JP2016180464A - Oil retaining slide member, oil retaining bearing, and manufacturing method of oil retaining slide member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oil retaining slide member which enables stable improvement of load bearing without deteriorating strength of a slide member, and to provide an oil retaining bearing and a manufacturing method of the oil retaining slide member.SOLUTION: An oil retaining slide member 10 supplies a liquid or semi-solid lubricant to a slide surface 12c of a member body 12, and a load bearing solid lubricant exists on the slide surface 12c.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an oil-impregnated sliding member, an oil-impregnated bearing, and an oil-impregnated sliding member manufacturing method, and more particularly to an oil-impregnated sliding member having improved load resistance.

  In an oil-impregnated sliding member such as an oil-impregnated bearing, lubricating oil contained in a metal or resin porous body is supplied to the sliding surface to obtain a lubricating action. For example, in the case of a bearing, the shaft is supported by a thin oil film when the load is small, and the solid surface of the shaft does not contact the solid surface of the bearing. Since the solid surface of the shaft and the solid surface of the bearing are in a fluid lubrication state separated by an oil film, there is little wear on the member, and the shaft can be used stably over a long period of time. However, when the load increases, the oil film cannot support the shaft and the solid surfaces come into contact with each other. As time passes, so-called seizure occurs, the friction coefficient increases, and wear begins to progress. If the wear exceeds a certain level, it can no longer be used as a bearing, which causes a shortened life. Therefore, if the seizure can be suppressed even when a large load is applied, the load resistance of the oil-impregnated sliding member can be improved.

  In order to increase the load resistance of a sliding member such as a bearing, it has been proposed to use a lubricating oil composition in which a solid lubricant or an extreme pressure additive is blended with a lubricating oil (for example, Patent Documents 1 and 2). . In addition, a method of incorporating a solid lubricant into the bearing (for example, Patent Document 3) and a method of forming a film containing the solid lubricant on the surface of the bearing using a binder or the like (for example, Patent Document 4) have been proposed. Yes. Furthermore, a method has also been proposed in which a hole is provided in the sliding member and a lubricating composition containing a solid lubricant, a lubricating oil, and a resin component is embedded in the hole (for example, Patent Document 5).

JP 2008-255271 A JP-A-8-295896 JP 2001-132755 A JP 2005-89514 A JP-A-6-979

  However, the method according to the above patent document is not satisfactory in order to increase the load resistance of the oil-containing sliding member.

  That is, in the lubricating oil composition described in Patent Document 1, it is necessary to increase the amount of solid lubricant added in order to sufficiently obtain the effect of the solid lubricant. The dispersion stability is lowered, and the solid lubricant aggregates and settles. Moreover, it is known that the extreme pressure additive as described in Patent Document 2 generally contains a sulfur component and has a corrosive action. Therefore, there is a limit to the amount used. In either case, the effects of the solid lubricant and the extreme pressure additive are limited, and the load resistance of the sliding member cannot be sufficiently increased.

  In the method according to Patent Document 3, when the ratio of the solid lubricant in the bearing is increased in order to enhance the effect of the solid lubricant, the ratio of the main component of the bearing is decreased and the strength of the bearing is decreased. In this case, a problem such as an increase in cost also occurs. Further, in the method according to Patent Document 4, the surface of the bearing is covered with a film to close the hole in the surface, so that the oil supply mechanism from the inside is lost. For this reason, it cannot be applied to an oil-impregnated sliding member to which lubricating oil is supplied from the inside of the member via a fine hole.

  The method according to Patent Document 5 is difficult to apply to a porous body having micropores in that a hole is provided in a member. When applied to a porous body, since the lubricating oil is contained in the lubricating composition, a smooth supply from the inside cannot be expected. Moreover, since the solid lubricant is embedded in the hole together with the resin component and the like and does not exist on the surface of the member, the effect of the solid lubricant is not sufficiently exhibited.

  Therefore, an object of the present invention is to provide an oil-impregnated sliding member, an oil-impregnated bearing, and a method for manufacturing the oil-impregnated sliding member that stably improve the load resistance without reducing the strength of the sliding member.

  A first aspect of the present invention is an oil-containing sliding member capable of supplying a liquid or semi-solid lubricant to a sliding surface of a member body, wherein a load-bearing solid lubricant is present on the sliding surface. It is characterized by that.

  A second aspect of the present invention is the invention based on the first aspect, wherein the member main body is a porous shape having micropores, and the liquid or semi-solid lubricant is a component of the member main body. It is filled in the micropores.

  A third aspect of the present invention is the invention based on the first or second aspect, characterized in that the surface coverage of the load-bearing solid lubricant on the sliding surface exceeds 60%. .

  A fourth aspect of the present invention is an invention based on any one of the first to third aspects, wherein the load-bearing solid lubricant is a primary particle obtained based on observation with a scanning electron microscope. It contains particles having an average particle size of 1 μm or less.

  A fifth aspect of the present invention is an invention based on any one of the first to fourth aspects, wherein the load-bearing solid lubricant includes a nanocarbon material.

  A sixth aspect of the present invention is an invention based on any one of the first to fifth aspects, wherein the sliding surface is used in a boundary lubrication or mixed lubrication state.

  A seventh aspect of the present invention is characterized by using any of the oil-containing sliding members described above.

  According to an eighth aspect of the present invention, there is provided a step of disposing the load-bearing solid lubricant on the sliding surface of the member body using a dispersion containing a load-bearing solid lubricant; A step of impregnating the member main body on which the load-bearing solid lubricant is disposed with a liquid or semi-solid lubricant.

  According to a ninth aspect of the present invention, there is provided a liquid or semi-solid lubricant using a step of impregnating a member body with a liquid or semi-solid lubricant and a dispersion containing a load-bearing solid lubricant. And a step of disposing the load-bearing solid lubricant on the sliding surface of the member body impregnated with.

  In the oil-impregnated sliding member according to the first to seventh aspects of the present invention, the presence of a load-bearing solid lubricant on the sliding surface of the member main body prevents seizure without reducing the strength of the sliding member. It can suppress and can improve load resistance.

  In the oil-impregnated sliding member according to the second aspect of the present invention, self-lubrication is performed by filling a liquid or semi-solid lubricant in the micropores of the member body made of a porous sintered metal. be able to.

  In the oil-impregnated sliding member of the third aspect of the present invention, the surface coverage of the load-bearing solid lubricant on the sliding surface is more than 60%, so the load bearing is further improved and the friction coefficient is further reduced. can do.

  In the oil-impregnated sliding member according to the fourth aspect of the present invention, the load-bearing solid lubricant includes particles having an average primary particle size of 1 μm or less, thereby further increasing the load-bearing capability and further increasing the friction coefficient. It can be further reduced.

  In the oil-impregnated sliding member according to the fifth aspect of the present invention, the load-bearing solid lubricant contains the nanocarbon material, so that the load-bearing property can be further increased and the friction coefficient can be further reduced.

  In the oil-impregnated sliding member of the sixth aspect of the present invention, the sliding surface is used in the state of boundary lubrication or mixed lubrication, so that the effect of the load-bearing solid lubricant existing on the sliding surface is sufficiently obtained. Can be demonstrated.

  In the manufacturing method of the oil-impregnated sliding member according to the eighth and ninth aspects of the present invention, the load-bearing solid lubricant can be disposed on the sliding surface of the member main body. A member can be manufactured.

It is a longitudinal cross-sectional view of the oil-containing sliding member which concerns on embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

1. Overall Configuration FIG. 1 is a longitudinal sectional view of an oil-impregnated bearing 10 as an oil-impregnated sliding member according to this embodiment. The illustrated oil-impregnated bearing 10 includes a member body 12 having a sliding surface. The member body 12 is a porous sintered metal. In the present embodiment, the member main body 12 is formed in a substantially cylindrical shape. The member body 12 used in the present embodiment preferably has a dry density of 5.2 to 7.5 g / cm ³ and an oil content of 15 to 27 vol%. In general, the dry density and oil content of the member body 12 are determined according to JIS standard Z2501: 2000.

  The member main body 12 has fine holes having a diameter of about 1 to 20 μm, and the fine holes are three-dimensionally continuous. In general, the diameter of the micropores can be determined by a mercury intrusion method. The micropores are filled with a liquid or semi-solid lubricant, and this lubricant oozes out on the sliding surface to form a lubricating oil film and imparts a lubricating action to the sliding surface. Examples of the liquid or semi-solid lubricant to be filled include oil, grease, and ionic liquid.

  Inside the member main body 12, a shaft body 14 is rotatably supported from one end surface 12a to the other end surface 12b. An axial load is applied to the one end face 12a from the flange 16 provided integrally with the shaft body 14.

  The inner peripheral surface 12c of the member main body 12 functions as a sliding surface. A load-bearing solid lubricant (not shown) (hereinafter referred to as a solid lubricant) is present on the inner peripheral surface 12c. In the present embodiment, the solid lubricant is provided on the inner peripheral surface 12c in direct contact with the surface of the inner peripheral surface 12c. The surface of the shaft body 14 is separated from the inner peripheral surface 12c of the member main body 12 by a lubricating oil film made of a liquid or semi-solid lubricant at normal temperature and a solid lubricant. Therefore, the solid lubricant is required to be present on the inner peripheral surface 12c so as not to prevent the liquid or semi-solid lubricant from exuding from the inside of the member main body 12.

In order to sufficiently obtain the effect of the solid lubricant, the solid lubricant is preferably present over the entire inner peripheral surface 12c, but this is not always essential. If the solid lubricant is disposed on the inner peripheral surface 12c so that the surface coverage required by the following method exceeds 30%, the seizure on the inner peripheral surface 12c is suppressed and the coefficient of friction is further reduced. Can do. In order to sufficiently reduce the coefficient of friction, the surface coverage is preferably more than 60%. In order to obtain the surface coverage, first, 100 unit regions (regions of 10 μm ² ) on the inner peripheral surface 12c on which the solid lubricant is arranged are observed at 100 locations by a scanning electron microscope (SEM). The ratio of the unit region in which the presence of the solid lubricant is confirmed among the observed 100 locations is defined as the surface coverage.

  Examples of the solid lubricant include nanocarbon materials such as carbon black, carbon nanotube, carbon nanofiber, fullerene, and nanodiamond. Graphite, boron nitride, molybdenum disulfide, or fluororesin particles may be used as the solid lubricant, but it is preferable to use a nanocarbon material. Since the solid lubricant made of the nanocarbon material can be disposed on the inner peripheral surface 12c of the member body 12 without using a resin, a binder, or the like, liquid or semi-solid lubrication from the inside to the inner peripheral surface 12c. There is no risk of preventing the exudation of the agent.

  On the inner peripheral surface 12c as the sliding surface, the solid lubricant is preferably present in the form of particles, and the average particle size of the primary particles is preferably 1 μm or less. When the average particle size of the solid lubricant is 1 μm or less, the friction coefficient on the inner peripheral surface 12c can be sufficiently reduced. The average particle diameter of the solid lubricant present on the inner peripheral surface 12c can be determined by, for example, SEM observation. Specifically, the image can be obtained by observing the inner peripheral surface 12c on which the solid lubricant is disposed with an SEM, obtaining an image, and calculating the size of one pixel of the image. Alternatively, the average particle diameter of the solid lubricant may be obtained by observing a transmission electron microscope (TEM) for the solid lubricant dropped from the inner peripheral surface 12c by ultrasonic cleaning in alcohol. Good.

2. Manufacturing Method The oil-impregnated bearing 10 of the present embodiment can be manufactured by disposing a solid lubricant on the sliding surface of the member body 12 and impregnating the member body 12 with a liquid or semi-solid lubricant.

  In order to dispose the solid lubricant on the inner peripheral surface 12c as the sliding surface, a dispersion containing a solid lubricant (hereinafter referred to as a solid lubricant dispersion) is used. The solid lubricant dispersion can be prepared by dispersing a predetermined solid lubricant in a dispersion medium such as water and performing a dispersion treatment for about 1 hour. The dispersion treatment can be performed using, for example, an ultrasonic homogenizer. At this time, a dispersant in an amount of about 0.1 to 10 wt% may be blended with the solid lubricant. Examples of the dispersant include polyvinyl pyrrolidone (PVP) and sodium cholate hydrate.

  The dispersion medium may contain an alcohol such as methanol. Methanol can reduce the viscosity of the dispersion and improve the coating properties. The weight ratio of water to methanol (water: methanol) can be about 50:50 to 95: 5. The concentration of the solid lubricant in the dispersion is preferably about 0.1 to 20 wt%, more preferably about 1 to 5 wt%.

  After the solid lubricant dispersion is applied to the inner peripheral surface 12c of the member body 12, the solid lubricant is disposed on the inner peripheral surface 12c of the member body 12 by drying and pressing. The solid lubricant dispersion can be applied by, for example, dropping onto the inner peripheral surface 12c of the member body 12 using a micropipette and then spin-coating. As will be described later, the member main body 12 is impregnated with a liquid or semi-solid lubricant, and this lubricant is supplied to the inner peripheral surface 12c as a sliding surface. If a part of the inner peripheral surface 12c is exposed, the liquid portion or the semisolid lubricant is smoothly impregnated and supplied in the exposed portion. Therefore, it is preferable to apply the solid lubricant dispersion by adjusting the concentration of the dispersion and the coating conditions so that the entire inner peripheral surface 12c of the member body 12 is not completely covered with the solid lubricant dispersion.

The solid lubricant dispersion applied to the inner peripheral surface 12c of the member main body 12 can be dried by, for example, holding at 60 ° C. for 12 hours. Then, a solid lubricant is arrange | positioned on the internal peripheral surface of the member main body 12, for example by performing the press for 1 to 10 minutes with the pressure used as 1-10 * 10 < ³ > kg / cm < ² >.

  After the solid lubricant is disposed on the inner peripheral surface 12c of the member main body 12, the member main body 12 is impregnated with a liquid or semi-solid lubricant. For example, the member main body 12 in which the solid lubricant is disposed on the inner peripheral surface 12c is immersed in a liquid or semi-solid lubricant, and the liquid or semi-solid lubricant is made into a member by evacuation of about 1 to 100 mmHg. The main body 12 is impregnated. The impregnation time is not particularly limited, but can generally be 1 to 12 hours.

  In the case of this embodiment, before impregnating the member main body 12 made of a porous sintered metal with a liquid or semi-solid lubricant, the solid lubricant dispersion is used as an inner periphery as a sliding surface of the member main body 12. It was decided to apply to the surface 12c. As a result, the solid lubricant can be uniformly disposed on the inner peripheral surface 12 c of the member main body 12. The solid lubricant is basically present on the surface of the member main body 12, but the solid lubricant is one of the solid lubricants in the micropores of the member main body 12 by the treatment of impregnating the liquid or semi-solid lubricant. The part may enter.

  As described above, the member body 12 made of a porous sintered metal is impregnated with a liquid or semi-solid lubricant, and the solid lubricant is disposed on the inner peripheral surface 12c as a sliding surface. The oil-impregnated bearing 10 having the form is obtained.

3. Action and Effect In the oil-impregnated bearing 10 according to the present embodiment, a liquid or semi-solid lubricant is supplied from the inside of the member main body 12 to the inner peripheral surface 12c as a sliding surface, and further, on the inner peripheral surface 12c. A solid lubricant is present. In the oil-impregnated bearing 10 according to the present embodiment, a sufficient lubricating action is given to the inner peripheral surface 12c of the member main body 12 by the lubricating oil film and the solid lubricant made of the liquid or semi-solid lubricant.

  Generally, the oil-impregnated bearing 10 is used with a surface pressure of about 1 to 10 MPa. The oil-impregnated bearing 10 of the present embodiment is so-called boundary lubrication or mixed lubrication when a part of the lubricating oil film is damaged due to high surface pressure and the inner peripheral surface 12c of the member body 12 contacts the solid surface of the shaft body 14. Even in this state, the lubricating action of the inner peripheral surface 12c is maintained by the solid lubricant. Due to the lubricating action caused by the solid lubricant, an increase in the coefficient of friction on the inner peripheral surface 12c is avoided even when a high surface pressure is applied, and the wear of the member does not proceed. In the boundary lubrication, the inner peripheral surface 12c of the member main body 12 and the solid surface of the shaft body 14 are provided even though a lubricating oil film exists between the inner peripheral surface 12c of the member main body 12 and the solid surface of the shaft body 14. Are in partial contact with each other. Mixed lubrication is a state in which a fluid lubrication portion and a boundary lubrication portion are mixed.

  Thus, the oil-impregnated sliding member 10 according to the present embodiment can dispose the solid lubricant on the inner peripheral surface 12c without changing the configuration of the member body 12 formed of sintered metal. The load resistance can be increased without lowering. The oil-impregnated bearing 10 according to this embodiment is particularly effective when used at a relatively high surface pressure of about 5 MPa or more.

  When the solid lubricant is disposed on the inner peripheral surface 12c as a sliding surface without using a resin or a binder, the fine holes of the member main body 12 are not blocked by the resin or the like. The liquid or semi-solid lubricant impregnated inside is satisfactorily supplied to the inner peripheral surface 12c, and a lubricating oil film can be formed. Accordingly, the lubricating action of the liquid or semi-solid lubricant and the solid lubricant can be maintained for a long period of time.

  As described above, in the present embodiment, the solid lubricant is present on the inner peripheral surface 12 c as the sliding surface of the member main body 12. Unlike the case where the solid lubricant is contained in the member main body 12, the member main body 12 can maintain the original strength because it does not affect the composition of the sintered metal constituting the member main body 12. . In addition, in the present embodiment, it is not necessary to consider the dispersibility of the solid lubricant in the lubricating oil impregnated in the member main body 12, and it is advantageous in that the degree of freedom in selecting the solid lubricant is expanded.

4). The present invention is not limited to the above-described embodiment, and can be appropriately changed within the scope of the gist of the present invention.

  In the above-described embodiment, the oil-impregnated bearing is used as the oil-impregnated sliding member, but a sliding member such as a bush can be used in addition to the bearing. Although the inner peripheral surface of the oil-impregnated bearing has been described as an example of the sliding surface, depending on the type of the sliding member, a surface other than the inner peripheral surface may be the sliding surface. The material of the member main body is not limited to metal, and may be ceramic, resin, or resin containing porous ceramic.

  In manufacturing the oil-impregnated bearing, after impregnating a member body made of a porous sintered metal with a liquid or semi-solid lubricant, the solid lubricant may be disposed on the sliding surface. When the solid lubricant is not present on the surface, the member body is more smoothly impregnated with the liquid or semi-solid lubricant. In this case, since the liquid or semi-solid lubricant is impregnated in the member body in advance, there is no particular need to limit the arrangement of the solid lubricant on the sliding surface.

  The solid lubricant dispersion can also be applied to the sliding surface of the member body by spin coating or spraying. In some cases, the solid lubricant can be disposed on the sliding surface by applying the solid lubricant dispersion and allowing it to stand to dry naturally.

  As described above, the solid lubricant is required to be present on the sliding surface of the member main body so as not to prevent the liquid or semi-solid lubricant from exuding from the inside of the member main body. If this is achieved, the solid lubricant may be disposed on the sliding surface using other components such as a resin and a binder.

5. Examples In the following examples, a solid lubricant is disposed on the surface of a member body made of sintered metal, and a lubricant is prepared as a liquid or semi-solid lubricant to prepare a sample. The load resistance of the sample was examined by measuring the dynamic friction coefficient of the surface on which the solid lubricant was disposed.

Example 1
<Production of member body>
Cu powder, tin powder, and graphite as raw material powders were mixed to obtain a mixed powder so as to have a composition of Cu: 88 wt%, Sn: 10 wt%, C: 2 wt%, and this was pressed by a conventional method A molded body of φ30 mm and L10 mm was produced. The obtained molded body was sintered in an inert atmosphere at 750 ° C. for 30 minutes by a conventional method to produce a member body made of sintered metal. The obtained member main body had a dry density obtained by JIS standard Z2501: 2000 of 6.6 g / cm ³ and an oil content of 20 vol%.

<Arrangement of solid lubricant>
Carbon nanofibers (CNF) (CNano Technology Ltd .: Flotube 9000) as a solid lubricant was oxidized in a solution of nitric acid: sulfuric acid = 1: 3 at 60 ° C. for 24 hours, and then subjected to dispersion treatment. An ultrasonic homogenizer (manufactured by Qsonica: Q700) was used for the dispersion treatment, and the treatment condition was 280 W for 2 hours (pulse interval: 30 sec). After the dispersion treatment, 20 wt% methanol was further added to obtain a CNF dispersion as a solid lubricant dispersion. The CNF concentration in the dispersion was 0.05 wt%.

The entire surface of the above-mentioned member main body was covered with 100 μL of this dispersion, and dried by holding at 60 ° C. for 12 hours. Then, it pressed for 1 minute with the force used as a pressure 1.0 * 10 < ³ > kg / cm < ² > (98MPa) using a hand press, and CNF as a solid lubricant was arrange | positioned on the surface of the member main body.

<Impregnation of liquid or semi-solid lubricant>
Lubricating oil (JX Nippon Oil & Energy Co., Ltd .: Turbine oil) was prepared as a liquid lubricant, and a member main body having CNF disposed on the surface thereof was immersed therein. The member body was impregnated with lubricating oil by evacuating 10 mmHg for 4 hours. Thus, the sample of Example 1 was obtained in which the member main body was impregnated with the lubricating oil and CNF was disposed on the surface.

  Further, samples of Examples 2 to 11 and Comparative Example were produced by the same method as in Example 1 except that the following points were changed.

(Example 2)
Using a micropipette, 80 μL of a solid lubricant dispersion was dropped onto the member body, and about 80% of the surface was covered in a spot manner.

Example 3
Using a micropipette, 60 μL of a solid lubricant dispersion was dropped onto the member body, and about 60% of the surface was covered in a spot manner.

Example 4
Using a micropipette, 20 μL of a solid lubricant dispersion was dropped onto the member body, and about 20% of the surface was spot-covered.

(Example 5)
CNF as a solid lubricant was changed to fullerene (Sigma Aldrich Corp .: product number 572500). Moreover, the oxidation process was not performed but the dispersion process was performed with PVP (10 wt% with respect to K = 30 CNF) as a dispersing agent.

(Example 6)
CNF as a solid lubricant was changed to carbon black (Mitsubishi Chemical Corporation: # 2650). Also, no oxidation treatment was performed and no dispersant was used.

(Example 7)
The CNF dispersion as the solid lubricant dispersion was changed to a diluted solution of boron nitride (BN) dispersion (MARUKA: Ultracoat, C type). The boron nitride dispersion was diluted with a mixed solution of water and methanol (water: methanol = 80: 20 weight ratio) so that the solid content concentration was 0.05 wt%.

(Example 8)
CNF as a solid lubricant was changed to molybdenum disulfide powder (Sigma Aldrich Corp .: product number 234842), and PVP was changed to sodium cholate hydrate (Sigma Aldrich Corp .: product number C1254).

Example 9
A sintered metal obtained by changing the type and blending amount of the raw material powder was used as a member body. The composition of the sintered metal is Cu: 40 wt%, Fe: 55 wt%, Sn: 5 wt%, and the dry density and oil content of the member body made of this sintered metal are 6.2 g / cm ³ and 25 vol%, respectively. Met.

(Example 10)
A sintered metal obtained by changing the type and blending amount of the raw material powder was used as a member body. The composition of the sintered metal was Fe: 77 wt%, Sn: 1 wt%, C: 2 wt%, Cu: 20 wt%, and the dry density and oil content of the sintered body of the member body were 5.8 g / It was cm ³ and 24vol%.

(Example 11)
First, the member main body was impregnated with lubricating oil, and then a solid lubricant dispersion was applied to the surface of the member main body. In the preparation of the solid lubricant dispersion, the water: methanol weight ratio was changed to 10:90, and the dispersion operation was performed in 100% water. 1 mL of the dispersion thus obtained was applied to the surface of the member body impregnated with the lubricating oil by spin coating (3000 rpm, 1 minute). Then, it pressed for 1 minute with the force used as a pressure 1.0 * 10 < ³ > kg / cm < ² > (98MPa) with a hand press.

  In the samples of Examples 2 to 11, as in the sample of Example 1, the member body is impregnated with lubricating oil, and a solid lubricant is disposed on the surface of the member body.

(Comparative example)
The member body was not subjected to the treatment using the solid lubricant dispersion, and was subjected to press and lubricating oil impregnation. In the sample of the comparative example, no solid lubricant is arranged on the surface of the member main body.

  The physical property values of the samples (Examples 1 to 11 and Comparative Examples) obtained as described above are summarized in Table 1 below together with the configuration of the samples. As physical property values, the average particle size and surface coverage of the solid lubricant, the surface pressure, the dynamic friction coefficient, and the presence or absence of seizure were determined by the following methods.

<Average particle size of solid lubricant>
The solid lubricant arranged on the surface of the member body was observed by SEM or TEM to obtain an image, and the average particle size of the primary particles was obtained from the result. For anisotropic particles (carbon nanofibers, boron nitride (BN), molybdenum disulfide), the maximum length was taken as the particle size.

<Surface coverage>
The image of the unit area of 10 μm ² was observed at 100 locations by SEM, and the ratio of the unit area where the presence of the solid lubricant was confirmed was determined as the surface coverage.

<Surface pressure>
The surface pressure was calculated by dividing the apparent load by the contact area (the area of the measurement pin) in the measurement of the dynamic friction coefficient.

<Dynamic friction coefficient>
The dynamic friction coefficient was measured for a sample immediately after production using a friction and wear tester (Shinko Engineering Co., Ltd .: SZ-FT-93B). The sliding speed was set to 62 m / min, and a pin (Φ4) made of carbon steel (S45C) was used. The test was performed for 30 minutes with the pin rotating on the member body, and the arithmetic average of the values for the latter half of 15 minutes was obtained as the dynamic friction coefficient. For the sample of the comparative example in which the solid lubricant is not disposed on the surface of the member body, the dynamic friction coefficient of an arbitrary surface was measured.

<Presence of burn-in>
Whether or not seizure occurred was judged that seizure occurred when the coefficient of dynamic friction during measurement increased rapidly and the sliding sound continued to be abnormally loud.

  In Table 1, “NA” is an abbreviation for “Not Available” and indicates that no data exists. As shown in Table 1 above, burn-in occurs in the sample of the comparative example, but no burn-in occurs in the sample of the example. From this, it can be seen that the load resistance of the sample of the example was enhanced. In addition, the friction coefficient of the sample in which no seizure has occurred remains small. In particular, when a nanocarbon material such as carbon nanofiber, carbon black, or fullerene was used as the solid lubricant, the dynamic friction coefficient was further reduced.

  The larger the surface coverage of the solid lubricant on the surface of the member body, the smaller the dynamic friction coefficient tends to be. If the surface coverage of the solid lubricant exceeds 60%, a dynamic friction coefficient of less than 0.098 is obtained. Yes. Further, the smaller the average particle size of the solid lubricant is, the smaller the dynamic friction coefficient tends to be. If the average particle size of the solid lubricant is 1 μm or less, the dynamic friction coefficient can be suppressed to less than 0.092.

  In the above, a sample obtained by placing a solid filler on the surface of a member body made of sintered metal and impregnating a lubricating oil as a liquid or semi-solid lubricant inside is given as an example, It was shown that the load resistance can be increased and the coefficient of friction can be further reduced. Similarly to these samples, a liquid or semi-solid lubricant is contained inside the member body, and if the solid lubricant is disposed on the sliding surface, it may be an oil-impregnated sliding member such as an oil-impregnated bearing. Similarly, load resistance can be increased and the coefficient of friction can be further reduced.

10 Oil-impregnated bearing (oil-impregnated sliding member)
12 Member body 14 Shaft body 16 鍔

Claims (9)

An oil-containing sliding member capable of supplying a liquid or semi-solid lubricant to a sliding surface of a member body, wherein a load-bearing solid lubricant is present on the sliding surface. .   2. The oil-impregnated slide according to claim 1, wherein the member main body is porous having fine holes, and the liquid or semi-solid lubricant is filled in the fine holes of the member main body. Moving member.   The oil-impregnated sliding member according to claim 1 or 2, wherein a surface coverage of the load-bearing solid lubricant on the sliding surface exceeds 60%.   The load-bearing solid lubricant includes particles having an average particle diameter of primary particles obtained based on observation with a scanning electron microscope of 1 µm or less. Oil-impregnated sliding member.   The oil-impregnated sliding member according to any one of claims 1 to 4, wherein the load-bearing solid lubricant includes a nanocarbon material.   6. The oil-impregnated sliding member according to any one of claims 1 to 5, wherein the sliding surface is used in a boundary lubrication or mixed lubrication state.   An oil-impregnated bearing using the oil-impregnated sliding member according to any one of claims 1 to 6. Using a dispersion containing a load-bearing solid lubricant, placing the load-bearing solid lubricant on the sliding surface of the member body; and
And a step of impregnating the member main body, on which the load-bearing solid lubricant is disposed, on the sliding surface with a liquid or semi-solid lubricant. Impregnating the member body with a liquid or semi-solid lubricant;
Disposing the load-bearing solid lubricant on a sliding surface of a member body impregnated with the liquid or semi-solid lubricant using a dispersion containing the load-bearing solid lubricant. The manufacturing method of the oil-impregnated sliding member characterized by these.

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