JP2001065458A - Compressor - Google Patents

Abstract

(57) [Problem] To slide without causing surface damage such as abrasion due to direct contact with a journal bearing portion of a compressor even when using HFCs refrigerant or natural refrigerant which does not contain chlorine and has low wear resistance. A dynamic loss can be reduced, and a highly efficient and reliable compressor is provided. SOLUTION: The rigidity of both ends of the journal bearing portion of the compressor journal bearing portion is reduced, and the Sommerfeld value S representing the bearing characteristics of the journal bearing portion is set to S>
0.04.

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, there are reciprocating compressors, rotary compressors and scroll compressors, all of which are used in home and commercial air conditioning. 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. As a scroll compressor used for air conditioning, a scroll compressor disclosed in JP-A-6-307356 is known.

FIG. 7 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 is located below the spacer 22 inside the closed container 1,
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 13 for supplying the lubricating oil 9 to each bearing portion, that is, the journal bearing 8, the eccentric bearing 6, and the thrust bearing 3.
And an oil guide 14 is press-fitted or shrink-fitted and fixed to the lower end of the main shaft 5 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 relative to the fixed scroll 2a. An Oldham ring 21 for preventing rotation is a suction port provided in the bearing component 4 for sucking low-pressure gas into the compression mechanism 2.

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.

A radial load acts on the orbiting scroll due to a radial component of gas pressure in the compression chamber, an inertial force, and the like. This load rotates in the same direction as the rotation of the main shaft 5 and acts on the journal bearing 8 via the eccentric bearing 6.
Supported by That is, the main shaft 5 made of cast iron material is
With a very large load generated by gas compression or the like, the journal bearing 8 rotates while being pressed against the inner surface thereof. 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. An oil film is formed between the main shaft and the journal bearing inner surface, so that the main shaft and the journal bearing inner surface are not in direct contact,
That is, the lubrication state was a fluid lubrication state, and no great wear occurred.

Generally, the friction coefficient of a journal bearing has a correlation with the Sommerfeld value S representing the bearing characteristics.
The Sommerfeld value S is represented by μ representing the viscosity coefficient of the lubricating oil, N representing the rotational speed of the main shaft, D representing the shaft diameter, L representing the bearing width, W representing the load acting on the bearing, and 比 representing the ratio between the bearing clearance and the shaft diameter D. Then, it is expressed by the following equation (Equation 1).

[0009]

(Equation 1)

In the fluid lubrication state, the smaller the Sommerfeld value S is, the smaller the friction coefficient is, and the sliding loss in the journal bearing is also reduced. Therefore, a design is made to reduce the Sommerfeld value S, and the mechanical loss of the compressor is reduced. Reduction and higher efficiency. However, when the Sommerfeld value S is excessively reduced, the formed oil film thickness decreases,
The lubrication state has changed from fluid lubrication to mixed lubrication and boundary lubrication, and a state has occurred in which the main shaft and the inner surface of the journal bearing are in direct contact.

The conventionally used refrigerant HCFC22 exerts 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.

[0012]

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 above-mentioned conventional structure reduces the oil viscosity coefficient, the main shaft rotation speed, the bearing width, etc. in order to increase the efficiency of the compressor. Alternatively, the sliding loss of the bearing is reduced by increasing the bearing clearance, that is, reducing the Sommerfeld value S to reduce the friction coefficient. However, if the Sommerfeld value S is excessively reduced, the formed oil film thickness decreases, and the lubrication state changes from fluid lubrication to mixed lubrication and boundary lubrication, and not only sliding loss increases, but also
This has led to increased wear and reduced reliability.

Further, in the above-described 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 a moment in the bearing is generated. The axis was tilted. For this reason, the load distribution is not uniform in the axial direction of the bearing, and the load tends to increase 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.

[0016]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, according to the present invention, a compression mechanism, a main shaft for driving the compression mechanism, and a journal bearing for supporting the main shaft are provided in a closed container. And a motor including a rotor attached to the main shaft and a stator attached to the closed casing, and a Sommerfeld value S representing a bearing characteristic of the journal bearing portion is set to S> 0.04. It is a compressor characterized by.

According to a second aspect of the present invention, 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 An electric motor including a motor including a stator attached to a container, wherein the journal bearing portion is made of a carbon bush material or a resin bush material, and an annular slit is provided at a bearing end.

According to a third aspect of the present invention, a compression mechanism, a main shaft for driving the compression mechanism, a journal bearing for supporting the main shaft, a rotor attached to the main shaft, and It is provided that each of the motors includes a stator attached to a container, and that the journal bearing portion is made of a resin composite bearing material with a backing metal or a metal bearing material with a backing metal, and that the thickness of the backing metal at the bearing end is made thinner than the center of the bearing. It is a compressor characterized by.

According to a fourth aspect of the present invention, there is provided a compression mechanism, a main shaft for driving the compression mechanism, a journal bearing for supporting the main shaft, and a bearing component for installing the journal bearing in the closed container. An electric motor including a rotor attached to the main shaft and a stator attached to the airtight container, wherein a carbon bushing material or a resin bushing material is used for the journal bearing portion, and the carbon bushing material or the resin bushing at a bearing end is provided. The compressor is characterized in that the plate thickness of the material is made thinner than the center part of the bearing, and a gap is provided between the journal bearing part and the bearing part at the bearing end.

According to a fifth aspect of the present invention, a Sommerfeld value S representing a bearing characteristic of a journal bearing portion is set so that S>
5. The compressor according to claim 2, wherein said compressor is 0.04.

[0021]

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.
Because it is a journal bearing for the main shaft of a 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. 7, and the same numbers are used for the same functional parts. 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).
By selecting 5.8 mm and a gap ratio of ψ = 0.002), the sommer felt value S of the journal bearing under various operating conditions of the scroll compressor is set to satisfy S> 0.04.

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.

Thus, the main shaft 5 made of 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 the present embodiment, since the Sommerfeld value S of the journal bearing 25 under the various operating conditions of the scroll compressor is set to S> 0.04, the following operation occurs.

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

A journal bearing test was performed in a coexisting atmosphere of a refrigerant (HFC134a) and a refrigerating machine oil (alkylbenzene oil). The rotational speed of the shaft and the viscosity of the refrigerating machine oil were changed, and the correlation between the friction coefficient f of the bearing, the ratio f / ψ of the clearance ratio ψ, and the Sommerfeld number S was evaluated. A gray cast iron material was used as a material of the shaft and the journal bearing, and the surface roughness of each sliding surface was the same as that of the shaft and the journal bearing of the compressor.

FIG. 2 shows the relationship between the friction coefficient f of the bearing, the ratio f / ψ of the gap ratio ψ, and the Sommerfeld number S obtained from the above experiment. In FIG. 2, the experimental results are indicated by circles and the theoretical analysis results of fluid lubrication are indicated by solid lines. An arrow ↑ attached to a circle representing an experimental result indicates a case where a steady friction coefficient was not obtained and the friction coefficient sharply increased during the test.
From this result, when the Sommerfeld number S becomes S <0.04, the lubrication state deviates from the fluid lubrication state,
It was found that the coefficient of friction increased sharply. That is, the lubrication state has shifted to the mixed lubrication state and the boundary lubrication state. When the Sommerfeld number S is S> 0.04,
The lubricating state was a state close to the fluid lubricating state, and it was found that the friction coefficient was low, that is, the sliding loss in the journal bearing was small.

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

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. It goes without saying that you can get it.

In this embodiment, HFC1 is used as the refrigerant.
34a is an alkylbenzene oil (having a viscosity of 31.3 mm 2) having poor solubility in the refrigerant HFC134a 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 hardly decreases because it hardly dissolves 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 of 32 mm2 / sｓ40)
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 this embodiment can reduce the sliding loss and significantly improve the reliability. It goes without saying that it can be improved.

Further, when an HC refrigerant is used as the refrigerant and a mineral oil or an 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 bush material is used, but in the present embodiment, annular slits 28 are provided at both ends of the bearing of the polyimide resin bush material 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. An annular slit 28 having a thickness of 1 mm and a depth of 2 mm is formed at both ends of an annular polyimide resin bushing material 27 having a thickness of 3.5 mm. Further, in the present embodiment, the specifications of the bearing (for example, shaft diameter D = 33 mm, bearing width L =
By selecting 15.8 mm and the gap ratio ψ = 0.002), the sommer felt value S of the journal bearing under various operating conditions of the scroll compressor is set to satisfy S> 0.04.

As described above, since the annular slit 28 is provided at both ends of the journal bearing, the rigidity of the bearing at the end of the bearing is reduced. Therefore, when a moment is applied to the main shaft and the main shaft tilts in the bearing, and the load distribution becomes large at the bearing end, the bush material at the bearing end is deformed and the contact stress between the main shaft and the bearing bush is increased. 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,
When the sommer felt value S of the journal bearing is S> 0.0
4, 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.

It is needless to say that the same effect can be obtained even when annular slits are provided at both ends of the bearing of the annular carbon bush material.

Further, in this embodiment, since the bush material made of a polyimide resin is used as the bush material, the bush material is less brittle than the carbon bush material of the above-described embodiment, and the end of the bush material is not chipped and the bush material is not broken. 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.

(Embodiment 3) Hereinafter, a third embodiment of the present invention will be described 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 a back metal is used for the journal bearing portion, and the thickness of the back metal 30 at both ends of the bearing is made thinner than the center portion. The resin composite bearing member 29 with a back metal is a steel plate having a plate thickness of 1.35 mm used as the back metal 30 and a porous sintered layer 31 and a resin layer 32 formed on the steel plate. The thickness of the back metal 30 at both ends of the bearing is 0.65 mm, and the thickness of the back metal 30 is tapered from the center of the back metal having a thickness of 1.35 mm.

Further, in the present embodiment, by selecting the specifications of the bearing (for example, shaft diameter D = 33 mm, bearing width L = 15.8 mm, clearance ratio 隙間 = 0.002), various operations of the scroll compressor are performed. The configuration is such that the Sommerfeld value S of the journal bearing under the condition is S> 0.04.

As described above, since the resin composite bearing with the back metal is used as the journal bearing material and the thickness of the back metal at both ends of the bearing is reduced, the rigidity of the bearing at the end of the bearing is reduced. Therefore, when a moment is applied to the main shaft and the main shaft tilts in the bearing, and the load distribution becomes large at the bearing end, the bush material at the bearing end is deformed and the contact stress between the main shaft and the bearing bush is increased. 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 sommer felt value S of the journal bearing is set to satisfy S> 0.04, 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 the present 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. For example, the same effect can be obtained in the case of the metal bearing material with the back metal having the back metal. . Further, in the present embodiment, the thickness of the back metal 30 is reduced in a tapered manner from the center of the back metal. 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.

(Embodiment 4) Hereinafter, a fourth embodiment of the present invention will be described with reference to the drawings.

FIG. 5 is a sectional view of a main part of a journal bearing for a compressor according to a fourth embodiment of the present invention. FIG. 5 is a longitudinal section of a bush member of the journal bearing for a compressor according to the fourth embodiment of the present invention. FIG. The difference from the second and third embodiments is that a bush member 34 made of a polyimide resin is used for the journal bearing 33, and the resin thickness at both ends of the bearing is smaller than that at the center. The thickness of the bush 33 made of a polyimide resin is 3.5 mm in the central part, and the resin thickness is tapered toward the end of the bearing.
The bush member 33 is press-fitted into the bearing component 4 and fixedly attached. Since the bush member 33 has a configuration in which the resin thickness at both ends of the bearing is smaller than that at the center, a gap 35 is formed between the bearing component 4 and the outer peripheral surface of the bush member 33 at both ends of the bearing.

Further, in the present embodiment, by selecting the specifications of the bearing (for example, shaft diameter D = 33 mm, bearing width L = 15.8 mm, clearance ratio 隙間 = 0.002), various operations of the scroll compressor can be performed. The configuration is such that the Sommerfeld value S of the journal bearing under the condition is S> 0.04.

As described above, since the bushing material of the polyimide resin is used as the journal bearing material and the resin thickness at both ends of the bearing is reduced, the rigidity of the bearing portion at the bearing end is reduced. Therefore, when a moment is applied to the main shaft and the main shaft tilts in the bearing, and the load distribution becomes large at the bearing end, the bush material at the bearing end is deformed and the contact stress between the main shaft and the bearing bush is increased. 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 sommer felt value S of the journal bearing is set to satisfy S> 0.04, 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, in this embodiment, it is needless to say that, in this embodiment, the working of the bearing material is facilitated, so that the productivity is greatly increased.

From the above, it is possible to realize a highly reliable journal bearing with extremely low sliding loss and high reliability at a low cost at a very low cost.

It is needless to say that the same effect can be obtained when an annular carbon bushing material is used as the bushing material, or when a bearing resin material other than the polyimide resin is used.

[0055]

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 sectional view of a main part of a journal bearing for a compressor according to a fourth embodiment of the present invention.

FIG. 6 is a longitudinal sectional view of a bush material of a journal bearing for a compressor according to a fourth embodiment of the present invention.

FIG. 7 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, 33 journal bearing 26 carbon bushing material 27, 34 bushing material of polyimide resin 28 annular slit 29 resin composite bearing material with backing metal 30 backing metal 31 porous sintered layer 32 resin layer 35 gap

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Mitsuharu Matsuo 1006 Kazuma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. F term (reference) 3H003 AA01 AB03 AC03 AD01 AD02 AD03 BD02 BD09 CA02 3H029 AA02 AA14 AB03 BB44 CC18 CC38 CC39 CC40 3H039 AA03 AA04 BB04 CC02 CC03 CC10 CC35 3J011 CA01 CA04 LA01 QA04 QA05 SC01 SE02

Claims (8)

[Claims] 1. A compression mechanism inside a closed container, 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. , Wherein the Sommerfeld value S representing the bearing characteristics of the journal bearing portion is S> 0.04. 2. 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 journal bearing portion is made of a carbon bushing material or a resin bushing material, and an annular slit is provided at a bearing end. 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 hermetic container. Wherein each of the journal bearings is made of a resin composite bearing material with a backing metal or a metal bearing material with a backing metal, and the thickness of the backing metal at the end of the bearing is made thinner than that at the center of the bearing. 4. A compression mechanism, a main shaft for driving the compression mechanism, a journal bearing for supporting the main shaft, a bearing component for installing the journal bearing, and a bearing component for mounting the journal bearing inside the closed container. A motor including a rotor and a stator attached to the hermetic container; and a carbon bushing material or a resin bushing material used for the journal bearing portion, and the plate thickness of the carbon bushing material or the resin bushing material at the bearing end is adjusted. A journal bearing for a compressor, wherein the journal bearing is thinner than a center portion and a gap is provided between the journal bearing portion and a bearing component at a bearing end. 5. A sommer felt value S representing a bearing characteristic of a journal bearing portion is set to S> 0.04.
A compressor according to any one of the preceding claims. 6. 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. 7. 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. . 8. The method according to claim 1, wherein a hydrocarbon (HC) refrigerant or a carbon dioxide refrigerant (CO2) is used as the working fluid.
A compressor according to any one of the preceding claims.