JP2003047196A - Structure of motor for spinner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent whirling vibration or the like by improving the accuracy of moment adjustment with a plurality of kinds of steel balls of different diameters arranged in a self-balancing mechanism. SOLUTION: The structure of a motor for a spinner is configured such that a plurality of annular steps (20, 21 and 22) which differ in diameters each other are formed in an annular groove (10) of the self-balancing mechanism (12), and the steel balls (11a, 11b and 11) are arranged in increasing order of size of the small-diameter steel ball (11a) along the radius direction (B).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor structure for a spinner, and more particularly, to a moment by arranging an annular groove constituting an automatic balancing mechanism as a plurality of annular step portions with different diameters of steel balls. The present invention relates to a new improvement for reducing rotational resonance or whirling vibration by fine adjustment to realize a stable shaft rotation and a silent rotation mechanism.

[0002]

2. Description of the Related Art Conventionally, in a spinner motor structure, generally, in order to change its resonance frequency to a high range, a motor housing is designed to have high rigidity or a motor shaft is designed to be thick. However, in most cases, the wall thickness of the indicating portion is increased in order to increase the rigidity of the bearing portion. That is, as the spinner motor structure having the above-described conventional configuration, the configuration shown in FIGS. 3 and 4 is typical.
The rotating shaft 2 having the rotor 2a is rotatably provided inside the stator 1b of the motor case 1a, and the encoder 3 for detecting the rotation of the rotating shaft 2 is provided.
Is provided at the end of the motor case 1a. A semiconductor wafer 5 is placed on the end of the rotary shaft 2 via a disk 4.

As shown in FIG. 4, a hole 6 for vacuum is formed in the rotary shaft 2, and the semiconductor wafer 5 on the disk 4 is sucked through the hole 6 for vacuum to suck the semiconductor wafer. 5 can be chucked on the disc 4. The above-described configurations shown in FIGS. 3 and 4 have the above-described technical problems, and for example, a semiconductor wafer has a large diameter of 12 inches due to the recent increase in diameter from 8 inches or less. When it comes to semiconductor wafers, this 1
When a 2-inch semiconductor wafer is rotatably supported by a motor having a conventional configuration, the whirling vibration of a spinner motor, which can be ignored in the past, increases with the increase in diameter of the wafer, and cannot be ignored. Further, the whirling vibration causes damage to the wafer. Further, the motor bearing is damaged due to the axial vibration resulting from the whirling vibration. Furthermore, since the whirling vibration frequency is in the audible frequency range, adverse effects such as noise occur. Therefore, in order to solve the above-mentioned problems, an automatic balancing mechanism 12 having a plurality of steel balls 11 operably installed in an annular groove 10 formed in the disk 4 as shown in FIG. 5 is provided. The existing spinner motor structure has been adopted.

Next, the operation principle of the above-mentioned automatic balancing mechanism 12 will be described with reference to FIG. For example, if there is a mass deviation or disc eccentricity due to the label on the surface of the disk placed on the disk of the rotating shaft, there will be a large deflection of the rotating shaft at an arbitrary rotation speed (critical speed), causing a "wirling" phenomenon. To do. An automatic balancing mechanism (ABU) has been proposed to suppress whirling. FIG. 6 shows the qualitative operating principle of the ABU. (A) When stationary, the steel ball is attracted to the inner permanent magnet.
(B) When the centrifugal force (rotation speed) sufficient for the steel ball to leave the permanent magnet is obtained, the steel ball is released to the outside of the groove. Since the phase of the motor portion, the balance mechanism, and the entire eccentric disc is lower than the resonance angular velocity in the rotational region, the steel ball and the structural center of gravity are in the same direction, and the vibration amplitude increases as the rotational speed increases. However, since the phase becomes negative at the angular velocity after resonance (c), the moving direction of the steel ball is opposite to the structural center of gravity. Therefore, the amplitude of the rotary vibration is reduced and the rotary system becomes stable. Recently, an ABU in which a turntable or rotor is provided with an annular groove and a steel ball that can freely move in the groove is inserted
Is being actively researched. The principle is to move the steel ball in the direction to reduce the amount of eccentricity by utilizing the tangential component of the centrifugal force generated in the steel ball.

[0005]

Since the conventional spinner motor structure is constructed as described above, the following problems exist. That is, in the case of the structure using the aforementioned automatic balancing mechanism shown in FIG.
Since a plurality of types of steel balls are arranged in the annular groove, it is impossible to finely adjust the moment less than the moment of one steel ball.

The present invention has been made in order to solve the above-mentioned problems, and in particular, the annular groove forming the self-balancing mechanism is provided as a plurality of annular stepped portions with different diameters of the steel balls. By doing so, it is an object of the present invention to provide a spinner motor structure in which rotational resonance or whirling vibration is reduced by finely adjusting the moment, and a stable shaft rotation and a silent rotation mechanism are realized.

[0007]

A motor structure for a spinner according to the present invention comprises a stator provided in a motor case,
A rotating shaft having a rotor rotatably provided inside the stator; a disk having an annular groove provided at an end of the rotating shaft; and a steel ball operably provided in the annular groove, In a motor structure for a spinner configured to form an automatic balancing mechanism by the annular groove and steel balls, a plurality of steel balls having different diameters are internally provided in the annular groove and the annular grooves have different diameters. A plurality of annular stepped portions are formed, and the steel balls are arranged in the radial direction from the steel balls having a small diameter in order from the small diameter side to the large diameter side of each annular stepped portion. And the angle of the half slope of the wall formed on the annular stepped portion at different radial positions and along a different direction from the radial direction is 88 to 8
The angle is 9 degrees, and the remaining half of the climb is 91 to 92 degrees. Further, among the annular step portions, the wall portion of the annular step portion having the maximum diameter has an angle of 90 degrees for all the climbs. The plurality of steel balls located in the annular stepped portion have the same diameter for each annular stepped portion, and a semiconductor wafer is placed on the disk. This is the configuration.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of a motor structure for a spinner according to the present invention will be described below with reference to the drawings. Incidentally, the motor 1, the encoder 3, the rotary shaft 2 and the disc 4
4 is the same as that of FIG. 4 and only the automatic balancing mechanism 12 provided on the disk 4 is different, and therefore the description thereof is omitted here and the configuration of FIG. 4 is used.

1 and 2 show an automatic balancing mechanism 12 used in the present invention. That is, disk 4
Inside the annular groove 10 formed in a ring shape, for example, first to third annular step portions 20, 21, 22 formed in three steps are provided. The annular step portions 20 to 22 are arranged at different radial positions along the radial direction B when viewed from the vacuum hole 6 located at the axial center A of the disk 4,
The first to third wall portions 30, 31, and 32 are formed in the parts 22 to 22 at different radial positions and in a direction different from the radial direction B.

The angles of the uphill halves 30a and 31a of the first wall portion 30 and the second wall portion 31 are set to 88 to 89 degrees, and the angles of the remaining uphill halves 30b and 31b are 91 to 9.
It is set twice. In addition, the third wall portion 32 of the third annular step portion 22 having the maximum diameter has an angle of 90 degrees for all climbs 32a.
It is composed of degrees.

The radius of each of the annular step portions 20 to 22 is the first
The annular step portion 20 is the smallest, the third annular step portion 22 is the largest, and the second annular step portion 21 is an intermediate shape.
First to third steel balls 11a, 1 operably positioned in 22
The diameters of 1b and 11 are the smallest for the first annular step portion 20, the largest for the third annular step portion 22 and the intermediate diameter for the second annular step portion 21, so that each steel ball 11a, 11b , 11 and the radius of each annular step 20, 21, 22 are arranged in proportion to each other.

Further, the steel balls 11a, 11b, 11 arranged on the annular step portions 20, 21, 22 respectively have the same diameter in each of the annular step portions 20, 21, 22. 1
Only 1b and 11 are arranged, and those having different diameters are not mixed.

Therefore, when the motor 1 is started and the rotary shaft 2 and the disc 4 are rotated in the above-mentioned state, the steel ball having the larger diameter among the steel balls 11a, 11b, 11 in the mixed state in the annular groove 10 It becomes possible for 11 to move over the wall portion 31 to the outermost side by centrifugal force, and the small steel ball 11
The a and 11b are trapped by the respective wall portions 30 and 31 and move in a circular orbital shape so as to minimize the moment, and operate as the automatic balancing mechanism 12. That is, as described above, several types of steel balls 11 having different sizes are used.
Since a, 11b, 11 are arranged on the circular orbits of the annular stepped portions 20, 21, 22 and move on the orbits, the accuracy of moment adjustment of the automatic balancing mechanism 12 is significantly improved as compared with the conventional configuration of FIG. Can be made. The mass of the disk 4 in FIG. 2 functions as an inertial mass, and it is possible to adjust the shaft resonance frequency as a mass for moving the shaft resonance frequency to a frequency outside the range of use of the spinner motor. The multi-stage automatic balancing mechanism 12 has been described in the case of three stages, but it is also possible to have two stages or three or more stages, and to reduce whirling of the spindle motor and all the rotating bodies. It is applicable.

[0014]

The motor structure for the spinner according to the present invention is
Since it is configured as described above, the following effects can be obtained. In other words, since the multi-stage automatic balancing mechanism is provided, it is possible to finely adjust the moment, which was not possible with the conventional one-stage automatic balancing mechanism, and the damage of the semiconductor wafer and the motor shaft support bearing can be prevented. I was able to lose it. Also, compared to the conventional spinner motor, higher performance, higher rotation, and longer motor life have become possible. In addition, the accuracy of the function of the automatic balancing mechanism has been greatly improved compared to the past.

[Brief description of drawings]

FIG. 1 is a sectional perspective view showing an automatic balancing mechanism of a spinner motor structure according to the present invention.

FIG. 2 is a half sectional view of FIG.

FIG. 3 is a perspective view showing a conventional motor structure for a spinner.

FIG. 4 is a partially cutaway perspective view of FIG. 3.

FIG. 5 is a partially cutaway perspective view showing a conventional automatic balancing mechanism.

FIG. 6 is a principle diagram of the operation of FIG.

[Explanation of symbols]

1a motor case 1b stator 2 rotation axes 2a rotor 4 discs B radial direction 5 Semiconductor wafer 10 annular groove 11a, 11b, 11 steel balls 12 Automatic balancing mechanism 20, 21, 22 annular step 30, 31, 32 walls 30a, 31a Half climb 30b, 31b Half of the remaining climb 32a All climbs

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kenji Castle             1879 Okyu, Iida City, Nagano Prefecture Tamagawa Seiki Co., Ltd.             Inside the company F-term (reference) 5F046 JA13                 5H019 AA06 CC03 DD01 FF01                 5H607 AA04 BB01 BB07 BB09 BB14                       CC03 DD02 DD14 EE38

Claims (5)

[Claims] 1. A stator provided in a motor case (1a)
(1b), a rotating shaft (2) rotatably provided inside the stator (1b) and having a rotor (2a), and an annular groove (10) provided at an end of the rotating shaft (2). Disc (4) and the annular groove
A motor structure for a spinner, comprising a steel ball (11) operably provided in (10), and an automatic balancing mechanism (12) comprising the annular groove (10) and the steel ball (11). In, a plurality of steel balls having different diameters in the annular groove (10) (11a,
11b, 11) and a plurality of annular step portions (20, 21, 22) having different diameters are formed in the annular groove (10), and the steel balls (11a, 11b, 11) are radially arranged. (B) along the small diameter steel balls (11a) in order from the annular step (20, 21, 2
A motor structure for a spinner, characterized in that the motor is constructed such that it is arranged from the small diameter side to the large diameter side of 2). 2. The climbing half (30a, 31a) of the wall portion (30, 31) formed in the annular stepped portion (20, 21) at different radial positions and along different directions from the radial direction (B). The angle is 88-8
The spinner motor according to claim 1, wherein the spinner half (30b, 31b) is set at 9 to 92 degrees. 3. The wall portion (32) of the annular step portion (22) having the largest diameter among the annular step portions (20, 21, 22) is provided on all slopes (32).
The motor structure for a spinner according to claim 2, wherein the angle a) is 90 degrees. 4. The plurality of steel balls (11a, 11b, 11) located in the annular step (20, 21, 22) are provided in the annular step (20, 2).
The motor structure for a spinner according to any one of claims 1 to 3, wherein each of the first and 22) has the same diameter. 5. A semiconductor wafer (5) is provided on the disk (4).
2. The structure according to claim 1, characterized in that
The motor structure for a spinner according to any one of 1 to 4.