JPH04238107A - Rotary head device - Google Patents

Abstract

PURPOSE:To easily mount a revolving yoke with high accuracy by positioning the revolving yoke with 1st and 2nd positioning surfaces. CONSTITUTION:The 1st positioning surface 137 and the 2nd positioning surface 139 are provided on the revolving yoke 67 of this device. The surface 137 is so provided as to come into contact with the end face of a rotor 79 of a rotary transformer and the 139 to come into contact with the outer peripheral surface of the rotor 79. The positioning in the thrust direction of the yoke 67 is executed by the attraction force of the surface 137 and a rotor 75 of a motor and the positioning in the radial direction of the yoke 67 is executed by the surface 139. An outer ring 65 of a ball bearing 63 which freely rotatably holds a revolving shaft 61 is fixed to a stationary drum 53 by a shrinkage fit and adhesion, by which the shaft 61 is exactly fixed.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] This invention applies to VTR, R-DAT
The present invention relates to a rotary head device used in, for example, a rotary drum, and particularly relates to a rotary head device having a structure in which a rotor of a motor for rotationally driving a rotary drum is built into the rotary drum.

0002

2. Description of the Related Art FIG. 14 is a sectional view of an example of a conventional rotary head device. The rotating head device includes a rotating drum 1, a fixed drum 9, a motor 7, and a rotating shaft 13.

[0003] The rotating shaft 13 is rotatably held by a ball bearing 15. ball bearing 15
The outer ring of is attached to the stationary drum 9 by hot fit and gluing.

[0004] A rotating drum 1 is arranged at a position facing the fixed drum 9. The rotating shaft 13 has a disk 3
is installed. A rotating drum 1 is attached to a disk 3 with attachment screws 2. A magnetic head 11 is attached to the end surface of the rotating drum 1. The magnetic head 11 is rotated to scan a magnetic tape (not shown).

A rotor 5a of a rotary transformer is attached to the disk 3. A stator 5b of a rotary transformer is attached to the fixed drum 9. The rotor 5a of the rotary transformer and the stator 5b of the rotary transformer are opposed to each other. A predetermined air gap is provided between the rotor 5a of the rotary transformer and the stator 5b of the rotary transformer. The rotary transformer sends electrical signals to the magnetic head 11 or receives electrical signals from the magnetic head 11. This rotary transformer is a flat plate type.

[0006] A rotating drum 1 is disposed at one end of the rotating shaft 13. A motor 7 is arranged at the other end of the rotating shaft 13. The motor 7 rotates the rotating shaft 1
3 to rotate. The members that rotate due to the rotation of the rotating shaft 13 are the rotating drum 1, the rotor 5a of the rotary transformer, the disk 3, and the magnetic head 11.

Problems with the rotary head device shown in FIG. 14 will be explained below. With the recent miniaturization of rotating head devices, the rotating shaft 13 tends to become thinner. If the rotating shaft 13 is thin,
When the rotary shaft 13 is rotationally driven by the motor 7, the rotary shaft 1
3 may be twisted. Jitter occurs when the rotating shaft 13 is twisted. Jitter manifests itself in the form of distortion on your TV screen.

[0008] As a solution to this problem, Japanese Patent Laid-Open No.
There is a rotary head device disclosed in Japanese Patent No. -9013. FIG. 15 is a sectional view of a rotary head device disclosed in Japanese Patent Application Laid-Open No. 2-9013. The rotating head device includes a rotating drum 17, a fixed drum 29, and a fixed shaft 31.

The fixed shaft 31 is passed through a ball bearing 41. A disk 43 is attached to the outer ring 27 of the ball bearing 41. As shown in Figure 16,
The fixed shaft 31 is attached to the fixed drum 29 by press-fitting the fixed shaft 31 into a hole 45 provided in the fixed drum 29.

As shown in FIG. 15, the rotating drum 17 is
It is arranged to face the fixed drum 29. The rotating drum 17 is attached to the disk 43 by means of a mounting screw 30.
installed on. The head base 34 is attached to the end surface of the rotating drum 17 with attachment screws 36. A head chip 35 is installed at the tip of the head base 34.
is installed. The head base 34 and head chip 35 constitute a magnetic head.

An earth ring 39 is attached to the fixed shaft 31. The motor stator 25 is attached to the mounting screw 24
It is attached to the ground ring 39 by. Yoke 23 is attached to rotating drum 17 by attachment screws 26. A magnet 21 is attached to the yoke 23. The yoke 23 and the magnet 21 constitute a rotor of the motor. The rotating drum 17 has a rotating yoke 1
9 is installed.

A grounding brush 37 is attached to the yoke 23. The earthing brush 37 is connected to the earthing ring 39
is in contact with. When the rotating drum 17 rotates, the ground brush 37 rotates around the ground ring 39 while contacting the ground ring 39. The rotating drum 17 is grounded by the grounding brush 37.

A stator 33a of a rotary transformer is attached to the fixed drum 29. Rotating drum 17
A rotor 33b of a rotary transformer is attached to the rotor 33b. The stator 33a of the rotary transformer and the rotor 33b of the rotary transformer face each other. A predetermined air gap is provided between the stator 33a of the rotary transformer and the rotor 33b of the rotary transformer.

In the rotary head device shown in FIG. 15, rotating parts include a rotary drum 17, a rotary yoke 19, a magnet 21, a yoke 23, and a rotor 33b of a rotary transformer.
, a head base 34, a head chip 35, a ground brush 37, a ball bearing 41, and a disk 43.

In the rotary head device shown in FIG.
A rotor (yoke 23, magnet 21) of a motor for rotationally driving the rotating drum 17 is attached to the rotating drum 17. Therefore, even if the fixed shaft 31 is thin, no twist occurs in the fixed shaft 31.

[0016]

Problems of the rotary head device shown in FIG. 15 will be described below.

(1) The fixed shaft 31 is attached to the fixed drum 29 by press-fitting technology. For this reason, it has been difficult to accurately provide an air gap between the rotor 33b of the rotary transformer and the stator 33a of the rotary transformer.

Processing of the disk 43 is performed by rotating the disk 43. The fixed shaft 31 is fixed to the fixed drum 2
After the disk 43 is attached to the disk 9, the disk 43 cannot be processed. Therefore, before attaching the fixed shaft 31 to the fixed drum 29, it is necessary to process the disk 43. In this case, for example, when the fixed shaft 31 is tilted, the fixed drum 29
If the rotary drum 17 is installed in a tilted position, the rotating drum 17 can only be installed in an inclined position.

(2) Rotating drum 1 of rotating yoke 19
7 was attached using adhesive or screws. This has been one of the reasons for the increase in the number of manufacturing steps for the rotary head device.

(3) The rotor 33b of the rotary transformer was attached to the rotating drum 17 by adhesive. Therefore, it was impossible to replace the rotor 33b of the rotary transformer.

[0021] The present invention has been made in order to solve the problems of the prior art. SUMMARY OF THE INVENTION An object of the present invention is to provide a rotary head device having a structure in which assembly accuracy can be improved and a rotary yoke can be easily attached.

Still another object of the present invention is to provide a rotary head device having a structure in which assembly accuracy can be improved and the rotor of the rotary transformer can be replaced.

[0023]

A rotary head device according to the present invention scans a magnetic tape by rotating a magnetic head. A rotating head device according to the invention includes a rotating drum, a rotating shaft, a bearing, a fixed drum, a motor stator, and a motor rotor. A magnetic head is attached to the rotating drum. The rotating shaft is attached to the rotating drum. The bearing rotatably holds the rotating shaft. The stationary drum is placed opposite the rotating drum. The fixed drum fixes the outer ring of the bearing. The stator of the motor is attached to a stationary drum. The rotor of the motor is attached to the rotating drum so as to face the stator of the motor.

One aspect of the rotary head device according to the present invention includes a rotor of a coaxial rotary transformer, a stator of a coaxial rotary transformer, a rotating yoke, a first positioning surface, and a second positioning surface. The rotor of a coaxial rotary transformer is attached to a rotating drum. The stator of the coaxial rotary transformer is attached to a fixed drum so as to face the rotor. The coaxial rotary transformer serves to send electrical signals to or receive electrical signals from the magnetic head. The rotating yoke is provided so that the stator is sandwiched between the rotor and the rotating yoke. The first positioning surface is provided on the rotating yoke,
Contact with the end face of the rotor. The second positioning surface is provided on the rotating yoke and contacts the outer peripheral surface of the rotor. Positioning of the rotating yoke in the thrust direction is performed by the first positioning surface and the magnetic attraction force of the rotor. The rotation yoke is positioned in the radial direction by the second positioning surface. Note that, as an example of the first and second positioning surfaces, it is conceivable to provide a step on the rotating yoke.

Another aspect of the rotary head device according to the present invention includes a rotor of a coaxial rotary transformer, a stator of a coaxial rotary transformer, a presser surface, and a presser member. The rotor of a coaxial rotary transformer is attached to a rotating drum.

The stator of the coaxial rotary transformer is
It is attached to a fixed drum so as to face the rotor. The coaxial rotary transformer serves to send electrical signals to or receive electrical signals from the magnetic head. The holding surface is provided on the outer peripheral surface of the rotor of the coaxial rotary transformer. The holding member is removably provided on the rotating drum, and by pressing the holding surface, the rotor of the coaxial rotary transformer is attached to the rotating drum.

[0027]

[Operation] In one aspect of the rotary head device according to the present invention, the rotary shaft is rotatably held by a bearing. The outer ring of the bearing is fixed with a fixed drum. The outer ring of the bearing can be fixed to the stationary drum by means of a hot fit and adhesive. Therefore, the position of the rotation axis can be made accurate. Further, even after the bearing is fixed to the fixed drum, the disk can be rotated by rotating the rotating shaft. Therefore, the disk can be processed even after the bearing is fixed to the stationary drum.

Furthermore, since the rotating yoke is fixed to the rotating drum by the magnetic force of the rotor, the rotating yoke can be easily attached.

Furthermore, the rotor of a rotary transformer is used to position the rotating yoke. Since the rotary transformer is processed by polishing, it can be processed with high precision. Therefore, if the rotor of the rotary transformer is used for positioning, the rotation yoke can be placed accurately.

Another aspect of the rotary head device according to the present invention is that the rotary shaft is rotatably held by a bearing. The outer ring of the bearing is fixed to a fixed drum. The outer ring of the bearing can be fixed to the stationary drum by means of a hot fit and adhesive. Therefore, the position of the rotation axis can be made accurate. Further, even after the bearing is fixed to the fixed drum, the disk can be rotated by rotating the rotating shaft. Therefore, the disk can be processed even after the bearing is fixed to the stationary drum.

Further, the rotor of the rotary transformer is attached to the rotating drum by a holding member. The holding member is removably provided on the rotating drum. Therefore, the rotor of the rotary transformer can be replaced.

[0032]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a sectional view of an embodiment of a rotary head device according to the present invention. The rotating head device includes a rotating drum 51, a fixed drum 53, a ball bearing 63, and a rotating shaft 61.

The ball bearing 63 rotatably holds the rotating shaft 61. The fixed drum 53 fixes an outer ring 65 of a ball bearing 63. The outer ring 65 is fixed to the stationary drum 53 by hot fit and adhesive. Fixed drum 53 is attached to V base 55. The V base 55 is attached to a mechanism chassis 57. A ground brush 59 is attached to the mechanism chassis 57. The ground brush 59 is in contact with the end surface of the rotating shaft 61.

A disk 82 is attached to the rotating shaft 61. A rotating drum 51 is attached to the disk 82. In one embodiment of the rotary head device according to the present invention, the rotary transformer is of a coaxial type. A rotor 79 of the rotary transformer is attached to the rotating drum 51. The stator 81 of the rotary transformer is
It is attached to a fixed drum 53. The rotary transformer sends electrical signals to or receives electrical signals from the magnetic head. A magnetic head 77 is attached to the rotating drum 51.

The rotor 75 of the motor consists of a yoke 73 and a magnet 71. The rotor 75 of the motor is attached to the rotating drum 51 by attachment screws 76 . A rotary yoke 67 is located at the end face of the rotor 79 of the rotary transformer. The rotating yoke 67 is fixed to the rotor 79 of the rotary transformer by the attraction force from the magnet 71.

The motor stator 69 is attached to the fixed drum 53 by mounting screws 70 (the attachment state of the motor stator 69 will be further explained in FIG. 11). It faces the rotor 75.

In FIG. 1, the rotating drum 5
1. Rotating shaft 61, rotating yoke 67, motor rotor 75
, a magnetic head 77, a rotor 79 of a rotary transformer, and a disk 82.

[0038] The outer ring 65 of the ball bearing 63 and the fixed drum 53 are fixed using hot fitting technology and adhesive technology. Therefore, the amount of air gap between the motor rotor 75 and the motor stator 69 can be made more accurate than when they are fixed using a press-fitting technique.

Furthermore, since the disk 82 can be processed even after the ball bearing 63 is fixed to the fixed drum 53, the rotating drum 51 can be mounted with high precision.

Furthermore, since the rotor 75 of the motor for rotationally driving the rotary drum 51 is attached to the rotary drum 51, torsional resonance can be eliminated and rotation precision can be improved.

[0041] Also, since the rotary transformer is a coaxial type,
Compared to the flat plate type, there is no variation in the area facing the core. Since the area facing the core is uniform, the transmission characteristics of the rotary transformer are
All channels will be the same. Since the transmission characteristics of the rotary transformer are the same for all channels, there is no need to adjust the characteristics of the recording/playback amplifier, etc.

Furthermore, since the rotary transformer is a coaxial type, even if the thickness of the rotary transformer is reduced, it will not warp during processing.

Furthermore, the ground brush 59 is in contact with the end surface of the rotating shaft 61. Therefore, the rotation precision of the rotary drum 51 can be improved compared to the rotary head device shown in FIG. 15.

FIG. 2 is a sectional view of a magnetic head provided in an embodiment of a rotary head device according to the present invention. The magnetic head 77 includes a head base 91 and a head chip 83.
It is equipped with The head base 91 has mounting screws 93
It is attached to the rotating drum 51 by. The end surface of the rotating drum 51 and the back surface 88 of the head base 91 are in contact with each other. A head chip 83 and a terminal plate 89 are attached to the surface 86 of the head base 91.

A coil 101 is wound around the head chip 83. Coil 101 is fixed by molding material 85. Coil 101 is electrically connected to terminal plate 89. Terminal board 89 is electrically connected to a rotary transformer (not shown). The height of the head chip 83 is adjusted by bending the head base 91 using the height adjustment screw 95.

The distance L1 from the tip of the head chip 83 to the end of the head base 91 is the following: when the head chip 83 is attached to the front surface 86 of the head base 91, and when the head chip 83 is attached to the back surface 88 of the head base 91. It can be made shorter than .

FIG. 3 is a plan view of a magnetic head included in an embodiment of the rotary head device according to the present invention. As shown in FIG. 3, the head base 91 is provided with a mounting hole 97 and a notch 99. The head base 91 is fixed to the rotating drum 51 by passing the mounting screws 93 shown in FIG. 2 through the mounting holes 97. head base 91
A head chip 83 is attached to the head. A coil 101 is wound around the head chip 83.

Terminal plate 10 is attached to head base 91 shown in FIG.
5 is shown in Figure 4. The coil 101 is electrically connected to a first connection portion 107 on the terminal plate 105. The second connection part 109 of the terminal board 105 is a lead pin (not shown) that is electrically connected to the rotary transformer.
electrically connected to.

As explained earlier, the head chip 83
The height is determined by bending the head base 91. By the way, the equation for the deflection of the beam is expressed as follows.

d2 y/dx2 =M/EI=12Pl/Ebh3
M... Bending moment E... Modulus of longitudinal elasticity I... Quadratic moment of area P... Force applied from the height adjustment screw l... Distance from the fixed part of the head base 91 to the point of action of P (1 is written in lower case in the drawing) b... Width of the head base 91 h... Thickness of the head base 91 Bending stress is expressed as σ=6Pl/bh2, and the allowable stress is determined depending on the material. P for giving a predetermined displacement is determined from the displacement equation, but at the same time it is also necessary that the bending stress does not exceed the allowable stress (because we want to use it within a range where it has springiness). Therefore, it is preferable that the value of P be as small as possible. Methods of decreasing the value of P and obtaining the desired deflection include increasing the value of l, decreasing the value of b, and decreasing the value of h.

However, increasing the value of l increases the value of L1 shown in FIG. 2, which is not preferable. The value of h is 0.8 from the viewpoint of the strength and manufacturability of the head base 91.
The limit is about mm. Therefore, in this invention, the value of b is made small. The head base 91 has a terminal board 1
05, it is not possible to reduce the entire width of the head base 91. Therefore, in the present invention, by providing the notch 99, the terminal plate 10
5 and the need to reduce the width b are satisfied. Note that a through hole may be provided instead of the notch.

FIG. 5 is a sectional view of a motor included in an embodiment of the rotary head device according to the present invention. FIG. 6 is a plan view of the motor shown in FIG. 5. FIG. 7 is a plan view of the stator 69 of the motor shown in FIG. FIG. 8 shows the shield ring 11 that supports the stator 69 of the motor shown in FIG.
1 is a plan view of FIG. FIG. 9 is a cross-sectional view of the shield ring 111 shown in FIG. 8 taken from the direction of arrow A.

As shown in FIG. 5, the motor rotor 75 has a yoke 73 and a magnet 71 attached thereto. By fixing the mounting boss 113 provided on the yoke 73 and the rotating drum 51 shown in FIG. 1 with the mounting screws 76,
A motor rotor 75 is attached to the rotating drum 51.

As shown in FIG. 5, the motor stator 69 is attached to a shield ring 111. As shown in FIG. The shield ring 111 functions to maintain the flatness of the stator 69 of the motor.

As shown in FIGS. 5 and 7, a protrusion 121 is provided on the stator 69 of the motor. As shown in FIG. 7, the protrusion 121 is provided with a connection hole 123. The stator 69 of the motor has a ring shape. The stator 69 of the motor includes a plurality of drive coils 119.
is provided. Electrical connection between the drive coil 119 and the connection pin 117 (see FIG. 5) provided on the lead wiring member 115 is made by the protrusion 121.

When the connection hole 123 shown in FIG. 7 is provided in the drive coil 119 forming portion of the stator 69 of the motor, the drive coil 119 located at that portion becomes smaller than the drive coil 119 located at other portions. Therefore, the magnetic flux generated from the drive coil 119 at the connection hole is smaller than the magnetic flux generated from the drive coil 119 at other parts.

By the way, the magnetomotive force is F=B・I・l (B:
Magnetic flux density, I: current, l: effective length of the coil). The drive coil 119 located at the connection hole has a smaller coil area than the others, that is, the effective length of the coil is shorter, and the magnetomotive force is smaller. On the other hand, in order to make the magnetomotive force the same, it is necessary to increase the current from the above (compared to an example of coil dimensions that are all the same). As a result, power consumption increases. In the present invention, such a problem does not occur because the drive coils 119 are all the same size.

As shown in FIG. 8, the shield ring 111
is provided with a stator fixing portion 131. A rising portion 127 is provided around the stator fixing portion 131. A raised portion 127 is not provided in a portion corresponding to the protruding portion 121 shown in FIG. A fixing screw hole 125 is provided in the shield ring 111. The shield ring 111 is fixed to the fixed drum 53 by attaching the mounting screws 70 shown in FIG. 1 to the fixing screw holes 125. The shield ring 111 is made of a magnetic material such as permalloy.

FIG. 10 shows the stator 69 of the motor shown in FIG.
FIG. 3 is a perspective view for explaining the attached state. A step is provided on the outer periphery of the fixed drum 53, and this step serves as a lead portion 135. The lead portion 135 regulates the running of the magnetic tape. In one embodiment of the rotary head device according to the present invention, a notch 133 is provided in a portion of the outer peripheral surface of the fixed drum 53 where the magnetic tape is not wound.
A lead wiring member 115 having a connecting pin 117 attached thereto is fitted into the notch 133 .

FIG. 11 is an enlarged cross-sectional view of a motor included in an embodiment of the rotary head device according to the present invention. The ball bearing 63 rotatably holds the rotating shaft 61. An outer ring 65 of a ball bearing 63 is fixed by a fixed drum 53. Shield ring 111 is attached to stationary drum 53 by attachment screws 70. The shield ring 111 supports the stator 69 of the motor. Between the stator 69 of the motor and the fixed drum 53, there is a raised portion 1 provided on the shield ring 111.
There are 27.

A disk 82 is attached to the rotating shaft 61. A rotating drum 51 is attached to the disk 82. A rotor 79 of a rotary transformer is attached to the rotating drum 51. The fixed drum 53 has
A stator 81 of a rotary transformer is attached.

The rotor 75 of the motor consists of a yoke 73 and a magnet 71 attached thereto. By fitting the mounting screw 76 into the mounting boss 113 provided on the yoke 73,
The rotor 75 of the motor is attached to the rotating drum 51.

The rotary yoke 67 has a first positioning surface 13
7 and a second positioning surface 139 are provided. The rotation yoke 67 is positioned in the thrust direction by the first positioning surface 137 and the attractive force of the magnet 71. The rotation yoke 67 is positioned in the radial direction by a second positioning surface 139.

As rotary head devices become smaller, the thickness of the outer peripheral portion of the fixed drum 53 tends to become thinner. Currently, some fixed drums 53 have an outer peripheral wall thickness of approximately 0.6 mm. On the other hand, in order to increase the rotational speed of the motor with less electric power, it is desirable to provide the motor at a position as far away from the rotating shaft 61 as possible. If the motor is located away from the rotating shaft 61, the distance between the magnetic tape and the motor will be shortened, and the magnetic tape will be affected by the magnetic force of the motor. In one embodiment of the rotary head device according to the invention, there is a raised portion 127 made of a magnetic member between the stator 69 of the motor and the outer periphery of the fixed drum 53. Therefore, it is possible to prevent the magnetic tape from being influenced by the magnetic force of the stator 69 of the motor. The thickness of the rising portion 127 is 0.
．． If the thickness is 1 mm or more, a magnetic shielding effect can be expected. If the rising portion 127 is extended further upward, the magnetic force of the rotor 75 of the motor can be shielded.

As shown in FIG. 11, in one embodiment of the rotary head device according to the present invention, the rotary yoke 67 is positioned using the attractive force from the rotor 79 of the rotary transformer and the magnet 71. There is. Since rotary transformers are processed by grinding, they can be processed with high precision. Since the rotor 79 of the rotary transformer is used as a reference for positioning the rotating yoke 67, the rotating yoke 67 can be positioned accurately. Furthermore, since the rotating yoke 67 is attached using the attraction force from the magnet 71, the rotating yoke 67 can be easily attached to the rotor 79 of the rotary transformer.

FIG. 12 is a cross-sectional view for explaining how the rotor of a rotary transformer is installed in an embodiment of the rotary head device according to the present invention. Figure 13 shows
FIG. 2 is a plan view illustrating a state in which a rotor of a rotary transformer provided in an embodiment of a rotary head device according to the present invention is attached. As shown in FIG. 12, the rotating drum 5
The rotor 79 of the rotary transformer is positioned in the thrust direction by a reference surface 143 provided at the rotary transformer 1. A step is provided on the outer periphery of the rotor 79 of the rotary transformer. A buffer member 145 is fixed to the outer periphery of the rotor 79 of the rotary transformer with an adhesive. The buffer member 145 is positioned by a step provided on the outer peripheral surface of the rotor 79 of the rotary transformer.

The rotor 79 of the rotary transformer is attached to the rotating drum 51 by pressing the buffer member 145 with the leaf spring 147. The leaf spring 147 is attached to the mounting screw 1
49, it is attached to the rotating drum 51.

A lead pin 151 is attached to the buffer member 145. A connection portion 153 between one end of the lead pin 151 and the wiring of the rotor 79 of the rotary transformer is located in a through hole 157 provided in the rotating drum 51. The other end of the lead pin 151 is electrically connected to the terminal plate 89.

As shown in FIG. 13, the buffer member 145 is provided with a recess 155. Place the leaf spring 147 in the recess 1
55, the leaf spring 147 is attached to the mounting screw 1.
49 prevents the leaf spring 147 from rotating during installation.

As shown in FIGS. 12 and 13, in one embodiment of the rotary head device according to the present invention, the rotor 79 of the rotary transformer is attached to the rotating drum 51 using a leaf spring 147. Therefore, the rotor 79 of the rotary transformer can be replaced. The reason why the buffer member 145 is provided between the leaf spring 147 and the rotor 79 of the rotary transformer is as follows. The rotor 79 of the rotary transformer is made of ferrite, which is a brittle material. Therefore, if the rotor 79 of the rotary transformer is directly pressed by the leaf spring 147, the rotor 79 of the rotary transformer may be damaged. As the material of the buffer member 145, a soft member such as resin is preferable.

Further, as shown in FIG. 12, in one embodiment of the rotary head device according to the present invention, a connection between one end of the lead pin 151 and the rotor 79 of the rotary transformer is provided on the rotary drum 51. Since soldering is carried out in the through-hole 157 which is formed in the same manner as shown in FIG. The other end of the lead pin 151 is attached to the terminal plate 8 when the rotor 79 of the rotary transformer is attached to the rotating drum 51.
It is made to come in contact with 9. Note that if the rotor 79 of the rotary transformer is not damaged even if the rotor 79 of the rotary transformer is directly pressed by the leaf spring 147, the buffer member 145 may not be provided.

[0072]

[Effect] One aspect of the rotary head device according to the present invention is that the position of the rotary shaft can be made accurate. Therefore, it is possible to accurately provide an air gap between the rotor of the rotary transformer and the stator of the rotary transformer. Further, since the disk can be processed even after the bearing is fixed to the fixed drum, the rotating drum can be accurately positioned.

Furthermore, since the rotating yoke is fixed to the rotating drum by the magnetic force of the rotor, the rotating yoke can be easily attached. Therefore, the manufacturing process of the rotary head device can be simplified.

Furthermore, since the rotor of the rotary transformer is used for positioning the rotating yoke, the rotating yoke can be positioned accurately.

Another aspect of the rotary head device according to the present invention is that the position of the rotary shaft can be made accurate. Therefore, it is possible to accurately provide an air gap between the rotor of the rotary transformer and the stator of the rotary transformer. Further, since the disk can be processed even after the bearing is fixed to the fixed drum, the rotating drum can be accurately positioned.

Furthermore, since the rotor of the rotary transformer can be replaced, it is advantageous in terms of maintenance of the rotary head device.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an embodiment of a rotary head device according to the invention.

FIG. 2 is a sectional view of a magnetic head included in an embodiment of a rotary head device according to the present invention.

FIG. 3 is a plan view of a magnetic head included in an embodiment of a rotary head device according to the present invention.

4 is a plan view of the magnetic head shown in FIG. 3 with a terminal plate attached thereto; FIG.

FIG. 5 is a sectional view of a motor included in an embodiment of the rotary head device according to the present invention.

FIG. 6 is a plan view of the motor shown in FIG. 5;

7 is a plan view of the stator of the motor shown in FIG. 5. FIG.

8 is a plan view of a shield ring that supports the stator of the motor shown in FIG. 5. FIG.

9 is a cross-sectional view of the shield ring shown in FIG. 8 taken from the direction of arrow A. FIG.

10 is a perspective view for explaining how the stator of the motor shown in FIG. 7 is attached; FIG.

FIG. 11 is an enlarged sectional view of a motor included in an embodiment of a rotary head device according to the present invention.

FIG. 12 is a sectional view illustrating a state in which a rotor of a rotary transformer provided in an embodiment of a rotary head device according to the present invention is attached.

FIG. 13 is a plan view illustrating a state in which a rotor of a rotary transformer provided in an embodiment of the rotary head device according to the present invention is attached.

FIG. 14 is a sectional view of an example of a conventional rotary head device.

FIG. 15 is a sectional view of a rotary head device disclosed in Japanese Patent Application Laid-Open No. 2-9013.

FIG. 16 is a sectional view for explaining how the fixed shaft shown in FIG. 15 is fixed to the fixed drum.

[Explanation of symbols]

51 Rotating drum 53 Fixed drum 59 Earth brush 61 Rotating shaft 63 Ball bearing 65 Outer ring 67 Rotating yoke 69 Motor stator 75 Motor rotor 77 Magnetic head 79 Rotary transformer rotor 81 Rotary transformer stator 137 First
Positioning surface 139 Second positioning surface 145 Buffer member 147 Leaf spring

Claims (3)

[Claims] 1. A rotary head device that scans a magnetic tape by rotating a magnetic head, comprising: a rotary drum to which the magnetic head is attached; a rotary shaft attached to the rotary drum; and a rotary shaft to which the magnetic head is attached. a fixed drum that is arranged opposite to the rotating drum and fixes an outer ring of the bearing; and a stator of a motor that is attached to the fixed drum and that rotationally drives the rotating drum. , a rotor of the motor attached to the rotating drum so as to face the stator; a rotor of a coaxial rotary transformer attached to the rotating drum;
a stator of the coaxial rotary transformer attached to the fixed drum so as to face the rotor;
The coaxial rotary transformer has a function of transmitting an electric signal to the magnetic head or receiving an electric signal from the magnetic head, and further includes a rotating coaxial type rotary transformer that is provided to sandwich the stator between the rotor and the rotor. a yoke; a first yoke provided on the rotary yoke and in contact with an end surface of the rotor;
a positioning surface; and a second positioning surface provided on the rotary yoke and in contact with the outer circumferential surface of the rotor; A rotary head device, wherein the positioning of the rotary yoke in the radial direction is performed by the second positioning surface using suction force. 2. The rotating yoke is provided with a step,
the step is the first and second positioning surfaces;
The rotary head device according to claim 1. 3. A rotary head device for manipulating a magnetic tape by rotating a magnetic head, comprising: a rotary drum to which the magnetic head is attached; a rotary shaft attached to the rotary drum; a bearing that is rotatably held; a stationary drum that is disposed opposite to the rotating drum and that fixes an outer edge of the bearing; and a stator of a motor that is attached to the stationary drum and that rotationally drives the rotating drum; a rotor of the motor attached to the rotating drum so as to face the stator; a rotor of a coaxial rotary transformer attached to the rotating drum; and a rotor of the motor attached to the rotating drum so as to face the stator; a stator of the coaxial rotary transformer attached to a drum, the coaxial rotary transformer having a role of transmitting an electric signal to the magnetic head or receiving an electric signal from the magnetic head, and further comprising: a pressing surface provided on the outer peripheral surface of the rotor of the coaxial rotary transformer;
A rotary head device comprising: a presser member that is removably provided on the rotary drum and that attaches a rotor of the coaxial rotary transformer to the rotary drum by pressing the presser surface.