JPS6349465B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a brushless motor having a structure that has good performance and is easy to manufacture, and a method for manufacturing the same.

Conventional brushless motors have slots formed in the stator core to house the windings, which causes cogging and uneven rotation.

This effect is particularly noticeable during low speed operation, and is extremely inconvenient when the speed change range extends to a low speed range or when used as a motor for precise position control.

On the other hand, in terms of manufacturing, the stator core is formed by punching and forming steel plates, which results in poor material utilization, expensive punching dies, and difficulty in constructing small-diameter motors due to the need to accommodate the windings. I had a problem.

In addition, coreless motors that improve these drawbacks have low reliability because they use brushes, and are said to be highly reliable only to the extent that they do not cause problems due to troubles with the brushes.

SUMMARY OF THE INVENTION Under these circumstances, it is an object of the present invention to provide a brushless motor that solves these problems, is highly efficient, highly reliable, and easy to manufacture, and a method for manufacturing the same.

The present invention will be explained below based on an embodiment shown in the drawings. Fig. 1 is a longitudinal sectional view of a brushless motor according to an embodiment of the present invention, and Fig. 2 shows a cylindrical coil wound around a mold. A perspective view showing a state in which the
FIG. 3 is a perspective view showing a state in which iron wire is wound around the cylindrical coil shown in FIG. 2, and FIG. 4 is a longitudinal cross-sectional view showing a state in which the cylindrical coil shown in FIG. 2 is housed in a mold.

In the brushless motor shown in FIG. 1, a stator is formed by winding iron wire 2 around the outer periphery of a cylindrical coil 1, and the outside is molded with resin 3.

A rotor 4 made of permanent magnets is housed in the stator, and a shaft 5 of the rotor 4 is supported by brackets 6 and 7 provided at both ends of a frame made of resin 3 through bearings 8 and 9. .

Furthermore, a speed detector 10 made of a permanent magnet is provided on the shaft 5, and a position detector 11 made of a Hall element or the like is provided at a position facing the speed detector 10.

In FIG. 2, the cylindrical coil 1 is constructed by winding a magnet wire in the shape of a coil spring and making it flat by moving opposing sides relatively, and winding it around a mold 12.

The cylindrical coil 1 is constructed by applying varnish or an insulating and adhesive adhesive while being packaged in a mold 12.

Furthermore, the mold 12 has shafts 13 extending from both ends, and is configured to be rotated by power (not shown), and is configured such that a heater is formed internally or hollow so that thermal power can be applied to heat the mold 12. has been done.

In FIG. 3, a cylindrical coil 1 is wrapped in a mold 12 and wrapped with an iron wire 2 before a fixing agent such as varnish is hardened.

The iron wire 2 to be wound may be made of a magnetic material with good characteristics to obtain high efficiency, but sufficient characteristics can also be obtained by using a general wire.

In FIG. 4, a mold 12 having a cylindrical coil 1 and an iron wire 2 is placed in resin molds 14 and 15, and is configured so that resin 3 can be injected through a gate 16 to perform molding.

At this time, the mold 12 is configured to be used as a core of the molds 14 and 15, and
The cylindrical coil 1 is wrapped around the cylindrical coil 2 with a release agent 17 made of thermoplastic resin interposed therebetween.

Furthermore, the release agent 17 can be easily attached by forming a thermoplastic resin into a sheet shape, wrapping it around the mold 12 as appropriate, and then wrapping the cylindrical coil 1 on the outside. When extracting the cylindrical coil 1 from the mold 12, it can be heated and softened to facilitate mold removal, and when the softened release agent 17 hardens again, it hardens while entering the gap between the cylindrical coils 1. Can show holding power.

In this configuration, the brushless motor uses a cylindrical coil 1 in the stator, so there is no cogging, and even if the speed is controlled over a wide range of 100:1 to 1000:1, the speed can be changed without any problem, and it is also precise. It operates with high reliability even when used in industrial robots that perform precise position control.

On the other hand, in terms of production, the iron wire 2 can be used without any waste, and the iron wire 2 can be easily wound by rotating the mold 12, and if the iron wire 2 is wound in an orderly manner so that tension is applied to the iron wire 2 during winding, the iron wire 2 can be easily wound. It is possible to increase the winding density.

Then, due to the axial pressure caused by the winding of the iron wire 2, the cylindrical coil 1 is brought into close contact with the mold 12, resulting in good alignment, minimizing the gap with the rotor 4, and improving efficiency.

Moreover, since it can be manufactured in this manner, there is no problem in forming it long in the axial direction, and a structure that cannot be obtained with conventional motors can be obtained.

When winding the iron wire 2, if it collapses at the end, a bobbin with a collar may be used, or a jig may be used to secure the wire so that it does not collapse during winding.

If a fixing agent such as varnish is applied to the mold 12 after the cylindrical coil 1 is wrapped around the mold 12, and the iron wire 2 is wrapped before it dries, the undried varnish will not enter the gap between the iron wires 2 to be wrapped. The holding function of the cylindrical coil 1 can be configured.

Also, when packaging the cylindrical coil 1 in the mold 12,
If a thermoplastic release agent 17 is interposed and the mold 12 is heated in a post-process, the release agent 17 will soften and flow, allowing the mold 12 to be easily extracted from the cylindrical coil 1. .

Furthermore, when the resin 3 is injected into the molds 14 and 15 and molded, such a release agent 17 tends to fuse with the injected resin 3, resulting in an extremely good molding condition.

The release agent 17 is not necessarily limited to using thermoplastic resin or the like, but may be composed of a multilayer sheet and slid between the layers for the purpose of separating the cylindrical coil 1 and the mold 12. In this case, the cylindrical coil 1 may be connected to the iron wire 2 using another adhesive.

Since the mold 12 can be used as the core of the molds 14 and 15, it is possible to construct a frame with good alignment with respect to the cylindrical coil 1.

Since the brackets 6 and 7 can be formed with well-aligned spigots on the frame, they are easy to fit and can provide sturdy bearings with good alignment.

Therefore, even if the brushless motor is configured to have an elongated shape in the axial direction, it is possible to form an efficient brushless motor without causing problems such as contact with gaps.

In addition, when the iron wire 2 is wrapped, the outside becomes uneven and easily collapses due to external force, but if it is molded with the resin 3 using the mold 12 as a core, it can be made into any shape that is strong and does not require post-processing. It is extremely convenient to obtain a frame of

Then, when molding the resin 3, the position detector 11 is
By also embedding the position detector 11 in the mold 12, assembly man-hours can be eliminated and the installation can be performed reliably.

Further, when constructed by molding in this manner, the brushless motor is completed by assembling some parts such as the brackets 6 and 7 and the rotor 4, which is extremely convenient for assembly.

As explained above, according to the present invention, since a cylindrical coil is wound with iron wire, it is possible to construct a highly efficient brushless motor that is elongated and easy to assemble. By assembling the stator using available molds, precise assembly can be achieved in a very convenient manner, and this has great industrial effects.

[Brief explanation of drawings]

FIG. 1 is a vertical sectional view of a brushless motor according to an embodiment of the present invention, FIG. 2 is a needle perspective view showing a state in which a cylindrical coil is wound around a mold, and FIG. FIG. 4 is a perspective view showing a state in which iron wire is wound around a cylindrical coil, and FIG. 4 is a longitudinal sectional view showing a state in which the coil is housed in a mold. 1... Cylindrical coil, 2... Iron wire, 3... Resin,
4... Rotor, 12... Mold, 14, 15... Molding die.

Claims (1)

[Claims] 1. Magnet wire is wound into a spring shape, opposing sides are moved relative to each other to make it flat, and this is made into a cylindrical shape. Iron wire is wound around the outer periphery of a cylindrical coil using a bonding agent. A brushless motor with a fixed stator and a permanent magnet rotor inside. 2. A method for manufacturing a brushless motor, which comprises wrapping a cylindrical coil in a rotating mold, rotating it and wrapping it with iron wire. 3. A method for manufacturing a brushless motor according to claim 2, characterized in that a cylindrical coil wrapped around a rotating mold is fixed and wrapped with iron wire before hardening. 4. A method of manufacturing a brushless motor according to claim 2 or 3, characterized in that a rotating mold is used as a core and placed in a mold, and the stator is molded with resin. 5. The method of manufacturing a brushless motor according to claim 2, 3, or 4, characterized in that the rotating mold is sheathed with a cylindrical coil via a release agent. 6. The method of manufacturing a brushless motor according to claim 5, wherein a thermoplastic resin is used as the release agent and the rotary mold is configured to be heated.