a round wire with a uniform section or a flat wire with a uniform section. This tends to have the problem of a low slot fill ratio, which affects the torque density and power density of the motor.

Disclosure of Invention

A method for preparing a coil of an electric machine, comprising: preparing a feed: mixing copper powder and a binder to prepare a feed material; injection molding: molding the feed material into a green body by an injection machine; removing the adhesive: placing the green blank into a degreasing furnace to remove the binder; sintering and forming: and placing the green blank from which the binder is removed into a sintering furnace for dense sintering.

Further, the particle size of the copper powder is less than or equal to 10 microns.

Further, the binder comprises POM.

Further, the binder includes polyethylene glycol.

Further, the binder comprises stearic acid.

Further, the volume ratio of the copper powder to the binder ranges from 0.55 to 0.65.

Further, the processing time of the green embryo in the degreasing furnace ranges from 1 hour to 4 hours.

Further, the processing time of the green body in the sintering furnace ranges from 7 hours to 12 hours.

Further, the feeding speed of the injection machine is in a value range of 9cm³S to 12cm³/s。

As another aspect of the present application, the present application also provides an electric machine coil prepared by the preparation method as described above.

The application has the advantages that: provided are a motor coil and a method for manufacturing the same, which can improve a slot filling factor by a manufacturing method.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, serve to provide a further understanding of the application and to enable other features, objects, and advantages of the application to be more apparent. The drawings and their description illustrate the embodiments of the invention and do not limit it. In the drawings:

FIG. 1 is a schematic diagram of a structure of a motor coil according to an embodiment of the present application;

FIG. 2 is a schematic view of a mold used in the preparation according to one embodiment of the present application;

FIG. 3 is a block diagram illustrating steps of a method of making according to one embodiment of the present application.

Detailed Description

In order to make the technical solutions better understood by those skilled in the art, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only partial embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

It should be noted that the terms "first," "second," and the like in the description and claims of this application and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It should be understood that the data so used may be interchanged under appropriate circumstances such that embodiments of the application described herein may be used. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present application will be described in detail below with reference to the embodiments with reference to the attached drawings.

The preparation method of the motor coil comprises the following steps: preparing a feed: mixing copper powder and a binder to prepare a feed material; injection molding: molding the feed material into a green body by an injection machine; removing the adhesive: placing the green blank into a degreasing furnace to remove the binder; sintering and forming: and placing the green blank from which the binder is removed into a sintering furnace for dense sintering.

Specifically, the particle size of the copper powder is 30 μm or less.

Specifically, the binder comprises POM.

Specifically, the binder includes polyethylene glycol.

Specifically, the binder comprises stearic acid.

Specifically, the mass ratio of the copper powder to the binder ranges from 1.5 to 9. Alternatively, the volume ratio of copper powder to binder ranges from 0.55 to 0.65.

Specifically, the processing time of the green embryo in the degreasing furnace ranges from 1 hour to 4 hours. Catalytic degreasing is adopted, wherein the degreasing temperature range is concentrated at 120 ℃ to 180 ℃ and the time is 1 to 4 hours.

As a specific scheme, catalytic degreasing is adopted, wherein the degreasing temperature ranges from 120 ℃ to 180 ℃ and the time is 1-4 h. The degreasing time is 1 to 4 hours according to the degreasing efficiency of 1 mm/hour according to the thickness of the product. The degreasing temperature is 160 to 200 ℃. The two-stage catalytic degreasing temperature is 110-145 ℃ and 160-190 ℃ by using anhydrous oxalic acid, when the minimum degreasing rate of the green embryo reaches 9.4 percent, the degreasing process can be stopped, and the green embryo is not suitable to be placed for too long after degreasing. It should be noted that the oxygen content in the furnace chamber during the degreasing process cannot be higher than 4.5% (volume fraction), and explosion may occur beyond this limit; because the blank body after degreasing is easy to absorb the moisture in the air, the degreasing rate is not recommended to judge whether the degreasing process is finished, and the product is preferably free of POM interlayer.

And a corundum support is used during degreasing, so that the coil is prevented from collapsing and deforming in the degreasing process. When the degreasing rate is 7-9%, the whole coil to be sintered is stably and quickly transferred to a sintering furnace. The degreased product enters a sintering furnace through specific jig positioning and fixing (including ceramic jig, complete embedding and fixing and other methods) to ensure the structure and size of the product in the sintering process.

Specifically, the processing time of the green body in the sintering furnace ranges from 7 hours to 12 hours.

Sintering in a hydrogen protective atmosphere, heating to 300 ℃ at a heating rate of 3 ℃/min, and keeping the temperature for 1 h; heating to 500 ℃ at the heating rate of 3 ℃/min and preserving heat for 1 h; heating to 600 ℃ at the speed of 3 ℃/min and preserving heat for 1 h; heating to 700 ℃ at the heating rate of 3 ℃/min and preserving heat for 1 h; heating to 800 ℃ at the heating rate of 3 ℃/min, keeping the temperature for 1h, heating to 900 ℃ at the heating rate of 3 ℃/min, keeping the temperature for 2h, heating to 1050 ℃ at the heating rate of 5 ℃/min, keeping the temperature for 2h, and then cooling along with the furnace.

More specifically, the temperature is raised at a constant temperature raising rate, for example, 3 ℃/min; heating up to the designated temperature in sections, preserving heat, continuously realizing stable heating up and preserving heat processes, and finally setting the temperature processing time to be 10-24 hours and the maximum sintering temperature to be 1030-1050 ℃. The typical sintering period is that the temperature is raised from room temperature to 600 ℃ at 5 ℃/min and is kept for 60 minutes, then is raised to 1050 ℃ at 5 ℃/min and is kept for 180 minutes, and then the sintering is carried out in a furnace cooling and hydrogen protective atmosphere.

Specifically, the feeding speed of the injection machine is in a value range of 9cm³S to 12cm³/s。

Heating at a certain heating rate, for example, 3 ℃/min; heating up to the designated temperature in sections, preserving heat, continuously realizing stable heating up and preserving heat processes, and finally setting the temperature processing time to be 10-24 hours and the maximum sintering temperature to be 1030-1050 ℃. A typical sintering cycle is from room temperature at 5 ℃ per minute to 600 ℃, held at 60 minutes, and then increased at 5 ℃ per minute to 1050 ℃ C

Specifically, the feeding speed of the injection machine is in a value range of 9cm³S to 12cm³/s。

As another aspect of the present application, the present application also provides an electric machine coil prepared by the preparation method as described above.

The method can be used for manufacturing a motor coil with a complex shape to obtain a variable-section flat wire (in order to minimize the resistance of the coil, the area of copper is kept constant in each coil) molding winding, the winding coil can fully utilize the space in an iron core slot, and compared with the traditional round wire coil winding, the method can greatly improve the slot filling rate, thereby improving the torque density and the power density of the motor; in addition, according to the powder injection molding process, the layer height of each turn of the coil can be close to 0.6mm, and the wire loss caused by eddy current can be effectively reduced; the coil is most suitable for use in an electrical machine with concentrated windings, and short end windings can be achieved due to the absence of bend radii.

The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.