Plain bearing system, compressor

Abstract

The application provides a sliding bearing system and a compressor. The sliding bearing system comprises a high-silicon aluminum alloy sliding bearing and a nodular cast iron crankshaft which are mutually abraded, and a low-viscosity lubricating oil with an adsorption additive is filled between the sliding bearing and the crankshaft; the high-silicon aluminum alloy contains 10.1-25.5 wt.% of silicon, and the adsorption additive comprises one or more of a hydroxyl polymer, a phosphate ester polymer, an amine phosphate polymer, a phenol and a phosphonitrile polymer. The sliding bearing system can reduce the risk of adhesive wear of the same material, improve the long-term wear resistance of the sliding bearing, the adsorption additive can form a chemical adsorption oil film on the surface of the high-silicon aluminum alloy, and the lubricating effect is significantly improved; the sliding bearing system can have good wear resistance and lubricating performance, the sliding friction power consumption is low, and the performance of the compressor using the sliding bearing system can be greatly improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of compressor, in particular to a sliding bearing system and a compressor. BACKGROUND

[0002] For the compressor, the friction power consumption between the crankshaft in the compressor and its corresponding friction pairs accounts for 4-8% of the total power consumption of the compressor. The existing conventional scheme adopts high-viscosity lubricating oil to improve the lubricating performance between the nodular cast iron crankshaft and the gray cast iron bearing part, thereby reducing the friction power consumption. The graphite in the nodular cast iron and the gray cast iron can also play a certain role in reducing the friction power consumption, but the lubricating performance achieved by only combining the lubricating oil and the graphite cannot meet the high-efficiency requirements of the compressor. Moreover, the base materials of the nodular cast iron and the gray cast iron are mainly pearlite and ferrite except for the graphite form, and the crystal lattice structures of the same materials are the same, and the compatibility is high, which may have the risk of adhesive wear. With the gradual development of the piston compressor towards high efficiency, higher requirements are put forward for the performance of the compressor, especially the requirement for reducing the power consumption of the compressor under the low-frequency and low-speed working condition for a long time. The existing conventional scheme of the crankshaft in the compressor and other friction pairs and the lubricating oil in the compressor cannot meet the requirement of further reducing the operating power consumption of the compressor. At the same time, mechanical noise may be generated between the crankshaft in the compressor and its corresponding friction pairs due to friction, thereby causing the operating noise of the whole compressor to increase. The increased noise may seriously affect the user experience.

[0003] Chinese patent authorized publication No. CN 101180472 B discloses a sliding bearing composite material. The composite sliding bearing is composed of a steel support layer, an aluminum alloy (containing 1.0-3.0 wt.% Ni, 0.5-2.5 wt.% Mn, 0.02-1.5 wt.% Cu, and the balance of Al) intermediate layer, and an aluminum alloy (containing 1.0-3.0 wt.% Ni, 0.5-2.5 wt.% Mn, 0.02-1.5 wt.% Cu, and the balance of Al) surface layer. The sliding bearing is formed in one casting system to reduce the cost while ensuring the fatigue strength, wear resistance, and corrosion resistance of the sliding bearing. However, the composite structure has a high overall production cost, and the base has few support and wear-resistant phases, which cannot meet the long-term wear resistance requirements of the sliding bearing.

[0004] Chinese patent authorization publication number CN 102869800 B discloses a bearing device, which is composed of a steel support layer with a surface hardness of 500HV or more and an aluminum alloy surface layer with a hardness of 50HV or more (containing 2-10wt. % Si, 8-18wt. % Sn, 3wt. % or less Cu / Mg / Zn, at least one of 0.5wt. % or less Cr / Zr / Mn / V / Sc), thereby improving the wear resistance of the composite sliding bearing under harsh sliding conditions. However, it is a double-layer composite structure, which leads to increased production cost.

[0005] Chinese patent publication number CN 112567188 A discloses a refrigerant compressor and an apparatus using the same, which uses a refrigerant oil to which an oil film loss adjusting agent is added, the agent being in a dissolved state and not being precipitated during operation of the compressor, one sliding member of a sliding surface is made of an iron-based material, and the other sliding member is made of at least one non-iron-based material of an aluminum alloy, a magnesium alloy, and a resin material, the kinematic viscosity of the refrigerant oil at 40°C is 4.9mm 2 / s or less, the refrigerant is at least one of R600a, R290, and R744, and further, in the case of low-speed operation of the compressor using low-viscosity refrigerant oil, the problem of reduction in sealing performance due to oil film loss between the piston and the cylinder can be prevented, and the problem of reduction in compressor efficiency due to reduction in cooling capacity of the refrigerant compressor due to oil film loss can also be prevented. However, it is a general-purpose oil film loss adjusting agent, which cannot make the oil film on the surface of the non-iron-based part into a chemical bond with better binding force, and cannot guarantee the wear resistance of the non-iron-based material itself, and it only considers improving the lubricating performance between the piston and the cylinder, and does not consider improving the lubricating performance between the crankshaft and the bearing part. SUMMARY

[0006] The main purpose of the present application is to provide a sliding bearing system and a compressor to solve the problem of the existing technology that the bearing part of the compressor cannot balance the wear resistance and lubricating performance, and the sliding friction power consumption is large.

[0007] In order to achieve the above-mentioned purpose, according to one aspect of the present application, a sliding bearing system is provided, which comprises a sliding bearing and a crankshaft that are mutually abraded, and low-viscosity lubricating oil is filled between the sliding bearing and the crankshaft, wherein the material of the sliding bearing is high-silicon aluminum alloy, the weight percentage of silicon in the high-silicon aluminum alloy is 10.1-25.5wt. %; the material of the crankshaft is nodular cast iron; and the low-viscosity lubricating oil comprises an adsorbing additive, the adsorbing additive comprises one or more of a hydroxyl polymer, a phosphate ester polymer, an amine phosphate polymer, a phenol, and a phosphazene polymer.

[0008] Further, the weight percentage of silicon in the high-silicon aluminum alloy is 17-19wt. %; and / or the hardness HAl be 105-240 HBW; and / or the yield strength of the high-silicon aluminum alloy is ≥ 300 MPa.

[0009] Further, the hardness H Fe of the spheroidal graphite cast iron is 160-360 HBW.

[0010] Further, in the low-viscosity lubricating oil, the weight percentage of the adsorption additive is 0.5-6.0 wt.%.

[0011] Further, in the adsorption additive, the hydroxyl polymer includes one or more of a fatty diol, a cyclic diol, and a phenyl-substituted fatty diol; and / or the phosphate ester polymer includes one or more of a tricresyl phosphate, a triethyl phosphate, a butylene glycol phosphite, an alkyl phosphate, an alkyl phosphite, and an aryl phosphate; and / or the phosphorus amine polymer includes one or more of a phosphorus amine, a phosphoramide, a dialkyldithiophosphate amine, and a dialkyldithiophosphate amine.

[0012] Further, the kinematic viscosity of the low-viscosity lubricating oil at 40°C is 4.0-10.0 mm 2 / s; preferably, a mixed medium of the low-viscosity lubricating oil mixed with the refrigerant is filled between the sliding bearing and the crankshaft, and the kinematic viscosity of the mixed medium is 1.0-7.0 mm 2 / s.

[0013] Further, the fit clearance N between the sliding bearing and the crankshaft satisfies the formula (1):

[0014] (2tα1+α2D)ΔT < N ≤ (2tα1+α2D)ΔT + n (1),

[0015] wherein α1 is the linear expansion coefficient of the sliding bearing, α2 is the linear expansion coefficient of the crankshaft, t is the wall thickness of the sliding bearing, D is the diameter of the crankshaft, ΔT is the absolute value of the difference between the normal temperature and the working temperature of the sliding bearing, and n is the reserved clearance between the sliding bearing and the crankshaft.

[0016] Further, n is 0.0002-0.0050 mm.

[0017] According to another aspect of the present application, a compressor is provided, which includes the sliding bearing system of the present application.

[0018] Further, the compressor is a piston compressor, a rotor compressor, a vane compressor, a scroll compressor, a screw compressor, a positive displacement compressor, or a centrifugal compressor.

[0019] The application has the following advantages: first, the high-silicon aluminum alloy is used as the material of the sliding bearing, and the spheroidal graphite cast iron is used as the material of the crankshaft, so that the materials of the sliding bearing and the crankshaft are inconsistent, the risk of adhesion wear of the same material is reduced, and the hard silicon phase in the high-silicon aluminum alloy base can improve the long-term wear resistance of the sliding bearing; second, the specific adsorption additive is added in the low-viscosity lubricating oil, the specific adsorption additive can chemically react with the surface of the high-silicon aluminum alloy to form a chemical adsorption oil film, the chemical adsorption oil film can be adsorbed on the surface of the friction pair composed of the sliding bearing and the crankshaft by a chemical bond, the adsorption force and the carrying capacity are stronger, and the friction coefficient is lower than that of the physical adsorption oil film formed by the van der Waals force, so that the lubricating effect can be significantly improved; third, the soft phase alpha-Al of the high-silicon aluminum alloy sliding bearing base has similar lubricating behavior as the high-viscosity fluid, the graphite in the spheroidal graphite cast iron crankshaft also has a certain lubricating effect, and the low-viscosity lubricating oil containing the specific adsorption additive can form mixed lubrication on the basis of the lubricating properties of the lubricating oil itself and the stable chemical adsorption oil film on the surface of the aluminum alloy, and the three can cooperate to effectively reduce the sliding friction power consumption between the crankshaft and the sliding bearing. In summary, the sliding bearing system has good wear resistance and lubricating performance, the sliding friction power consumption is low, and the performance of the compressor using the sliding bearing system can be greatly improved. BRIEF DESCRIPTION OF DRAWINGS

[0020] The accompanying drawings, which form a part of this application, are included to provide a further understanding of the application and are incorporated in and constitute a part of this application. The embodiments of the present application and its description are used to explain the present application and are not used to limit the present application. In the drawings:

[0021] Figure 1 A sliding bearing system according to an embodiment of the present application is shown in the schematic diagram;

[0022] Figure 2 A friction coefficient comparison diagram according to an embodiment of the present application and a comparative example 1 is shown in the schematic diagram;

[0023] Figure 3 A wear depth comparison diagram after wear according to an embodiment of the present application and a comparative example 1 is shown in the schematic diagram;

[0024] Figure 4 A power consumption performance comparison diagram according to an embodiment of the present application and a comparative example 3 is shown in the schematic diagram;

[0025] Figure 5 An exploded view of a piston compressor cylinder base, a crankshaft and a sliding bearing according to an embodiment of the present application is shown in the schematic diagram;

[0026] Figure 6 An exploded view of a rotary compressor pump body and a sliding bearing according to an embodiment of the present application is shown in the schematic diagram; and

[0027] Figure 7An exploded view of a scroll compressor pump body and sliding bearing according to an embodiment of the present application is shown.

[0028] Wherein, the above figures include the following reference signs:

[0029] 10, cylinder block; 10a, shaft sleeve; 11, sliding bearing; 12, crankshaft; 20, cylinder; 21, roller; 22, sliding vane; 23, crankshaft; 24, upper flange; 25, upper sliding bearing; 26, lower flange; 27, lower sliding bearing; 30, crankshaft; 31, eccentric balance weight; 32, upper support; 33, upper sliding bearing; 34, lower support; 35, lower sliding bearing. DETAILED DESCRIPTION

[0030] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0031] The terms used in the embodiments of the present application are merely for the purpose of describing specific embodiments and are not intended to limit the present application. The singular forms "a", "said" and "the" used in the embodiments of the present application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise. "Plural" generally includes at least two, but does not exclude the case of including at least one.

[0032] It should be understood that the term "and / or" used herein is merely a description of the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the three cases of A alone, A and B together, and B alone. In addition, the character " / " herein generally represents an "or" relationship between the front and rear associated objects.

[0033] It should also be noted that the terms "include", "contain" or any other variants thereof are intended to cover non-exclusive inclusion, so that the goods or systems including a series of elements not only include those elements, but also include other elements not explicitly listed, or include elements inherent to such goods or systems. Without more limitations, the element defined by the statement "including a" does not exclude the presence of other identical elements in the goods or systems including the element.

[0034] As described in the background of the present application, the prior art has the problem that the compressor bearing part cannot simultaneously consider wear resistance and lubrication performance, and the sliding friction power consumption is large. In order to solve the above problem, in a typical embodiment of the present application, a sliding bearing system is provided, as shown in Figure 1As shown, the sliding bearing and the crankshaft are in mutual abrasion, and the low-viscosity lubricating oil is filled between the sliding bearing and the crankshaft, the material of the sliding bearing is high-silicon aluminum alloy, the weight percentage of silicon is 10.1-25.5 wt.%, the material of the crankshaft is nodular cast iron, and the low-viscosity lubricating oil comprises adsorption additives, the adsorption additives comprise one or more of hydroxyl polymers, phosphate ester polymers, amine phosphate polymers, phenol and phosphazene polymers.

[0035] The inventors unexpectedly found in the research process that the compressor crankshaft and bearing part are prone to adhesive wear, the existing low-viscosity lubricating oil has poor lubricating effect and unstable oil film, resulting in poor wear resistance and lubricating performance, and large sliding friction power consumption.

[0036] The inventors unexpectedly found in the research process that when the compressor adopts the low-viscosity lubricating oil as the lubricating medium, the wear between the parts in the compressor can be avoided to a great extent, the parts in the compressor can maintain a good lubricating state, and the low-viscosity lubricating oil can cool and take away part of the heat generated by the pump body and the motor during operation (the heat generated by the pump body and the parts during operation due to friction will heat the pump body and the parts, and the pump body and the parts will also generate heat during operation). Meanwhile, the low-viscosity lubricating oil filled between the sliding bearing and the crankshaft avoids the direct contact between the sliding bearing and the crankshaft, thereby achieving the purpose of weakening the friction resistance generated when the two parts move and reducing the friction coefficient.

[0037] However, as the viscosity of the lubricating medium decreases, it is difficult to form a stable oil film between the two matching parts of the existing gray cast iron part and the nodular cast iron crankshaft, and the gray cast iron part and the nodular cast iron crankshaft have the risk of direct contact and wear. Although the gray cast iron and the nodular cast iron have face-centered cubic and body-centered cubic lattice structures, the proportion of the face-centered cubic structure lattice with isotropy and easy crystal plane slip is not large, and the main part is the body-centered cubic crystal with stable structure which is not easy to slip. Moreover, the graphite in the nodular cast iron and gray cast iron matrix has little lubricating effect. Moreover, the two matching parts belong to cast iron materials, and the adhesive wear of the same material is prone to occur. Therefore, the sliding bearing of a specific material is added between the two matching parts, thereby avoiding the problem of adhesive wear of the same material.

[0038] In the sliding bearing system of the present application, the sliding bearing is made of high-silicon aluminum alloy, the weight percentage of silicon is 10.1-25.5 wt.%, and the matrix mainly has soft phase alpha-Al and dispersed hard phase eutectic silicon. The lattice of the soft phase alpha-Al is a face-centered cubic structure, and the crystal of this structure has isotropy and is easy to slip. The lattice of the nodular cast iron of the counter-abrasion crankshaft has a face-centered cubic structure and a body-centered cubic structure, and the body-centered cubic structure is not easy to slip and has a stable structure.

[0039] When the high-silicon aluminum alloy sliding bearing is coupled with the relatively hard nodular cast iron crankshaft, the soft phase alpha-Al is more likely to have crystal plane slip, thereby producing lubrication behavior similar to high-viscosity fluid, having self-repairing property under low-speed friction, and having very effective lubrication for the friction pair operating at low speed. Moreover, the shear strength of the soft phase is low, and the soft phase will form a transfer film on the surface of the nodular cast iron crankshaft during friction, so that the friction occurs between the soft phase lubricating film and the transfer film, thereby slowing down the wear and improving the lubrication performance. In addition, the high-silicon aluminum alloy matrix also has hard phase eutectic silicon phase, so that the hardness and strength of the soft aluminum matrix are improved as a whole, and therefore it has certain pressure resistance and can support the nodular cast iron crankshaft coupled therewith. The hard phase eutectic silicon phase also makes the aluminum alloy sliding bearing have excellent long-term wear resistance.

[0040] It should be noted that the inventors unexpectedly found during research that the higher the Si content in the high-silicon aluminum alloy, the lower the friction coefficient and the better the wear resistance; however, the higher the Si content, the more difficult the part is to form, the more brittle the aluminum alloy is, and the worse the impact resistance is. If the crankshaft jumps during the operation of the compressor, the sliding bearing with too high Si content is easily cracked and fails. Therefore, the present application limits the weight percentage of silicon in the high-silicon aluminum alloy to 10.1-25.5 wt.%. It should be noted that the wear-reducing and wear-resistant performance of the high-silicon aluminum alloy is mainly related to the hard phase silicon, and therefore the present application only limits the Si content range, and other components of the high-silicon aluminum alloy can use conventional components in the art. These can be understood by those skilled in the art, and will not be described here.

[0041] At this time, the coupled parts in the compressor are basically in a fluid lubrication state. According to the Stribeck equation and curve of the lubrication form, when the operating speed and load pressure are constant, the lower the kinematic viscosity of the lubricating oil, the lower the movement resistance between the coupled parts, thereby reducing the friction coefficient between the coupled parts and the friction power consumption between the parts.

[0042] However, the inventors unexpectedly found during the research that it is still difficult to form a stable lubricating oil film between the high-silicon aluminum alloy sliding bearing and the nodular cast iron crankshaft, because the high-silicon aluminum alloy sliding bearing substrate has a certain amount of hard phase eutectic silicon particles, but it is mainly composed of soft phase α-Al, and the nodular cast iron crankshaft has more than 60% of wear-resistant hard phase pearlite in addition to ferrite and distributed spheroidal graphite of different sizes, and the hardness of the nodular cast iron is much higher than that of the high-silicon aluminum alloy, which is easy to cause damage to the high-silicon aluminum alloy sliding bearing, so the lubricating medium (i.e. the low-viscosity lubricating oil of the present application) needs to be able to form a stable oil film between the high-silicon aluminum alloy sliding bearing and the nodular cast iron crankshaft, so as to separate the high-silicon aluminum alloy sliding bearing from the nodular cast iron, and thereby weaken the frictional resistance generated between the high-silicon aluminum alloy sliding bearing and the nodular cast iron crankshaft during the movement of the mating parts, and reduce the friction coefficient.

[0043] As described above, there is no technical solution in the prior art for improving the lubricating performance of the improved surface lubricating oil for aluminum-based, i.e. the lubricating performance of the existing low-viscosity lubricating mineral oil or alkylbenzene oil or synthetic oil on the surface of the aluminum alloy has not reached the best state, so the present application also adds an adsorption additive which can react with the surface of the high-silicon aluminum alloy to generate a chemisorbed oil film to the low-viscosity lubricating oil, the adsorption additive includes one or more of hydroxyl polymers, phosphate ester polymers, amine phosphate polymers, phenol and phosphazene polymers, thereby reacting to generate an Al[R]3 salt chemisorbed oil film (wherein R is an acid radical ion) on the surface of the high-silicon aluminum alloy sliding bearing, the chemisorbed oil film can be adsorbed on the surface of the aluminum alloy sliding bearing by chemical bonds, and has stronger adsorption force and carrying capacity, and a lower friction coefficient than the physical adsorbed oil film formed by van der Waals force, thereby achieving the purpose of further reducing the friction power consumption between the aluminum alloy sliding bearing and the nodular cast iron crankshaft.

[0044] It should be noted that the specific type of low-viscosity lubricating oil can be used in the conventional type in the art, and conventional pour point depressants, defoamers, tackifiers, surfactants, rust inhibitors, antioxidants, extreme pressure agents and other additives can be added as needed, which can be understood by those skilled in the art and will not be described here.

[0045] At the same time, the soft phase α-Al of the high-silicon aluminum alloy sliding bearing substrate has similar lubricating behavior to high-viscosity fluid, and the graphite in the nodular cast iron crankshaft also has a certain lubricating effect, and the low-viscosity lubricating oil containing the specific adsorption additive can form a mixed lubrication on the basis of the lubricating properties of the lubricating oil itself, combined with the stable chemisorbed oil film on the surface of the aluminum alloy, which can effectively reduce the sliding friction power consumption between the crankshaft and the sliding bearing, and also weaken the running noise of the compressor as a whole, and improve the refrigeration, heating performance and noise performance of the compressor as a whole.

[0046] In conclusion, the sliding bearing system of the present application can have good wear resistance and lubrication performance, low sliding friction power consumption, and thus can greatly improve the performance of the compressor using the same,

[0047] In order to make the high-silicon aluminum alloy have good friction coefficient, wear resistance, good forming performance and impact resistance, in a preferred embodiment, the high-silicon aluminum alloy has a silicon content of 17-19 wt.%; and / or the hardness H Al 105-240 HBW; and / or the yield strength of the high-silicon aluminum alloy is ≥300 MPa, such as 300-380 MPa, so as to better support the nodular cast iron crankshaft, and further improve the wear resistance of the aluminum alloy sliding bearing.

[0048] In a preferred embodiment, the nodular cast iron has a hardness H Fe 160-360 HBW, so as to better adapt to the hardness and strength of the high-silicon aluminum alloy of the present application.

[0049] In order to more fully generate a chemisorbed oil film and reduce the friction coefficient without affecting the performance of the low-viscosity lubricating oil itself, in a preferred embodiment, the low-viscosity lubricating oil has an adsorption additive content of 0.5-6.0 wt.%, so as to further reduce the friction power consumption between the aluminum alloy sliding bearing and the nodular cast iron crankshaft.

[0050] In a preferred embodiment, the adsorption additive includes one or more of a hydroxyl polymer, a phosphate polymer and a phosphorus amine polymer. The hydroxyl polymer includes one or more of a fatty glycol, a cyclic glycol and a phenyl-substituted fatty glycol; the phosphate polymer includes one or more of a trimethylphenyl phosphate, a triethyl phosphate, a butylene glycol phosphite, an alkyl phosphate, an alkyl phosphite and an aryl phosphate; and the phosphorus amine polymer includes one or more of a phosphorus amine, a phosphorus amide, a dialkyldithiophosphate amine and a dialkyldithiophosphate amine. The above adsorption additive reacts more fully and rapidly with the surface of the high-silicon aluminum alloy, which is conducive to further reducing the friction power consumption. Taking butylene glycol phosphite (RO)2POH as an example, the above chemical reaction process is as follows: when the adsorption additive is butylene glycol phosphite (RO)2POH, the micro-chemical reaction with the surface of the high-silicon aluminum alloy sliding bearing is Al+(RO)2POH→Al[OP(RO)2]3+H2↑, which is combined with the surface of the high-silicon aluminum alloy sliding bearing by chemical bonds, so as to form a stable adsorbed oil film on the surface of the aluminum alloy sliding bearing, and the adsorption capacity and load capacity are greatly improved.

[0051] For the purpose of further matching the kinematic viscosity of the low viscosity lubricating oil with the high-silicon aluminum alloy sliding bearing and the nodular cast iron crankshaft of the present application, in a preferred embodiment, the kinematic viscosity of the low viscosity lubricating oil at 40℃ is 4.0-10.0 mm 2 / s; preferably, a mixed medium of the low viscosity lubricating oil mixed with the refrigerant is filled between the sliding bearing and the crankshaft, the kinematic viscosity of the mixed medium is further reduced, and the kinematic viscosity of the mixed medium is 1.0-7.0 mm 2 / s, the anti-friction lubrication effect is better, and the practicability is stronger.

[0052] As described above, the present application uses high-silicon aluminum alloy as the base material of the sliding bearing. Since the silicon content in the high-silicon aluminum alloy is high, the linear expansion coefficient is generally above 16x10 -6 / ℃, which is much larger than that of the conventional gray cast iron (generally 10-14x10 -6 / ℃). In order to further reduce the risk of the high-silicon aluminum alloy sliding bearing and the nodular cast iron crankshaft being stuck under the working condition of the compressor being operated at high frequency, the present application further limits that the fitting clearance N between the high-silicon aluminum alloy sliding bearing and the nodular cast iron crankshaft, the wall thickness t of the sliding bearing, and the diameter D of the crankshaft satisfy formula (1):

[0053] (2tα1+α2D)ΔT<N≤(2tα1+α2D)ΔT+n (1),

[0054] In the formula, α1 is the linear expansion coefficient of the sliding bearing, α2 is the linear expansion coefficient of the crankshaft, t is the wall thickness of the sliding bearing, D is the diameter of the crankshaft, ΔT is the absolute value of the difference between the normal temperature and the working temperature of the sliding bearing, and n is the reserved clearance between the sliding bearing and the crankshaft. The normal temperature is 20-30℃, and the specific value can be adjusted according to the actual operation condition.

[0055] In a preferred embodiment, n is 0.0002-0.0050 mm, which can make the sliding bearing system of the present application applicable to most compressors, and the universality is stronger.

[0056] In another typical embodiment of the present application, a compressor is also provided, which comprises the sliding bearing system of the present application described above, and the overall refrigeration, heating performance and noise performance are improved, and the power consumption is reduced.

[0057] In a preferred embodiment, the compressor is a piston compressor, a rotor compressor, a vane compressor, a scroll compressor, a screw compressor, a positive displacement compressor, or a centrifugal compressor.

[0058] In an embodiment, as Figure 5As shown, the sliding bearing system of the present application is installed on a piston compressor for verification, the high-silicon aluminum alloy material sliding bearing 11 is interference-pressed into the shaft sleeve 10a of the cylinder seat 10, is soaked in low-viscosity lubricating oil added with butyl glycol phosphite, the crankshaft 12 of spheroidal graphite cast iron material is rotated at high speed in the high-silicon aluminum alloy material sliding bearing 11 during operation, the piston compressor assembled with the high-silicon aluminum alloy sliding bearing has lower power consumption than the conventional piston compressor not assembled with the high-silicon aluminum alloy sliding bearing at each frequency, and thus the performance of the compressor at each frequency band is improved.

[0059] In an embodiment, as shown, Figure 6 As shown, the sliding bearing system of the present application is installed on a rolling rotor compressor for verification, the pump body assembly of the rolling rotor compressor is composed of a cylinder 20, a roller 21, a sliding vane 22, a crankshaft 23 of spheroidal graphite cast iron material, an upper flange (upper bearing) 24, and a lower flange (lower bearing) 26, in order to reduce the friction power consumption between the crankshaft 23 of spheroidal graphite cast iron material and the upper flange 24 and between the crankshaft 23 of spheroidal graphite cast iron material and the lower flange 26, a high-silicon aluminum alloy material upper sliding bearing 25 is interference-pressed into the shaft hole of the upper flange 24, and a high-silicon aluminum alloy material lower sliding bearing 27 is interference-pressed into the shaft hole of the lower flange 26, and is soaked in low-viscosity lubricating oil added with butyl glycol phosphite, thereby reducing the operating power consumption of the compressor and improving the performance of the compressor.

[0060] In an embodiment, as shown, Figure 7 As shown, the sliding bearing system of the present application is installed on a rolling rotor compressor for verification, the pump body assembly of the rolling rotor compressor is composed of a cylinder 20, a roller 21, a sliding vane 22, a crankshaft 23 of spheroidal graphite cast iron material, an upper flange (upper bearing) 24, and a lower flange (lower bearing) 26, in order to reduce the friction power consumption between the crankshaft 23 of spheroidal graphite cast iron material and the upper flange 24 and between the crankshaft 23 of spheroidal graphite cast iron material and the lower flange 26, a high-silicon aluminum alloy material upper sliding bearing 25 is interference-pressed into the shaft hole of the upper flange 24, and a high-silicon aluminum alloy material lower sliding bearing 27 is interference-pressed into the shaft hole of the lower flange 26, and is soaked in low-viscosity lubricating oil added with butyl glycol phosphite, thereby reducing the operating power consumption of the compressor and improving the performance of the compressor.

[0061] Typically but not limitedly, the weight percentage of silicon in the high-silicon aluminum alloy is 10.1 wt.%, 11 wt.%, 12 wt.%, 13 wt.%, 14 wt.%, 15 wt.%, 16 wt.%, 17 wt.%, 18 wt.%, 19 wt.%, 20 wt.%, 21 wt.%, 22 wt.%, 23 wt.%, 24 wt.%, 25 wt.%, 25.5 wt.%, or any range value composed of any two of the above values.

[0062] Typically but not limitatively, the high-silicon aluminum alloy has a hardness H Al of 105 HBW, 110 HBW, 120 HBW, 130 HBW, 140 HBW, 150 HBW, 160 HBW, 170 HBW, 175 HBW, 180 HBW, 190 HBW, 195 HBW, 200 HBW, 210 HBW, 220 HBW, 230 HBW, 240 HBW, or any range of values between any two of these values.

[0063] Typically but not limitatively, the nodular cast iron has a hardness H Fe of 160 HBW, 170 HBW, 180 HBW, 190 HBW, 200 HBW, 210 HBW, 220 HBW, 230 HBW, 240 HBW, 250 HBW, 260 HBW, 270 HBW, 280 HBW, 290 HBW, 300 HBW, 310 HBW, 320 HBW, 330 HBW, 340 HBW, 350 HBW, 360 HBW, or any range of values between any two of these values.

[0064] Typically but not limitatively, the low-viscosity lubricating oil has a weight percentage of adsorbed additives of 0.5 wt.%, 1.0 wt.%, 1.5 wt.%, 2.0 wt.%, 2.5 wt.%, 3.0 wt.%, 3.5 wt.%, 4.0 wt.%, 4.5 wt.%, 5.0 wt.%, 5.5 wt.%, 6.0 wt.%, or any range of values between any two of these values.

[0065] Typically but not limitatively, the low-viscosity lubricating oil has a kinematic viscosity at 40 °C of 4.0 mm 2 / s, 4.5 mm 2 / s, 5.0 mm 2 / s, 5.5 mm 2 / s, 6.0 mm 2 / s, 6.5 mm 2 / s, 7.0 mm 2 / s, 7.5 mm 2 / s, 8.0 mm 2 / s, 8.5 mm 2 / s, 9.0 mm 2 / s, 9.5 mm 2 / s, 10.0 mm 2 / s or any range of values between any two of the recited values; the kinematic viscosity of the mixed medium is 1.0 mm 2 / s, 2.0 mm 2 / s, 3.0 mm 2 / s, 4.0 mm 2 / s, 5.0 mm 2 / s, 6.0 mm 2 / s, 7.0 mm 2 / s or any range of values between any two of the recited values.

[0066] Typically but not limitedly, the pre-clearance n between the sliding bearing and the crankshaft is 0.0002 mm, 0.0005 mm, 0.0010 mm, 0.0015 mm, 0.0020 mm, 0.0025 mm, 0.0030 mm, 0.0035 mm, 0.0040 mm, 0.0045 mm, 0.0050 mm or any range of values between any two of the recited values.

[0067] The application will be further described in conjunction with specific embodiments which should not be construed as limiting the scope of the application.

[0068] Example 1

[0069] A sliding bearing system for a piston compressor is provided, and a schematic diagram of the sliding bearing system is shown in Figure 1 The compressor has a closed cavity with a mixed medium of low viscosity lubricating oil and refrigerant R600a, and the sliding bearing is arranged between the parts in the compressor and the crankshaft. Among them:

[0070] The material of the sliding bearing is high-silicon aluminum alloy (the composition contains Si 18wt.%, Fe 6.0wt.%, Cu 4.0wt.%, Mg 1.0wt.%, and the balance is Al), the hardness H Al is 175 HBW, and the yield strength is 365 MPa; the material of the crankshaft is nodular cast iron, and the hardness H Fe is 210 HBW.

[0071] The low viscosity lubricating oil (containing adsorption additive 2.5wt.%, stabilizer 2.0wt.%) contains butylene glycol phosphite as the adsorption additive; the kinematic viscosity of the low viscosity lubricating oil at 40°C is 5.0 mm 2 / s, and the kinematic viscosity of the mixed medium after mixing the low viscosity lubricating oil with the refrigerant is 2.0 mm 2 / s.

[0072] The fit clearance N between the sliding bearing and the crankshaft should satisfy the relation (2tα1 + α2D)ΔT < N ≤ (2tα1 + α2D)ΔT + n, where α1 is 16.5 x 10 -6 / °C, α2 is 10.8 x 10 -6 / °C, t is 1.0 mm, D is 14.0 mm, ΔT is 75°C, and n is 0.00035 mm. The calculation gives 0.0138 mm < N ≤ 0.0142 mm.

[0073] Example 2

[0074] Example 2 differs from Example 1 in that the material of the sliding bearing is a high-silicon aluminum alloy (comprising, by weight percent, 10.1 wt.% silicon, and the other components are the same as in Example 1), having a hardness H Al of 105 HBW and a yield strength of 300 MPa. The material of the crankshaft is nodular cast iron, having a hardness H Fe of 160 HBW.

[0075] The fit clearance N between the sliding bearing and the crankshaft at this time satisfies the relation (2tα1 + α2D)ΔT < N ≤ (2tα1 + α2D)ΔT + n, where α1 is 20.2 x 10 -6 / °C, and the other components are the same as in Example 1. The calculation gives 0.0144 mm < N ≤ 0.0147 mm.

[0076] Example 3

[0077] Example 3 differs from Example 1 in that the material of the sliding bearing is a high-silicon aluminum alloy (comprising, by weight percent, 17 wt.% silicon, and the other components are the same as in Example 1), having a hardness H Al of 170 HBW and a yield strength of 350 MPa. The material of the crankshaft is nodular cast iron, having a hardness H Fe of 200 HBW.

[0078] The fit clearance N between the sliding bearing and the crankshaft at this time satisfies the relation (2tα1 + α2D)ΔT < N ≤ (2tα1 + α2D)ΔT + n, where α1 is 17.5 x 10 -6 / °C, and the other components are the same as in Example 1. The calculation gives 0.0140 mm < N ≤ 0.0143 mm.

[0079] Example 4

[0080] Example 4 differs from Example 1 in that the material of the sliding bearing is a high-silicon aluminum alloy (composition in weight percent, containing silicon 19 wt.%, other components same as Example 1), hardness H Al is 195 HBW, yield strength is 360 MPa. The material of the crankshaft is nodular cast iron, hardness H Fe is 230 HBW.

[0081] At this time, the fit clearance N between the sliding bearing and the crankshaft satisfies the relationship (2tα1+α2D)ΔT -6 / °C, other components same as Example 1. Calculation gives 0.0138 mm < N < 0.0141 mm.

[0082] Example 5

[0083] Example 5 differs from Example 1 in that the material of the sliding bearing is a high-silicon aluminum alloy (composition in weight percent, containing silicon 25.5 wt.%, other components same as Example 1), hardness H Al is 240 HBW, yield strength is 380 MPa. The material of the crankshaft is nodular cast iron, hardness H Fe is 360 HBW.

[0084] At this time, the fit clearance N between the sliding bearing and the crankshaft satisfies the relationship (2tα1+α2D)ΔT -6 / °C, other components same as Example 1. Calculation gives 0.0137 mm < N < 0.0140 mm.

[0085] Example 6

[0086] Example 6 differs from Example 1 in that the low-viscosity lubricating oil (composition in weight percent, containing adsorption additive 0.5 wt.%, other components same as Example 1), the adsorption additive is a cyclic diol; the kinematic viscosity of the low-viscosity lubricating oil at 40°C is 4.0 mm 2 / s, the kinematic viscosity of the mixed medium after mixing the low-viscosity lubricating oil with the refrigerant is 1.0 mm 2 / s, the refrigerant is R600a.

[0087] Example 7

[0088] The difference between Example 7 and Example 1 is that the low-viscosity lubricating oil (composition by weight percentage includes 6.0 wt.% adsorbent additive, other components are the same as in Example 1) uses ammonium phosphate as the adsorbent additive; the kinematic viscosity of the low-viscosity lubricating oil at 40°C is 10.0 mm. 2 / s, the kinematic viscosity of the mixture of low-viscosity lubricating oil and refrigerant is 7.0 mm. 2 / s, refrigerant is R600a.

[0089] Comparative Example 1

[0090] The difference between Comparative Example 1 and Example 1 is that the compressor bearing section does not use a high-silicon aluminum alloy sliding bearing, and the gray cast iron parts of the bearing section are directly rubbed against the ductile iron crankshaft.

[0091] Comparative Example 2

[0092] The difference between Comparative Example 2 and Example 1 is that no adsorption additives were added to the lubricating oil.

[0093] Comparative Example 3

[0094] The difference between Comparative Example 3 and Example 1 is that the compressor bearing section did not use a high-silicon aluminum alloy sliding bearing, the gray cast iron parts of the bearing section directly rubbed against the ductile iron crankshaft, and no adsorption additives were added to the lubricating oil.

[0095] The performance of the above embodiments and comparative examples was tested, and the results are shown in Table 1.

[0096] Test method:

[0097] Friction coefficient and wear resistance: The coefficient of friction and wear resistance were determined using a pin-disc universal friction and wear testing machine. Appropriate lubricating oils were used as the lubricating medium, and the specimens were immersed in the oil bath to achieve fluid lubrication. The rotational speed was set to 1200 r / min, the load (pressure) to 300 N, and the test time to 60 min. The material of the specimens on the pin disc was ductile iron. Based on a long-term gas pressure of 3.8 MPa for the pump components inside the compressor, the contact area between the friction specimens was calculated to be 124.8 mm². 2 The friction coefficient comparison chart between Example 1 and Comparative Example 1 is shown below. Figure 2 As shown, Figure 2 In this context, 2a represents the coefficient of friction in Comparative Example 1. Figure 2 In this figure, 2b represents the friction coefficient of Example 1. A comparison of the wear depth after wear in Example 1 and Comparative Example 1 is shown in the figure below. Figure 3 As shown, Figure 3 In the figure, 3a represents the wear depth of Comparative Example 1. Figure 3 In this context, 3b represents the wear depth of Example 1.

[0098] Power consumption: GB / T 5773. A comparison of power consumption performance between Example 1 and Comparative Example 3 is shown in the figure below. Figure 4 As shown, Figure 4 In the figure, 4a represents the power consumption performance of Comparative Example 3. Figure 4 4b in the table represents the power consumption performance of Example 1. The refrigerator typically operates at a frequency of 33Hz during normal operation; therefore, Table 1 further lists the performance at 33Hz for comparison.

[0099] Table 1

[0100]

[0101] Depend on Figure 2 It can be seen that, under the same test conditions, the high-silicon aluminum alloy sliding bearing used in Example 1 of the present invention can improve the friction performance when rubbing against the ductile iron crankshaft, and at the same time can react with the adsorption additive to form a stable chemical adsorption oil film, which keeps its friction coefficient at the lowest level. Compared with the gray cast iron material of Comparative Example 1, the friction power consumption is also lower. This is because: 1) The kinematic viscosity of the lubricating oil is low, and the kinematic viscosity is further reduced after mixing with the refrigerant. According to the Stribek curve, the kinematic resistance generated between the paired friction specimens is reduced, thereby reducing the friction coefficient between the paired specimens; 2) When the paired friction specimens are in a state of instantaneous boundary lubrication, the soft phase α-Al with a face-centered cubic lattice structure in the high-silicon aluminum alloy undergoes crystal plane slip, thereby playing a lubricating effect similar to grease, thus reducing the friction coefficient between the paired specimens; 3) The adsorption additives added to the low-viscosity lubricating oil that can chemically react with the aluminum alloy surface react with the surface of the high-silicon aluminum alloy sliding bearing to generate an Al[R]3 salt chemical adsorption oil film. This chemical adsorption oil film can be adsorbed on the surface of the aluminum alloy sliding bearing by chemical bonds, and its adsorption force and bearing capacity are stronger. The friction coefficient is much lower than that of the physical adsorption oil film formed by van der Waals forces alone, further reducing the friction coefficient between the paired specimens; 4) Graphite in ductile iron can also have a slight effect on reducing the friction coefficient between the paired specimens. That is, the sliding bearing system of Example 1 achieves the optimal lubrication state of four-fold composite lubrication: low motion resistance, soft metal crystal surface sliding, chemically adsorbed oil film, and graphite.

[0102] Depend on Figure 3It can be known that under the same test conditions, the high-silicon aluminum alloy of Example 1 has a better composite lubrication effect than the conventional gray cast iron of Comparative Example 1, and the silicon in the high-silicon aluminum alloy improves the hardness and strength of the aluminum alloy as a whole, thereby improving the compression resistance and wear resistance of the high-silicon aluminum alloy. Under the influence of the excellent composite lubrication effect and the high strength and high wear resistance of the aluminum alloy, the wear depth of the high-silicon aluminum alloy is lower than that of the conventional gray cast iron. The average wear depth of the high-silicon aluminum alloy is about 0.2079 μm, and the average wear depth of the conventional gray cast iron is about 2.3885 μm. That is, the average wear depth of the high-silicon aluminum alloy is 91.3% lower than that of the conventional gray cast iron. This is because the friction coefficient of the gray cast iron against the nodular cast iron is large, and the friction power consumption is high, thereby causing the wear depth of the gray cast iron to be the deepest. The aluminum alloy can react with the adsorbed additive to form a stable chemical adsorption oil film, so that a stable oil film can be formed between the nodular cast iron and the high-silicon aluminum alloy, and the probability of direct contact friction between the two friction pairs is smaller, so the wear scar is shallower.

[0103] By Figure 4 It can be known that the power consumption of the piston compressor equipped with the high-silicon aluminum alloy sliding bearing of Example 1 is lower than that of Comparative Example 3 which is not equipped with the high-silicon aluminum alloy sliding bearing and does not use the adsorbed additive, thereby improving the performance of the compressor in each frequency band. The reduction in power consumption of the compressor is the largest in the low frequency band (below 33 Hz) and the high frequency band (above 50 Hz), and the performance improvement is also the most obvious. At present, the means for reducing the power consumption of the piston compressor (optimizing the lubricating oil path structure, reducing the suction power consumption, improving the motor efficiency, etc.) has reached the limit, and the sliding bearing system of the present application can further reduce the power consumption of the compressor.

[0104] From the above, compared with the comparative examples, each embodiment of the present application uses high-silicon aluminum alloy as the material of the sliding bearing and uses nodular cast iron as the material of the crankshaft, the materials of the sliding bearing and the crankshaft are inconsistent, the risk of adhesive wear of the same material can be reduced, and the hard silicon phase in the high-silicon aluminum alloy matrix can improve the long-term wear resistance of the sliding bearing; secondly, a specific kind of adsorption additive is added to the low-viscosity lubricating oil, which can chemically react with the surface of the high-silicon aluminum alloy to form a chemisorbed oil film, the chemisorbed oil film can be adsorbed on the surface of the friction pair composed of the sliding bearing and the crankshaft by chemical bonds, the adsorption force and the carrying capacity are stronger, and the friction coefficient is also lower than that of the physical adsorbed oil film formed by van der Waals force, which can significantly improve the lubrication effect. Thirdly, the soft phase alpha-Al of the high-silicon aluminum alloy sliding bearing matrix has similar lubrication behavior as high-viscosity fluid, and the graphite in the nodular cast iron crankshaft also has a certain lubricating effect, and the low-viscosity lubricating oil containing the specific adsorption additive can form mixed lubrication based on the lubricating properties of the lubricating oil itself combined with the stable chemisorbed oil film on the surface of the aluminum alloy, and the three can effectively reduce the sliding friction power consumption between the crankshaft and the sliding bearing. In summary, the sliding bearing system of the present application can have good wear resistance and lubrication performance, low sliding friction power consumption, and thus the performance of the compressor using the same can be greatly improved.

[0105] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A sliding bearing system, characterized in that The sliding bearing and the crankshaft are filled with low viscosity lubricating oil, wherein, The sliding bearing is made of high-silicon aluminum alloy, wherein the weight percentage of silicon is 10.1-25.5 wt.%; The crankshaft is made of nodular cast iron; The low viscosity lubricating oil comprises adsorption additives, the adsorption additives comprise one or more of hydroxyl polymers, phosphate ester polymers, amine phosphate polymers and phosphazene polymers; the phosphate ester polymers comprise butylene glycol phosphite and / or alkyl phosphite; The fitting clearance N between the sliding bearing and the crankshaft satisfies formula (1): (2tα1+α2D)ΔT In the formula, α1 is the linear expansion coefficient of the sliding bearing, α2 is the linear expansion coefficient of the crankshaft, t is the wall thickness of the sliding bearing, D is the diameter of the crankshaft, ΔT is the absolute value of the difference between the normal temperature and the working temperature of the sliding bearing, and n is the reserved clearance between the sliding bearing and the crankshaft.

2. The sliding bearing system according to claim 1, wherein, The weight percentage of silicon in the high-silicon aluminum alloy is 17-19 wt.%; and / or the high-silicon aluminum alloy has a hardness H Al 105 to 240 HBW; and / or The yield strength of the high-silicon aluminum alloy is ≥300 MPa.

3. The sliding bearing system according to claim 1 or 2, wherein, The hardness H of the ductile iron Fe It is 160~360HBW.

4. The plain bearing system as claimed in claim 1 or 2, characterized in that In the low viscosity lubricating oil, The weight percentage of the adsorption additives is 0.5-6.0 wt.%.

5. The plain bearing system as claimed in claim 1 or 2, characterized in that In the adsorption additives, The hydroxyl polymers comprise one or more of aliphatic diols, cyclic diols and phenyl-substituted aliphatic diols; and / or The amine phosphate polymers comprise one or more of amine phosphates, phosphoramides, dialkyldithiophosphate amines and dialkyldithiophosphate amines.

6. The sliding bearing system according to claim 1 or 2, wherein, The low viscosity lubricating oil has a kinematic viscosity at 40°C of 4.0 to 10.0 mm 2 / s.

7. The sliding bearing system according to claim 6, wherein, The sliding bearing is filled with a mixed medium of low viscosity lubricating oil mixed with refrigerant between the sliding bearing and the crankshaft, the kinematic viscosity of the mixed medium being 1.0-7.0 mm 2 / s.

8. The plain bearing system as claimed in claim 1 or 2, characterized in that n is 0.0002-0.0050 mm.

9. A compressor comprising the sliding bearing system according to any one of claims 1-8.

10. The compressor of claim 9, wherein, The compressor is a positive displacement compressor or a centrifugal compressor. The compressor is a positive displacement compressor or a centrifugal compressor.

Images