JP4017853B2 - Hermetic reciprocating compressor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hermetic reciprocating compressor used in a refrigerator-freezer, a car cooler, an air conditioner, and the like.
[0002]
[Prior art]
In recent years, in the refrigeration equipment field, as a part of improving reliability, a hermetic reciprocating compressor having a chamfered opening at the compression chamber opening end has been proposed.
[0003]
As a conventional hermetic reciprocating compressor, for example, the contents shown in FIG. 1 in US Pat. No. 5,149,254 and the contents shown in FIG. 2 in Japanese Patent Laid-Open No. 2001-20864 are known.
[0004]
The conventional hermetic reciprocating compressor will be described below with reference to the drawings.
[0005]
FIG. 9 is a longitudinal sectional view of a conventional hermetic reciprocating compressor. FIG. 10 is a schematic diagram of the compression chamber of FIG. 9 and shows a compression chamber in which a cylinder head and a valve plate are attached to the compression chamber opening end. FIG. 11 is a cross-sectional view of the compression chamber of FIG. 9 and shows the compression chamber deformed by the bolt tightening force generated when the cylinder head and the valve plate are attached to the compression chamber opening end. FIG. 12 is a schematic view of the compression chamber opening end in FIG. 9 and shows a state where the piston cannot freely slide in the vicinity of the deformed compression chamber opening end. FIG. 13 is a cross-sectional view of the compression chamber of FIG. 9 and shows the compression chamber provided with a chamfer chamfer to escape the deformation of FIG. FIG. 14 is a cross-sectional view of the compression chamber of FIG. 9 and shows the compression chamber provided with a counterbore to escape the deformation of FIG. FIG. 15 is a partial cross-sectional view of the compression chamber of FIG. 9 and shows the compression chamber deformed by the bolt tightening force generated when the cylinder head and the valve plate are attached to the opening end of the compression chamber of FIG. FIG. 16 is a partial cross-sectional view of the compression chamber opening end of FIG. 9, showing the compression chamber deformed by the bolt tightening force generated when the cylinder head and the valve plate are attached to the compression chamber opening end of FIG. .
[0006]
In FIG. 9, reference numeral 1 denotes an airtight container that houses an electric element 4 composed of a stator 2, a rotor 3, and a compression element 5 driven by the electric element 4. Reference numeral 6 denotes oil stored in the sealed container 1.
[0007]
Next, details of the compression element 5 will be described below.
[0008]
7 is a cylinder block that forms a compression chamber 8. A crankshaft 9 includes a main shaft portion 9a and an eccentric shaft portion 9b. The oil pump member 18 communicates with an upper end 9c of the eccentric shaft portion 9b through an oil supply passage, and a lower end 9d is opened in the oil 6. is doing. 9e is a bearing groove that communicates with the upper end of the oil pump member 18 and is provided on the outer wall of the main shaft portion 9a of the crankshaft 9. Reference numeral 9f denotes an eccentric part branch hole which communicates with the upper end of the bearing part groove 9e and is provided on the outer wall of the eccentric shaft part 9b of the crankshaft 9. A connecting rod 10 connects the eccentric shaft portion 9 b and the piston 11 via a piston pin 12. 13 is a valve plate provided with a suction hole, a suction valve, a discharge hole, and a discharge valve (all not shown), and 14 is a cylinder head divided into a suction chamber and a discharge chamber (none shown). is there. A bolt 15 fastens the valve plate 13 and the cylinder head 14 to the cylinder block 7. A suction muffler 16 communicates with the compression chamber 8 at one end. Reference numeral 17 denotes a suction tube penetrating the sealed container 1.
[0009]
The operation of the hermetic electric compressor configured as described above will be described below.
[0010]
The rotor 3 of the electric element 4 rotates the crankshaft 9, and the movement of the eccentric shaft portion 9 b is transmitted to the piston 11 through the connecting rod 10, so that the piston 11 reciprocates in the compression chamber 8 and the suction tube 17. The refrigerant gas guided into the sealed container 1 through the suction muffler 16 is sucked from the suction muffler 16 and continuously compressed in the compression chamber 8.
[0011]
On the other hand, oil 6 is stored at the bottom of the sealed container 1 to prevent abnormal wear and seizure of each sliding portion and to move smoothly. The oil 6 is sucked up by the oil pump member 18 provided at the lower end of the crankshaft 9 due to the rotation of the crankshaft 9, and further centrifugal force generated by the rotation is applied to rise to the inner wall of the crankshaft 9 shaft hole. . Ascended oil 6 is supplied to a required sliding portion through the bearing groove 9e and the eccentric branching hole 9f, and is scattered from the eccentric inner wall upper portion 9c of the shaft 9, and the inner peripheral portion of the compression chamber 8, It is divided into what is supplied to the outer periphery of the piston 11.
[0012]
Further, as shown in FIGS. 10 and 11, the opening end of the compression chamber 8 by the strong tightening force F for attaching the valve plate 13 and the cylinder head 14 to the opening end of the compression chamber 8 of the conventional hermetic reciprocating compressor. The deformation 8a occurs. The deformation amount of the deformation 8a is determined by the material rigidity and structure of the cylinder block 7, the valve plate 13, and the cylinder head 14, the tightening force F of the bolt 15, and is generally about 1 to 10 μm, and is shown in FIG. As described above, the piston 11 becomes an obstacle for freely reciprocatingly sliding in the vicinity of the opening end of the compression chamber 8, and as a result, various problems such as abnormal wear and seizure of the piston and piston lock are caused.
[0013]
Therefore, it is known to provide a chamfer at the open end of the compression chamber 8 in order to escape the deformation 8a and prevent problems such as abnormal wear, seizure, and piston lock. In the conventional hermetic reciprocating compressor disclosed in US Pat. No. 5,149,254, a chamfer chamfer 19 having an angle β of about 45 ° to 30 ° is provided at the open end of the compression chamber 8 as shown in FIG.
[0014]
In addition, as shown in FIG. 14 in Japanese Patent Laid-Open No. 2001-20864, a counter bore 20 having an inner diameter slightly larger than the inner diameter of the compression chamber 8 is provided at the opening end of the compression chamber 8, and the bolt 15 tightening force is provided. What is missing the deformation 8a by F is shown.
[0015]
Further, in the conventional hermetic reciprocating compressor, when the piston 11 reaches the opening end of the compression chamber 8, a slight gap is provided so that the tip of the piston 11 and the valve (not shown) or the valve plate 13 do not come into contact with each other. It is. This gap is called clearance volume. In the clearance volume, some of the high-pressure refrigerant gas that has risen to the discharge pressure at the end of the compression stroke remains, and re-expands at the beginning of the suction stroke. For this reason, the refrigerant gas is not sucked until the pressure in the compression chamber 8 reaches the suction pressure, and the volume of the gas actually sucked into the compression chamber 8 becomes smaller than the displacement of the piston 11, thereby reducing the volume efficiency. In order to prevent a decrease in volumetric efficiency, a dead volume such as a clearance volume must be reduced so that re-expansion is reduced.
[0016]
[Problems to be solved by the invention]
However, the conventional configuration described above has a chamfer chamfer 19 attached to the opening end of the compression chamber 8 to sufficiently release the deformation 8a of the opening end of the compression chamber 8 due to the tightening force F of the bolt 15 and improve the reliability. If it is increased, the dead volume is increased and the volume efficiency is decreased. Therefore, in order to reduce the dead volume, the chamfer chamfering is generally set to about 0.1 to 0.4 mm at 45 °, for example. However, in the chamfer chamfering of such a size, as shown in FIG. 15, a deformation 19 a of 0.5 to 4 μm remains in the inner diameter direction near the opening end of the compression chamber 8. In this configuration, the deformation 19a becomes an obstacle to free sliding in the vicinity of the opening end of the compression chamber 8 of the piston 11, and there is a drawback that abnormal wear and seizure of the piston are likely to occur and reliability is low.
[0017]
The present invention solves the conventional problems. The deformation 8a of the opening end of the compression chamber 8 due to the tightening force F of the bolt 15 is sufficiently released, and the piston 11 can freely reciprocate in the compression chamber 8. An object of the present invention is to provide a hermetic reciprocating compressor in which abnormal wear and seizure are eliminated and reliability is improved.
[0018]
Further, in the conventional configuration shown in FIG. 14, the deformation 8a of the opening end of the compression chamber 8 due to the tightening force F of the bolt 15 is suppressed, and a counter bore 20 is attached to the opening end of the compression chamber 8 in order to improve reliability. However, as shown in FIG. 16, the length of the counterbore piston 11 in the reciprocating direction is generally set to 1.6 to 2.2 mm in order to sufficiently release the deformation 20a. Therefore, in this configuration, the reliability is high, but the space D becomes a dead volume. This dead volume is large because the length of the piston 11 in the reciprocating direction is long, and as a result, the volumetric efficiency of the hermetic reciprocating compressor is low.
[0019]
Another object of the present invention is to provide a hermetic reciprocating compressor in which dead volume is reduced and volume efficiency is improved.
[0020]
[Means for Solving the Problems]
According to a first aspect of the present invention, oil is stored in a sealed container and a compression element driven by an electric element is accommodated. The compression element includes a main shaft portion and an eccentric shaft portion, and communicates with the upper end of the eccentric shaft portion. A crankshaft having a built-in oil pump member, a cylinder block that supports the main shaft portion of the crankshaft and has a substantially cylindrical compression chamber, a substantially cylindrical piston that reciprocates in the compression chamber, and the crank A connecting rod for connecting the eccentric shaft portion of the shaft and the piston is included in the structure of the compression element, and the cylinder head is fastened to the end portion on the entire inner periphery of the end portion on the cylinder head side of the compression chamber . to the extent that escape the deformation of said end portion, toward the opposite side of the cylinder head on the end portion of the cylinder head side, successively its inner diameter is increased That having thereon a trumpet-shaped chamfer, relief deformation of the end portion of the cylinder head side of the compression chamber, eliminating the piston abnormal wear or seizure, in addition capable of improving reliability, and reducing the dead volume, The volume efficiency can be improved.
[0021]
According to a second aspect of the present invention, an oil pump that stores oil in a sealed container and accommodates a compression element that is driven by an electric element, includes a main shaft portion and an eccentric shaft portion, and communicates with the upper end of the eccentric shaft portion. A crankshaft having a built-in member; a cylinder block that supports the main shaft portion of the crankshaft and has a substantially cylindrical compression chamber; a substantially cylindrical piston that reciprocates in the compression chamber; and an eccentricity of the crankshaft A connecting rod that connects the shaft portion and the piston is included in the configuration of the compression element, so that the deformation of the end portion when the cylinder head is fastened to the end portion is released to the entire outer periphery of the piston tip . are those sequentially its outer diameter toward the distal end from the opposite distal end of the piston is provided with a counter-flaring chamfered to decrease, the compression chamber cylinder Relief deformation of the end portion of the head side, eliminating the piston abnormal wear or seizure, in addition capable of improving reliability, and reducing the dead volume, has an effect that it is possible to improve the volumetric efficiency.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of a hermetic reciprocating compressor according to the present invention will be described below with reference to the drawings. In addition, about the same structure as the past, the same code | symbol is attached | subjected and detailed description is abbreviate | omitted.
[0023]
(Embodiment 1)
FIG. 1 is a longitudinal sectional view of a hermetic reciprocating compressor according to Embodiment 1 of the present invention, FIG. 2 is a sectional view of a compression chamber of the hermetic reciprocating compressor of the same embodiment, and FIG. It is a fragmentary sectional view of the cylinder head side end part of the compression chamber of a closed type reciprocating compressor. FIG. 4 is a partial cross-sectional view of the cylinder head side end of the compression chamber of the hermetic reciprocating compressor according to the embodiment, and compares the dead volume of the compression chamber.
[0024]
1, 2, 3, and 4, the compression element 21 has a cylinder block 22 that forms a substantially cylindrical compression chamber 23. Reference numeral 23a denotes a trumpet chamfer whose inner diameter dimension increases sequentially toward the end of the compression chamber 23 on the cylinder head 14 side .
[0025]
The trumpet chamfer 23a is a convex curved surface formed of at least one smooth R surface, a free curved surface, or the like that touch each other. Further, in order to sufficiently release the deformation of the end on the head 14 side to the cylinder of the compression chamber 23 due to the tightening force F of the bolt 15, the curvature radius of the convex chamfering is closer to the end of the compression chamber 23 to the cylinder on the head 14 side. Becomes smaller. That is, the relationship between the radii of curvature R1, R2, and R is R1>R2> R3.
[0026]
The operation of the hermetic reciprocating compressor configured as described above will be described below.
[0027]
In the present embodiment, a trumpet chamfer 23a provided in the vicinity of the end of the compression chamber 23 on the cylinder head 14 side, the inner diameter dimension of which gradually increases from the opposite side of the cylinder head 14 toward the end of the cylinder head 14 side. However, since the deformation of the end of the compression chamber 23 on the cylinder head 14 side is sufficiently released, the oil film does not break in the gap between the compression chamber 23 and the piston 11, and therefore, abnormal wear and seizure of the piston can be prevented. Can be improved. [0028]
Also, as shown in FIG. 4, when the counterbore, chamfer chamfer, and trumpet chamfer 23a of the present embodiment are installed in the direction of the piston reciprocating motion, the space that becomes a dead volume is set in the counterbore. Whereas A + B + C and chamfer chamfering are B + C, the trumpet chamfer 23a is only C, and the dead volume can be kept extremely small, and the volumetric efficiency can be greatly improved.
[0029]
(Embodiment 2)
5 is a longitudinal sectional view of a hermetic reciprocating compressor according to a second embodiment of the present invention, FIG. 6 is a schematic diagram of a piston of the hermetic reciprocating compressor of the same embodiment, and FIG. 7 is a hermetic sealing of the same embodiment. FIG. 8 is a schematic diagram of the piston tip of the closed-type reciprocating compressor according to the embodiment and the cylinder head side end of the compression chamber.
[0030]
In FIGS. 5, 6, 7, and 8, the compression element 24 includes a cylinder block 26 that forms a substantially cylindrical compression chamber 25 and a substantially cylindrical piston 27. Reference numeral 27 a denotes an anti-trumpet chamfer in which the inner diameter dimension decreases gradually toward the tip of the piston 27.
[0031]
The anti-trumpet chamfer 27a is a convex curved surface composed of at least one smooth R surface, a free curved surface, or the like that touch each other. Further, in order to sufficiently release the deformation of the end portion on the cylinder head 14 side of the compression chamber 25 due to the tightening force F of the bolt 15, the curvature radius of the convex chamfer becomes smaller as it is closer to the tip of the piston 27. That is, the relationship between the curvature radii R1, R2, and R3 is R1>R2> R3.
[0032]
The operation of the hermetic reciprocating compressor configured as described above will be described below.
[0033]
As shown in FIG. 8, in the present embodiment, an anti-trumpet chamfer 27a provided in the vicinity of the tip of the piston 27 and gradually reducing its inner diameter toward the tip is the end of the compression chamber 25 on the cylinder head 14 side. By sufficiently escaping the deformation 25a, the oil film between the compression chamber 25 and the piston 27 is not cut, and therefore, abnormal wear and seizure of the piston can be prevented, and the reliability can be improved.
[0034]
Further, as shown in FIG. 8, the compression chamber 25 has an anti-trumpet shape in accordance with the shape of the deformation 25a at the end on the cylinder head 14 side, so that the clearance between the piston 27 and the deformation 25a is reduced. The volumetric efficiency can be greatly improved by narrowing and almost no dead volume.
[0035]
As described above, the invention according to claim 1 stores oil in a sealed container and accommodates a compression element driven by an electric element, and includes a main shaft portion and an eccentric shaft portion, and the upper end of the eccentric shaft portion. A crankshaft incorporating an oil pump member communicating with the cylinder shaft, a cylinder block that pivotally supports the main shaft portion of the crankshaft and has a substantially cylindrical compression chamber, a substantially cylindrical piston that reciprocates in the compression chamber, A connecting rod for connecting the eccentric shaft portion of the crankshaft and the piston is included in the configuration of the compression element, and the cylinder head is fastened to the end portion in the vicinity of the end portion on the cylinder head side of the compression chamber. the extent to release the deformation of the end portion, toward the end of the cylinder head side from the opposite side of the cylinder head, successively its inner diameter And at the trumpet-shaped chamfer increasing one provided on the entire circumference of the end portion of the cylinder head side, relief deformation of the end portion of the cylinder head side of the compression chamber, eliminating the piston abnormal wear or seizure, improve reliability In addition, the dead volume can be reduced and the volume efficiency can be improved.
[0036]
According to a second aspect of the present invention, oil is stored in a sealed container and a compression element driven by an electric element is accommodated. The compression element is composed of a main shaft portion and an eccentric shaft portion, and communicates with the upper end of the eccentric shaft portion. A crankshaft incorporating an oil pump member; a cylinder block that supports the main shaft portion of the crankshaft and has a substantially cylindrical compression chamber; a substantially cylindrical piston that reciprocates in the compression chamber; and the crankshaft A connecting rod connecting the eccentric shaft portion of the piston and the piston is included in the configuration of the compression element, and the deformation of the end portion when the cylinder head is fastened to the end portion is released in the vicinity of the piston tip end. are those sequentially its outer diameter toward the tip is provided with a counter-flaring chamfered to decrease outside the entire circumference of the piston tip, the compression chamber Siri Relief deformation of the end of Daheddo side, eliminating the piston abnormal wear or seizure, in addition capable of improving reliability, and reducing the dead volume, it is possible to improve the volumetric efficiency.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a hermetic reciprocating compressor according to a first embodiment of the present invention. FIG. 2 is a sectional view of a compression chamber of the same embodiment. FIG. 3 is a cylinder head side of the compression chamber of the same embodiment. partial cross-sectional view of an end portion longitudinal sectional view of a hermetic reciprocating compressor according to a second embodiment of Figure 4 is a partial cross-sectional view of the cylinder head-side end portion of the compression chamber of the same embodiment the present invention; FIG Figure 6] Schematic diagram of the piston of the embodiment. [FIG. 7] Schematic diagram of the piston tip of the embodiment. [FIG. 8] Schematic diagram of the piston tip of the embodiment and the cylinder head side end of the compression chamber. 9] Vertical sectional view of a conventional hermetic reciprocating compressor [Fig. 10] Schematic diagram of a compression chamber of a conventional hermetic reciprocating compressor [Fig. 11] Cross sectional view of a compression chamber of a conventional hermetic reciprocating compressor [Fig. ] stands for the cylinder head-side end portion of the compression chamber of the conventional hermetic reciprocating compressor Figure 13 shows the conventional hermetic cross-sectional view of the compression chamber reciprocating compressor 14 is a cross-sectional view of a compression chamber of the conventional hermetic reciprocating compressor [15] compression chamber of the conventional hermetic reciprocating compressor Partial sectional view of the cylinder head side end [FIG. 16] Partial sectional view of the cylinder head side end of the compression chamber of the conventional hermetic reciprocating compressor [description of symbols]
DESCRIPTION OF SYMBOLS 1 Airtight container 4 Electric element 6 Oil 9 Crankshaft 9a Main shaft part 9b Eccentric shaft part 10 Connecting rod 11 Piston 18 Oil pump member 21 Compression element 22 Cylinder block 23 Compression chamber 23a Trumpet chamfer 24 Compression element 25 Compression chamber 26 Cylinder Block 27 Piston 27a Anti-trumpet chamfer

Claims (2)

A crankshaft that stores oil in an airtight container and accommodates a compression element that is driven by an electric element, includes a main shaft portion and an eccentric shaft portion, and includes an oil pump member that communicates with the upper end of the eccentric shaft portion; and A cylinder block that supports the main shaft portion of the crankshaft and has a substantially cylindrical compression chamber, a substantially cylindrical piston that reciprocates in the compression chamber, and a connecting portion that connects the eccentric shaft portion of the crankshaft and the piston. The rod is included in the configuration of the compression element, and the cylinder is so formed as to release deformation of the end when the cylinder head is fastened to the end on the entire inner periphery of the end of the compression chamber on the cylinder head side. from the opposite side of the head toward the end of the cylinder head side, successively sealed having a trumpet-shaped chamfer which the inner diameter is increased Cipro compressor. A crankshaft that stores oil in an airtight container and accommodates a compression element that is driven by an electric element, includes a main shaft portion and an eccentric shaft portion, and includes an oil pump member that communicates with the upper end of the eccentric shaft portion; and A cylinder block that supports the main shaft portion of the crankshaft and has a substantially cylindrical compression chamber, a substantially cylindrical piston that reciprocates in the compression chamber, and a connecting portion that connects the eccentric shaft portion of the crankshaft and the piston. A rod is included in the configuration of the compression element, and the tip from the non -tip side of the piston is released to the extent that the deformation of the end when the cylinder head is fastened to the end is released on the entire outer periphery of the piston tip. A hermetic reciprocating compressor with an anti-trumpet chamfer that gradually decreases in outer diameter toward the end.

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