JP2016167957A - Power transmission system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure smooth relative movement of two electrodes forming a junction capacitance, in a power transmission system to which an electric field coupling power transmission technique is applied.SOLUTION: In a slide or rotation power transmission system for transmitting power by using an electric field coupling power transmission technique, an electrode pair forming the coupling capacitance in the electric field coupling power transmission technique is constituted of an external conductor 22 and a connector external electrode 31. The external conductor 22 and connector external electrode 31 move relatively each other. Between the electrodes of the electrode pair, a minimum gap d is provided by a repulsive force generated when the connector external electrode 31 moves, because pressing pressures 82, 85 having at least a component in a direction substantially perpendicular to the direction of movement 83 of the connector external electrode 31 act between the electrodes.SELECTED DRAWING: Figure 18

Description

  The present invention relates to a power transmission system.

The present inventor has already invented the “electric field coupling method” as a new method of electric power transmission, and has further already described a circuit technology capable of realizing the new method (hereinafter referred to as “electric field coupling electric power transmission technology”). Invented (see Patent Document 1).
In electric field coupled power transmission technology, two metal plates (conductive plates) are made to face each other, and a capacitor (such a capacitor is hereinafter referred to as a “junction capacitance”) is formed using these two metal plates as electrode pairs. In this state, non-contact power transmission is realized by flowing a high-frequency current.

  A power transmission system to which electric field coupled power transmission technology is applied includes a power transmission unit that transmits power from a power source, and a power reception unit that receives power from the power transmission unit and supplies the power to a load. In this case, the junction capacitance is formed by making the metal plate (electrode) provided at the end of the power transmission unit and the metal plate (electrode) provided at the tip of the power reception unit face each other.

JP 2009-38329 A

As a form of the power transmission system to which the electric field coupling power transmission technique is applied, there are a slide system and a rotary system in which the two electrodes forming the junction capacitance move relatively.
In such a slide system or rotation system, the relative movement of the two electrodes forming the junction capacitance may not be smoothly performed during mounting.

  The present invention has been made in view of such circumstances, and in a power transmission system to which electric field coupling power transmission technology is applied, the relative movement of two electrodes forming a junction capacitance can be smoothly performed. It aims to be.

The power transmission system of one embodiment of the present invention is:
A slide-type or rotary-type power transmission system that transmits electric power using electric field coupled power transmission technology,
An electrode pair for forming a coupling capacitance in the electric field coupled power transmission technology, the electrode pair having a relatively moving electrode,
Generated when the electrodes move relative to each other due to a pressing pressure or a force based on the pressing force having at least a component in a direction substantially perpendicular to the moving direction of the electrodes between the electrodes of the electrode pair. A gap with a minimum gap caused by a repulsive force is provided, or a gap with a minimum gap is provided while reducing the frictional force during movement,
It is a power transmission system.

  In the power transmission system to which the electric field coupled power transmission technology is applied, the relative movement between the two electrodes forming the junction capacitance is smoothly performed.

It is a perspective view which shows the external appearance structure of the coaxial line with a slit as one Embodiment of the electric power transmission system with which this invention is applied. It is the figure which showed typically the outline of the cross-sectional structure of the coaxial line with a slit of FIG. 1, and the outline of the equivalent circuit of electric power transmission. 1 is a basic circuit diagram of electric field coupling for explaining an outline of electric field coupling power transmission technology. It is the figure which classified the problem of the tribology between the electrodes which have relative velocity. It is an expanded sectional view of an external conductor and a connector external electrode for explaining a problem of wear and tribology of cutting powder. It is an expanded sectional view of an external conductor and a connector external electrode showing the form of friction. It is a figure which shows the requirements of an electric power transmission system. It is the figure which classified the basic measure with respect to the tribology problem. It is a figure which shows an example of the method of combining various techniques with respect to the basic countermeasure of FIG. It is a schematic diagram which shows a mode that the corresponding | compatible technique of a solid lubricant was applied with respect to the coaxial line with a slit of FIG. It is a figure which shows typically the point contact site | part of a solid lubricant. It is an expanded sectional view of an external conductor and a connector external electrode which shows a mode that the correspondence technique of a solid lubricant was applied with respect to the coaxial line with a slit of FIG. It is a figure which shows the experimental result which slid the molybdenum disulfide and the slider, Comprising: It is a figure which shows the relationship between stop time and resistance increase rate. It is an equivalent circuit diagram which shows a parallel resonant circuit as a circuit for implement | achieving the electric field coupling electric power transmission technique at the time of applying the corresponding technique of a solid lubricant. It is an equivalent circuit diagram which shows the circuit which juxtaposed the direct current power transmission circuit as a circuit for implement | achieving electric field coupling electric power transmission technique at the time of applying the corresponding | compatible technique of a solid lubricant. It is an equivalent circuit diagram which shows the various examples of the circuit for implement | achieving electric field coupling electric power transmission technique. It is an expanded sectional view of an external conductor and a connector external electrode each coated with a sliding film. It is an expanded sectional view of an external conductor and a connector external electrode in a state where each sliding film is exposed without coating. It is an expanded sectional view of the external conductor and the connector external electrode which were each affixed with respect to the foaming member. It is a figure which shows the relationship between the friction coefficient at the time of vibrator | oscillator On / Off, and speed. FIG. 21 is an enlarged cross-sectional view of an external conductor and a connector external electrode for schematically explaining the relationship at the time of vibrator On in FIG. 20. It is an expanded sectional view of an external conductor and a connector external electrode which shows a mode that the correspondence technique of an ultrasonic contact was applied with respect to the coaxial line with a slit of FIG. It is an expanded sectional view of an external conductor and a connector external electrode which shows a mode that the correspondence technique of an ultrasonic contact was applied with respect to the coaxial line with a slit of FIG. It is an expanded sectional view of an external conductor and a connector external electrode which shows a mode that the corresponding | compatible technique of the electrode with a magnet was applied with respect to the coaxial line with a slit of FIG. It is an expanded sectional view of an external conductor and a connector external electrode which shows a mode that the magnet is shifted with respect to the state of FIG. It is a figure which shows the structure of the electric power transmission bearing using a liquid sealing type electrode. It is an enlarged view which shows the structure of the part of junction capacity among the electric power transmission bearings using the liquid sealing type electrode of FIG. It is sectional drawing of the electric power transmission bearing to which the corresponding technique of a solid lubricant is applied as another embodiment of the electric power transmission system to which this invention is applied. It is sectional drawing of the electric power transmission bearing which applied the corresponding | compatible technique of the minimum gap as another embodiment of the electric power transmission system with which this invention is applied. It is a perspective view which shows the outline of the basic composition of the slip ring as another embodiment of the electric power transmission system with which this invention is applied.

  Hereinafter, embodiments of the present invention will be described in detail.

FIG. 1 is a perspective view showing an external configuration of a coaxial line with slits as an embodiment of a power transmission system to which the present invention is applied.
The slit coaxial line 11 is a power transmission system to which an electric field coupling power transmission technique is applied.
The coaxial line 11 with a slit is attached so that a load (camera or the like) driven by electric power can be freely moved along the slit, and can transmit electric power to the load regardless of its position (even during movement). .
The slit coaxial line 11 is configured to include a connector 21, an outer conductor 22, and an inner conductor 23.

  The connector 21 is a component that can be freely moved along the slit while attaching a load and supplying power to the load, and includes a conductive connector external electrode 31 and a connector internal electrode 32. The connector external electrode 31 and the connector internal electrode 32 will be described later with reference to FIGS.

The outer conductor 22 is a conductive member having a rectangular parallelepiped shape inside, and functions as a line extending in a rod shape in a predetermined direction, for example, like a curtain rail disposed on a wall of an office or factory.
That is, a predetermined surface (a surface not shown in FIG. 1 and hereinafter referred to as “back surface”) of the outer conductor 22 is connected to an office or a factory wall or the like like a curtain rail.
As shown in FIG. 1, slits are formed in the longitudinal direction of the outer surface (hereinafter referred to as “front surface”) opposite to the back surface.
The connector 21 is attached so as to be movable along the slit. That is, the connector 21 moves freely along the slit of the external conductor 22 with a load (not shown) attached.

  The inner conductor 23 is a rod-shaped conductive member that is disposed in the inner space of the outer conductor 22 and extends in substantially the same direction as the longitudinal direction of the outer conductor 22.

FIG. 2 is a diagram schematically showing an outline of a sectional configuration of the coaxial line with slits 1 of FIG. 1 and an outline of an equivalent circuit for power transmission.
As shown in FIG. 2, the surface of the external conductor 22 and the predetermined surface of the connector external electrode 31 of the connector 21 are arranged to face each other. Such a pair of external conductor 22 and connector external electrode 31 form a junction capacitance Cc in the electric field coupling power transmission technique.
Further, the predetermined surface of the internal conductor 23 and the predetermined surface of the connector internal electrode 32 of the connector 21 are arranged to face each other. The paired internal conductor 23 and connector internal electrode 32 form a junction capacitance Cc in the electric field coupled power transmission technique.

Here, with reference to FIG. 3, the outline of the electric field coupling power transmission technique using such a junction capacitance Cc will be described.
FIG. 3 shows a basic circuit diagram of electric field coupling for explaining the outline of the electric field coupling power transmission technique.

As described above in the section “Background Art”, the electric field coupled power transmission technology is a non-contact power method in which a high frequency current is passed in a state where a junction capacitor Cc is formed by facing two metal plates as electrodes. This technology realizes electric transmission.
That is, an electrode (metal plate) is attached to the end of the power transmission unit 51 that transmits power from the power source Vf, and an electrode (metal plate) is attached to the tip of the power reception unit 41 that receives the power and supplies it to the load R. By forming the junction capacitance Cc by making these pairs of electrodes face each other, an electric field coupled power transmission technique is realized.
As described above, in this embodiment, the junction capacitance Cc is formed by the pair of the external conductor 22 and the connector external electrode 31 and the pair of the internal conductor 23 and the connector internal electrode 32.
Thus, since the power receiving unit 41 can be physically separated from the power transmitting unit 51 within a range in which the junction capacitance Cc can be formed, non-contact power transmission becomes possible.

  Electric power transmission with such a distance between the electrodes of the junction capacitance Cc forms an electric field in the peripheral space. For this reason, in many cases, an application mode in which the electrode spacing is close to each other is required so that electromagnetic radiation to the outside is reduced. In many cases, it is required to supply a certain amount of power to the load R.

つまり、一定の電力を伝送するための可変パラメータは、接合容量Ｃｃ、接合容量Ｃｃに流れる電流ｉ、及び接合容量Ｃｃに印加される電圧Ｖｃとなる。電流ｉと電圧Ｖｃのうち少なくとも一方を抑えることが要求されることが多く、このような要求に応えるためには、式（１）より、接合容量Ｃｃを大きくすればよい。 Here, the current i flowing through the junction capacitance Cc is expressed by the following equation (1) using the voltage Vc applied to the junction capacitance Cc as a parameter.

That is, the variable parameters for transmitting constant power are the junction capacitance Cc, the current i flowing through the junction capacitance Cc, and the voltage Vc applied to the junction capacitance Cc. In many cases, it is required to suppress at least one of the current i and the voltage Vc. In order to meet such a requirement, the junction capacitance Cc may be increased from the equation (1).

式（２）に示すように、接合容量Ｃｃを大きくするためには、電極間距離ｄを小さくするか、電極面積Ｓを大きくするか、又は電極間の誘電率εを大きくすることが求められる。即ち、電極面積Ｓを大きくしつつ、電極間距離ｄを十分に狭くできれば、大きな接合容量Ｃｃが実現できる。
ただし、本実施形態のようなスライド系や後述する回転系の実施形態では、接合容量Ｃｃは、相手との相対速度がある対の電極により形成される。この場合、実装の観点では、電極面積Ｓを大きくすることは容易であるが、電極間距離ｄの狭い間隔を維持することは困難である。
そこで、電極間距離ｄの狭い間隔を維持するための実装方法として、対となる電極の少なくとも一方に絶縁層を形成して、適度な力を加えてそれらを擦り合わせる方法を採用することができる。
この実装方法は、容易に実現できるため好適である。例えば上記実施形態でいえば、例えば、接合容量Ｃｃを形成する対の電極のうち、固定側の外部導体２２及び内部導体２３の夫々に対して、絶縁層を夫々形成すればよい。 Here, the junction capacitance Cc is expressed as the following equation (2), where d is the distance between the electrodes, S is the electrode area, and ε is the dielectric constant between the electrodes.

As shown in the equation (2), in order to increase the junction capacitance Cc, it is required to decrease the inter-electrode distance d, increase the electrode area S, or increase the dielectric constant ε between the electrodes. . That is, a large junction capacitance Cc can be realized if the inter-electrode distance d can be sufficiently narrowed while increasing the electrode area S.
However, in the embodiment of the slide system as in the present embodiment and the rotation system described later, the junction capacitance Cc is formed by a pair of electrodes having a relative speed with the counterpart. In this case, from the viewpoint of mounting, it is easy to increase the electrode area S, but it is difficult to maintain a narrow distance between the electrode distances d.
Therefore, as a mounting method for maintaining a narrow gap between the electrodes d, a method in which an insulating layer is formed on at least one of the pair of electrodes and an appropriate force is applied to rub them together can be employed. .
This mounting method is preferable because it can be easily realized. For example, in the above embodiment, for example, an insulating layer may be formed for each of the fixed-side outer conductor 22 and the inner conductor 23 of the pair of electrodes forming the junction capacitance Cc.

However, even if such a mounting method is adopted, a problem of tribology occurs in the case of the junction capacitance Cc formed from a pair of electrodes having a relative speed with the counterpart.
Therefore, the problem of tribology will be described below.
In the following description, for convenience of explanation, a pair of the external conductor 22 and the connector external electrode 31 is referred to as a pair of electrodes having a relative speed with the counterpart. However, the problem of tribology is a problem with respect to the entire junction capacitance Cc formed from a pair of electrodes having a relative speed with the counterpart, including the junction capacitance Cc formed by the internal conductor 23 and the connector internal electrode 32. .

FIG. 4 is a diagram in which problems of tribology between electrodes having relative velocities are classified.
As shown in FIG. 4, the problems are roughly classified into wear α, friction β, dust adhesion γ, and cutting powder δ.
The main cause of wear α is peeling of the surface material (collision between the convex portions).
The friction β is further divided into the problems of friction β1, friction β2, and friction β3 depending on the main cause. The main cause of the friction β1 is a catch between the convex portions on the rough surface. The main cause of the friction β2 is adhesion (metal bond, van der Waals force, electrostatic force) on the mirror surface. The main cause of friction β3 is adhesion (liquid meniscus).
The main causes of dust adhesion γ are sticky dust (organic) and hard dust (sand dust).
The main cause of the cutting powder δ is the cutting powder of the rail and the slide body.

In other words, the electric field coupled power transmission technique can originally perform non-contact power transmission, but when the distance between the electrodes is very narrow as in this embodiment, the wear α, friction β, and dust shown in FIG. The problem of tribology of adhering γ and cutting powder δ is not without.
In addition, the electric field coupled power transmission technology is not only used alone, but may be used in combination with electric power transmission by conduction. When combined with electric power transmission by conduction, the interface is naturally brought into a form of mounting, so the problem of tribology of wear α, friction β, dust adhesion γ, and cutting powder δ shown in FIG.
Therefore, it is necessary to take measures against the tribology problems of wear α, friction β, dust adhesion γ, and cutting powder δ shown in FIG.
Accordingly, the tribology problems of wear α, friction β, dust adhesion γ, and cutting powder δ will be briefly described below, and countermeasures thereof will also be described.

First, the problem of tribology of wear α, dust adhesion γ, and cutting powder δ will be described with reference to FIG.
FIG. 5 is an enlarged cross-sectional view of the external conductor 22 and the connector external electrode 31 for explaining the problem of tribology of the wear α and the cutting powder γ.
As shown in FIG. 5, the connector external electrode 31 as the moving body moves in the direction indicated by the arrow in the figure with respect to the external conductor 22 as the fixed body.

  In this case, as shown in FIG. 5A, the convex portions of the interfaces between the external conductor 22 and the connector external electrode 31 collide with each other. Then, in this collision part 61, a convex part is damaged and the cutting powder 62 falls. That is, the problem of wear α and cutting powder δ occurs in the collision portion 61 of the convex portion of the interface.

On the other hand, FIG. 5C shows a state in which hard dust 63 is sandwiched between the external conductor 22 and the connector external electrode 31 and rubbed and worn.
The hard dust 63 rolls between the external conductor 22 and the connector external electrode 31, scratches the respective surfaces of the external conductor 22 and the connector external electrode 31, and drops the cutting powder 62.
The cutting powder 62 makes new scratches on the surfaces of the external conductor 22 and the connector external electrode 31.
In this way, the tribological problem of friction α and dust adhesion γ occurs.
Further, the problem of tribology of dust adhesion γ is caused not only by the hard dust 63 but also by organic dust such as spider webs and mosses. That is, the organic dust does not damage the external conductor 22 and the connector external electrode 31, but the connector external electrode 31 is lifted with respect to the external conductor 22. May corrode.

Next, the tribology problem of the friction β will be described with reference to FIG.
FIG. 6 is an enlarged cross-sectional view of the external conductor 22 and the connector external electrode 31 showing the form of the friction β.

  As shown in FIG. 6A, the tribology problem of the friction β1 is caused by the collision between the convex portions of the external conductor 22 and the connector external electrode 31. That is, the main cause is the catching at the portion 61 where the protrusions collide.

  According to the concavo-convex theory, it is considered that the friction disappears if the concavo-convexity disappears, but actually, the frictional force increases when the flat metal plates face each other. This explanation can be explained by the adhesion phenomenon. That is, it can be explained as a tribological problem of the friction β2 and the friction β3.

FIG. 6B shows a state in which the external conductor 22 and the connector external electrode 31 are coupled at the flat portion 64 between the external conductor 22 and the connector external electrode 31.
This bond is assumed to be a metal bond (ringing).
Further, the force 65 due to the field acts around the flat portion 64 to enhance the adhesion. The field force 65 is an attractive force between charges such as van der Waals force. In the case of applying the electric field coupling power transmission technology, the attractive force accompanying power transmission can be regarded as one of them.
In this way, the tribological problem of friction β2 arises.

The tribology problem of the friction β3 with respect to the friction β2 is the same adhesion force, but the principle is different and a very large friction force is exhibited.
FIG. 6C shows a state in which the liquid 66 is sandwiched between the external conductor 22 and the connector external electrode 31.
When the amount of the liquid 66 is sufficient, the layer of the liquid 66 functions as a lubricating layer between the external conductor 22 and the connector external electrode 31.
However, when the amount of the liquid 66 is extremely small, when the area is large with respect to the thickness, the meniscus of the liquid 66 works, resulting in an extremely large frictional force. That is, the tribology problem of the friction β3 occurs.
Here, as the type of the liquid 66, in the case of water, the meniscus is large and the influence is particularly large. However, the same thing occurs with lubricating oil such as sewing oil. Regardless of wettability with the metal body, meniscus adhesion is observed even on a hydrophobic surface.

  The problem of tribology of wear α, friction β, dust adhesion γ, and cutting powder δ has been described above with reference to FIGS.

Further, when taking measures against the problem of the junction capacitance Cc formed from a pair of electrodes having a relative speed with respect to the other party, the requirements of the power transmission system (in this embodiment, the coaxial line with slits 1) are also taken into consideration. There must be.
FIG. 7 shows the requirements for the power transmission system.
The requirement 1 is a large and stable junction capacitance Cc.
The requirement 2 is to ensure low cost.
Requirement 3 is to ensure free maintenance.
Requirement 4 is to ensure long-term durability.

The present inventor has devised a countermeasure capable of solving the problem of tribology as shown in FIG. 8 after satisfying the requirements of such a power transmission system.
FIG. 8 is a diagram in which basic measures against the tribology problem are classified.
As shown in FIG. 8, the basic countermeasure technology can be broadly classified into a contact portion correspondence technology and other correspondence technologies.
Specifically, the technology corresponding to the contact portion includes a solid lubricant a, minimum gap maintenance b and c, ultrasonic contacts d and e, electrodes with magnets f and g, water-repellent coating / electrode heating h, anodization There is titanium material use i and liquid lubrication j.
As other technologies, there are air suction (1), dry air blowing (2), hot air blowing (3), cleaning robot (4), waterproofing measures (5), and moisture absorption measures (6). .
In FIG. 8, for each of these corresponding technologies, whether the load can be received, whether the power transmission form is AC only, whether DC and AC can flow simultaneously, the function and purpose of the DLC film, respectively. It is shown.

FIG. 9 is a diagram illustrating an example of a technique for combining various techniques with respect to the basic countermeasure of FIG.
As shown in FIG. 9, a new bearing structure technology can be combined with the solid lubricant a.
For the minimum gap maintenance b and c, it is possible to combine elastic body support and ultra-thin metal technology.
For the ultrasonic contacts d and e, it is possible to combine ultrasonic driving and DLC film technology.
Further, although not shown, the magnet-equipped electrodes f and g can be combined with various technologies for ultra-low cost.
In FIG. 9, circuits and features are shown for each corresponding technology to which a predetermined technology is combined.
9 is merely an example, and an arbitrary number of arbitrary combining techniques (including another corresponding technique in FIG. 8) are combined with an arbitrary number of arbitrary corresponding techniques in FIG. Is possible.

Here, when applying the corresponding techniques of FIG. 8 and FIG. 9, the problem of the DLC film and the electrode may be considered.
Therefore, the DLC problem and the electrode problem will be briefly described below.

First, the DLC film problem will be described.
In recent years, there is a film having mechanical strength, dielectric strength, and low frictional force, such as a DLC (Diamond-Like Carbon) film. By applying such a DLC film, it can withstand a slight contact, which helps to counter the problem of tribology. However, if long-term reliability is taken into consideration, it is not natural to rely solely on the strength of the DLC film.
In addition, even if a DLC film is used, in order to fully demonstrate its performance, the ground electrode is mirror-polished (micro-requirement) and a wrinkle-free state (macro-requirement) is realized. It is necessary to adhere.
In addition, it is said that the DLC film is peeled off with a surface accuracy where the convex portions strongly collide with each other.
Furthermore, even if the DLC film is applied, it is assumed that the problem of tribology of friction β2 and friction β3 due to adhesion force remains.
The above is the problem of the DLC film. As described above, although the application of the DLC film helps the countermeasure against the problem of tribology, the single application is not sufficient as a countermeasure, and another countermeasure needs to be used together. That is, as shown in FIGS. 8 and 9, it is preferable to apply the above-described various technologies and the DLC film.

There are the following problems as a problem of the DLC alone. In other words, DLC is an excellent material that has excellent sliding properties, low attack on the opposing material, and high adhesion and hardness, but has a low coefficient of linear expansion and a normal metal plate (ultra thin metal). There is a problem that warping occurs if it is coated.
Therefore, as a countermeasure against this single problem, there is a countermeasure such as 36Ni, Super Invar, which has a linear expansion coefficient equivalent to that of DLC, so that this is selected and coated on an extremely thin metal.
That is, in this specification, the DLC film includes not only a film formed using DLC as a material but also a film formed using a material having a linear expansion coefficient equivalent to that of DLC, such as 36Ni and Super Invar. It is a broad concept.

Next, the electrode problem will be described.
The metal plates such as the external conductor 22 and the connector external electrode 31 retain internal stress during processing, so that it is difficult to bring the two metal plates (electrodes) into close contact with each other even by mirror polishing. Become.
For this purpose, it is necessary to sufficiently anneal the metal plate itself as an electrode.
Actually, when annealing, the internal stress can be taken out, but it is distorted, so the mirror polishing must be repeated again. This is costly to produce and causes a problem with economy.

Such an electrode problem can be solved by using an ultrathin metal.
The ultrathin metal is a thin metal foil having a thickness of 5 to 100 μm. In particular, if a thickness of 20 μm or less is used, the variation in thickness is about ± 1 μm, so that mirror polishing is unnecessary. Furthermore, since an annealing process can be performed, those without internal stress are available.

  Further, the corresponding technologies in FIGS. 8 and 9 will be specifically described below.

[Solid lubricant a]
First, a technique for dealing with the solid lubricant a will be described.
Solid lubricants have been applied to bearing products that are conventionally used for heavy-duty equipment. That is, the conventional bearing product to which the solid lubricant is applied generally does not contain oil, and uses only the lubricating action of the solid lubricant.

FIG. 10 is a schematic diagram showing a state in which the corresponding technology for the solid lubricant a is applied to the slit coaxial line 1 of FIG.
For convenience of explanation, as shown in FIG. 10, only the case where the corresponding technology of the solid lubricant a is applied to the external conductor 22 and the connector external electrode 31 will be mentioned. However, the same applies. Furthermore, the present invention can be similarly applied to the entire junction capacitance Cc formed from a pair of electrodes having a relative speed with the counterpart.

The contact interface of solid lubrication between the external conductor 22 and the connector external electrode 31 is not in contact as a whole, but is in contact only at the point contact portion 67 in FIG. That is, only a part of the apparent contact area is in contact. Hereinafter, the contact area at the point contact portion 67 is referred to as “true contact area”.
In this case, as shown in FIG. 10, the apparent contact area S is represented by (a × b), but the true contact area is represented by the sum of the areas of the plurality of point contact sites 67.
Note that, when the pressing pressure 82 is increased, the area of at least a part of the point contact portion 67 increases, so that the true contact area also increases.

Here, the structure of one point contact part 67 and its vicinity is examined.
FIG. 11 is a diagram schematically showing a point contact portion 67 of the solid lubricant.
FIG. 11A is a side view of the point contact portion 67 of the solid lubricant. FIG. 11B is a plan view of the point contact portion 67 of the solid lubricant.
A region 68 around the point contact portion 67 becomes a gap between the external conductor 22 and the connector external electrode 31. That is, the region 68 of the outer conductor 22 and the connector outer electrode 31 has a very narrow gap, that is, a large capacitance. That is, this capacitance functions as a junction capacitance Cc in the electric field coupling type power transmission technology.

Here, the high-frequency current flowing between the external conductor 22 and the connector external electrode 31 can be divided into a conductive current component and a displacement current component. The ratio of the conductive current component and the displacement current component varies depending on the frequency and load. For example, the higher the frequency, the greater the rate of displacement current.
The conductive current component flows through the point contact portion 67 and the displacement current component flows through the surrounding area 68.
Therefore, if a conductive current component (DC current) is passed too much, the point contact portion 67 is melted by heat, leading to an increase in frictional force. For this reason, it is preferable that the conductive current component (DC component) be a minimum electric power transmission for starting up the system on the power receiver side.
However, the conduction current component is not likely to melt because the transmission current is limited due to the inductance of the point contact portion 67. In addition, since the surrounding region 68 is actually very close to the point contact portion 67, the surrounding region 68 has a large junction capacitance Cc, and the displacement current component becomes large.

FIG. 12 is an enlarged cross-sectional view of the external conductor 22 and the connector external electrode 31 showing a state in which the corresponding technology of the solid lubricant a is applied to the slit coaxial line 1 of FIG.
As shown in FIG. 12A, a solid lubricant 80 may be added to one of the contact surfaces (the surface on the connector external electrode 31 side in the example of FIG. 12), or as shown in FIG. The solid lubricant 80 may be added to both of the contact surfaces (in the example of the figure, the surface on the side of the external conductor 22 and the connector external electrode 31).
Since the solid lubricant 80 has a structure embedded in a yellow steel metal, when the same material faces each other (in the case of FIG. 12B), depending on the slip position, the yellow steel The metal plates may slide with each other or between the solid lubricants 80, or may slide with the yellow steel metal and the solid lubricant 80.
A typical material for the solid lubricant 80 is molybdenum disulfide.
Here, according to an experimental report of sliding molybdenum disulfide and a slider (copper-plated steel ball), after the friction was interrupted and restarted against the electrical resistance of the solid lubricant film before stopping It is said that there is a proportional increase in resistance depending on the length of the interruption period.
Although the cause is not discussed here, it is important to recognize that there is a fluctuation range in the contact resistance shown in FIG. 13 in the case of molybdenum disulfide (Hoshino; Production Technology, Volume 19). 9 (1967.9), pp. 18-20.).
That is, FIG. 13 is a diagram showing an experimental result in which molybdenum disulfide and a slider (a steel ball plated with copper) are slid, and is a diagram showing the relationship between the stop time and the resistance increase rate.

In addition, the measured value of the resistance of each part of the conventional bearing product to which the solid lubricant was applied was 0.2 to 0.4Ω within the same solid sliding material, and 0.1Ω within the yellow steel metal material. However, there were variations such as 20Ω, 50Ω, and Open between the yellow steel material and the solid sliding material.
In addition, when two conventional washer-type products to which a solid lubricant is applied are stacked (corresponding to both cases in FIG. 12 (b)), the measured value of resistance is between 0.2Ω and 2Ω, It varied depending on the position.
The results of measuring the resistance when a conventional washer-type product to which a solid lubricant is applied and a normal washer-type product are stacked (corresponding to one of the cases in FIG. 12A) are similar. It was.
From the measured values of these resistances, the point contact with the solid lubricant has a larger contact resistance than that of a normal metal contact, and therefore there is a possibility that the joining ratio due to the high-frequency displacement current can be increased. The operating frequency can also be determined.

Here, a circuit configuration for realizing the electric field coupling power transmission technology when the corresponding technology for the solid lubricant a is applied will be described.
FIG. 14 is an equivalent circuit diagram showing a parallel resonant circuit as a circuit for realizing the electric field coupled power transmission technique when the corresponding technique for the solid lubricant a is applied.
In the example of FIG. 14, the junction capacitance Cc is a parallel connection of a resistor Rc and an inductance Lc. The voltage is boosted n times by the first transformer of the power transmission unit 51 and is reduced to 1 / n by the transformer subsequent to the power reception unit 41. When the load resistance is R, the impedance of the new circuit for parallel use at the rear stage of the transformer is n ² R, so the current is 1 / n times.
That is, the voltage can be increased by n and the current can be reduced to 1 / n. Thereby, current heat generation at the point contact portion 67 can be reduced.
FIG. 14 is merely an example, and the first-stage transformer may be omitted if a high-frequency power supply Vf with a high output voltage is used. In the example of FIG. 14, a resonance circuit is inserted on the secondary side of the first-stage transformer and on the primary side of the rear-stage transformer. However, a resonance circuit is inserted on one or both of the primary side and the secondary side. May be.
The frequency may be determined by the ratio of the contact resistance of the solid lubricant, the reactance due to inductance, and the reactance due to capacitance.

Further, when a solid lubricant is used, a direct current (conductive current component) can also flow as described above. Therefore, a circuit in which direct current transmission circuits as shown in FIG.
FIG. 15 is an equivalent circuit diagram showing a circuit in which DC power transmission circuits are juxtaposed as a circuit for realizing the electric field coupled power transmission technology when the corresponding technology for the solid lubricant a is applied.
Here, the CPU 75 is a control unit that operates by direct current.
The DC / DC converter 76 has a function of converting a DC voltage supplied to the power receiving unit 41 into a voltage (current) that can be consumed by the CPU 75. That is, since it is considered that the output voltage varies depending on the contact state, the output voltage is stabilized by the DC / DC converter 76.
The DC load 77 is a load for the CPU 75, the DC resistance R, and other DC.
A choke coil Lp is inserted so that a high frequency component does not flow in the DC circuit. Further, a blocking capacitance Cp is inserted so that no direct current flows through the high-frequency circuit.
In this way, the DC circuit is considered to transmit weak power and supply control power for the power receiving device (power consumption of the CPU 75 in the example of FIG. 15). Depending on the application, a circuit that transmits only direct current may be employed.

Note that any of the circuits shown in FIG. 16 may be employed as the AC side circuit.
That is, FIG. 16 is an equivalent circuit diagram showing various examples of circuits for realizing the electric field coupling power transmission technique.
The various circuits in FIG. 16 can be adopted regardless of whether or not the corresponding technology for the solid lubricant a is applied, in other words, when the various corresponding technologies in FIGS. 8 and 9 are applied.
In FIG. 16, for convenience of explanation, the rectifier circuit and the smoothing circuit are omitted.
In addition, when a DC circuit is loaded on the various AC circuits shown in FIG. 16, it is not always necessary to adopt a DC circuit equivalent to FIG. 15, but the choke coil L and the cutoff capacitance Cp as shown in FIG. It is preferable that the DC circuit has

[Minimum gap maintenance b, c]
Next, a technique for dealing with the minimum gap maintenance b and c will be described.
The corresponding technology for the minimum gap maintenance b and c is a technology that uses the minimum contact load without applying a load to the contact electrode.
FIG. 17 is an enlarged cross-sectional view of the external conductor 22 and the connector external electrode 31 each coated with a sliding film.
For convenience of explanation, as shown in FIG. 17, only the case where the corresponding technique of the minimum gap maintenance b and c is applied to the external conductor 22 and the connector external electrode 31 will be mentioned. The same applies to. Furthermore, the present invention can be similarly applied to the entire junction capacitance Cc formed from a pair of electrodes having a relative speed with the counterpart.

In the example of FIG. 17, the external conductor 22 and the connector external electrode 31 have the surface roughness 81 minimized, that is, they are mirror-polished, and a sliding material such as DLC is applied to each surface. The sliding film 99 is laminated by coating.
The external conductor 22 and the connector external electrode 31 are in a state of being opposed to each other, and there is no macro deflection, but a micro surface roughness remains.
In the state of FIG. 17A, since the external conductor 22 and the connector external electrode 31 are opposed to each other by the weak pressing pressure 82, when the upper connector external electrode 31 moves in the movement direction 83, a repulsive force 84 is generated. .
As shown in FIG. 17B, the repulsive force 84 creates a gap d between the external conductor 22 and the connector external electrode 31. Since this gap d does not open to a surface roughness of 81 or more, it is hereinafter referred to as “minimum gap d”. In this way, when the minimum gap d is vacant, the pressure is returned with a slightly stronger pressing pressure 85.
By repeating such a state of FIG. 17A and FIG. 17B, the minimum gap d is formed.

In such a technique of maintaining the minimum gaps b and c, the force applied to the system is received by other methods such as a bearing, and the sliding film in the power transmission electrode is applied with a minimum force. When a DLC film is used as the sliding film 88, a strong adhesion strength can be obtained, but the life can be further extended by using a weak contact pressure.
As the DLC film, an insulating film and a conductive film can be selectively employed, so that direct current component can be transmitted. In order to make the minimum gap d, since contact is repeated somewhere, there is always a contact.

Here, as shown in FIG. 18, the sliding film 88 such as a DLC film is not an essential component in the technique of the minimum gap maintenance b and c.
FIG. 18 is an enlarged cross-sectional view of the external conductor 22 and the connector external electrode 31 in a state where the sliding film is exposed without coating.
Since the principle of the technique of the minimum gap maintenance b and c is the same as that in the case of FIG. 17, the description is omitted here.
Since the external conductor 22 and the connector external electrode 31 are exposed, it is preferable to use Ti or SUS, which can be expected to have anticorrosive properties, because the life can be extended and the frictional force can be reduced.

FIG. 19 is an enlarged cross-sectional view of the external conductor 22 and the connector external electrode 31 attached to the foam member.
The foam 90 is provided between the connector external electrode 31 and the predetermined moving body 91.
The foam 92 is provided between the outer conductor 22 and a predetermined fixed body.
The connector external electrode 31 and the external conductor 22 are made of ultrathin metal.
As a result, the connector external electrode 31 and the external conductor 22 need not be polished.
Further, since the connector external electrode 31 and the external conductor 22 are lightweight, pressure is applied by the pressing pressure of the foam 90 and the foam 92, respectively, even in the state of FIG.
Since this pressure corresponds to the weak pressing pressure 82 in FIG. 17A, when the upper connector external electrode 31 moves in the moving direction, a repulsive force (see the repulsive force 84 in FIG. 17) is generated at the contact point. .

Here, if the repulsive force of the contact point is vector-decomposed, it can be divided into a vertical force and a horizontal force.
The force in the vertical direction is a force that compresses the foam 90 and the foam 92 itself, and the force in the horizontal direction gives a shearing force to the foam 90 and the foam 92.
When such a shearing force is applied in the state of FIG. 19A, the foam 90 and the foam 92 move in an oblique direction as shown in FIG. 19B. As a result, the foam 90 and the foam 92 are reduced from the thickness D to the thickness D ′.
As in the example of FIGS. 17 and 18, the minimum gap d is formed by reciprocating the states of FIGS. 19A and 19B.

Thus, in the example of FIG. 19, it is not necessary to use the force applied from the outside as shown in FIGS. 17 and 18 as the pressing pressure. Moreover, when a contact area can be earned, it can fix with an adhesive.
In addition, the foam 90 and the foam 92 are good to use the thing of a closed cell with little secular change.
Various circuits shown in FIGS. 14 to 16 can be employed as the power transmission circuit. However, when an insulating sliding film is used, the conductive current component does not flow, so the circuit of FIG. 14 may be employed.
Further, the foam 90 or the foam 92 may be attached to one of the connector external electrode 31 and the external conductor 22 and may not be attached to the other.

In summary, the power transmission system to which the corresponding technology of the minimum gap maintenance b and c is applied is as follows.
A slide-type or rotary-type power transmission system that transmits electric power using electric field coupled power transmission technology,
An electrode pair for forming a coupling capacitance in the electric field coupled power transmission technology, the electrode pair having a relatively moving electrode,
Generated when the electrodes move relative to each other due to a pressing pressure or a force based on the pressing force having at least a component in a direction substantially perpendicular to the moving direction of the electrodes between the electrodes of the electrode pair. A gap with a minimum gap caused by a repulsive force is provided, or a gap with a minimum gap is provided while reducing the frictional force during movement,
It can be said that this is an electric power transmission system.
Here, the force based on the pressing pressure means that a force involving the pressing pressure is sufficient, and for example, a force obtained by adding a vibration force to the pressing pressure is applicable.

[Ultrasonic contact d, e]
Next, a technique for dealing with the ultrasonic contacts d and e will be described.
Between 1993 and 2003, Prof. Fujii of Gifu University studied to control the friction coefficient using ultrasonic vibration.
The inventor has invented a technique capable of transmitting power while reducing friction between the electrodes in the slide body and the rotating body based on the examination result.

FIG. 20 shows the relationship between the friction coefficient and the speed when the vibrator is On / Off.
This relationship is a representative trend extracted from a group of experimental data conducted at Gifu University. In FIG. 20, the vertical axis represents the friction coefficient, and the horizontal axis represents the moving speed. The broken line indicates the relationship when the transducer is turned off, and the solid line indicates the relationship when the transducer is turned on.

FIG. 21 is an enlarged cross-sectional view of the external conductor 22 and the connector external electrode 31 for schematically explaining the relationship at the time of the vibrator On in FIG.
In the case of the vibrator Off, as shown by a broken line in FIG. 20, the friction coefficient is large at a low speed, and the friction coefficient is lowered when the movement is performed. As a result, the result is equivalent to a normal friction experiment.
That is, the relationship corresponds to static friction at low speed and to dynamic friction when moved. The reason for this is that the state transitions in the order of FIGS. 21A, 21B, and 21C, as described in the concavo-convex theory. The portion bites into the recess (see FIG. 21A), and energy is required to escape from this biting. When the moving speed is increased, the convex portion cannot completely bite into the concave portion (see FIG. 21 (b) to FIG. 21 (c)), and it is considered that the energy required for escape is reduced.

On the other hand, in the case of the vibrator On, as shown by the solid line in FIG. 20, the friction coefficient is in a very low state and increases as the moving speed increases. That is, there is a relationship that static friction is eliminated.
This is because, as shown in FIG. 21 (d), when the vibration amplitude is substantially the same as or larger than the depth of the concavo-convex portion, the connector external electrode 31 is in a state of jumping up, so the friction becomes extremely low. .
However, it is considered that an increase in the friction coefficient is observed since the collision probability between the convex portions increases as the moving speed increases (see FIG. 21E).

  According to a report from Gifu University, the same effect can be obtained even if the direction of vibration is added vertically and horizontally (moving direction, direction orthogonal to the traveling direction).

As another method using ultrasonic waves, there is a method using an ultrasonic moving body.
The ultrasonic moving body has been put into practical use as an ultrasonic motor.

FIG. 22 shows a state in which the corresponding technology of the ultrasonic contacts d and e (technology of the ultrasonic moving body) is applied to the coaxial line with slits 1 in FIG. It is an expanded sectional view.
For convenience of explanation, as shown in FIG. 22, only the case where the corresponding technology of the ultrasonic contacts d and e is applied to the external conductor 22 and the connector external electrode 31 will be described. The same applies to. Furthermore, the present invention can be similarly applied to the entire junction capacitance Cc formed from a pair of electrodes having a relative speed with the counterpart.

As shown in FIG. 22, piezoelectric elements 93 are attached to the outer conductor 22 on the fixed body side at equal intervals. In this case, every other driving power source such as the transmitter 94 and the transmitter 95 is driven by shifting the phase by 90 ° to induce a surface acoustic wave, and by the rotational motion of the surface of the outer conductor 22, the moving body The connector external electrode 31 is moved.
That is, the transmitter 94 and the transmitter 95 each generate a voltage composed of a sine wave having the same amplitude and a phase shifted by 90 °.
The piezoelectric element 93 is an element that operates in the vertical direction with a voltage applied by the transmitter 94, the transmitter 95, etc., and has a function of changing the thickness of the external conductor 22.
The traveling wave is a wave generated in the direction opposite to the moving direction 83 due to the operation of the piezoelectric element 93.

FIG. 23 shows a state in which the corresponding technology of the ultrasonic contacts d and e (technology of the ultrasonic moving body) is applied to the coaxial line with slits 1 of FIG. It is an expanded sectional view.
In the example of FIG. 23, a DLC film 96 is formed on each of the external conductor 22 and the connector external electrode 31 as compared with the example of FIG.
Except for the DLC film 96, since it is similar to the example of FIG.

Various circuits shown in FIGS. 14 to 16 can be employed as the power transmission circuit. However, when the contact portion is conductive, it is preferable to employ the circuit of FIG. On the other hand, when the contact portion is not conductive, the circuit shown in FIG. 14 without a DC power transmission circuit may be employed.
In the case of applying the corresponding technology of the ultrasonic contacts d and e (the technology of the ultrasonic moving body) to the embodiment of the slide system such as the coaxial line 1 with slit of FIG. The electrode pairs are formed in two rows or front and back, respectively, to form two junction capacitors Cc (see FIG. 2 and the like).

[Electrodes with magnets f, g]
Next, a technique for dealing with the magnetized electrodes f and g will be described.
The above-described technology for the ultrasonic contacts d and e is a technology for actively applying vibration energy between electrodes. For this reason, a piezoelectric element, a transmitter, etc. are needed as mentioned above.
On the other hand, the technology for the magnetized electrodes f and g is a technology for passively applying vibration between the electrodes. For this reason, a piezoelectric element, a transmitter, etc. are unnecessary.

FIG. 24 is an enlarged cross-sectional view of the external conductor 22 and the connector external electrode 31, showing a state in which the corresponding technology for the electrodes with magnets f and g is applied to the slit coaxial line 1 of FIG. 1.
For convenience of explanation, as shown in FIG. 24, only the case where the corresponding technology of the electrodes with magnets f and g is applied to the external conductor 22 and the connector external electrode 31 will be mentioned, but the internal conductor 23 and the connector internal electrode 32 The same applies to. Furthermore, the present invention can be similarly applied to the entire junction capacitance Cc formed from a pair of electrodes having a relative speed with the counterpart.

Each of the external conductor 22 and the connector external electrode 31 is configured as a nonmagnetic ultrathin metal electrode.
On the connector external electrode 31, an adhesive layer 101, a rubber magnet 102, an adhesive layer 103, a foam 104, an adhesive layer 105, and a predetermined moving body 106 are laminated in that order in the upward direction in FIG.
24, the adhesive layer 107, the rubber magnet 108, the adhesive layer 109, the foam 110, the adhesive layer 111, and the predetermined fixing body 112 are laminated in that order in the lower direction in FIG.

FIG. 25 is an enlarged cross-sectional view of the external conductor 22 and the connector external electrode 31, showing a state where the magnet is displaced and the adsorption and repulsion force are obtained with respect to the state of FIG. 24.
The rubber magnet 102 and the rubber magnet 108 facing each other via the external conductor 22, the connector external electrode 31 and the like attract each other when the opposite poles face each other as shown in FIG. ) When the same poles face each other, they repel.
In such a state, when it is slid or rotated, vibration energy is applied to the external conductor 22 and the connector external electrode 31. Thereby, adhesion friction can be reduced.

24 and 25, the anisotropic rubber magnet 102 and the rubber magnet 108 are used to align the anisotropic direction, but an angle may be provided.
Further, in the case of an embodiment of a rotating body as will be described later, the anisotropy of rubber may be made radial.
Moreover, although the method using a rubber magnet was described, the method of arrange | positioning a separate magnet may be sufficient.
In the example of FIGS. 24 and 25, the magnet arrangement pitch of the rubber magnet 102 and the rubber magnet 108 is the same, but may be changed. By changing the pitch, it is always in contact somewhere, so continuous DC power transmission becomes possible. Furthermore, the starting torque can be reduced.

[Friction β3: Countermeasure for adhesion (liquid meniscus)]
Of the corresponding technologies described above, the electrodes with magnets f and g and the minimum gap maintenance b and c are effective in solving the friction β2 problem among the tribological problems of the friction β, but the problem of the friction β3 is solved. Is not effective.
Here, the problem of friction β2 is a problem of adhesion (metal bond, van der Waals force, electrostatic force). On the other hand, the problem of friction β3 is a problem of adhesion (liquid meniscus).
This adhesion by the liquid meniscus occurs when the amount of liquid is quite limited, but it must be careful when putting it to practical use because it exhibits an extremely strong adsorption force. Easy to peel.
Therefore, in order to prevent this, it is preferable to apply a corresponding technique of water repellent coating film / electrode heating h, anodized titanium material use i, or dry air spraying (2).
The water repellent coating film / electrode heating h is a technique for applying a water repellent coating film to one electrode and providing a heatable heater.
The use of anodized titanium material i is a technique using an anodized titanium thin film for one electrode. Irradiation with ultraviolet rays functions as a photocatalyst to prevent contamination, and can be superhydrophilic and water can be easily vaporized by heating with a heater.
Dry air blowing (2) is a technique of blowing dry air to the electrode contact portion. For example, in the embodiment of the slide body such as the coaxial line 11 with slit of FIG. 1, since it has a duct structure, it is possible to flow dry air into the duct and dry air into the housing if it is a rotating body.
Furthermore, instead of the water repellent coating film / electrode heating h, hot air spraying (3) may be employed.
Further, in the embodiment of the rotating body described later, a waterproof measure (5) may be adopted in which an O-ring is attached to the rotating portion of the housing to make it waterproof.
Moreover, you may employ | adopt the moisture absorption countermeasure (6) of attaching a hygroscopic agent to the main part of a rotary body and a slide body, and removing a water | moisture content. In this case, the hygroscopic agent should be replaced periodically.

[Countermeasures against adhesion and cutting powder]
As a technique for the cleaning robot (4), a technique for keeping the cleanliness of the slide body by running the cleaning robot at a necessary frequency may be adopted.

  The corresponding technologies shown in FIG. 8 have been described above.

The present invention is not limited to the embodiment shown in FIG. 1 described above, but includes modifications and improvements as long as the object of the present invention can be achieved.
Hereinafter, various embodiments different from the embodiment of FIG. 1 will be described.

[Liquid sealing type]
As described above, when water or oil is sandwiched between two flat plates, adhesion (liquid meniscus) occurs. Adhesion (liquid meniscus) occurs regardless of whether the plate surface is hydrophilic or hydrophobic.
However, since adhesion (liquid meniscus) does not occur in water, the coaxial line 11 with a slit in FIG. 1 can be used as an underwater slide rail.
In the case of a rotating system, as shown in FIG. 26, a method of filling the bearing with water or oil may be employed.

FIG. 26 is a diagram illustrating a structure of a power transmission bearing using a liquid-sealed electrode.
FIG. 27 is an enlarged view of a portion constituting the coupling capacitor Cc in the power transmission bearing of FIG.
The electric power transmission bearing in the example of FIG. 26 includes a stator 121 and a rotor 122.
As shown in FIG. 27, the electrode pair 123 constituting one coupling capacitor Cc is configured by pressing two opposing ring-shaped flat plates 123a and 123b with an elastic body (insulating material) such as a foam material. One ring-shaped flat plate 123 a facing the stator 121 is fixed to the stator 121, while the other ring-shaped flat plate 123 b is fixed to the rotor 122.
In addition, as shown in FIG. 27, the electrode pair 124 constituting another one of the coupling capacitances Cc has two ring-shaped flat plates 124a and 124b that are opposed to each other pressed against an elastic body (insulating material) such as a foam material. One ring-shaped flat plate 124 a facing each other is fixed to the stator 121, while the other ring-shaped flat plate 124 b is fixed to the rotor 122.
Between the stator 121 and the rotor 122, water 125 is filled in advance.
The rotor 121 is supported in the radial direction by a plain bearing 126, and the axial direction is supported by an electrode pair 123 and an electrode pair 124.
As described above, when the sliding bearing 126 is filled with the water 125, the power transmission bearing can be used in a high-pressure environment such as deep sea. This is because the water can be prevented from entering from the outside by filling with water 125 in advance. When used in the ocean for a long time, seawater etc. may be mixed, so it is recommended to replace it with fresh water periodically.
Although it can be applied to a bearing, hydrophilic titanium oxide may be mixed and interposed at the contact interface, or in the case of oil, molybdenum disulfide or the like may be mixed. Titanium oxide particles or molybdenum disulfide particles serve as micro rollers.

Note that the electric power transmission bearing can be structured so as not to seal the liquid as compared with the structure of FIG.
In addition to the structure shown in FIG. 26, the power transmission bearing is provided with a bearing that receives stress in the axial direction, and the pair of ring-shaped flat plates (corresponding to the ring-shaped flat plates 124a and 124b in FIG. A method in which no force other than the force necessary for forming the gap is also possible. However, vibration force for reducing frictional force may be applied.

[combination]
For example, as shown in the first line of FIG. 9, an embodiment of a new bearing structure of a rotating body to which the corresponding technology of the solid lubricant a is applied can also be realized.
FIG. 28 is a cross-sectional view of a power transmission bearing to which the corresponding technology of the solid lubricant a is applied as another embodiment of the power transmission system to which the present invention is applied.
As shown in FIG. 28, the power transmission bearing 130 is attached to a machine body 131 having a rotating shaft.
As a circuit of the electric field coupling power transmission technology, a power transmission unit 141 is provided outside, a power reception unit 142 is provided inside the power transmission bearing 130, and power is supplied to a load on the rotation shaft in the machine body via the rotation shaft. It is made to be supplied.
In order to use the power transmission bearing 130 as an attachment to the rotary shaft 146 coming out of the machine main body 131, the rotary shaft 146 is fixed by a bearing (not shown) attached to the machine main body 131.
A member 145a is provided between the first rotating shaft 144a and the second rotating shaft 144b.
A member 145b is provided between the second rotating shaft 144b and the pipe 147 that joins the second rotating shaft 144b and the rotating shaft 146.
Each of the member 145a and the member 145b is formed of a material having flexibility, insulating properties, and strength that can withstand a bending force around the rotation axis.
As a result, the first rotating shaft 144a and the second rotating shaft 144b can cope with a rotating shaft slightly shifted from the rotating shaft 146 of the rotating bearing.
Furthermore, the bearing 143a and the first rotating shaft 144a form a junction capacitance Cc in the electric field coupled power transmission technique.
The bearing 143b and the second rotating shaft 144b form a junction capacitance Cc in the electric field coupled power transmission technique.
Therefore, a solid lubricant may be provided for the bearing 143a and the bearing 143b. A bearing that receives the load of the rotating shaft 146 is not shown, and the bearings 143a and 143b function as power transmission contacts or joint capacities.

FIG. 29 is a cross-sectional view of a power transmission bearing to which a corresponding technique of minimum gap maintenance b and c is applied as still another embodiment of the power transmission system to which the present invention is applied.
The basic configuration of the power transmission bearing 130 of the example of FIG. 29 is the same as that of the example of FIG. 28 (and therefore will not be described), but DLC is used as an electrode pair for forming the junction capacitance Cc in the electric field coupling power transmission technique. An attached ultrathin metal pair 150a, 150b is provided.
In this ultrathin metal pair with DLC 150a, 150b, a minimum gap is formed in accordance with the principle described above.

  Further, although not shown in the drawings, the corresponding techniques of the solid lubricant a and the corresponding techniques of the minimum gap maintenance b and c may be applied in combination with the examples of FIGS.

FIG. 30 is a perspective view showing an outline of a basic configuration of a slip ring as still another embodiment of the power transmission system to which the present invention is applied.
In the slip ring of the example of FIG. 30, the current collecting ring 162 is connected to the rotating shaft 161 via the insulator 163.

Here, the current collecting ring 162 and the filament 164 are made of bare metal and are used in contact with each other. For this reason, there are the following problems.
That is, the first problem is that the amount of transmitted power is limited because the current density at the contact point between the current collecting ring 162 and the filament 164 is high. In particular, local heating occurs when used in a fixed state.
The second problem is that the conductive metals of the current collecting ring 162 and the filament 164 rub against each other, so that conductive cutting powder is generated and short-circuited, so that maintenance is indispensable.
The third problem is that the metal of the current collecting ring 162 and the filament 164 is exposed, so that it is vulnerable to acids and alkalis. When water is mixed in, the filament 164 floats and power transmission becomes unstable.
A fourth problem is that when the rotational speed is increased, air enters between the filament 164 and the current collecting ring 162, and power transmission becomes unstable. If the pressure is increased, wear will progress.
The fifth problem is that it is difficult to provide a high-speed communication function in terms of the current collecting ring 162 and the filament 164.
However, in order to solve these problems, a solution to the problem of tribology in the junction capacitance Cc can be taken in terms of a contact type. That is, the above-described corresponding techniques of FIGS. 8 and 9 can be applied.

11 ... Coaxial line with slit 21 ... Connector 22 ... External conductor 23 ... Internal conductor 31 ... Connector external electrode 32 ... Connector internal electrode 41 ... Power receiving unit 51 ... Power transmission Part

Claims (1)

A slide-type or rotary-type power transmission system that transmits electric power using electric field coupled power transmission technology,
An electrode pair for forming a coupling capacitance in the electric field coupled power transmission technology, the electrode pair having a relatively moving electrode,
Generated when the electrodes move relative to each other due to a pressing pressure or a force based on the pressing force having at least a component in a direction substantially perpendicular to the moving direction of the electrodes between the electrodes of the electrode pair. A gap with a minimum gap caused by a repulsive force is provided, or a gap with a minimum gap is provided while reducing the frictional force during movement,
Electric power transmission system.

Images