JP2001289169A - Compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compressor of high efficiency and reliability making reduction capable of a sliding loss without causing surface damage of abrasion or the like by direct contact in a journal bearing part of the compressor even by using an HFCs refrigerant or a natural refrigerant containing no chlorine with a poor abrasion resistance characteristic. SOLUTION: Crowning is formed in a journal bearing end part of a journal bearing part for a compressor, also an oil film thickness parameter value Λrepresenting a bearing characteristic of the journal bearing part is set to Λ>3.3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a journal bearing of a refrigerant compressor used for a refrigerator or an air conditioner.

[0002]

2. Description of the Related Art As electric compressors for refrigeration and air conditioning, there are reciprocating compressors, rotary compressors and scroll compressors, all of which are used in home and commercial refrigeration and air conditioning fields. In any type of compressor, the radial force of the main shaft that drives the compression section is supported by journal bearings. Here, a conventional technology will be described taking a scroll type compressor as an example. Japanese Patent Laid-Open No. 6-3073 discloses a scroll compressor used for air conditioning.
One disclosed in Japanese Patent Publication No. 56 is known.

FIG. 5 is a longitudinal sectional view of a conventional scroll compressor. A compression mechanism 2 in which a fixed scroll 2a and a movable scroll 2b orbiting with respect to the fixed scroll 2a are engaged, a thrust bearing 3 for supporting the movable scroll 2b, and a bearing for supporting the thrust bearing 3 are provided inside the closed casing 1. The component 4 is provided on the upper part. Then, the shaft 2c of the movable scroll 2b is inserted into the eccentric bearing 6 of the hole provided in the crank 5a at the end of the main shaft 5, and the movable scroll 2b
Is rotated by the rotational motion of the main shaft 5. A rotor 7 a of an electric motor 7 is attached to the main shaft 5, and a bearing component 4 together with a stator 7 b shrink-fitted and fixed to the closed casing 1.
It is arranged at the lower part. The journal bearing 8 is formed by press-fitting an annular bush material into the bearing component 4 and supports a radial force acting on the main shaft 5. An oil sump 10 for storing a lubricating oil 9 is provided at a lower bottom portion of the closed container 1. Further, a suction pipe 11 for a refrigerant gas is provided on a side portion of the closed container 1. The gas pressure on the suction side acts on the lower side of the spacer 22 inside the sealed container 1, and the gas pressure on the compression side acts on the upper side of the spacer 22. The bearing part 4 is provided with an oil outlet 12 for lubricating the journal bearing 8, the eccentric bearing 6, and the thrust bearing 3 and discharging the lubricating oil 9 cooled.
The main shaft 5 has a through hole 1 for supplying a lubricating oil 9 to each bearing portion, that is, a journal bearing 8, an eccentric bearing 6, and a thrust bearing 3.
An oil guide 14 is press-fitted or shrink-fitted and fixed to the lower end of the main shaft 5 so as to suck up the lubricating oil 9. Reference numeral 15 denotes a discharge chamber provided above the fixed scroll 2a, and reference numeral 16 denotes a discharge pipe for discharging compressed gas to the outside of the closed vessel 1. The fixed scroll 2a and the bearing component 4 are fastened by bolts with the spacer 22 interposed therebetween. The spacer 22 is hermetically welded and fixed to the airtight container 1 at its outer periphery, and serves as a partition between a lower suction pressure portion and an upper compression pressure portion. Reference numeral 19 denotes a check valve for preventing the movable scroll 2b from rotating backward when stopped, reference numeral 24 denotes a check valve guide for restricting the movement of the check valve, and reference numeral 20 denotes an orbital movement of the movable scroll 2b with respect to the fixed scroll 2a. Oldham ring for preventing rotation of the compression mechanism 21
This is a suction port provided in the bearing component 4 for sucking low pressure gas.

Next, the operation of the compression mechanism including the above mechanism will be described. The low-pressure gas returns from the suction pipe 11, and the compression mechanism 2
Inhaled. By rotating the movable scroll 2b so as not to rotate with respect to the fixed scroll 2a, a plurality of compression spaces formed between the fixed scroll 2a and the movable scroll 2b are gradually reduced from the outside to the inside. Compression is performed. The compressed gas becomes a high-pressure gas and once enters the discharge chamber 15. Then, the gas is discharged from the discharge pipe 16 to the outside of the closed vessel 1 and the low-pressure gas is circulated again, thereby forming a known compression cycle.

On the other hand, the lubricating oil 9 sucked up by the oil guide 14 rises in the through hole 13 of the main shaft 5, lubricates and cools the eccentric bearing 6, the thrust bearing 3, and the journal bearing 8, and the oil discharge port. A lubrication cycle is formed which is discharged from 12 to the upper part of the stator 7b and returns to the sump 10 through the notch 18 of the stator 7b.

In a conventional commercial scroll compressor, hydrochlorofluorocarbon (HCFC2) is used as a refrigerant.
In 2), mineral oil was used as a refrigerator oil. A gray cast iron material was used for the main shaft 5 and the bearing component 4, and a sliding portion was subjected to a surface hardening treatment such as induction hardening. The journal bearing 8 is formed by press-fitting an annular resin composite bearing material with a back metal or a metal bearing material with a back metal into the bearing component 4. The resin composite bearing material with a backing metal is a bearing material in which a steel plate having a thickness of about 1.3 to 1.8 mm is used as a backing metal and a porous sintered layer and a resin layer are formed on the upper surface of the steel plate. Similarly, a metal bearing material with a back metal is a bearing material in which a steel plate is used as a back metal and a bearing metal layer such as a copper alloy, an aluminum alloy, or a lead-based white metal is formed on the upper surface of the steel plate.

[0007] A radial load acts on the orbiting scroll for the radial component of gas pressure in the compression chamber, inertia force, and the like. This load rotates in the same direction as the rotation of the main shaft 5, and is supported by the journal bearing 8 via the eccentric bearing 6. That is, the main shaft 5 made of cast iron material
Is rotated by a very large load generated by gas compression or the like while being pressed against the inner surface of the journal bearing 8. By the rotation of the main shaft, a wedge-shaped oil film is formed inside the journal bearing, and the main shaft is supported by balancing the resultant force of the generated oil film pressure and the load.
Since the oil film is formed between the main shaft and the inner surface of the journal bearing, the state where the main shaft and the inner surface of the journal bearing are not in direct contact, that is, the lubricating state is a fluid lubricating state, and no large wear occurs.

In general, if the slip surface is completely smooth,
A fluid film having a film thickness in accordance with the theory of fluid lubrication is formed, and lubrication by a continuous fluid film is performed until the thickness becomes about the molecular layer.
However, in actuality, the surfaces with surface irregularities and undulations approach each other, so when the film thickness becomes about the same as the height of the surface irregularities, contact between the two surfaces at the tip of the projection starts, and that part is It becomes a state of boundary lubrication. The transition from fluid lubrication to mixed lubrication occurs even though the average film thickness is considerable.

Therefore, when the concept of the oil film thickness parameter Λ (the ratio of the oil film thickness h obtained as a smooth surface to the composite roughness σ) expressed by the following equation (1) is introduced,

[0010]

(Equation 1) In the region of Λ ≦ 1, boundary lubrication occurs completely, and in the region of Λ> 1, fluid lubrication can be expected from mixed lubrication.

In the fluid lubrication state, the oil film thickness parameter value Λ
The smaller the oil film thickness, the smaller the oil film thickness and the lower the coefficient of friction, which reduces the sliding loss in journal bearings. Reduction and higher efficiency. However, if the oil film thickness parameter value Λ is excessively reduced, the formed oil film thickness decreases, and the lubrication state changes from fluid lubrication to mixed lubrication and boundary lubrication, and a state occurs in which the main shaft and the inner surface of the journal bearing are in direct contact. The reliability was impaired.

The refrigerant HCFC22 which has been conventionally used exhibits a lubricating effect as an extreme pressure agent by containing chlorine atoms in the molecule, and has very good friction and wear resistance characteristics. Further, the mineral oil used as the refrigerating machine oil was a refrigerating machine oil having excellent wear resistance and seizure resistance. Thus, the lubricating properties of the conventional refrigerant and refrigerating machine oil were high. For this reason, even if the lubrication state of the journal bearing changes from a fluid lubrication state to a mixed lubrication state and a boundary lubrication state, large wear did not occur and reliability was not impaired.

[0013]

In the future, from the viewpoint of protecting the global environment, in particular, the protection of the ozone layer and the prevention of global warming, a refrigerant for air conditioners, HCFC22, which has been conventionally used, is replaced with a hydrofluorocarbon (HFCs) refrigerant containing no chlorine atom. Alternatively, it is necessary to switch to a natural refrigerant such as hydrocarbon (HC) and carbon dioxide (CO2). However, since the HFCs refrigerant and the natural refrigerant do not contain a chlorine atom in the molecule, they have a poor lubrication effect as an extreme pressure agent, and the wear resistance and seizure resistance are extremely deteriorated. The refrigerating machine oil used at this time is a polyol ester (POE) from the viewpoint that compatibility with the HFCs refrigerant and the natural refrigerant is necessary.
We are considering using oil. This refrigerating machine oil has significantly deteriorated wear and seizure resistance as compared with conventional mineral oil.

Under such a severe sliding atmosphere with poor lubricity, the conventional configuration described above reduces the viscosity coefficient of the oil, the main shaft rotation speed, the bearing width, etc. in order to increase the efficiency of the compressor. Alternatively, the bearing gap is increased to reduce the oil film thickness, that is, by reducing the oil film thickness parameter value 減少, thereby reducing the friction coefficient and reducing the sliding loss of the bearing. However, the oil film thickness parameter value Λ
If the oil content is excessively reduced, the formed oil film thickness decreases, and the lubrication state changes from fluid lubrication to mixed lubrication and boundary lubrication, which not only increases sliding loss but also increases wear and impairs reliability. .

Further, in the above-mentioned conventional configuration, since the compression mechanism portion is configured to protrude in the axial direction from the journal bearing supporting the main shaft, a moment is applied to the bearing by a load acting on the movable scroll, and the moment in the bearing is reduced. The inclination of the shaft occurred, and the phenomenon of one-side contact occurred. For this reason, the load distribution is not uniform in the axial direction of the bearing, and the load tends to be extremely high at the bearing end. As a result, surface damage, such as wear, was likely to occur near the bearing end due to direct contact with the main shaft. As a result, sliding loss and wear increase, which not only reduces the efficiency of the compressor but also impairs reliability.

The present invention solves the above-mentioned conventional problems, and enables high efficiency and high reliability by reducing the sliding loss of the journal bearing portion under the sliding atmosphere of HFCs refrigerant or natural refrigerant. An object is to provide a compressor.

[0017]

According to a first aspect of the present invention, there is provided a compression mechanism, a main shaft for driving the compression mechanism, and a support for the main shaft. A journal bearing, and an electric motor including a rotor attached to the main shaft and a stator attached to the hermetic container. The oil film thickness parameter value 表 わ す representing the bearing characteristics of the journal bearing is Λ> 3.3. A compressor characterized in that:

According to a second aspect of the present invention, the surface roughness Ra of the shaft of the journal bearing is Ra ≦ 0.2, and the surface roughness Ra of the bearing is Ra ≦ 0.3. Machine.

According to a third aspect of the present invention, there is provided a compression mechanism, a main shaft for driving the compression mechanism, inside a closed container;
Compression characterized by comprising a journal bearing portion for supporting the main shaft, an electric motor including a rotor attached to the main shaft and a stator attached to the closed container, and a crowning formed at an end of the journal bearing portion. Machine.

According to a fourth aspect of the present invention, in the compressor according to the third aspect, a carbon bushing material, a resin bushing material, a resin composite bearing material with a backing metal, a metal bearing material with a backing metal, or a cast iron material is used for the journal bearing portion. It is.

According to a fifth aspect of the present invention, there is provided the compressor according to the third aspect, wherein a crowning is formed at one or both ends of the journal bearing.

According to a sixth aspect of the present invention, an oil film thickness parameter value を representing the bearing characteristics of the journal bearing portion is set to Λ>
The compressor according to any one of claims 3 to 5, wherein the compressor is 3.3.

According to a seventh aspect of the present invention, there is provided the method according to any one of the first to sixth aspects, wherein a hydrofluorocarbon (HFCs) refrigerant is used as a working fluid, and an alkylbenzene oil or a mineral oil having poor solubility in the HFCs refrigerant is used as a refrigerating machine oil. It is a compressor of the description.

The present invention according to claim 8 is characterized in that a hydrofluorocarbon (HFCs) refrigerant is used as a working fluid, and an HFCs such as an ester oil or an ether oil is used as a refrigerating machine oil.
The compressor according to any one of claims 1 to 6, wherein a compatible oil for the refrigerant is used.

According to a ninth aspect of the present invention, the working fluid is a hydrocarbon (HC) refrigerant or carbon dioxide (CO2).
The compressor according to any one of claims 1 to 6, wherein a refrigerant is used.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Some embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 is a sectional view of a main part of a journal bearing for a compressor according to a first embodiment of the present invention. Here, the journal bearing for a compressor shown in FIG.
Since it is a journal bearing for the main shaft of the scroll compressor, the configuration of the compressor other than the journal bearing is the same as that of the conventional scroll compressor described in detail with reference to FIG. use. The description of the same configuration and operation as in the conventional example will be omitted.

The journal bearing 25 is formed by shrink-fitting an annular carbon bushing material 26 to the bearing component 4 and fixing it. The carbon bushing material is formed by impregnating a ring-shaped carbon material sintered with a metal element such as Pb, Sb, Sn, or Cu, and then grinding and polishing the sliding surface to finish. The thickness of the annular carbon bush material 26 was 3.5 mm. The cast iron material FC2 is used for the main shaft 5 and the bearing component 4.
The surface hardness of the sliding portion of the main shaft 5 is increased by induction hardening.

The journal bearing for a compressor according to the present invention has a bearing specification (for example, shaft diameter D = 33 mm, bearing width L = 1).
5.8 mm, gap ratio ψ = 0.0027, shaft surface roughness R
a = 0.2 μm, carbon bushing surface roughness Ra =
0.3 μm), the oil film thickness h of the journal bearing under various rated operating conditions of the scroll compressor becomes h> 1.7 μm, and the oil film thickness parameter value Λ
Is set to satisfy Λ> 3.3.

Next, the operation of the journal bearing for a compressor having the above configuration will be described. By rotating the movable scroll 2b so as not to rotate with respect to the fixed scroll (not shown), the fixed scroll and the movable scroll 2b are rotated.
The plurality of compression spaces formed between b are gradually reduced from the outside to the inside to perform compression. The compressed gas becomes a high pressure gas. A radial load acts on the orbiting scroll due to a radial component of the high gas pressure, an inertial force, and the like. This load is supported by the journal bearing 25 via the eccentric bearing 6.

As described above, the main shaft 5 made of the cast iron material is
Due to the extremely large load generated due to gas compression and the like, the journal bearing 25 rotates while being pressed against the inner surface thereof, so that the rotation of the main shaft reduces the thickness of the oil film formed inside the bearing, and the lubrication state becomes extremely large. It becomes severe and tends to shift to a state where the main shaft and the inner surface of the journal bearing are in direct contact, that is, a mixed lubrication or boundary lubrication state.

However, in this embodiment, the journal bearing 2 under various rated operating conditions of the scroll compressor is used.
5, the oil film thickness h becomes h> 1.7 μm, and the oil film thickness parameter value Λ becomes Λ> 3.3.

The present inventors have confirmed the new facts and effects obtained by the above-described configuration or means based on the following experiments.

Using a refrigerant (HFC410A) and a refrigerating machine oil (POE oil), a scroll compressor of a home air conditioner is operated under various operating conditions, and the lubrication state of the journal bearing is changed to an electrical contact by a voltage application method. evaluated. The voltage application circuit applies an electric potential between the bushing material of the journal bearing and the main shaft, and when the contact is in a non-contact state, the voltage is approximately 0.1 V.
09V, which was set to be almost 0V in the contact state. In the actual measurement, the non-contact state is set to 0.08 to 0.
09V.

FIG. 2 shows the relationship between the voltage between the journal bearing bush material and the main shaft and the minimum oil film thickness obtained from the lubrication theory analysis when the rated operating conditions, operating frequency and discharge pressure of the scroll compressor were changed. .

In FIG. 2, experimental points when the rated operating conditions, the operating frequency, and the discharge pressure are changed are indicated by circles, triangles, and squares, respectively. From this result, as the oil film thickness decreases, the voltage between the bush material and the main shaft of the journal bearing rapidly decreases with the minimum oil film thickness of 1.7 μm as a threshold value regardless of operating conditions. You can see that. That is, it has been found that the lubrication state of the journal bearing shifts from the fluid lubrication state to the mixed lubrication state and the boundary lubrication state on the basis of the oil film thickness. The surface roughness Ra of the main shaft of this journal bearing was 0.2 μm, the surface roughness Ra of the carbon bushing material was 0.3 μm, and the combined roughness of the two surfaces was 0.51 μm. Therefore, the oil film thickness parameter value Λ in this case was approximately Λ = 3.3.

From the above experimental results, it was found that when the oil film thickness parameter value Λ becomes Λ <3.3, the lubrication state deviates from the fluid lubrication state. That is, the lubrication state of the journal bearing has shifted to the mixed lubrication and boundary lubrication state. When the oil film thickness parameter value Λ is Λ> 3.3, the lubrication state of the journal bearing is close to the fluid lubrication state, so that the friction coefficient is low, that is, the sliding loss in the journal bearing is small. I understand.

As described above, according to the present embodiment, even when an alternative refrigerant having poor lubricity and a corresponding refrigerating machine oil are used, the reliability is not impaired due to abrasion.
The sliding loss in the journal bearing can be reduced, and the efficiency of the compressor can be significantly increased.

Surface roughness Ra of the spindle of the journal bearing
= 0.2 μm, surface roughness Ra = 0.
When the surface roughness was further improved, the oil film thickness parameter value Λ increased even with the same minimum oil film thickness. Generation can be prevented and high reliability can be ensured. Further, although the gray cast iron material FC250 is used as the material of the shaft, a similar effect can be obtained when steel materials S45C, SCM415 and the like are used.

In the first embodiment, the structure of the journal bearing for the scroll compressor has been described. However, the same effect can be obtained with journal bearings of other compressors such as a reciprocating compressor and a rotary compressor. can get.

In this embodiment, HFC4 is used as the refrigerant.
10A, an alkylbenzene oil (having a viscosity of 31.3 mm2) having poor solubility in the refrigerant HFC410A in the refrigerating machine oil.
/ S ＠ 40 ° C.). As described above, by using the refrigerating machine oil having low solubility in the refrigerant, the oil film formed in the gap between the main shaft and the bearing is difficult to dissolve in the refrigerant, and thus is not easily washed away. Further, the viscosity of the lubricating oil is slightly reduced because it is hardly dissolved in the refrigerant. Therefore, the oil film is broken and the main shaft and the inner surface of the journal bearing do not come into direct contact with each other, so that sliding loss and reliability can be improved.

As a refrigerating machine oil, a mineral oil having a poor solubility in HFCs refrigerant (viscosity 32 mm2 / s ／ 40)
C.), the same effect can be obtained.

Further, even when an ester oil or an ether oil compatible with the HFCs refrigerant is used as the refrigerating machine oil, the use of the journal bearing of the present embodiment can reduce the sliding loss and significantly improve the reliability. It goes without saying that it can be improved.

Further, when HC refrigerant is used as the refrigerant and mineral oil or alkylbenzene oil having high solubility in the HC refrigerant is used as the refrigerating machine oil, the viscosity of the refrigerating machine oil is remarkably reduced, and the sliding conditions of the journal bearing are more severe. However, by employing the journal bearing for a compressor of the present embodiment, it is possible to improve the wear resistance and to obtain high reliability. When the CO2 refrigerant is used as the refrigerant, the load acting on the bearing becomes extremely large, so that the sliding condition of the journal bearing becomes more severe, but by employing the journal bearing for a compressor of the present embodiment,
Similar effects can be obtained.

(Embodiment 2) Hereinafter, a second embodiment of the present invention will be described with reference to the drawings.

FIG. 3 is a longitudinal sectional view of a bush material of a journal bearing for a compressor according to a second embodiment of the present invention. In the first embodiment, an annular carbon bushing material is used, but in the present embodiment, an arc-shaped crowning 28 is provided at both ends of the bearing of the polyimide resin bushing 27. The inner and outer diameter dimensions and the bearing width of the bush 27 made of a polyimide resin are the same as those of the bush used in the first embodiment. At both ends of a bushing material 27 of a 3.5 mm-thick annular polyimide resin, a width of 3 to 5 mm and a radius R
Form an arc of R> 500 mm, and crowning 28
And When the radius R of the arc portion is R <500, the gap formed between the shaft and the bushing material at the bearing end surface becomes too large, so that an oil film is less likely to be formed. Therefore, the radius R of the arc is R
> 500 is desirable.

Further, in this embodiment, the specifications of the bearing (for example, shaft diameter D = 33 mm, bearing width L = 15.8 mm, gap ratio ψ = 0.0027, shaft surface roughness Ra = 0.2 μm,
By selecting the surface roughness Ra of the carbon bushing material (Ra = 0.3 μm), the average oil film thickness h of the journal bearing under various operating conditions of the scroll compressor is h> 1.7 μm.
m, and the average oil film thickness parameter value Λ is greater than 3.3.

As described above, the journal bearing is provided with the arc-shaped crowning 28 at both ends of the bearing, and the bushing material at the end of the bearing is formed with the arc-shaped crowning. Therefore, even if the main shaft is bent or tilted in the above, the contact stress between the main shaft and the bearing bush at the bearing end can be reduced. For this reason, there is no possibility that the vicinity of the bearing end directly contacts the main shaft to damage the surface, and the fluid lubrication state can be maintained. Further, since the average oil film thickness parameter value Λ of the journal bearing is set to satisfy Λ> 3.3, the lubrication state can be changed to the fluid lubrication state in the entire region of the journal bearing. Therefore, a journal bearing having a low coefficient of friction and a small sliding loss can be realized.

When the crowning is provided only at one end of the annular carbon bush material on the compression mechanism 2 side,
It goes without saying that a similar effect can be obtained.

Further, in this embodiment, since the bushing material of the polyimide resin is used as the bushing material, the bushing material is less brittle as compared with the carbon bushing material of the above-described embodiment, the chipping of the end of the bushing material is eliminated, and the bushing material is eliminated. Can be press-fitted into the bearing component 4, and productivity is greatly increased. In other words, a journal bearing with low sliding loss and high reliability can be realized very easily due to the construction method. Further, even when the journal bearing portion is formed directly on the bearing component 4 made of a cast iron material without using a bush material, the same effect can be obtained by adopting the present embodiment, and further cost reduction can be achieved. Becomes possible.

(Embodiment 3) A third embodiment of the present invention will be described below with reference to the drawings.

FIG. 4 is a longitudinal sectional view of a bush member of a journal bearing for a compressor according to a third embodiment of the present invention. The difference from the first embodiment is that a resin composite bearing material 29 with back metal is used for the journal bearing portion, and a linear crowning 33 is formed on the resin layer 32 at both ends of the bearing. The resin composite bearing material 29 with back metal has a plate thickness of 1.
A 35 mm steel plate is used for the back metal 30, and a porous sintered layer 31 and a resin layer 32 are formed on the steel plate. The crowning 33 provided at both ends of the bearing of the resin layer 32 has a width of 3 to 5 mm and has a tapered (linear) shape.
The thickness of the resin layer is reduced by 10μ at the bearing end.
m or less.

Further, in this embodiment, the specifications of the bearing (for example, shaft diameter D = 33 mm, bearing width L = 15.8 mm, clearance ratio ψ = 0.0027, shaft surface roughness Ra = 0.2 μm,
By selecting the surface roughness Ra of the carbon bushing material (Ra = 0.3 μm), the average oil film thickness h of the journal bearing under various operating conditions of the scroll compressor is h> 1.7 μm.
m, and the average oil film thickness parameter value Λ is greater than 3.3.

As described above, the resin composite bearing with back metal is used as a journal bearing material, the thickness of the resin layer at both ends of the bearing is reduced, and a linear crowning is formed on the bush material at the bearing end. Therefore, even when a moment is applied to the main shaft and the main shaft bends or tilts in the bearing, the contact stress between the main shaft and the bearing bush can be reduced. For this reason, there is no possibility that the vicinity of the bearing end directly contacts the main shaft to damage the surface, and the fluid lubrication state can be maintained. Further, since the average oil film thickness parameter value Λ of the journal bearing is set to satisfy Λ> 3.3, the lubrication state can be changed to the fluid lubrication state in the entire region of the journal bearing. Therefore, a journal bearing having a low coefficient of friction and a small sliding loss can be realized.

Further, since a resin composite bearing with a back metal is used for the bush material, mass production of the bush material is facilitated.
Very low bearing cost. Needless to say, the bushing material can be press-fitted into the bearing component, and the productivity is greatly increased.
From the above, it is possible to realize a highly reliable journal bearing that is extremely easy in terms of construction method, low in cost, low in sliding loss, and low in cost.

In this embodiment, the case where the resin composite bearing material with the back metal is used for the bush material has been described. However, the present invention is not limited to this.
Alternatively, a similar effect can be obtained in the case of a cast iron bearing material.
Further, the resin composite bearing material with a back metal may be a material in which a layer in which a resin layer 32 is impregnated in a porous sintered layer 31 formed on the back metal is formed.

[0057]

As is apparent from the above description, the present invention can be applied to a journal bearing portion of a compressor even if a HFCs refrigerant or a natural refrigerant having no abrasion resistance and containing no chlorine atom in the molecule is used. Sliding loss can be reduced without causing surface damage such as abrasion due to direct contact, and there is an advantage that a compressor with high efficiency and high reliability can be provided.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of a journal bearing for a compressor according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a journal bearing test result.

FIG. 3 is a longitudinal sectional view of a bush material of a journal bearing for a compressor according to a second embodiment of the present invention.

FIG. 4 is a longitudinal sectional view of a bush material of a journal bearing for a compressor according to a third embodiment of the present invention.

FIG. 5 is a longitudinal sectional view of a conventional scroll compressor.

[Explanation of symbols]

 Reference Signs List 4 bearing parts 5 main shaft 6 eccentric bearing 25 journal bearing 26 carbon bushing material 27 bushing material of polyimide resin 28, 33 crowning 29 resin composite bearing material with backing metal 30 backing metal 31 porous sintered layer 32 resin layer

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F04C 29/00 F04C 29/00 H 29/02 29/02 B F16C 33/10 F16C 33/10 Z 33 / 12 33/12 Z 33/20 33/20 A 33/24 33/24 Z (72) Inventor Hiroyuki Fukuhara 1006 Ojidoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. F term (reference) 3H003 AA05 AB03 AC03 AD02 AD03 BD09 CA02 3H029 AA02 AA14 AA21 AB03 BB01 BB42 BB50 CC16 CC17 CC33 CC39 3H039 AA03 AA06 AA12 BB04 BB11 BB28 CC12 CC19 CC35 CC41 3J011 AA06 AA20 BA02 DA01 JA02 KA02 KA03 LA03 MA05 PA02 SB03

Claims (9)

[Claims] 1. A compression mechanism, a main shaft for driving the compression mechanism, a journal bearing for supporting the main shaft, a rotor mounted on the main shaft, and a stator mounted on the closed container inside the closed container. Wherein the oil film thickness parameter value を representing the bearing characteristics of the journal bearing portion is set to Λ> 3.3. 2. The surface roughness Ra of the shaft of the journal bearing portion.
2. The compressor according to claim 1, wherein Ra ≦ 0.2 and the surface roughness Ra of the bearing Ra ≦ 0.3. 3. A compression mechanism, a main shaft for driving the compression mechanism, a journal bearing for supporting the main shaft, a rotor mounted on the main shaft, and a stator mounted on the closed container inside the closed container. Wherein each of the motors includes a motor, and a crowning is formed at an end of the journal bearing portion. 4. The compressor according to claim 3, wherein a carbon bushing material, a resin bushing material, a resin composite bearing material with a backing metal, a metal bearing material with a backing metal, or a cast iron material is used for the journal bearing portion. 5. The compressor according to claim 3, wherein a crowning is formed at one end or both ends of said journal bearing portion. 6. The compressor according to claim 3, wherein an oil film thickness parameter value を representing a bearing characteristic of the journal bearing portion is set to Λ> 3.3. 7. The compressor according to claim 1, wherein a hydrofluorocarbon (HFCs) refrigerant is used as a working fluid, and an alkylbenzene oil or a mineral oil having poor solubility in the HFCs refrigerant is used as a refrigerating machine oil. 8. The compressor according to claim 1, wherein a hydrofluorocarbon (HFCs) refrigerant is used as a working fluid, and an oil compatible with the HFCs refrigerant, such as an ester oil or an ether oil, is used as a refrigerating machine oil. 9. The compressor according to claim 1, wherein a hydrocarbon (HC) refrigerant or a carbon dioxide (CO2) refrigerant is used as a working fluid.