JP2004137926A - Hermetic compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce sliding loss in a hermetic compressor. <P>SOLUTION: A first guide part 117 whose diameter holds an axial center in common with a main bearing 115 is arranged on a flange 116 extended in the radial direction of the main spindle of the main bearing 115, and also a second guide part 118 whose diameter holds an axial center in common with an auxiliary bearing 114 is arranged in a cylinder block 111. The first guide part 117 is fitted to the second guide part 118 so as to restrict a degree of freedom, thereby the axial center of the auxiliary bearing 114 is approximately matched with the axial center of the main bearing 115, loads are distributed equally, and the sliding loss can be reduced. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
TECHNICAL FIELD The present invention relates to a hermetic compressor used for a refrigerator, an air conditioner, a refrigerator, or the like.
[0002]
[Prior art]
2. Description of the Related Art In recent years, for hermetic compressors used in refrigeration systems such as home refrigerators, it has been strongly desired to reduce power consumption and reduce noise. Under these circumstances, the viscosity of lubricating oil has been reduced, and the rotation of a compressor driven by an inverter has been reduced (for example, in the case of a household refrigerator, about 1200 r / min).
[0003]
On the other hand, it has been premised that a natural refrigerant having a low global warming coefficient represented by R134a or R600a having an ozone depletion coefficient of zero is used, such as a hydrocarbon-based refrigerant.
[0004]
The method of using a double-sided bearing that holds a shaft at two or more locations, which has been adopted in the past, is effective as an elemental technology for reducing sliding loss and vibration and noise during operation.
[0005]
As a conventional hermetic compressor, there is one in which a separate auxiliary bearing is fixed to the upper portion of a compression section with a screw (for example, see Patent Document 1).
[0006]
Hereinafter, the conventional hermetic compressor described above 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 main part top view of the conventional hermetic compressor with the upper container removed.
[0008]
6 and 7, an electric space 5 surrounded by an airtight container 1 is driven by an electric element 5 including a stator 3 having a winding part 3 a and a rotor 4, and an electric element 5. It houses the compression element 6. The lubricating oil 8 is stored in the closed container 1.
[0009]
The shaft 10 has a main shaft portion 11 to 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. A sub bearing 19 that supports the sub shaft portion 13 is fixed upward with three screws 20. The piston 19 is reciprocally slidably inserted into the compression chamber 16 of the cylinder block 15, 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 part 12 is transmitted to the piston 19 via the connecting means 21, so that the piston 19 reciprocates in the compression chamber 16. Thereby, the refrigerant gas is sucked and compressed from the cooling system (not shown) into the compression chamber 16, and then is discharged again to the cooling system.
[0013]
Here, a mechanism for reducing the sliding loss of the double-ended 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 via the connecting means 21. Here, in the double-supported bearing type, since the load is received by both the upper and lower bearings centering on the eccentric portion 12 (action point) to which the compressive load from the piston 19 is applied, a substantially uniform load is distributed to the bearings vertically. In addition, since the bearing comes into contact with the surface, unlike the cantilever bearing type in which the inner circumference is twisted, the load distribution of the sliding portion of the shaft 10 becomes uniform, thereby reducing the surface pressure and shortening the sliding length as compared with the cantilever type. be able to. As a result, the sliding loss is reduced and the compressor efficiency is improved.
[0015]
[Patent Document 1]
JP-A-61-118571
[Problems to be solved by the invention]
However, in the above-described conventional configuration, since the main bearing 17 and the cylinder block 15 have an integral structure, a material different from that of the cylinder block 15 cannot be used for the main bearing 17, and in order to obtain further high energy efficiency. There is a possibility that the friction coefficient cannot be reduced and the sliding loss cannot be reduced.
[0017]
In the above-described conventional configuration, when the auxiliary bearing 18 is made of a material having a different linear expansion coefficient from the material of the cylinder block 15, the temperature of the auxiliary bearing 18 is shifted from the axis of the main bearing 17 due to a temperature rise during operation. Because of the displacement, the load was not evenly distributed, the sliding loss did not decrease, and there was a possibility that sliding loss due to metal contact occurred.
[0018]
Further, in the above-described conventional configuration, since the fixing is performed only with the three screws 20, the axis of the sub bearing 18 does not coincide with the axis of the main bearing 17, so that the load is not evenly distributed and the sliding loss does not decrease. There was a possibility.
[0019]
Further, in the above-described conventional configuration, when the sub-bearing 18 is fixed to the cylinder block 15 when assembling the compression element 6, the shaft 10 must be rotated to assemble the shaft 10 so that the shaft center is substantially brought out. Was inefficient.
[0020]
Further, in the above-described conventional configuration, when the auxiliary bearing 18 is fixed to the cylinder block 15, there is a possibility that variations in energy efficiency due to variations during assembly may occur.
[0021]
An object of the present invention is to solve the above-mentioned conventional problems, and an object of the present invention is to provide a hermetic compressor having high energy efficiency and good assemblability.
[0022]
[Means for Solving the Problems]
The invention according to claim 1 of the present invention includes a shaft having an eccentric shaft portion, a sub shaft portion and a main shaft portion provided vertically coaxially with the eccentric shaft portion interposed therebetween, and a substantially cylindrical compression chamber. A cylinder block provided, a sub-bearing formed integrally with the cylinder block and supporting the sub-shaft portion, and a main bearing made of an aluminum material fixed to the cylinder block and supporting the main shaft portion, A first guide portion whose diameter is shared with the main bearing is provided on a flange extending in a radial direction of a main shaft of the main shaft of the main bearing, and a diameter of the cylinder block is shared with the sub-bearing by the first block. A second guide portion is provided, and the first guide portion is fitted to the second guide portion.
[0023]
According to the first aspect of the present invention, since the first guide portion and the second guide portion are fitted to each other to limit the degree of freedom, the axis of the sub bearing substantially coincides with the axis of the main bearing. This has the effect of uniformly distributing the load and reducing the sliding loss. The main bearing is made of an aluminum material with a low coefficient of friction, and the main bearing has a separate structure from the cylinder block, so the main bearing can be made of a material different from that of the cylinder block. This has the effect of reducing the friction coefficient and reducing the sliding loss. In addition, when the temperature rises during operation, the main bearing expands uniformly in the radial direction around the axis, so that the temperature increase during operation prevents the axis of the sub-bearing from deviating from the axis of the main bearing. The load is distributed, the sliding loss is reduced, and the sliding loss due to metal contact is prevented from occurring.
[0024]
According to a second aspect of the present invention, in addition to the first aspect, an inner diameter surface of the first guide portion and an outer diameter surface of the second guide portion are adjacent to each other. In addition to the operation of the invention of the third aspect, since there is no need to perform the operation of extending the axis while rotating the shaft, the assembly efficiency is improved. Further, during operation, the inner diameter surface of the first guide portion and the outer diameter surface of the second guide portion are separated from each other, which has an effect of reducing thermal deformation of the sliding portion of the main bearing during operation.
[0025]
According to a third aspect of the present invention, in addition to the first aspect, an outer diameter surface of the first guide portion and an inner diameter surface of the second guide portion are adjacent to each other. In addition to the operation of the invention of the third aspect, since there is no need to perform the operation of extending the axis while rotating the shaft, the assembly efficiency is improved.
[0026]
According to a fourth aspect of the present invention, in addition to the second aspect of the present invention, a groove is provided on the inner peripheral side of the first guide portion of the main bearing and shares an axis with the main bearing. In addition, in addition to the effect of the invention described in claim 2, since deformation is absorbed in the vicinity of the groove in the main bearing, particularly in the vicinity of being fixed, thermal deformation of the sliding portion in the main bearing during operation is further reduced. Has an action.
[0027]
According to a fifth aspect of the present invention, in addition to the third aspect of the present invention, a groove is provided on the inner peripheral side of the first guide portion of the main bearing and shares a central axis with the main bearing. In addition, in addition to the effect of the third aspect of the present invention, since deformation is absorbed in the entire periphery of the groove in the main bearing, there is an effect that thermal deformation of the sliding portion of the main bearing during operation is reduced.
[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 by the processing accuracy of the first guide part and the second guide part. As a result, the shaft center of the sub-bearing is accurately matched with the shaft center of the main bearing, and the load is evenly distributed and the sliding loss is reduced. In addition, since the gap between the first guide portion and the second guide portion, which is a cause of the variation, is eliminated, an effect of suppressing the variation in energy efficiency due to the variation at the time of assembly is provided.
[0029]
According to a seventh aspect of the present invention, in addition to the third aspect, the first guide portion is lightly press-fitted into the second guide portion. In addition, the flange absorbs a 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. As a result, the shaft center of the sub-bearing is accurately matched with the shaft center of the main bearing, and the load is evenly distributed and the sliding loss is reduced. In addition, since the gap between the first guide portion and the second guide portion, which is a cause of the variation, is eliminated, an effect of suppressing the variation in energy efficiency due to the variation at the time of assembly is provided.
[0030]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of a compressor according to the present invention will be described with reference to the drawings.
[0031]
(Embodiment 1)
FIG. 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 closed casing 101 houses an electric element 104 including a stator 102 having a winding part 102 a and a rotor 103, and a compression element 105 driven by the electric element 104.
[0033]
The compression element 105 includes, for example, an iron-based casting provided with a shaft 109 having a sub-shaft portion 107 and a main shaft portion 108 provided coaxially 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 serving as a connecting means 113 connecting the piston 112 and the eccentric shaft portion 106, and a sub shaft formed integrally with the cylinder block 111. A sub-bearing 114 that supports the portion 107 and a main bearing 115 that is fixed to the cylinder block 111 and that supports the main shaft portion 108 made of an aluminum material are provided.
[0034]
For fixing the main bearing 115 to the cylinder block 111, for example, screws, rivets, 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 is provided with a second guide portion 118 having a diameter sharing the axis with the sub-bearing 114. And the first guide 117 is fitted to the second guide 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 machining the main bearing 115 at the same time as machining by the rotating machine.
[0036]
For example, the second guide portion 118 has a circular shape or the like, and the shaft center can be easily shared with the sub shaft portion 107 by machining the sub shaft portion 107 at the same time as machining with the rotating machine.
[0037]
As a result, the first guide portion 117 and the second guide portion 118 are fitted to each other to limit the degree of freedom, so that the axis of the sub bearing 114 substantially coincides with the axis of the main bearing 115, and the load is evenly distributed. And 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 formed separately from the cylinder block 111, a material different from that of the cylinder block 111 can be used for the main bearing 115, thereby further increasing energy. In order to obtain efficiency, the friction coefficient can be reduced, and the sliding loss can be reduced. Further, when the temperature rises during operation, the main bearing 115 expands uniformly in the radial direction around the axis, so that the axis of the sub-bearing 114 shifts from the axis of the main bearing 115 due to the temperature rise during operation. Thus, the load is evenly distributed, the sliding loss is reduced, and the sliding loss due to metal contact can be prevented.
[0038]
(Embodiment 2)
FIG. 2 is a cross-sectional view of a main part near a fitting portion between a cylinder block and a main bearing in a hermetic compressor according to a second embodiment.
[0039]
As shown in FIG. 2, in the present embodiment, the hermetic-type compressor according to the first 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. Are adjacent. The first guide portion 117 has, for example, a ring shape formed on the outer periphery of the flange 116 so as to protrude toward the cylinder block 111. The second guide portion 118 extends, for example, in a cylindrical shape from the cylinder block 111 toward the main bearing 115.
[0040]
This eliminates the need for the operation of extending the axis while rotating the shaft 108, so that the efficiency of assembly can be improved. Further, during operation, 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, thermal deformation of the sliding portion of the main bearing 115 during operation can be reduced. Can be.
[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 pressed 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. 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 sub-bearing 114 accurately matches the shaft center of the main bearing 115, and the load is evenly distributed. As a result, the effect of reducing the sliding loss is obtained. In addition, since the gap between the first guide portion 117 and the second guide portion 118, which is a cause of variation, is eliminated, the effect of suppressing the variation in energy efficiency due to the variation during assembly can be obtained.
[0043]
(Embodiment 3)
FIG. 3 is a cross-sectional view of a main part near a fitting portion between a cylinder block and a main bearing in a hermetic-type compressor according to a third embodiment.
[0044]
As shown in FIG. 3, in the present embodiment, the hermetic compressor according to the first embodiment further includes an outer diameter surface 121 of a first guide portion 117 and an inner diameter surface 122 of a second guide portion 118. Are adjacent to each other.
[0045]
The first guide portion 117 is formed by, for example, grinding the outer periphery of the flange 116, and the second guide portion 118 is, for example, extending in a ring shape from the cylinder block 111 toward the main bearing 115.
[0046]
This eliminates the need for the operation of extending the axis while rotating the shaft 108, so that the effect of improving the efficiency of assembly is obtained.
[0047]
In the present embodiment, when the first guide portion 117 is lightly press-fitted into the second guide portion 118, an inward radial force applied to the first guide portion 117 by light press-fitting. Slight deformations are absorbed by the flange 116 and the axis is determined by the processing accuracy of the first guide portion 117 and the second guide portion 118. There is obtained an effect that the loads match well, 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, which is a cause of variation, is eliminated, the effect of suppressing the variation in energy efficiency due to the variation during assembly can be obtained.
[0049]
(Embodiment 4)
FIG. 4 is a cross-sectional view of a main part near a fitting portion between a cylinder block and a main bearing in a hermetic-type compressor according to a fourth embodiment.
[0050]
As shown in FIG. 4, in the present embodiment, the hermetic compressor according to the second embodiment 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 511. The groove 123 is provided.
[0051]
For example, the groove 123 is formed by cutting a flange 116 of the main bearing 115 into a ring shape.
[0052]
As a result, 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, or the like, so that the thermal deformation of the sliding portion of the main bearing 115 during operation can be further reduced. Can be
[0053]
(Embodiment 5)
FIG. 5 is a cross-sectional view of a main part near a fitting portion between a cylinder block and a main bearing in a hermetic-type compressor according to a fifth embodiment.
[0054]
As shown in FIG. 5, in the present embodiment, the hermetic compressor according to the second embodiment is provided on the inner peripheral side of the first guide portion 117 of 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 a flange 116 of the main bearing 115 into a ring shape.
[0056]
As a result, the deformation is absorbed around the entire circumference of the groove 124 in the main bearing 115, 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 bearing made of aluminum has been described in Embodiments 1 to 5. However, even when the main bearing is made of a material having the same linear expansion coefficient as the material of the cylinder block, for example, a combination of the same cast iron, sliding is performed. It goes without saying that effects other than reducing the thermal deformation of the part can be similarly obtained.
[0058]
【The invention's effect】
As described above, the invention according to claim 1 has an effect 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. In addition, a material different from that of the cylinder block can be used for the main bearing, and there is an effect that a friction coefficient for obtaining higher energy efficiency is reduced and a sliding loss is reduced. Also, the temperature rise during operation prevents the axis of the sub bearing from shifting from the axis of the main bearing, distributes the load evenly, reduces sliding loss, and prevents 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. Further, there is an effect that thermal deformation of a sliding portion of the main bearing during operation is reduced.
[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 described in claim 4 has the effect of further reducing the thermal deformation of the sliding portion in the main bearing during operation, in addition to the effect of the invention described in claim 2.
[0062]
The invention described in claim 5 has the effect of further reducing the thermal deformation of the sliding portion in the main bearing during operation, in addition to the effect of the invention described in claim 3.
[0063]
According to the invention of claim 6, in addition to the effect of the invention of claim 2, the axis of the sub-bearing coincides with the axis of the main bearing with high precision, the load is evenly distributed, and the sliding The effect is that the loss is reduced. In addition, there is an effect that occurrence of variation in energy efficiency due to variation during assembly is suppressed.
[0064]
According to a seventh aspect of the present invention, in addition to the effect of the third aspect, the axis of the sub-bearing coincides with the axis of the main bearing with high accuracy, the load is evenly distributed, and the sliding is performed. The effect is that the loss is reduced. In addition, there is an effect of suppressing the occurrence of energy efficiency variations caused by 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 sectional view of a main part of a hermetic compressor according to a second embodiment of the present invention; FIG. 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. Main part sectional view [Fig. 6] Longitudinal sectional view of conventional hermetic compressor [Fig. 7] Top view of conventional hermetic compressor [Description of reference numerals]
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 portion 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 vertically coaxially with the eccentric shaft portion interposed therebetween, a cylinder block having a substantially cylindrical compression chamber, and integrally with the cylinder block. A main bearing made of an aluminum material fixed to the cylinder block and supporting the main shaft portion, the sub-bearing supporting the sub-shaft portion, and extending in a radial direction of the main shaft of the main bearing. The flange is provided with a first guide portion having a diameter sharing the axis with the main bearing, and the cylinder block is provided with a second guide portion having a diameter sharing the axis with the sub-bearing, and the first guide is provided. 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 is adjacent to an outer diameter surface of the second guide portion. The hermetic compressor according to claim 1, wherein an outer diameter surface of the first guide portion is adjacent to an inner diameter surface of the second guide portion. The hermetic compressor according to claim 2, further comprising a groove provided on an inner peripheral side of the first guide portion of the main bearing and sharing a shaft center with the main bearing. 4. The hermetic compressor according to claim 3, further comprising a groove provided on an inner peripheral side of the first guide portion of the main bearing and sharing a central axis with the main bearing. 5. The hermetic compressor according to claim 2, wherein the first guide portion is lightly press-fitted into the second guide portion. The hermetic compressor according to claim 3, wherein the first guide is lightly press-fitted into the second guide.

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