JPS5931121B2 - turntable device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a support device for a turntable, in which a gap formed between a turntable and a turntable frame is filled with a magnetic fluid, and the turntable, turntable frame, and magnetic The present invention relates to a turntable device in which air pressure that maintains pressure equilibrium with external atmospheric pressure is sealed in an internal space surrounded by fluid.

Conventionally, an air floating turntable has been put into practical use as a support device for a turntable.

However, with the Airflow Young type, air is constantly flowing into the gap between the turntable and the turntable frame, so the sound of air being blown out and the mechanical sound of the air pump become noise and interfere with the acoustic effect. was. Further, there are drawbacks such as the need for expensive equipment such as an air pump, and the limited storage space that makes it impossible to reduce the size and weight of the device. This invention was made to improve the above-mentioned conventional drawbacks, and the turntable support device is installed across the gap formed between the turntable and the turntable frame so that the turntable axis and the central axis are the same. A magnetic field having an annular shape is formed in at least one place, and the gap where this magnetic flux exists is filled with a colloidal magnetic fluid formed by suspending fine powder of a magnetic substance in water, an organic solvent, etc., sealing the internal space surrounded by the turntable, turntable frame, and magnetic fluid;
The present invention provides a turntable device configured to support a return table through pressure equilibrium between external atmospheric pressure, internal space air pressure, and the weight of the turntable.

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

1 and 2 are diagrams explaining the principle according to the present invention, in which 1 is a turntable, 2 is a turntable frame, 3 is a rotating shaft, and 4 is a magnetic fluid; the turntable 1 and the turntable frame 2. There are multiple locations installed concentrically within the space between the two. A magnetic pole 5 is provided on the turntable frame 2 on which the magnetic fluid 4 is installed. Therefore, by applying a magnetic field to the magnetic poles, the air gap is sealed, and furthermore, it becomes possible to shut off the gap with zero friction. Therefore, due to this effect, an isolated internal space is formed between the return table 1, the turntable frame 2, and the magnetic fluid 4. As is already known, the magnetic fluid 4 has magnetic particles stably suspended in a colloidal manner in a carrier liquid, and is ultra-stable.

Therefore, since the solid magnetic particles do not separate from the carrier liquid of the base liquid, they can be controlled remotely by the magnet at the required location and time, ensuring completely leak-free sealing, high-speed rotation, and friction. Produces advantages such as low seals, dustproof seals, and self-lubricating bearings. FIGS. 3 and 4 are sectional views of main parts of a turntable device using the above-described principle, with and without a rotating shaft, respectively.

In the figure, 1 is a turntable, 2 is a turntable frame, 3 is a rotating shaft, 4 is a magnetic fluid, 5 is a magnetic pole of a magnet, etc., 6 is a yoke, and 7 is a drive section. At a predetermined position where the turntable frame 2 faces the lower surface of the turntable 1, a chamber 18 for floating the turntable 1 is formed in the shape of an annular groove, and this chamber 18 is adjusted via a conduit 9. It is connected to the container 10. The above regulator 10 includes a turntable 1, a turntable frame 2
and magnetic fluid 4 to maintain an internal gap 11 at a predetermined pressure. Further, the regulator 10 is composed of a cylinder 10a, a piston 10b, and a valve 10c.
The pressure inside 1 can be adjusted. The operation of the turntable device configured as described above will be explained.

First, the valve 10c of the cylinder 10a is opened, and the piston 10b is inserted to an appropriate position and set to be slidable. Then, close the valve 10c and move the piston 10b. The air inside the cylinder 10a is sent into the chamber 18. Therefore, the external pressure, the pressure due to the weight of the turntable 1, and the pressure within the internal cavity 11 communicating with the sealed chamber 18 are maintained in a balanced state. Therefore, when current is passed through the drive section 7, the turntable 1 rotates in an air floating state. The regulator 10, which maintains the pressure in the internal cavity 11 constant via the chamber 8, is operated not only when the turntable 1 is installed;
In response to changes in atmospheric pressure and ambient temperature, internal voids 11
Since the internal volume changes, the adjuster 10 is used for fine adjustment, and only needs to be adjusted so that the balance position does not deviate much from a predetermined set position. Therefore, the amount of fine adjustment due to changes in atmospheric pressure and temperature is extremely small, and the adjuster 10 is not used frequently, and adjustment before the start of playing a record or the like is sufficient. In addition, the regulator 1
Fine adjustment of 0 can also be automated. In the above configuration, the magnetic fluid 4 installed in the gap between the turntable 1 and the turntable frame 2 is directed toward the turntable 1 via the magnetic pole 5 and yoke 6 embedded in the turntable frame 2 in an annular shape. Magnetic flux is coming out.

As explained in detail above, the turntable device according to the present invention is an air floating type using magnetic fluid, and vibrations from the cabinet are not directly transmitted to the turntable, allowing stable support of the turntable. It is. Further, by designing the magnetic fluid and adjuster in an optimal state depending on the shape of the turntable, the arrangement of magnetic poles, the weight of the turntable, etc., it is possible to obtain a turntable support structure that eliminates the central bearing.

Note that even when a center bearing is used in combination, a bearing structure for thrust loads is not required, and vertical vibrations around the turntable caused by the machining accuracy of the bearings are eliminated. Furthermore, since the turntable is supported by pressure equilibrium instead of by the fulcrum of the center bearing, the presence of the fulcrum eliminates the vertical vibrations around the turntable caused by the swerving motion of the rotating body, which was conventionally unavoidable. Furthermore, when a center bearing is used together, the weight of the shaft rather than the bearing has the effect of stabilizing the turntable, and it functions as a stabilizer.

For this reason as well, it is desirable to have a space below the central axis to avoid receiving any drag from the frame.

[Brief explanation of drawings]

FIGS. 1 and 2 are explanatory diagrams showing the principle of the present invention, and FIGS. 3 and 4 are sectional views of essential parts of a turntable device showing an embodiment of the present invention. 1... Turntable, 2... Turntable frame, 3... Rotating shaft, 4...
...Magnetic fluid, 5...Magnetic pole, 8...Chamber 1, 10...Adjuster, 11...
internal space.

Claims (1)

[Claims] 1. In a support device for a turntable, a magnetic field is formed in at least one place that crosses the air source formed between the turntable and the turntable frame and has an annular shape with the turntable axis and the center axis, and this magnetic flux is The existing void is filled with a magnetic fluid made by colloidally suspending fine powder of a magnetic substance in a predetermined carrier solution, and the internal space surrounded by the turntable, turntable frame, and magnetic fluid is sealed off and the outside is sealed off. A turntable device characterized by maintaining atmospheric pressure and air pressure in an internal space in an equilibrium state.