JP2015035346A - Combination of slide contact members - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve further reduction in friction coefficient.SOLUTION: A combination of slide contact members include at least one first slide contact member and at least one second slide contact member as a mating member of the first slide contact member, which are brought into slide contact each other relatively. At least a sliding surface of the first slide contact member comprises a first slide member including a conductive hard carbon-containing material that contains conductive hard carbon. At least a sliding surface of the second slide contact member comprises a second slide member including a first conductive material having lower oxide generation energy than the conductive hard carbon.

Description

  The present invention relates to a combination of sliding contact members. More specifically, the present invention includes at least one first sliding contact member that is relatively slidingly contacted, and at least one second sliding contact member that is a counterpart member of the first sliding contact member. The present invention relates to a combination of sliding contact members provided.

  Conventionally, there has been proposed a conductive member that has good wear resistance and oxidation resistance and is suitable for contact between conductive members (see Patent Document 1). The conductive member constituting the sliding contact by the brush feeding electrode is composed of an elastic wire material that is bundled in a brush shape and covered with a conductive DLC supported by the conductive material, and a conductive boron-doped material formed on the conductive material. And a diamond film.

JP 2002-025346 A

  However, in the conductive member described in Patent Document 1, since the conductive DLC and the conductive boron-doped diamond are combined and slid, there is a problem that the conformability is poor and the friction coefficient is high. .

  The present invention has been made in view of such problems of the prior art. And this invention aims at providing the combination of the sliding contact member which can implement | achieve further reduction of a friction coefficient.

  The inventors of the present invention have made extensive studies in order to achieve the above object. As a result, at least one predetermined first sliding contact member that is relatively in sliding contact, and at least one predetermined second sliding contact member that is a counterpart member of the first sliding contact member, It has been found that the above object can be achieved by using the provided structure, and the present invention has been completed.

  That is, the combination of the sliding contact members of the present invention has at least one first sliding contact member that is relatively slidingly contacted and at least one second sliding member that is a counterpart member of the first sliding contact member. And a contact member. And at least the sliding surface of the first sliding contact member is constituted by the first sliding member containing the conductive hard carbon-containing material containing conductive hard carbon, and at least the sliding of the second sliding contact member The surface is constituted by a second sliding member including a first conductive material whose oxide generation energy is smaller than that of conductive hard carbon.

  According to the present invention, at least one first sliding member constituted by a first sliding member that includes a conductive hard carbon-containing material that has a relatively hard sliding contact and at least a sliding surface contains conductive hard carbon. The contact member is a counterpart member of the first sliding contact member, and at least the sliding surface is configured by a second sliding member including a first conductive material whose oxide generation energy is smaller than that of conductive hard carbon. It was set as the structure provided with the at least 1 2nd sliding contact member. As a result, the friction coefficient can be further reduced.

FIG. 1 is a cross-sectional view schematically showing an example of a combination of sliding contact members according to the first embodiment of the present invention. FIG. 2 is a cross-sectional view schematically showing another example of the combination of sliding contact members according to the first embodiment of the present invention. FIG. 3 is a cross-sectional view schematically showing an example of a combination of sliding contact members according to the second embodiment of the present invention. FIG. 4 is a cross-sectional view schematically showing an example of a combination of sliding contact members according to the third embodiment of the present invention. FIG. 5 is a cross-sectional view schematically showing an example of a combination of sliding contact members according to the fourth embodiment of the present invention. FIG. 6 is an explanatory view showing an example of a manufacturing method of the first sliding contact member applied to the combination of sliding contact members according to the fourth embodiment of the present invention. FIG. 7 is a cross-sectional view schematically showing an example of a combination of sliding contact members according to the fifth embodiment of the present invention. FIG. 8 is a cross-sectional view schematically showing an example of a combination of sliding contact members according to the sixth embodiment of the present invention. FIG. 9 is a cross-sectional view schematically showing an example of a combination of sliding contact members according to the seventh embodiment of the present invention. FIG. 10 is a cross-sectional view illustrating a DC motor to which a combination of sliding contact members according to an embodiment of the present invention is applied. FIG. 11 is a schematic diagram showing the outline of the ball-on-disk test. FIG. 12 is a graph showing the relationship between the current and the coefficient of friction in Example 1. FIG. 13 is a graph showing the content of copper oxide (II) (CuO) and copper oxide (I) (Cu ₂ O) measured using the combination of sliding contact members of Example 1. FIG. 14 is a graph showing the content of copper oxide (II) (CuO) and copper oxide (I) (Cu ₂ O) measured using the combination of sliding contact members of Comparative Example 1. FIG. 15 is a graph showing the relationship between the current and the friction coefficient in Example 2. FIG. 16 is a graph showing the relationship between the current and the friction coefficient in Example 3. FIG. 17 is a graph showing the relationship between the current and the coefficient of friction in Comparative Example 2. FIG. 18 is a graph showing the relationship between the current and the coefficient of friction in Example 1 and Example 4.

  Hereinafter, a combination of sliding contact members according to an embodiment of the present invention will be described in detail with reference to the drawings. In addition, the dimension ratio of drawing is exaggerated on account of description, and may differ from an actual ratio.

(First embodiment)
First, the combination of sliding contact members according to the first embodiment will be described in detail. FIG. 1 is a cross-sectional view schematically showing an example of a combination of sliding contact members according to the first embodiment. As shown in FIG. 1, the sliding contact member combination 1 </ b> A of this example includes at least one first sliding contact member 10 and at least one second sliding member that is a counterpart member of the first sliding contact member 10. The contact member 20 is provided. The first sliding contact member 10 and the second sliding point member 20 ensure energization while relatively slidingly contacting each other. And by the 1st sliding member 11 in which the at least sliding surface 10a of the 1st sliding contact member 10 contains the electroconductive hard carbon containing material (not shown) containing electroconductive hard carbon (not shown). The second sliding member 21 includes a first conductive material (not shown) in which at least the sliding surface 20a of the second sliding contact member 20 has an oxide generation energy smaller than that of conductive hard carbon. It is configured. In this example, the first sliding contact member 10 itself is the first sliding member 11, and the second sliding contact member 20 itself is the second sliding member 21.

  Here, in the present invention, the “first sliding member” means that the area ratio of the conductive hard carbon on the sliding surface is 50 area% or more, preferably 50 volume% of the conductive hard carbon. The term “second sliding member” means that the area ratio of the first conductive material on the sliding surface is 50% by area or more, preferably 50 volumes of the first conductive material. % Or more is meant.

Although not particularly limited, the first sliding member preferably has a specific resistance of 1 × 10 ⁻¹ Ω · cm or less from the viewpoint of preventing loss due to heat generation. For example, when applied to a DC motor, loss due to heat generation is further reduced, and the efficiency of the DC motor can be further improved. Moreover, since the amount of wear is reduced, the life of the DC motor can be extended.

  Furthermore, although not particularly limited, the surface roughness of the sliding surface of the first sliding contact member is Ra 0.1 or less, which is aggressive to the second sliding contact member which is the counterpart member. Is preferable from the viewpoint that the friction coefficient can be further reduced. For example, when applied to a DC motor, drag loss is further reduced, and the efficiency of the DC motor can be further improved. Moreover, since the amount of wear is reduced, the life of the DC motor can be extended.

  Further, in the present invention, the “conductive hard carbon-containing material” is not limited to a composite containing conductive hard carbon and a catalyst component capable of joining the conductive hard carbon, but only composed of conductive hard carbon. Must be interpreted to include.

  In addition, as a conductive hard carbon, a conductive diamond, conductive diamond-like carbon, etc. can be mentioned as a suitable example from a viewpoint of the reduction of the friction coefficient by energization sliding, and an improvement in abrasion resistance, for example. Here, as the conductive diamond, conventionally known ones such as boron-doped diamond can be applied. In addition, examples of conductive diamond-like carbon include ta-C structure diamond-like carbon (so-called hydrogen-free diamond-like carbon), aC: H structure-like diamond-like carbon (so-called hydrogen-containing diamond-like carbon), and metal element doping. Conventionally known materials such as diamond-like carbon can be applied. Among these, conductive diamond is particularly preferable from the viewpoint of high heat dissipation.

  Examples of suitable catalyst components include cobalt (Co), silicon (Si), nickel (Ni), titanium (Ti), boron (B), and the like. A combination of more than one species can be applied. These catalyst components are necessary components for obtaining a granulated body or a sintered body (bulk body) using conductive diamond particles.

  Further, although not particularly limited, the hardness of the conductive hard carbon or the conductive hard carbon-containing material is preferably Hv1000 or more from the viewpoint of improving the wear resistance. For example, when applied to a DC motor, the amount of wear is reduced, so that the life of the DC motor can be extended.

Further, in the present invention, “a first conductive material having an oxide generation energy smaller than that of conductive hard carbon” can be defined using, for example, an Ellingham diagram of an oxide. That is, in the Ellingham diagram, a metal that is more easily oxidized than carbon may be selected. For example, copper (Cu), tin (Sn), nickel (Ni), cobalt (Co), iron (Fe), and the like are preferable examples. These can be applied singly or in combination of two or more. Among these, copper is more preferable. In addition, it is preferable that the first conductive material includes, for example, copper or a copper alloy and another conductive material such as a carbon material such as graphite from the viewpoint of further reducing the friction coefficient. . Furthermore, the first conductive material contains, for example, copper, and the friction coefficient is further increased by the configuration in which copper (I) (Cu ₂ O) is formed on at least the sliding surface of the second sliding contact member. It is preferable from the viewpoint that it can be reduced.

  Further, FIG. 2 is a cross-sectional view schematically showing another example of the combination of sliding contact members according to the first embodiment. As shown in FIG. 2, in the sliding contact member combination 1 </ b> B of this example, the first sliding contact member 10 is formed on the support 19 and at least the sliding surface 10 a side of the first sliding contact member 10. And a first sliding member 11 containing a conductive hard carbon-containing material (not shown) containing conductive hard carbon (not shown), and the second sliding contact member 20. However, the first conductive material (not shown) having lower oxide generation energy than the support 29 and the conductive hard carbon (not shown) formed on at least the sliding surface 20a side of the second sliding contact member 20. 2) is different from the combination of the sliding contact members in the above-described example.

  In the present example, the thickness of the first sliding member 11 is preferably 0.01 mm or more, and more preferably 0.3 mm or more. In addition, what is necessary is just to adjust the thickness of the 2nd sliding member 21 suitably according to a structural component in this example.

  As described above, in the present embodiment, at least the sliding surface of the first sliding contact member is constituted by the first sliding member including the conductive hard carbon-containing material containing conductive hard carbon, and Further, since at least the sliding surface of the second sliding contact member is constituted by the second sliding member including the first conductive material whose oxide generation energy is smaller than that of the conductive hard carbon, the friction coefficient is further increased. Reduction can be realized. Moreover, these are applicable to the combination of the brush and commutator (commutator) of a DC motor, for example. In this case, drag loss is reduced and the efficiency of the DC motor can be improved. Further, the amount of wear is reduced, and the life of the DC motor can be extended. Further, in the other example described above, the material constituting the support can be selected without considering the frictional resistance, and therefore may be selected in consideration of heat dissipation characteristics, conductivity, and the like. When applied to a combination of a brush and a commutator (commutator) of a DC motor, the efficiency of the DC motor can be further improved by selecting the material of the support in consideration of conductivity. Such a DC motor can be adapted to the high output and large current required for driving an electric vehicle (EV) or the like.

  At present, we believe that the effect is obtained by the following mechanism. However, it goes without saying that even if the effect is obtained without using the following mechanism, it is included in the scope of the present invention.

  When the first sliding contact member and the second sliding contact member are slid while being energized, the first conductive material of the second sliding member in the second sliding contact member becomes the first conductive member in the first sliding contact member. This is considered to be because an oxide film showing a low coefficient of friction is formed by being reduced by the conductive hard carbon of the sliding member. For example, a phenomenon in which copper oxide (II) becomes copper oxide (I) when the first conductive material is copper is a typical example, but is not limited thereto.

  Although not shown in the drawings, in the present embodiment, the first sliding contact member and the second sliding contact member shown in each of the above examples may be combined differently. Moreover, although not shown in figure, the 1st sliding member and the 2nd sliding member may have the laminated structure and inclination structure from which the kind and density | concentration of the component differed. Further, although not shown, when the potential relationship in the circuit of the first sliding contact member and the second sliding contact member does not reverse, the first sliding contact member is used on the low potential side, and the second sliding contact member is used. Is preferably used on the high potential side from the viewpoint of further reducing the friction coefficient.

  As the second sliding contact member described above, a member made of the first conductive material or a member containing the first conductive material itself may be applied, but these coatings are applied to at least the sliding surface of the support. What was formed can also be applied. These coatings can be formed by a conventionally known method.

  In addition, as the first sliding contact member described above, one made of a conductive hard carbon-containing material or one containing a conductive hard carbon-containing material itself may be applied, but at least a sliding surface in the support. A film having these films formed on the surface can also be applied. In detail, these may be formed by a vapor phase growth method such as a CVD (Chemical Vapor Deposition) method or a PVD (Physical Vapor Deposition) method, a cold spray method such as a powder deposition method, or a sintering method. it can.

  The CVD method and the PVD method are suitable for forming a film made of a deposit made of a conductive hard carbon-containing material or a film made of a deposited material containing a conductive hard carbon-containing material on the surface to be a sliding surface of the support. ing. Moreover, when forming a film by CVD method or PVD method, from the viewpoint of peeling resistance, the film thickness is made thinner than when forming a film made of green compact by cold spray method or sintering method. It is preferable.

  In the powder deposition method and the sintering method, a film made of a green compact made of a conductive hard carbon-containing material or a film made of a green compact containing a conductive hard carbon-containing material is applied to the surface that becomes the sliding surface of the support. Suitable for forming. The powder deposition method and the sintering method are also suitable for forming a first sliding contact member made of a green compact containing a conductive hard carbon-containing material or a conductive hard carbon-containing material. Furthermore, when forming a film by a cold spray method or a sintering method, from the viewpoint of raw material size, it is possible to increase the film thickness as compared with the case where a film made of a deposit is formed by a CVD method or a PVD method. preferable.

(Second Embodiment)
Next, a combination of sliding contact members according to the second embodiment will be described in detail. In addition, about the thing equivalent to what was demonstrated in said embodiment, the code | symbol same as them is attached | subjected and description is abbreviate | omitted. Further, the configuration example described without being illustrated may be applied as it is or appropriately modified as long as it is applicable to the present embodiment, and the description thereof is omitted. FIG. 3 is a cross-sectional view schematically showing an example of a combination of sliding contact members according to the second embodiment. As shown in FIG. 3, in the sliding contact member combination 1 </ b> C of this example, at least the sliding surface 10 a of the first sliding contact member 10 has a conductive hard carbon-containing material (not shown) and a second conductive material. (It is not shown.) The point comprised by the 1st sliding member 12 containing is different from the combination of the sliding contact member which concerns on 1st Embodiment mentioned above.

  In the present embodiment, the thickness of the first sliding member 12 is preferably 0.01 mm or more, and more preferably 0.3 mm or more.

  Here, in the present invention, the “second conductive material” is not particularly limited as long as it has conductivity. For example, a metal material having higher conductivity than the conductive hard carbon-containing material. Is preferable from the viewpoint of conductivity. Specifically, silver (Ag), copper (Cu), gold (Au), molybdenum (Mo), cobalt (Co), etc. can be mentioned, and these can be used alone or in combination of two or more. Can be applied.

  In the present embodiment, at least the sliding surface of the first sliding contact member is constituted by a first sliding member including a conductive hard carbon-containing material containing conductive hard carbon and a second conductive material, In addition, since at least the sliding surface of the second sliding contact member is constituted by the second sliding member including the first conductive material whose oxide generation energy is smaller than that of the conductive hard carbon, the friction coefficient is further increased. Can be achieved. Moreover, these are applicable to the combination of the brush and commutator (commutator) of a DC motor, for example. In this case, drag loss and electrical resistance loss are reduced, and the efficiency of the DC motor can be further improved. Further, the amount of wear is reduced, and the life of the DC motor can be extended.

  Although not shown, also in this embodiment, the first sliding contact member itself may be the first sliding member, and the second sliding contact member includes the support and the second sliding contact. You may be comprised by the 1st sliding member 11 containing the electroconductive hard carbon containing material formed in the sliding surface side at least of the member. Further, although not shown, the first sliding member and the second sliding member may have a laminated structure or an inclined structure in which the types and concentrations of the constituent components are different. Although not shown, when the potential relationship in the circuit of the first sliding contact member and the second sliding contact member is not reversed, the first sliding contact member is used on the low potential side, and the second sliding contact member is used. Is preferably used on the high potential side from the viewpoint of further reducing the friction coefficient.

  Moreover, as the first sliding contact member described above, a film made of a green compact or a deposit formed by the above-described CVD method, PVD method, powder deposition method, sintering method or the like can be applied. .

(Third embodiment)
Next, a combination of sliding contact members according to the third embodiment will be described in detail. In addition, about the thing equivalent to what was demonstrated in said embodiment, the code | symbol same as them is attached | subjected and description is abbreviate | omitted. Further, the configuration example described without being illustrated may be applied as it is or appropriately modified as long as it is applicable to the present embodiment, and the description thereof is omitted. FIG. 4 is a cross-sectional view schematically showing an example of a combination of sliding contact members according to the third embodiment. As shown in FIG. 4, the sliding contact member combination 1D of the present example includes a conductive hard carbon-containing material 13 in which at least the sliding surface 10a of the first sliding contact member 10 is in the form of particles and the second conductive in the form of particles. The point comprised by the 1st sliding member 12 which consists of a green compact containing the material 15 differs from the combination of the sliding contact member which concerns on the 1st or 2nd embodiment mentioned above.

  In the present embodiment, the thickness of the first sliding member 12 is preferably 0.01 mm or more, and more preferably 0.3 mm or more.

  In the present embodiment, the particle size of the conductive hard carbon-containing material 13 is preferably 0.002 to 0.05 mm in average particle size, and more preferably 0.005 to 0.01 mm. In the present embodiment, the particle size of the second conductive material 15 is preferably 0.05 mm or less, and more preferably 0.01 mm or less, in terms of average particle size.

  In the present invention, the “particle diameter” means a conductive hard carbon-containing material (or conductive carbon) that is observed using an observation means such as a scanning electron microscope (SEM) or a transmission electron microscope (TEM). It means the maximum distance among the distances between any two points on the contour line of the (observation surface) such as particles and second conductive material particles.

  In the present invention, the value of the “average particle diameter” is the value of particles observed in several to several tens of fields using an observation means such as a scanning electron microscope (SEM) or a transmission electron microscope (TEM). The value calculated as the average value of the particle diameter shall be adopted. The particle diameters and average particle diameters of other components can be defined in the same manner.

  However, it is not limited to such a range at all, and it goes without saying that it may be outside this range as long as the effects of the present embodiment can be expressed effectively.

  In the present embodiment, at least the sliding surface of the first sliding contact member is made of a green compact including a particulate conductive hard carbon-containing material containing conductive hard carbon and a particulate second conductive material. The second sliding member is composed of the first sliding member, and at least the sliding surface of the second sliding contact member includes the first conductive material that has lower oxide generation energy than the conductive hard carbon. Therefore, the friction coefficient can be further reduced. Moreover, these are applicable to the combination of the brush and commutator (commutator) of a DC motor, for example. In this case, drag loss and electrical resistance loss are reduced, and the efficiency of the DC motor can be further improved. Further, the amount of wear is reduced, and the life of the DC motor can be extended.

  Although not shown, also in this embodiment, the first sliding contact member itself may be the first sliding member, and the second sliding contact member includes the support and the second sliding contact. You may be comprised by the 1st sliding member 11 containing the electroconductive hard carbon containing material formed in the sliding surface side at least of the member. Further, although not shown, the first sliding member and the second sliding member may have a laminated structure or an inclined structure in which the types and concentrations of the constituent components are different. Although not shown, when the potential relationship in the circuit of the first sliding contact member and the second sliding contact member is not reversed, the first sliding contact member is used on the low potential side, and the second sliding contact member is used. Is preferably used on the high potential side from the viewpoint of further reducing the friction coefficient.

  Moreover, as the first sliding contact member described above, it is preferable to apply a film made of a green compact formed by a method such as the above-described powder deposition method or sintering method.

(Fourth embodiment)
Next, a combination of sliding contact members according to the fourth embodiment will be described in detail. In addition, about the thing equivalent to what was demonstrated in said embodiment, the code | symbol same as them is attached | subjected and description is abbreviate | omitted. Further, the configuration example described without being illustrated may be applied as it is or appropriately modified as long as it is applicable to the present embodiment, and the description thereof is omitted. FIG. 5 is a cross-sectional view schematically showing an example of a combination of sliding contact members according to the fourth embodiment. As shown in FIG. 5, the combination 1E of sliding contact members of this example includes a plurality of particles in which at least the sliding surface 10a of the first sliding contact member 10 is made of a conductive hard carbon-containing material 13, and the conductive The point which is comprised by the 1st sliding member 12 which consists of a green compact containing the 2nd electrically conductive material 15 which bind | concludes hard carbon containing material particles is based on the slide which concerns on the 1st-3rd embodiment mentioned above. It differs from the combination of moving contact members.

  In the present embodiment, the thickness of the first sliding member 12 is preferably 0.01 mm or more, and more preferably 0.3 mm or more.

  In the present embodiment, the particle size of the conductive hard carbon-containing material 13 is preferably 0.002 to 0.05 mm in average particle size, and more preferably 0.005 to 0.01 mm.

  In this embodiment, at least the sliding surface of the first sliding contact member binds the plurality of particles made of a conductive hard carbon-containing material containing conductive hard carbon and the conductive hard carbon-containing material particles. The first sliding member is made of a green compact including the second conductive material, and at least the sliding surface of the second sliding contact member has a smaller oxide generation energy than the conductive hard carbon. Since the second sliding member including one conductive material is used, the friction coefficient can be further reduced. Further, when formed by a powder deposition method as will be described in detail later, the formation of pores is suppressed by the second conductive material that binds the conductive hard carbon-containing material particles to each other, and a conductive path can be reliably formed. Therefore, compared with the case of forming by a sintering method, it is easy to reduce the electric resistance while realizing the reduction of the friction coefficient. Moreover, these are applicable to the combination of the brush and commutator (commutator) of a DC motor, for example. In this case, drag loss and electrical resistance loss are reduced, and the efficiency of the DC motor can be further improved. Further, the amount of wear is reduced, and the life of the DC motor can be extended.

  Although not shown, also in this embodiment, the first sliding contact member itself may be the first sliding member, and the second sliding contact member includes the support and the second sliding contact. You may be comprised with the 1st sliding member containing the electroconductive hard carbon containing material formed in the sliding surface side at least of the member. Further, although not shown, the first sliding member and the second sliding member may have a laminated structure or an inclined structure in which the types and concentrations of the constituent components are different. Although not shown, when the potential relationship in the circuit of the first sliding contact member and the second sliding contact member is not reversed, the first sliding contact member is used on the low potential side, and the second sliding contact member is used. Is preferably used on the high potential side from the viewpoint of further reducing the friction coefficient.

  In addition, as the first sliding contact member described above, a coating made of a green compact formed by a method such as the above-described powder deposition method or sintering method can be applied, but it is particularly formed by the powder deposition method. It is preferable to apply the above.

  FIG. 6 is an explanatory view showing an example of a manufacturing method of the first sliding contact member applied to the present embodiment. Here, the first sliding member 12 is formed by a powder deposition method.

  In the powder deposition method, a jet nozzle N, a heater H for heating helium gas, and an apparatus having a feeder F for supplying a powder material are used. To do.

  That is, in order to manufacture the first sliding contact member 10, a conductive diamond that is an example of conductive hard carbon or a granulated conductive diamond-containing material and a copper powder material that is an example of a second conductive material are used. It is an example of the 2nd electrically conductive material which sprays on the upper surface of the support body 19, and bind | concludes several particle | grains which consist of electroconductive diamond or the granulated electroconductive diamond containing material, and electroconductive hard carbon containing material particles. It forms in the 1st sliding member 12 which consists of a green compact containing copper.

  Thus, the 1st sliding contact member 10 which concerns on this embodiment can be manufactured easily and cheaply by utilizing the powder deposition method.

(Fifth embodiment)
Next, a combination of sliding contact members according to the fifth embodiment will be described in detail. In addition, about the thing equivalent to what was demonstrated in said embodiment, the code | symbol same as them is attached | subjected and description is abbreviate | omitted. Further, the configuration example described without being illustrated may be applied as it is or appropriately modified as long as it is applicable to the present embodiment, and the description thereof is omitted. FIG. 7 is a cross-sectional view schematically showing an example of a combination of sliding contact members according to the fifth embodiment. As shown in FIG. 7, in the combination 1F of the sliding contact member of this example, a plurality of particles in which at least the sliding surface 10a of the first sliding contact member 10 is made of the conductive hard carbon-containing material 13 are joined together. The first sliding member 12 is made of a green compact including a porous body 17 having a structure and a second conductive material 15 included in a gap between the porous body 17. To a combination of sliding contact members according to the fourth embodiment.

  In the present embodiment, the thickness of the first sliding member 12 is preferably 0.01 mm or more, and more preferably 0.3 mm or more.

  In the present embodiment, the particle size of the conductive hard carbon-containing material 13 is preferably 0.002 to 0.05 mm in average particle size, and more preferably 0.005 to 0.01 mm.

  In the present embodiment, at least the sliding surface of the first sliding contact member has a porous body having a structure in which a plurality of particles made of a conductive hard carbon-containing material containing conductive hard carbon are joined, The first sliding member is made of a green compact including a second conductive material contained in the gap between the porous bodies, and at least the sliding surface of the second sliding contact member is made of conductive hard carbon. Further, since the second sliding member including the first conductive material having a small oxide generation energy is used, the friction coefficient can be further reduced. Moreover, these are applicable to the combination of the brush and commutator (commutator) of a DC motor, for example. In this case, drag loss and electrical resistance loss are reduced, and the efficiency of the DC motor can be further improved. Further, the amount of wear is reduced, and the life of the DC motor can be extended.

  Although not shown, also in this embodiment, the first sliding contact member itself may be the first sliding member, and the second sliding contact member includes the support and the second sliding contact. You may be comprised by the 1st sliding member 11 containing the electroconductive hard carbon containing material formed in the sliding surface side at least of the member. Further, although not shown, the first sliding member and the second sliding member may have a laminated structure or an inclined structure in which the types and concentrations of the constituent components are different. Although not shown, when the potential relationship in the circuit of the first sliding contact member and the second sliding contact member is not reversed, the first sliding contact member is used on the low potential side, and the second sliding contact member is used. Is preferably used on the high potential side from the viewpoint of further reducing the friction coefficient.

  In addition, as the first sliding contact member described above, a film made of a green compact formed by a method such as the above-described powder deposition method or sintering method can be applied, but it is particularly formed by a sintering method. It is preferable to apply one.

(Sixth embodiment)
Next, a combination of sliding contact members according to the sixth embodiment will be described in detail. In addition, about the thing equivalent to what was demonstrated in said embodiment, the code | symbol same as them is attached | subjected and description is abbreviate | omitted. Further, the configuration example described without being illustrated may be applied as it is or appropriately modified as long as it is applicable to the present embodiment, and the description thereof is omitted. FIG. 8 is a cross-sectional view schematically showing an example of a combination of sliding contact members according to the sixth embodiment. As shown in FIG. 8, in the sliding contact member combination 1G of this example, at least the sliding surface 10a of the first sliding contact member 10 includes the conductive hard carbon-containing material 13 and the second conductive material 15. The point comprised by the 1st sliding member 12 which consists of deposits differs from the combination of the sliding contact member which concerns on the 1st-5th embodiment mentioned above. In this example, the conductive hard carbon-containing material and the second conductive material each constitute a polycrystal, but the present embodiment is not limited to this. For example, the structure by which the 2nd electrically conductive material was doped to the polycrystal body of an electroconductive hard carbon containing material may be sufficient.

  In the present embodiment, the thickness of the first sliding member 12 is preferably 0.01 mm or more, and more preferably 0.3 mm or more.

  In the present embodiment, the particle diameter of the conductive hard carbon-containing material 13 is preferably 0.002 to 0.05 mm in average particle diameter, and more preferably 0.005 to 0.01 mm. . In the present embodiment, the particle size of the second conductive material 15 is preferably 0.05 mm or less, and more preferably 0.01 mm or less, in terms of average particle size.

  In this embodiment, at least the sliding surface of the first sliding contact member includes a conductive hard carbon-containing material containing conductive hard carbon and a first sliding member made of a deposit including a second conductive material. Because it is configured, and at least the sliding surface of the second sliding contact member is constituted by the second sliding member including the first conductive material whose oxide generation energy is smaller than that of the conductive hard carbon. Further reduction of the friction coefficient can be realized. Moreover, these are applicable to the combination of the brush and commutator (commutator) of a DC motor, for example. In this case, drag loss and electrical resistance loss are reduced, and the efficiency of the DC motor can be further improved. Further, the amount of wear is reduced, and the life of the DC motor can be extended.

  Although not shown, in the present embodiment, the second sliding contact member includes a support and a conductive hard carbon-containing material formed on at least the sliding surface side of the second sliding contact member. The sliding member 11 may be used. Moreover, although not shown in figure, the 1st sliding member and the 2nd sliding member may have the laminated structure and inclination structure from which the kind and density | concentration of the component differed. Further, although not shown, when the potential relationship in the circuit of the first sliding contact member and the second sliding contact member does not reverse, the first sliding contact member is used on the low potential side, and the second sliding contact member is used. Is preferably used on the high potential side from the viewpoint of further reducing the friction coefficient.

  Moreover, it is preferable to apply the film which consists of a deposit formed by methods, such as the CVD method mentioned above and PVD method, as a 1st sliding contact member mentioned above.

(Seventh embodiment)
Next, a combination of sliding contact members according to the seventh embodiment will be described in detail. In addition, about the thing equivalent to what was demonstrated in said embodiment, the code | symbol same as them is attached | subjected and description is abbreviate | omitted. Further, the configuration example described without being illustrated may be applied as it is or appropriately modified as long as it is applicable to the present embodiment, and the description thereof is omitted. FIG. 9 is a cross-sectional view schematically showing an example of a combination of sliding contact members according to the seventh embodiment. As shown in FIG. 9, the sliding contact member combination 1 </ b> H of the present example includes the first sliding contact member 10, the first sliding contact member 10 comprising at least a sliding surface 10 a made of a conductive hard carbon-containing material 13 alone. The point comprised by the moving member 11 is different from the combination of the sliding contact member which concerns on the 1st-6th embodiment mentioned above. In addition, the deposit body in this example is comprised with the polycrystal.

  In the present embodiment, the thickness of the first sliding member 11 is preferably 0.01 mm or more, and more preferably 0.3 mm or more.

  In the present embodiment, the particle diameter of the conductive hard carbon-containing material 13 is preferably 0.002 to 0.05 mm in average particle diameter, and more preferably 0.005 to 0.01 mm. .

  In this embodiment, at least the sliding surface of the first sliding contact member is constituted by a first sliding member made of a deposit made of a conductive hard carbon-containing material containing conductive hard carbon, and Since at least the sliding surface of the second sliding contact member is constituted by the second sliding member including the first conductive material whose oxide generation energy is smaller than that of the conductive hard carbon, the friction coefficient is further reduced. Can be realized. Moreover, these are applicable to the combination of the brush and commutator (commutator) of a DC motor, for example. In this case, drag loss is reduced and the efficiency of the DC motor can be further improved. Further, the amount of wear is reduced, and the life of the DC motor can be extended.

  Although not shown, in the present embodiment, the second sliding contact member includes a support and a conductive hard carbon-containing material formed on at least the sliding surface side of the second sliding contact member. The sliding member 11 may be used. Moreover, although not shown in figure, the 1st sliding member and the 2nd sliding member may have the laminated structure and inclination structure from which the kind and density | concentration of the component differed. Further, although not shown, when the potential relationship in the circuit of the first sliding contact member and the second sliding contact member does not reverse, the first sliding contact member is used on the low potential side, and the second sliding contact member is used. Is preferably used on the high potential side from the viewpoint of further reducing the friction coefficient.

  Moreover, it is preferable to apply the film which consists of a deposit formed by methods, such as the CVD method mentioned above and PVD method, as a 1st sliding contact member mentioned above.

  FIG. 10 is a cross-sectional view illustrating a DC motor to which a combination of sliding contact members according to an embodiment of the present invention is applied. The DC motor M includes an armature 53 rotatably held by a bearing 52 and a magnet 55 that opposes the coil 54 of the armature 53 inside the motor case 51. A plurality of brushes 56 are provided on the motor case 51 side. Each brush 56 is energized while being in sliding contact with a commutator (commutator) 57 provided coaxially with the armature 53. Note that the DC generator has the same configuration.

  The combination of the sliding contact members described in the above embodiments constitutes a combination of the brush 56 and the commutator 57 in the DC motor shown in FIG. Thereby, the lifetime improvement and performance improvement of the component of a DC motor are realizable.

Example 1
A first sliding contact member made of a conductive diamond-containing material (average particle diameter: 0.005 mm) as a conductive hard carbon-containing material is formed by a sintering method, and the first sliding contact member used in this example is formed. Obtained. Moreover, the ball-shaped copper member was used as the second sliding contact member used in this example.

(Example 2)
A first sliding contact member made of a conductive diamond-containing material (average particle diameter: 0.005 mm) as a conductive hard carbon-containing material is formed by a sintering method, and the first sliding contact member used in this example is formed. Obtained. A ball-like copper-containing graphite member was used as the second sliding contact member used in this example.

Example 3
A first sliding member made of conductive diamond-like carbon (DLC) as a conductive hard carbon-containing material was formed by a CVD method to obtain a first sliding contact member used in this example. Moreover, the ball-shaped copper member was used as the second sliding contact member used in this example.

Example 4
The same first sliding contact member and second sliding point member as in Example 1 were used.

(Comparative Example 1)
The disk-shaped graphite member was used as the first sliding contact member used in this example. Moreover, the ball-shaped copper member was used as the second sliding contact member used in this example.

(Comparative Example 2)
A first sliding contact member made of a conductive diamond-containing material (average particle diameter: 0.005 mm) as a conductive hard carbon-containing material is formed by a sintering method, and the first sliding contact member used in this example is formed. Obtained. A ball-shaped aluminum member was used as the second sliding contact member used in this example. Aluminum has a higher oxide generation energy than conductive hard carbon.

[Performance evaluation]
A performance evaluation test was performed on the combination of sliding contact members of the above examples. Specifically, a ball-on-disk test according to JIS R 1613 was performed in the manner shown in FIG. 11 (however, in Example 4, the direction of connection of battery E was changed). In this test, the ball-shaped second sliding contact member 20 was slid on the disk-shaped first sliding contact member 10. In this test, the ball was fixed so as not to roll. Further, in this test, the combination of the sliding contact members is incorporated in a circuit to which the battery E is connected, and the first sliding contact member 10 is on the low potential side and the second sliding contact member 20 is on the high potential side. Arranged. In this test, the load was 10 N, and the rotation speed of the ball was 1000 rpm. Further, this test was performed at room temperature (25 ° C.) and without lubrication.

  FIGS. 12, 15, 16, and 17 are graphs showing the relationship between the current and the friction coefficient in Example 1, Example 2, Example 3, and Comparative Example 2, respectively. From these graphs, Examples 1 to 3 belonging to the scope of the present invention are a predetermined combination of the first sliding contact member and the second sliding contact member as compared with Comparative Example 2 outside the present invention. Therefore, it can be seen that the coefficient of friction can be reduced when energized while being in sliding contact. Moreover, it turns out that Example 1 which combined the conductive diamond containing material and copper can reduce a friction coefficient especially from these graphs.

13 and 14, the content of copper oxide was measured using a combination of each of Example 1 and the sliding contact member of Comparative Example 1 (II) (CuO) and copper oxide (I) _(Cu 2 O) It is a graph which shows a rate. In addition, the content rate of each copper oxide in a graph is the result of having measured the sliding surface (sliding trace) by X-ray photoelectron spectroscopy (XPS). From these graphs, Example 1 belonging to the scope of the present invention has more copper (I) oxide in the second sliding contact member energized while being in sliding contact than Comparative Example 1 outside the present invention. It is considered that the friction coefficient was reduced because this copper (I) oxide was formed on the sliding surface.

  Further, FIG. 18 shows the relationship between the current and the friction coefficient in Example 1 (the first sliding contact member is disposed on the low potential side) and Example 4 (the first sliding contact member is disposed on the high potential side). It is a graph to show. From this graph, it can be seen that the friction coefficient can be further reduced by using the first sliding contact member on the low potential side and the second sliding contact member on the high potential side.

  As mentioned above, although this invention was demonstrated with some embodiment and an Example, this invention is not limited to these, A various deformation | transformation is possible within the range of the summary of this invention.

  That is, in the said embodiment and Example, although the direct current motor was illustrated as what utilizes the combination of a sliding contact member, it is not limited to this, It can also apply to a direct current generator.

  Further, for example, the present invention can be applied to a combination of sliding contact members that are energized while being in sliding contact with a mating member such as an overhead wire and a pantograph, a current collecting rail and a current collecting shoe, and predetermined switches.

1A to 1H Combination of sliding contact members 10 First sliding contact member 10a Sliding surfaces 11, 12 First sliding member 13 Conductive hard carbon-containing material 15 Second conductive material 17 Porous body 19 Support body 20 Second Sliding contact member 20a Sliding surface 21 Second sliding member 23 First conductive material 29 Support 51 Motor case 52 Bearing 53 Armature 54 Coil 55 Magnet 56 Brush 57 Commutator (commutator)
N Jet nozzle H Heater F Feeder M DC motor E Battery

Claims (15)

A combination of sliding contact members comprising at least one first sliding contact member that is relatively slidingly contacted and at least one second sliding contact member that is a counterpart member of the first sliding contact member Because
At least a sliding surface of the first sliding contact member is constituted by a first sliding member containing a conductive hard carbon-containing material containing conductive hard carbon;
At least a sliding surface of the second sliding contact member is constituted by a second sliding member including a first conductive material having an oxide generation energy smaller than that of the conductive hard carbon.
A combination of sliding contact members characterized by that.   The combination of sliding contact members according to claim 1, wherein the first sliding member includes the conductive hard carbon-containing material and a second conductive material.   The combination of sliding contact members according to claim 2, wherein the first sliding member is made of a green compact containing the conductive hard carbon-containing material and the second conductive material.   The first sliding member is made of a green compact including a plurality of particles made of the conductive hard carbon-containing material and the second conductive material binding the conductive hard carbon-containing material particles. 4. A combination of sliding contact members according to claim 2 or 3, characterized in that   The first sliding member includes a porous body having a structure in which a plurality of particles made of the conductive hard carbon-containing material are bonded to each other, and the second conductive material included in a gap between the porous bodies. 4. The combination of sliding contact members according to claim 2, wherein the sliding contact member is made of a green compact.   The combination of sliding contact members according to claim 2, wherein the first sliding member is made of a deposit including the conductive hard carbon-containing material and the second conductive material.   The combination of sliding contact members according to claim 1, wherein the first sliding member is made of a deposit made of the conductive hard carbon-containing material.   The conductive hard carbon-containing material is made of conductive hard carbon, or contains conductive hard carbon and at least one catalyst component selected from the group consisting of cobalt, silicon, nickel, titanium, and boron. It consists of a composite material, The combination of the sliding contact member as described in any one of Claims 1-7 characterized by the above-mentioned.   The sliding contact according to any one of claims 2 to 6 or 8, wherein the second conductive material includes at least one selected from the group consisting of silver, copper, gold, and molybdenum. A combination of parts.   The combination of sliding contact members according to any one of claims 1 to 9, wherein the conductive hard carbon is a conductive diamond.   The combination of sliding contact members according to any one of claims 1 to 9, wherein the conductive hard carbon is conductive diamond-like carbon.   The sliding contact according to any one of claims 1 to 11, wherein the first conductive material includes at least one selected from the group consisting of copper, tin, nickel, cobalt, and iron. A combination of parts.   The combination of sliding contact members according to any one of claims 1 to 12, wherein the first conductive material includes copper or a copper alloy and another conductive material.   The said 1st electrically conductive material contains copper, and copper oxide (I) is formed in the at least sliding surface of the said 2nd sliding contact member, The term of any one of Claims 1-13 characterized by the above-mentioned. A combination of sliding contact members according to 1.   The first sliding contact member is used on a low potential side, and the second sliding contact member is used on a high potential side. Combination of sliding contact members.

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