JPH02223363A - capstan motor - Google Patents

Abstract

PURPOSE:To improve wow and flutter by using a ball bearing with a shaft groove, where a capstan shaft is directly provided with a groove for balls of said ball bearing to roll therein, as a bearing for journaling said capstan shaft. CONSTITUTION:A bearing holder 2 is equipped with a ball bearing 7 with a shaft groove on the output end side and with a ball bearing 8 with an inner ring on the side opposite to the output end side, to journal a capstan shaft 1 by the both bearings 7, 8. Also, a pre-load is applied to the ball bearing 7 with a shaft groove on the output end side in the thrust direction by a pre-load spring 9, and a pre-load is applied to the ball bearing 8 with an inner ring on the side opposite to the output end side in the thrust direction by the attracting force of a driving magnet 5 and a stator yoke 3. That is, factors of the radial run-out of the inner ring and axial runout by a space between the inner ring and capstan shaft 1 are eliminated, because the capstan shaft 1 directly plays the role of the inner ring of the ball bearing 8 with an inner ring in the ball bearing 7 part with a shaft groove. Thus, it is possible to reduce the axial runout and to improve wow and flutter.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application] The present invention relates to a direct section m-type capstan motor used in video table recorders and the like.

[Conventional technology]

6 is a diagram showing a conventional direct drive type capstan motor. In the figure, reference numeral 1 denotes a capstan shaft for driving a tape (not shown), on which an a-ta yoke 6 holding a drive magnet 5 is solidly layered. He received an S rating for Ta. 2 is a bearing holder, and the stator yoke 3 held on the drive coil 4'1 is t! 11 layers, and these valley members 2, 5.4 constitute a stator. The bearing holder 2 is equipped with inner ring ball bearings 8.10 on the output end side and the non-output end side, respectively.
This pivotally supports the capstan @1.

Further, both inner ring ball bearings 8 and 104 are preloaded in the thrust direction by preload springs 9. In addition, as an earlier application regarding this capstan motor, for example, Utility Model Application No. 60-
Publication No. 190175, Japanese Utility Model Application Publication No. 61-17694, etc. are cited.

[Problem to be solved by the invention]

However, in the conventional capstan motor shown in Fig. 6, the capstan shaft 1 and the inner ring ball bearing 8,
100 Due to the gap between the inner ring and the inner ring, or the misalignment between the inner and outer diameters of the inner ring, the capstan shelf 1 may have a large axial tilt (which causes wobble and flutter (the tape speed fluctuation becomes large).
There was an interlude.

The present invention has been made in view of the above points, and its object is to provide a capstan motor with excellent wow and 7 ease.

[Means to solve the problem]

In order to achieve the above object, the present invention includes a rotor equipped with a capstan shaft, an a-ta yoke, and a drive magnet '4r for directly driving the tape, and a rotor that holds the rotor rotatably and in the magnetic field of the drive magnet. In a capstan motor consisting of a stator equipped with a coil that generates a rotating magnetic field that rotates a rotor, at least a part of the bearing for pivotally supporting the capstan shaft 1 is provided with a straight ball shelf support on the capstan shaft. It is configured to use a ball bearing with a shaft groove that prevents the balls from rolling.

[Effect]

In ball bearings with shaft grooves, the capstan shaft directly functions as the inner ring in conventional ball bearings with inner rings, so there is no radial deviation of the inner ring or run-out caused by the gap between the inner ring and the capstan shaft. (As a result, the axial vibration of the Yapstan shaft can be reduced as much as possible, and the wow/black problem can be improved.

〔Example〕

Hereinafter, the present invention will be explained with reference to illustrated embodiments.

FIG. 1 is a sectional view of a capstan motor according to a first embodiment of the present invention. In the figure, reference numeral 1 denotes a capstan shaft for driving a tape (not shown), on which an a-ta yoke 6 holding a drive magnet 5 is solidly layered. It makes up the data. Reference numeral 2 denotes a bearing holder, on which is placed a stator yoke 3 holding a drive coil 4, and these members 2, 5.4 constitute a stator. The bearing holder 2 has a shaft grooved ball bearing 7 on the output end side.
Further, ball bearings 8 with inner rings are provided on the non-output end side, and the capstan shaft 1 is pivotally supported by both bearings 7.8. Further, a preload is applied in the thrust direction by the preload spring 9 to the shaft grooved ball bearing 7 with the output m1lJ, and the reverse output is 12i! A preload is applied to the side inner-ring ball bearing 8 in the thrust direction by the attractive force of the drive magnet 5 and the stator yoke 5.

In this embodiment adopting such a configuration, the shaft grooved ball bearing 7
Since the capstan shaft 1 acts as the inner ring of the ball bearing with a direct inner ring, the radial runout of the inner ring and the cause of shaft runout due to the gap between the inner ring and the capstan shaft are eliminated, making it possible to take pictures of the shaft. It was confirmed that the noise level could be reduced to a level above the previous level, and that wak flutter was significantly improved.

Figure 2 is a sectional view of the lower part of a capstan motor according to a second embodiment of the present invention. A preload is applied by the suction force of the stator yoke 3, and a preload is applied to the ball bearing 8 with an inner ring on the side opposite to the output end by a preload spring 9 that comes into elastic contact with its outer ring and the stepped portion of the bearing holder 2.

Figure S is a sectional view of the main parts of the capstan motor according to the fifth embodiment of the present invention, and in the M5A embodiment, the output ja
A preload is applied to the shaft grooved ball bearing 7 by the attraction force of the drive magnet 5 and the stator yoke 5, and a reverse output of 1? i! A preload is applied to the side ball bearing 8 with an inner ring by a preload spring 9 that comes into elastic contact with a spring bearing 12 fixed to the inner ring and the capstan shaft 1.

FIG. 4 is the 45j! of the present invention! It is a sectional view of a main part of a capstan motor according to an embodiment, and in this embodiment, shaft grooved ball bearings 7 and 11 are arranged on the output end side and the non-output end side, and one double-shaft ball bearing 7 is installed. , 11 has 5iIL on each outer ring!
A preload is applied by a preload spring 9.

Figure 5 is a cross-sectional view of the main parts of a capstan motor according to a fifth embodiment of the present invention. Bearings 11 are respectively arranged, and the ball bearing 10 with an inner ring on the output end side is preloaded by the preload spring 9, and the ball bearing 11 with a shaft groove on the side opposite to the output side is connected to the drive magnet 5. Preload is applied by the suction force of the stator yoke 3.

Even if each of the embodiments of wII2 to FIG. 5 employing the above-mentioned configuration is busy, the same effect as that of the first embodiment is simulated.

〔Effect of the invention〕

As described above, since the present invention uses a ball bearing with a shaft groove, the capstan shaft directly serves as the inner ring of the ball bearing with an inner ring, thereby preventing radial runout of the inner ring.

The cause of shaft runout due to the gap between the inner ring and the capstan shaft is eliminated, the shaft runout can be reduced as much as possible, and wow and flutter can be significantly improved.

[Brief explanation of the drawing]

Figures 1 to 5 relate to embodiments of the present invention, and Figure 1 is a cross section of a capstan motor according to the first embodiment of the present invention.
Figure J2 - Summary 5 causes are part of the genus 2 of the present invention. Fifth, fourth. Sections of main parts showing capstan motors according to the fifth embodiment,
FIG. 6 is a sectional view of a conventional capstan motor. 1...Capstan shaft 2...Bearing holder S・
...Stator yoke 4...Drive coil 5...Drive magnet 6...Rotor yoke 7.11...
@Grooved ball bearing 8, 10...Ball bearing with inner ring 9...Preload spring ¥51 Figure 1-+v1'Swawa wheel 2-・N-holder Holter-5・
-Stator yoke 4-, drive coil 5-, filter L
Dynamic magnet G-Coke yoke 78. Reason grooved I:#
7 History 8-Ball shaft with inner ring 3-Socket pressure lever 2 Fig. 45 Fig. 6 Closed Fig. 4 Helmet 4 Fig. 5 Fig.

Claims (1)

[Claims] 1. A rotor equipped with a capstan shaft, a rotor yoke, and a drive magnet for directly driving the tape, and a rotating magnetic field that rotatably holds the rotor and rotates the rotor in the magnetic field of the drive magnet. In a capstan motor comprising a stator equipped with a coil, at least some bearings for pivotally supporting the capstan shaft,
A capstan motor characterized by using a ball bearing with a shaft groove, which has a groove on the capstan shaft in which the balls of the ball bearing roll directly.