JP3089903U - Rotating magnetic head device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To mount a thrust bearing and a face plate portion of a rotor frame on the basis of a single mounting surface formed on the upper surface of a rotary drum, thereby providing a space between the rotor frame and the thrust bearing. Maintain high parallelism. SOLUTION: When a thrust bearing 52 and a rotor frame 71 of a motor 7 are screwed to a rotary drum 2 supported on a support shaft 3 via a radial bearing 51, a face plate 73 of the rotor frame 71 and a thrust bearing are fixed. 52, and the overlapping portion is screwed to the mounting surface 22 on the upper surface of the rotary drum 2 using a mounting screw 64. If the rotary drum 2 is a die-cast molded body, the unprocessed ground surface provided on the molded body can be used as the mounting surface 22 as it is.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to a rotary magnetic head device used for a magnetic tape device, and more particularly to a rotary magnetic head device having a structure in which a rotary drum having a magnetic head is supported by a fixed shaft as a fixed shaft via a radial bearing and a thrust bearing. .

[0002]

[Prior art]

 Japanese Patent Application Laid-Open No. 62-167606 (Prior Art 1) discloses that a rotating member (rotating drum) having a magnetic head rotatably supported on a fixed shaft (support shaft) is pressed axially by the fixed shaft. It is described that a thrust bearing for imparting power is screwed with a mounting screw, and a rotor case (rotor frame) of a motor for driving a rotating member is screwed to the rotating member with another mounting screw. . A similar configuration is described in Japanese Patent Application Laid-Open No. 4-95206 (Prior art 2). In the first and second examples, the thrust bearing is fixed to the upper surface of the rotating drum, and the rotor case is fixed to the lower surface of the rotating drum.

On the other hand, in a rotating magnetic head device, an attempt has been made to dispose a motor above a rotating drum and fix a rotor frame of the motor to a mounting surface formed on an upper surface of the rotating drum. This rotary magnetic head device is shown in FIGS. 4 to 6, wherein FIG. 4 is a schematic longitudinal sectional view of the rotary magnetic head device, FIG. 5 is a plan view of a main part, and FIG. 6 is an enlarged cross-sectional view of the main part.

In FIG. 4, reference numeral 1 denotes a fixed drum having a lead groove 11 for guiding a tape (not shown). Reference numeral 2 denotes a rotary drum, and 3 denotes a support shaft. The lower end of the support shaft 3 is fixed to the fixed drum 1. The rotary drum 2 includes a magnetic head 4, and radial bearings 51 are mounted in two positions above and below the central through hole 21 in a press-fit state, and the radial bearings 51 are fitted to the support shaft 3. On the other hand, as shown in FIG. 4 or FIG. 5, the rotating drum 2 is divided into a flat inner peripheral mounting surface 22a and a flat outer peripheral mounting surface 22b with the upper surface bordering the annular projection 23. A disc-shaped thrust bearing 52 is superimposed on the inner peripheral side mounting surface 22a, and the thrust bearing 52 is screwed to the rotary drum 2 by a mounting screw 61 at the overlapping portion. An annular face plate 73 provided on the rotor frame 71 of the motor 7 disposed above the rotary drum 2 is superimposed on the outer peripheral side mounting surface 22b, and the rotor frame 71 is attached to the rotary drum 2 at the overlapping portion. It is screwed by a mounting screw 62. The stator 72 of the motor 7 is attached to the upper plate 81 of the support 8, which is attached to the fixed drum 1 and extends above the rotary drum 2. A pressing pin 82 is attached to the upper plate portion 81, and the pressing pin 82 presses the thrust bearing 52 by the bias of the spring body 83 to press the support shaft 3 in the axial direction.

In this rotary magnetic head device, the rotary drum 2 was made of a die-cast body made of an aluminum alloy. In addition, in order to suppress problems such as vibration and rotation unevenness during rotation of the rotating drum 2, it is necessary to align the axial lines of the thrust bearing 52 and the rotor frame 71 with high precision to increase the parallelism between the two. It is. For this reason, despite the fact that a die-cast molded body having excellent dimensional accuracy is used for the rotary drum 2, the inner peripheral side mounting surface 22 a and the outer peripheral side mounting surface 22 b of the rotary drum 2 are formed on the upper surface of the above-mentioned molded body. By cutting the ground surface to a higher degree of accuracy, such a finishing process increases the degree of parallelism between the inner peripheral side mounting surface 22a and the outer peripheral side mounting surface 22b of the rotating drum 2 so as to mount them. The parallelism between the thrust bearing 52 and the face plate 73 of the rotor frame 71, which are superimposed on the surfaces 22a and 22b and screwed by separate mounting screws 61 and 62, is secured.

[0006]

[Problems to be solved by the invention]

 However, in the rotary magnetic head device described with reference to FIGS. 4 to 6, each of the thrust bearing 52 and the rotor frame 71 has the inner peripheral side mounting surface 22 a formed on the upper surface of the rotary drum 2 and the outer peripheral side. Since the screws are overlapped on the mounting surface 22b and screwed, the parallelism between the thrust bearing 52 and the rotor frame 71 is determined with high precision. In addition to this, there is a problem that not only requires a great deal of time and labor, but also requires a high production cost.

[0007] The ones described in the first and second prior art examples also have the same problem because the thrust bearing is fixed to the upper surface of the rotating drum and the rotor case is fixed to the lower surface of the rotating drum. .

[0008] The present invention has been made in view of the above problems, and a motor is disposed above a rotating drum, and both a thrust bearing and a rotor frame of the motor are screwed to the upper surface of the rotating drum. It is an object of the present invention to provide a rotary magnetic head device in which the parallelism between a thrust bearing and a face plate of a rotor frame of a motor is reliably determined with reference to a single mounting surface formed on the upper surface of a rotary drum when mounting by rotating. .

Further, the present invention provides a rotary magnetic head device which can reduce or omit the time and effort of cutting and finishing the upper surface of the rotary drum, and can also reduce the manufacturing cost. With the goal.

[0010] Further, the present invention provides a rotating magnetic head which can be attached to a thrust bearing without using extra parts when the rotating drum is connected to the earth via an earth electrode attached to the thrust bearing. It is intended to provide a device.

[0011]

[Means for Solving the Problems]

 The rotary magnetic head device according to the present invention comprises a rotating drum having a magnetic head rotatably supported on a support shaft via a radial bearing, a thrust bearing for pressing the support shaft in the axial direction, and a motor rotor frame. In the rotary magnetic head device, the face plate portion of the rotor frame and the outer peripheral portion of the thrust bearing are overlapped with each other, and the thrust bearing and the rotor frame of the motor are attached to the rotating drum. Each of the mounting screws, which are screwed, is screwed onto a flat mounting surface formed by the upper surface of the rotary drum so that an overlapping portion between the inner peripheral portion of the face plate portion of the rotor frame and the outer peripheral portion of the thrust bearing is formed. It is replaced by the mounting screws that are being stopped.

According to this invention, both the face plate portion of the rotor frame and the outer peripheral portion of the thrust bearing are screwed to a single flat mounting surface formed on the upper surface of the rotating drum. Serves as a reference plane that determines the parallelism of both the face plate of the rotor frame and the thrust bearing. Therefore, the parallelism between the face plate portion of the rotor frame and the thrust bearing is determined with high accuracy. Therefore, it is possible to reduce or omit the trouble of cutting and finishing the upper surface of the rotating drum, and also to reduce the cost required for the cutting and finishing process on the upper surface of the rotating drum, thereby reducing the manufacturing cost. It will work. Furthermore, the number of mounting screws required for screwing the thrust bearing and the motor rotor frame to the rotating drum is reduced, so that the number of parts is reduced and the cost is easily reduced.

In the present invention, it is desirable that the face plate of the rotor frame be superimposed on the mounting surface, and the outer peripheral portion of the thrust bearing be superimposed on the upper surface of the face plate. In other words, by simply forming the entire upper surface of the rotating drum on a flat mounting surface and forming the face plate of the rotor frame flat, the overlapping area between the face plate of the rotor frame and the mounting surface of the rotating drum can be reduced. It is possible to secure a wide space and improve the stability of mounting the rotor frame to the rotating drum.

In the present invention, an electrode plate as a ground electrode on which the brush electrode slides is superimposed on the upper surface of the thrust bearing, and the electrode plate is formed by an inner peripheral portion of the rotor frame and an outer peripheral portion of the thrust bearing. Is preferably screwed to the thrust bearing by the mounting screw screwing the overlapping portion to the upper surface of the rotary drum. According to this, the rotary drum is connected to the thrust bearing via a ground electrode. In the case of earth connection, the earth electrode can be attached to the thrust bearing with the attachment screw for attaching the rotor frame and the thrust bearing to the rotating drum, so that an extra attachment screw for attaching the electrode plate is not required.

In the rotary magnetic head device according to the present invention, a rotating drum having a magnetic head rotatably supported on a support shaft via a radial bearing is provided with a thrust bearing for axially pressing the support shaft and a motor. In the rotary magnetic head device in which the rotor frame and the rotor frame are screwed by separate mounting screws, the outer peripheral portion of the thrust bearing is overlapped on the upper surface of the inner peripheral portion of the face plate portion of the rotor frame, and the upper surface of the thrust bearing is provided. An electrode plate as an earth electrode on which the brush electrode slides is overlapped, and each of the mounting screws for screwing the thrust bearing and the rotor frame of the motor to the rotating drum is attached to the rotor. A flat mounting surface formed by the upper surface of the rotary drum, where the overlapping portion between the face plate portion of the frame, the outer peripheral portion of the thrust bearing, and the electrode plate is formed. The rotary drum is a metal die-cast molded body, and the molded body has the mounting surface where the inner peripheral portion of the face plate of the rotor frame overlaps. It is possible to adopt a configuration in which the surface is an unprocessed ground surface. According to this, in addition to the above-described operations, the parallelism between the thrust bearing and the rotor frame is determined with high accuracy, even though it is not necessary to finish the upper surface of the rotating drum, and the vibration and vibration of the rotating drum are reduced. This makes it possible to suppress rotation unevenness and improve image quality stability.

[0016]

[Embodiment of the invention]

 FIG. 1 is a schematic longitudinal sectional view showing an embodiment of a rotary magnetic head device according to an embodiment of the present invention, FIG. 2 is a plan view of a main part, and FIG. 3 is a longitudinal sectional side view showing an enlarged main part.

When the rotary magnetic head device of this embodiment is compared with the rotary magnetic head device described with reference to FIGS. 4 to 6, the mounting structure of the thrust bearing 52 and the rotor frame 71 of the motor 7 with respect to the rotary drum 2 and the upper surface of the rotary drum 2 The shape of the formed mounting surface 22 is different. Hereinafter, these matters will be mainly described.

As shown in FIG. 1 or FIG. 3, almost the entire upper surface of the rotary drum 2 is formed as a flat mounting surface 22, and a ring-shaped ridge 23 is provided on the inner peripheral portion of the mounting surface 22. ing. The center hole 74 of the flat face plate portion 73 provided on the rotor frame 71 of the motor 7 is fitted into the ring-shaped ridge 23 so that the rotor frame 71 and the rotary drum 2 are aligned. At the same time, the face plate portion 73 is overlaid on the mounting surface 22. The thrust bearing 52 is formed in a disk shape, the center of which is slidably superimposed on the receiving surface 31 formed by the upper end surface of the support shaft 3, and the outer periphery of the thrust bearing 52 is formed of the face plate 73. It is superimposed on the upper surface of the inner peripheral part. Further, on the upper surface of the thrust bearing 52, an annular electrode plate 91 as an earth electrode is provided so as to overlap. The rotary drum 2 is provided with a mounting screw 64 inserted through a screw insertion hole 63 formed through an overlapping portion between the face plate portion 73 of the rotor frame 71, the outer peripheral portion of the thrust bearing 52, and the electrode plate 91. It is screwed into the screw hole 24 and tightened. As shown in FIG. 2, in the illustrated example, the above-mentioned overlapping portions are fixed to the rotating drum 2 via mounting screws 64 at two locations separated by 180 degrees.

The rotary drum 2 is a die-cast molded body made of an aluminum alloy and having excellent dimensional accuracy, and the unprocessed ground surface of the molded body is used as the mounting surface 22 as it is.

In the above embodiment, both the face plate portion 73 of the rotor frame 71 and the outer peripheral portion of the thrust bearing 52 are screwed to the single flat mounting surface 22 formed on the upper surface of the rotating drum 2. Therefore, the mounting surface 22 serves as a reference surface for determining the parallelism of both the face plate 73 of the rotor frame 71 and the thrust bearing 52. As a result, the parallelism between the face plate portion 73 of the rotor frame 71 and the thrust bearing 52 is maintained even though the unprocessed ground surface of the die-cast molded body is used as the mounting surface 22 of the rotary drum 2 as it is. It is determined with a high degree of accuracy, so that vibration and rotation unevenness of the rotating drum 2 do not occur. For this reason, it is not always necessary to finish the upper surface of the rotary drum 2 with high precision. However, if necessary, the mounting surface 22 can be formed by cutting and finishing the upper surface of the rotary drum 2. In this case, since only one processing portion is provided, as shown in FIG. As compared with the case where both the inner peripheral side mounting surface 22a and the outer peripheral side mounting surface 22b are finished, the labor is greatly reduced. Further, when the mounting portions by the mounting screws 64 are set to two locations as shown in FIG. 2, the three components of the rotor frame 71, the thrust bearing 52, and the electrode plate 91 can be assembled with only the two mounting screws 64. The required number of mounting screws is greatly reduced as compared with a case where these three parts are assembled using individual mounting screws. Therefore, the necessity of performing the above-mentioned finishing processing is not necessarily eliminated, and the required number of mounting screws is reduced, thereby significantly reducing the manufacturing cost.

In the rotary magnetic head device according to the embodiment shown in FIGS. 1 to 3, other items are the same as those described with reference to FIGS. That is, the lower end of the support shaft 3 is fixed to the fixed drum 1 having the lead groove 11 for guiding the tape, and the radial bearing 51 is press-fitted at two positions above and below the through hole 21 of the rotary drum 2. Are fitted to the support shaft 3. Further, a stator 72 of the motor 7 is mounted on an upper plate portion 81 of the support 8 which is mounted on the fixed drum 1 and extends above the rotary drum 2, and the stator 72 has the rotor frame 71 described above. 74, and a pressing pin 82 is attached to the upper plate portion 81. The pressing pin 82 presses the thrust bearing 52 by the urging of the spring body 83 to press the support shaft 3 in the axial direction. . Further, a brush electrode 85 is attached to the upper plate portion 81, and the brush electrode 85 is urged by a spring body 86 to elastically contact the electrode plate 91. Then, the rotating drum 2 is electrically connected to a chassis (not shown) via the rotor frame 71, the mounting screw 64, the electrode plate 91, the brush electrode 85, the spring body 86, the support body 8, the fixed drum 1, and the like. As a result, the rotary drum 2 is grounded.

[0022]

[Effect of the invention]

 As described above, according to the present invention, when the motor is arranged above the rotating drum and both the thrust bearing and the rotor frame of the motor are mounted on the upper surface of the rotating drum with screws, the rotating drum is used. The thrust bearing and the face plate of the rotor frame of the motor are mounted on the basis of a single mounting surface formed on the upper surface of the motor, so the rotor frame and the thrust bearing can be mounted without finishing the mounting surface with high precision. Can be attached to the rotating drum while maintaining high parallelism. Therefore, when the rotating drum is a die-cast molded body with excellent dimensional accuracy, the upper surface of the rotating drum is used as a mounting surface without finishing the ground surface of the rotating drum and the thrust bearing is not used. Can be determined with high precision, which helps to improve image stability and image quality.

Further, according to the present invention, the rotor frame, the thrust bearing, and the electrode plate as the ground electrode are mounted on the rotating drum using the common mounting screws, so that the required number of mounting screws is required. This has the effect of reducing the number of parts by reducing the number of components.

[Brief description of the drawings]

FIG. 1 is a schematic longitudinal sectional view showing an embodiment of a rotary magnetic head device according to an embodiment of the present invention.

FIG. 2 is a plan view of the main part.

FIG. 3 is an enlarged longitudinal sectional side view of the main part.

FIG. 4 is a schematic longitudinal sectional view showing an embodiment of a rotary magnetic head device as a comparative example.

FIG. 5 is a plan view of the main part.

FIG. 6 is an enlarged vertical sectional side view of the relevant part.

[Explanation of symbols]

 Reference Signs List 2 rotating drum 3 support shaft 4 magnetic head 7 motor 22 mounting surface 51 radial bearing 52 thrust bearing 61, 62 mounting screw 64 mounting screw 71 rotor frame 73 face plate portion 85 brush electrode 91 electrode plate

Claims (4)

[Utility model registration claims] 1. A rotating drum having a magnetic head rotatably supported on a support shaft via a radial bearing, a thrust bearing for pressurizing the support shaft in the axial direction, and a motor rotor frame provided with separate mounting screws. In the rotating magnetic head device, the outer peripheral portion of the thrust bearing is overlapped on the upper surface of the inner peripheral portion of the face plate portion of the rotor frame, and the ground electrode on which the brush electrode slides on the upper surface of the thrust bearing. Each of the mounting screws that screw the thrust bearing and the rotor frame of the motor to the rotating drum together with the electrode plate as a stack, and the face plate portion of the rotor frame and the outer peripheral portion of the thrust bearing The overlapping portion with the electrode plate is replaced by a mounting screw screwed to a flat mounting surface formed by the upper surface of the rotary drum. The rotating drum is a metal die-cast molded body, and the mounting surface where the inner peripheral portion of the face plate portion of the rotor frame overlaps is an unprocessed ground surface provided in the molded body. A rotating magnetic head device. 2. A rotating drum having a magnetic head rotatably supported on a support shaft via a radial bearing, a thrust bearing for pressurizing the support shaft in the axial direction and a motor rotor frame each provided with separate mounting screws. In the rotary magnetic head device, the face plate portion of the rotor frame and the outer peripheral portion of the thrust bearing are overlapped, and the thrust bearing and the rotor frame of the motor are screwed to the rotating drum. Another mounting screw for fixing an overlapping portion between the inner peripheral portion of the face plate portion of the rotor frame and the outer peripheral portion of the thrust bearing to a flat mounting surface formed by the upper surface of the rotary drum. A rotary magnetic head device characterized by being replaced by: 3. The rotary magnetic head device according to claim 2, wherein a face plate portion of the rotor frame is overlapped on the mounting surface, and an outer peripheral portion of the thrust bearing is overlapped on an upper surface of the face plate portion. 4. An electrode plate as an earth electrode on which a brush electrode slides is superimposed on an upper surface of the thrust bearing, and the electrode plate is provided between an inner peripheral portion of the rotor frame and an outer peripheral portion of the thrust bearing. 4. The rotary magnetic head device according to claim 3, wherein an overlapping portion is screwed to a thrust bearing by the mounting screw screwing the upper surface of the rotary drum.