JPH02214005A - Rotating magnetic head drum device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention is used in a magnetic recording and reproducing device that records on and reproduces magnetic tape using a helical scan method, such as a video tape recorder, and is particularly suitable for recording and reproducing video signals with a large number of channels. The present invention relates to a rotating magnetic head drum device that is effective for transmitting and receiving information.

[Conventional technology]

In magnetic recording and reproducing devices such as video tape recorders,
In order to add various functions such as a special reproduction function and an editing function, it is necessary to add magnetic heads and increase the number of channels according to the functions. Furthermore, as the number of magnetic heads increases, the number of windings of the rotary transformer must be increased, and the area in which the stator-side core and the rotor-side core of the rotary transformer face each other must be increased.

Therefore, the applicant of the present application proposed a structure in which the area where the stator side core and the rotor side core face each other is increased without increasing the size of the rotating magnetic head drum device in the invention filed in Utility Model Application No. 63-48037. is suggesting.

As shown in FIG. 7, such a rotating magnetic drum device includes an upper bearing 2 at the upper part of the central cylindrical part la of the lower drum 1 in a fixed state, and a lower bearing 2' at the lower part. is provided. A shaft 3 serving as a rotating shaft is inserted into the central cylindrical portion 1a, and is fitted into the upper bearing 2 and the lower bearing 2' to be rotatably supported. A motor rotor 4 is fixed to the lower end of this shaft 3, while a disk 5 is fixed to the vicinity of the upper end of the shaft 3, and an upper drum 7 to which a magnetic head 6 is attached is fixed to the outer periphery of this disk 5. has been done.

On the lower end surface of the disk 5 that rotates together with the shaft 3,
A flat rotor-side core 8 is attached. on the other hand,
At the bottom of the recess of the lower drum 1 is a flat stator side core 9.
is attached so as to face the rotor-side core 8. The rotor-side core 8 and the stator-side core 9 constitute a rotary transformer 10, and the amount of clearance between the rotor-side core 8 and the stator-side core 9 is strictly controlled with high precision.

Also, the upper bearing 2 and lower bearing 2' of the shaft 3
A cylindrical rotor-side core 11 is provided on the outer peripheral surface between the
is installed. On the other hand, a cylindrical stator-side core 12 is attached to the inner peripheral surface of the central cylindrical portion 1a of the lower drum l so as to face the rotor-side core 11. The rotor side core 11 and the stator side core 12 constitute a rotary transformer 13, and the rotor side core 1
Similarly to the rotary transformer 10, the amount of gap between the rotary transformer 1 and the stator-side core 12 is strictly controlled with high precision.

In the rotary transformer IO, the rotation of the upper drum 7 causes the rotor side core 8 and the stator side core 9 to
The reproduction signal from the magnetic head 6 and the recording signal to the magnetic head 6 are transmitted between the magnetic head and the magnetic head. Further, in the rotary transformer 13, similarly to the rotary transformer lo, the reproduction signal and the recording signal are transmitted between the rotor-side core 11 and the stator-side core 12 by the rotation of the upper drum 7.

Incidentally, in the above-mentioned rotating magnetic head drum device, there are no regulations regarding the wiring process from the stator side core 12 of the rotating transformer 13 to the outside. Therefore, as a rotating magnetic head drum device that takes the above-mentioned wiring processing into consideration, the following configuration can be considered. The rotating magnetic head drum device shown in FIG. 8 has the same main parts as the rotating magnetic head drum device shown in FIG. 7, so the same reference numerals will be used for explanation.

As shown in FIG. 8, a cylindrical rotor-side core 11 is attached to the shaft 3 between the upper bearing 2 and the lower bearing 2' in the central cylindrical portion 1a, while the inner circumferential surface of the central cylindrical portion 1a A cylindrical stator-side core 12 is attached to the rotary transformer 13.

In the vicinity of the lower end surface of the drum portion 1b in the central cylindrical portion 1a, there are four communicating holes 1c penetrating from the inner circumferential surface to the outer circumferential surface.
is provided. The signal lines 14 of the stator-side core 12, which are divided into four groups in advance, are pushed through the communication holes 1c and connected to the relay boards 15 provided on the lower end surface of the drum part 1b. Connected, relay board 15...
- is further connected to an external circuit (not shown) to exchange signals.

Here, the assembly of the stator side core 12 to the central cylindrical portion 1a will be explained.

As shown in FIG. 9, the cylindrical stator-side core 12 is
A plurality of coil winding grooves 12a... are formed on the inner circumferential surface, and four signal wires 14... are formed on the outer circumferential surface for guiding the signal wires 14 drawn out along the central axis direction of the stator side core 12. Vertical grooves 12b... are formed.

As shown in FIG. 10(a), the signal wires 14 of the stator side core 12 are brought out from the lower end surface of the stator side core 12 along the vertical grooves 12b, and the In this state, insert the stator side core 12 into the central cylindrical part 1a in the direction of the arrow ↓, as shown in FIG. When the stator side core 12 hits the attached portion 1d, the stator side core 12 is fixed to the central cylindrical portion 1a at this position.

In addition, as described above, the stator side core 1 is attached to the central cylindrical portion 1a.
2. In order to attach the upper bearing 2 and the lower bearing 2', the inside of the central cylindrical portion 1a is machined as described below.

As shown in FIG. 11, a blank 1 that will become the lower drum 1
6 is held and fixed by the clamper 17, the boring bar 18 is inserted into the inside of the blank 16, and the boring tool 19 is brought into contact with the inner peripheral surface of the blank 16 while rotating the blank 16. Cutting is done.

By the way, in order to maintain the rotation of the upper drum 7 with high precision, the inner peripheral surfaces 16a, 16b, and 16b, to which the upper bearing 2, the lower bearing 2', and the stator side core 12 are respectively attached, are provided.
16c requires high coaxiality. For this reason, it is necessary to keep the blank 16 fixed by the clamper 17 in a constant state during processing of each of the inner circumferential surfaces 16a, 16b, and 16c.

[Problem to be solved by the invention]

However, in the rotating magnetic head drum device shown in FIG. 8, as shown in FIGS. 10(a) and 10(b), the edge l
e・1e is formed. Therefore, when assembling the stator side core 12 to the central cylindrical part 1a, as the stator side core 12 is inserted into the central cylindrical part la, the signal wires 14... come into sliding contact with the edges 1e. , signal lines 14... are likely to be damaged or disconnected.

Furthermore, if the magnetic head 6 is added to increase the number of channels as described above, the opposing area of the rotor-side core 11 and the stator-side core 12 in the rotary transformer 13 must be increased. The core 12 necessarily has a long shape in the axial direction. Accordingly, the central cylindrical portion 1a also has a long shape in the axial direction, so when processing the inside of the central cylindrical portion 1a, the length Ll of the blank 16 shown in FIG. 11 must be lengthened.
However, in this case, the inner peripheral surface 16a of the blank 16
In order to cut the material, the length 2 of the boring bar 18 must be increased, which results in insufficient rigidity of the boring bar 18, which causes chatter in the boring tool 19 during cutting, reducing machining accuracy. descend.

[Means to solve the problem]

In order to solve the above problems, a rotating magnetic head drum device according to the present invention consists of a lower drum that is in a fixed state, a drum part that is in a divided state, and a central cylindrical part, and a rotary magnetic head drum device that is provided in the inner lower part of this central cylindrical part. A shaft disposed in the central cylindrical portion is rotatably supported by a lower bearing and an upper bearing provided in a cylindrical portion on the inner circumference side of the drum portion, and the upper drum attached to this shaft via a disk is A magnetic head is provided, and a cylindrical stator-side core attached to the inner circumferential surface of the central cylindrical portion is located between the upper bearing and the lower bearing, and the shaft is disposed opposite to the stator-side core. A rotary transformer consisting of a cylindrical rotor-side core attached to the outer peripheral surface is arranged along the axial direction of the shaft, and furthermore, a rotary transformer is arranged along the axial direction of the shaft. A guide member leading to the outside is attached. It is characterized by

[For production]

In the above configuration, the lower drum is composed of a divided drum part and a central cylindrical part, and the central cylindrical part is not provided with an upper bearing. becomes shorter. Thereby, during machining, it is possible to shorten the boring bar to eliminate the lack of rigidity, suppress chatter that occurs in the boring rebit, and prevent a decrease in machining accuracy. Further, the coaxiality between the inner circumferential surface of the central cylindrical portion and the inner circumferential surface of the cylindrical portion of the drum can be ensured with high precision by adjusting the degree of coaxiality when fixing the drum portion to the central cylindrical portion.

Furthermore, since the guide member is attached to the upper end of the central cylindrical portion, the position at which the signal line of the stator-side core is drawn out to the outside becomes higher. Therefore, by pulling out the signal wire to the outside via the guide member after the stator side core is installed in the central cylindrical portion, it is possible to eliminate the problem that the signal wire is sometimes damaged when attaching the stator side core. In addition, since the lower drum consists of a divided drum part and a central cylindrical part, wiring work can be made easier by fixing the drum part on the central cylindrical part after pulling out the signal line to the outside. be able to.

[Example] An example of the present invention will be described below with reference to FIGS. 1 to 5.

For convenience of explanation, members having the same functions as those of the conventional example will be described with the same reference numerals.

As shown in FIG. 1, the rotating magnetic head drum device includes a lower drum 20 in a fixed state. The lower drum 20 includes a drum section 21 on which the tape runs, and a drum section 2.
1 and a central cylindrical portion 22 supporting the cylindrical portion 1. An upper bearing 2 is provided in the upper part of this central cylindrical part 22,
A lower bearing 2' is provided at the bottom.

The shaft 3 is inserted into the central cylindrical portion 22, and is rotatably supported by the central cylindrical portion 22 via a lower bearing 2'. Further, the shaft 3 has a preload collar 23 attached to the shaft 3 near its lower end protruding downward from the lower bearing 2' to apply an appropriate preload to the shaft 3, and a motor rotor 4 is attached to the lower end. Further, a motor stator 24 is attached to the lower end surface of the central cylindrical portion 22 so as to face the motor rotor 4 .

A disk 5 is externally fitted and fixed to a portion near the upper end of the shaft 3 that protrudes upward from the upper bearing 2. An upper drum 7 is fixed to the outer periphery of the disk 5, and a magnetic head 6 is attached to the lower end surface of the outer periphery of the upper drum 7.

Further, a rotating transformer l is provided on the lower end surface of the disk 5.

A rotor-side core 8 is attached.

On the other hand, the stator-side core 9 of the rotary transformer 10 is attached to the inner bottom surface of the recess of the drum portion 21 of the lower drum 20 so as to face the rotor-side core 8 . The amount of clearance between the rotor-side core 8 and the stator-side core 9 in the rotary transformer 10 is strictly controlled with high precision. Furthermore, the disk 5 is provided with a cylindrical portion 5a at the center of its lower end surface, and is fixedly supported on the inner circumferential surface of the upper bearing 2 via an annular member 25 that is fitted onto the cylindrical portion 5a. ing.

The disk 5 and the upper drum 7 supported in this way are rotatable relative to the lower drum 20,
It is rotationally driven by a motor rotor 4 and a motor stator 24 to rotate together with the shaft 3.

A cylindrical stator-side core 12 is attached to the inner peripheral surface of the central cylindrical portion 22 with its lower end surface abutting against the stepped portion 22a. On the other hand, a cylindrical rotor-side core 11 is formed on the outer peripheral surface of the shaft 3 from the lower end surface of the cylindrical portion 5a to the spacer 2.
6, and is attached so as to face the stator side core 12. A rotor-side core 11 and a stator-side core 12 provided as described above constitute a rotary transformer 13, and the amount of clearance between the rotor-side core 11 and stator-side core 12 is determined by
Similarly, it is strictly controlled with high precision.

On the other hand, in the disk 5, the tube portion 26a of the spacer 26 is inserted into a groove 5b provided along the axial direction of the shaft 3 on the fitting surface with the shaft 3.
A hole 26b penetrating from the tube portion 26a to the lower end is formed in the tube portion 26a. The signal line 27 of the rotor side core 11 is connected to the spacer 2
It is pulled out through the hole 26b of No. 6 and connected to one end of the relay board 28 provided on the upper end surface of the disk 5.

Furthermore, a guide member 29 is provided on the upper end surface of the rotary transformer 13 to hold the signal lines 14 of the stator side core 12 and guide them to the outside. As shown in FIG. 2, the guide member 29 has four arms 29b extending radially around the outer circumference of a lid 29a having an opening in the center, and the ends of the arms 29b. Each section has a tube section 2 extending downward.
9c... is provided. A guide groove 29d for guiding the signal lines 14 to the outside is provided in the arm portion 29b from the inner peripheral portion of the lid portion 29a to the tube portion 29c.

The guide member 29 provided as described above is attached to cover the upper end portion of the stator side core 12 with the lid portion 29a, as shown in FIG. On the other hand, the stator side core 12
The signal line 14... is connected to the guide groove 29d and the pipe portion 29c.
It is pulled out to the outside via. Then, the signal line 14
... is the flange portion 2 of the central cylindrical portion 22 shown in FIG.
It is connected to the relay board 15 attached to the lower end surface of 2b.

As shown in FIG. 4, the central cylindrical part 22 has a guide member fixing part 22 on the upper end surface of a flange part 22b provided at the upper part.
c... and fastening holes 22d... are provided.

The guide member fixing portion 22c consists of a groove provided from the inner peripheral portion of the flange portion 22b to approximately the middle portion thereof, and a hole penetrating from the outer end of this groove to the lower end surface of the flange portion 22b. The guide member 29 has an arm portion 29b attached to the guide member fixing portion 22c provided as described above.
... and is fixed on the flange part 22b by fitting the pipe part 29d. Moreover, the fastening hole 22d...
is a hole through which a fastening member such as a screw is passed in order to fixedly connect the drum part 21 and the central cylindrical part 22.

By the way, since the stator side core 12 and the lower bearing 2' are attached to the central cylindrical part 22 as described above, the inner circumferential surface thereof is attached to the stator side core 12 and the lower bearing 2'.
Processing is performed according to the shape. As shown in FIG. 5, the actual machining is carried out by gripping the blank 30, which will become the central cylindrical part 22, with the clamper 17 and keeping it fixed in a constant state, and inserting the boring bar 18 into the blank 30 while rotating it. By bringing the boring rivet 19 into contact with the inner circumferential surface of the blank 30, the inner circumferential surface 30b to which the lower bearing 2' is attached and the inner circumferential surface 30c to which the stator side core 12 is attached are cut. At this time, even if the axial length L2' of the inner circumferential surface 30c is set shorter than the axial length of the stator side core 12, no structural inconvenience will occur, so the central cylindrical portion 22 is processed. Part length L2
The length l of the boring bar 18 can be shortened by shortening the length l of the boring bar 18. Thereby, the rigidity of the boring bar 18 is not insufficient, and the coaxiality of the inner circumferential surfaces 30b and 30c can be maintained with high precision.

Here, the assembly of the rotating magnetic head drum device configured as described above will be explained.

First, the guide member 29 is attached to the stator-side core 12, and the signal lines 14 of the stator-side core 12 are led out through the guide member 29.

The stator side core 12 with the guide member 29 attached as described above is inserted into the central cylindrical portion 22, and the arm portions 29b of the guide member 29 are attached to the guide member fixing portions 22c of the flange portion 22b. Insert. Further, a lower bearing 2' is fitted and fixed to the lower end of the inner circumference of the central cylindrical portion 22.

By the way, in order to simplify the work when pulling out the signal wires 14 to predetermined positions, it is possible to fit the arm portions 29b into the guide member fixing portions 22c in one way. good. For this purpose, for example, the arm portions 29b and
The width W of one of the arm portions 29b is made larger than the other arm portions 29b, and the groove width of the guide member fixing portion 22c into which the arm portion 29b is fitted is made larger than the width W of the other arm portion 29b. By making the groove width larger than the groove width of the guide member fixing portions 22c..., the fitting position of the arm portions 29b... can be easily determined. Further, as shown in FIG. 6, only one arm portion 29b is provided with a protrusion 29e, and a recess (not shown) corresponding to the protrusion 29e is provided in the corresponding groove of the guide member fixing portion 22c. If you set , as in the above case,
The fitting position of the arm portions 29b can be easily determined.

Next, the shaft 3 is fitted and fixed onto the disk 5, and the annular member 25 is fitted onto the cylindrical portion 5a of the disk 5, and then the spacer 26 is attached. Then, the rotor-side core 11 is inserted into the shaft 3, and the signal line 27 of the rotor-side core 11 is pulled out to the upper end surface of the disk 5 via the spacer 26 and soldered to the relay board 28, and then the rotor-side core 11 is inserted into the shaft 3. Fixed at 3. Further, the rotor-side core 8 of the rotary transformer 10 is attached to the lower end surface of the disk 5.

On the other hand, in the drum part 21, the upper bearing 2 is fitted and fixed inside the cylindrical part 21a, and the stator side core 9 of the rotary transformer 10 is attached to the inner bottom surface of the recess. Then, the shaft 3 to which each member is attached as described above is fitted into the upper bearing 2 and fixed at a predetermined position. Further, the flange portion 22b of the central cylindrical portion 22 is fitted into the lower end recessed portion of the drum portion 21 and temporarily fixed by a fastening member.

In this state, check to see if the axes of the upper bearing 2 and lower bearing 2' are misaligned, causing vibration in the rotation of the shaft 3 and disk 5. If vibration occurs, the upper bearing 2 and the lower bearing 2' to ensure coaxiality, and the drum part 21 and the central cylindrical part 22 are completely fastened and fixed.

Thereafter, the preload collar 23 is inserted and fixed from the lower end of the shaft 3 while applying preload, and the central cylindrical portion 2
The motor stator 24 is fixed to the lower end surface of the shaft 3.
A motor rotor 4 is fixed to the lower end of the motor. Finally, the magnetic head 6 is attached to a predetermined position on the lower end surface of the upper drum 7, and the upper drum 7 is fitted and fixed onto the disk 5.

〔Effect of the invention〕

As described above, in the rotating magnetic head drum device according to the present invention, the lower drum in a fixed state is made up of a divided drum part and a central cylindrical part, and a lower bearing and a drum provided in the inner lower part of the central cylindrical part are connected to each other. A shaft disposed in the central cylindrical part is rotatably supported by an upper bearing provided in the cylindrical part on the inner circumference side of the part, and a magnetic head is provided on the upper drum attached to this shaft via a disk. On the other hand, between the upper bearing and the lower bearing, there is a cylindrical stator-side core attached to the inner circumferential surface of the central cylindrical portion, and a cylindrical stator-side core is attached to the outer circumferential surface of the shaft so as to be opposed to the stator-side core. A rotary transformer consisting of a cylindrical rotor-side core is disposed along the axial direction of the shaft, and a guide member is provided at the upper end of the central cylindrical portion to hold the signal line of the stator-side core and guide it to the outside. is installed.

As a result, the lower drum is made up of a divided drum part and a central cylindrical part, and the central cylindrical part is not provided with an upper bearing. By shortening the length of the boring bar, it is possible to reduce the length of the boring bar, suppress insufficient rigidity, and prevent a decrease in processing accuracy. Further, the coaxiality between the inner circumferential cylinder of the central cylindrical portion and the inner circumferential cylinder of the internal cylindrical portion of the drum portion may be ensured by adjusting when fixing the drum portion to the central cylindrical portion.

On the other hand, since a guide member is attached to the upper end of the central cylindrical portion, the position where the signal line of the stator side core is drawn out to the outside is raised, and the signal line is inserted through the guide member after the stator side core is installed inside the central cylindrical portion. The signal line can be drawn out to the outside, and the problem that the signal line is sometimes damaged when the core is attached to the stator side can be eliminated. Moreover, by fixing the drum part on the central cylindrical part after the signal wires are drawn out, wiring work can be facilitated and assembly workability can be improved.

[Brief explanation of the drawing]

1 to 6 show one embodiment of the present invention, in which FIG. 1 is a longitudinal sectional view showing the structure of a rotating magnetic head drum device, FIG. 2 is a perspective view showing a guide member, and FIG. Figure 3 is a half-sectional view showing the guide member attached to the stator side core, Figure 4 is a perspective view showing the structure of the upper end of the central cylindrical part, and Figure 5 is a diagram showing the machining of the inner peripheral surface of the central cylindrical part. FIG. 6 is a longitudinal sectional view showing the state, and a side view showing the guide member in which the arm portion is provided with a protruding portion. 7 and 11 show conventional examples, in which FIG. 7 is a vertical cross-sectional view showing the configuration of a rotating magnetic head drum device, and FIG. 8 is a rotating magnetic head with wiring attached to the stator side core. FIG. 9 is a vertical cross-sectional view showing the structure of the drum device, FIG. 9 is a perspective view showing the structure of the stator side core, and FIG. 10(a) shows the state of the signal line before the stator side core is inserted into the central cylindrical part. Fig. 11 is a vertical cross-sectional view showing the condition of the signal line when the stator side core is inserted into the central cylindrical part, and Fig. 11 shows the state of machining of the inner circumferential surface of the central cylindrical part. FIG. 2 is the upper bearing IJ ring, 2' is the lower bearing, 3 is the shaft, 5 is the disk, 6 is the magnetic head, 7 is the upper drum,
11 is a rotor side core, 12 is a stator side core, 13 is a rotating transformer, 14 is a signal line, 20 is a lower drum, 21 is a drum portion, 22 is a central cylindrical portion, and 29 is a guide member. Patent applicant Sharp Co., Ltd. Figure Figure 2 Soe 9C 2'':3a Figure Figure 11

Claims (1)

[Claims] 1. The lower drum, which is in a fixed state, consists of a divided drum part and a central cylindrical part, with a lower bearing provided in the lower part of the central cylindrical part, and an upper bearing provided in the cylindrical part on the inner peripheral side of the drum part. A shaft disposed within the central cylindrical portion is rotatably supported, and a magnetic head is provided on an upper drum attached to the shaft via a disk, while between the upper bearing and the lower bearing, A rotary transformer includes a cylindrical stator-side core attached to the inner circumferential surface of a central cylindrical portion, and a cylindrical rotor-side core attached to the outer circumferential surface of the shaft so as to face the stator-side core. A rotating magnetic head disposed along the axial direction of the shaft, further comprising a guide member attached to the upper end of the central cylindrical portion for holding the signal line of the stator side core and guiding it to the outside. drum device.