Sliding component

Abstract

Provided is a sliding component which has excellent wear resistance while retaining self-lubricating properties.　The sliding component has a sliding surface which slides relatively to a mating surface, and comprises coke and graphite as carbonaceous materials and a carbide of a resin, wherein the graphite is contained in an amount larger than 0 wt% but less than 6 wt% and the coke is a major component of the carbonaceous materials.

Description

Sliding parts

[0001] The present invention relates to a sliding part that slides relative to one another, and relates to a sliding part used in a shaft sealing device that seals the rotating shaft of a rotating machine in, for example, an automobile, general industrial machinery, or other sealing fields, or a sliding part used in a bearing of a machine in an automobile, general industrial machinery, or other bearing fields.

[0002] Sliding components have a sliding surface that slides relative to a mating sliding surface, and are used as components of bearings that support rotating or reciprocating shafts, etc., and shaft sealing devices that prevent leakage of sealed fluids. For example, a mechanical seal, an example of a shaft sealing device that prevents leakage of sealed fluids, is equipped with a pair of annular sliding components that rotate relative to each other and whose sliding surfaces slide against each other. For example, the carbon sliding component shown in Patent Document 1 is composed of main components that include graphite, coke, and non-graphitizable carbon powder, and a binder such as coal tar pitch.

[0003] Special Publication No. 3-12596 (page 2)

[0004] Graphite, which is used as the main component of conventional carbon sliding parts, has excellent self-lubricating properties, so increasing the graphite content makes it possible to reduce the coefficient of friction, suppress heat generation due to sliding, etc. However, graphite has the drawback of being soft, so increasing the graphite content significantly reduces friction resistance.

[0005] The present invention has been made in view of these problems, and has as its object to provide a sliding part that has excellent wear resistance while maintaining self-lubricating properties.

[0006] In order to solve the above problems, the present invention provides a sliding component having sliding surfaces that slide relative to one another, the sliding component including coke and graphite as carbonaceous materials, and a resin carbide, the graphite content being more than 0 wt % and less than 6 wt %, and the coke constituting a main component of the carbonaceous material. This ensures self-lubrication due to the graphite, while increasing strength and improving wear resistance because the main component of the carbonaceous material is hard coke.

[0007] The coke may be contained in an amount of 30 wt % or more, which can reliably improve the wear resistance.

[0008] The carbonaceous material may contain more than 0 wt % and less than 5 wt % of carbon black, which has good compatibility with resins and can form glassy carbon at grain boundaries to reinforce the sliding parts.

[0009] The material may contain more than 3 wt % and less than 12 wt % of clay as an additive, which can improve sliding characteristics and prevent cracks during firing due to the antifriction effect of the clay.

[0010] The carbonaceous material may contain activated carbon in an amount of more than 0 wt % and less than 20 wt %. By including activated carbon, which is harder than coke, the wear resistance of the sliding parts can be increased, and by providing roughness, the seizure resistance can be improved.

[0011] The resin charcoal may be contained in an amount of more than 10 wt % and less than 50 wt %, which makes it possible to increase the interparticle distance of the compounding materials other than the phenol resin and ensure roughness.

[0012] The resin carbide may be a phenolic resin carbide, which has high mechanical strength and leaves a relatively large amount of carbide after firing, improving the manufacturability of the sliding part.

[0013] The metal oxide may be contained as an additive in an amount of more than 0 wt % and less than 8 wt %. By containing a metal oxide having high hardness, the adhesive wear resistance of the sliding part can be improved.

[0014] The composite material may contain more than 0 wt% and less than 6 wt% of graphite, more than 0 wt% and less than 5 wt% of carbon black, more than 3 wt% and less than 12 wt% of clay, more than 0 wt% and less than 20 wt% of activated carbon, more than 10 wt% and less than 50 wt% of the resin carbonized material, and the remainder being the coke. This can increase mechanical strength.

[0015] The material may contain more than 0 wt% and less than 6 wt% of graphite, more than 0 wt% and less than 5 wt% of carbon black, more than 3 wt% and less than 12 wt% of clay, more than 0 wt% and less than 20 wt% of activated carbon, more than 10 wt% and less than 50 wt% of the resin carbide, more than 0 wt% and less than 8 wt% of metal oxide, and the balance being the coke. This can increase mechanical strength and adhesive wear resistance.

[0016] The sliding surface layer of the sliding component does not need to be impregnated with resin. In this case, since the sliding component itself is dense, it can be used without resin impregnation for the purpose of sealing pores, and can be used in a wide range of environments.

[0017] FIG. 1 is a table showing the compounded compositions and each item evaluated for function of Examples 1 and 2 and Comparative Examples 1 and 2 of sliding parts according to Embodiment 1 of the present invention. FIG. 1 is a table showing the compounded compositions and each item evaluated for function of Examples 3 and 4 and Comparative Examples 3 and 4 of sliding parts. FIG. 1 is a table showing the compounded compositions and each item evaluated for function of Examples 5 and 6 and Comparative Examples 5 and 6 of sliding parts. FIG. 1 is a table showing the compounded compositions and each item evaluated for function of Examples 7 and 8 and Comparative Examples 7 and 8 of sliding parts. FIG. 1 is a table showing the compounded compositions and each item evaluated for function of Examples 9 and 10 and Comparative Examples 9 and 10 of sliding parts. FIG. 1 is a table showing the compounded compositions and each item evaluated for function of Examples 21 to 23 of sliding parts. FIG. 1 is a table showing the basic evaluation results of Examples 21 to 23 of sliding parts and conventional Comparative Example 21. FIG. 2 is a cross-sectional view showing a testing machine used for functional evaluation of sliding parts according to Embodiment 1. FIG. 3 is a table showing the compounded compositions and each item evaluated for function of Examples 31 and 32 and Comparative Examples 31 and 32 of sliding parts according to Embodiment 2 of the present invention. FIG. 1 is a table showing the compounded compositions of Examples 33 and 34 and Comparative Examples 33 and 34 of sliding parts and the respective items for which their functions were evaluated. FIG. 2 is a table showing the compounded compositions of Examples 35 and 36 and Comparative Examples 35 and 36 of sliding parts and the respective items for which their functions were evaluated. FIG. 3 is a table showing the compounded compositions of Examples 37 and 38 and Comparative Examples 37 and 38 of sliding parts and the respective items for which their functions were evaluated. FIG. 4 is a table showing the compounded compositions of Examples 39 to 41 and Comparative Examples 39 and 40 of sliding parts and the respective items for which their functions were evaluated. FIG. 5 is a table showing the compounded compositions of Examples 51 to 54 of sliding parts and the respective items for which their functions were evaluated. FIG. 6 is a table showing the basic evaluation results of Examples 51 to 54 of sliding parts and conventional Comparative Example 21. FIG. 7 is a table showing the compounded compositions of Examples 42 to 44 and Comparative Examples 41 and 42 of sliding parts and the respective items for which their functions were evaluated. FIG. 8 is a table showing the compounded compositions of Examples 55 and 56 of sliding parts and the respective items for which their functions were evaluated. FIG. 10 is a table showing the basic evaluation results of Examples 55 and 56 of sliding parts and Comparative Example 21 of the related art.

[0018] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A sliding element according to the present invention will be described below based on an embodiment.

[0019] [Embodiment 1] The sliding part is described by taking an example of an embodiment in which the sliding part is a mechanical seal. The sliding part is made of raw materials including pitch coke, artificial graphite, carbon black (C.B.), clay, activated carbon, and resin. These raw materials are blended in the weight ratios shown in Fig. 1, etc., kneaded, and pulverized, and then pressed into a predetermined ring shape at a pressure of 150 kg / cm. ２ It is manufactured by hot pressing and then heat treating at 1000°C or higher.

[0020] Pitch coke, a carbonaceous material, is the main component of the carbonaceous material that constitutes the skeletal structure of the sliding parts. As will be described in detail later, artificial graphite, carbon black (C.B.), and activated carbon, which are also carbonaceous materials, are present in small amounts whose combined weight percentage does not exceed that of pitch coke. In other words, in this specification, the term "main component of a carbonaceous material" means that the carbonaceous material accounts for 40 wt % or more of the carbonaceous material.

[0021] Artificial graphite has the function of improving lubricity, carbon black has the function of reinforcing and improving wear resistance, clay has the function of reducing friction and improving resistance to cracking during firing and formability, and coconut shell activated carbon has the function of adding roughness and improving wear resistance.

[0022] (Materials) Pitch coke: particle size 10-40 μm Artificial graphite: particle size 10-40 μm Carbon black: particle size 19-60 nm Clay: particle size 2-30 μm Coconut shell activated carbon: particle size 2-30 μm Phenol resin

[0023] (Functional Evaluation) Sliding parts were formed using various blending ratios, and functional evaluation was carried out on the formed sliding parts of Examples 1 to 10 together with the sliding parts of Comparative Examples 1 to 10. For each evaluation item of function, predetermined standards were set to meet the targets of wear resistance, applicability to the usage environment, and further lubricity, as will be described in detail later.

[0024] The performance of the sliding component obtained by the above-described manufacturing method was evaluated using a test device shown in Figure 8. The test conditions for the performance evaluation will be described later. The test device 10 is mainly composed of a holding mechanism 12 that holds the sliding component obtained as described above as a fixed ring 11, an annular rotating ring 13 that serves as a mating member and is arranged opposite the fixed ring 11, and a rotating shaft 14 that rotates together with the rotating ring 13. The holding mechanism 12 also includes a spring (not shown) that biases the fixed ring 11 toward the rotating ring. The rotating ring 13 was made of SiC.

[0025] (Evaluation items) Product feasibility (formability) Firing cracks Material properties (hardness) HSD 110 or more Material properties (bending strength) 80 MPa or more Material properties (linear expansion coefficient) 2.0 x 10 －６ 1 / K or less Friction characteristics (friction coefficient 0.3 or less when sliding dry) Friction characteristics (heat generation 60°C or less when sliding dry) Wear resistance (surface roughness after sliding) Leakage (leakage amount 10mL / 100h or less) No squealing

[0026] (Test conditions) Basic evaluation conditions: dry Load: 0.25 MPa (33 N) Circumferential speed: 0.66 m / s (500 rpm) Sliding distance: 8000 m Atmosphere: air

[0027] Of these, the items "friction characteristics (friction coefficient of 0.3 or less during dry sliding)," "friction characteristics (heat generation of 60°C or less during dry sliding)," "wear resistance (surface roughness after sliding)," "leakage (leakage amount of 10 mL / 100 h or less)," and "absence of squealing" are evaluated based on the results obtained from tests under the above-mentioned test conditions.

[0028] (Examples 1 and 2) The results of the performance evaluation of Examples 1 and 2 and Comparative Examples 1 and 2 are summarized in the table of FIG.

[0029] In Examples 1 and 2 and Comparative Examples 1 and 2, the ratio of coke (pitch coke) to artificial graphite is different, but there is no relative difference in the weight percentages of the other carbon black (C.B.), kaolin clay, coconut shell activated carbon, and phenolic resin carbonized materials.

[0030] As shown in Figure 1, Comparative Example 1, which contains 0 wt% artificial graphite and 57 wt% pitch coke, does not meet the criteria for "friction characteristics (friction coefficient during dry sliding of 0.3 or less)." In contrast, Example 1, which contains 1.2 wt% artificial graphite and 55.8 wt% pitch coke, also meets the criteria for "friction characteristics (friction coefficient during dry sliding of 0.3 or less)."

[0031] Furthermore, as shown in Figure 1, Comparative Example 2, which contains 6 wt% artificial graphite and 51 wt% pitch coke, does not meet the criteria for "material characteristics (hardness) HSD 110 or more" and "friction characteristics (dry sliding friction coefficient 0.3 or less)." In contrast, Example 2, which contains 4.5 wt% artificial graphite and 52.5 wt% pitch coke, meets the criteria for all items. From this, it was found that the appropriate blending range of artificial graphite is more than 0 wt% and less than 6 wt%, preferably 1 wt% to 5 wt%, and more preferably 1.2 wt% to 4.5 wt%.

[0032] (Examples 3 and 4) The results of the performance evaluation of Examples 3 and 4 and Comparative Examples 3 and 4 are summarized in the table of FIG.

[0033] In Examples 3 and 4 and Comparative Examples 3 and 4, the weight percentages of pitch coke and carbon black (C.B.) are different, but there is no relative difference in the weight percentages of the other components, artificial graphite, kaolin clay, coconut shell activated carbon, and phenolic resin. The artificial graphite content is all 3 wt%, which conforms to the appropriate range of more than 0 wt% and less than 6 wt%.

[0034] As shown in Figure 2, Comparative Example 3, which contains 0 wt% carbon black and 55 wt% pitch coke, does not meet the criteria for "material characteristics (hardness) HSD 110 or more" and "wear resistance (surface roughness after sliding)." In contrast, Example 3, which contains 0.2 wt% carbon black and 54.8 wt% pitch coke, meets the criteria for all items.

[0035] Furthermore, as shown in Figure 2, Comparative Example 4, which contains 5 wt% carbon black and 50 wt% pitch coke, does not meet the criteria for "material characteristics (hardness) HSD 110 or more," "material characteristics (flexural strength) 80 MPa or more," and "wear resistance (surface roughness after sliding)." In contrast, Example 4, which contains 2.5 wt% carbon black and 52.5 wt% pitch coke, meets the criteria for all items. From this, it was found that the appropriate range of carbon black blending is more than 0 wt% and less than 5 wt%, preferably 0.1 wt% to 3 wt%, and more preferably 0.2 wt% to 2.5 wt%.

[0036] (Examples 5 and 6) The results of the performance evaluation of Examples 5 and 6 and Comparative Examples 5 and 6 are summarized in the table of FIG.

[0037] In Examples 5 and 6 and Comparative Examples 5 and 6, the weight percentages of pitch coke and kaolin clay are different, but there is no relative difference in the weight percentages of the other components, artificial graphite, carbon black (C.B.), coconut shell activated carbon, and phenolic resin. The weight percentages of all components other than kaolin clay are within the appropriate ranges, with all artificial graphite being 3 wt% and all carbon black being 1 wt%.

[0038] As shown in Figure 3, Comparative Example 5, which contains 3 wt% kaolin clay and 58 wt% pitch coke, does not meet the criteria for "cracks caused by firing," "friction characteristics (friction coefficient of 0.3 or less during dry sliding)," and "wear resistance (surface roughness after sliding)." Furthermore, it does not meet the criteria for "leakage (leakage amount 10 mL / 100 h or less)" during relative sliding with the rotating ring. In contrast, Example 5, which contains 5 wt% kaolin clay and 56 wt% pitch coke, meets the criteria for all items.

[0039] 3, Comparative Example 6, which contains 12 wt% kaolin clay and 49 wt% pitch coke, does not meet the criteria for "material properties (hardness) HSD 110 or more" and "friction properties (dry sliding friction coefficient 0.3 or less)." In contrast, Example 6, which contains 9 wt% kaolin clay and 52 wt% pitch coke, meets the criteria for all items. From this, it was found that the appropriate blending range of kaolin clay is more than 3 wt% and less than 12 wt%, preferably 4 wt% to 10 wt%, and more preferably 5 wt% to 9 wt%.

[0040] (Examples 7 and 8) The results of the performance evaluation of Examples 7 and 8 and Comparative Examples 7 and 8 are summarized in the table of FIG.

[0041] In Examples 7 and 8 and Comparative Examples 7 and 8, the weight percentages of pitch coke and coconut shell activated carbon are different, but there is no relative difference in the weight percentages of the other components, artificial graphite, carbon black (C.B.), kaolin clay, and phenolic resin. The weight percentages of all components other than coconut shell activated carbon are within appropriate ranges, with all artificial graphite being 3 wt%, all carbon black being 1 wt%, and all kaolin clay being 7 wt%.

[0042] As shown in FIG. 4, in Comparative Example 7, which contains 0 wt % coconut shell activated carbon and 64 wt % pitch coke, the "material property (linear expansion coefficient) 2.0 × 10 －６ It is found that the criteria for "friction characteristics (friction coefficient of 0.3 or less during dry sliding)" and "wear resistance (surface roughness after sliding)" are not met. Furthermore, it is found that the criteria for "no squealing" in relative sliding with the rotating ring are not met. In contrast, Example 7, which contains 8 wt% coconut shell activated carbon and 56 wt% pitch coke, meets the criteria for all items.

[0043] Furthermore, as shown in Figure 4, Comparative Example 8, which contains 20 wt% coconut shell activated carbon and 44 wt% pitch coke, does not meet the criteria for "cracks during firing," "friction characteristics (friction coefficient of 0.3 or less during dry sliding)," and "friction characteristics (heat generation of 60°C or less during dry sliding)." In contrast, Example 8, which contains 13 wt% coconut shell activated carbon and 51 wt% pitch coke, meets the criteria for all items. From these results, it was found that the coconut shell activated carbon should be blended in a range of more than 0 wt% and less than 20 wt%, preferably 2 wt% to 15 wt%, and more preferably 8 wt% to 13 wt%.

[0044] (Examples 9 to 11) The results of the performance evaluation of Examples 9 to 11 and Comparative Examples 9 and 10 are summarized in the table of FIG.

[0045] In Examples 9 to 11 and Comparative Examples 9 and 10, the weight percentages of pitch coke and phenolic resin were different, but there was no relative difference in the weight percentages of the other materials, artificial graphite, carbon black (C.B.), kaolin clay, and coconut shell activated carbon. The weight percentages of all materials other than the phenolic resin were within appropriate ranges: all artificial graphite was 3 wt%, all carbon black was 1 wt%, all kaolin clay was 7 wt%, and all coconut shell activated carbon was 10 wt%.

[0046] As shown in FIG. 5, in Comparative Example 9, which contains 10 wt % phenolic resin and 69 wt % pitch coke, the "product feasibility (moldability after mixing)" and "material properties (linear expansion coefficient) 2.0×10 －６ It is found that the standard for "1 / K or less" is not met. In addition, the condition for moldability after mixing is not met, and a sliding test using a testing device has not been conducted, so other items have not been evaluated. In contrast, Example 9, which contains 20 wt% phenolic resin and 59 wt% pitch coke, meets the standards for all items.

[0047] 5, Comparative Example 10, which contains 50 wt% phenolic resin and 29 wt% pitch coke, does not meet the criteria for "fire cracking," "material characteristics (hardness) HSD 110 or more," "friction characteristics (friction coefficient during dry sliding) 0.3 or less," "friction characteristics (heat generation during dry sliding 60°C or less)," and "wear resistance (surface roughness after sliding)." Furthermore, it does not meet the criteria for "leakage (leakage amount 10 mL / 100 h or less)" and "no squeal" during relative sliding with the rotating ring. In contrast, Example 11, which contains 40 wt% phenolic resin and 39 wt% pitch coke, meets the criteria for all items.

[0048] 5, Example 10, which contains 30 wt% phenolic resin and 49 wt% pitch coke, and is intermediate between Example 9 and Example 11, satisfies all the criteria. This indicates that the phenolic resin should be blended in a range of more than 10 wt% and less than 50 wt%, preferably 15 wt% to 45 wt%, and more preferably 20 wt% to 40 wt%.

[0049] (Examples 21 to 23) As shown in Figure 6, three Examples 21 to 23 were prepared using the weight percentages of the materials that passed the performance evaluation described above. Examples 21 to 23 met all criteria in the functional evaluation. Furthermore, as a conventional example, Comparative Example 21 was prepared, as shown in Patent Document 1, by using artificial graphite as the main component and resin as the binder, adding additives according to the application, and then mixing, molding, and firing. Examples 21 to 23 and Comparative Example 21 are formed with the same shape and dimensions as Examples 1 to 10 described above.

[0050] The results of the basic evaluation of Examples 21 to 23 and the conventional Comparative Example 21 are summarized in the table of FIG.

[0051] As shown in Figure 7, Examples 21 to 23 have values ​​equivalent to those of Comparative Example 21 for the coefficient of friction and hardness HSD, but are dramatically improved in bending strength MPa compared to Comparative Example 21. Furthermore, the values ​​of wear depth μm for Examples 21 to 23 are significantly reduced compared to Comparative Example 21. Thus, it was found that the sliding parts of Examples 21 to 23 satisfy the required standards for the coefficient of friction, i.e., lubricity and mechanical properties, and also have dramatically improved wear resistance compared to Comparative Example 21, which uses artificial graphite as the main component.

[0052] In addition, Examples 21 to 23 differ in the weight percentages of pitch coke and coconut shell activated carbon, but there is no relative difference in the weight percentages of the other components, artificial graphite, carbon black (C.B.), kaolin clay, and phenolic resin. Example 21 has the lowest weight percentage of activated carbon, and Example 23 has the highest weight percentage of activated carbon.

[0053] Although not shown in FIG. 7, it was found that the higher the weight percentage of coconut shell activated carbon, the more effective it was in suppressing a sudden increase in heat generation during sliding.

[0054] In Example 23, which had the highest weight percentage of coconut shell activated carbon, seizure occurred on the sliding surface beyond the standard range. Therefore, it can be said that it is more preferable to have the coconut shell activated carbon content less than 15 wt % in order to suppress the occurrence of seizure.

[0055] The above-mentioned functional evaluation revealed that by manufacturing sliding parts in which the artificial graphite content is more than 0 wt% but less than 6 wt% and pitch coke constitutes the main component of the carbonaceous material, it is possible to increase strength and improve wear resistance. Furthermore, by adding a small amount of artificial graphite, which has better self-lubricating properties than pitch coke, it is possible to reduce the friction coefficient of the sliding surface.

[0056] Furthermore, by including 30 wt % or more of pitch coke, which is harder than artificial graphite, it was possible to reliably improve wear resistance.

[0057] Furthermore, by including more than 0 wt % and less than 5 wt % of carbon black, which is compatible with phenolic resin, it was possible to reinforce the sliding parts while reducing the weight percentage of the binder.

[0058] Furthermore, by adding kaolin clay, which has a lower coefficient of friction than pitch coke, as an additive in an amount of more than 3 wt% but less than 12 wt%, the anti-friction effect of the kaolin clay can improve sliding properties and reduce the coefficient of friction, especially in dry environments. In addition, firing cracks can be prevented.

[0059] In addition, by including more than 0 wt% but less than 20 wt% coconut shell activated carbon, a carbonaceous material harder than pitch coke, the wear resistance of the sliding parts is increased and the roughness is imparted, thereby improving seizure resistance.

[0060] Furthermore, by including a phenolic resin in an amount of more than 10 wt% and less than 50 wt%, the interparticle distance of the compounded materials other than the phenolic resin can be increased to ensure roughness. From the viewpoint of expecting further improvement in roughness, the phenolic resin is preferably included in an amount of 20 wt% to 40 wt%, and more preferably in an amount of 20 wt% to 35 wt%.

[0061] Furthermore, by using a phenolic resin that has a high carbon content after firing (a high proportion of the resin is carbonized when fired), the productivity of the sliding parts can be improved.

[0062] Furthermore, by containing more than 0 wt% and less than 6 wt% artificial graphite, more than 0 wt% and less than 5 wt% carbon black, more than 3 wt% and less than 12 wt% kaolin clay, more than 0 wt% and less than 20 wt% coconut shell activated carbon, more than 10 wt% and less than 50 wt% phenolic resin, with the remainder being pitch coke, the weight percentage of phenolic resin can be relatively reduced, thereby effectively increasing mechanical strength.

[0063] From the viewpoint of expecting further improvement in mechanical strength, it is preferable to contain 1 wt% to 5 wt% of artificial graphite, 0.1 wt% to 3 wt% of carbon black, 4 wt% to 10 wt% of kaolin clay, 2 wt% to 15 wt% of coconut shell activated carbon, 15 wt% to 45 wt% of phenolic resin, and the balance being pitch coke. It is more preferable to contain 1.2 wt% to 4.5 wt% of artificial graphite, 0.2 wt% to 2.5 wt% of carbon black, 5 wt% to 9 wt% of kaolin clay, 8 wt% to 13 wt% of coconut shell activated carbon, 20 wt% to 40 wt% of phenolic resin, and the balance being pitch coke. Note that it may contain about 0.5 wt% of unavoidable impurities.

[0064] Furthermore, because coal tar pitch is not used as a binder, the generation of pores after firing is suppressed, resulting in a densely formed structure, eliminating the need for resin impregnation for the purpose of pore sealing. As such, the sliding surface layer of the sliding part is not impregnated with resin, resulting in excellent heat resistance and chemical resistance, allowing the sliding part to be used in a wide range of environments.

[0065] [Embodiment 2] Next, a sliding component according to embodiment 2 will be described below. Note that a description of the same configuration as embodiment 1 will be omitted.

[0066] The sliding parts are made of pitch coke, artificial graphite, carbon black (C.B.), clay, activated carbon, resin, titanium oxide (IV) (TiO ２ These raw materials were mixed in the weight percentages shown in FIG. 9, etc., kneaded and crushed, and then crushed into a predetermined ring shape at 150 kg / cm. ２ It is manufactured by hot pressing and then heat treating at 1000°C or higher.

[0067] Titanium (IV) oxide provides the functions of adding roughness and improving abrasion resistance.

[0068] (Materials) Pitch coke: particle size 10-40 μm Artificial graphite: particle size 10-40 μm Carbon black: particle size 19-60 nm Clay: particle size 2-30 μm Coconut shell activated carbon: particle size 2-30 μm Phenol resin TiO ２ : Particle size 2.10~2.55μm

[0069] (Functional Evaluation) Sliding parts were formed with various weight percentages, and functional evaluation was carried out on the formed sliding parts of Examples 31 to 44 together with the sliding parts of Comparative Examples 31 to 42. The evaluation items of the functions were the same as those of the first embodiment, but the evaluation criteria for the items "wear resistance (surface roughness after sliding)" and "absence of squeal" were stricter than those of the first embodiment.

[0070] (Examples 31 and 32) The results of the performance evaluation of Examples 31 and 32 and Comparative Examples 31 and 32 are summarized in the table of FIG.

[0071] In Examples 31 and 32 and Comparative Examples 31 and 32, the ratio of coke (pitch coke) to artificial graphite was different, and other materials such as carbon black (C.B.), kaolin clay, coconut shell activated carbon, phenolic resin carbide, titanium oxide (IV) (TiO ２ ) there is no relative difference in weight percentage.

[0072] As shown in Figure 9, Comparative Example 31, which contains 0 wt% artificial graphite and 55 wt% pitch coke, does not meet the criteria for "friction characteristics (friction coefficient during dry sliding of 0.3 or less)." In contrast, Example 31, which contains 1.2 wt% artificial graphite and 53.8 wt% pitch coke, meets the criteria for all items.

[0073] 9, Comparative Example 32, which contains 6 wt% artificial graphite and 49 wt% pitch coke, does not meet the criteria for "material characteristics (hardness) HSD 110 or more" and "friction characteristics (dry sliding friction coefficient 0.3 or less)." In contrast, Example 32, which contains 4.5 wt% artificial graphite and 50.5 wt% pitch coke, meets the criteria for all items. From this, it was found that the appropriate blending range of artificial graphite is more than 0 wt% and less than 6 wt%, preferably 1 wt% to 5 wt%, and more preferably 1.2 wt% to 4.5 wt%.

[0074] (Examples 33 and 34) The results of the performance evaluation of Examples 33 and 34 and Comparative Examples 33 and 34 are summarized in the table of FIG.

[0075] In Examples 33 and 34 and Comparative Examples 33 and 34, the blending ratio of pitch coke and carbon black (C.B.) was different, and other ingredients such as artificial graphite, kaolin clay, coconut shell activated carbon, phenolic resin, titanium oxide (IV) (TiO ２ There is no relative difference in the weight percentage of artificial graphite. All artificial graphite is 3 wt%, which conforms to the appropriate range of more than 0 wt% and less than 6 wt%.

[0076] 10, Comparative Example 33, which contains 0 wt% carbon black and 53 wt% pitch coke, does not meet the criteria for "material characteristics (hardness) HSD 110 or more" and "wear resistance (surface roughness after sliding)." In contrast, Example 33, which contains 0.2 wt% carbon black and 52.8 wt% pitch coke, meets the criteria for all items.

[0077] 10, Comparative Example 34, which contains 5 wt% carbon black and 48 wt% pitch coke, does not meet the criteria for "material characteristics (hardness) HSD 110 or more," "material characteristics (flexural strength) 80 MPa or more," and "wear resistance (surface roughness after sliding)." In contrast, Example 34, which contains 2.5 wt% carbon black and 50.5 wt% pitch coke, meets the criteria for all items. From this, it was found that the appropriate range of carbon black blending is more than 0 wt% and less than 5 wt%, preferably 0.1 wt% to 3 wt%, and more preferably 0.2 wt% to 2.5 wt%.

[0078] (Examples 35 and 36) The results of the performance evaluation of Examples 35 and 36 and Comparative Examples 35 and 36 are summarized in the table of FIG.

[0079] In Examples 35 and 36 and Comparative Examples 35 and 36, the weight percentages of pitch coke and kaolin clay were different, and other components such as artificial graphite, carbon black (C.B.), coconut shell activated carbon, phenolic resin, titanium oxide (IV) (TiO ２ There is no relative difference in the weight percentages of the other materials. All weight percentages except for kaolin clay are within the appropriate range, and all artificial graphites are 3 wt% and all carbon blacks are 1 wt%.

[0080] As shown in Figure 11, Comparative Example 35, which contains 3 wt% kaolin clay and 56 wt% pitch coke, does not meet the criteria for "cracks caused by firing," "friction characteristics (friction coefficient of 0.3 or less during dry sliding)," and "wear resistance (surface roughness after sliding)." In contrast, Example 35, which contains 5 wt% kaolin clay and 54 wt% pitch coke, meets the criteria for all items.

[0081] 11, Comparative Example 36, which contains 12 wt% kaolin clay and 47 wt% pitch coke, does not meet the criteria for "material properties (hardness) HSD 110 or more" and "friction properties (dry sliding friction coefficient 0.3 or less)." In contrast, Example 36, which contains 9 wt% kaolin clay and 50 wt% pitch coke, meets the criteria for all items. From this, it was found that the appropriate blending range of kaolin clay is more than 3 wt% and less than 12 wt%, preferably 4 wt% to 10 wt%, and more preferably 5 wt% to 9 wt%.

[0082] (Examples 37 and 38) The results of the performance evaluation of Examples 37 and 38 and Comparative Examples 37 and 38 are summarized in the table of FIG.

[0083] In Examples 37 and 38 and Comparative Examples 37 and 38, the weight percentages of pitch coke and coconut shell activated carbon were different, and other materials such as artificial graphite, carbon black (C.B.), kaolin clay, phenolic resin, titanium oxide (IV) (TiO ２ There is no relative difference in the weight percentages of the ingredients. All of the weight percentages except for coconut shell activated carbon are within the appropriate ranges: all of the artificial graphite is 3 wt%, all of the carbon black is 1 wt%, and all of the kaolin clay is 7 wt%.

[0084] As shown in FIG. 12, in Comparative Example 37 in which the coconut shell activated carbon was 0 wt % and the pitch coke was 62 wt %, the "material property (linear expansion coefficient) 2.0 × 10 －６ It is found that the criteria for "friction characteristics (friction coefficient of 0.3 or less during dry sliding)" and "wear resistance (surface roughness after sliding)" are not met. Furthermore, it is found that the criteria for "no squealing" in relative sliding with the rotating ring are not met. In contrast, Example 37, which contains 8 wt% coconut shell activated carbon and 54 wt% pitch coke, meets the criteria for all items.

[0085] 12, Comparative Example 38, which contains 20 wt% coconut shell activated carbon and 42 wt% pitch coke, does not meet the criteria for "cracks during firing," "friction characteristics (friction coefficient of 0.3 or less during dry sliding)," and "friction characteristics (heat generation of 60°C or less during dry sliding)." In contrast, Example 38, which contains 13 wt% coconut shell activated carbon and 49 wt% pitch coke, meets the criteria for all items. From this, it was found that the coconut shell activated carbon should be blended in a range of more than 0 wt% and less than 20 wt%, preferably 2 wt% to 15 wt%, and more preferably 8 wt% to 13 wt%.

[0086] Although not shown directly, titanium oxide (IV) (TiO ２ Three samples were prepared by adding 2 wt% of the slag and reducing the pitch coke by 2 wt%, and were subjected to functional and basic evaluations. These three samples met the criteria for all items in the functional evaluation. In addition, the basic evaluation results were almost the same as those of Examples 21 to 23.

[0087] (Examples 39 to 41) The results of the performance evaluation of Examples 39 to 41 and Comparative Examples 39 and 40 are summarized in the table of FIG.

[0088] In Examples 39 to 41 and Comparative Examples 39 and 40, the weight percentages of pitch coke and phenolic resin were different, and other materials such as artificial graphite, carbon black (C.B.), kaolin clay, coconut shell activated carbon, titanium oxide (IV) (TiO ２ There is no relative difference in the weight percentages of the ingredients. The weight percentages of all ingredients except for the phenolic resin are within the appropriate ranges: all artificial graphite is 3 wt%, all carbon black is 1 wt%, all kaolin clay is 7 wt%, and all coconut shell activated carbon is 10 wt%.

[0089] As shown in FIG. 13, in Comparative Example 39 in which the phenolic resin was 10 wt % and the pitch coke was 67 wt %, the "product feasibility (moldability after mixing)" and "material properties (linear expansion coefficient) 2.0×10 －６It is found that the standard for "1 / K or less" is not met. In addition, the condition for moldability after mixing is not met, and a sliding test using a testing device has not been conducted, so other items have not been evaluated. In contrast, Example 39, which contains 20 wt% phenolic resin and 57 wt% pitch coke, meets the standards for all items.

[0090] 13, Comparative Example 40, which contains 50 wt% phenolic resin and 27 wt% pitch coke, does not meet the criteria for "fire cracking," "material characteristics (hardness) HSD 110 or more," "friction characteristics (dry sliding friction coefficient 0.3 or less)," "friction characteristics (dry sliding heat generation 60°C or less)," and "wear resistance (surface roughness after sliding)." Furthermore, it does not meet the criteria for "leakage (leakage amount 10 mL / 100 h or less)" and "no squeal" during relative sliding with the rotating ring. In contrast, Example 41, which contains 40 wt% phenolic resin and 37 wt% pitch coke, meets the criteria for all items.

[0091] 13, Example 40, which contains 30 wt% phenolic resin and 47 wt% pitch coke, and is intermediate between Example 39 and Example 41, satisfies all the criteria. This indicates that the phenolic resin should be blended in a range of more than 10 wt% and less than 50 wt%, preferably 15 wt% to 45 wt%, and more preferably 20 wt% to 40 wt%.

[0092] As shown in Figure 14, four Examples 51 to 54 were prepared using the weight percentages of the materials that passed the performance evaluations described above and the titanium dioxide (IV) test described below. Examples 51 to 54 differ in the weight percentages of pitch coke and phenolic resin, with no relative differences in the weight percentages of the other ingredients: artificial graphite, carbon black (C.B.), kaolin clay, coconut shell activated carbon, and titanium dioxide (IV). Example 51 had the lowest weight percentage of phenolic resin, while Example 54 had the highest weight percentage of phenolic resin. Examples 51 to 54 met the criteria for all items in the performance evaluation.

[0093] The results of the basic evaluation of Examples 51 to 54 and the conventional comparative example 21 are summarized in the table of FIG.

[0094] 15, Examples 51 to 54 have values ​​equivalent to those of Comparative Example 21 for the coefficient of friction and hardness HSD, but are dramatically improved in bending strength MPa compared to Comparative Example 21. Furthermore, the values ​​of wear depth μm for Examples 51 to 54 are significantly reduced compared to Comparative Example 21. Thus, it was found that the sliding parts of Examples 51 to 54 satisfy the required standards for the coefficient of friction, i.e., lubricity and mechanical properties, and also have dramatically improved wear resistance compared to Comparative Example 21.

[0095] (Examples 42 to 44) The results of the performance evaluation of Examples 42 to 44 and Comparative Examples 41 and 42 are summarized in the table of FIG.

[0096] In Examples 42 to 44 and Comparative Examples 41 and 42, pitch coke and titanium oxide (IV) (TiO ２ ), but there is no relative difference in the weight percentages of the other materials, such as artificial graphite, carbon black (C.B.), kaolin clay, coconut shell activated carbon, and phenolic resin. Except for titanium (IV) oxide, the weight percentages of all materials are within the appropriate range: artificial graphite is 3 wt%, carbon black is 1 wt%, kaolin clay is 7 wt%, coconut shell activated carbon is 10 wt%, and phenolic resin is 25%.

[0097] As shown in Figure 16, Comparative Example 41, which contains 0 wt% titanium dioxide (IV) and 54 wt% pitch coke, does not meet the criteria for "wear resistance (surface roughness after sliding)." Furthermore, it does not meet the criteria for "no squealing" during relative sliding with the rotating ring. In contrast, Example 42, which contains 2 wt% titanium dioxide (IV) and 52 wt% pitch coke, meets the criteria for all items.

[0098] 16, Comparative Example 42, which contains 8 wt% titanium dioxide (IV) and 46 wt% pitch coke, does not meet the criteria for "friction characteristics (friction coefficient of 0.3 or less during dry sliding)," "friction characteristics (heat generation of 60°C or less during dry sliding)," and "wear resistance (surface roughness after sliding)." Furthermore, it does not meet the criteria for "leakage (leakage amount of 10 mL / 100 h or less)" during relative sliding with the rotating ring. In contrast, Example 44, which contains 6 wt% titanium dioxide (IV) and 48 wt% pitch coke, meets the criteria for all items.

[0099] 16, Example 43, which contains 4 wt% titanium dioxide (IV) and 50 wt% pitch coke, and is intermediate between Example 42 and Example 44, meets all the criteria. This indicates that the appropriate range for titanium dioxide (IV) is more than 0 wt% and less than 8 wt%, preferably 1 wt% or more and 7 wt% or less, and more preferably 2 wt% or more and 6 wt% or less.

[0100] As shown in Figure 17, two examples, Examples 55 and 56, were prepared using the same weight percentages of the materials that passed the performance evaluation. Examples 51 to 54 differ in the weight percentages of pitch coke and titanium dioxide (IV), with no relative differences in the weight percentages of the other ingredients: artificial graphite, carbon black (C.B.), kaolin clay, coconut shell activated carbon, and phenolic resin. Example 55 had the lowest weight percentage of titanium dioxide (IV), while Example 56 had the highest weight percentage of titanium dioxide (IV). Examples 55 and 56 met all criteria in the performance evaluation.

[0101] The results of the basic evaluation of Examples 55 and 56 and the conventional comparative example 21 are summarized in the table of FIG.

[0102] 18, Examples 55 and 56 have values ​​for the friction coefficient and hardness HSD that are equivalent to those of Comparative Example 21, but have a significantly improved bending strength MPa compared to Comparative Example 21. Furthermore, the wear depth μm values ​​of Examples 55 and 56 are significantly reduced compared to Comparative Example 21. In this way, it was found that the sliding parts of Examples 51 to 54 satisfy the required standards for the friction coefficient, that is, lubricity and mechanical properties, and also have a significantly improved wear resistance compared to Comparative Example 21.

[0103] From the above-mentioned functional evaluation, it was found that the adhesive wear resistance of sliding parts can be improved by manufacturing sliding parts with a blend of more than 0 wt % and less than 8 wt % of high-grade titanium (IV) oxide. As a result, it is possible to prevent the sliding surfaces from becoming mirror-finished due to adhesive wear more effectively than in the first embodiment, and to maintain the relative roughness between the sliding surfaces.

[0104] In addition, by including phenolic resin in an amount of 20 wt % or more and 35 wt % or less, the interparticle distance of the compounded materials other than the phenolic resin is increased, ensuring roughness and reducing the occurrence of squealing.

[0105] In addition, by containing more than 0 wt% and less than 6 wt% artificial graphite, more than 0 wt% and less than 5 wt% carbon black, more than 3 wt% and less than 12 wt% kaolin clay, more than 0 wt% and less than 20 wt% coconut shell activated carbon, more than 10 wt% and less than 50 wt% phenolic resin, more than 0 wt% and less than 8 wt% titanium oxide (IV), with the remainder being pitch coke, it was possible to effectively increase mechanical strength and improve adhesive wear resistance.

[0106] From the viewpoint of expecting further improvements in mechanical strength and adhesive wear resistance, the composite material contains 1 wt% to 5 wt% of artificial graphite, 0.1 wt% to 3 wt% of carbon black, 4 wt% to 10 wt% of kaolin clay, 2 wt% to 15 wt% of coconut shell activated carbon, 15 wt% to 45 wt% of phenolic resin, 1 wt% to 7 wt% of titanium oxide (IV), and the balance is pitch coke. It is preferable that the composition of the sintered product is 1.2 wt% to 4.5 wt% of artificial graphite, 0.2 wt% to 2.5 wt% of carbon black, 5 wt% to 9 wt% of kaolin clay, 8 wt% to 13 wt% of coconut shell activated carbon, 20 wt% to 40 wt% of phenolic resin, 2 wt% to 6 wt% of titanium (IV) oxide, and the remainder is pitch coke. It is also preferable that the sintered product contains about 0.5 wt% of unavoidable impurities.

[0107] Although the embodiments of the present invention have been described above with reference to the drawings, the specific configuration is not limited to these embodiments, and the present invention also includes modifications and additions that do not deviate from the gist of the present invention.

[0108] For example, in the first and second embodiments, a mechanical seal for general industrial machinery has been described as an example of the use of the sliding component, but the present invention may also be applied to other mechanical seals for automobiles, water pumps, etc. Furthermore, the present invention is not limited to mechanical seals, and may also be applied to sliding components other than mechanical seals, such as plain bearings.

[0109] Furthermore, the coke used as the main component of the carbonaceous material of the sliding parts is not limited to pitch coke, but may be calcine coke or coal coke, for example.

[0110] Furthermore, the clay used as an additive is not limited to kaolin clay, but may be, for example, pyrophyllite clay.

[0111] Furthermore, the activated carbon is not limited to coconut shell activated carbon, but may be, for example, coal-based activated carbon.

[0112] Furthermore, the resin used as the binder is not limited to phenol resin, but may be, for example, polyphenylene sulfide.

[0113] The metal oxide used as an additive is titanium oxide (IV) (TiO ２ ), but is not limited to silicon dioxide (SiO ２ ), and zirconia (ZrO ２ ), and cerium (IV) oxide (CeO ２ ) and may be changed as appropriate.

[0114] 10 Testing device 11 Fixed ring (sliding part) 12 Holding mechanism 13 Rotating ring 14 Rotating shaft

Claims

1. A sliding part having a sliding surface that slides relative to one another, the sliding part including coke and graphite as carbonaceous materials, and a resin carbide, the graphite being more than 0 wt% and less than 6 wt%, and the coke constituting the main component of the carbonaceous material.

2. A sliding part according to claim 1, containing 30 wt % or more of the coke.

3. The sliding part according to claim 1, containing more than 0 wt % and less than 5 wt % of carbon black as the carbonaceous material.

4. The sliding part according to claim 1, containing more than 3 wt % and less than 12 wt % of clay as an additive.

5. A sliding part according to claim 1, containing activated carbon as the carbonaceous material in an amount of more than 0 wt % and less than 20 wt %.

6. The sliding part according to claim 1, containing more than 10 wt % and less than 50 wt % of the resin carbide.

7. The sliding part according to claim 6, wherein the resin carbide is a phenol resin carbide.

8. The sliding part according to claim 1, containing more than 0 wt % and less than 8 wt % of a metal oxide as an additive.

9. A sliding part according to claim 1, comprising at least 1 wt% and less than 6 wt% of graphite, more than 0 wt% and less than 5 wt% of carbon black, more than 3 wt% and less than 12 wt% of clay, more than 0 wt% and less than 20 wt% of activated carbon, more than 10 wt% and less than 50 wt% of the resin carbide, and the remainder consisting of the coke.

10. A sliding part according to claim 1, comprising at least 1 wt% and less than 6 wt% of graphite, more than 0 wt% and less than 5 wt% of carbon black, more than 3 wt% and less than 12 wt% of clay, more than 0 wt% and less than 20 wt% of activated carbon, more than 10 wt% and less than 50 wt% of the resin carbide, more than 0 wt% and less than 8 wt% of the metal oxide, with the remainder being the coke.

11. A sliding part according to any one of claims 1 to 10, wherein the sliding surface layer of the sliding part is not impregnated with resin.

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