JPH04314868A - Sliding member - Google Patents

Abstract

PURPOSE:To obtian a sliding member excellent in wear resistance and sliding properties by forming an Ni-P plated layer with a prescribed thickness or above on the surface of an aluminum alloy or an aluminum composite having a low thermal expansion coefficient. CONSTITUTION:An Ni-P plated layer or an Ni-P/BN, Ni-P/SiC composite plated layer with about >=100mum thickness is formed on the surface of an aluminum alloy or aluminum composite material having a low thermal expansion coefficient. In this way, an alloy layer contg. ceramic particles having high hardness and solid lubricity or having high hardness is formed on the surface of a substrate. Thus, the wear resistance and sliding properties of the aluminum alloy or aluminum composite material can be improved.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the structure of sliding members such as vane (blade) members and rotor members for rotary compressors.

0002

[Prior Art] For example, a rotary compressor used in an air conditioner includes a rotary cylinder, a rotor that is eccentrically rotatably supported within the rotary cylinder, and a rotor that is slidable in a vane groove on the inner peripheral surface of the rotary cylinder. It consists of a vane that is fitted into the rotor and always slides on the rotor surface, a front head and a rear head on both sides of the cylinder, etc. When the drive motor rotates, the rotor rotates eccentrically within the cylinder due to the rotation of the cam on the camshaft, whereby refrigerant gas flows into the cylinder from the suction port, is compressed, and is discharged from the discharge port. Ru. At this time, the vanes perform reciprocating sliding (protrusion and retraction) motions at a considerable speed in the radial direction of the rotor in accordance with the eccentric rotation of the rotor. Incidentally, sliding members such as the rotor and vanes described above have conventionally been generally made of steel or cast iron from the viewpoint of wear resistance and coefficient of thermal expansion. Recently, inverter-based phase control has become mainstream in rotary compressors for air conditioners such as those described above, so high-speed rotation has become an unavoidable requirement.

However, the above-mentioned steel and cast iron naturally have a high specific gravity and a large mass. As a result, the load on the rotor bearing is large, and the swing of the crankshaft is also large. Therefore, problems such as contact between the rotor and stator in the motor section arise, and there is a drawback that high speed rotation above a certain level cannot be supported.

[0004] Also, regarding the vanes, when the vanes rotate at a high speed exceeding a predetermined value, the inertia force increases and the reciprocating motion cannot follow the rotation of the rotor, which impairs the sealing performance and causes gas leakage.

[0005] Under these circumstances, consideration has been given to manufacturing sliding members such as the rotor and vanes from lightweight and wear-resistant aluminum alloy.

However, in the case of a normal aluminum alloy alone, the coefficient of thermal expansion is approximately twice that of iron, so the fluctuation in clearance with other iron parts such as rotary cylinders becomes too large and the wear resistance deteriorates. There are problems such as low cost, and it cannot be put into practical use as it is.

[0007] Therefore, recently, improvements in wear resistance,
Aluminum composite materials containing various reinforcing materials have been devised to reduce the coefficient of thermal expansion.

For example, aluminum composite materials (Japanese Patent Application Laid-Open No. 63-230983) in which SiC whiskers, which are ceramic fibers, are impregnated with aluminum alloy under pressure, SiC,
Aluminum composite material in which ceramic particles such as BN are dispersed as a reinforcing material (Japanese Unexamined Patent Publication No. 62-30838)
etc.

[0009]

[Problem to be solved by the invention] However, the above-mentioned Japanese Patent Application Laid-Open No. 6
In the composite material made of SiC whiskers and aluminum alloy shown in Publication No. 3-230983, the coefficient of thermal expansion is sufficiently reduced due to the action of the SiC whiskers, but on the other hand, it has poor wear resistance and aggressiveness to the mating material. There are the following problems.

That is, SiC whiskers, which are ceramic fibers, have high heat resistance and hardness, and when composited with metals such as aluminum alloys, they have the characteristic of significantly improving heat resistance strength and hardness. The Mohs hardness is very high, with a hardness value of 9, so if the whiskers fall out of the aluminum alloy matrix during sliding, they act like an abrasive on the sliding surface and seriously damage the aluminum composite body and the mating material. It has the disadvantage of causing wear. In other words, there is a problem in that it is highly aggressive towards the opposing material.

On the other hand, as shown in the above-mentioned Japanese Patent Laid-Open No. 62-30838, Al2O3, Si3N4, SiC
Aluminum composite materials have also been invented in which ceramic particles such as BN and BN are mixed into an aluminum alloy as a reinforcing material. It has the disadvantage that it easily falls off the sliding surface compared to the case of , and there are still problems in terms of wear resistance and aggressiveness to the mating material.

0012

[Means for Solving the Problems] The inventions recited in claims 1 to 6 of the present application have been made for the purpose of solving the above problems, and are each constructed as follows. ing.

(1) Structure of the sliding member according to the invention set forth in claim 1 The sliding member according to the invention set forth in claim 1 has a Ni-P plating layer formed on the surface of an aluminum alloy having a low coefficient of thermal expansion with a predetermined thickness or more. It is configured as follows.

(2) Structure of the sliding member of the invention according to claim 2 The sliding member according to the invention according to claim 2 has a Ni-P/BN composite of a predetermined thickness or more on the surface of an aluminum alloy with a low coefficient of thermal expansion. It is constructed by forming a plating layer.

(3) Structure of the sliding member according to the invention according to claim 3 The sliding member according to the invention according to claim 3 has Ni-P/SiC composite plating of a predetermined thickness or more on the surface of an aluminum alloy with a low coefficient of thermal expansion. It is composed of layers.

(4) Structure of the sliding member according to the invention according to claim 4 The sliding member according to the invention according to claim 4 has a Ni-P plating layer of a predetermined thickness or more on the surface of an aluminum composite material with a low coefficient of thermal expansion. formed and composed.

(5) Structure of the sliding member according to the invention set forth in claim 5 The sliding member according to the invention set forth in claim 5 includes Ni-P/BN of a predetermined thickness or more on the surface of an aluminum composite material with a low coefficient of thermal expansion. It is constructed by forming a composite plating layer.

(6) Structure of the sliding member according to the invention set forth in claim 6 The sliding member according to the invention set forth in claim 6 includes Ni-P/SiC of a predetermined thickness or more on the surface of an aluminum composite material with a low coefficient of thermal expansion.
It is constructed by forming a composite plating layer.

[0019]

[Function] Since the sliding members of the inventions recited in claims 1 to 6 of the present application are constructed as described above, they exhibit the following functions corresponding to the respective constructions.

(1) Effect of the sliding member according to the invention claimed in claim 1 The sliding member according to the invention claimed in claim 1 has Ni--P of a predetermined thickness or more on the surface of the aluminum alloy having a low coefficient of thermal expansion as described above.
A sliding member is formed by forming a plating layer. Ni-P
When they are combined with each other to form an alloy, their hardness increases and they greatly contribute to improving wear resistance, and they also have a relatively low specific gravity and are light.

Therefore, if a sufficiently thick plating layer is formed on the surface of an aluminum alloy that contains Si or the like and has a low coefficient of thermal expansion by the Ni-P combination, the aluminum alloy material itself will eventually It is possible to obtain the advantages of light weight and low thermal expansion coefficient based on the characteristics of , and the advantage of improved wear resistance due to the Ni-P plating layer without increasing mass, and to create a good sliding member that can handle high-speed rotation. It can be realized.

Furthermore, the hardness of the Ni--P plating layer is not as high as that of, for example, SiC particles (Mohs hardness: 9), and the sliding property is good, so that the aggressiveness against the mating material is also low.

(2) Effect of the sliding member of the invention claimed in claim 2 The sliding member of the invention claimed in claim 2 comprises a Ni-P/BN composite having a predetermined thickness or more on the surface of an aluminum alloy having a low coefficient of thermal expansion. A sliding member is formed by forming a plating layer. As mentioned above, when Ni--P is alloyed with each other, its hardness increases, and therefore it greatly contributes to improving wear resistance.

[0024] BN (boron nitride) is a ceramic particle that has relatively high wear resistance and functions effectively as a reinforcing material, but it particularly has solid lubricating properties and has the effect of improving sliding properties. When the ceramic particles BN are simply mixed as a reinforcing material as in the past, they tend to fall off the sliding surface due to their shape (particle shape), but in the present invention, this can be prevented. It is made into a composite with Ni-P and is formed in the metal plating layer. Therefore, falling off from the sliding surface is less likely to occur, and moreover, the attack on the mating material is lower than in the case of only Ni--P. As a result, it can greatly contribute to reducing the relative amount of wear on the sliding parts.

Therefore, if a sufficiently thick plating layer is formed using Ni-P/BN on the surface of the aluminum alloy having a low coefficient of thermal expansion, the aluminum alloy material itself will have a low coefficient of thermal expansion. Moreover, it is possible to realize a good sliding member whose sliding surface has high wear resistance and sliding properties, and is highly compatible with high-speed rotation.

(3) Effect of the sliding member according to the invention set forth in claim 3 The sliding member according to the invention set forth in claim 3 has Ni--P of a predetermined thickness or more on the surface of the aluminum alloy having a low coefficient of thermal expansion as described above.
/SiC composite plating layer is formed to constitute the sliding member. As mentioned above, when Ni--P is combined with each other to form an alloy, the hardness increases, and therefore it greatly contributes to improving the wear resistance.

[0027] Furthermore, SiC is a ceramic particle, and due to its characteristics, it has particularly high wear resistance and functions extremely effectively as a reinforcing material for improving wear resistance. However, when ceramic particles SiC are simply mixed as a reinforcing material as in the past, they tend to fall off the sliding surface due to their shape (particle shape), and instead attack the mating material. However, in the present invention, Ni
-P is combined with P and is formed in the metal plating layer. Therefore, falling off from the sliding surface is less likely to occur, the attack on the mating material is also reduced, and the high abrasion resistance improvement effect can be effectively utilized. Moreover, the above Ni-P/SiC
If it is formed as a sufficiently thick plating layer on the surface of the aluminum alloy with a low coefficient of thermal expansion, the aluminum alloy material itself will have a low coefficient of thermal expansion, and the wear resistance of the sliding surface will be particularly high. , it is possible to realize a good sliding member that can handle high-speed rotation.

(4) Effect of the sliding member according to the invention set forth in claim 4 The sliding member according to the invention set forth in claim 4 has a predetermined thickness or more of Ni-
A sliding member is formed by forming a P plating layer. As mentioned above, when Ni--P is combined with each other to form an alloy, the hardness becomes high and it greatly contributes to improving the wear resistance, and the specific gravity is relatively small and light.

Therefore, by using the Ni-P and compositing it with ceramic fibers such as short alumina fibers, a sufficient thickness can be formed on the surface of the aluminum composite material, which inherently has high wear resistance and has a low coefficient of thermal expansion. If a metal plating layer is formed, the mass can be increased while combining the advantages of high wear resistance and low thermal expansion coefficient based on the characteristics of the material itself and the high wear resistance improvement due to the Ni-P plating layer. Therefore, it is possible to synergistically obtain a better sliding member.

Moreover, since the hardness of Ni--P is not as high as that of, for example, SiC particles (Mohs' hardness: 9), the aggressiveness toward the mating material is also low.

(5) Function of the sliding member according to the invention set forth in claim 5 The sliding member according to the invention set forth in claim 5 has Ni--
A sliding member is formed by forming a P/BN composite plating layer. As mentioned above, when Ni--P is combined with each other to form an alloy, the hardness increases, and therefore it greatly contributes to improving the wear resistance.

[0032] Furthermore, BN is a ceramic particle that has relatively high wear resistance and functions effectively as a reinforcing material. When the ceramic particles BN are simply mixed alone as a reinforcing material as in the past, they tend to fall off the sliding surface due to their shape (particle shape), but in the present invention, they are -P is combined with P and is formed in the metal plating layer. Therefore, falling off from the sliding surface as in the conventional case is less likely to occur, and the solid lubricity of BN also reduces the attack on the mating material. As a result, it can effectively contribute to reducing the relative amount of wear on the sliding parts.

Therefore, if a sufficiently thick plating layer is formed using the Ni-P/BN on the surface of the aluminum composite material, which is inherently high in wear resistance and has a low coefficient of thermal expansion, the material itself will eventually deteriorate. However, it is now possible to realize a high-speed sliding member that has high wear resistance and a low coefficient of thermal expansion, and in particular has high wear resistance and sliding properties on the sliding surface.

(6) Effect of the sliding member according to the invention set forth in claim 6 The sliding member according to the invention set forth in claim 6 has a predetermined thickness or more of Ni-
A sliding member is constructed by forming a P/SiC composite plating layer. As mentioned above, when Ni--P is combined with each other to form an alloy, the hardness increases and it greatly contributes to improving the wear resistance.

[0035] Furthermore, SiC is a ceramic particle that has particularly high wear resistance and functions effectively as a reinforcing material for improving wear resistance. However, when the ceramic particles SiC are simply mixed as a reinforcing material as in the past, they tend to fall off the sliding surface due to their shape (particle shape), and on the contrary, they are more likely to attack the mating material. However, in the present invention, this is combined with Ni-P and formed in the metal plating layer. Therefore, falling off from the sliding surface is less likely to occur, the attack on the mating material is also reduced, and only the wear resistance improving effect can be effectively utilized. Moreover, if the Ni-P/SiC is formed as a plating layer of sufficient thickness on the surface of the aluminum composite material, which has high wear resistance and a low coefficient of thermal expansion, the material itself will have a coefficient of thermal expansion. It is now possible to realize a sliding member that is suitable for high-speed rotation and has low wear resistance and especially high wear resistance on the sliding surface.

[0036]

[Effects of the Invention] As is clear from the above description, the sliding member of the invention described in each of claims 1 to 6 of the present application has low aggressiveness toward the mating material, is lightweight, and has a low coefficient of thermal expansion. In particular, it becomes possible to provide a sliding member suitable for high-speed rotation, such as for rotary compressors with high friction and wear characteristics.

Therefore, even if it were applied to the rotor member or vane member of a rotary compressor for an air conditioner controlled by an inverter, it would be possible to rotate at a sufficiently high speed and maintain a stable clearance. It is possible to reliably eliminate the drawbacks of conventional sliding members.

[0038]

[Embodiments] Hereinafter, embodiments of the present invention will be described in detail.

First, in this example, an Al-Si-Cu-Mg system having a composition as shown in Table 1 below, for example, 18.0
A sliding material was manufactured by applying Ni-P plating to a thickness of, for example, 100 μm on the surface of an aluminum alloy having a low coefficient of thermal expansion of about /106·°C.

[0040]

[Table 1]

The wear test is carried out using the pin-on-disc friction and wear tester shown in FIG. 1 in oil using the pin-shaped test pieces 3a to 3c shown in FIG. 1, which will be described later. As comparative materials, (D) JIS C9A aluminum alloy (same composition as in Table 1), (E) aluminum alloy/SiC whisker, which are generally used for rotary compressor vanes as shown in Table 2 below. I chose a single composite material. As the mating material, Ni-Cr-Mo cast iron (hardenable cast iron), which is commonly used as a roller material for the rotary compressor, was used.

[0042]

[Table 2]

Next, the pin-on-disk friction and wear tester shown in FIG. 1 will be briefly explained. In FIG. 1, reference numeral 1 indicates a first disk on the fixed side, numeral 2 indicates a second disk on the rotary drive side, and numerals 3a, 3b, and 3c (not shown because 3c is not visible) are fixed to the first disk 1 side. The above-mentioned three pin-shaped test pieces are shown respectively. Then, by sliding the pin-shaped test pieces 3a, 3b, 3c and the second disk 2, the amount of wear between the pin-shaped test pieces 3a, 3b, 3c and the second disk 2, which is the mating material, is measured. . For the wear test, as mentioned above, three types (A) to (C) shown in (Table 2) above were selected as samples of the invention material of the present application, and on the other hand, as comparative materials, the samples shown in (Table 2) above were selected. (D),
We selected two materials (E). Further, as described above, as the material of the counterpart (second disk), Ni-Cr-Mo cast iron, which is commonly used as a rotor material, was used. In addition, the wear test was carried out as wear test I at two sliding speeds of 1 m/sec and 2 m/sec.
Two surface pressures: 645kgf/cm2 and 485kgf/cm2
The wear volume of each pin-shaped test piece (3a, 3b, 3c in FIG. 1 above) and the second disk (2 in FIG. 1 above) was measured under various conditions, for example, after 7 hours of operation. Furthermore, as wear test II, a sliding speed of 1 m/sec and a surface pressure of 85
Operation 1 was set to even stricter conditions of 0 kgf/cm2.
The wear volume of the pin-shaped test pieces (3a, 3b, 3c in FIG. 1) after the time was measured.

Looking at the test results, for example, Fig. 2 (velocity 1 m/s, surface pressure 645 kgf/cm2, 70° C. in oil) and Fig. 3 (velocity 2 m/s, surface pressure 485 kgf/cm2,
In oil at 70°C), the N of the present invention
The aluminum alloy material (A) with i-P plating is (
D) and (E) exhibit high wear resistance superior to any of the comparative materials.

[0045] Also, (B) Ni-P/BN composite plating material and (C) Ni-P/BN composite plating material, which are also the materials of the present invention.
Regarding the SiC composite plating material, the sliding speed is 1 m/s,
A wear test was conducted under two conditions: a surface pressure of 645 kgf/cm2, a sliding speed of 2 m/s, and a surface pressure of 485 kgf/cm2. The results are also shown in FIGS. 2 and 3, and both (B) and (C) showed higher wear resistance than the comparative materials (D) and (E).

As is clear from the above test results, even in the case of aluminum alloy alone, which has relatively low wear resistance as a material, Ni-P, Ni-P/BN, Ni-P/S
If alloy plating such as iC is applied, the wear resistance can be sufficiently improved, and together with the reduction in the coefficient of thermal expansion, which is a characteristic of aluminum alloy, a good sliding member can be obtained. The thickness of the plating layer is preferably approximately 100 μm from the viewpoint of reliability.

Therefore, a low coefficient of thermal expansion (for example, 13. 1/106・℃, 12.2/
It is clear that the same effect of improving wear resistance can be obtained even if Ni--P alloy plating as described above is applied to an aluminum composite material having a temperature of 106° C.).

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a state of a wear test of a sliding member using a friction and wear tester according to an embodiment of the present invention.

FIG. 2 is a graph showing the test results of the wear test shown in FIG. 1 under predetermined test conditions.

FIG. 3 is a graph showing the test results of the wear test of FIG. 1 under test conditions different from those of FIG. 2;

Claims (6)

[Claims] 1. A sliding member formed by forming a Ni--P plating layer of a predetermined thickness or more on the surface of an aluminum alloy with a low coefficient of thermal expansion. 2. A sliding member formed by forming a Ni-P/BN composite plating layer of a predetermined thickness or more on the surface of an aluminum alloy with a low coefficient of thermal expansion. 3. A sliding member formed by forming a Ni-P/SiC composite plating layer of a predetermined thickness or more on the surface of an aluminum alloy with a low coefficient of thermal expansion. 4. A sliding member formed by forming a Ni--P plating layer of a predetermined thickness or more on the surface of an aluminum composite material with a low coefficient of thermal expansion. 5. A sliding member formed by forming a Ni-P/BN composite plating layer of a predetermined thickness or more on the surface of an aluminum composite material with a low coefficient of thermal expansion. 6. A sliding member formed by forming a Ni-P/SiC composite plating layer of a predetermined thickness or more on the surface of an aluminum composite material with a low coefficient of thermal expansion.