JPH06236501A - Rotary drum rotary transformer adjustment mechanism - Google Patents

Abstract

(57) [Abstract] [Purpose] To minimize the deviation between the relay board of the video head and the contact terminal of the rotary transformer, and to accurately determine the air gap between the rotary transformer rotor and the rotary transformer stator. [Structure] A fixed shaft type drum is used, in which the rotating upper drum part and the bearing part are integrated, and the video head is directly attached.
On the other hand, in the rotary transformer rotor 7, a contact terminal 9 is insert-molded into a rotary transformer holder 8 provided with a longitudinal guide cylindrical portion for adjusting a gap between the rotary transformer rotor 7 and the rotary transformer stator 6 and a fixing portion by screwing. And the guide cylinder portion provided on the outer peripheral surface 2a of the bearing portion of the upper drum 2 are fitted with a gap, which enables a minute movement in the longitudinal direction, and the gap of the rotary transformer can be adjusted. The rotation phase of the relay board and the contact terminal 9 can be set only at one position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary transformer adjusting mechanism for a rotary drum, and more particularly to a VTR (Vi
A rotary drum device having a plane-opposing rotary transformer of a magnetic recording / reproducing device mounted on a dio tape recorder, etc., wherein the connection between the video head and the rotary transformer is performed by contact terminals, and the contact terminals are insert-molded. The present invention relates to a rotary transformer adjusting mechanism capable of adjusting a gap by finely moving a rotary transformer holder integrated with the above-mentioned cylinder guide surface on the outer circumference of a bearing.

[0002]

2. Description of the Related Art FIGS. 5 and 6 are block diagrams of a conventional rotary drum, FIG. 5 is a sectional view, and FIG. 6 is a plan view of a video head and a contact terminal portion. In the figure, 41 is a lower drum, 42 is an upper drum, 43 and 44 are ball bearings, 45 is a drum shaft,
46 is a disk, 47 is a rotary transformer stator,
48 is a rotary transformer rotor, 49 is a rotary transformer holder, 50 is a contact terminal, 51 is a video head,
52 is a preload collar, 53 is a DD (direct drive) motor rotor, 54 is a DD (direct drive) motor stator, 55 is a drum base, 56 is a step adjusting screw,
57 is a mounting screw, 58 is a gap, 59 and 60 are mounting screws,
Reference numeral 61 is a relay board, and 62 is a mounting screw.

In FIG. 5, a ball bearing 4 is attached to the lower drum 41.
3, 44 are fixed by shrink fitting. A rotary transformer stator 47 is fixed to the lower drum 41 by adhesion or the like. On the other hand, a drum shaft 55 is fixed to the disc 46 by shrink fitting, and the drum shaft 45 is fitted into the inner rings of the ball bearings 43 and 44 with a clearance. Further, in order to remove the play in the axial direction of the bearing, a constant pressure is applied by the preload collar 52 to form the bearing portion. Further, a rotary transformer holder 49 is fixed to the rotary transformer rotor 48 by adhesion, and a contact terminal 50 for electrically connecting the rotary transformer rotor 48 and the video head 51 is fixed to the rotary transformer holder 49 by insert molding or the like. There is.

FIG. 6 is a plan view of a video head and contact terminals. For connection between the video head 51 and the rotary transformer rotor 48, a method has conventionally been adopted in which a pin, a lead wire or the like is once pulled out above the upper drum 42 and relayed (connected) here. Recently, a contact method as shown in FIG. 5 has been adopted from the viewpoints of troublesomeness such as removing soldering and reduction of the number of parts assembling. In FIG. 6, the upper drum 42 and the video head 51
Are attached with a predetermined accuracy by attaching screws 62. In addition, the relay board 61 of the video head 51 relays the winding from the video head, and the contact terminal 50 connects the rotary transformer rotor. What is important here is a shift in the rotation direction between the contact terminal 50 and the relay board 61 of the video head 51.

Returning to FIG. 5, the rotary transformer holder 49 and the contact terminals 50 attached to the rotary transformer rotor 48 are positioned on the disk 46 in the rotational direction and fixed by adhesion or the like. On the other hand, a video head 51 is attached to the upper drum 42 with attachment screws 57 with a predetermined accuracy. The step adjusting screw 56 is for finely adjusting the height of the video head 51. Further, below the lower drum 41, a DD motor stator 54 and a DD motor rotor 53 are mounted at predetermined positions by mounting screws 60 or the like. Further, the rotary transformer rotor 48 and the rotary transformer stator 47
In order to determine the gap, the heights from the upper surface of the rotary transformer stator 47 to the inner ring end surface of the ball bearing and the height of the end surface of the disk 46 and the lower surface of the rotary transformer rotor 48 are measured so that an appropriate gap can be obtained. A gap shim having a predetermined thickness is inserted into the gap 58 between the inner ring of the ball bearing 44 and the disc 46.

The assembly of the rotary transformer rotor 48 (the rotary transformer rotor 48, the rotary transformer holder 49, and the contact terminal 50) is a disk 46.
The upper drum 42 is further attached to the disc 46 with a mounting screw 59 so as to have a predetermined deflection accuracy. When the drum shaft 45 is used as a reference, the radial runout of the drum shaft 45 and the drum shaft 45
From the point of fitting of the upper drum 42, concentric adjustment is often performed as a clearance fit to adjust the outer drum outer peripheral runout to a predetermined accuracy. In such a case, there is a problem in that the contact terminals 50 and the relay board 61 of the video head 51 shown in FIG.

[0007]

As described above, in the conventional rotating drum, the rotary transformer and the video head are connected to each other inside the drum by the conventional method of drawing the lead drum to the upper portion of the upper drum with a lead wire or the like and relaying the lead wire there. In the "contact terminal type" drum that enables electrical connection,
In order to match the rotational position of the contact terminal with the pattern (land) of the relay board of the video head, it was necessary to match the phases of the rotary transformer holder and the disc, and the disc and the upper drum. In the conventional rotary transformer gap adjustment method, it is necessary to measure the dimensions of the two assemblies and then select the appropriate gap shim, which requires not only many types of gap shims but also assembly workability. There were many problems such as bad.

The present invention has been made in view of the above circumstances, and suppresses the deviation between the relay board of the video head and the contact terminal of the rotary transformer, and reduces the air gap between the rotary transformer rotor and the rotary transformer stator. It is an object of the present invention to provide a rotary transformer adjusting mechanism for a rotary drum, which can be accurately determined.

[0009]

In order to solve the above-mentioned problems, the present invention provides (1) a rotary drum having a magnetic head for recording / reproducing on / from a magnetic tape, wherein a signal from the magnetic head is sent to a circuit side. A plane-opposing rotary transformer for transmission, a contact-type contact terminal for electrically connecting the plane-opposing rotary transformer rotor and a magnetic head, and a combination of the contact terminal and the plane-opposing rotary transformer rotor. Coupling member, a guide cylindrical portion that guides the coupling member and is arranged concentrically with the rotation shaft, and the coupling member can be slightly moved in the longitudinal direction of the guide cylindrical portion, and is retained by the guide cylindrical portion. With a holding mechanism that can
The feature is that the air gap of the rotary transformer can be adjusted.

[0010]

The upper drum of the fixed shaft type drum is provided with a bearing portion, and the outer peripheral portion of the bearing portion is provided with a guide cylindrical portion for clearance fitting with the rotary transformer rotor holder and a screw portion for stopping the holder. Since the contact terminal is integrated by insert molding in the rotary transformer holder that fits in the cylindrical part, and the flat facing rotary transformer is bonded to this, the rotation phase between the contact terminal and the relay board of the video head mounted on the upper drum It is possible to easily obtain accuracy and easily adjust the air gap of the rotary transformer.

[0011]

Embodiments will be described below with reference to the drawings. FIG. 1 is a configuration diagram (cross-sectional view) for explaining an embodiment of a rotary transformer adjusting mechanism for a rotary drum according to the present invention, in which 1 is a lower drum, 2 is an upper drum, and 2a is a bearing portion outer peripheral surface. , 3 and 4 are ball bearings, 5 is a drum shaft,
6 is a rotary transformer stator, 7 is a rotary transformer rotor, 8 is a rotary transformer holder, 9 is a contact terminal, 10 is a video head, 11 is a preload collar, 12 is a DD (direct drive) motor rotor, and 13 is a DD.
(Direct Drive) Motor Stator, 14 is a mounting screw, 15 is a step adjusting screw, 16, 17 and 18 are mounting screws, 19 is a drum base, and 20 is a relay board.

The lower drum 1 is a fixed drum, and a drum shaft 5 is attached in the vicinity of the center of the lower drum 1 with high precision by shrink fitting. A rotary transformer stator 6 is attached to the lower drum 1 by adhesion or the like. On the other hand, the upper drum 2 is provided with a bearing portion in which the ball bearings 3 and 4 are fitted by shrink fitting or the like. The outer peripheral surface 2a of the bearing portion of the upper drum 2 serves as a guide surface for a rotary transformer holder 8 described later, and is machined with a predetermined dimensional accuracy. The upper drum 2 having a bearing portion composed of the above-mentioned ball bearings 3 and 4 is attached to the drum shaft 5 so that the inner rings of the ball bearings 3 and 4 are fitted in a clearance. The bearing is constructed by applying a constant force by the preload collar 11 in order to eliminate the play in the slant direction of the ball bearing. Further, a video head 10 is attached to the upper drum 2 by a mounting screw 14 with a predetermined accuracy. Also, a screw for adjusting the level difference 1
Reference numeral 5 is for finely adjusting the height of the video head 10. Further, a DD motor rotor 12 is attached to the upper drum 2, and a DD motor stator 13 is attached to the preload collar 11 with a mounting screw 17.
Further, the rotary transformer rotor 7 is fixed to a rotary transformer holder 8 by adhesion, and the rotary transformer holder 8 has the outer peripheral surface 2a of the bearing portion of the upper drum described above.
And the lower drum 2 are assembled, and then the rotary transformer stator 6
The position is fixed by mounting screws 16 so that the air gap of the rotary transformer rotor 7 becomes a predetermined amount. Furthermore, a connection terminal 9 for electrically connecting the winding of the rotary transformer rotor 7 and the winding of the video head 10 is attached to the rotary transformer holder 8 by insert molding.

FIG. 2 is a plan view of the video head and connection terminals of FIG. 1. In the figure, 21 is a relay board, 22 is a mounting screw, and other parts having the same functions as those in FIG. Is attached. The shaded area represents the pattern of the relay board 21 of the video head 10. As for the phase relationship between the land of the relay board 21 of the video head 10 and the contact terminal 9, a deviation in the rotation direction is particularly likely to occur.

FIG. 3 and FIG. 4 are enlarged views of the rotary transformer holder, which has a structure capable of suppressing the displacement in the rotational direction as much as possible. FIG. 3 is an enlarged view of only the bearing portion, and FIG. 4 is a view seen from an arrow A in FIG. In the figure, 30 is a bearing part, 31, 32
Is a ball bearing, 33 is a drum shaft, 34 is a rotary transformer rotor, 35 is a rotary transformer rotor holder, 35a is an elongated hole, 36 is a mounting screw, and 36a is a screw outer diameter. The drum shaft 33 is fitted in the ball bearing 32 with a clearance. The bearing portion 30 is integrated with an upper drum (not shown). A rotary transformer rotor holder 35 is fitted on the outer peripheral guide surface of the bearing portion 30 so as to make a slight movement in the longitudinal direction, and a rotary transformer rotor 34 is fixed to the rotary transformer rotor holder 35 by adhesion. The contact terminal portion is omitted. The mounting screw 36 is a rotary transformer rotor holder 35.
For fixing the screw, and has a substantially same diameter as the elongated hole 35a in the longitudinal direction and the screw outer diameter 36a in the rotating direction. Figure 4 is a simpler illustration of this situation. The screw outer circumference 36a indicates the outer diameter of the mounting screw 36, and the rotary transformer rotor holder 35 has a long hole 35a in the longitudinal direction of the shaft.
Is provided.

As described above, the present invention has a contact type contact terminal for electrically connecting the plane-opposing rotary transformer rotor and the magnetic head, and fixes the contact terminal to the rotary transformer rotor. A holder is provided, and the holder is configured to be capable of being slightly moved along the outer peripheral surface of a cylindrical guide portion arranged concentrically with the rotating shaft.
The holder can be moved slightly in the longitudinal direction of the cylindrical guide,
The air gap of the rotary transformer can be adjusted by fixing it with mounting screws. In the present invention, this holder has two functions of gap adjustment and contact terminal holding, and at the same time, since this holder is directly attached to the upper drum to which the magnetic head is attached, the pattern of the relay substrate of the magnetic head and the contact terminal are provided. This is to reduce the deviation.

[0016]

As is apparent from the above description, the present invention has the following effects. That is, in a shaft-fixed rotary drum, the electrical connection between the video head and the rotary transformer rotor is made into a contact terminal system, and the contact terminal is insert-molded into the rotary transformer holder to be integrated, and the rotary transformer holder is provided on the upper drum. Since it is movable by guiding to the outer peripheral surface of the bearing part, it is possible to suppress the deviation between the relay board of the video head and the contact terminal of the rotary transformer, and
There are many advantages in that the air gap between the rotary transformer rotor and the rotary transformer stator can be accurately determined.

[Brief description of drawings]

FIG. 1 is a configuration diagram for explaining an embodiment of a rotary transformer adjusting mechanism for a rotary drum according to the present invention.

FIG. 2 is a plan view of a video head and a contact terminal portion in FIG.

FIG. 3 is an enlarged view of the vicinity of the bearing of the present invention.

FIG. 4 is a view on arrow A in FIG.

FIG. 5 is a configuration diagram of a conventional rotary drum.

FIG. 6 is a plan view of the video head and contact terminal portion in FIG.

[Explanation of symbols]

1 ... Lower drum, 2 ... Upper drum, 2a ... Bearing part outer peripheral surface,
3, 4 ... Ball bearing, 5 ... Drum shaft, 6 ... Rotary transformer stator, 7 ... Rotary transformer rotor, 8
... Rotary transformer holder, 9 ... Contact terminal, 10 ... Video head, 11 ... Preload collar, 12 ... DD (direct drive) motor rotor, 13 ... DD (direct drive) motor stator, 14 ... Mounting screw, 15 ... Step adjustment Screws, 16, 17, 18 ... Mounting screws, 19 ... Drum base, 20 ... Relay board.

Claims (1)

[Claims] 1. A rotary drum provided with a magnetic head for recording / reproducing on / from a magnetic tape, and a plane-opposed rotary transformer for transmitting a signal from the magnetic head to a circuit side, and the plane-opposed rotary transformer rotor. And a contact type contact terminal for electrically connecting the magnetic head with
A coupling member for coupling the contact terminal and the flat-faced rotary transformer rotor, a guide cylindrical portion which is arranged concentrically with the rotating shaft and guides the coupling member, and the guide cylindrical portion in the longitudinal direction. A rotary transformer adjusting mechanism for a rotary drum, comprising: a holding mechanism capable of finely moving the coupling member and holding the guide member in the guide cylindrical portion, and enabling adjustment of an air gap of the rotary transformer.