JPS6125069Y2 - - Google Patents

Description

[Detailed explanation of the invention] This invention is a video tape recorder (hereinafter referred to as VTR).
The present invention relates to a rotary magnetic head drive device in which a rotary magnetic head drive shaft (referred to as ``1'') is directly driven by a coreless cup motor.

Many of the cassette-type VTRs currently on the market are of the stationary type, and it would have been more convenient to use a commercial power source and use an AC motor as the drive means. but,
If a cassette-type VTR is small and lightweight, it is desirable to be able to record outdoors using a video camera.As long as a VTR is used outdoors, the power supply must depend on a storage battery, and a DC motor is used as the drive means. It is more convenient to do so.

Therefore, the present invention uses a coreless cup motor, which is suitable for being integrated into the guide cylinder, among the DC motors that are convenient for use in small and lightweight VTRs, and contributes to simplifying assembly and adjustment and improving serviceability. It is an object of the present invention to provide a rotating magnetic head drive device.

The present invention will be described below with reference to an illustrative embodiment. The figure shows a partial central sectional view of the rotary magnetic head drive device of this embodiment. The feature of this embodiment is that the cylindrical portion below the lower guide cylinder is integrally molded concentrically with the circumferential surface of the lower guide cylinder.
By fitting and fixing the stator magnet, the stator magnet can be fixed concentrically to the rotary magnetic head drive shaft without adjustment, and the rotary magnetic head drive shaft can be fixed to the cylindrical portion of the lower guide cylinder. The rotor is adjusted and fixed to the bearings on both sides and then removably screwed and fixed to the lower part of the drive shaft, thereby making it easy to install and remove the rotor, which has a relatively high failure rate. Below, each component will be explained according to the drawing number. First, figure number 1 is the upper guide cylinder that guides the magnetic tape around the outer periphery.
Reference numeral 2 denotes a lower guide cylinder which is fixed oppositely to the upper guide cylinder 1 with a small gap by a connector (not shown) and guides the magnetic head together with the upper guide cylinder 1, and has a cylindrical portion 2a extending downward. is integrally machined with high precision concentrically with the magnetic head guide surface. Next, numerals 3 and 3 indicate a rotating magnetic head that protrudes slightly outward from the gap between the guide cylinders 1 and 2 and rotates to scan the magnetic head surface for recording and playback; 4 indicates the magnetic head 3, 3;
6, 6 is a rotor of a rotary transformer fixed to the disk 4, and 7, 7 is a support member 8 fixed to the lower guide cylinder 2. Stators 6, 6 of the rotary transformer facing the fitted rotors 6, 6 and stator magnets 9 of the rotary transformer having the rotary disk 4 fixed thereto, and magnets 9 on both upper and lower sides of the cylindrical portion 2a. A rotary magnetic head drive shaft supported by fitting bearings 10, 10, 11 a cylindrical stator magnet fitted and fixed to the outer periphery of the cylindrical portion 2a, 12 a cylindrical stator magnet attached to the lower part of the rotary magnetic head drive shaft 9; The fixed rotor mounting plate 13 is fixed to the outer periphery of the mounting plate 12, and the cut rotor 14 faces the outer periphery of the stator magnet 11. tube,
15 is a bottom plate that covers the lower side of the outer cylinder 14; 16 is fixed to the upper surface of the bottom plate 15, and is attached to the rotor mounting plate 1;
2 shows brushes that come into sliding contact with a commutator 12a formed on the lower surface. The remaining figure number 17 is a nut that clamps and fixes the rotary disk 4 together with the inner ring of the lower bearing 10, and 18 is a nut that fixes the support member 8 to the lower guide cylinder 2 and the upper nut that holds the support member 8. 1 a bolt for securing the outer ring of the bearing 10; 19 a nut for holding the rotor mounting plate 12 together with the inner ring of the lower second bearing 10; 2;
Reference numeral 0 indicates an adjustment nut that is screwed into the cylindrical portion 2a and supports the outer ring of the second bearing 10 in a vertically adjustable manner, and 21 indicates a fixing screw that fixes the bottom plate 15 to the outer cylinder 14, respectively.

When assembling the device of this embodiment, first the bearing 1
0 and 10, the rotating magnetic head drive shaft 9 is inserted into the cylindrical portion 2a, and the outer ring of the second bearing 10 is opposed to the support member 8 to which the outer ring of the first bearing 10 is screwed and fixed. By opposing the adjusting nut 20, the rotating magnetic head drive shaft 9 is held in the cylindrical portion 2a so as not to come out. Next, after fixing the rotating disk 4 on which the rotating magnetic heads 3, 3, etc. are arranged and fixed to the upper part of the rotating magnetic head drive shaft 9 with the nut 17, the upper guide cylinder 1 is fixed, The rotor mounting plate 12 is tightened and fixed to the lower part of the rotating magnetic head drive shaft 9 with the nut 19, and the cutout rotor is mounted concentrically with the outer periphery of the stator magnet 11, which is fitted and fixed to the outer periphery of the cylindrical body 2a. I support 13. Thereafter, in order to re-fix the rotating magnetic head drive shaft 9 without play, the adjustment nut 20 is tightened through the through hole 12b of the rotor mounting plate 12, and the first
The rotating magnetic head drive shaft 9 is firmly held by the inner rings of the second bearings 10, 10. Furthermore, the integral brush 16 is fixed to the bottom surface of the outer cylinder 14 which is fitted and fixed to the step part 2b, and the bottom plate 15 is tightened and fixed with the fixing screws 21, so that the commutator 19... The brush 16 is brought into elastic contact.

When inspecting and repairing the device of this embodiment assembled in the order described above, first the fixing screw 21
If you loosen the bottom plate 15 and remove the brush 16
Furthermore, when inspecting and replacing the rotor cup 13, by loosening and removing the nut 19, the rotor cup 13 can be removed together with the rotor mounting plate 12 without moving the rotating magnetic head drive shaft 9. Can be done. Furthermore, if play occurs in the rotating magnetic head drive shaft 9, the through hole 12 can be removed without removing the rotor mounting plate 12.
The adjusting nut 20 can be tightened via b.

Therefore, according to the apparatus of this embodiment, the rotary magnetic head drive shaft and the stator magnet are manufactured at a high height in order to manufacture the cylindrical portion that supports the rotary magnetic head drive shaft and the stator magnet integrally with the lower guide cylinder with high precision. Can be supported concentrically with precision. Furthermore, as described above, in this embodiment of the apparatus, the cutter rotor can be replaced without moving the rotary magnetic head drive shaft during service inspection, and adjustment work during service inspection can be eliminated.

[Brief explanation of the drawing]

The figure shows a partial central sectional view of an embodiment of the present invention. Explanation of main drawing numbers, 2...lower guide cylinder,
2b...Cylinder part, 11...Stator magnet, 9
...Rotating magnetic head drive shaft, 13...Cut rotor, 12...Rotor mounting plate.

Claims (1)

[Scope of utility model registration request] A cylindrical portion integrally formed with the lower guide cylinder, a stator magnet fitted to the outer periphery of the cylindrical portion, and a rotating magnetic head drive shaft supported and fixed concentrically within the cylindrical portion by a bearing. . A rotary magnetic head drive device comprising: a rotor mounting plate fixed to a lower portion of the rotary magnetic head drive shaft for supporting the rotor rotor concentrically and facing the stator magnet.