JPH07308051A - Motor manufacturing method - Google Patents

Abstract

PURPOSE:To provide a motor manufacturing method by which the number of parts and processes is cut, cost is reduced, and reliability is improved. CONSTITUTION:A motor manufacturing method comprises a step for forming a rotor assembly 20 by outsert molding a magnet 34 and rotor bearing 36 to a rotor housing 30, step for forming a stator assembly 22 by outsert molding a stator bearing 44 to a stator base plate 40 and locating a coil assembly 42, and step for assembling the rotor assembly 20 and stator assembly 22 by providing a gap epsilon between the rotor bearing 36 and stator bearing 44 with lubricant 26 and ball 24 put between the rotor bearing 36 and stator bearing 44.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor manufacturing method, and more particularly to a so-called face-to-face motor manufacturing method.

[0002]

2. Description of the Related Art An information medium, for example, a magnetic recording medium such as a floppy disk (FD), an optical recording medium such as a compact disk (CD), or a magneto-optical recording medium such as a mini disk (MD) is rotated. Then, when recording information on this recording medium or reproducing information recorded on the recording medium, a spindle motor as shown in FIG. 9 is used.

The spindle motor shown in FIG. 9 has a rotor portion 1 and a stator portion 2. The rotor unit 1 has a magnet unit 3, a shaft 4, a chuck table unit 5 for chucking a recording medium, and a rotor housing 6. The shaft 4 is press-fitted into the rotor housing 6 of the rotor unit 1. The stator portion 2 has the coil 8 mounted on the chassis mounting portion 7 and the bearing 9 mounted thereon. The shaft 4 is inserted into the bearing 9, and the shaft 4 is inserted through the hard balls 10.
Is rotatable. The conventional motor shown in FIG. 9 is
This is a so-called face-to-face type motor in which the magnet portion 3 and the coil 8 are opposed to each other.

A method of manufacturing the conventional motor will be sequentially described with reference to FIGS. As shown in FIG. 10, the rotor housing 6 is manufactured by a sheet metal press (step 1). Next, as shown in FIG. 11, the shaft 4 is turned to manufacture (step 2). As shown in FIG. 12, a magnet part 3 is made by molding and magnetizing a plastic magnet (steps 3 and 4). As shown in FIG. 13, the chuck table portion 5 is molded (step 5).

Next, as shown in FIG. 14, the shaft 4 is press-fitted into the hole 6a of the rotor housing 6 (step 6). Then, the magnet portion 3 and the chuck table portion 5 are bonded to the rotor housing 6. As a result, the rotor portion 1 which is also called a rotor assembly can be manufactured (step 7).

On the other hand, as shown in FIG. 15, a chassis mounting portion 7 is made by sheet metal pressing (step 8). As shown in FIG. 16, the coil 8 is mounted on the chassis mounting portion 7 and other circuits are mounted (step 9).

Next, the bearing 9 is formed as shown in FIG. 17 (step 10). Then, as shown in FIG. 18, the bearing 9 is press-fitted or caulked in the hole 7a of the chassis mounting portion 7 to be mounted. As a result, the stator portion 2, which is also called a stator assembly, is formed (step 11). The rotor portion 1 and the stator portion 2 thus obtained are assembled as shown in FIG. That is, the hard balls 10 coated with lubricating oil are put in the bearings 9, the shaft 4 of the rotor part 1 is inserted into the bearings 9 of the stator part 2, and the hard balls 10 receive them. Coil 8
By energizing the rotor portion 1, the rotor portion 1 can rotate in the arrow R direction with respect to the stator portion 2 via the shaft 4.

[0008]

However, in this type of motor, recording / reproducing on a recording medium is stable in that the inclination of the surface of the chuck table portion 5, that is, the angle θ is small and is within an allowable range. Is necessary to realize. As described above, the following conditions are required in manufacturing in order to reduce the angle θ. Whether the rotor part 1 or the stator part 2 is made, it is necessary to maintain accuracy while assembling some parts, and therefore it is necessary to increase the accuracy of each component part.

Further, in the rotor part 1, it is necessary to press fit the shaft 4 into the rotor housing 6, and in the stator part 2 it is necessary to press fit or caulk the bearing 9 into the chassis mounting part 7. Moreover, in the rotor unit 1, it is necessary to bond the magnet unit 3 and the chuck table unit 5 to the rotor housing 6. In these processes, due to factors such as the skill of the operator and the accuracy of the jig, the press fitting, caulking or bonding accuracy is likely to change. For this reason, it is not easy to reduce the time required for processing or to secure the stable accuracy of a necessary portion, which is an obstacle to cost reduction. In addition, there is always a concern about quality variations.

By the way, in order to keep the angle θ of inclination of the surface of the chuck table 5 in FIG. 9 within a certain allowable range,
It is necessary to suppress the accuracy of parallelism a and squareness b. Six parts are involved in the accuracy of the parallelism a, and three steps are involved in the accuracy of the parallelism a. The parts involved in the accuracy of the parallelism a include the chassis mounting portion 7 of the stator portion 2, the bearing 9, the hard ball 10, the shaft 4, the rotor housing 6,
The six parts of the chuck table section 5. The steps involved in the accuracy of the parallelism a include the step of press-fitting or caulking the chassis mounting portion 7 and the bearing 9 of the stator portion 1, the step of press-fitting the shaft 4 into the rotor housing 6, and the rotor housing 6 and the chuck table portion 5. This is the bonding step. The overall accuracy of the parts involved in the accuracy of the parallelism a and the process involved in the accuracy of the parallelism a affects the parallelism a.

There are three parts involved in the squareness b, and one step involved in the accuracy of the squareness b. The components that are involved in the accuracy of the squareness b are the chassis mounting portion 7, the bearing 9, and the shaft 4 of the stator portion 1. The process related to the accuracy of the squareness b is a press-fitting or caulking process of the chassis mounting portion 7 and the bearing 9 of the stator portion 1. The total accuracy of the squareness b is the total accuracy of the parts involved in the accuracy of the squareness b and the steps involved in the accuracy of the squareness b.

There are seven parts including the rotor housing 6, and the number of steps is from FIG. 10 to FIG.
There are 11 as shown in. For this reason, there is a strong demand for reduction of the number of parts and the number of steps when manufacturing this type of face-to-face type motor.

Therefore, the present invention has been made in order to solve the above problems, and it is possible to reduce the number of parts and the number of steps, which leads to cost reduction.
Moreover, it is an object of the present invention to provide a motor manufacturing method capable of improving reliability.

[0014]

According to the present invention, there is provided a step of outsert-molding a magnet portion and a rotor bearing portion to form a rotor portion in a rotor housing, and a stator bearing portion on a stator substrate. Outsert-molding and arranging a coil to form a stator portion, and arranging a lubricant and a ball between the rotor bearing portion and the stator bearing portion and between the rotor bearing portion and the stator bearing portion. With a gap,
Assembling the rotor portion and the stator portion,
It is achieved by a method of manufacturing a motor including:

In the present invention, preferably, the coil of the stator section is arranged to face the magnet section of the rotor section. In the present invention, preferably, the magnet portion is formed by including magnetic powder in plastic.

In the present invention, preferably, the portions of the first bearing portion and the second bearing portion that receive the sphere are formed in a triangular cross section. In the present invention, preferably the stator substrate is a sheet metal. In the present invention, preferably, in the step of forming the rotor portion, a table portion on which a recording medium is placed is outsert-molded to the rotor housing at the same time as the rotor bearing portion.

[0017]

According to the above construction, the total number of parts, that is, the rotor portion, the stator portion and the sphere can be reduced to three, and the number of steps can be reduced.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings. The examples described below are
Since it is a preferred specific example of the present invention, various technically preferable limitations are attached, but the scope of the present invention is, unless otherwise stated to limit the present invention, in the following description.
It is not limited to these modes.

FIG. 1 shows a preferred embodiment of a motor for explaining the motor manufacturing method of the present invention. First, the structure of this motor will be described with reference to FIG.
This motor includes so-called rotor section 20 and stator section 22.
Are face-to-face motors that face each other. Rotor part 20
Is a rotor housing 30, a chuck table portion 32,
It has a magnet portion 34 and a rotor bearing portion 36.

A magnet portion 34 and a chuck table portion 32 are attached to the rotor housing 30 by adhesion. The rotor bearing portion 36 is provided on the rotor housing 30 by outsert molding. At the center of the rotor bearing portion 36, there is a protrusion 38 for insertion into a hole of a compact disc, for example. The stator portion 22 includes a chassis mounting portion 40 as a stator substrate, a coil 42, and a stator bearing portion 4
4. The coil 42 has necessary circuits and the like, and the coil 42 is arranged around the stator bearing portion 44.

The rotor bearing portion 36 and the stator bearing portion 4
A hard ball 24 and a lubricating oil 26 as a lubricant are arranged between the four. The rotor bearing portion 36 is provided with a hard ball bearing portion having a triangular cross section, for example. Similarly, the stator bearing portion 44 is also formed with a hard ball receiving portion for receiving the hard ball 24. Reference numeral M shown in FIG. 1 denotes a medium mounting surface such as a compact disc, and S denotes a chassis mounting surface of the motor. Θ in FIG. 1 indicates a surface runout angle of the medium mounting surface M with respect to the chassis mounting surface S,
ε indicates a gap formed between the rotor portion 20 also called a rotor assembly and the stator portion 22 also called a stator assembly.

By energizing the coil 42, the rotor portion 20 can rotate in the arrow R direction with respect to the stator portion 22. With such a configuration using the rotor bearing portion 36, the stator bearing portion 44, the hard balls 24, and the lubricating oil 26, the dimension of the motor in the axial direction can be reduced.

Next, a method of manufacturing the rotor portion 20 of this motor will be described with reference to FIGS. 2 to 5, and a method of manufacturing the stator portion 22 will be described with reference to FIGS. 6 to 8.

First, a method of manufacturing the rotor portion 20 will be described in detail with reference to FIGS. As shown in FIG. 2, the rotor housing 30 is formed by, for example, molding a metal plate by sheet metal pressing, and the rotor housing 30 has a hole 30 at the center thereof.
a is formed (step 1).

Next, as shown in FIG. 3, the rotor housing 3
The plastic magnet part 34 is outsert-molded inside 0 (step 2). As the plastic magnet, for example, a mixture of nylon and magnetic powder of iron can be used.

Next, as shown in FIG. 4, a plastic rotor bearing portion 36 and a plastic chuck table portion 32 are simultaneously outsert-molded to the rotor housing 30 (step 3). For the rotor bearing portion 36 and the chuck table portion 32, general plastics other than plastic for outsert molding, such as polyphenylstyrene (PPS), can be used. At this time, the outsert-molded rotor bearing portion 36
The protrusion 38 is formed so as to project into the hole 30 a of the rotor housing 30. In this way, the plastic magnet portion 34 is outsert-molded into the rotor housing 30 to be integrally formed, and then the bearing portion 3
6 and the chuck table portion 32 are integrally molded by plastic outsert molding at the same time, and two-stage molding is performed.

Next, as shown in FIG. 5, the magnet portion 34 of the plastic magnet is magnetized (step 4). Thereby, the rotor portion 20 can be manufactured.

Next, a method of manufacturing the stator portion 22 will be described with reference to FIGS. The chassis mounting portion 40 of the stator portion 22 is formed by sheet metal pressing a metal plate, for example (step 5). A cold rolled steel plate can be used as a material for the sheet metal press. As shown in FIG.
Plastic outsert molding is performed on the chassis mounting portion 40 to form the stator bearing portion 44 (step 6). The stator bearing portion 44 can be fixed by the hole 40a of the chassis mounting portion. As the stator bearing portion 44, for example, a plastic for outsert molding, such as polyphenylstyrene (PPS), or another general plastic can be used.

Next, as shown in FIG. 8, a coil 42 and its circuit (not shown) are provided around the stator bearing portion 44.
Are mounted (step 7). As a result, the stator portion 22 can be completed. As shown in FIG. 5, the rotor bearing portion 36 has a tapered receiving portion 36b for the hard balls 24. Similarly, as shown in FIG. 8, the stator bearing portion 44 has a tapered bearing portion 44b for the hard balls 24.

The rotor portion 20 and the stator portion 22 thus manufactured are assembled as follows. As shown in FIG. 1, the rotor portion 20 is opposed to the stator portion 22 and is assembled through the hard balls 24 and the lubricating oil 26.
At this time, the hard sphere 24 holds the gap ε between the rotor bearing portion 36 and the stator bearing portion 44. By energizing the coil 42, the rotor portion 20 can rotate in the arrow R direction with respect to the stator portion 22.

In the structure of the motor according to the embodiment of the present invention as described above, the angle θ of inclination of the surface of the chuck table 32 is set.
In order to fall within a certain allowable range, it is necessary to maintain the accuracy of the parallelism a and the squareness b at a certain value.

In the embodiment shown in FIG. 1, there are three parts involved in the accuracy of the parallelism a. Further, there are two steps involved in the accuracy of the parallelism a. That is, the three parts that are involved in the accuracy of the parallelism a are the stator part 22, the hard balls 24, and the rotor part 20. The steps involved in the accuracy of the parallelism a include the step of outsert-molding the rotor bearing portion 36 and the chuck table portion 32 into the rotor housing 30 of the rotor portion 20, and the stator portion 22.
It is a total of two steps, that is, the step of outsert-molding and integrally forming the stator bearing portion 44 on the chassis mounting portion 40. The parts involved in the parallelism a and the steps involved in the accuracy of the parallelism a become the overall accuracy of the parallelism a.

Next, the parts involved in the accuracy of the squareness b and the steps involved in the accuracy of the squareness b in the embodiment of FIG.
The steps involved in the accuracy of the parallelism a and the steps involved in the accuracy of the parallelism a are the same. That is, the parts involved in the accuracy of the squareness b and the steps involved in the accuracy of the squareness b are the total accuracy of the squareness b. As described above, the number of parts and the number of steps regarding the parallelism a and the squareness b in the case of manufacturing the motor of the first embodiment can be significantly reduced as compared with the conventional motor.

In the embodiment of FIG. 1, the number of parts is three, that is, the stator portion 22, the rotor portion 20 and the hard balls 24 as described above.
It is a part. Moreover, the number of steps is a total of 7 steps shown in FIGS.

Therefore, the number of parts can be reduced from the conventional 7 parts to 3 parts in the embodiment of the present invention, and the number of parts can be reduced to 43% as compared with the conventional example. Regarding the number of steps, 11 steps were required for the conventional motor, but only 7 steps are required for the motor embodiment of the present invention. Therefore, in the motor of the embodiment of the present invention, the number of steps can be reduced to 64% as compared with the conventional example. For these reasons, a significant cost reduction can be achieved when manufacturing the embodiment of the motor of the present invention.

Further, in the conventional example, the work such as press-fitting, caulking or bonding depends on the accuracy of the jig and the skill of the operator. However, in the motor manufacturing method of the present invention, it is only necessary to outsert-mold the resin on the rotor housing or the resin on the chassis mounting portion using the mold and the resin. In this way, the use of the outsert molding process mainly determines the precision mainly by the mold precision and the characteristics of the plastic material, and it is possible to secure a certain precision level when manufacturing a motor. Therefore, press fitting in the conventional motor manufacturing method,
Higher reliability than caulking or bonding process.

The present invention is not limited to the above embodiment. Although the motor manufactured by the manufacturing method of the present invention is described as rotating an optical recording medium such as a compact disk in the above-mentioned example, the invention is not limited to this, and the information medium such as a floppy disk (FD) may be used. ) Or a magneto-optical recording medium such as a mini disk (MD). Further, the motor manufactured by the manufacturing method of the present invention can be used to mount and rotate an optical element such as a laser polygon mirror, or to drive by winding a magnetic tape or the like.

[0038]

As described above, according to the present invention, it is possible to reduce the number of parts and the number of steps, which leads to cost reduction and reliability improvement.

[Brief description of drawings]

FIG. 1 is a diagram showing a preferred embodiment for explaining a method of manufacturing a motor according to the present invention.

FIG. 2 is a diagram showing a rotor housing of a rotor unit.

FIG. 3 is a view showing a state where a magnet portion is outsert-molded with respect to a rotor housing of a rotor portion.

FIG. 4 is a view showing a state in which a rotor bearing portion and a chuck table portion are outsert-molded with respect to a rotor housing of a rotor portion.

FIG. 5 is a diagram showing a completed rotor portion.

FIG. 6 is a view showing a state where a chassis mounting portion of a stator portion is pressed by sheet metal.

FIG. 7 is a diagram showing a state in which a stator bearing portion is outsert-molded with respect to a chassis mounting portion.

FIG. 8 is a diagram showing a state in which a coil and the like are attached to the chassis attachment portion.

FIG. 9 is a diagram showing an example for explaining a conventional motor manufacturing method.

FIG. 10 is a diagram showing a rotor housing of a rotor portion of a conventional motor.

FIG. 11 is a diagram showing a shaft of a conventional rotor unit.

FIG. 12 is a view showing a magnet portion of a conventional rotor portion.

FIG. 13 is a view showing a chuck table portion for adhering to a rotor portion.

FIG. 14 is a diagram showing a conventional completed rotor portion.

FIG. 15 is a view showing a chassis mounting portion of a conventional stator portion.

FIG. 16 is a diagram showing a state in which a coil is mounted on a conventional chassis mounting portion.

FIG. 17 is a view showing a bearing of a stator part.

FIG. 18 is a diagram showing a completed stator portion.

[Explanation of symbols]

 20 rotor part 22 stator part 24 hard sphere 26 lubricating oil 30 rotor housing 32 chuck table part (table part) 34 magnet part 36 rotor bearing part 40 chassis mounting part (stator part) 42 coil 44 stator bearing part a parallelism b squareness

Claims (6)

[Claims] 1. A step of outsert-molding a magnet portion and a rotor bearing portion into a rotor housing to form a rotor portion; and an outsert-molding of the stator bearing portion onto a stator substrate and arranging a coil to form a stator portion. And assembling the rotor part and the stator part by disposing a lubricant and balls between the rotor bearing part and the stator bearing part and providing a gap between the rotor bearing part and the stator bearing part. And a method of manufacturing a motor. 2. The method of manufacturing a motor according to claim 1, wherein the coil of the stator portion is arranged to face the magnet portion of the rotor portion. 3. The method of manufacturing a motor according to claim 1, wherein the magnet portion is formed by including magnetic powder in plastic. 4. The method for manufacturing a motor according to claim 1, wherein portions of the first bearing portion and the second bearing portion that receive the sphere are formed in a triangular cross section. 5. The motor manufacturing method according to claim 1, wherein the stator substrate is a metal plate. 6. The step of forming the rotor portion comprises:
The method of manufacturing a motor according to claim 1, wherein a table portion on which a recording medium is placed is outsert-molded to the rotor housing at the same time as the rotor bearing portion.