JP2817220B2 - Micro bearing mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Summary] Regarding a micro-bearing mechanism, an object of the present invention is to provide a friction reducing mechanism applied to various slide surfaces in an extremely small mechanical device, and a surface area having no wettability to liquid. A first substrate in which a plurality of independent regions having wettability with respect to the liquid are disposed, and a surface of the first substrate which is wet and adheres to the plurality of regions having independent wettability The liquid comprising a liquid raised above by surface tension and a second base having a surface having no wettability with respect to the liquid;
The micro-bearing mechanism is characterized in that the base and the second base are in contact with each other with the liquid interposed therebetween.

[Industrial applications]

The present invention relates to a micro bearing mechanism applied to a very small mechanical device.

In recent years, with the advancement and development of mechatronics technology, applications of various robots and control devices have been increasingly active.

In particular, recently, important fields requiring ultra-miniaturization, such as applications to living organisms and space equipment, have been expanding, and how to reduce the frictional resistance of the slide surface of the micro-mechanical device used in these is important. This is a problem, and there is a strong demand for the development of a microminiature friction reduction mechanism.

[Conventional technology]

FIG. 6 is a diagram showing an example of the configuration of a conventional flat bearing, which is a method of reducing friction between two solid surfaces, which is very commonly used. In the figure, 40 is a fixed part, 60 is a moving part, 100
Is a lubricant such as a lubricating oil. That is, the frictional resistance when the two solid surfaces of the fixed portion 40 and the moving portion 60 slide is reduced through the lubricating oil, and is widely used from large to small mechanical devices. It is well known that lubricating oil also has a great function as a coolant for removing heat generated on the slide surface.

However, it is practically almost impossible to apply the above-described friction reduction mechanism to a micro-mechanical device or a mechanical element which is being developed recently.

At present, micro-mechanical devices that are considered to be used for special purposes have extremely small sizes of less than 1 mm or less than several 100 μm.
Some use special processing that makes full use of process technology.

FIG. 7 is a cross-sectional view showing an example of a bearing configuration of a conventional microlink mechanism (see Journal of Precision Engineering, 54/9/1988, p11).

FIG. 1A shows a cross-sectional view of the intermediate process, and FIG. 2B shows a cross-sectional view of each of the finished products. That is, the layers of the phosphosilicate glass 71, 70 and the polysilicon 42, 61 are alternately patterned on the silicon substrate 41, and are each formed by a vapor deposition method (CVD method). At this time, the polysilicon is etched to take the form of a mechanical member,
On the other hand, the phosphosilicate glass is laminated so as to be buried in a portion corresponding to the gap between the mechanism members, and then subjected to selective etching in which only the phosphosilicate glass is dissolved, so that the polysilicon The mechanism, that is, the shaft 61 'and the rotating arm 42' are assembled to complete the microlink mechanism.

In this example, the length of the rotary arm 42 'is as small as 150 μm.

Therefore, in such an extremely small mechanical device or mechanical element, as seen in the above-described example of the microlink mechanism,
At present, no special bearing mechanism is provided, and at most, the sliding surfaces are configured to be small and friction is suppressed as much as possible.

[Problems to be solved by the invention]

However, in the future, even with extremely small mechanical devices and mechanical elements, those with relatively large load capacity or those requiring a slide surface for high-speed movement will increase.
The means of simply reducing the slide surface as in the conventional example described above has a problem that a stable and reliable rotation or slide mechanism cannot be obtained.

[Means for solving the problem]

In the surface area 2 having no wettability to the liquid 1,
A first substrate on which a plurality of independent regions having wettability with respect to the liquid are disposed; and a first substrate which is wet and adheres to the plurality of independent regions and rises on the surface of the first substrate by surface tension. Liquid 1 and a second substrate 6 having a surface 5 having no wettability with respect to the liquid 1. The first substrate 4 and the second substrate 6 can be slid across the liquid 1. The problem can be solved by a micro-bearing mechanism configured so as to make contact with each other.

[Action]

According to the present invention, independent regions 3 having wettability to the liquid 1 are formed at a plurality of locations on the surface region 2 of the first base 4, and the surface tension in the region 3 is preferably as large as possible. When the liquid 1 is placed in close contact with, for example, a hemisphere, the surface of the other substrate 6 is coated with a material having no wettability with respect to the liquid 1, and the substrates 4 and 6 are brought into contact with the liquid 1. Since a plurality of lumps work just like the ball and lubricating oil of a conventional rolling bearing mechanism, they have a relatively large load capacity and are stable as a micromechanical device or a mechanical element that requires high-speed movement. Operation becomes possible.

〔Example〕

FIG. 1 is a diagram showing a configuration of a first embodiment of the present invention.
2A is a perspective view, FIG. 2B is an AA ′ cross-sectional view (at low load), and FIG. 2C is a BB ′ cross-sectional view (at high load).

In the drawing, 1 is preferably a liquid having a surface tension as large as possible, for example, mercury, 2 is a surface area having no wettability,
For example, an SiO ₂ or polyimide resin film, 3 is a region having high wettability, for example, a metal pattern made of Ni or Cr, 4 is a first substrate, for example, glass or Si, 5
Is a surface having no wettability, for example, a SiO ₂ or polyimide resin film, and 6 is a second substrate, for example, glass or Si.

As shown in FIGS. 2A and 2B, a liquid 1 having a high surface tension, such as mercury, is well wetted and strongly fixed to a region 3 having a high wettability, such as a circular Ni portion.
The first base 4 has a hemispherical swelling on the surface. On the other hand, the surface of the second substrate 6 is covered with a non-wetting surface, for example, a polyimide resin film. There is no direct contact between the surfaces of the substrates.

However, when the load applied between the two substrates increases, the hemispherical mercury is crushed as shown in FIG.
Although the distance between the surfaces of both substrates is reduced, the diameter of each mercury particle,
That is, since the peripheral length is increased, the internal pressure due to the surface tension is increased, and the gap is stabilized at a gap balanced with an external load.

In this state, when a sliding force acts between the two substrates, the second substrate 6
Is covered with a non-wetting surface 5,
It can slide very smoothly without the adhesion of mercury.

Controlling the frictional resistance, load-bearing characteristics, and high-speed operation characteristics by selecting the size of the regions 3 having high wettability and the distance between the regions, and by selecting the type of liquid having a high surface tension. Can be.

Now, the manufacturing steps for realizing the apparatus of the present invention as described above will be specifically described below in the order of steps.

FIG. 2 is a sectional view showing an example of the manufacturing process of the device according to the second embodiment of the present invention.

Step (1): Thickness on a 100 μm thick silicon substrate
A second substrate 6 is prepared by forming a 0.5 μm polyimide resin layer by spin coating.

Step (2): On the silicon substrate also having a thickness of 100 μm, a Ni film having a thickness of 0.5 μm to be a region 3 having high wettability is formed by a vacuum evaporation method.

Step (3): On the Ni film of the processed substrate, a thickness of 0.5
A μm polyimide resin layer is formed by spin coating.

Step (4): The polyimide resin layer of the processed substrate is
A hole for fixing the liquid 1 having a large surface tension is formed by photoetching or ion etching on the bottom surface.
The first substrate 4 is prepared by exposing the Ni film.

Step (5): A liquid 1 consisting of hemispherically raised mercury particles is formed on the exposed surface of the treated substrate by electroplating, for example, using an Ni film as a cathode in an aqueous Hg (NO ₃ ) ₂ solution.
To form

Step (6): The first substrate 4 and the second substrate 6 are brought into contact with each other so as to be slidable with the liquid 1 composed of the electrolytically deposited mercury particles therebetween. If the whole is configured together with a housing not shown, the micro bearing mechanism of the present invention can be formed.

It is needless to say that the manufacturing method of the above embodiment is merely an example, and other materials and manufacturing processes can be appropriately used in combination to constitute the micro bearing mechanism of the present invention. FIG. 3 is a view showing the configuration of the embodiment. First, a layer to be a surface region 2 having no wettability is formed on a first base 4, and a plurality of independent regions 3 having high wettability are formed thereon. And a liquid 1 having a high surface tension thereon.
Are fixed in a hemispherical shape, and then the second base 6 formed in the same manner as in the second embodiment is combined. If an easy-to-manufacture configuration can be appropriately selected according to a combination of materials, processes and the like. Good.

FIG. 4 is a view showing the configuration of a fourth embodiment of the present invention. FIG. 4A is a sectional view taken along the line AA ', and FIG. 4B is a side view.
This embodiment is a case where the present invention is applied to a so-called rolling bearing, and the sliding surface of the first base 4 is a circular inner surface of a cylindrical body.
The liquid 1 having a high surface tension is provided there. on the other hand,
The second substrate 6 is configured to form a non-wetting surface 5 on the outer surface thereof with a round bar so as to come into contact with the liquid 1 having a high surface tension.

FIG. 5 is a view showing a configuration of a fifth embodiment of the present invention, in which the present invention is applied to a so-called pivot bearing, in which a first base 4 is a fixed portion, and a surface is formed on an inner surface of a conical hole formed therein. A liquid 1 with high tension is provided. On the other hand, the second substrate 6 is a round bar serving as a turning axis, and the tip is machined in a conical shape. The outer surface of the second substrate 6 forms a surface 5 having no wettability, and comes into contact with the liquid 1 having a high surface tension. It is configured as follows.

It should be noted that the configurations of the above embodiments are all specific examples, and it goes without saying that the present invention is not limited to these examples, but can be widely applied to other shapes and designs.

〔The invention's effect〕

As described above, according to the present invention, the first base 4
Independent portions having good wettability are formed at a plurality of predetermined places on the surface having poor wettability, and liquid 1 having a large surface tension is formed there.
Are arranged closely in a hemispherical shape, for example, and the other substrate 6
Is coated with a material that does not wet with the liquid 1, and when both substrates are brought into contact with the liquid 1 therebetween, the mass of the liquid 1 having a large surface tension is exactly equal to the ball and lubricating oil of the conventional rolling bearing mechanism. Since it works as described above, it has a relatively large load capacity and is extremely useful as a bearing mechanism for extremely small mechanical devices and mechanical elements requiring high-speed movement.

[Brief description of the drawings]

FIG. 1 is a view showing a configuration of a first embodiment of the present invention, FIG. 2 is a sectional view showing an example of a manufacturing process of an apparatus of a second embodiment of the present invention, and FIG. 3 is a third embodiment of the present invention. FIG. 4 is a diagram showing a configuration of a fourth embodiment of the present invention, FIG. 5 is a diagram showing a configuration of a fifth embodiment of the present invention, and FIG. 6 is a configuration of a conventional flat bearing. FIG. 7 is a diagram showing an example of a bearing configuration of a conventional microlink mechanism. In the figure, 1 is a liquid having a large surface tension, 2 is a surface region having no wettability, 3 is a region having a high wettability, 4 is a first substrate, 5 is a surface having no wettability, and 6 is a second surface. The substrate.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F16C 17/04 F16C 33/10

Claims (1)

(57) [Claims] A first substrate provided with a plurality of independent regions having wettability with respect to the liquid in a surface region having no wettability with respect to the liquid; The liquid comprising a liquid which is wet and adhered to a region having wettability and is raised on the surface of the first substrate by surface tension, and a second substrate having a surface having no wettability with respect to the liquid; A micro bearing mechanism, wherein the first base and the second base are brought into contact with the liquid interposed therebetween.