JP2882058B2 - Tape guide drum device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tape guide drum device used for a magnetic recording / reproducing apparatus for recording / reproducing a signal.

[0002]

2. Description of the Related Art In recent years, as the demand for video tape recorders has increased, higher performance and lower cost have been demanded.

[0003] In addition, a camera-integrated video is required to be smaller and lighter. Therefore, the tape guide drum device is also required to have a larger number of heads, a smaller size, and a lower cost.

An example of a conventional tape guide drum device will be described below with reference to the drawings.

FIG. 3 is a sectional view of a main part of a conventional tape guide drum device. Describing this configuration and operation, first, the sub-rotor 21 is arranged on the lower drum 11,
Next, the stator unit 31 is fixed. Next, a cylindrical holder 22 having a height M is inserted so as to form a predetermined gap L between the rotor magnet 24 and the sub rotor 21.
Then, the yoke 23 to which the rotor magnet 24 is fixed is fixed to the rotor boss 25. The sub rotor 21 is fixed by the magnetic attraction of the rotor magnet 24 and forms a motor unit.

[0006]

However, in the above configuration, the sub-rotor 21 tends to be eccentric with respect to the rotating shaft. Further, when the deflection of the both end surfaces of the holder 22 with respect to the rotation axis is large, or when the warpage of the sub rotor 21 is large, the surface deflection of the sub rotor 21 becomes large, and in the worst case, the sub rotor 21 and the stator holder 32 may come into contact with each other. Therefore, high processing accuracy of the holder 22 is required, and the cost is increased .

[0007]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide a tape guide drum device having high assembling accuracy of a motor section.

[0009]

In order to achieve the above object, the present invention provides a face-to-face stator unit fixed to a lower drum, a rotor magnet opposed to the stator unit and held rotatably, and a rotor. and Saburota substantially disk-like constituting the magnetic circuit of the magnet, the rotor magnetic <br/> Tsu preparative and Saburota also voids scissors stator unit
And the lower drum and / or the connecting member
And the sub rotor is mounted on the lower drum.
Coaxial positioning, where the sub-rotor is arranged coaxially with the rotation axis.
Means .

[0010]

DETAILED DESCRIPTION OF THE INVENTION The present invention therefore improves the assembly accuracy to the configuration described above
it can.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A tape guide drum device according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of a main part of a tape guide drum device according to one embodiment of the present invention, and FIG. 2 is a perspective view of a sub rotor and a holder according to the present invention.

First, the holder 22 outsert-molded on the sub-rotor 21 with a resin material having high molding accuracy is provided on the tapered portion 12 provided on the lower drum 11 and the tapered portion 27 and the sub-rotor 21 are described.
And a height determining portion 28 for keeping the gap L of the rotor magnet 24 constant. The sub-rotor 21 uses a steel plate of a magnetic material, and a gap L2 between the sub-rotor 21 and the stator board 31 and a gap L1 between the sub-rotor 21 and the stator holder 32 so that the stator board 31 and the sub-rotor 21 do not come into contact after the motor assembly process. A stopper 29 is provided at a position where L1 <L2. First, sub rotor 2
1 is inserted into the lower drum 11. At this time, the sub rotor 21 is fixed coaxially with the rotation axis by the tapered portion 12. Next, the stator unit is screwed and fixed to the lower drum 11.
Then, the rotor unit of the rotor magnet 24 and the yoke 23 is fixed to the rotor boss 25, and the motor unit is assembled.

When the rotor unit is inserted,
Are lifted by the magnetic attraction of the rotor magnet 24, but do not contact the stator substrate 31 by the stopper 29. Further, since the sub-rotor 21 is formed integrally with the holder 28 based on the plane portion 40, the runout can be kept very small. Further, the weight is reduced by setting the width S to be the minimum area contributing to the motor characteristics.

As described above, according to the tape guide drum device of the embodiment of the present invention, since the coaxial positioning means of the sub-rotor and the height determining portion between the rotor magnet and the sub-rotor are provided, the assembling work is easy and the assembling is easy. Accuracy can be increased.

[0016]

As is apparent from the above description , the present invention
To obtain a tape guide drum device with improved assembly accuracy
Door can be.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of a tape guide drum device according to an embodiment of the present invention.

FIG. 2 is a perspective view of the sub rotor unit.

FIG. 3 is a sectional view of a main part of a conventional tape guide drum device.

[Explanation of symbols]

 Reference Signs List 11 lower drum 12, 27 taper part 21 sub rotor 22 holder 24 rotor magnet 28 height determining part 29 stopper 31 stator substrate 32 stator holder

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G11B 5/52 101 G11B 15/61

Claims (2)

(57) [Claims] 1. A face-to-face stator unit fixed to a lower drum, a rotor magnet opposed to the stator unit and rotatably held, and a substantially disk-shaped sub rotor constituting a magnetic circuit of the rotor magnet. Before
A connection member in which the rotor magnet and the sub rotor sandwich the stator unit and face each other with a gap;
Along with the lower drum and / or the connection member,
When the sub rotor is mounted on the lower drum,
Coaxial positioning means in which the rotor is arranged coaxially with the rotation axis;
Tape guide drum device having a. 2. A stator unit comprising a stator substrate and a stator holder to which the stator substrate is fixed, wherein the gap between the sub-rotor and the stator holder is at a height such that it is smaller than the gap between the sub-rotor and the stator substrate. 2. The tape guide drum device according to claim 1, further comprising a holder contact member.