JP2007239867A - Sliding bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve foreign matter embedding performance, in its turn, to improve non-seizure performance, in a sliding bearing provided with a resin covering layer. <P>SOLUTION: The resin covering layer 3 is arranged on a surface of a bearing alloy 2 constituting a base material, and comprises a base resin 4 being a binder, a massive soft material 6 composed of elastomer and/or rubber being a soft high polymer substance softer than the base resin 4 and forming a massive shape having an average particle size of 10 μm or more, and a solid lubricant arranged in the base resin 4. The massive soft material 6 exhibits the action of embedding foreign matter entering between the resin covering layer 3 being a sliding surface and a mating material. Thus, the foreign matter embedding performance can be improved, and in its turn, the non-seizure performance can be improved. Soft metal 5 is also preferably added to the resin covering layer 3. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a plain bearing having a structure in which a resin coating layer is provided on the surface of a base material.

For example, in a sliding bearing for an automobile engine, a copper-based bearing alloy or an aluminum-based bearing alloy is joined on a steel plate back metal, and a resin coating layer mainly composed of a synthetic resin is provided on the surface of the bearing alloy. It is. And in order to improve abrasion resistance and non-seizure property, what made the resin coating layer provide a solid lubricant and a soft metal particle is proposed (for example, refer patent documents 1 and 2).
JP 2002-242933 A JP 2000-240657 A

  By the way, when using a sliding bearing, foreign matters such as iron powder may enter between the sliding surface of the bearing and the mating material, and seizure may occur due to this. In a conventional bearing, a resin coating layer is provided on the sliding surface. However, there is a problem that the resin coating layer has a poor foreign material burying property, and thus there is a problem that non-seizure property is lowered.

  The present invention has been made in view of the above-described circumstances, and the object of the present invention is to improve the foreign matter embedding property and to improve the non-seizure property in the case where the resin coating layer is provided. To provide a plain bearing that can.

  In order to achieve the above-described object, the invention according to claim 1 is a sliding bearing in which a resin coating layer is provided on a surface of a base material, wherein the resin coating layer includes a base resin serving as a binder, a solid lubricant, A soft polymer substance that does not dissolve in the base resin and is softer than the base resin, is composed of an elastomer and / or rubber, and has a bulky soft material that forms a bulky shape having an average particle diameter of 10 μm or more. Features.

The resin coating layer is a soft polymer material that is softer than the base resin and includes a lump soft material made of elastomer and / or rubber, so that foreign matter has entered between the resin coating layer that becomes the sliding surface and the counterpart material. At the same time, the lump soft material exerts an effect of burying the foreign matter. Therefore, the foreign substance burying property can be improved, and as a result, non-seizure property can be improved. By setting the average particle size of the lump soft material to 10 μm or more, the foreign substance embedding property can be effectively exhibited. Even if a lump soft material exists in the resin coating layer, it is difficult to obtain a foreign substance embedding effect when the average particle diameter is less than 10 μm. Here, the average particle diameter of a lump soft material means the average value of the dimension of the length direction of each lump soft material.
The resin coating layer includes a solid lubricant. The solid lubricant has an effect of improving lubricity and has an effect of further improving wear resistance and non-seizure property.

Here, as the base material of the slide bearing, a known material such as a copper-based bearing alloy, an aluminum-based bearing alloy, steel, or stainless steel can be used, and can be appropriately selected according to the purpose.
As the base resin of the resin coating layer, either one or both of a thermosetting resin and a thermoplastic resin may be used. Examples of the thermosetting resin include polyimide (PI), epoxy (EP), polyamideimide (PAI), and phenol (PF) resin. Examples of the thermoplastic resin include polybenzimidazole (PBI), polyphenylene sulfide (PPS), polyamide (PA), and polyether ether ketone (PEEK) resin.

Examples of elastomers constituting the bulk soft material include styrene elastomers, polyester elastomers, urethane elastomers, fluorine elastomers, ethylene elastomers, olefin elastomers, and polyamide elastomers, and one or more of these are selected. And use.
Examples of the rubber constituting the bulk soft material include silicone rubber, fluorine rubber, styrene / butadiene rubber, and styrene rubber. One or more of these are selected and used.
Examples of the solid lubricant include MoS ₂ , polytetrafluoroethylene, graphite, WS ₂ , CF ₄ , and BN, and one or more of these are selected and used.
As thickness (film thickness) of a resin coating layer, 5-50 micrometers is preferable, More preferably, it is 10-30 micrometers.

  In the resin coating layer, the proportion of the lump soft material is preferably set to 10 to 50 vol%. By setting it to 10 vol% or more, the effect of foreign material embedding improves, and by setting it to 50 vol% or less, good wear resistance can be maintained.

It is also preferable to include a soft metal in the resin coating layer. Examples of the soft metal include Sn, Pb, Bi, In, Ag, Cu, and alloys thereof, and one or more of these are selected and used. These soft metals have the effect of improving lubricity and also have high thermal conductivity, and therefore have the effect of further improving wear resistance and non-seizure properties.
In the resin coating layer, it is preferable that the ratio of the lump soft material and the soft metal is also set to 10 to 50 vol%. The effect of foreign matter embedding is improved by setting the proportion of these to 10 vol% or more, and good wear resistance can be maintained by setting the ratio to 50 vol% or less.

The durometer A preferably has a durometer A hardness of 98 or less, more preferably 40 or less. The lower the durometer A value, the softer. The softer the lump soft material, the better the foreign substance embedding effect.
The proportion of the solid lubricant in the resin coating layer is preferably set to 5 to 60 vol%. By setting it to 5 vol% or more, the effect of the solid lubricant can be expected. By setting it to 60 vol% or less, good wear resistance can be maintained.

  Hereinafter, the present invention will be described in detail based on examples and comparative examples. First, a test piece was prepared as follows. A plate-like aluminum alloy plate serving as a bearing alloy layer was placed on the steel plate serving as the back metal layer, and the bimetals were obtained by sandwiching them and joining them between rollers. The total thickness of the obtained bimetal was 1.5 mm. A test piece was prepared from the bimetal thus obtained. As the bearing alloy layer, an aluminum alloy is used as described above, but a copper alloy may be used. In Table 1, Al described in the column of the bearing alloy layer indicates an aluminum alloy.

  The test piece thus prepared was subjected to blasting and degreasing pretreatment, and then a resin coating layer was provided on the surface of the bearing alloy layer by spray coating the following resin liquid. The coating thickness (film thickness) at this time was 25 μm. As the base resin of the resin liquid for coating, PAI which is a thermosetting resin and PBI which is a thermoplastic resin were selected. The resin liquid for coating was mixed with a solid lubricant, a soft metal, and an elastomer and / or rubber for forming a lump soft material. When mixing, the elastomer and rubber are in liquid form.

Here, MoS ₂ and PTFE were selected as the solid lubricant. As the soft metal, an Sn-based alloy and a Pb-based alloy were selected. As the elastomer, a fluorine elastomer and a polyester elastomer were selected. A fluoroelastomer having a durometer A representing a hardness in a cured state of 48 was used. A polyester elastomer having a durometer A of 98 was used. Silicone rubber was selected as the rubber. The silicone rubber having a durometer A of 88 was used. Table 1 shows the blending ratio of the used base resin, solid lubricant, soft metal, elastomer, and rubber. In Table 1, polyester elastomer was used as the elastomer of Example 4, and fluoroelastomer was used as the elastomer of Examples other than Example 4.

  After the coating with the resin liquid was dried at 100 ° C., it was fired at 180 to 250 ° C. Thereby, the resin coating layer provided with the lump soft material which consists of an elastomer and / or rubber | gum is formed in the bearing alloy layer surface. At this time, by controlling the temperature and time of drying and baking, the average particle diameter of the aggregate of the elastomer and rubber (bulk soft material) can be controlled.

FIG. 1 is a schematic view showing an example of the bearing of the present invention prepared as described above. In FIG. 1, 1 is a back metal layer, 2 is a bearing alloy layer as a base material, 3 is a resin coating layer, 4 is a base resin containing a solid lubricant (not shown), 5 is a soft metal, 6 is an elastomer and / or It is a lump soft material composed of rubber aggregates.
In Comparative Examples 1 to 5, in Comparative Examples 1 to 3, neither a soft metal nor an elastomer or rubber for forming a lump soft material is mixed in the resin liquid to be coated. In Comparative Examples 4 and 5, the elastomer (fluoroelastomer) is mixed in the resin liquid to be coated, but the average particle size when it becomes an aggregate (bulky soft product) is 5 μm.

  About each Example and comparative example of the obtained test piece, the baking test and the abrasion test were done. The seizure test was performed under the test conditions shown in Table 2. In this case, foreign matter was mixed in the supplied oil. The foreign matter corresponds to the second type of JIS Z 8901, and the median diameter range is 27 to 31 μm. Then, the surface pressure was increased by 1 MPa every 10 minutes, and it was determined that seizure occurred when the bearing back surface temperature reached 180 ° C. or higher. The results are shown in Table 1. Further, the wear test was performed under the test conditions shown in Table 3, and the amount of wear was measured. The results are also shown in Table 1.

From the test results shown in Table 1, the following can be understood.
First, Comparative Examples 2 and 3 and Examples 2 to 7 are compared. In Comparative Examples 2 and 3 in which the resin coating layer was not provided with a lump soft material (elastomer or rubber), the stoving load was 9 MPa or less. On the other hand, in Examples 2 to 7 in which the resin coating layer is provided with a lump soft material (elastomer, rubber), the seizure load is 13 MPa or more, and the non-seizure property is superior to Comparative Examples 2 and 3. I understand. This is because, when the resin coating layer is only the base resin and the solid lubricant as in Comparative Examples 2 and 3, when a foreign material enters between the bearing and the counterpart material, the foreign material is buried in the resin coating layer. As a result, the seizure load is considered to be low. On the other hand, if the resin coating layer has a lump soft material made of elastomer or rubber as in Examples 2 to 7, foreign matter is easily buried by the lump soft material, and as a result, the seizure load Will be higher. When Comparative Example 1 and Example 15 are compared, the same results are obtained.

  Comparative Example 4 and Example 2 are compared. Both Comparative Example 4 and Example 2 had 10 vol% of a lump soft material made of an elastomer in the resin coating layer, but the seizure load of Comparative Example 4 was 9 MPa, and Example 2 was 13 MPa. In the case of the comparative example 4, since the average particle diameter of a lump soft material is as small as 5 micrometers, it is thought that the foreign material embedding effect is low and the seizing load is also low. On the other hand, in the case of Example 2, the average particle diameter of the lump soft material is 10 μm, which is larger than that in Comparative Example 4. For this reason, it is considered that the effect of embedding foreign matter by the lump soft material is increased, and as a result, the seizure load is increased. When the comparative example 5 is compared with the examples 15 and 16, it is understood that the same is true.

  Consider Examples 1-16 in more detail. When Examples 2 to 7 and Examples 8 to 13 and 16 are compared with each other, Examples 8 to 13 and 16 containing a soft metal have a seizing load compared to Examples 2 to 7 not containing a soft metal. Is relatively high, and inclusion of a soft metal tends to improve non-seizure properties.

  Examples 2-7 and 15 are examples which do not contain a soft metal. When these are seen, it is thought that 10-50 vol% is preferable for the ratio for which a lump soft thing accounts. Moreover, Examples 1, 8-14, and 16 are examples containing both a soft metal and a lump soft material. When these are seen, it is thought that 10-50 vol% is preferable for the ratio which combined these soft metals and lump soft materials. When the proportion of the soft metal or the lump soft material exceeds 50 vol%, the amount of wear tends to increase and the seizure load tends to decrease.

  Moreover, in Examples 1-16, when the ratio for which a lump soft thing accounts increases, and when the ratio which combines a lump soft substance and a soft metal increases, there exists a tendency for an abrasion amount to increase. In consideration of the amount of wear and the seizure load, when the soft metal is not included, the proportion of the bulk soft material is preferably 10 to 50 vol%. When the soft metal is included, the soft metal and the bulk soft material are included. Is preferably 10 to 50 vol%.

The present invention is not limited to the above-described embodiments, and can be modified or expanded as follows.
As a method for forming the resin coating layer, in addition to spray coating, pad printing, screen printing, roll coating, dispenser, and the like are also possible.

Sectional drawing which showed the Example of this invention typically

Explanation of symbols

  In the drawings, 1 is a back metal layer, 2 is a bearing alloy layer (base material), 3 is a resin coating layer, 4 is a base resin (including a solid lubricant), 5 is a soft metal, and 6 is a lump soft material.

Claims (7)

In slide bearings with a resin coating on the surface of the substrate,
The resin coating layer is
A base resin as a binder;
A lump soft material that is a soft polymer substance that does not dissolve in the base resin and is softer than the base resin, and is made of an elastomer and / or rubber, and has a lump with an average particle diameter of 10 μm or more;
A plain bearing characterized by comprising a solid lubricant.   The sliding bearing according to claim 1, wherein a ratio of the bulk soft material in the resin coating layer is 10 to 50 vol%.   The resin coating layer includes a soft metal, and the soft metal is at least one selected from Sn, Pb, Bi, In, Ag, Cu, and alloys thereof. Or the plain bearing of 2.   4. The plain bearing according to claim 3, wherein a ratio of the bulk soft material and the soft metal in the resin coating layer is 10 to 50 vol%.   5. The plain bearing according to claim 1, wherein a durometer A has a durometer A of 98 or less in hardness.   The sliding bearing according to any one of claims 1 to 5, wherein a ratio of the solid lubricant in the resin coating layer is 5 to 60 vol%. The base resin is composed of one or more selected from polyimide, epoxy, polyamideimide, phenol, polybenzimidazole, polyphenylene sulfide, polyamide, polyetheretherketone, and the elastomer is a styrene elastomer, a polyester elastomer, It consists of one or more selected from urethane elastomers, fluorine elastomers, ethylene elastomers, olefin elastomers, and polyamide elastomers. The rubber is silicone rubber, fluorine rubber, styrene / butadiene rubber, or styrene rubber. consists of one or more selected from, the solid lubricant, MoS _2, polytetrafluoroethylene, graphite, this consisting of WS _2, CF 4, one or more selected from among _BN Sliding bearing according to any one of claims 1 to 6, wherein.

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