JP2006207765A - Rolling bearing for compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rolling bearing having a longer life even when used in a position subjected under severe lubricating conditions of a compressor. <P>SOLUTION: On bearing rings 101a, 102a of a first race 101 and a second race 102 and the peripheral face (the rolling face) of a cylindrical roller 103, a lubricating coating of fluorinated synthetic oil is formed at a thickness of 0.1μm or more. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a rolling bearing for a compressor.

An example of a compressor for a car air conditioner is a variable capacity compressor. Patent Document 1 below describes an example of a variable displacement compressor.
As shown in FIG. 2, the compressor is of a swash plate type, and includes a drive shaft 2 disposed in the housing 1, a swash plate 3 with a variable inclination angle with respect to the drive shaft 2, and a swash plate 3. On the other hand, a disc-shaped wobble plate 4 slidably attached via a thrust bearing 5 is provided. The swash plate 3 rotates together with the drive shaft 2, and the wobble plate 4 moves as a “slashing motion” as the swash plate 3 rotates.

A cylinder block 11 is fixed to one end of the housing 1, and a pulley 8 is disposed at the other end. One end of the drive shaft 2 is rotatably supported by the cylinder block 11. The other end of the drive shaft 2 is rotatably supported by the pulley 8 via the clutch mechanism 18. A thrust plate 9 is press-fitted at a position closer to the pulley 8 than the wobble plate 4 of the drive shaft 2. A thrust needle bearing 10 is arranged between the thrust plate 9 and the housing 1.
One end of a plurality of piston rods 6 is attached to the peripheral portion of the wobble plate 4 at equal intervals in the circumferential direction. The other end of the piston rod 6 is connected to a piston 7 that slides in a cylinder bore 11 a formed in the cylinder block 11.

In addition, after the inside of the compressor is evacuated, refrigerant and lubricating oil are enclosed.
This compressor is driven by the rotation of the drive shaft 2 by the operation of the clutch mechanism 18. Along with this, the swash plate rotates, the wobble plate 4 performs a “slashing motion”, and the piston 7 reciprocates in the axial direction via the piston rod 6, thereby compressing the refrigerant flowing into the cylinder bore 11a. Discharged. At this time, the compressive force of the refrigerant is transmitted to the drive shaft 2 as a thrust force, and the thrust needle bearing 10 receives this thrust force between the thrust plate 9 and the housing 1.

In FIG. 2, the direction in which the refrigerant flows is indicated by arrows. Lubricating oil is in a state of being contained in a mist form in the refrigerant, and is carried by the refrigerant to lubricate each part. Since the thrust needle bearing 10 is located away from the piston 7, the lubrication conditions are severe and the oil film is easily broken.
In general, when used in the atmosphere, if the oil film formation on the rolling surface of the metal rolling bearing (the raceway surface of the bearing ring, the rolling surface of the rolling element) becomes insufficient, the oil film is broken. Even if metal contact occurs, a surface oxide film is formed by oxygen in the atmosphere, and further metal contact is prevented. However, in the case of this compressor, since the inside of the compressor is evacuated before the refrigerant is added, the internal oxygen concentration is low. Therefore, it is difficult to form a surface oxide film when the oil film is broken and metal contact occurs.
JP 2003-294039 A

  An object of the present invention is to provide a rolling bearing having a long life even when used in a position where the lubrication conditions of the compressor are severe.

The present invention relates to a rolling bearing that rotatably supports a drive shaft of a compressor with respect to a housing. A rolling bearing for a compressor is provided in which a lubricating coating made of a fluorine-based synthetic oil is formed with a thickness of 0.1 μm or more.
Examples of the fluorinated synthetic oil that can be used in the present invention include fluoropolyether, polyfluoroalkyl, and derivatives thereof (fluorine groups substituted with functional groups having high affinity for metals). Examples of the substituent include an epoxy group, an amino group, a carboxyl group, a hydroxyl group, a mercapto group, a sulfone group, and an ester group.

Since the fluorine-based synthetic oil has a low vapor pressure, it can exist on a metal rolling surface and raceway for a long period of time. In particular, the use of a fluorine-based synthetic oil having a chemical structure having a functional group with high affinity for metal causes a chemical bond between the functional group and the metal, so that the period in which the lubricating coating exists can be prolonged. it can.
In the rolling bearing of the present invention, it is preferable that the lubricating coating contains fluororesin particles (particle size: 0.1 to 5 μm). Examples of the fluororesin include polytetrafluoroethylene (PTPE), tetrafluoroethylene perfluorovinyl ether copolymer (PFA), and fluorinated ethylene propylene copolymer (FEP).

  As a method for forming a lubricating coating, for example, a method of immersing and pulling up a member for providing a lubricating coating in a solution in which fluorine synthetic oil is diluted with a solvent to a predetermined concentration and particles made of a fluororesin such as PTFE are added. Is mentioned. Moreover, the method of spraying and apply | coating the said solution to the surface which provides a lubricating film is also mentioned. Furthermore, after inject | pouring the predetermined amount of the said solution into a rolling bearing inside, the method of operating a rolling bearing and spreading over a raceway surface and a rolling surface is also mentioned.

Note that the thickness of the lubricating coating can be controlled by setting the concentration of the solution, the injection amount, and the like. Further, it is preferable to remove the volatile component by vacuum drying after forming the lubricating coating.
If the thickness of the lubricating coating is less than 0.1 μm, the lubricating effect by the lubricating coating cannot be obtained. On the other hand, when the thickness of the lubricating coating exceeds 10 μm, the torque is increased due to the resistance of the lubricating coating or dust generation is caused. A particularly preferable range of the thickness of the lubricating coating is 0.2 μm or more and 5 μm or less.

  According to the rolling bearing of the present invention, a lubricating coating made of a fluorine-based synthetic oil is formed with a thickness of 0.1 μm or more on at least one of the rolling surface of the rolling element and the raceway surface of the raceway. Even when the compressor is used in a severe position, the early wear is suppressed and the life is extended.

Hereinafter, embodiments of the present invention will be described.
The rolling bearing of this embodiment is shown in FIG. The rolling bearing 100 is a thrust needle bearing including a first race (orbital ring) 101, a second race (orbital ring) 102, a cylindrical roller (rolling element) 103, and a cage 104, and is shown in FIG. It can be used as a thrust needle bearing 10 for a compressor.
As this thrust needle bearing 100, one having dimensions of an inner diameter of 40 mm, an outer diameter of 60 mm, and a height of 5 mm was produced.

The first race 101, the second race 102, and the cylindrical roller 103 were produced by the following method. First, after processing the raw material consisting of SUJ2 into each shape, quenching (0.5 to 1.0 hour at 820 to 830 ° C.) and tempering (1 to 2 hour at 160 to 200 ° C.) were performed.
Next, as shown in Table 1, different treatments were performed on the cylindrical rollers 103 or both races 101 and 102 (processing objects) of each sample No. 1 to 30.
In Nos. 1 to 8, a lubricating coating having the configuration shown in Table 1 was formed on the cylindrical roller 103 without pretreatment. In Nos. 9 to 12, the lubricating coatings having the structure shown in Table 1 were formed on both races 101 and 102 without pretreatment.

  In Nos. 13 to 16, the cylindrical roller 103 or both races 101 and 102 were subjected to shot peening treatment as a pretreatment, and then a lubricating coating having the structure shown in Table 1 was formed. In Nos. 17 to 20, the cylindrical roller 103 or both races 101 and 102 were subjected to barrel treatment as a pretreatment, and then a lubricating coating having the configuration shown in Table 1 was formed. In Nos. 21 to 24, the cylindrical roller 103 or both races 101 and 102 were subjected to shot peening after barrel treatment as a pretreatment, and then a lubricating coating having the structure shown in Table 1 was formed.

In Nos. 25-26, the cylindrical roller 103 or both races 101, 102 were subjected to shot peening as pretreatment, but no lubricating coating was formed. In Nos. 27 to 28, the cylindrical roller 103 or both the races 101 and 102 were subjected to barrel treatment as a pretreatment, but no lubricating film was formed. In Nos. 29 to 30, the cylindrical roller 103 or both the races 101 and 102 were subjected to barrel treatment after the shot peening treatment as a pretreatment, but no lubricating film was formed.
The shot peening process was performed using SiC as a shot material by a method based on “JIS R 6001”.
The barrel treatment was performed with a rotary barrel using alumina particles as abrasive grains.

The lubricating coating was formed by the following method.
Fluorine-based synthetic oil for forming a lubricating coating includes (1) DuPont's "Crytox (registered trademark) FSH" and (2) Daikin Industries, Ltd.'s "Demnam (trade name) S-65. (3) “Fomblin (trade name) Z15” of Solvay Solexis Co., Ltd. (4) “Fomblin ZDIAC” of Solvay Solexis Co., Ltd. was prepared. In addition, “AK-225” from Asahi Clin Co., Ltd. was prepared as a solvent. In addition, “KD-500AS (trade name)” of Kitamura Co., Ltd. was prepared. This is a product in which PTFE (fluorine resin) particles are dispersed in a solvent, and the average particle size of PTFE particles is 0.3 μm, the average molecular weight is 3000, and the solvent is Vertrel XF (fluorocarbon type).

In No. 1, (1) “Crytox FSH” and (2) “Demnam S-65” were mixed at a mass ratio of (1) :( 2) = 1: 9, and the above-mentioned solvent was added to this and mixed. The oil concentration was 5% by mass. The diluted solution was kept at room temperature, and the cylindrical roller 103 was immersed therein for 10 minutes and then pulled up to form a lubricating film having a thickness of 0.8 μm.
In No. 2 to 4, (3) and "Fomblin Z15" (4) "Fomblin ZDIAC" in mass ratio (1): (2) = 9: 1 mixture, the solvent is added thereto Thus, the concentration of the mixed oil was set to 5% by mass. The diluted solution was kept at room temperature, and the cylindrical roller 103 was immersed in it for 10 minutes or more and then pulled up to form a lubricating film having a thickness of 0.8 μm, 0.1 μm, and 2.0 μm.

In No. 5, the solvent was added to (2) “DEMNUM S-65” to a concentration of 5 mass%. The diluted solution was kept at room temperature, and the cylindrical roller 103 was immersed in it for 5 minutes and then pulled up to form a lubricating film having a thickness of 0.8 μm.
In No. 6, (3) “fomblin Z15” was added with the solvent to a concentration of 5 mass%. The diluted solution was kept at room temperature, and the cylindrical roller 103 was immersed therein for 10 minutes and then pulled up to form a lubricating film having a thickness of 0.8 μm.

In No. 7, (2) The above solvent was added to “DEMNUM S-65” to a concentration of 5% by mass, and “KD-500AS” was added to change the content of PTFE particles to “DEMNUM S-65”. The amount was 10% by mass. This diluted solution containing particles was kept at room temperature, and the cylindrical roller 103 was immersed therein for 10 minutes and then pulled up to form a lubricating film having a thickness of 0.8 μm.
In No. 8, (3) The above-mentioned solvent was added to “fomblin Z15” to make the concentration 5 mass%, and the PTFE particles were made 10 mass% with respect to “fomblin Z15”. This diluted solution containing particles was kept at room temperature, and the cylindrical roller 103 was immersed therein for 10 minutes and then pulled up to form a lubricating film having a thickness of 0.8 μm.
In Nos. 13 to 24, after the pretreatment was performed by the above-described method, the lubricating film was formed by the same method as No. 1 or 2.

  And about No. 1-30, the cylindrical roller 103 or both races 101 and 102 which are the process object of each sample, and both races 101 and 102 which are not process objects (a pre-processing and formation of a lubricating film are not performed). In combination, the thrust needle bearing 100 was assembled using the same cage 104. For No. 31, the cylindrical needle roller 103 and the races 101, 102 that were not subjected to pretreatment or formation of a lubricating coating were combined, and the thrust needle bearing 100 was assembled using the same cage 104.

Wear tests were performed using these thrust needle bearings 100. The test conditions were an axial load (thrust force): 1500 N, a rotation speed: 4000 min ⁻¹ , an atmospheric gas: HCFC134a (including PAG), and a test time: 500 hours.
Before and after this test, the height H (see FIG. 1) of the thrust needle bearing 100 was measured. And the reduction | decrease amount of height (H) was computed. The results are also shown in Table 1.

As can be seen from Table 1, at least one of the raceway surface 101a of the first race 101, the raceway surface 102a of the second race 102, and the peripheral surface (rolling surface) of the cylindrical roller 103 has a thickness of 1 μm or more. In Nos. 1 to 24 in which the lubricating film was formed at 0.0 μm or less, the amount of decrease in height was as small as 0.9 μm or less. On the other hand, in No. 25-31 in which no lubricating film was formed on either, the amount of decrease in height was as large as 3.0-10.0 μm. In particular, Nos. 13 to 24 subjected to the pretreatment had a smaller amount of reduction in height than Nos. 1 to 12 not subjected to the pretreatment.
Furthermore, the comparison between No. 5 and No. 7, which differs only in the presence or absence of PTFE particles in the lubricating coating, comparison between No. 6 and No. 8, comparison between No. 9 and No. 11, and No. 10 From the comparison with No. 12, the amount of reduction in height was further reduced by containing PTFE particles in the lubricating coating.

From this result, a lubricating coating made of a fluorine-based synthetic oil is applied to at least one of the raceway surface 101a of the first race 101, the raceway surface 102a of the second race 102, and the peripheral surface (rolling surface) of the cylindrical roller 103. It can be seen that the thrust needle bearing 100 is formed with a thickness of 0.1 μm or more and 2.0 μm or less, so that early wear in the atmosphere of HCFC134a (containing PAG) is suppressed and the life is extended. Moreover, it turns out that a lifetime can be lengthened by containing PTFE particle | grains in the lubricating film which consists of a fluorine-type synthetic oil.
In this embodiment, a thrust needle bearing for a compressor for a car air conditioner is described. However, the rolling bearing of the present invention supports the drive shaft of the compressor so as to be rotatable with respect to the housing regardless of the type of the compressor. As long as it is a rolling bearing, it can be applied to any bearing.

For example, the deep groove ball bearing 16 shown in FIG. 5 can be used in place of the thrust bearing 15 that supports the cylinder block 11 side of the drive shaft 2 with the compressor of FIG. The deep groove ball bearing 16 includes an inner ring 161, an outer ring 162, balls (rolling elements) 163, and a cage 164. The inner ring 161, the outer ring 162, and the ball 163 are made of SUJ2. The retainer 164 is a corrugated retainer made of steel plate, but may be a crown retainer made of synthetic resin or the like.
A lubricating coating made of a fluorine-based synthetic oil is applied to at least one of the raceway surface 161a of the inner ring 161, the raceway surface 162a of the outer ring 162, and the surface (rolling surface) of the ball (rolling element) 163 of the deep groove ball bearing 16. Is formed with a thickness of 0.1 μm or more, early wear is suppressed and the life of the deep groove ball bearing 16 is extended.

It is sectional drawing which shows the thrust needle bearing equivalent to one Embodiment of this invention. It is sectional drawing which shows an example of a capacity | capacitance variable compressor. It is sectional drawing which shows the deep groove ball bearing corresponded to one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Housing 2 Drive shaft 3 Swash plate 4 Wobble plate 5 Thrust bearing 8 Pulley 9 Thrust plate 10 Thrust needle bearing 11 Cylinder block 11a Cylinder bore 15 Thrust bearing 16 Deep groove ball bearing (rolling bearing)
18 Clutch mechanism 100 Thrust needle bearing (rolling bearing)
101 First race (Raceway)
101a Raceway surface 102 Second race (Raceway)
102a raceway surface 103 cylindrical roller (rolling element)
104 Cage 161 Inner ring (Raceway)
162a Raceway 162 Outer ring (Raceway)
162a raceway surface 163 ball (rolling element)
164 Cage

Claims (2)

  In a rolling bearing that rotatably supports a drive shaft of a compressor with respect to a housing, the rolling element and the raceway are made of metal, and at least one of the rolling surface of the rolling element and the raceway surface of the raceway is made of a fluorine-based synthetic material. A rolling bearing for a compressor, wherein a lubricating film made of oil is formed with a thickness of 0.1 μm or more.   The rolling bearing for a compressor according to claim 1, wherein the lubricating coating is made of a fluorine-based synthetic oil containing fluorine resin particles.

Images