JPS5938452B2 - Movable holding device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for holding a movable part without providing mechanical contacts, and more particularly to a movable holding device for holding a rotating movable part with extremely little friction by ejecting a medium.

Conventionally, there are subbase bearings and rolling bearings as mechanisms for holding rotating shafts, but these move relative to each other through a thin oil film, or the shaft and bearing move relative to each other through rolling elements.
Mechanical friction cannot be avoided. Therefore, it has disadvantages such as temperature rise, grinding, and shortened lifespan due to bearing fatigue.
It also had the serious drawback of loss of kinetic energy. Magnetic bearing devices have been devised to prevent these drawbacks, but many devices require complicated structures because it is difficult to maintain balance, and due to the nature of the material, they are heavy and demagnetize, making it difficult to magnetize. However, it also had disadvantages such as magnetic leakage.

The present invention is a holding device with extremely low mechanical friction that levitates a rotating part by the force of a jet of a medium such as gas or liquid obtained by its own rotation, and is lightweight, inexpensive, and highly durable. This device has various excellent features such as:

EMBODIMENT OF THE INVENTION The principle of this invention is demonstrated below, and it is demonstrated in detail according to an Example.

Generally, when a jet acts on a flat plate, the force F is F=
(to/g) Qυ (where r is the unit volume weight of the fluid, g is the acceleration of gravity,
Q is the flow rate and υ is the velocity.

), and when the flat plate is small or when members with various shapes are used instead of the flat plate, Fig. 1 A, b, c
As shown in , it is determined by the angle β between the direction 3 of the jet flow before collision and the direction 2 of the flow when leaving the member 1,
The jet velocity, flow rate, and unit volume weight of the fluid can be calculated based on the shape of the member, etc.

For example, if N2 gas is used and the flow rate is 1 m°/Sec and the flow velocity is 10 m/Sec, a force F of about 1.28 kg can be obtained.

Since the present invention rotates while being floated or supported by a medium such as gas or liquid, mechanical friction can be ignored.

Furthermore, the resistance can be improved by minimizing the viscous friction of the medium. For example, the viscosity η of a gas is (where M is the molecular weight, T is the absolute temperature, and σ is the diameter of the molecule)
Hail to you.

As understood from the above equation, the viscosity η of a gas with a larger molecular diameter and lower molecular weight decreases, making it possible to reduce viscous friction during rotation. In particular, it is understood that the diameter of the molecule greatly affects the viscosity. For example, at 20°C, helium 196 x 10-69/CTn-Sec, hydrogen 84 x 10-69/(11-Sec, ammonia 100
×10-69/?・Sec, butane 74×10-69/
Values such as CTL and Sec are determined. Therefore, it is understood that the unit volume weight of the fluid and the diameter of the molecules described above, which affect the force due to the jet described above, are greatly related to the jet force and rotational force of the present invention, and the holding device is You can choose the type of media depending on your purpose and content to get the best results.

Next, the basic configuration of the present invention will be explained.

Figure 2 shows the basic configuration diagram.

As the rotating part 5 rotates, a medium 10 made of gas or liquid is sucked by the medium absorbing mechanism part 8, passes through the medium guiding path 7, and is ejected from the medium spout 6 to the holding part 4. The ejection force at this time causes the rotating part to float, and the higher the rotational speed, the more the ejecting force increases, and the floating blades of the rotating part increase. The rotating part 5 and the opposing holding part 4 have a structure that prevents lateral displacement, and at the same time, the spout 6 also has various forms. Further, a non-contact bearing 9 is used to prevent displacement at a position different from that of the holding part.

This non-contact bearing can be one that utilizes the ejection force described above, or a magnetic bearing that utilizes magnetic counterforce. As understood from the above, the present invention obtains a floating blade through its own rotation, and constitutes a movable holding part with very little friction.

Next, specific examples of the present invention will be shown.

In the apparatus shown in FIG. 3, an electric motor 12 is arranged on the rotating shaft of the rotating part 5 in order to obtain rotation.

13 is a stator that supplies a rotating magnetic field from the outside, and 14 is a rotor made of permanent magnets or the like.

The type of electric motor may be one that does not contact rotating members, such as an induction type or a brushless motor. Magnetic bearings 9 and 10 hold the rotating shaft frictionlessly by using magnetic repulsion.

9 is a fixed side magnet, and an electromagnet may be used.

The holding part 4 is rotatable by a bearing 15. When this device is at rest, the rotating part 5 and the holding part 4 are in close contact with each other due to gravity.

By driving the electric motor 12, the rotating part 5 and the holding part 4 simultaneously start rotating and start sucking the medium 8 from the suction part 10 having a suction mechanism. At a predetermined rotation speed, the rotating part 5 floats due to the ejection force of the medium 10 from the ejection port 6, and the rotating part 5 and the holding part 4
leaves. The rotation of the holding part 4 stops due to friction of the bearing 15, etc., but since the rotating part floats above the holding part 4, the load due to friction is extremely reduced, making it possible to maintain rotation at a very high rotation speed. . FIG. 4 shows a system in which the holding part 4 is connected to an electric motor 16, the holding part 4 is rotated, and the rotating part 5 is levitated at a predetermined rotational speed.

In this case, the rotating part 5 repeats the process of decreasing its rotational speed, being supplied with rotation by the holding part again, and floating. Fifth
The figure shows the shapes of opposing surfaces of the rotating part 5 and the holding part 4 to prevent the rotating part 5 from being displaced in the lateral direction.

a is a cross-sectional view of a conical shape, and 6 indicates a medium ejection port. b
is a hemispherical cross-sectional view. c indicates a holding portion having a shape that fits into the concave rotating portion. In addition, the medium ejection ports 6 are arranged symmetrically around the central axis of rotation, or regularly arranged on concentric circles to prevent displacement of the position of the rotating part, etc., and to adjust the ejection flow rate to each mechanism 17. By attaching them, the amount of ejection from each ejection port can be adjusted to be the same. FIG. 6 shows a system in which the medium is supplied in both directions of the rotating shaft and held at both ends of the rotating shaft, and can be used even when the shaft is installed horizontally.

A spring 18 is used instead of gravity to bring the rotating part and the holding part into close contact, and the rotation is performed by the electric motor 12 in the same manner as described above. Therefore, when a predetermined rotation is reached, the ejection force becomes greater than the force of the spring, and the rotation is held and rotated without contact. By storing the above-described device in a sealed container and circulating the medium therein, loss of the medium can be prevented and the efficiency of ejection can be increased. I believe that the gist of the present invention has become clear from the above, but it goes without saying that the shape and structure of the movable holding part are not limited to those described above, and can be applied as appropriate.

[Brief explanation of the drawing]

Figures 1a to 1c are diagrams showing the directions of jet flows produced by members having various shapes, Figure 2 is a basic configuration diagram of the present invention, and Figure 3 is a specific embodiment of the present invention, in which an electric motor is installed in the rotating part. Fig. 4 shows an example with a mechanism for rotating the holding part, Figs. 2 is a diagram of a device in which the rotating part is held in close contact with the holding part by the force of a spring and held at both ends of the rotating shaft. 4... Holding part, 5... Rotating part, 6...
...Ejection port, 7...Medium path, 8...
- Absorption mechanism section, 10... Medium, 9 and 11...
... Magnet, 12 and 16 ... Electric motor, 15
...Bearing, 17...Flow rate adjustment mechanism, 1
8... Spring.

Claims (1)

[Scope of Claims] 1. A rotating part, a holding part having a structure capable of rotating at the same time as the rotating part, and a suction mechanism provided on the rotation axis of the rotating part; The surrounding medium sucked by the absorption mechanism is guided to the part that holds the rotating part through a medium guiding path provided in the axial direction of the rotating part, and the jetting of the medium causes the rotating part to maintain an appropriate gap. A movable holding device characterized in that at least part of the movable holding device has a mechanism that is held by the holding portion via the holding portion. 2. The scope of the above claim, wherein the opposing surfaces of the rotating part and the holding part have a conical shape, a hemispherical shape, or a concave shape to prevent displacement in a direction perpendicular to the rotation axis. The movable holding device according to item 1. 3. The movable holding device according to claim 1, wherein a rotor is provided on the shaft of the rotating part, and a stator is provided around the rotor, so that the movable holding device rotates as an electric motor. 4. The movable holding device according to claim 1, further comprising a rotation device for rotating the holding portion. 5. The movable holding device according to claim 1, characterized in that a plurality of medium jet ports are provided around the rotation axis of the rotating portion. 6. The movable holding device according to claim 1, characterized in that a suction mechanism is provided at a predetermined location of the rotating section to suck the medium into the medium guide path by rotation of the rotating section. 7. The movable holding device according to claim 1, further comprising a non-contact bearing on a rotating shaft different from that of the rotating portion and the holding portion.