JPH0573710U - Rotating cylinder device - Google Patents

Abstract

(57) [Summary] [Purpose] The motor can be firmly attached and the thickness can be reduced. A fixed cylinder 1 having a fixed shaft 2, a rotary cylinder 4 having a magnetic head 7 for magnetic recording and reproduction and rotatably provided around the fixed shaft 2, and a motor M for rotationally driving the rotary cylinder 4. And a support member 8 fixed to the fixed shaft 2 is provided on the side of the rotary cylinder 4 opposite to the side facing the fixed cylinder 1, and a flat surface 8a perpendicular to the fixed shaft 2 is formed on the support member 8. At least a part of the stator core 9 of the motor is placed on 8a. [Effect] The stator core can be firmly attached only by mounting and fixing it on the support member, and the axial dimension can be shortened, so that the stator core can be made thin. Also,
The number of screws used can be reduced and the cost can be reduced.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary cylinder device such as a video tape recorder, and more particularly, to a mounting structure for a motor that rotationally drives a rotary cylinder on a fixed shaft.

[0002]

[Prior Art]

 FIG. 2 shows a generally known rotary cylinder device, in which a pair of ball bearings 22 are arranged in a hole in the center axis direction of a fixed cylinder 21, and a rotary shaft 23 is rotatably supported. .. On the lower surface of the fixed cylinder 21, a motor M that urges the rotating shaft 23 to rotate is disposed. The stator core 25 of the motor M is fixed together with a circuit board 26 and a core holder 27, which form a drive circuit, to the lower surface of the fixed cylinder 21 by means of screws 24. A drive magnet 29 provided on the inner peripheral surface of the rotor yoke 28 faces the outer circumference of the stator core 25, and the drive magnet 29 is rotationally biased by the excitation of the stator core 25. Further, a boss 30 is provided at the center of the inside of the rotor yoke 28 and is fixed to the lower end of the rotary shaft 23 so that the rotary shaft 23 is driven to rotate.

A sleeve 31 is attached to the upper end side of the rotary shaft 23 by an appropriate means such as press fitting or bonding, and a rotary cylinder 32 is fixed to a flange 31 a of the sleeve 31 with a screw 33. A head support 34 is attached to the lower surface of the peripheral edge of the rotary cylinder 32 by a screw 35, and a magnetic head 36 is attached to the outer peripheral end of the head support 34. Further, a rotary transformer 37 is arranged between the upper surface side of the fixed cylinder 21 and the sleeve 31.

However, according to the rotary cylinder device described above, the motor M for urging the rotary shaft 23 to rotate is disposed on the lower surface of the fixed cylinder 21, and the rotary cylinder 32 is rotationally driven via the rotary shaft 23. Therefore, there is a problem that the rotation resonance of the rotating shaft 23 causes uneven rotation. Further, if the motor M is arranged below the fixed cylinder 21, the dimension in the axial direction becomes high, and there is a problem that the thickness cannot be reduced.

In order to solve the problems of the conventional rotary cylinder device, a shaft-fixed rotary cylinder device shown in FIG. 3 has been proposed. That is, in FIG. 3, a boss 41 is fixed to the upper end side of a fixed shaft 40 that is planted in a fixed cylinder or the like (not shown) by press fitting or adhesion, and a metal core printed wiring board or the like is attached to the upper end surface of the boss 41. A circuit board 42 consisting of is attached by screws 43. Further, the stator core 45 of the motor M is fixed to the circuit board 42 by screws 46 via a core holder 44. A drive magnet 48 disposed on the inner peripheral surface of the rotor yoke 47 faces the outer circumference of the stator core 45. On the other hand, a rotary cylinder 49 is rotatably provided around the fixed shaft 40 by being supported by a ball bearing 50. A rotor yoke 47 is fixed to the upper surface of the rotary cylinder 49 on the fixed shaft 40 side with screws 51. Then, the drive magnet 48 is rotationally biased by the excitation of the stator core 45, so that the rotary cylinder 49 is rotationally driven.

[0006]

[Problems to be solved by the device]

 However, in the case of the shaft fixed rotary cylinder device described above, the fixed portion of the stator core 45 of the motor M must necessarily be fixed to the center by the screw 46 because of its structure, and the rotor yoke is also fixed. Also in the case of 47, the vicinity of the fixed shaft 40 side must be fixed to the rotary cylinder 49 by a screw 51. For this reason, the heads of the screws 46 and the screws 51 face each other in close proximity, and thus it is necessary to separate them in order to avoid contact between the fixed screw 46 and the rotating screw 51. As a result, there is still a problem that the axial dimension increases and the thickness cannot be reduced. Further, since the stator core 45 of the motor M is fixed to the circuit board 42, there is a problem that the strength is insufficient.

The present invention has been made to solve such a problem, and an object of the present invention is to provide a rotary cylinder device in which a motor can be firmly attached and which can be made thinner. And

[0008]

[Means for Solving the Problems]

 The present invention comprises a fixed cylinder having a fixed shaft, a rotary cylinder having a magnetic head for magnetic recording and reproduction and rotatably provided around the fixed shaft, and a motor for rotationally driving the rotary cylinder. In the rotary cylinder device, a support member fixed to the fixed shaft is provided on the side of the rotary cylinder opposite to the side facing the fixed cylinder, and a flat surface perpendicular to the fixed shaft is formed on the support member. At least a part of the stator core of the motor is mounted on.

[0009]

[Action]

 If a flat surface perpendicular to the fixed shaft is formed on the support member fixed to the fixed shaft on the upper surface side of the rotary cylinder, and at least a part of the stator core of this flat motor is placed, the stator core is only placed and fixed on the support member. Can be attached firmly. Moreover, the screws for mounting on the circuit board are not required, so the axial dimension can be shortened and the thickness can be reduced. In addition, since the number of screws used is reduced, the cost is reduced.

[0010]

【Example】

 An embodiment of the rotary cylinder device according to the present invention will be described below with reference to FIG. In FIG. 1, a fixed shaft 2 is planted in the hole of the fixed cylinder 1 in the direction of the central axis by press fitting or fitting adhesion. An inner ring of a pair of hole bearings 3 is arranged on the fixed shaft 2 above the fixed cylinder 1 with a predetermined distance therebetween. The outer ring of the wheel bearing 3 is fitted in a hole in the direction of the central axis of the rotary cylinder 4, and the rotary cylinder 4 is rotatably provided around the fixed shaft 2. Further, a head support 5 is attached by screws 6 to the lower surface of the peripheral edge of the rotary cylinder 4, and a magnetic head 7 for magnetic recording and reproduction is attached to the outer peripheral end of the head support 5. A rotary transformer 16 is arranged on the center side between the rotating cylinder 4 and the fixed cylinder 1 to exchange signals between the magnetic head 7 and a circuit (not shown).

A supporting member 8 fixed to the fixed shaft 2 is provided above the rotating cylinder 4 on the side opposite to the side facing the fixed cylinder 1 by press fitting or bonding. The supporting member 8 has a small diameter, and a flat surface 8a perpendicular to the fixed shaft 2 is formed on the upper surface. The bottom surface of a recess 9a formed on the lower surface of the central portion of the stator core 9 of the motor M is mounted on the flat surface 8a so as to be joined thereto. A circuit board 11 is superposed above the stator core 9 on the side opposite to the recess 9a via a spacer 10, and is fixed together with the stator core 9 by screws 12 screwed into the upper surface of the support member 8 from above. There is. The circuit board 11 is a metal coplanar wiring board having a magnetic material such as an iron plate as a core, and constitutes a drive circuit and has a magnetic shield function.

A drive magnet 14 provided on the inner peripheral surface of a substantially disc-shaped rotor yoke 13 faces the outer periphery of the stator core 9. The rotor yoke 13 is attached to the upper surface of the rotary cylinder 4 with a screw 15 at the center of the bottom surface and rotates integrally with the rotary cylinder 4. The position of the screw 15 for attaching the rotor yoke 13 is located outside the outer circumference of the support member 8, and as a result, the two are configured to be separated in the axial direction. Then, the drive magnet 9 is rotationally biased by the excitation of the stator core 9, and the rotary cylinder 4 is rotationally driven via the rotor yoke 13.

It should be noted that the present invention is not limited to the above-described embodiments, and the stator core 9 of the motor M, when it is thin, does not need to have the recessed portion 9a, but the lower surface of the central portion is not supported. In other words, the stator core 9 may be mounted on the flat surface 8a of the support member 8 in a manner such that at least a part of the stator core 9 is mounted on the flat surface 8a of the supporting member 8, and various modifications can be made without departing from the scope of the present invention. It is possible.

[0014]

[Effect of the device]

 As is apparent from the above description, in the rotary cylinder device of the present invention, the support member fixed to the fixed shaft is formed with a plane perpendicular to the fixed shaft, and at least a part of the stator core of the motor is placed on this plane. Therefore, the stator core can be firmly attached to the support member. Moreover, since the conventional screw for mounting on the circuit board is not required, the axial dimension can be shortened and the thickness can be reduced. Also, since the number of screws used is reduced, there is an advantage that the cost can be reduced.

[0011]

[Brief description of drawings]

FIG. 1 is a sectional view showing a rotary cylinder device of the present invention.

FIG. 2 is a sectional view showing a conventional rotary cylinder device.

FIG. 3 is a cross-sectional view showing an improved device rotary cylinder device to a fixed shaft type.

[Explanation of symbols]

 1 Fixed Cylinder 2 Fixed Axis 4 Rotating Cylinder 7 Magnetic Head 8 Supporting Member 8a Plane 9 Stator Core 13 Rotor Yoke M Motor

Claims (1)

[Scope of utility model registration request] 1. A fixed cylinder having a fixed shaft, a rotary cylinder having a magnetic head for magnetic recording and reproduction and rotatably provided around the fixed shaft, and a motor for rotationally driving the rotary cylinder. In the rotating cylinder device, a supporting member fixed to the fixed shaft is provided on a side of the rotating cylinder opposite to the side facing the fixed cylinder,
A rotary cylinder device in which a flat surface perpendicular to the fixed shaft is formed on the support member, and at least a part of the stator core of the motor is placed on the flat surface.