JPH0430315A - Rotary head device - Google Patents

Abstract

PURPOSE:To reduce the number of components to facilitate the manufacturing and to regulate the tilt of a rotary drum and a coil with high accuracy by providing a flange to a sleeve member integrally and mounting the rotary drum and the coil to the flange. CONSTITUTION:A rotary drum with magnetic heads 29, 30 fitted thereto and a flange 9b to which a coil being a component of rotary transformers 24, 27 delivering an information signal received and given from/to the magnetic heads is fitted are provided integrally to a sleeve member 9. Thus, the flange is processed based on an axial center of, e.g., the sleeve member 9 to be provided accurately to the axis center of the sleeve member 9 without a tilt. Thus, the flange 9b can supports the rotary drum and the coil accurately without a tilt with respect to the support shaft by allowing the sleeve member 9 to be insert- mounted rotatably for the outside of the support shaft via a liquid bearing.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a rotary head device used in so-called video tape recorders, digital audio recorders, and the like.

B9 Summary of the Invention The present invention provides a rotary head device comprising a fixedly supported support shaft and a sleeve member rotatably fitted onto the support shaft. By attaching the rotating drum with the magnetic head attached to the flange and the coils constituting the rotary transformer, the number of parts can be reduced and manufacturing becomes easier. The inclination of the coil is regulated with high precision.

C1 Prior Art Conventionally, a tape recording medium such as a video tape recorder or a digital audio chip recorder is configured to record and/or reproduce high frequency information signals at high density. In the reproducing apparatus, a rotary head device is used to cause a magnetic head to perform so-called helical scanning on the recording medium.

Such a rotary head device includes a fixed drum fixedly disposed on the chassis of a recording and/or reproducing device configured using this rotary head device. This fixed drum is made of a material such as aluminum and has a substantially cylindrical shape. A support shaft is rotatably mounted on the fixed drum via a bearing along the axis of the fixed drum.

A rotary drum is externally fitted onto one end of the support shaft and is fixed to the support shaft by means such as so-called press fitting. This rotating drum is made of the same material as the fixed drum, and is formed into a cylindrical shape with an outer diameter between the fixed drum and the track.

This rotating drum is attached coaxially to the support shaft.

A plurality of magnetic heads are attached to the side of the rotating drum that faces the fixed drum. These magnetic heads have a distal end side provided with a magnetic gap portion protruding outward from the circumferential surface of the rotating drum by a predetermined amount of approximately 20 μm to 30 μm.

Further, this rotary head device is provided with a rotary transformer for transmitting information signals to and from each of the magnetic heads. This rotary transformer is
It is configured to include a primary coil attached to the rotating head side, and a secondary coil attached to the fixed drum side and facing closely to the secondary coil.

The rotating drum is driven by a motor constituted by a rotor magnet attached to the other end of the spindle and a stator coil attached to the chassis.
It is rotated.

The rotor magnet is formed in an annular shape and is coaxially supported with respect to the rotating drum.

This rotor magnet is magnetized such that a predetermined number of magnetic poles are polarized in the circumferential direction. The stator coil is formed of a plurality of coils into an annular shape with a size equal to the distance between the rotor magnet and the road. This stator coil is opposed to the rotor magnet with a predetermined minute gap therebetween.

In a recording and/or reproducing apparatus using a rotary head device configured as described above, a tape body serving as a recording medium is fed and wound around each of the drums at an angle, and the rotary drum is rotated by the motor. The rotation is operated by. Then, each of the magnetic heads brings the magnetic gap portion into sliding contact with the tape body in a direction inclined to the side edge of the tape body, thereby performing a so-called helical scan.

D0 Problems to be Solved by the Invention However, in the above-described rotary head device, it is difficult to mount the rotary drum accurately with respect to the support shaft without inclination. That is, since the rotary drum is attached to the support shaft by means such as press fitting, there is a possibility that the rotary drum is attached in a state where the axis of the rotary drum and the axis of the support shaft do not coincide with each other.

If the rotating drum is mounted at an angle with respect to the support shaft, the magnetic tape cannot be wrapped around the rotating drum properly.

Furthermore, if the rotating drum is tilted with respect to the spindle, the height position of each magnetic head must be changed. In contrast, it is necessary to increase the distance that can be moved. By increasing the distance that each magnetic head can move relative to the rotating drum, the device configuration can be simplified;
It is difficult to miniaturize the device, and it is also difficult to manufacture it easily.

Furthermore, if the rotating drum is tilted with respect to the support shaft, the coils constituting the rotary transformer will be distorted, making it impossible to properly transmit information signals in the rotary transformer.

Therefore, the present invention is proposed in view of the above-mentioned circumstances, and it is possible to mount the rotary head to which the magnetic head is attached and the coils constituting the rotary transformer accurately with no inclination with respect to the spindle. It is an object of the present invention to provide a rotary head device that can be simplified, and can be simplified in device configuration, downsized, and manufactured easily.

81 Means for Solving the Problems In order to solve the above-mentioned problems and achieve the above-mentioned objects, the rotating head device according to the present invention includes a support shaft that is fixedly supported on the base end side with respect to the chassis via a support member. a sleeve member that is rotatably fitted onto the support shaft via a fluid bearing; and a flange portion that is integrally provided with the sleeve member, and the flange portion has a magnetic head attached thereto. A rotary drum is attached to a coil constituting a rotary transformer that transmits information signals to and from the magnetic head.

F0 Effect In the rotary head device according to the present invention, the flange portion to which the rotary drum to which the magnetic head is attached and the coil constituting the rotary transformer for transmitting information signals to and from the magnetic head is attached to the sleeve. Since it is provided integrally with the member, for example, by machining and providing it using the axis of the sleeve member as a reference, it can be provided in an accurate state with no inclination with respect to the axis of the sleeve member. Therefore, this flange part allows the rotating drum and the coil to be accurately tilted with respect to the support shaft by externally fitting the sleeve member so as to be rotatable with respect to the support shaft via a fluid bearing. can be supported.

G. Examples Specific examples of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, the rotating head device according to the present invention has the following features:
A lower drum 2 and an upper drum 4 are arranged at fixed positions with respect to a chassis 1 of a recording and/or reproducing apparatus configured using this rotary head device, and between these lower drum 2 and upper drum 4, A plurality of rotatably supported magnetic heads 2
9. Middle drum 2 which becomes the rotating drum to which '30 is attached.
8.

In this rotary head device, a magnetic tape serving as a recording medium is wound around each of the drums 2,428, and the middle drum 28 is
is rotated, and the magnetic head 29, 30 is brought into sliding contact with the magnetic tape to write and/or read information signals to and from the magnetic tape.

The lower drum 2 is made of a material such as aluminum and has a substantially round shape. The lower drum 2 is fixedly attached to the chassis 1 by a plurality of lower drum mounting screws 6.6 which are screwed into the lower surface of the chassis 1.

The lower end side of the upper drum support stay 5 is attached to the outer circumferential surface of the lower drum 2 by screws 7 for attaching the stay. The upper drum support stay 5 is formed into a substantially rod shape, and is supported by the lower drum 2 so as to be perpendicular to the chassis l.

The upper drum 4 is attached to the upper end side of the upper drum support stay 5 by screws 8 for attaching the upper drum.

The upper drum 4 is made of a material such as aluminum and is formed into a cylindrical shape having approximately the same diameter as the lower drum 2. This upper drum 4 has its outer peripheral surface attached to the upper drum support stay 5 and is coaxial with the lower drum 2. It is supported by forming a gap corresponding to .

A support shaft 3 is attached to the upper drum 4 along the central axis. That is, the upper drum 4, the upper drum support stay 5, and the lower drum 2,
It constitutes a support member that supports the support shaft 3. This support shaft 3 is press-fitted at its base end side, which is the upper side, into a support shaft insertion hole formed in the upper drum 4 along the central axis of the upper drum 4, and is suspended toward the chassis 1 side. It is supported as such. The lower end of this support shaft 3 is
Projects downward from the chassis 1 through a center hole formed in the lower drum 2 along the axis of the lower drum 2 and a through hole formed in the chassis 1 corresponding to the center hole. has been done.

A sleeve member 9 formed in a cylindrical shape is fitted onto the support shaft 3 so as to be slidable and rotatable. The sleeve member 9 is made of a material such as metal and is slightly longer than the portion of the support shaft 3 that hangs down from the lower surface of the upper drum 4. A liquid having a predetermined viscosity is filled between the inner circumferential surface portion 9a of the sleeve member 9 and the outer circumferential surface portion of the support shaft 3, forming a so-called fluid bearing.

That is, when the sleeve member 9 rotates with respect to the support shaft 3, the liquid forming the fluid bearing circulates between the inner peripheral surface portion 9a and the outer peripheral surface portion of the support shaft 3, thereby generating dynamic pressure. , supports the sleeve member 9 so as to be coaxial with the support shaft 3.

A flange portion 9b is integrally provided on the outer peripheral side of the upper sleeve member 9. This flange portion 9b is provided in an accurately tilted state with respect to the axis of the sleeve member 9. in this way,
In order to provide the flange portion 9b without inclination with respect to the axis of the sleeve member 9, for example, the outer circumferential surface portion, the inner circumferential surface portion 9a, and the flange portion 9b of the sleeve member 9 are cut by so-called simultaneous machining. The sleeve member 9 may be formed by processing.
If the material forming the sleeve member 9 is rotated while still being machined on a lathe, the outer circumferential surface, the inner circumferential surface 9a, and the flange 9b of the sleeve member 9 are sequentially cut using a predetermined cutting tool. good.

The middle drum 28 serving as a rotating drum is attached to the upper surface of the flange portion 9b facing the upper drum 4 so as to be externally fitted onto the sleeve member 9. The middle drum 2 is formed of a material such as aluminum into an annular shape having an outer diameter approximately the same as that of the lower drum 2 and the upper drum 4. This middle drum 2
8 is provided so that the flange portion 9b is not inclined with respect to the sleeve member 9, so that it is accurately supported without being inclined with respect to the axis of the support shaft 3.

A plurality of magnetic heads 29 and 30 are attached to the middle drum 28. These magnetic heads 29 and 30 have their distal ends, where the magnetic gap portion is provided, connected to the middle drum 28.
It is supported so as to protrude outward by a predetermined minute amount of approximately 20 μm to 30 μm from the outer circumferential surface of the support member. Also,
These magnetic heads 29 and 30 are attached to the middle drum 28 so as to be movable and adjustable by minute amounts in the axial direction of the support shaft 3, respectively. These magnetic heads 2
9.30, the axial position of the support shaft 3, so-called mounting height position, is adjusted with an accuracy of within several μm.

Between the lower drum 2 and the flange portion 9b and between the upper drum 4 and the middle drum 28, first and second A second rotary transformer 24.27 is provided. The first rotary transformer 24 is
The primary coil 22 is attached to the flange portion 9b so as to be opposed to the lower drum 2, and the secondary coil 22 is attached to the lower drum 2 with a thickness of, for example, 2o to 30 μm.
and a secondary coil 23 which are attached to face each other with a predetermined gap between them. Further, the second rotary transformer 27 is connected to the middle drum 28.
A primary coil 26 is installed to face the upper drum 4, and a primary coil 26 is installed in the upper drum 4 so as to face the middle drum 28 with a predetermined gap of, for example, about 20 to 30 μm. It consists of an attached primary coil 25. Each of the above-mentioned secondary coils 22°26 is
Since the flange portion 9b and the middle drum 2 are provided or attached to the sleeve member 9 without any inclination, they are accurately supported without inclination with respect to the axis of the support shaft 3. has been done.

The middle drum 28 is located on the lower end side of the sleeve member 9, that is, on the lower side of the chassis 1.
A rotor magnet 12 and a yoke 13, which constitute a motor for rotating the rotor, are attached. That is,
A yoke support member 10 formed in a substantially cylindrical shape is screwed and attached to the outer peripheral side of the lower end of the sleeve member 9.

A magnet support plate 11 and a yoke 13 each having a disk shape are attached to the outer peripheral side of the yoke support member 10. The magnet support plate 11 is made of a so-called high magnetic permeability material, and is attached near the lower end of the yoke support member 10 so as to form a flange. The yoke 13 is formed of the same material as the magnet support plate 11, and is attached to the chassis 1 side with respect to the magnet support plate 11 with a predetermined gap therebetween.

The rotor magnet 12 is formed in an annular shape with an outer diameter approximately equal to the outer diameter of the magnet support plate 11,
It is attached to the side of the magnet support plate 11 facing the yoke 13 so as to be coaxial with the sleeve member 9. This rotor magnet 12 is magnetized so that a predetermined number of magnetic poles are arranged in the circumferential direction. A so-called magnetic gap is formed between the rotor magnet 12 and the yoke 13.

A stator board 15 for supporting the stator coil 14 constituting the motor is attached to the lower surface side of the upper chassis l. This stator board 15 is attached to the chassis 1 via a post 16 to form a predetermined gap, and by screws 17 for mounting the board.

The stator coil 14 is attached to the stator substrate 15 so that it is positioned and supported within the magnetic gap between the rotor magnet 12 and the yoke 13.

In this way, the rotor magnet 12, the yoke 13, and the stator coil 14 constitute the motor. That is, by supplying a predetermined drive current to the stator coil 14, the rotor magnet 12 and the yoke 13 are rotationally driven.

Incidentally, a thrust magnet 18 formed in an annular shape is attached to the side of the yoke 13 facing the lower drum 2. The thrust magnet 18 is inserted into the lower drum 2 through a through hole provided in the chassis 1.
It should be viewed from the bottom of the screen. A disk-shaped thrust lever 19 is attached to the lower surface of the lower drum 2 so as to face the thrust magnet 18 with a predetermined gap of approximately 200 to 500 um. ing. This thrust yoke 19 has a through hole in the center and is configured not to come into contact with the sleeve member 9. This thrust yoke 19 is made of a magnetic material. Therefore, the thrust magnet 1 urges the sleeve member 9 toward the upper drum 4 by attracting the thrust yoke 19.

The suction force generated by this thrust magnet becomes the so-called thrust force in the fluid bearing.

In this rotary head device, the positioning of the sleeve member 9, that is, the positioning of the middle drum 28 and the flange portion 9b with respect to the upper and lower drums 2 and 4, is performed.
This can be done using an adjustment bolt 21 that is screwed into the inner peripheral side of the yoke support member 10 from the lower end side.

The adjustment bolt 21 has a flat upper end facing the flat lower end of the support shaft 3. A spherical member 20 is provided between the adjustment bolt 21 and the support shaft 3.
is interposed. Therefore, the lower ends of the support shafts 3 and the upper ends of the adjustment bolts 21 sandwich the spherical member 20 by the thrust force. That is, the adjustment bolt 2 relative to the yoke support member 10
According to the threading amount of 1, the support shaft 3 of the sleeve member 9
The axial position of this support shaft 3 relative to the shaft 3 is determined.

The sleeve member 9 is fixed by the adjustment bolt 21.
The middle drum 2, the upper drum 4, the flange portion 9b, and the lower drum 2 do not come into contact with each other, and the magnetic heads 29, 30 are installed at substantially predetermined heights, and Each of the above rotary transformers 24.27
The gap between each coil is a predetermined distance.
9 is positioned at a predetermined interval. That is, in this rotating head device, first,
The magnetic heads 29, 30, the primary coils 22, 26 constituting the rotary transformers 24, 27, and the thrust magnet 18 are attached to the sleeve member 9 at predetermined positions. Then, the support shaft 3 of the sleeve member 9 is adjusted such that the height position of each magnetic head 29, 30 is approximately at a predetermined height.
Then, the gap in each of the rotary transformers 24, 27 and the distance between the thrust magnet 18 and the thrust yoke 19 are adjusted more than the height position of each magnetic head 29, 30. The adjustment is completed in this state because the accuracy may be low. Furthermore, fine adjustment of the height position of the magnetic heads 29, 30 is performed by moving and adjusting the magnetic heads 29, 30 relative to the middle drum 28.

In the recording and/or reproducing apparatus configured using the rotary head device according to the present invention configured as described above,
When the recording and/or reproducing mode is set, the magnetic tape is wound around each of the drums 2.4.28 at an angle,
The middle drum 28 is rotated by the motor at a predetermined speed, and the magnetic tape is fed. Then, each of the magnetic heads 29 and 30 comes into sliding contact with the magnetic tape and performs a so-called helical scan.

In this rotating head device, since the rotor magnet 12 and the yoke 13 are rotated at the same speed, there is less magnetic loss between the rotor magnet 12 and the yoke 13, and the drive supplied to the stator coil 14 is reduced. Current can be converted into rotational driving torque with high efficiency. In this rotary head device, the thrust force in the fluid bearing is adjusted by changing the distance between the thrust magnet 18 and the thrust yoke 19, or by changing the magnetic force of the thrust magnet 18. The driving torque of the motor is not changed.

In addition, in this rotary head device, since the motor is provided on the outer side of each of the drums 2, 4.28, the hydrodynamic bearing The span can be increased, and the sleeve member 9 and the middle drum 2 can be supported with high precision without being tilted with respect to the support shaft 3.

H1 Effects of the Invention As described above, in the rotary head device according to the present invention, the rotary drum to which the magnetic head is attached and the coil constituting the rotary transformer that transmits information signals sent to and received from the magnetic head are combined. The attached flange portion is provided integrally with the sleeve member.

For example, the flange portion can be provided by processing the sleeve member based on the fineness of the sleeve member, so that the flange portion can be provided in an accurately tilted state with respect to the axis of the sleeve member.

Therefore, the flange portion allows the rotating drum and the coil to be accurately tilted with respect to the support shaft by externally fitting the sleeve member so as to be rotatable with respect to the support shaft via a fluid bearing. can be supported.

That is, the present invention makes it possible to mount the rotary head to which the magnetic head is attached and the coils constituting the rotary transformer in an accurate state with no inclination with respect to the spindle, thereby simplifying and downsizing the device configuration. Moreover, it is possible to provide a rotary head device that can be manufactured in five steps.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing the configuration of a rotary head device according to the present invention.

Claims (1)

[Scope of Claims] A support shaft whose proximal end side is fixedly supported with respect to the chassis via a support member, and a sleeve member rotatably fitted onto the support shaft via a fluid bearing. and a flange portion provided integrally with the sleeve member, the flange portion forming a rotary drum to which a magnetic head is attached, and a rotary transformer for transmitting information signals to and from the magnetic head. A rotating head device with a coil attached to it.