JPS62285805A - Floating support mechanism and starting method therefor - Google Patents

Abstract

PURPOSE:To facilitate start of rotation of a rotating disc member and to assure generation of dynamic pressure by providing a main foating device including a rotating disc member mounted on the extreme end of a driving shaft and having a surface formed with grooves for generating dynamic pressure, and a leg member disposed around the main floating device and incorporating therein a piezoelectric element which changes its length when voltage is applied thereto. CONSTITUTION:Power is supplied to a main floating device 20 and, at the same time, voltage is applied to a piezoelectric element 15 in a leg member 11 disposed around the main floating device 20 to lift a disc member 31 of the main floating device 20 above a floor surface 41. After a motor 21 of the main floating device 20 reaches a rated speed, fluid such as air is introduced by grooves formed in the lower surface 32 of the disc member 31 toward the center of the disc member 31. This generates dynamic pressure between the disc member 31 and the floor surface 41, and as the disc member 31 is floated above the floor surface 41, the voltage applied to the piezoelectric element 15 becomes gradually lowered to gradually reduce the length of the piezoelectric element 15. Thus constructed, with no contamination of the clean-room environment, the disc member 31 of the main floating device 20 can be easily floated above the floor surface 41, permitting easy start of rotation of the disc member 31 and assuring generation of dynamic pressure.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Industry-4 Second Field of Application] The present invention relates to a floating support mechanism suitable for use in a clean environment. A ceramic plate is rotated, and an object or thrust cargo is supported by a fluid film created by this spiral groove.
``!Relating to a support mechanism and its starting method.

[Prior Art] Conventionally, goods have been handled in a clean environment in semiconductor manufacturing, bioindustry, pharmaceutical manufacturing, and the like.

As an article moving device in such an environment, it is necessary to smoothly move articles and slide the moving table! In order to avoid the generation of dust due to wear of the 0 part, an air slider is used that blows out high-pressure air from an air nozzle installed on the floor to raise and move the floating platform above the floor. However, the air slider had the disadvantage of requiring a large amount of high-pressure air.

For this reason, by rotating the disc provided under the floating table, dynamic pressure is generated between the disc and the floor surface, and the floating support 4 floats the disc from the floor surface! ! A structure has been proposed.

The main floating device of the floating support mechanism is composed of a driving motor and a disk portion having a spiral groove formed on the lower surface,
As shown in FIG. 4, a motor 21 is provided within the casing 19, and a disk portion 31 is provided at the lower end of the drive shaft 22 of the motor 21.

The disk portion 31 has a lower surface 32 facing the floor 41 formed with a ceramic layer 39 to increase its strength, and a number of spiral grooves 3B are formed around the lower surface 32 as shown in FIG. The center portion is a flat pressure equalizing portion 35. The depth of the groove portion 36 is about 3 to 20 gm, and the bottom of the groove portion 3B is formed at the same height as the pressure equalizing portion 35.

Therefore, when the disc part 31 is rotated at high speed on a smooth floor surface 41, fluid such as air is concentrated on the pressure equalizing part 35 due to the groove part 36, dynamic pressure is generated, and the disc part 31 is rotated on the floor surface. 4
1 to 7γL.

The gap created between this floor surface 41 and the disc part 31 is approximately 1 #
Even though the gap is extremely narrow with respect to Lm, this fluid layer can reduce the coefficient of friction against the floor surface 41 to approximately zero, allowing heavy objects to be moved smoothly and easily, and driving the motor 21. has various advantages such as requiring extremely small power.

Problems that E-14 attempts to solve] As mentioned above, a motor rotates a disc part with a spiral groove against the smooth east face, and the disc part is floated by dynamic pressure. Since the floating support mechanism supports a large object via a fluid layer with an air layer, it is possible to move the object easily and smoothly. Although a small amount of power is sufficient for this purpose, when starting the main floating device,
That is, when starting the rotation of the disc part, it is necessary to lift the disc part from the floor surface, and after the disc part, that is, the motor reaches the rated rotation speed, the disc part is gradually raised to the floor surface. Although it is possible to use an i+l+ EE cylinder, a cam, and a rond, it has the disadvantage of complicating the floating support mechanism.

[Means for Solving Opening and Closing] The present invention provides a floating support mechanism having a main floating device in which a groove for generating dynamic pressure is formed on the surface of a rotating disk portion provided at the end of a drive shaft. The lower end of the leg is located at a position slightly higher than the height of the lower surface of the disk of the main floating device, and a portion of each leg is constructed with a piezoelectric element. The method for starting the floating support mechanism is to interlock the power switch of the pressure element with the power switch of the motor, so that the piezoelectric elements arranged around the main floating device are activated to start the main floating device. This is a method for starting a floating support mechanism in which a predetermined voltage is applied at the same time, and the voltage applied to the piezoelectric element is cut off after a required period of time.

[Function] The floating support mechanism according to the present invention is provided with legs around the main floating device, the legs have a piezoelectric element, and the piezoelectric element has a
By adding Ichikawa, the length of the legs can be easily expanded and contracted, and the disc part of the main floating device can be easily lifted from the floor.

Furthermore, piezoelectric elements have a fast response speed to applied voltage,
By applying voltage to the piezoelectric element at the same time as the start of the main floating device, it is possible to instantly lift the disk part from the floor even if there is a small gap, and it is also linked with the power switch of the main floating device. This makes it easy to apply voltage to the piezoelectric element.

Additionally, the method of applying voltage to the piezoelectric element at the same time as starting the main floating device can be easily automated by linking the power switch of the main floating device and the '+l source switch of the piezoelectric element, and the switch for starting the floating support mechanism can be easily automated. It is easy to operate and lifts the disk part of the main floating device from the floor by applying voltage to the piezoelectric element at the same time as starting the main floating device, ensuring that the disk starts rotating. ,and,
Since this method cuts off the voltage applied to the piezoelectric element after the required time, the piezoelectric element is compressed after the motor and disk reach the required rotation speed, and the dynamic pressure generated by the rotation of the disk causes the floor to This is a method of starting a floating support mechanism that can easily achieve support by a main floating device that has extremely low frictional resistance with a surface.

[Embodiment] As shown in FIG. 1, an embodiment of the present invention is a floating device having two main floating devices 20 each having a disk portion 31 at the lower end of a drive shaft 22 of a motor 21 built into a casing 19. This is a support mechanism 10.

The two floating support mechanisms 10 have the same structure, and by rotating the disk portion 31 in opposite directions, the reaction force generated in the floating support mechanism 10 is canceled out.

The disk portion 31 has a ceramic layer 33 on the upper surface 33 and lower surface 32 to increase its strength, so that even when dynamic pressure is generated, the degree of deformation of the upper surface 33 and the lower surface 32 is reduced. As shown in FIG. 2, a spiral groove 36 for generating dynamic pressure is carved around the lower surface 32 of the disc part 31, and a spiral groove 36 is similarly formed on the upper surface 33. ing. It goes without saying that the surface of the pressure equalizing section 35, which is formed at the same height as the surface of the disk section 31, the bottom surface of the groove section 3B, and the bottom surface of the groove section 36, is an extremely smooth flat surface. .

Furthermore, an elastic plate 2 made of silicone rubber is provided above the disc part 31.
6, the bearing plate 25 whose lower surface is made of a ceramic layer 27 and whose surface is extremely smooth is a disk? It is attached to the casing 19 so as to be close to A31.

In addition, the casing 1 surrounds the two main floating devices 20.
Near the four corners of 9, as shown in FIG. 3, there are struts 13 fixed to the leg base 12 screwed to the casing 19 with extremely short pitch screws, and having a piezoelectric element 15 at the lower end. By attaching it, a leg portion 11 is formed. The height of the lower end 17 of the leg portion 11 is approximately +pmJ higher than the lower surface 32 of the disk of the main floating device 20. It is adjusted so that it is at a position one degree higher.

This is because an element called a laminated piezoelectric actuator is used as the piezoelectric element 15, and when a voltage is applied to the piezoelectric element 15, the amount of elongation displacement is several + pm, and the elongation of the piezoelectric element 15 causes the legs to The lower end 17 of the leg can slightly lift the disc part 31 from the floor surface 41 when the length of the leg 11 is extended.
The height can be adjusted.

When starting the floating support mechanism 10 having the main floating device 20 and the legs 11 as described above, a voltage is applied to the piezoelectric element 15 at the same time as the motor 21 is turned on, thereby causing the piezoelectric element 15 to expand. The disk portion 31 is lifted from the floor surface 41. Applying a voltage to the piezoelectric element 15 at the same time as the power to the motor 21 is turned on can be achieved by interlocking the power switch of the piezoelectric element 15 and the power switch of the motor 21.

Furthermore, an auxiliary switch is provided in series with the power switch of the piezoelectric element 15, and the auxiliary switch is normally ON97g.
The rotation speed of the motor 21 of the main floating device 7120 is detected, and when the rotation speed of the motor 21 reaches the rated rotation speed, the O
This is a governor switch that is in the FF state.

Therefore, by turning on the power of the motor 21, the power switch of the piezoelectric element 15 is turned on and the piezoelectric element 15 is expanded, and the disk part 31 is lifted from the floor surface 41 by -E.
The first rotation of the motor 21 can be performed by pressing the disc part 3.
1 starts rotating without solid contact, and fluid such as air is sent into the center of the disc part 31 through the groove part 36 formed on the lower surface 32 of the disc part 31, thereby causing the disc part 31 and the floor surface 41 to
Dynamic pressure will be generated between the two. At this time, the disk portion 31 also generates dynamic pressure between the bearing plate 25 and the disk portion 31 due to the groove portion of the surface 33 thereof.

Then, when the required time has elapsed since the power of the motor 21 was turned on and the motor 21 reaches the rated rotation, the auxiliary switch turns OFF, and the voltage applied to the piezoelectric element 15 becomes zero, so that the piezoelectric element 15 is shortened to its initial length, and thus the disc portion 31 and the casing 19 descend.

However, dynamic pressure is generated between the disc part 31 and the floor surface 41 due to the high speed rotation of the disc part 31.
A casing layer of about 1 m is formed between the casing layer 1 and the casing layer 1 to maintain a floating state above the floor surface 41.

Note that the groove provided on the upper surface of the disk portion 31
Dynamic pressure is generated between the bearing plate 25 and the bearing plate 25, and thereby the load l due to the cargo placed on the upper part of the casing 19 is transferred to the bearing plate 2.
5 and the fluid layer to the disk portion 31, thereby reducing the load applied to the bearing of the drive shaft 22.

Further, the auxiliary switch inserted in series with the power switch of the piezoelectric element 15 is not limited to the governor switch, and may be one that can electrically detect the rotation speed of the motor 21, in short, when the motor 21 reaches its rated rotation. In some cases, it is sufficient to use a switch that can turn the motor 21 into the OFF state.Furthermore, the motor 21 may be turned OFF after several seconds have passed after the power switch of the motor 21 is turned ON without detecting the rotation speed of the motor 21. be.

In this way, when turning off the auxiliary switch after the time required for the motor 21 to reach its rated rotation, various timer circuits and semiconductor switches such as monostable multivibrators and other circuits that utilize the discharge characteristics of capacitors can be used. Semiconductor switches are easy to assemble, and also have the advantage of maintaining a clean environment without generating sparks or other discharges when cutting off or connecting current.

Incidentally, the above embodiment uses two main floating devices 20 and one leg section II.
are provided at the four corners, but the number of main floating devices 20 is not limited to two, and the number of legs 11 is not limited to four,
Furthermore, the piezoelectric element 15 constituting a part of the leg part 15 is not limited to the case where it is provided at the lower end of the pillar part 13;
It is sufficient if a part of the leg If is formed at an appropriate position such as in the middle.

In particular, since the leg portion 11 is used to lift the disc portion 31 from the floor surface 41 when the main floating device 20 is started, the bottom area of the leg portion 11 should be widened to provide stability.

It may be sufficient to provide only one leg 11 at the center of the lower part of the casing 19, that is, at the center of two or three main floating devices 20, or the number of legs 11 may be increased as appropriate depending on the withstand pressure of the piezoelectric element 15. Since the piezoelectric element 15 has extremely low power consumption, the voltage to be applied to the piezoelectric element 15 can be obtained by appropriately connecting a solar cell in series with a solar cell to obtain the required voltage. In addition to the fact that the power consumption is relatively small, a motive power source can be provided to the floating support mechanism 10 by using a shade provided with solar cells in the casing 19, and the mobility of the floating support mechanism 10 can be further enhanced.

In short, it is a floating support in which legs 11 incorporating piezoelectric elements 15 whose length changes only by applying a voltage are arranged around the main floating device 20 so that the disc part 31 can be lifted from the floor surface 41. At the same time as the power switch of the main floating device 20 is connected, a voltage is applied to the piezoelectric element 15 of the leg portion 11 provided around the main floating device 20, thereby causing the disk of the main floating device 20 to This method is for starting the floating support mechanism 10 by lifting the section 31 from the floor 41 and cutting off the voltage applied to the piezoelectric element 15 after the required time for the motor 21 of the main floating device 20 to reach its rated rotation. In addition, when cutting off the voltage applied to the piezoelectric element 15, if the voltage is gradually dropped from a predetermined voltage without reducing the voltage to zero all at once, the shortening of the piezoelectric element 15 will gradually occur as the voltage drops. Therefore, the disc portion 31 can be lowered gently.

[Effects of the Invention] Since the present invention is a floating support mechanism in which legs incorporating piezoelectric elements are provided around the main floating device, the manufacturing gap is +-14iJ.
v 1 song ΔIJ ti: We-jgeldiWOre
The disk part of the main floating device can be easily raised from the floor with a simple structure, and the rotation of the disk part can be easily started to generate dynamic pressure. can be ensured.

In addition, a method of interlocking the power switch of the piezoelectric element and the power switch of the motor to apply voltage to the piezoelectric element at the same time as the start of the main floating device and to cut off the voltage after the required time is to use a timer or motor rotation detector. This is a method that can be easily automated using the main floating device, and is a method that allows the disk portion of the main floating device to be raised from the floor for the time required for the disk portion to reach high speed rotation. can be started easily and reliably.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional side view of a floating support mechanism according to the present invention, and FIG.
The figure is a bottom view, the third figure is a figure showing the legs, and the fourth figure is a bottom view.
The figure is a cross-sectional side view of the main floating device, and FIG. 5 is a view showing the lower surface of the disc part. 10=floating support mechanism, 11: leg, 12=leg base, 13=pillar, 15=piezoelectric element, 17
= lower end of leg, 19 = casing, 20 = main floating device, 21 = motor, 22 = drive shaft, 25 = bearing plate, 26 = elastic plate, 27 = bearing plate ceramic layer,
31=Disk part, 32=Bottom surface of disk part, 33=Top surface of disk part, 35=Pressure equalization part, 3B=Groove part, 39=Ceramic layer of disk part, 41=Floor surface. Sai 4 Figure/Δ

Claims (3)

[Claims] (1) In a floating support mechanism having a main floating device in which a groove for generating dynamic pressure is formed on the surface of a rotating disk portion provided at the end of the drive shaft, legs are provided near the main floating device, The floating support mechanism is characterized in that the lower ends of the legs are located at a position slightly higher than the height of the lower surface of the disk of the main floating device, and each leg is partially constituted by a piezoelectric element. (2) In a floating support mechanism in which legs incorporating piezoelectric elements are arranged around the main floating device, the power switch of the piezoelectric element is linked with the power switch of the motor, so that the piezoelectric element is connected to the main floating device. A method for starting a floating support mechanism, characterized by applying a predetermined voltage at the same time as starting, and cutting off the voltage applied to a piezoelectric element after a required period of time. (3) A method for starting a floating support mechanism according to claim 2, characterized in that when cutting off the voltage applied to the piezoelectric element, the applied voltage is gradually lowered from a predetermined voltage to zero voltage.