WO2022176505A1 - Compressor, and refrigeration device employing same - Google Patents

Abstract

According to the present invention, a rotary compressor is provided with an electrically driven mechanism unit, a compression mechanism unit, and an oil storage unit, inside a hermetically sealed container, for example. The compression mechanism unit includes a rotating shaft and a journal bearing member having a bearing (35), which are in sliding rotation with lubricating oil interposed therebetween. In the compression mechanism unit, a right-handed helical groove (61) and a left-handed helical groove (62) are additionally formed in at least one of an outer circumference of the rotating shaft or an inner circumference of the bearing (35). It is thus possible to promote the formation of an oil film in a gap between the rotating shaft and the bearing (35), and to promote discharge of abrasion powder from the gap between the rotating shaft and the bearing, even if there is an increase in surface pressure or when a low viscosity lubricating oil is being used. Seizure or wear accompanying direct contact sliding is thus suppressed, and the performance and reliability of the compressor can therefore be improved.

Description

Compressor and refrigeration equipment using the same

The present disclosure relates to a compressor and a refrigeration system using a refrigeration cycle device such as an air conditioner, a water heater, and a refrigerator using the same.

Patent Document 1 discloses a rotary compressor used in air conditioners and the like. This rotary compressor incorporates a compression mechanism and an electric mechanism for driving the compression mechanism in a sealed container. One end of a rotary shaft is connected and fixed to the stator of the electric mechanism, and the other end of the rotary shaft is provided with a piston roller that rotates eccentrically within the cylinder of the compression mechanism.

A journal bearing is a bearing structure that supports the rotating shaft of a rotary compressor. A journal bearing supports a rotating shaft through a film of lubricating oil. The rotating shaft rotates while being strongly pressed against the inner peripheral surface of the journal bearing due to the large load generated by the compression of the refrigerant.

Both the rotating shaft and journal bearing have unevenness or undulations on their surfaces. When these uneven or undulating surfaces come close to each other, even if the average film thickness of the lubricating oil is constant, the flow transition from the fluid lubrication region to the mixed lubrication region and further to the boundary lubrication region where solid contact mainly occurs. Transitions can occur. Such transition of the lubricating region may lead to an increase in frictional resistance or wear between the journal bearing and the rotating shaft.

Therefore, for example, in Patent Document 1, the surface roughness σa of at least the portion of the rotating shaft that slides on the journal bearing satisfies the following formula (1), and the surface roughness σb of the journal bearing in formula (1) is 1 .mu.m, and the surface roughness .sigma.a of at least the portion of the rotating shaft that slides on the journal bearing is smaller than 0.7 .mu.m.

 
　なお、上記数式（１）における「ｈｓ」は最小油膜厚さであり、「σａ」は回転軸の表面粗さであり、「σｂ」はジャーナル軸受の表面粗さである。

Note that "hs" in the above equation (1) is the minimum oil film thickness, "σa" is the surface roughness of the rotating shaft, and "σb" is the surface roughness of the journal bearing.

JP 2009-275645 A

The present disclosure is a compressor that improves operational efficiency and reliability by suppressing or avoiding seizure or abnormal wear due to lack of oil film or entrapment of wear debris between a rotating shaft and a bearing. It is another object of the present invention to provide a refrigerating apparatus using the same.

In order to solve the above-described problems, the compressor according to the present disclosure includes an electric mechanism, a compression mechanism, and an oil reservoir in a closed container, and the compression mechanism rotates and slides through lubricating oil. A structure having a journal bearing portion having a moving rotating shaft and a bearing, and forming a right-handed spiral groove and a left-handed spiral groove on at least one of the outer circumference of the rotating shaft and the inner circumference of the bearing. be.

According to the above configuration, since the spiral groove is formed in the left-right direction on either the rotating shaft or the bearing, it is possible to promote the formation of an oil film between the rotating shaft and the bearing, and at the same time, Even if wear powder is produced in the As a result, seizure or abnormal wear can be suppressed or avoided in the sliding portion.

The present disclosure also includes a refrigeration system using the compressor. As a result, the operating efficiency and reliability of the compressor are improved, so that the quality of the refrigeration system can be improved.

The above object, other objects, features, and advantages of the present invention will be made clear from the following detailed description of preferred embodiments with reference to the accompanying drawings.

In the present invention, with the above configuration, seizure or abnormal wear due to lack of oil film or entrapment of abrasion powder between the rotating shaft and the bearing is suppressed or avoided, thereby improving operating efficiency and reliability. and a refrigerating apparatus using the same can be provided.

1 is a longitudinal sectional view of a rotary compressor according to Embodiment 1. FIG. FIG. 2 is an enlarged cross-sectional view of a compression mechanism portion of the rotary compressor shown in FIG. 3 is a plan view (process drawing) of a compression chamber showing a compression process of the rotary compressor shown in FIG. 1. FIG. FIG. 4 is an enlarged cross-sectional schematic diagram of an inner peripheral surface of an upper bearing, which is an example of a main part of the rotary compressor shown in FIG. FIG. 5 is a view of the inner peripheral surface of the upper bearing of the rotary compressor shown in FIG. 1 observed with a metallurgical microscope. FIG. 6 is a cross-sectional profile measurement result diagram of the inner peripheral surface of the upper bearing of the rotary compressor shown in FIG. 7A is an enlarged cross-sectional schematic diagram of an inner peripheral surface of another upper bearing of the rotary compressor shown in FIG. 1. FIG. 7B is an enlarged schematic sectional view of the inner peripheral surface of another upper bearing of the rotary compressor shown in FIG. 1. FIG. 7C is an enlarged schematic sectional view of the inner peripheral surface of another upper bearing of the rotary compressor shown in FIG. 1. FIG. 7D is an enlarged cross-sectional schematic diagram of the inner peripheral surface of another upper bearing of the rotary compressor shown in FIG. 1. FIG. FIG. 8 is a correlation diagram between the Sommerfeld number and the coefficient of friction in a journal friction test, comparing a representative example of Embodiment 1 and a conventional example. 9 is an enlarged schematic sectional view of the inner peripheral surface of the upper bearing of the rotary compressor according to Embodiment 2. FIG. 10 is an enlarged schematic sectional view of the inner peripheral surface of another upper bearing and the outer peripheral surface of the upper shaft of the rotary compressor shown in FIG. 9. FIG.

(Knowledge, etc. on which this disclosure is based)
At the time when the inventors came up with the present disclosure, as described in Patent Literature 1, a rotary compressor was developed by reducing the surface roughness of the outer peripheral surface of a rotating shaft or the inner peripheral surface of a bearing. An attempt was made to suppress or avoid an increase in frictional resistance or wear due to contact with microscopic projections on the surface.

However, in recent rotary compressors, the sliding area of the sliding parts has been narrowed in order to improve performance, and along with this, the surface pressure acting on the sliding surface of the rotating shaft tends to increase. In addition, efforts are being made to lower the viscosity of lubricating oils. Under such circumstances, mirror finishing, which reduces surface roughness, has a low ability to retain lubricating oil in the gap between the rotating shaft and the bearing. If the oil film is broken, the rotating shaft and the bearing will directly contact and slide, leading to an increase in frictional resistance or wear.

Also, the rotating shaft of the rotary compressor is supported by the upper bearing on the upper part of the cylinder and the lower bearing on the lower part. A radial load acting as a contact load is applied during the process of drawing and compressing the refrigerant, and the rotating shaft bends and rotates while tilting inside the upper and lower bearings. Therefore, especially near the lower end of the bearing, there is a high possibility that the gap between the rotating shaft and the bearing is extremely small or almost zero (contact).

As a result, as mentioned above, when mirror finishing is used to reduce the surface roughness, the lubricating oil does not form a sufficient oil film, especially at the lower end of the bearing. . Furthermore, there is also a problem that abrasion powder generated by solid contact or the like is caught in the gap between the rotating shaft and the bearing, and becomes a starting point of adhesive wear or abrasive wear.

The inventors found such a problem and came to constitute the subject of the present disclosure in order to solve it.

Therefore, in the present disclosure, when the surface pressure is increased or low-viscosity lubricating oil is used, the formation of an oil film in the gap between the rotating shaft and the bearing is promoted, or the discharge of abrasion powder is promoted from the gap between the rotating shaft and the bearing. Compressors and refrigerating equipment that maintain high performance and reliability over the long term by being able to suppress seizure or wear (or both seizure and wear) associated with direct contact sliding. offer.

Hereinafter, embodiments will be described in detail with reference to the drawings. However, more detailed description than necessary may be omitted. For example, detailed descriptions of well-known matters or redundant descriptions of substantially the same configurations may be omitted. This is to avoid the following description from becoming more redundant than necessary and to facilitate understanding by those skilled in the art.

It should be noted that the accompanying drawings and the following description are provided to allow those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

(Embodiment 1)
Embodiment 1 according to the present disclosure will be described below with reference to FIGS. 1 to 8. FIG.

[1-1. Constitution]
As shown in FIGS. 1 to 3, the rotary compressor includes a closed container 1, an electric mechanism section 2, a compression mechanism section 3, and the like. The electric mechanism portion 2 and the compression mechanism portion 3 are connected by a crankshaft 31 and housed in the sealed container 1 . An oil reservoir 6 is provided at the bottom of the sealed container 1 , and a discharge pipe 5 is provided at the top of the sealed container 1 .

The inside of the sealed container 1 is divided by the electric mechanism portion 2 into an upper container inner space 81 having the discharge pipe 5 and a lower container inner space 82 including the oil storage portion 6 and the compression mechanism portion 3 . 81 and 82 are connected by a plurality of refrigerant passages provided in the electric mechanism section 2 .

The electric mechanism section 2 is composed of a stator 22 arranged on the outside and a rotor 24 arranged on the inside. The rotor 24 is fixed and connected to the crankshaft 31 of the compression mechanism 3, and rotates the crankshaft 31 as the rotor 24 rotates. The compression mechanism portion 3 is connected to the intake pipe 4 via an accumulator 40 .

In addition, as shown in FIG. 2 or 3, the compression mechanism section 3 includes a cylinder 30, bearings 35, piston rollers 32, vanes 33, and the like. A suction chamber 49 and a compression chamber 39 are formed in the cylinder 30 by closing both end surfaces of the cylinder 30 . The bearing 35 consists of an upper bearing 35a and a lower bearing 35b. The piston roller 32 is fitted on a crankshaft 31c of a crankshaft 31 supported by a bearing 35 inside the cylinder 30 . The vane 33 partitions the inside of the cylinder 30 into a suction chamber 49 and a compression chamber 39 .

The crankshaft 31 is composed of a shaft 31a positioned upward in FIG. 1, a crankshaft 31c with an eccentric shaft center, and a lower shaft 31b positioned below (lower in FIG. 1). The axial centers of the upper shaft 31a and the lower shaft 31b are the same.

An oil hole 41 is provided in the axial portion of the crankshaft 31, an oil supply hole 42 is provided in the wall of the upper shaft 31a for the upper bearing 35a, and an oil supply hole 43 is provided in the wall of the lower shaft 31b for the lower bearing 35b. is provided. An oil supply hole 44 communicating with the oil hole 41 is provided in the wall portion of the crankshaft 31c of the crankshaft 31, and an oil groove 45 is formed in the outer peripheral portion.

On the other hand, the cylinder 30 has a suction port 46 for sucking gas into a suction chamber 49, and the upper bearing 35a has a discharge port 38 for discharging gas from a compression chamber 39 formed by turning from the suction chamber 49. (see FIG. 3) is opened.

The discharge port 38 is formed as a circular hole extending through the upper bearing 35a. The upper surface of the discharge port 38 is provided with a discharge valve (not shown) that is released when a pressure exceeding a predetermined level is received, and a valve stop (not shown) that regulates the maximum displacement of the valve. .

A muffler cover 37 is provided above the upper bearing 35a, and a space defined by the upper bearing 35a and the muffler cover 37 serves as a discharge space 52. The discharge space 52 communicates with the compression chamber 39 via the discharge port 38, and opens into the container inner space 82 below via a discharge port (not shown). A lubricating oil return passage 35c is provided near the outer periphery of the upper bearing 35a.

The refrigerant gas sucked from the suction pipe 4 is guided to the compression mechanism section 3 from the suction port 46 via the accumulator 40 . In order to prevent excessive liquid compression in the compression mechanism 3, the accumulator 40 selectively guides the refrigerant gas from among the liquid components to the suction port 46 when the refrigerant flowing from the suction pipe 4 is mixed. . The accumulator 40 has the suction pipe 4 connected to the upper part of the cylindrical case and the refrigerant gas outlet pipe connected to the lower part. One end of the refrigerant gas lead-out pipe is connected to the intake port 46, and the other end extends to the top of the internal space of the case.

In the compression mechanism section 3, the piston roller 32 is fitted to the crankshaft 31c and rotates eccentrically. The vane 33 reciprocates toward the outer periphery of the piston roller 32 with respect to the eccentric rotation of the piston roller 32 . The contact between the outer peripheral surface of the eccentrically rotating piston roller 32 and the inner peripheral surface of the cylinder 30 is maintained by the vane 33 . As a result, a suction chamber 49 that increases in volume and a compression chamber 39 that is partitioned from the suction port 46 and decreases in volume are formed in the cylinder 30 .

That is, the refrigerant gas is sucked from the suction pipe 4 as the suction chamber 49 expands in volume. As the volume of the compression chamber 39 is reduced, the compressed refrigerant gas is discharged from the discharge port 38 into the discharge space 52 . Refrigerant gas in the discharge space 52 is sent out from a discharge port (not shown) into the container internal space 82 below.

This refrigerant gas flows through the refrigerant passage 26 between the stator 22 and the rotor 24 of the electric mechanism section 2 and the rotor refrigerant passage 27 in the rotor 24 to the container inner space 81 above, and the discharge pipe 5 It is sent out of the sealed container 1 further.

The internal space of the sealed container 1 excluding the compression chamber 39 and the suction chamber 49 is a space in which the refrigerant gas that has been compressed to a high temperature and high pressure state stays, and the lubricating oil in the oil reservoir 6 is also in a high pressure state.

The crankshaft 31 draws lubricating oil from the oil reservoir 6 through the oil hole 41 and supplies it through the oil supply holes 43, 44, 42 to the lower bearing 35b, the suction chamber 49, the compression chamber 39, and the upper bearing 35a. The lubricating oil supplied to the suction chamber 49 and the compression chamber 39 passes through the discharge port 38 together with the compressed refrigerant gas and is discharged from the discharge space 52 through the discharge port into the container inner space 82 below. Similarly, the lubricating oil discharged from the upper end of the upper bearing 35a is also discharged into the container internal space 82 below.

Some of the lubricating oil discharged into the lower container space 82 adheres to the surface of the lower container inner space 82 and drops due to its own weight, and passes through the lubricating oil return passage 35c of the upper bearing 35a to reach the oil reservoir 6. back to Other lubricating oil passes through the rotor refrigerant passage 27 or the refrigerant passage 26 together with the refrigerant gas and reaches the container internal space 81 above.

In the container inner space 81 above, the lubricating oil collects in the upper part of the electric mechanism part 2 due to adhesion to the surface of the container inner space 81, the self weight of the lubricating oil, or the surface tension of the lubricating oil. It returns to the oil reservoir 6 via the inner space 82 and the lubricating oil return passage 35c.

The rotary compressor having the above configuration includes a plurality of journal bearings each composed of a rotating shaft and a bearing that supports the rotating shaft. Specifically, for example, in the present embodiment, a combination of the lower shaft 31b of the crankshaft 31 and the lower bearing 35b, or a combination of the upper shaft 31a and the upper bearing 35a, or the like may be used.

FIG. 4 is an enlarged cross-sectional schematic diagram of the inner peripheral surface of the upper bearing 35a of the rotary compressor. As shown in FIG. 4, in the present embodiment, a right-handed spiral groove 61 and a left-handed spiral groove 62 are formed on the inner peripheral surface of the upper bearing 35a.

Here, based on the vertical cross-sectional view of the rotary compressor shown in FIG. 1, hereinafter, left rotation is defined as left rotation and counterclockwise rotation is defined as right rotation as viewed from the oil reservoir 6 side. The spiral groove 62 formed so as to extend toward the electric mechanism portion 2 side when viewed from the oil storage section 6 side when rotated counterclockwise is referred to as a "left-handed spiral groove 62". The spiral groove 61 formed so as to extend toward the electric mechanism portion 2 is referred to as a "right-handed spiral groove 61".

The right-handed spiral groove 61 and the left-handed spiral groove 62 are honed with a rough grindstone and then honed with a finishing grindstone. As a result, convex portions of the surface roughness of these spiral grooves 61 and 62 are eliminated, and concave portions (groove portions) remain.

As shown in FIG. 4 and an enlarged view of part A in FIG. 4, the right-handed spiral groove 61 and the left-handed spiral groove 62 intersect to form a cross point 65 . As shown in FIG. 4, the angle formed in the rotation direction of the upper shaft 31a of the crankshaft 31 is defined as the cross angle. In this embodiment, the cross angle of the upper bearing 35a is substantially the same at 20° from the upper end to the lower end of the upper bearing 35a.

FIG. 5 is a metallurgical microscope photograph of the surface state of the inner circumference observed while tilting the upper bearing 35a, and FIG. 6 is a cross-sectional profile measurement in the direction of the arrow in FIG. This is the result.

As shown in FIGS. 4 and 5, a right-handed spiral groove 61 and a left-handed spiral groove 62 form a flat portion 63 and a groove portion 64 on the inner peripheral surface of the upper bearing 35a. Quantitative parameters of the flat portion 63 and the groove portion 64 can be obtained based on JIS B0671-2. The test method specified in JIS B0671-2 can be replaced by the national standards of each country or international standards.

In the present embodiment, the index of the flat portion 63 is indicated by the flat portion roughness Rpk. The flat portion roughness Rpk of the specific examples shown in FIGS. 5 and 6 was actually measured to be 0.1 to 0.2 μm. Similarly, the index of the groove portion 64 is indicated by the oil pool depth Rvk. The oil pool depth Rvk of the concrete example shown in FIGS. 5 and 6 was 1.0 to 2.0 μm by actual measurement.

In this way, the structure of the rotary compressor according to the present disclosure (either the outer circumference of the rotating shaft or the inner circumference of the bearing structure in which a right-handed spiral groove and a left-handed spiral groove are formed in the groove) can be easily recognized.

In addition, by adjusting the rotation speed and feed rate of the honing grindstone, and the pressing pressure on the inner peripheral surface, etc., the cross angle formed by the intersection of the right-handed spiral groove 61 and the left-handed spiral groove 62 and the roughness of the flat portion can be adjusted. It is possible to control the depth Rpk and the oil pool depth Rvk.

Note that the spiral grooves 61 and 62 are shown at regular intervals in the enlarged cross-sectional schematic view of the inner peripheral surface shown in FIG. However, in an actual honing process, as shown in FIG. 5, the spiral grooves 61 and 62 are not necessarily equidistant, and there are portions with so-called unequal intervals.

The technology of the present disclosure is not limited to the above description, and can also be applied to embodiments with modifications, replacements, additions, omissions, and the like. Therefore, hereinafter, examples of configurations of other embodiments will be described. 7A to 7D are enlarged cross-sectional views of the inner peripheral surface of an upper bearing 35a of a rotary compressor according to another embodiment.

In the embodiment shown in FIG. 7A, the groove spacing P1 in the axial direction of the upper bearing in the right-handed spiral groove 61 formed in the inner peripheral surface of the upper bearing 35a and the groove spacing in the axial direction of the upper bearing in the left-handed spiral groove 62 are P2 is different. Specifically, the groove interval P2 is set smaller than the groove interval P1.

7B, in the left-handed spiral groove 62 formed in the inner peripheral surface of the upper bearing 35a, the groove interval P22 on the lower side and the groove interval P21 on the upper side with respect to the axial direction of the upper bearing 35a are different. different. Specifically, the groove interval P22 is set smaller than the groove interval P1.

In the embodiment shown in FIG. 7C, in the left-handed spiral groove 62 formed in the inner peripheral surface of the upper bearing 35a, the groove interval P22 on the lower side and the groove interval P21 on the upper side with respect to the axial direction of the upper bearing 35a are different. In addition to the difference, in the right-handed spiral groove 61, the groove interval P12 on the lower side and the groove interval P11 on the upper side with respect to the axial direction of the upper bearing 35a are different. Specifically, the groove interval P22 is smaller than the groove interval P21, and the groove interval P12 is smaller than the groove interval P11.

In the embodiment shown in FIG. 7D, a right-handed spiral groove 61 and a left-handed spiral groove 62 are formed on the sliding surface of a bush bearing 67 inserted and fixed to the inner periphery of the upper bearing 35a by press fitting or shrink fitting. ing. A lubricating oil conveying groove, which will be described later, may be formed in the sliding surface of the bush bearing 67 .

A more specific configuration of the rotary compressor according to the present disclosure is not particularly limited, and various known configurations can be suitably used. For example, the rotary compressor may be placed horizontally, two piston rollers 32 may be provided, or the lower bearing 35b may be formed. Also, the type of compressor is not particularly limited. Although the rotary compressor has been described in the present embodiment, the technique of the present disclosure can also be applied to a known reciprocating compressor, scroll compressor, or the like.

[1-2. Actions and effects, etc.]
The operation and action of the rotary compressor according to the present embodiment configured as described above will be described below.

In this embodiment, as shown in FIG. 4, a right-handed spiral groove 61 and a left-handed spiral groove 62 are formed on the inner periphery of the upper bearing 35a. As a result, the lubricating oil that has flowed into the spiral grooves 61 and 62 joins and collides with each other at cross points 65 between the spiral grooves 61 and 62 . Therefore, the lubricating oil leaking from the cross point 65 seeps out to the flat portion 63 to form an oil film. As a result, scratches or wear due to direct contact between the shaft and the bearing can be suppressed satisfactorily.

Here, using the rotating shaft and bearings, a journal friction test was conducted with operating conditions (rotating speed, viscosity, sliding surface pressure) as parameters. A conventional example with a mirror-finished sliding surface was used for comparison. FIG. 8 is a correlation diagram between the Sommerfeld number and the coefficient of friction in a journal friction test. The Sommerfeld number is a dimensionless number obtained by dividing the value obtained by multiplying the rotational speed by the viscosity by the sliding surface pressure, and is often used as an index indicating the severity of lubrication.

　The lubrication state between the rotating shaft and the bearing can be divided into three areas according to the viscosity of the lubricating oil, the rotational speed, and the sliding surface pressure. FIG. 8 shows a hydrodynamic lubrication region (X), a mixed lubrication region (Y), and a boundary lubrication region (Z) assumed from the friction characteristic curve in the conventional example. In the hydrodynamic lubrication region (X), the lubricating oil is interposed between the rotating shaft and the bearing, lubricating them in a completely separated state. On the other hand, in the boundary lubrication region (Z), the lubricating oil film becomes extremely thin, and the interfacial chemical properties of the lubricating oil become important in the region where the friction phenomenon cannot be explained from the viscosity of the lubricating oil. In the mixed lubrication region (Y), both fluid lubrication and boundary lubrication occur.

In FIG. 8, a solid line indicates a representative example of the present embodiment, and a broken line indicates a typical conventional example. In the embodiment, a right-handed spiral groove 61 and a left-handed spiral groove 62 are provided on the inner periphery of the bearing, and a plateau surface having a flat portion 63 and a groove portion 64 is formed. As a result, the friction coefficient is remarkably reduced in the boundary lubrication region (Z) and the mixed lubrication region (Y) among the lubrication regions in the conventional example. By promoting the formation of an oil film between the rotating shaft and the bearing, contact sliding between the rotating shaft and the bearing can be alleviated and the coefficient of friction can be significantly reduced. and wear) can be better avoided. Even if it is applied to the journal bearing portion of the compressor, the state of formation of the oil film is similarly significantly improved, so that the performance and reliability of the compressor can be improved over a long period of time.

When the upper shaft 31a of the crankshaft 31 rotates counterclockwise as shown in FIG. 4, the left-handed spiral groove 62 causes the lubricating oil to flow upward from the oil reservoir 6 toward the electric mechanism 2 due to viscous resistance. responsible for the ability to transport Thereby, the lubricity of the sliding portion of the compression mechanism portion 3 can be further improved.

Contrary to the left-handed spiral groove 62, the right-handed spiral groove 61 has the ability to guide the lubricating oil to the lower side of the bearing (oil reservoir 6 side). When abrasion powder is generated at the lower end of the bearing due to uneven contact between the shaft and the bearing, the abrasion powder is carried by the viscous resistance of the lubricating oil and flows upwards from the bearing (from the oil storage section 6 to the electric mechanism section 2). ), but guided downward (on the oil reservoir 6 side) of the bearing through the right-handed spiral groove 61 . Therefore, abrasion powder is discharged out of the bearing. As a result, it is possible to prevent or suppress the occurrence of abrasive wear or adhesive wear originating from the entry of abrasion powder in the gap between the rotating shaft and the bearing.

Further, in the present embodiment, the right-handed spiral groove 61 and the left-handed spiral groove 62 are formed by honing. Therefore, as described above, the spiral grooves 61 and 62 are not necessarily equidistantly spaced, and some parts are found to be unequally spaced. It has been experimentally confirmed that even if the spiral grooves 61 and 62 have such unequal intervals, a similar oil film forming action or abrasion powder discharging action can be obtained. In addition, since it is a honing technology that is commonly used for drilling holes in bearings, it can be easily applied to processing lines. Therefore, the technology in the present disclosure is excellent in mass productivity.

In this embodiment, the spiral grooves 61 and 62 are formed on the inner periphery of the upper bearing 35a, but similar effects can be obtained by forming them on the outer periphery of the upper shaft 31a. By forming the spiral grooves 61 and 62 on either the inner circumference of the lower bearing 35b or the outer circumference of the lower shaft 31b, the performance and reliability of the lower shaft 31b and the lower bearing 35b can be improved.

In the present embodiment, the cross angle formed by the intersection of the right-handed spiral groove 61 and the left-handed spiral groove 62 with respect to the rotation direction of the rotating shaft is set to 20°. Not limited to angles. In the present disclosure, even if the cross angle is greater than 0° and 30° or less (0°<[cross angle]≦30°), similar effects can be obtained.

If the cross angle is 0°, each groove is not the spiral grooves 61 and 62 but an independent annular groove. Therefore, seepage of the lubricating oil due to merging of the lubricating oil is not obtained. Also, since the annular grooves do not connect with each other, no lubricating oil is conveyed.

On the other hand, if the cross angle is made larger than 30°, the amount of lubricating oil flowing out from the right-handed spiral groove 61 becomes excessive. Therefore, it has been experimentally confirmed that when the cross angle exceeds 30°, a sufficient effect of promoting the formation of the oil film on the flat portion 63 due to seepage of the lubricating oil is not obtained.

In this embodiment, as described above, the flat portion 63 has a flat portion roughness Rpk of 0.1 to 0.2 μm, and the groove portion 64 has an oil pool depth Rvk of 1.0 to 2.0 μm. 0 μm. However, the disclosure is not so limited.

At the outer circumference of the rotating shaft where the right-handed spiral groove 61 and the left-handed spiral groove 62 are formed, or the inner peripheral surface of the bearing, the oil reservoir depth Rvk is 0.5 μm or more and 3 μm or less (0.5 μm≦Rvk≦3 μm). In addition, if the flat portion roughness Rpk is 0.01 μm or more and 0.5 μm or less (0.01 μm≦Rpk≦0.5 μm), similar effects can be obtained. Further, the upper limit value or lower limit value of each range of the oil pool depth Rvk or the flat portion roughness Rpk can be appropriately combined. For example, depending on various conditions, the oil pool depth Rvk can be in the range of 1.0-3.0 μm, and the flat portion roughness Rpk can be in the range of 0.1-0.5 μm.

In the spiral grooves 61 and 62, if the oil pool depth Rvk is less than 0.5 μm, the surface properties are substantially the same as those of the mirror surface, and the lubricating oil holding capacity is insufficient. On the other hand, if the oil pool depth Rvk is greater than 3 μm, even if the lubricating oil joins the spiral grooves 61 and 62 at the cross point 65, it will not sufficiently seep out to the flat portion 63, and the oil film will not be formed. It has been confirmed experimentally that this is sufficient.

Also, even if the flat portion roughness Rpk is made smaller than 0.01 μm, the effect can be obtained, but the processing time per part becomes longer and the wear of the processing tool becomes faster. Therefore, from the viewpoint of mass productivity and manufacturing cost of the compressor, it is not desirable for the flat portion roughness Rpk to be less than 0.01 μm. On the other hand, if the flat portion roughness Rpk is larger than 0.5 μm, the convex portion of the flat portion 63 may become the starting point of oil film breakage if the gap between the shaft and the bearing is too small.

In the embodiment shown in FIG. 7A, the groove interval P2 in the left-handed spiral groove 62 in the axial direction of the upper bearing is smaller than the groove interval P1 in the right-handed spiral groove 61 in the axial direction of the upper bearing. . As a result, when the rotation direction of the upper shaft 31a is counterclockwise as shown in the drawing, the lubricating oil retained in the upper shaft 31a and the upper bearing 35a is reduced by reducing the groove interval P2 of the left-handed spiral groove 62. quantity increases. Furthermore, since the area of the flat portion 63 is reduced when the groove interval P2 is reduced, the lubricating oil leaking from the cross point 65 easily forms an oil film over the entire flat portion 63 .

It should be noted that increasing the groove interval P2 of the left-handed spiral groove 62 increases the conveying speed of the lubricating oil. On the other hand, when the groove interval P1 of the right-handed spiral groove 61 is increased, an effect is obtained in which abrasion powder generated in the bearing is easily discharged. It is desirable to select appropriate groove intervals for the right-handed spiral groove 61 and/or the left-handed spiral groove 62 (or both) depending on various conditions such as the operating conditions of the compressor or the specifications of the journal bearing.

In the embodiment shown in FIG. 7B or FIG. 7C, the groove spacing on the oil storage section 6 side (lower side) and the groove spacing on the electric mechanism section 2 side (upper side) with respect to the axial direction of the upper bearing 35a intervals are different.

For example, in a situation where the upper shaft 31a rotates and slides while tilting in the upper bearing 35a, the gap between the upper shaft 31a and the upper bearing 35a in the vicinity of the lower end of the upper bearing 35a tends to become too small. In this case, the interval between grooves near the lower end of the upper bearing 35a should be reduced.

As a result, the amount of lubricating oil held between the upper shaft 31a and the upper bearing 35a can be increased. Moreover, since the area of the flat portion 63 can be reduced by reducing the groove interval, the lubricating state in the vicinity of this portion can be remarkably improved.

On the other hand, as described above, in a situation where the upper shaft 31a rotates and slides while tilting in the upper bearing 35a, there is a sufficient gap between the upper shaft 31a and the upper bearing 35a near the axial center of the upper bearing 35a. easy to secure. Therefore, it is not necessary to reduce the groove interval near the center. In this manner, the groove spacing in the axial direction of the spiral grooves 61 and 62 can be changed according to the lubrication state.

That is, at least one of the right-handed spiral groove 61 and the left-handed spiral groove 62 has a configuration in which the groove spacing in the axial direction of the rotating shaft or the bearing is uneven from the lower end to the upper end of the inner peripheral surface of the bearing. can be adopted.

Note that in the embodiment shown in FIG. 7D, a right-handed spiral groove 61 and a left-handed spiral groove 62 are formed on the sliding surface of a bush bearing 67 inserted into the inner circumference of the upper bearing 35a. The bushing bearing 67 is generally made of cast iron, bronze-based material, metal-based material such as aluminum alloy-based material, or known resin-based material, composite material of resin and metal, alloy, or graphite impregnated with resin. Since it is formed using a carbon material or the like, it has very high self-wear resistance.

Here, the rotary compressor is configured such that lubricating oil is lifted from the oil reservoir 6 toward the electric mechanism section 2 by energizing the electric mechanism section 2 and rotating the crankshaft 31 . Therefore, there is a possibility that sufficient lubricating oil may not be secured in the gap between the upper shaft 31a and the upper bearing 35a immediately after startup.

However, by forming a bushing bearing 67 with high wear resistance as shown in FIG. 7D, it is possible to avoid wear when lubricating oil is excessive or insufficient, such as immediately after startup. In addition, during operation, the right-handed spiral groove 61 and the left-handed spiral groove 62 exhibit favorable effects of forming an oil film and discharging abrasion powder. As a result, it is possible to obtain a compressor that achieves excellent performance and reliability over a long period of time both during start-up and during operation.

As described above, the compressor according to the present embodiment includes the electric mechanism portion, the compression mechanism portion, and the oil storage portion in the closed container, and the compression mechanism portion rotates and slides through the lubricating oil. It has a journal bearing portion having a shaft and a bearing, and has a right-handed spiral groove and a left-handed spiral groove formed on at least one of the outer circumference of the rotating shaft and the inner circumference of the bearing.

As a result, it is possible to promote the formation of an oil film in the gap between the rotating shaft and the bearing, and promote the discharge of abrasion powder from the gap between the rotating shaft and the bearing. Therefore, seizure or wear (or both seizure and wear) associated with direct contact sliding can be suppressed. As a result, it is possible to improve the performance and reliability of the compressor.

In the compressor having the above configuration, the cross angle formed by the intersection of the right-handed spiral groove and the left-handed spiral groove with respect to the rotation direction of the rotating shaft is set to be greater than 0° and 30° or less. may

In the compressor having the above configuration, the depth of the oil pool on the inner peripheral surface of the bearing in which the right-handed spiral groove and the left-handed spiral groove are formed, or the outer periphery of the rotating shaft, which is obtained based on JIS B0671-2 Rvk may be 0.5 μm or more and 3 μm or less, and flat portion roughness Rpk may be 0.01 μm or more and 0.5 μm or less.

Further, in the compressor having the above configuration, the groove interval of the right-handed spiral groove in the axial direction of the rotating shaft or the bearing is different from the groove interval of the left-handed spiral groove in the axial direction of the rotating shaft or the bearing. There may be.

Further, in the compressor having the above configuration, at least one of the right-handed spiral groove and the left-handed spiral groove has an uneven groove interval in the axial direction of the rotating shaft or the bearing from the lower end to the upper end of the inner peripheral surface of the bearing. may be a configuration.

Further, in the compressor having the above configuration, a bush bearing may be provided on the inner periphery of the bearing, and a right-handed spiral groove and a left-handed spiral groove may be formed on the sliding surface of the bush bearing.

If such a compressor is installed in a refrigerating apparatus, the refrigerating apparatus can be made highly efficient and even more reliable. Note that the specific configuration of the refrigeration apparatus according to the present disclosure is not limited as long as it includes a known refrigerant circuit (refrigeration cycle) including the compressor according to the present disclosure. The specific configuration of the refrigerating device is also not particularly limited, and any known refrigerating device such as an air conditioner, a water heater, or a refrigerator may be used.

(Embodiment 2)
Embodiment 2 according to the present disclosure will be described below with reference to FIG.

[2-1. Constitution]
The same configurations as those described in the first embodiment, that is, the same configurations as those described with reference to FIGS.

FIG. 9 is an enlarged cross-sectional schematic diagram of the inner peripheral surface of the upper bearing 35a of the rotary compressor. In this embodiment, a right-handed spiral groove 61, a left-handed spiral groove 62, and a lubricating oil conveying groove 66a are formed on the inner peripheral surface of the upper bearing 35a.

As described in the first embodiment, the index of the flat portion 63 is indicated by the flat portion roughness Rpk, and the index of the groove portion 64 is indicated by the oil pool depth Rvk. In a specific example of the second embodiment, the flat portion roughness Rpk of the flat portion 63 is actually measured to be 0.1 to 0.2 μm, and the oil pool depth Rvk of the groove portion 64 is also measured by actual measurement. It was 1.0 to 2.0 μm.

The lubricating oil conveying groove 66a has a groove depth and a groove width larger than those of the right-handed spiral groove 61 and the left-handed spiral groove 62, and is arranged along the rotating shaft in the direction in which viscous resistance acts on the rotating direction of the rotating shaft. It is formed so as to incline with respect to.

Assuming that the groove depth of the lubricating oil conveying groove 66a is d1, and the groove depth of the right-handed spiral groove 61 or the left-handed spiral groove 62 is d2, the depth of the spiral grooves 61 and 62 is greater than the groove depth d1 of the lubricating oil conveying groove 66a. The groove depth d2 may be within the range of 4.0×10 ^-4 to 2.0×10 ^-3 . In other words, the groove depth ratio d2:d1=4.0×10 ⁻⁴ to 2.0×10 ⁻³ :1.

Assuming that the groove width of the lubricating oil conveying groove 66a is w1, and the groove width of the right-handed spiral groove 61 or the left-handed spiral groove 62 is w2, the spiral grooves 61 and 62 have a groove width w1 of the lubricating oil conveying groove 66a. The width may be within the range of 6.0×10 ^-3 to 1.0×10 ^-2 . In other words, the groove width ratio w2:w1 should be 6.0×10 ⁻³ to 1.0×10 ⁻² :1.

[2-2. Actions and effects, etc.]
The operation and action of the rotary compressor constructed as described above will be described below. It should be noted that redundant description of the configuration that is substantially the same as that of the rotary compressor described in the first embodiment is basically omitted.

In the present embodiment, the lubricating oil conveying groove 66a having a groove width and a groove depth larger than those of the left-handed spiral groove 62 is formed in a direction in which viscous resistance acts with respect to the rotation direction of the rotating shaft. Therefore, the amount of lubricating oil conveyed upward from the oil storage section 6 side toward the electric mechanism section 2 side can be significantly increased. As a result, the amount of lubricating oil flowing into the left-handed spiral groove 62 and the right-handed spiral groove 61 from the lubricating oil conveying groove 66a can be increased, so that the amount of lubricating oil seeping from the cross point 65 to the flat portion 63 is increased. can also be increased. In addition, the discharge of abrasion powder from the right-handed spiral groove 61 can also be promoted. Furthermore, by increasing the amount of lubricating oil flowing into the gap between the upper shaft 31a and the upper bearing 35a, it is possible to effectively suppress heat generation due to sliding, thereby contributing to avoiding progress of wear or promoting formation of an oil film.

Therefore, in this embodiment, in addition to the action of forming an oil film between the upper shaft 31a and the upper bearing 35a and the action of discharging abrasion powder, the action of cooling the sliding portion by the lubricating oil is realized. be able to. This cooling action suppresses seizure or wear (or both seizure and wear) associated with direct contact sliding, and improves the performance and reliability of the compressor.

Further, in the present embodiment, the lubricating oil conveying groove 66a is formed on the inner circumference of the upper bearing 35a, but the present disclosure is not limited to this. For example, the lubricating oil conveying groove 66a may be formed separately on a peripheral surface different from the spiral grooves 61 and 62 .

For example, as shown in FIG. 10, the left-handed spiral groove 62 and the right-handed spiral groove 61 may be formed on the inner peripheral surface side of the upper bearing 35a, and the lubricating oil conveying groove 66b may be formed on the outer peripheral surface side of the upper shaft 31a. good. Alternatively, vice versa, that is, the spiral grooves 61 and 62 may be formed on the outer peripheral surface side of the upper shaft 31a and the lubricating oil conveying groove 66b may be formed on the inner peripheral surface side of the upper bearing 35a. Thus, even if the lubricating oil conveying groove 66a and the spiral grooves 61 and 62 are separately formed, the same effect as described above can be obtained.

Furthermore, the left-handed spiral groove 62 and the right-handed spiral groove 61 may also be collectively provided on either the inner peripheral surface side of the upper bearing 35a or the outer peripheral surface side of the upper shaft 31a. The same effect can be obtained even if it is separately formed on the surface side or the outer peripheral surface side of the upper shaft 31a.

Even if the right-handed spiral groove 61, the left-handed spiral groove 62, the lubricating oil conveying groove 66a, or the lubricating oil conveying groove 66b are formed on the inner circumference of the lower bearing 35b or the outer circumference of the lower shaft 31b, The performance and reliability of the lower bearing 35b can be improved.

Further, in the present embodiment, when the groove depth of the lubricating oil conveying groove 66a is d1 and the groove depth of the right-handed spiral groove 61 and the left-handed spiral groove 62 is d2, as described above, the groove depth ratio d2 :d1=4.0×10 ⁻⁴ to 2.0×10 ⁻³ :1, but the present disclosure is not limited thereto. For example, d2:d1 may be in the range of 2.0×10 ^-4 to 2.0×10 ^-2 . Similar effects can be obtained even within this range. Moreover, the upper limit value or the lower limit value of each range of the groove depth ratio can be appropriately combined. For example, d2:d1 can be in the range of 4.0×10 ⁻⁴ to 2.0×10 ⁻² depending on various conditions.

Alternatively, in the present embodiment, if the groove width of the right-handed spiral groove 61 or the left-handed spiral groove 62 is w2, the groove width ratio w2:w1=6.0×10 ⁻³ to 1.0×10 as described above. ^-2 :1, but the present disclosure is not limited to this. For example, w2:w1=3.0×10 ⁻³ to 2.0×10 ⁻² may be set. Similar effects can be obtained even within this range. Also, the upper limit value or lower limit value of each range of the groove width ratio can be appropriately combined in the same manner as the groove depth ratio.

As described above, the compressor according to the present embodiment includes the electric mechanism portion, the compression mechanism portion, and the oil storage portion in the closed container, and the compression mechanism portion rotates and slides through the lubricating oil. a journal bearing portion having a shaft and a bearing, forming a right-handed spiral groove and a left-handed spiral groove on at least one of the outer circumference of the rotating shaft and the inner circumference of the bearing; A configuration in which lubricating oil conveying grooves are formed on either the outer circumference of the rotating shaft or the inner circumference of the bearing may be used.

As a result, even when the surface pressure increases or low-viscosity lubricating oil is used, an oil film is formed in the gap between the rotating shaft and the bearing, or wear powder is discharged from the gap between the rotating shaft and the bearing. In addition, the cooling effect of the lubricating oil on the sliding portion can also be promoted. This suppresses seizure or wear (or both seizure and wear) that accompanies direct contact sliding, and as a result, it is possible to improve the performance and reliability of the compressor.

In the compressor configured as described above, the lubricating oil conveying groove has a depth and width greater than those of the right-handed spiral groove and the left-handed spiral groove, and is formed in a direction in which viscous resistance acts with respect to the rotation direction of the rotating shaft. configuration may be used.

If such a compressor is installed in a refrigerating apparatus, the refrigerating apparatus can be made highly efficient and even more reliable.

In addition, as described above, the compressor according to the present disclosure can improve the oil film formation condition in the journal bearing portion and effectively suppress seizure or wear of the sliding portion, and therefore has high reliability over a long period of time. In addition, the compressor according to the present disclosure has improved reliability and efficiency, and is useful for refrigerating cycle devices such as freezer-refrigerators, hot water heaters, air conditioners, water heaters, and refrigerators. In addition, the compressor according to the present disclosure is not only applicable to the refrigerating apparatus illustrated in the present embodiment, but can also be used in a car engine or the like to obtain the same effect, and the refrigerant can be used as a working medium. The same effect can be obtained even if it is applied to other compressors that do not

From the above description, many modifications and other embodiments of the invention will be apparent to those skilled in the art. Accordingly, the above description is to be construed as illustrative only and is provided for the purpose of teaching those skilled in the art the best mode of carrying out the invention. Substantial details of construction and/or function may be changed without departing from the spirit of the invention.

The present invention can be widely and suitably used in, for example, the field of compressors used in refrigeration systems, and can also be suitably used in the field of other compressors that do not use refrigerant as a working medium.

1: Closed container 2: Electric mechanism part 3: Compression mechanism part 6: Oil storage part 31: Rotating shaft 31: Crankshaft 31a: Upper shaft 31b: Lower shaft 35: Bearing 35a: Upper bearing 35b: Lower bearing 61: Right-handed spiral Grooves 62: Left-handed spiral grooves P1, P11, P12: Groove intervals (of right-handed spiral grooves) P2, P21, P22: Groove intervals (of left-handed spiral grooves) 66a, 66b: Lubricating oil conveying grooves 67: Bush bearing

Claims (9)

A motorized mechanism, a compression mechanism, and an oil reservoir are provided in a sealed container,
The compression mechanism section has a journal bearing section having a rotating shaft and a bearing that rotate and slide via lubricating oil,
A right-handed spiral groove and a left-handed spiral groove are formed on at least one of the outer circumference of the rotating shaft and the inner circumference of the bearing,
compressor. With respect to the rotation direction of the rotating shaft,
The cross angle formed by the intersection of the right-handed spiral groove and the left-handed spiral groove is set to be greater than 0° and 30° or less,
A compressor according to claim 1 . Obtained based on JIS B0671-2,
An oil reservoir depth Rvk of the inner peripheral surface of the bearing in which the right-handed spiral groove and the left-handed spiral groove are formed, or the outer periphery of the rotating shaft is 0.5 μm or more and 3 μm or less,
The flat portion roughness Rpk is 0.01 μm or more and 0.5 μm or less,
A compressor according to claim 1 or 2. A groove interval of the right-handed spiral groove in the axial direction of the rotating shaft or the bearing and a groove interval of the left-handed spiral groove in the axial direction of the rotating shaft or the bearing are different from each other.
A compressor according to any one of claims 1 to 3. In at least one of the right-handed spiral groove and the left-handed spiral groove, the groove spacing in the axial direction of the rotating shaft or the bearing is uneven from the lower end to the upper end of the inner peripheral surface of the bearing.
A compressor according to any one of claims 1 to 4. A bush bearing is provided on the inner circumference of the bearing, and the right-handed spiral groove and the left-handed spiral groove are formed on the sliding surface of the bush bearing,
A compressor according to any one of claims 1 to 5. At least one of the outer circumference of the rotating shaft and the inner circumference of the bearing is formed with a lubricating oil conveying groove,
A compressor according to any one of claims 1 to 6. The lubricating oil conveying groove has a greater depth and width than the right-handed spiral groove and the left-handed spiral groove,
formed in a direction in which viscous resistance acts with respect to the rotation direction of the rotating shaft,
A compressor according to claim 7 . A refrigeration system using the compressor according to any one of claims 1 to 8.

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