JP2915054B2 - Rotating head cylinder device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary head cylinder device used for an information recording / reproducing apparatus such as a video tape recorder (VTR) and a digital audio tape recorder (DAT).

[Conventional technology]

Generally, the configuration of a rotary head cylinder device used for a VTR or the like is roughly classified into two types. One type is such that a rotor of a motor and a rotating drum (a rotating drum on which a magnetic head is attached) are fixed to a rotating shaft, and the rotor, the rotating drum and the rotating shaft rotate integrally. Many rotary head cylinder devices are
This type (hereinafter referred to as A type).

In another type, the shaft is fixed to a fixed drum and does not rotate, and the rotating drum is fixed to the outer ring of the bearing, and the rotor of the motor is fixed to the rotating drum. Is a mechanism that rotates integrally with the rotor and the rotating drum, and the present invention is based on a rotating head cylinder device of this outer ring rotating type (hereinafter, referred to as a B type).

FIG. 2 is a cross-sectional view (not shown in the right half) of the B-type rotary head cylinder device in which the shaft is non-rotating and a bearing outer ring attached to the shaft rotates. As shown in the drawing, a motor 2 having a motor stator 1 is fixed to an upper portion of a non-rotating shaft 3, and a fixed drum 4 is fixed to a lower portion of the shaft 3. Between the motor 2 and the fixed drum 4, a ball bearing 6 for mounting the rotating drum 5 is provided.
Are arranged, and the ball bearing 6 is, for example,
A bearing housing 7 made of B _S BM, a bearing outer ring 8 press-fitted into the upper part of the bearing housing 7,
It comprises a bearing outer ring 9 bonded and fixed to a lower portion in the bearing housing 7, and a plurality of balls 10, 11 rolling between the bearing outer ring 8, the bearing outer ring 9, and the shaft 3. In order to reduce the distance between the two bearings, a shaft-integrated bearing having no preload means such as a coil spring or a wave washer is used. The rotating drum 5 is fixed to the upper portion of the bearing housing 7 by the screw 5a as described above, and a motor rotor 13 is mounted in the recess 12 of the rotating drum 5 so as to face the motor stator 1 and rotate. The drum 5 is driven to rotate. A magnetic head support member 15 having a magnetic head 14 is fixed to the lower surface of the rotating drum 5 with screws 15a.

A rotary transformer 16 is interposed between the fixed drum 4 and the rotary drum 5.
Transmits an information signal read from the magnetic tape 17 by the magnetic head 14 to the fixed drum 4 side. The rotary transformer 16 is adhered and fixed to the lower portion of the bearing housing 7 and adheres to a disc-shaped rotary transformer rotor 19 having concentric coils 18a and 18b interposed therebetween and an inner bottom surface 20 of the fixed drum 4. There is a disk-shaped rotary transformer stator 22 which is fixed and has concentric coils 21a and 21b opposed to the coils 18a and 18b, respectively.

In the rotary head cylinder device configured as described above, since the motor rotor 13 rotates with respect to the motor stator 1 of the motor 2, the rotation driving force of the motor rotor 13 causes the rotary drum 5 and the bearing housing to rotate. 7 and the rotary transformer rotor 19 rotate together with the bearing outer rings 8 and 9. A connector 24 made of resin mold is adhered and fixed on the upper surface of the rotor 19 for the rotary transformer, and each winding of the rotor 19 for the rotary transformer is soldered to the connector 24. The spring material of the connector 24 is
The rounded portion of the magnetic head support member 15 having a contact is provided, and the connector 24 and the round portion of the magnetic head support member 15 are plated with gold to improve the electrical conductivity. Therefore, the information signal from the magnetic tape 17 is transmitted to the magnetic head 14 rotating together with the rotating drum 5.
The signal is transmitted to the magnetic head support member 15 and further transmitted from the round portion of the magnetic head support member 15 to the connector 24 and sent to the rotary transformer 16.

[Problems to be solved by the invention]

In the conventional rotary head cylinder device, either one of the outer rings of the shaft-integrated bearing is fitted and bonded and fixed to the housing 7 with a clearance at a constant temperature in a state of being maintained. For this clearance, the upper and lower outer rings 8,9
Is difficult to fix coaxially with respect to the shaft 3, and as a result, the bearing housing 7 swings.
For this reason, additional processing such as cutting is required for the purpose of improving runout accuracy with reference to the shaft 3. It was difficult to mount the magnetic head 14 directly on the bearing housing 7 due to poor runout accuracy, and the bearing housing 7 and the rotary drum 5 had to be separated. in this way,
A rotary drum 5 on which the magnetic head 14 is mounted, a bearing housing 7 for mounting the rotary drum 5,
Since the rotary transformer rotor 19 attached to the bearing housing 7 is a separate member, the magnetic head 14 and the rotary transformer rotor 19
In order to transmit and receive signals to and from the device, it is necessary to provide a connector 24 for connection, and this has a problem that the structure is complicated and the assembly process is also complicated.

In addition, the magnetic head 14 is required to have strict positioning in the radial direction, the vertical direction, and the like, and the positioning of the rotary transformer 16 with respect to the magnetic head 14 must be strictly performed. After finely adjusting and assembling the positions of the bearing housing 7, the rotary transformer 16, the fixed drum 4 and the like, the magnetic head 14 and the rotary transformer rotor 19 must be connected by the connector 24. Member.

The present invention has been made to solve such a problem, and an object of the present invention is to provide a rotary head cylinder device capable of reducing the number of components and simplifying the structure.

[Means for solving the problem]

A rotary head cylinder device according to the present invention includes a fixed drum fixed to a non-rotating shaft, a rotary drum attached to the shaft and driven to rotate and provided with a magnetic head, and a rotary drum provided with a magnetic head. And a signal transmission means such as a rotary transformer for transmitting and receiving a signal of recording or reproduction to and from the magnetic head, the shaft-integrated bearing having no preload means such as a coil spring or a wave washer. The upper and lower outer rings are fitted and held on a rotating drum so as to shrink at a constant temperature.

[Action]

According to the present invention, the upper and lower outer rings of a shaft-integrated bearing having no preload means such as a coil spring and a wave washer are fitted and held on a rotating drum so as to shrink at a constant temperature, thereby simultaneously fixing the upper and lower outer rings. Thus, the run-out accuracy of the rotary drum is improved, the magnetic head can be directly fixed to the rotary drum, and the bearing housing and the rotary drum to which the magnetic head is fixed can be integrated.

〔Example〕

Hereinafter, an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a longitudinal sectional view of a rotary head cylinder device according to the present embodiment, in which a left half in the figure shows a magnetic head mounting part, and a right half in the figure shows a rotary transformer mounting part to a rotating body. It has a cross section.

The rotary head cylinder device shown is of the B type in which the shaft is non-rotating and the bearing outer ring attached to this shaft rotates, as in FIG. The apparatus of the present embodiment is characterized in that a rotary drum as a rotary body in which the rotary drum and the bearing housing are integrated is provided. As shown, an upper end of a non-rotating shaft 53 is fixed to a motor 52 having a motor stator 51, and a fixed drum 54 is fixed to a lower portion of the shaft 53. A rotary drum 55 attached to a shaft 53 and driven to rotate is disposed between the motor 52 and the fixed drum 54.
A bearing outer ring 58 is press-fitted into the upper part inward so as to be shrunk at a constant temperature, and a bearing outer ring 59 is fixed to an inner lower part so as to shrink at a constant temperature. Further, the smaller diameter sides of the upper and lower outer rings 58, 59 are reinforced with an adhesive. This is because the thermal expansion difference between the housing (rotary drum 55) and the bearing outer rings 58 and 59 may cause clearance at high temperatures. In this case, the shaft-integrated bearing without preload means such as coil springs and wave washers This configuration is intended to prevent the possibility of a decrease in preload. A plurality of balls 6 are provided between the bearing outer rings 58 and 59 and the shaft 53.
0,61 rolls. In this configuration, a springless shaft bearing is used to reduce the distance between the two bearings. A motor rotor 63 is mounted in the concave portion 62 at the upper part of the rotating drum 55 so as to face the motor stator 51 so as to rotate the rotating drum 55. A magnetic head 64 is provided on the lower surface of the rotating drum 55.
Is fixed by screws 65a.

A rotary transformer 66 as a signal transmission means is interposed between the fixed drum 54 and the rotary drum 55. The rotary transformer 66 transmits and receives a recording signal or a reproduction signal to and from a magnetic head 64 that contacts a magnetic tape 67. And the recording signal is received from the fixed drum 54 side, or the reproduction signal is transmitted to the fixed drum 54 side. Also,
The rotary transformer 66 has a disk-shaped rotary transformer rotor 69 that is adhesively fixed to a lower portion of the rotary drum 55 and has concentric coils 68a and 68b interposed therebetween, and a fixed drum 54.
Adhesively fixed on the inner bottom surface 70, and the coils 68a, 68b
And a disk-shaped rotary transformer stator 72 having concentric coils 71a and 71b facing each other. Further, an FG pattern for detecting the number of rotations and controlling the rotation of the motor 52 at a constant speed is arranged inside the rotary transformer 66, and a detection signal detected by the FG pattern is provided below the rotary transformer 66. Is output from the side to the outside. The lead wire 76 of the rotary transformer rotor 69 is directly connected to the round portion of the magnetic head support member 65 by means such as soldering, so that a signal is transmitted between the magnetic head 64 and the rotary transformer rotor 69. To give and receive. Therefore, in this embodiment, a connector for connecting the lead wire 76 to the magnetic head support member 65 is not required.

Next, the operation will be described. When the motor 52 is turned on, the motor rotor 63 disposed opposite to the motor stator 51 is driven to rotate, and together with the motor rotor 63, the rotating drum 55 and the bearing outer rings 58 and 59 are rotated through non-rotating shafts via balls 60 and 61. Rotate around 53. On the other hand, the fixed drum 54 and the rotary transformer stator 72 fixed to the shaft 53 are stationary, while the rotary transformer rotor 69 fixed to the rotary drum 55 rotates. Therefore, an information signal (for example, a reproduction signal) transmitted from the magnetic tape 67 to the magnetic head 64 flows through the magnetic head support member 65 and the lead wire 76 and is transmitted to the rotor 69 for the rotary transformer.
The information signals are processed by the coils 68a, 71a and 68b, 71b and then transmitted to an external circuit.

As described above, in this embodiment, since the upper and lower outer rings 58, 59 of the shaft-integrated bearing are fixed to the housing (the rotating drum 55) so as to shrink at a constant temperature, the upper and lower outer rings 58, 59 with respect to the shaft 53. Since the shaft rotates coaxially, the runout accuracy is improved. In addition, since the rotating drum 55 serves both as a conventional rotating drum and a bearing housing, the rotating drum 55
The magnetic head 64 and the rotor 69 for the rotary transformer can be fixed to the rotary head cylinder device. Also,
It is not necessary to assemble the rotating drum with the bearing housing, which is conventionally required, and no positional error occurs between the two members. Further, since a connector is not required, the number of parts is further reduced, and the connection work from the magnetic head 64 to the rotary transformer 66 is facilitated.

The present invention is applicable to either signal processing of recording or reproduction, or signal processing of both recording and reproduction.

〔The invention's effect〕

As described above, the present invention improves the runout accuracy by fixing the upper and lower outer rings of the shaft-integrated bearing to the housing so as to be shrunk at a constant temperature, and the rotating drum is different from the conventional rotating drum. Since it can also be used as a bearing housing, a connector which has been conventionally required is not required, and the number of components of the apparatus can be reduced, so that the entire apparatus can be reduced in size and thickness. In addition, since no connector is required, the connection work becomes easy.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a rotary head cylinder device showing an embodiment of the present invention, and FIG. 2 is a one-side longitudinal sectional view showing a conventional rotary head cylinder device. 53 ... shaft, 54 ... fixed drum, 55 ... rotating drum, 58,59 ... bearing outer ring, 64 ... magnetic head, 66 ... signal transmission means (rotary transformer).

Claims (1)

(57) [Claims] A fixed drum fixed to a non-rotating shaft, a rotating drum attached to the shaft and driven to rotate and provided with a magnetic head, and a rotary drum interposed between the rotating drum and the fixed drum; In a rotary head cylinder device provided with a signal transmission means such as a rotary transformer for transmitting and receiving a signal of recording or reproduction to and from the magnetic head, the upper and lower outer rings of a shaft-integrated bearing having no preload means such as a coil spring or a wave washer. In addition, the rotary head cylinder device is fitted and held on the rotary drum so as to cause shrinkage at a constant temperature.