JP2910156B2 - Rotating head device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary head device used for a so-called video tape recorder, digital audio tape recorder, or the like.

B. Summary of the Invention The present invention relates to a rotary head device including a support shaft fixedly supported and a sleeve member rotatably fitted around the support shaft, wherein a magnetic head is provided on the sleeve member. By mounting the attached rotary drum, the primary coil constituting the rotary transformer, and the thrust magnet for urging the sleeve member in one direction, the sleeve member is moved and adjusted in the axial direction of the support shaft. Thus, the mounting height position of the magnetic head, the so-called gap amount in the rotary transformer, and the thrust force by the thrust magnet can be adjusted.

C. Conventional technology Conventionally, a tape-shaped recording medium such as a video tape recorder or a digital audio tape recorder is used.
In a recording and / or reproducing apparatus configured to record and / or reproduce a high frequency information signal at a high density,
In order to perform a so-called helical scan on the recording medium by using a magnetic head, a rotary head device is used.

Such a rotary head device is, as shown in FIG.
It has a fixed drum 102 fixedly disposed on a chassis 101 of a recording and / or reproducing apparatus constituted by using this rotary head device. The fixed drum 102 is formed in a substantially cylindrical shape using a material such as aluminum. A support shaft 103 is attached to the fixed drum 102 along the axis of the fixed drum 102 so as to form a pair of ball bearings 104a, 104a.
Via 4b, it is rotatably planted.

Each of the ball bearings 104a and 104b has a plurality of spherical bodies that are rotatably disposed between the outer peripheral surface of the support shaft 103 and the inner peripheral surface of the fixed drum 102. These ball bearings
When the support shaft 103 is rotated with respect to the fixed drum 102, the spherical bodies forming the 104a and 104b roll between the outer circumferential surface of the support shaft 103 and the inner circumferential surface of the fixed drum 102. The support shaft 103 is held at a position coaxial with the fixed drum 102.

On one end of the support shaft 103, a rotating drum support disk 105a is fixedly fitted to the support shaft 103 by means of so-called press-fitting or the like. The rotating drum support disk 105a has a rotating drum 105b.
Are attached to the support shaft 103 so as to be coaxial. The rotating drum 105b is formed of a material similar to that of the fixed drum 102, and is formed in a cylindrical shape having substantially the same outer diameter as the fixed drum 102.

A magnetic head 106 is mounted on a side of the rotating drum 105b facing the fixed drum 102. This magnetic head 106 has a front end side provided with a magnetic gap portion,
On the outer side of the peripheral surface of the rotating drum 105b,
It is projected by a predetermined amount of about 30 μm.

The rotary head device also includes the magnetic head 106
A rotary transformer is provided for transmitting an information signal transmitted to and received from the electronic device. This rotary transformer is configured to have a primary coil attached to the rotary head 105b side, and a secondary coil attached to the fixed drum 102 and closely adjacent to the primary coil. .

The rotating drum 105b is rotated by a motor 109 including a rotor magnet 107 attached to the other end of the support shaft 103 and a stator coil 108 attached to the chassis 101.

The rotor magnet 107 is formed in an annular shape and is coaxially supported by the rotating drum 105. The rotor magnet 107 is magnetized such that a predetermined number of magnetic poles are polarized in the circumferential direction. The stator coil 108 is formed by a plurality of coils into an annular shape having substantially the same size as the rotor magnet 107. The stator coil 108 is opposed to the rotor magnet 107 with a predetermined minute gap. In this way, the rotor magnet 107 and the stator coil 108 are connected to the motor 109 which is a so-called surface-facing motor.
Is composed.

In a recording and / or reproducing apparatus using the rotary head device configured as described above, a tape body serving as a recording medium is fed and tilted and wound around each of the drums 102 and 105b. Is the motor 109
Is rotated. Then, the magnetic head 106
Performs a so-called helical scan by sliding the magnetic gap portion against the tape body in a direction inclined to the side edge of the tape body.

D. Problems to be Solved by the Invention By the way, in the rotating head device as described above,
The positional relationship between the lower drum 102 and the rotary drum 105b is determined by the position of the support shaft 103 with respect to the lower drum 102 and the position of the rotary drum support disk 105a with respect to the support shaft 103. Since the support shaft 103 is supported by the lower drum 102 via the ball bearings 104a and 104b, after the ball bearings 104a and 104b are attached to the lower drum 102, the support shaft 103 is supported by the support shaft 103. Axis 103
Can not move in the axial direction. Further, since the rotating drum support disk 105a is press-fitted and supported on the support shaft 103, after the press-fitting is completed, the support shaft 10
3 can not move in the axial direction.

Therefore, in this rotary head device, the mounting height position of the magnetic head 106 is adjusted by the magnetic head 1.
06 can be performed only by moving the same with respect to the rotating drum 105b. Therefore, it is necessary to mount the magnetic head 106 on the rotating drum 105b such that an adjustment margin for the rotating drum 105b, that is, a movable distance with respect to the rotating drum 105b is increased.

In this rotary head device, the distance between the primary coil and the secondary coil in the rotary transformer, that is, the gap of the rotary transformer is substantially determined by the positional relationship between the fixed drum 102 and the rotary drum 105b. Would. Therefore, in this rotary head device, it is difficult to adjust the gap in the rotary transformer after assembling the fixed drum 102 and the rotary drum 105b.

In this rotary head device, the so-called preload for each of the ball bearings 104a, 104b is obtained by a coil spring that is compressed and fitted between the ball bearings 104a, 104b. Therefore, in this rotary head device, it is difficult to adjust the preload after assembling the rotary head device.

Therefore, the present invention has been proposed in view of the above-described circumstances, and it is possible to adjust the mounting height position of the magnetic head without increasing a movable amount of the magnetic head with respect to a member supporting the magnetic head. And a so-called thrust force adjustment for adjusting the gap of the rotary transformer and positioning the rotary head, which can be easily performed even after assembly.

E. Means for Solving the Problems In order to solve the above problems and achieve the above object, a rotary head device according to the present invention includes a support shaft whose base end in the axial direction is supported on a chassis via a support member. A sleeve member rotatably fitted to the support shaft via a fluid bearing, a rotary drum mounted on the sleeve member and having a magnetic head mounted thereon, and a primary side mounted on the rotary drum. A rotary transformer having a coil and a secondary coil attached to the chassis via a support member, for transmitting an information signal transmitted to and received from the magnetic head, and a rotary transformer for the chassis via the support member A thrust system mounted on the sleeve member for generating a magnetic force to attract the mounted thrust yoke to urge the sleeve member toward the base end of the support shaft in the axial direction. A thrust bearing member for receiving a thrust force caused by an attraction force between the thrust magnet and the thrust yoke; a relative position between the sleeve member and the thrust bearing member is adjusted; By moving the position, the height of the magnetic head, the distance between the magnet, the primary coil, and the secondary coil in the rotary transformer, and the distance between the thrust magnet and the thrust yoke are varied. It is composed.

F. Operation In the rotary head device according to the present invention, when the axial position of the sleeve is rotatably fitted to the support shaft via the fluid bearing, the mounting height of the magnetic head is adjusted. The position, the distance between the primary coil and the secondary coil in the rotary transformer, and the distance between the thrust magnet and the thrust yoke are variable.

G. Examples Hereinafter, specific examples of the present invention will be described with reference to the drawings.

As shown in FIG. 1, a rotary head device according to the present invention has a recording and / or
Alternatively, a lower drum 2 and an upper drum 4 disposed at positions fixed to a chassis 1 of the reproducing apparatus, and a plurality of magnetic heads 29 and 30 rotatably supported between the lower drum 2 and the upper drum 4 are provided. It has a middle drum 28 as a rotating drum to be attached.

In this rotary head device, a magnetic tape as a recording medium is wound around each of the drums 2, 4, and 28, the middle drum 28 is rotated, and the magnetic heads 29 and 30 are brought into sliding contact with the magnetic tape. Is a device for writing and / or reading information signals to and from the magnetic tape.

The lower drum 2 is formed in a substantially cylindrical shape using a material such as aluminum. The lower drum 2 is fixedly mounted on the chassis 1 by a plurality of lower drum mounting screws 6, 6 screwed in from the lower surface side of the chassis 1.

A stay mounting screw 7 is provided on the outer peripheral surface of the lower drum 2.
Thereby, the lower end side of the upper drum support stay 5 is attached. The upper drum support stay 5 is formed in a substantially rod shape, and is supported by the lower drum 2 so as to be perpendicular to the chassis 1.

The upper drum 4 is attached to the upper end side of the upper drum support stay 5 by an upper drum attaching screw 8. The upper drum 4 is made of a material such as aluminum.
The lower drum 2 is formed in a cylindrical shape having substantially the same diameter. The upper drum 4 has an outer peripheral surface portion formed by the upper drum support stay 5.
And is coaxial with the lower drum 2, and is supported by the lower drum 2 by forming a gap corresponding to the thickness of the middle drum 28.

The 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
Constitutes a support member for supporting the support shaft 3. The upper end of the support shaft 3 is press-fitted into a support shaft insertion hole formed in the upper drum 4 along the center axis of the upper drum 4,
It is supported so as to hang down on the chassis 1 side.
The lower end of the support shaft 3 is formed 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. It protrudes below the chassis 1.

The support shaft 3 has a sleeve member 9 formed in a cylindrical shape.
Are externally slidably and rotatably fitted. The sleeve member 9 is formed to be slightly longer than a 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 peripheral surface portion 9a of the sleeve member 9 and the outer peripheral surface portion of the support shaft 3, and a so-called fluid bearing is formed. That is, the shaft 3
On the other hand, when the sleeve member 9 rotates, 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 to generate a dynamic pressure, thereby causing the sleeve member 9 to move. It is supported so as to be coaxial with the support shaft 3.

On the outer peripheral side of the sleeve member 9, the middle drum 28, which is a rotating drum, is fitted and mounted so as to be interposed between the upper drum 4 and the lower drum 2. . The middle drum 28 is formed of a material such as aluminum into a disk shape having substantially the same diameter as the lower drum 2 and the upper drum 4. The center drum 28 has a center hole along the center axis of the center drum 28, into which the sleeve member 9 is fitted.

A plurality of magnetic heads 29, 30 are mounted on the middle drum. These magnetic heads 29 and 30 are supported by projecting a front end side provided with a magnetic gap portion outward by a predetermined minute amount of about 20 μm to 30 μm outside an outer peripheral surface of the middle drum 28. . The magnetic heads 29 and 30 are attached to the middle drum 28 so as to be movable by a small amount in the axial direction of the support shaft 3. In these magnetic heads 29, 30, the position in the axial direction of the support shaft 3, that is, the so-called mounting height position is adjusted with an accuracy of about several μm or less.

A first signal for transmitting and receiving information signals to and from each of the magnetic heads 29 and 30 is provided between the lower drum 2 and the middle drum 28 and between the upper drum 4 and the middle drum 28.
And second rotary transformers 24 and 27 are provided. The first rotary transformer 24 includes a primary coil 23 attached to the lower drum 2 so as to face the middle drum 28, and a primary coil 23 attached to the middle drum 28, for example, 20 to And a secondary coil 22 which is attached so as to be opposed with a predetermined gap of about 30 μm. The second rotary transformer 27
A primary coil 25 mounted in the upper drum 4 so as to face the middle drum 28;
A secondary coil 26 is attached to the primary coil 25 so as to face the primary coil 25 with a predetermined gap of, for example, about 20 to 30 μm.

The middle drum 28 is located at the lower end of the sleeve member 9, that is, at a position below the chassis 1.
A rotor magnet 12 and a yoke 13 constituting a motor for rotating the motor are mounted. That is, a substantially cylindrical yoke support member 10 is screwed and attached to the outer peripheral side of the lower end side of the sleeve member 9. On the outer peripheral side of the yoke support member 10, a magnet support plate 11 and
13 are installed. The magnet support plate 11 is formed of a so-called highly magnetically permeable material, and is attached near the lower end of the yoke support member 10 so as to form a flange. The yoke 13 is connected to the magnet support plate 11
The magnet support plate 11 is formed of the same material as
Is attached to the chassis 1 side from the magnet support plate 11 via a predetermined gap. The rotor magnet 12 is formed in an annular shape whose outer diameter is substantially equal to the outer diameter of the magnet support plate 11, and is coaxial with the sleeve member 9 on the side of the magnet support plate 11 facing the yoke 13. It is attached so that it becomes. The rotor magnet 12 is magnetized such that a predetermined number of magnetic poles are arranged in the circumferential direction. A so-called magnetic gap is provided between the rotor magnet 12 and the yoke 13.

A stator substrate 15 for supporting a stator coil 14 constituting the motor is mounted on the lower surface side of the chassis 1. The stator substrate 15 is attached to the chassis 1 with a predetermined gap formed by interposing a boss 16 with the substrate 1 and a substrate attaching screw 17. The stator coil 14 is mounted on the stator substrate 15 so as to be positioned and supported in a magnetic gap between the rotor magnet 12 and the yoke 13.

Thus, the motor is constituted by the rotor magnet 12, the yoke 13, and the stator coil 14. That is, when a predetermined drive current is supplied to the stator coil 14, the rotor magnet 12
The yoke 13 is driven to rotate.

An annular thrust magnet 18 is attached to the yoke 13 on the side facing the lower drum 2. The thrust magnet 18 is required to face the lower surface of the lower drum 2 through a through hole provided in the chassis 1. The lower drum 2 has a thickness of 200 to 500 μm with respect to the thrust magnet 18.
A disk-shaped thrust yoke 19 is attached so as to be opposed with a predetermined gap therebetween. The thrust yoke 19 has a through hole at the center so that it does not contact the sleeve member 9. The thrust yoke 19 is formed of a magnetic material. Therefore, the thrust magnet 18 urges the sleeve member 9 toward the upper drum 4 by attracting the thrust yoke 19. This thrust magnet
The suction force by 18 becomes a so-called thrust force in the fluid bearing.

The rotary head device is provided with the sleeve member 9.
, That is, the positioning of the middle drum 28 with respect to the upper and lower drums 2 and 4 can be performed using the adjustment bolt 21 screwed into the inner peripheral side of the yoke support member 10 from the lower end side. The adjusting bolt 21 has a flat upper end facing the flat lower end of the support shaft 3. A spherical member 20 is interposed between the adjusting bolt 21 and the support shaft 3. Therefore,
The lower end of the support shaft 3 and the upper end of the adjusting bolt 21 hold the spherical member 20 by the thrust force. That is, the axial position of the support shaft 3 with respect to the support shaft 3 of the sleeve member 9 is determined by the screwing amount of the adjustment bolt 21 into the yoke support member 10.

The sleeve member 9 is moved by the adjusting bolt 21.
The middle drum 28 does not come into contact with either the upper drum 4 or the lower drum 2, and the mounting height position of each of the magnetic heads 29 and 30 becomes substantially a predetermined height. , 27 are positioned at a predetermined distance, and the thrust magnet 18 and the thrust yoke 19 are positioned at a predetermined distance. That is, in this rotary head device, first, the magnetic heads 29, 30; the primary coils 22, 26, which constitute the rotary transformers 24, 27;
Is mounted at a predetermined position with respect to. Then, the position of the sleeve member 9 in the axial direction of the support shaft 3 is adjusted so that the height position of each of the magnetic heads 29 and 30 is substantially a predetermined height. Then, the gaps in the rotary transformers 24 and 27 and the thrust magnet 1
The distance between the thrust yoke 19 and the magnetic heads 8 is
Since the adjustment accuracy may be lower than the mounting height position of 30,
Adjustment is completed in this state. Further, fine adjustment of the mutual mounting height position between the magnetic heads 29, 30 is performed by moving and adjusting the magnetic heads 29, 30 with respect to the middle drum 28.

In the recording and / or reproducing apparatus configured by using the rotary head device according to the present invention configured as described above, when the recording and / or reproducing mode is set, the drums 2, 4, and 28 The magnetic tape is wound obliquely, the middle drum 28 is rotated at a predetermined speed by the motor, and the magnetic tape is fed. Then, the magnetic heads 29 and 30 are brought into sliding contact with the magnetic tape and perform a so-called helical scan.

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

In this rotary head device, since the motor is provided on the outer side of each of the drums 2, 4, and 28, the fluid bearing is smaller than the outer diameter of each of the drums 2, 4, and 28. The span can be lengthened, and the sleeve member 9 and the middle drum 28 can be supported with high precision without causing inclination with respect to the support shaft 3.

Incidentally, in the rotary head device according to the present invention, the shapes and structures of the adjusting bolt 21 and the lower end of the support shaft 3 are the same as those shown in the above-described embodiment, that is, FIG.
As shown in (1), the upper end of the adjusting bolt 21 and the lower end of the support shaft 3 are respectively flattened, and the present invention is not limited to the configuration in which the spherical member 20 is sandwiched therebetween, and can be changed as appropriate.

For example, as shown in FIG. 2A, the adjustment bolt 21 and the support shaft 3 are filled with a liquid having a predetermined viscosity between the adjustment bolt 21 and the lower end portion of the support shaft 3, and a thrust. You may make it comprise a fluid bearing. The adjusting bolt 21 and the lower end of the support shaft 3 do not come into contact with each other because a magnet that generates a magnetic force that separates the adjusting bolt 21 and the lower end of the support shaft 3 is interposed therebetween. You may do so.

Further, the adjusting bolt 21 and the support shaft 3 are connected to each other as shown in FIG.
As shown in the figure, the upper end of the adjusting bolt 21 and the support shaft 3
A conical recess may be provided at each of the lower ends of the spherical members, and the spherical member 20 may be sandwiched between the concave portions.

Further, as shown in FIG. 2C, the adjusting bolt 21 and the support shaft 3 are formed such that the upper end of the adjustment bolt 21 is flat, and a conical recess is provided at the lower end of the support shaft 3.
The spherical member 20 may be sandwiched between them.

As shown in FIG. 2D, the adjustment bolt 21 and the support shaft 3 are formed such that the upper end of the adjustment bolt 21 and the lower end of the support shaft 3 are concave, respectively. The spherical member 20 may be sandwiched. In this example, only one of the upper end of the adjustment bolt 21 and the lower end of the support shaft 3 may have a concave shape. That is, as shown in FIG. 2E, the upper end of the adjusting bolt 21 is flat, the lower end of the support shaft 3 is concave, and the spherical member 20 is sandwiched between them. You may. Further, as shown in FIG. 2F, the upper end of the adjusting bolt 21 is made concave, the lower end of the support shaft 3 is made flat, and the spherical member 20 is sandwiched between them. You may.

In addition, the adjusting bolt 21 and the support shaft 3
As shown in (5), the upper end of the adjusting bolt 21 may be formed in a convex shape, and the lower end of the support shaft 3 may be formed in a flat shape so that they come into contact with each other. Conversely, as shown in FIG. 2H, the adjustment bolt 21 and the support shaft 3
The upper end of the adjusting bolt 21 is flat, and the support shaft 3
May be made convex so that they are in contact with each other.

H. Effect of the Invention As described above, in the rotary head device according to the present invention, the axial position of the support shaft is adjusted by the sleeve member rotatably fitted to the support shaft via the fluid bearing. Then, the mounting height position of the magnetic head, the distance between the primary coil and the secondary coil in the rotary transformer, that is,
The gap in this rotary transformer and the distance between the thrust magnet and the thrust yoke are variable.

Therefore, if the magnetic head, the coil constituting the rotary transformer, and the thrust magnet are mounted at a predetermined position with respect to the sleeve member so that the mutual positional relationship is maintained, the support shaft of the sleeve member is provided. By simply adjusting the position in the axial direction, it is possible to perform positioning at substantially the respective predetermined positions.

That is, the present invention can easily adjust the mounting height position of the magnetic head without increasing the movable amount of the magnetic head with respect to the member supporting the magnetic head, and can adjust the gap of the rotary transformer and the rotary head. It is possible to provide a rotary head device in which the adjustment of the so-called thrust force for positioning of the rotary head can be easily performed even after assembling.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing the configuration of the rotary head device according to the present invention. FIG. 2A is a schematic enlarged side view showing a configuration of the rotary head device using a thrust fluid bearing or a magnetic bearing of the support shaft and the adjustment bolt. FIG. 2B is a schematic enlarged view of the support shaft and the adjustment bolt. FIG. 2C is a schematic partially broken enlarged side view showing a configuration in which a conical recess is provided on both sides, and FIG. 2C is a schematic diagram showing a configuration in which a conical recess is provided on the support shaft and the support shaft of an adjustment bolt. FIG. 2D is a partially broken enlarged side view of FIG.
FIG. 3 is a schematic partially broken enlarged side view showing a configuration in which both ends of the support shaft and the adjustment bolt are concave.
FIG. E is a schematic partially cut-away enlarged side view showing a configuration in which the ends of the support shaft of the support shaft and the adjustment bolt are concave, and FIG. FIG. 2G is a schematic partial cutaway enlarged side view showing a configuration in which the ends of the adjustment bolts are concave, and FIG. 2G shows the support shaft and the ends of the adjustment bolts of the adjustment bolts having a convex shape. FIG. 2H is a schematic enlarged side view showing a configuration, and FIG. 2H is a schematic enlarged side view showing a configuration in which ends of the support shaft and the support shaft of the adjustment bolt are formed in a convex shape. FIG. I is a schematic enlarged side view showing a configuration in which both ends of the support shaft and the adjustment bolt are flattened. FIG. 3 is a longitudinal sectional view showing the configuration of a conventional rotary head device. DESCRIPTION OF SYMBOLS 1 ... Chassis 2 ... Lower drum 3 ... Support shaft 4 ... Upper drum 5 ... Upper drum support member 9 ... Sleeve member 18 ... Thrust magnet 19 ... Thrust yoke 22 ... Primary coil 23 ... Secondary coil 24 ... First rotary transformer 25 ... Secondary coil 26 ... Primary coil 27 ... Second rotary transformer 28 ... Middle drum 29,30 ... Magnetic head

Continuation of the front page (72) Inventor Yoichiro Senshu 6-7-35 Kita-Shinagawa, Shinagawa-ku, Tokyo Inside Sony Corporation (56) References JP-A-63-145821 (JP, A) JP-A-63-122010 (JP, A) JP-A-62-147115 (JP, A) JP-A-61-94215 (JP, A) JP-A-59-71103 (JP, A) JP-A-59-63024 (JP, A) Sho 58-182127 (JP, A) Shokai 59-95428 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) G11B 5/52

Claims (1)

(57) [Claims] 1. A support shaft whose base end in the axial direction is supported on a chassis via a support member, a sleeve member rotatably fitted to the support shaft via a fluid bearing, and the sleeve. A rotary drum mounted on a member and having a magnetic head mounted thereon, a primary coil mounted on the rotary drum, and a secondary coil mounted on the chassis via a support member; A rotary transformer for transmitting an information signal transmitted to and received from the head; and a magnetic force for attracting a thrust yoke attached to the chassis via a support member, thereby causing the sleeve member to move in the axial direction of the support shaft. A thrust magnet attached to the sleeve member biasing to the end side, and a thrust force caused by an attraction force between the thrust magnet and the thrust yoke. A thrust bearing member, wherein a relative position between the sleeve member and the thrust bearing member is adjusted, and a position of the sleeve member in the axial direction of the support shaft is moved, so that a mounting height position of the magnetic head; A rotary head device in which the distance between a magnet, a primary coil, and a secondary coil in a rotary transformer and the distance between the thrust magnet and the thrust yoke are variable.