JP3977223B2 - Hermetic compressor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hermetic compressor used in a refrigerator, an air conditioner, a freezer / refrigerator, and the like.
[0002]
[Prior art]
In recent years, for hermetic compressors used in refrigeration apparatuses such as household refrigerator-freezers, reduction of power consumption and noise reduction have been strongly desired. Under such circumstances, the lowering of the viscosity of the lubricating oil and the lowering of the rotation speed of the compressor driven by the inverter (for example, about 1200 r / min in the case of a household refrigerator) have been advanced.
[0003]
On the other hand, it has become a premise to deal with hydrocarbon-based refrigerants and the like, which are natural refrigerants with low global warming coefficients, such as R134a and R600a, which have zero ozone depletion coefficient.
[0004]
In addition, the double-supported bearing method that holds the shaft at two or more places, which has been adopted from the past, is effective as an elemental technology for reducing sliding loss and reducing vibration and noise during operation.
[0005]
As a conventional hermetic compressor, there is one in which a separate sub-bearing is fixed to the upper portion of a compression portion with a screw (for example, see Patent Document 1).
[0006]
Hereinafter, the above-described conventional hermetic compressor will be described with reference to the drawings.
[0007]
FIG. 6 is a longitudinal sectional view of a conventional hermetic compressor. FIG. 7 is a top view of the main part of the conventional hermetic compressor with the upper container removed.
[0008]
6 and 7, the sealed container inner space 2 surrounded by the sealed container 1 is driven by the electric element 5 including the stator 3 and the rotor 4 having the winding portion 3 a and the electric element 5. The compression element 6 is accommodated. Lubricating oil 8 is stored in the sealed container 1.
[0009]
The shaft 10 includes a main shaft portion 11 in which the rotor 5 is press-fitted and fixed, an eccentric portion 12 formed eccentrically with respect to the main shaft portion 11, and a sub shaft portion 13 provided coaxially with the main shaft portion 11.
[0010]
The cylinder block 15 has a substantially cylindrical compression chamber 16 and a main bearing 17 that supports the main shaft portion 11, and a sub bearing 19 that supports the sub shaft portion 13 is fixed upward by three screws 20. The piston 19 is inserted into the compression chamber 16 of the cylinder block 15 so as to be slidable back and forth, and is connected to the eccentric portion 12 by a connecting means 21 and a piston pin 22.
[0011]
The operation of the hermetic compressor configured as described above will be described below.
[0012]
The rotor 4 of the electric element 5 rotates the shaft 10, and the rotational movement of the eccentric portion 12 is transmitted to the piston 19 via the connecting means 21, so that the piston 19 reciprocates in the compression chamber 16. As a result, the refrigerant gas is sucked and compressed into the compression chamber 16 from a cooling system (not shown) and then discharged again to the cooling system.
[0013]
Here, the mechanism for reducing the sliding loss of the double-end bearing will be described.
[0014]
During the operation of the compressor, the compression load of the piston 19 is transmitted to the eccentric portion 12 through the connecting means 21. Here, since the both-end bearing type receives the load at both the upper and lower bearings around the eccentric portion 12 (the action point) where the compression load from the piston 19 is applied, a substantially equal load is distributed to the bearings at the upper and lower sides. In addition, since the contact per surface is different from the cantilever bearing type in which the inner periphery is twisted, the load distribution of the sliding portion of the shaft 10 becomes uniform, the surface pressure is lowered, and the sliding length is shorter than that of the cantilever type. be able to. As a result, the sliding loss is reduced and the compressor can be improved in efficiency.
[0015]
[Patent Document 1]
JP-A-61-1118571 [0016]
[Problems to be solved by the invention]
However, in the above conventional configuration, the main bearing 17 and the cylinder block 15 have an integral structure, so that a material different from that of the cylinder block 15 cannot be used for the main bearing 17, so that higher energy efficiency can be obtained. There was a possibility that the friction coefficient could not be lowered and the sliding loss could not be reduced.
[0017]
In the conventional configuration, when the auxiliary bearing 18 is made of a material having a linear expansion coefficient different from that of the cylinder block 15, the axis of the auxiliary bearing 18 moves away from the axis of the main bearing 17 due to the temperature rise during operation. As a result, the load is not evenly distributed, the sliding loss does not decrease, and there is a possibility that sliding loss due to metal contact may occur.
[0018]
Further, in the above-described conventional configuration, since the fixing is performed only with the three screws 20, the shaft center of the auxiliary bearing 18 does not coincide with the shaft center of the main bearing 17, the load is not evenly distributed, and the sliding loss is not reduced. There was a possibility.
[0019]
Further, in the above conventional configuration, when the sub-bearing 18 is fixed to the cylinder block 15 when the compression element 6 is assembled, the shaft 10 must be rotated while the shaft 10 is rotated. The efficiency of was bad.
[0020]
Further, in the above-described conventional configuration, when the auxiliary bearing 18 is fixed to the cylinder block 15, there may be a variation in energy efficiency due to a variation during assembly.
[0021]
SUMMARY OF THE INVENTION The present invention solves the above-described conventional problems, and an object thereof is to provide a hermetic compressor having high energy efficiency and good assemblability.
[0022]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided a shaft having an eccentric shaft portion, a sub-shaft portion and a main shaft portion that are coaxially provided above and below the eccentric shaft portion, and a substantially cylindrical compression chamber. A cylinder block provided; a sub-bearing formed integrally with the cylinder block and supporting the countershaft portion; and a main bearing made of an aluminum material fixed to the cylinder block and supporting the main shaft portion; A flange extending in the radial direction of the main shaft of the main bearing is provided with a first guide portion having a diameter sharing the shaft center with the main bearing, and the cylinder block has a diameter sharing the shaft center with the auxiliary bearing. Two guide portions are provided, and the first guide portion is fitted to the second guide portion.
[0023]
In the invention described in claim 1 with the above configuration, the first guide portion and the second guide portion are fitted to limit the degree of freedom, so that the axis of the auxiliary bearing substantially coincides with the axis of the main bearing. The load is evenly distributed and the sliding loss is reduced. Also, aluminum material with a low coefficient of friction is used for the main bearing, and the main bearing has a separate structure from the cylinder block, so a material different from the cylinder block can be used for the main bearing. It has the effect of reducing the friction coefficient and reducing the sliding loss. Also, when the temperature rises during operation, the main bearing expands evenly in the radial direction around the shaft center, so that the temperature increase during operation prevents the auxiliary bearing shaft from deviating from the main bearing shaft center, and evenly. The load is distributed, the sliding loss is reduced, and the sliding loss due to the metal contact is not generated.
[0024]
According to a second aspect of the present invention, in addition to the first aspect of the invention, the inner diameter surface of the first guide portion and the outer diameter surface of the second guide portion are adjacent to each other, In addition to the operation of the present invention, it is not necessary to perform the operation of taking out the axis while rotating the shaft, so that the assembling efficiency is improved. Further, since the inner diameter surface of the first guide portion and the outer diameter surface of the second guide portion are separated during operation, it has the effect of reducing thermal deformation of the sliding portion of the main bearing during operation.
[0025]
The invention according to claim 3 is the invention according to claim 1, wherein the outer diameter surface of the first guide portion and the inner diameter surface of the second guide portion are further adjacent to each other. In addition to the operation of the present invention, it is not necessary to perform the operation of taking out the axis while rotating the shaft, so that the assembling efficiency is improved.
[0026]
The invention according to claim 4 is the invention according to claim 2, further comprising a groove provided on the inner peripheral side of the first guide portion in the main bearing and sharing a shaft center with the main bearing. In addition to the action of the invention of claim 2, the deformation is absorbed in the vicinity of the groove in the main bearing, particularly in the vicinity of being fixed, so that the thermal deformation of the sliding portion in the main bearing during operation is further reduced. Has an effect.
[0027]
The invention according to claim 5 is the invention according to claim 3, further comprising a groove provided on the inner peripheral side of the first guide portion in the main bearing and sharing a shaft center with the main bearing. In addition to the operation of the third aspect of the invention, since the deformation is absorbed around the entire circumference of the groove in the main bearing, it has the effect of reducing the thermal deformation of the sliding portion in the main bearing during operation.
[0028]
The invention according to claim 6 is the invention according to claim 2, wherein the first guide portion is lightly press-fitted into the second guide portion. In addition, the flange absorbs slight deformation caused by the outward radial force applied to the first guide part by light press-fitting, and the shaft center is adjusted with the processing accuracy of the first guide part and the second guide part. Therefore, the shaft center of the auxiliary bearing coincides with the shaft center of the main bearing with high accuracy, and the load is evenly distributed and the sliding loss is reduced. Further, since the gap between the first guide portion and the second guide portion, which is a variation factor, is eliminated, it has an effect of suppressing the occurrence of variations in energy efficiency due to variations during assembly.
[0029]
The invention according to claim 7 is the invention according to claim 3, wherein the first guide portion is lightly press-fitted into the second guide portion. In addition, the flange absorbs the slight deformation caused by the inward radial force applied to the first guide part by light press-fitting, and the shaft center is adjusted by the processing accuracy of the first guide part and the second guide part. Therefore, the shaft center of the auxiliary bearing coincides with the shaft center of the main bearing with high accuracy, and the load is evenly distributed and the sliding loss is reduced. Further, since the gap between the first guide portion and the second guide portion, which is a variation factor, is eliminated, it has an effect of suppressing the occurrence of variations in energy efficiency due to variations during assembly.
[0030]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of a compressor according to the present invention will be described below with reference to the drawings.
[0031]
(Embodiment 1)
1 is a longitudinal sectional view of a hermetic compressor according to Embodiment 1 of the present invention.
[0032]
As shown in FIG. 1, the sealed container 101 accommodates an electric element 104 including a stator 102 and a rotor 103 having a winding portion 102 a and a compression element 105 driven by the electric element 104.
[0033]
The compression element 105 includes, for example, an iron-based casting including a shaft 109 having a sub-shaft portion 107 and a main shaft portion 108 that are coaxially provided vertically with an eccentric shaft portion 106 interposed therebetween, and a substantially cylindrical compression chamber 110. A cylinder block 111 made of a material, a piston 112 reciprocating in the compression chamber 110, a connecting rod functioning as a connecting means 113 for connecting the piston 112 and the eccentric shaft portion 106, and the cylinder block 111 are formed integrally with the countershaft. A secondary bearing 114 that pivotally supports the portion 107 and a main bearing 115 that is fixed to the cylinder block 111 and pivotally supports the main shaft portion 108 are provided.
[0034]
For fixing the main bearing 115 to the cylinder block 111, for example, a screw, a rivet or the like can be used. The flange 116 of the main bearing 115 is provided with a first guide portion 117 having a diameter sharing the axis with the main bearing 115, and the cylinder block 111 has a second guide portion 118 having a diameter sharing the axis with the auxiliary bearing 114. And the first guide part 117 is fitted to the second guide part 118.
[0035]
For example, the first guide portion 117 has a circular shape or the like, and can be easily shared with the main bearing 115 by being processed simultaneously with the machining of the main bearing 115 by the rotating machine.
[0036]
For example, the second guide part 118 has a circular shape or the like, and can be easily shared with the auxiliary shaft part 107 by machining simultaneously with the machining of the auxiliary shaft part 107 by the rotating machine.
[0037]
As a result, the first guide portion 117 and the second guide portion 118 are fitted to limit the degree of freedom, so that the shaft center of the auxiliary bearing 114 substantially coincides with the shaft center of the main bearing 115 and the load is evenly distributed. The sliding loss can be reduced. In addition, since an aluminum material having a low friction coefficient is used for the main bearing 115 and the main bearing 115 is separated from the cylinder block 111, a material different from the cylinder block 111 can be used for the main bearing 115. In order to obtain efficiency, the friction coefficient can be lowered and the sliding loss can be reduced. Further, when the temperature rises during operation, the main bearing 115 expands evenly in the radial direction around the shaft center, so that the shaft center of the auxiliary bearing 114 deviates from the axis of the main bearing 115 due to the temperature rise during operation. The load is evenly distributed, the sliding loss is reduced, and the sliding loss due to the metal contact can be prevented.
[0038]
(Embodiment 2)
FIG. 2 is a cross-sectional view of the main part in the vicinity of the fitting portion between the cylinder block and the main bearing in the hermetic compressor according to the second embodiment.
[0039]
As shown in FIG. 2, the present embodiment further includes an inner diameter surface 119 of the first guide portion 117 and an outer diameter surface 120 of the second guide portion 118 in addition to the hermetic compressor according to the first embodiment. Are adjacent. The first guide portion 117 has, for example, a ring shape formed so as to protrude toward the cylinder block 111 on the outer periphery of the flange 116. The second guide portion 118 extends in a cylindrical shape from the cylinder block 111 toward the main bearing 115, for example.
[0040]
As a result, it is not necessary to take out the shaft center while rotating the shaft 108, so that the assembly efficiency can be improved. Further, since the inner diameter surface 119 of the first guide portion 117 and the outer diameter surface 120 of the second guide portion 118 are separated during operation, thermal deformation of the sliding portion of the main bearing 115 during operation is reduced. Can do.
[0041]
In the present embodiment, the first guide portion 117 is fitted to the second guide portion 118, but the first guide portion 117 may be lightly press-fitted into the second guide portion 118.
[0042]
Since the first guide portion 117 is lightly press-fitted into the second guide portion 118, the flange 116 absorbs a slight deformation caused by an outward radial force applied to the first guide portion 117 by light press-fitting. In addition, since the shaft center is determined by the processing accuracy of the first guide portion 117 and the second guide portion 118, the shaft center of the auxiliary bearing 114 coincides with the shaft center of the main bearing 115 with high accuracy, and the load is evenly distributed. As a result, the effect of reducing sliding loss can be obtained. In addition, since the gap between the first guide portion 117 and the second guide portion 118 that causes variation is eliminated, an effect of suppressing the occurrence of variation in energy efficiency due to variation during assembly can be obtained.
[0043]
(Embodiment 3)
FIG. 3 is a cross-sectional view of the main part in the vicinity of the fitting portion between the cylinder block and the main bearing in the hermetic compressor according to the third embodiment.
[0044]
As shown in FIG. 3, this embodiment further includes an outer diameter surface 121 of the first guide portion 117, an inner diameter surface 122 of the second guide portion 118, and the hermetic compressor according to the first embodiment. Are adjacent to each other.
[0045]
The first guide portion 117 is obtained by, for example, processing the outer periphery of the flange 116 by polishing, and the second guide portion 118 is, for example, extended from the cylinder block 111 toward the main bearing 115 in a ring shape.
[0046]
As a result, there is no need to work out the shaft center while rotating the shaft 108, so that the assembly efficiency can be improved.
[0047]
In this embodiment, when the first guide portion 117 is lightly press-fitted into the second guide portion 118, the inward radial force applied to the first guide portion 117 by light press-fitting. Slight deformation that occurs is absorbed by the flange 116, and the shaft center is determined by the processing accuracy of the first guide portion 117 and the second guide portion 118. Therefore, the shaft center of the auxiliary bearing 114 is the same as the shaft center of the main bearing 115. It is possible to obtain an effect that they are well matched, the load is evenly distributed, and the sliding loss is reduced.
[0048]
In addition, since the gap between the first guide portion 117 and the second guide portion 118 that causes variation is eliminated, an effect of suppressing the occurrence of variation in energy efficiency due to variation during assembly can be obtained.
[0049]
(Embodiment 4)
FIG. 4 is a cross-sectional view of the main part in the vicinity of the fitting portion between the cylinder block and the main bearing in the hermetic compressor according to the fourth embodiment.
[0050]
As shown in FIG. 4, the present embodiment is provided in the hermetic compressor according to the second embodiment on the inner peripheral side of the first guide portion 117 in the main bearing 115 and shares the axis with the main bearing 511. It is provided with a groove 123 to be
[0051]
For example, the groove 123 is formed by cutting the flange 116 in the main bearing 115 into a ring shape.
[0052]
As a result, the deformation is absorbed in the vicinity of the groove 123 in the main bearing 115, particularly in the vicinity of being fixed with screws, rivets, etc., so that the effect of further reducing the thermal deformation of the sliding portion in the main bearing 115 during operation is obtained. It is done.
[0053]
(Embodiment 5)
FIG. 5 is a cross-sectional view of the main part in the vicinity of the fitting portion between the cylinder block and the main bearing in the hermetic compressor according to the fifth embodiment.
[0054]
As shown in FIG. 5, the present embodiment is provided in the hermetic compressor according to the second embodiment and is provided on the inner peripheral side of the first guide portion 117 in the main bearing 115 and shares the axis with the main bearing 115. The groove 124 is provided.
[0055]
For example, the groove 124 is formed by cutting the flange 116 of the main bearing 115 into a ring shape.
[0056]
As a result, the deformation is absorbed in the entire circumference of the main bearing 115 in the vicinity of the groove 124, so that the effect of reducing the thermal deformation of the sliding portion of the main bearing 115 during operation can be obtained.
[0057]
As described above, the main bearings made of the aluminum material have been described in the first to fifth embodiments. However, even when the main bearing is made of a material having the same linear expansion coefficient as that of the cylinder block, for example, a combination of the same cast irons, sliding is possible. Needless to say, effects other than reducing the thermal deformation of the portion can be obtained similarly.
[0058]
【The invention's effect】
As described above, the invention according to claim 1 has an effect that the shaft center of the auxiliary bearing substantially coincides with the shaft center of the main bearing, the load is evenly distributed, and the sliding loss is reduced. Further, a material different from that of the cylinder block can be used for the main bearing, and there is an effect that the friction coefficient for obtaining higher energy efficiency is lowered and the sliding loss is reduced. Also, the temperature rise during operation prevents the sub-bearing shaft center from deviating from the main bearing shaft center, evenly distributes the load, reduces sliding loss, and does not cause sliding loss due to metal contact. effective.
[0059]
The invention described in claim 2 has an effect that the efficiency of assembly is further improved in addition to the effect of the invention described in claim 1. In addition, there is an effect of reducing thermal deformation of the sliding portion in the main bearing during operation.
[0060]
The invention described in claim 3 has an effect that the efficiency of assembly is further improved in addition to the effect of the invention described in claim 1.
[0061]
The invention according to claim 4 has the effect of further reducing the thermal deformation of the sliding portion of the main bearing during operation in addition to the effect of the invention according to claim 2.
[0062]
In addition to the effect of the invention described in claim 3, the invention described in claim 5 further has an effect of reducing thermal deformation of the sliding portion of the main bearing during operation.
[0063]
In addition to the effect of the invention described in claim 2, the invention according to claim 6 further has the shaft center of the sub-bearing coincide with the shaft center of the main bearing with high accuracy, and the load is evenly distributed. This has the effect of reducing loss. In addition, there is an effect of suppressing the occurrence of variations in energy efficiency resulting from variations during assembly.
[0064]
In addition to the effect of the invention according to claim 7, the invention according to claim 7 further has the shaft center of the sub-bearing coincide with the shaft center of the main bearing with high accuracy, and the load is evenly distributed, and the sliding This has the effect of reducing loss. In addition, there is an effect of suppressing the occurrence of variations in energy efficiency resulting from variations during assembly.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a hermetic compressor according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view of a main part of a hermetic compressor according to a second embodiment of the present invention. FIG. 4 is a cross-sectional view of a main part of a hermetic compressor according to a third embodiment. FIG. 4 is a cross-sectional view of a main part of a hermetic compressor according to a fourth embodiment of the present invention. Cross-sectional view of main part [Fig. 6] Vertical cross-sectional view of a conventional hermetic compressor [Fig. 7] Top view of a conventional hermetic compressor [Explanation of symbols]
106 Eccentric shaft portion 107 Sub shaft portion 108 Main shaft portion 109 Shaft 110 Compression chamber 111 Cylinder block 114 Sub bearing 115 Main bearing 116 Flange 117 First guide portion 118 Second guide portions 119, 122 Inner diameter surface 120, 121 Outer diameter surface 123,124 groove

Claims (7)

A shaft having an eccentric shaft portion and a sub shaft portion and a main shaft portion provided coaxially above and below the eccentric shaft portion, a cylinder block having a substantially cylindrical compression chamber, and the cylinder block integrally A secondary bearing formed to support the auxiliary shaft portion and a main bearing made of an aluminum material fixed to the cylinder block and supporting the main shaft portion, and extending in a radial direction of the main shaft of the main bearing. A first guide portion having a diameter sharing the shaft center with the main bearing is provided on the flange, and a second guide portion having a diameter sharing the shaft center with the auxiliary bearing is provided on the cylinder block. A hermetic compressor having a portion fitted to the second guide portion. The hermetic compressor according to claim 1, wherein an inner diameter surface of the first guide portion and an outer diameter surface of the second guide portion are adjacent to each other. The hermetic compressor according to claim 1, wherein the outer diameter surface of the first guide portion and the inner diameter surface of the second guide portion are adjacent to each other. The hermetic compressor according to claim 2, further comprising a groove provided on an inner peripheral side of the first guide portion in the main bearing and sharing a shaft center with the main bearing. The hermetic compressor according to claim 3, further comprising a groove provided on an inner peripheral side of the first guide portion in the main bearing and sharing a shaft center with the main bearing. The hermetic compressor according to claim 2, wherein the first guide part is lightly press-fitted into the second guide part. The hermetic compressor according to claim 3, wherein the first guide part is lightly press-fitted into the second guide part.

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