JPS6138386Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a frequency generator attached to a motor used in a constant speed tape drive device, for example, for controlling a capstan shaft to rotate at a constant speed.

In particular, the present invention rotates a rotor having a plurality of teeth on its inner circumferential surface, and rotates the rotor together with a capstan shaft, while each having a rotor on its outer periphery with an uneven surface having the same number of teeth as the rotor's uneven surface. For power generation, it is formed from two disk stator parts, an annular permanent magnet part interposed between both stators, and a power generation coil wound around the bobbin part on the outer periphery, and has a through hole bored in the center of the shaft. This invention relates to an improvement in a frequency generator mechanism configured with a fixed stator.

2. Description of the Related Art Conventionally, there is a DC motor having a structure as shown in FIG. 1, which has been used as a constant speed tape drive device. That is, a rotor F made of a high magnetic permeability material is fixed to a capstan shaft E which is rotatably supported by a bearing B provided on the upper substrate A and a thrust bearing D provided at the center of the driving stator C. has been done. The rotor F, that is, the capstan shaft E, has an annular permanent magnet G magnetized in the vertical direction attached to the lower surface of the rotor F, and a permanent magnet G on the drive stator C. The motor is rotated in a predetermined direction by a plurality of stator coils H arranged in positions opposite to the motor according to the number of phases of the motor.

On the other hand, an uneven portion having a plurality of teeth is formed on the inner circumferential surface of the rotor F, and an uneven portion J having the same number of teeth as the above uneven portion is formed on the bearing B extending below the upper substrate A. A power generation stator N consisting of two disc-shaped stators K ₁ and K ₂ made of magnetic material on the outer periphery, an annular permanent magnet L magnetized in the vertical direction, and a power generation coil M is fixed. The uneven portion of the rotor F and the power generation stator N constitute a frequency generator. As the rotor F rotates, the amount of magnetic flux from the permanent magnet L changes as the reluctance changes, so a signal with a frequency proportional to the rotation speed of the rotor F is generated in the generator coil M.
By configuring the speed feedback system so that the frequency of the signal obtained from the generator coil M is constant based on this signal, the capstan shaft F can be rotated at a constant speed.

However, the power generation stator N in the conventional frequency generator mentioned above is composed of two disc-shaped stators K ₁ ,
Since it is constructed by assembling the stator K ₂ , the permanent magnet L, and the power generating coil M, the number of parts is large, and the assembly process, especially the two disc-shaped stators K ₁ and K ₂ , are Irregularities J formed on the outer periphery
Since the components are assembled by matching the phases of the components, skill is required for assembly, and it is difficult to make the precision uniform.

In order to solve the above-mentioned drawbacks, this invention
It is an object of the present invention to provide a power generation stator in a frequency generator attached to an electric motor, which is integrally molded from a moldable and magnetizable material.

The present invention will be described in detail with reference to an illustrated embodiment. In FIG. 2, 1 is a capstan shaft, and this capstan shaft 1, like a general-purpose one, runs a magnetic tape (not shown) in a predetermined direction by pinching it with a pinch roller. It is something that makes you The above capstan shaft 1 is mounted on a bearing 4 provided on the upper board 3 of the motor housing 2.
It is rotatably supported by a thrust bearing 6 provided on the lower substrate 5.

Reference numeral 7 denotes a rotor formed in the shape of a cylinder with a bottom and made of a high magnetic permeability material, and the rotor 7 is fixed to the capstan shaft 1 with the bottom part 8 facing upward. and,
An uneven portion 9 having a plurality of teeth is formed on the inner peripheral surface of the rotor 7 .

Reference numeral 10 denotes a power generation stator which constitutes a frequency generator together with the above-described uneven portion 9, and is fixed to the lower substrate 5 and disposed within the rotor 7. This power generation stator 10 includes two upper and lower disk stator parts 12a, 12b each having the same number of uneven parts 11 as the number of teeth of the uneven parts 9 of the rotor 7 on the outer periphery, and both stator parts 12a, 12.
It consists of an annular permanent magnet part 13 interposed between b and a bobbin part 15 for winding a power generating coil 14 formed by both disc stator parts 12a, 12b and the permanent magnet part 13. Stator 1 for power generation above
0, the disc stator parts 12a, 12b, the permanent magnet part 13, and the bobbin part 15 are formed by integral molding using a moldable and magnetizable material such as a rubber magnet material or a plastic magnet material. Thereafter, multipole magnetic pole surfaces are formed on the upper and lower sides of the power generation stator 10, and the power generation coil 14 is wound around this bobbin portion 15.

The operation of the power generation stator 10 and the rotor 7 is similar to that of the conventional example described above.
A frequency generator is constituted by a signal flowing from the disk stator 12a to the generating coil 14 via the uneven portion 9 formed on the inner peripheral surface of the rotor 7 and the disk stator 12b. Further, since the magnetic flux from the permanent magnet 13 fluctuates as the rotor 7 rotates, a signal having a frequency proportional to the rotation speed of the rotor 7 is generated in the generator coil 14. By configuring the speed feedback system so that the frequency of the signal obtained from the generator coil 14 is constant based on this signal, the capstan shaft 1 can be rotated at a constant speed.

Reference numeral 16 denotes an annular permanent magnet magnetized vertically with multiple poles, and is fixed to the upper surface of the bottomed portion 7a of the rotor 7.

Reference numeral 17 denotes a stator coil, and the coil 17 is located on the back surface of the upper substrate 3 and is connected to the permanent magnet 1.
The stator coils 17 and 6 are arranged in a number corresponding to the number of phases of the motor.
The capstan shaft 1 is rotated in a predetermined direction by the permanent magnet 16 described above.

As described above, the present invention includes two large diameter disc stator parts 12a and 12b, upper and lower, each having a concave and convex portion 11 on the outer periphery of a power generation stator 10, and a structure that is sandwiched between the two disc stator parts 12a and 12b. After the small-diameter annular permanent magnet part 13 and the bobbin part 15 for winding the power generating coil 14 are integrally molded from a moldable and magnetizable material, the power generating coil 14 is wound around the bobbin part 15. At the same time, multipole magnetic pole surfaces are formed on the upper and lower sides of the power generation stator 10, and the power generation stator 10 is fixed on the lower substrate 5 in the inner part of the rotor 7.

Therefore, the number of parts can be reduced, and the process of assembling the power generation stator 10 is completely unnecessary.
In particular, if the phases of the concave and convex portions 11 of the upper and lower disc stator portions 12a and 12b are designed at the time of molding, it is possible to obtain completely phased components.
Highly accurate products can be mass-produced, and manufacturing costs can be reduced due to the above advantages.

[Brief explanation of the drawing]

Fig. 1 is a cutaway perspective view of the main parts of a motor used in a conventional tape constant speed drive device, and Fig. 2 is a part of a motor used in a tape constant speed drive device equipped with a frequency generator according to the present invention. Perspective cutaway view, 3rd
The figure shows a cross-sectional plan view of the device. 1... Capstan shaft, 7... Rotor, 9...
Uneven part, 10... Stator for power generation, 11... Uneven part, 12a, 12b... Disc stator part, 13...
...Permanent magnet section, 14...Generating coil, 15...Bobbin section.

Claims (1)

[Scope of utility model registration request] A rotor, which is fixed to a capstan shaft and rotates in a predetermined direction and has an uneven portion with a plurality of teeth on its inner circumferential surface, is provided in a motor housing consisting of an upper substrate and a lower substrate. 2, each having an uneven part on the outer periphery with the same number of teeth as the uneven part formed on the surface.
A power generation stator that is formed from a disc stator part, an annular permanent magnet part interposed between both stators, and a power generation coil wound around a bobbin part on the outer periphery of the permanent magnet part, and has a through hole bored at the center of the shaft. is fixed to a lower substrate of the housing, passes through a through hole formed in the stator, and rotatably supports a capstan shaft by an upper substrate and a lower substrate of the motor housing. After the large-diameter disc stator portion, the small-diameter permanent magnet portion, and the bobbin portion of the power generation stator are integrally molded from a moldable and magnetizable material, a power generation coil is wound around the bobbin portion. At the same time, multi-pole magnetized magnetic pole surfaces are formed on the top and bottom of the power generation stator,
A frequency generator mechanism for an electric motor, characterized in that the power generation stator is fixed on a lower substrate in an inner part of a rotor.