JP2000339798A - Capstan motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the thickness of a capstan motor. SOLUTION: The capstan motor is provided with a motor base 6, which fixes rotary drive coils 14 and a bearing holder 8 that holds bearings at two locations, a capstan shaft 1, which is rotatively held by the bearings, a rotor 4, which is made integral with the shaft 1, has a rotatively driven magnet 11 and a rotor yoke 10 corresponding to the coils 14 and is made rotative, and a gear 3 provided on the shaft 1. The gear 3 is provided at the upper side of the base 6 of the shaft 1 and is located lower than a tape contacting section 16.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a capstan motor such as a VTR provided with a reel drive transmission gear.

[0002]

2. Description of the Related Art FIG. 3 shows a conventional example of a capstan motor for a VTR movie, and shows a half-section structure diagram (a cross-section is taken on the left side from line AA. ). In the figure, a base 6 and a bearing holder 8 are integrally formed of resin. A magnetic plate 12 constituting a magnetic circuit of the motor is provided below the base 6. The magnetic plate 12 may be an iron plate as long as there is sufficient height, but usually a silicon steel plate is used. Magnetic plate 12
Is mounted with a coil 14 using a rectangular wire. Of course, it may be an ordinary round wire. A bearing 9 for holding the rotation of the capstan shaft 1 is vertically held by the base 6 and the bearing holder 8. A rotor yoke 10 held by a bush 15 is fixed to the lower side of the capstan shaft 1, and a ring-shaped drive magnet 11 is magnetized to 10 poles and rotates corresponding to the coil 14. Rotor yoke 10
A resin FG magnet 12 for generating a rotation control signal is outsert-molded on the outer periphery and multi-pole magnetized to 600 poles (300 pole pairs). A gear 3 for driving a reel (not shown) is press-fitted and adhered and fixed to the lower end of the capstan shaft 1. FIG. 4 shows another conventional example, in which the FG magnet 5 on the outer periphery of the rotor 4 is similar to the case of FIG.
Are provided with 74 tooth-shaped external torque transmission gears 3,
Two oil seals 13 are provided above and below the tape attachment portion 16 of the capstan shaft 1.

[0003]

The above-described conventional capstan motor has a pulley and a gear of a transmission mechanism provided in the direction of the capstan axis of the rotor yoke.
For this reason, there is a problem that the thickness from the motor mounting surface cannot be reduced. Then, this invention aims at providing the capstan motor which solved such a subject.

[0004]

The capstan motor according to the present invention comprises the following means in order to solve the above-mentioned problems. That is,

[0005] A motor base on which a rotary drive coil and a bearing holder holding a bearing at two locations are fixed, a capstan shaft rotatably held by the bearing, and a capstan shaft integrated with the drive coil correspond to the drive coil. A rotatable rotor having a rotary drive magnet and a rotor yoke, and a capstan motor having a gear on the capstan shaft, wherein, above the motor base side of the capstan shaft,
A capstan motor, wherein the gear is provided below a tape attachment portion.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a capstan motor according to the present invention will be described below. FIG. 1 is a schematic configuration diagram showing a determination view of the capstan motor according to the embodiment, in which a flexible printed circuit board 7 is bonded to a metal plate made of silicon steel plate of a base 6, and a coil 14 is further bonded. FIG. 4 is a mounting diagram of a stator, in which a flexible printed circuit board 7 is attached to a motor base 6, and further, electronic components such as a rotary drive coil 14, an MR element 2, and a Hall element 17 are mounted on the flexible printed circuit board 7. This is the completed status 18. The components corresponding to the components in the above-described conventional example are denoted by the same reference numerals for the sake of convenience in order to facilitate comparison.

[0007] In these figures, a bearing holder 8 made of zinc die-casting is attached to a motor base 6. The bearing holder 8 press-fits the ball bearings 9 at two upper and lower portions and holds the capstan shaft 1 for rotation.
The rotor 4 is located below the motor base 6 of the capstan shaft 1.
Is fixed. A drive magnet 11 and a resin FG magnet 5 for a frequency generator (hereinafter, referred to as FG) are formed on the rotor yoke 10 by outsert molding. Stay
The rotor 4 to which the drive magnet 11 magnetized to 10 poles is attached is rotated by the position signal of the rotor 4 generated from the Hall element 17 and the current flowing through the coil 14. Also F
The G magnet 5 has 600 magnetic poles (300 magnetic pole pairs), and a signal detected by the MR element 2 of the magnetic detecting element is output as a rotation speed signal. Capstan axis 1
The external torque transmitting gear 3 is press-fitted and fixed to the base side of the tape attaching portion 16 for magnetic recording / reproducing. On the other hand, an oil seal 13 made of a resin ring is provided above the tape contact portion 16 in order to prevent the oil of the bearing from transmitting and flowing to the tape portion. The lower side is provided with the external torque transmission gear 3 and is not necessary. In the embodiment, the external transmission drive torque is used for driving the VTR reel.

[0000]

According to the capstan motor according to the present invention described in detail above, a thin motor can be constructed since the external drive transmission gear is not provided on the rotor side. Further, the lower oil seal is not required, and the number of parts can be reduced.

[Brief description of the drawings]

FIG. 1 is a half sectional view of a capstan motor according to an embodiment of the present invention.

FIG. 2 is a mounting example of a statuser.

FIG. 3 is a half sectional view of a capstan motor showing a conventional example.

FIG. 4 is a half sectional view of a capstan motor showing another conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Capstan shaft 2 MR element 3 Gear 4 Rotor 5 FG magnet 6 Motor base 7 Flexible printed board 8 Bearing holder 9 Bearing 10 Rotor yoke 11 Drive magnet 12 Magnetic plate 13 Oil seal 14 Coil 15 Bush 16 Tape attaching part

Claims (1)

[Claims] A motor base to which a rotary drive coil, a bearing holder for holding a bearing at two locations are fixed, a capstan shaft rotatably held by the bearing, and a drive shaft integral with the capstan shaft. A capstan motor having a rotatable rotor having a corresponding rotary drive magnet and a rotor yoke, and a gear provided on the capstan shaft, wherein the capstan shaft is above the motor base side and below the tape attachment part. A capstan motor, wherein the gear is provided in the capstan motor.