JP2012041879A - Hermetic compressor and refrigerator using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hermetic compressor capable of enhancing the efficiency and the reliability of the compressor by improving the lubricating oil holding capacity between a piston and a cylinder, and to provide a refrigerator having the same.SOLUTION: The hermetic compressor has compressing elements and electric elements accommodated in the hermetic container, wherein the compressing elements have the piston and the cylinder, the lower end of the crankshaft driven by the electric elements is dipped into the lubricating oil stored in the hermetic container, the lubricating oil is raised by the centrifugal force of the oil pump arranged in the lower end of the crankshaft, and supplies the lubricating oil jetting out from the oil supplying hole of the eccentric shaft eccentrically formed in the upper part of the crankshaft between the cylinder and the piston. The compressor has the lubricating oil supplying part arranged in the cylinder and the lubricating oil storing part arrange in the piston, and the gas releasing part suppressing the stagnation of coolant gas in the lubricating oil storing part when the lubricating oil is supplied from the lubricating oil supplying part to the lubricating oil storing part in the cylinder.

Description

  The present invention relates to a hermetic compressor and a refrigerator using the same.

  Conventionally, an oil supply structure for a sliding surface formed between a cylinder and a piston of a hermetic compressor is provided with a notch on the upper surface of the cylinder as described in, for example, Patent Document 1, and this notch The lubricating oil is blown from the drive shaft toward the piston, and the lubricating oil is scattered on the piston, and the oil is supplied to the sliding surface between the cylinder and the piston.

JP 2006-283770 A

  In the above-described hermetic compressor disclosed in Patent Document 1, by rotating the crankshaft, the lubricant is sucked and injected from the eccentric shaft above the crankshaft toward the notch provided in the cylinder block. In addition, since the annular oil groove on the outer periphery of the piston is set to protrude from this notch, the lubricant always accumulates in the oil groove when the piston is at the bottom dead center, and the piston and the piston when compressed (top dead center). Lubricating oil is supplied between the cylinder.

  However, this oil supply structure has the following problems. Since the annular oil groove on the outer periphery of the piston that opens to the notch provided in the cylinder block is only a part and most of the groove is closed by the cylinder block, if there is gas in the annular oil groove, Since there was no escape, it was difficult to sufficiently introduce oil into the oil supply groove.

  In addition, oil is supplied between the piston and cylinder only while the lubricating oil reaches the side surface of the notch of the cylinder, and is not always supplied during one rotation of the rotating shaft, and the oil supply time is short. It has become.

  Furthermore, since the upper wall of the cylinder is greatly cut into a semicircular arc shape, the cost for the notch processing increases, and the piston seal width decreases, so that the compressed refrigerant flows from the compression chamber formed by the cylinder and the piston. It is easy to leak into the closed container space outside the cylinder.

  Therefore, the formation of an oil film between the piston and the cylinder becomes insufficient, the sealing performance is lowered, the amount of compressed gas leaked from the compression chamber is increased, the efficiency of the compressor is lowered, and the lubricity of the sliding portion between the piston and the cylinder is reduced. There is a problem that the reliability of the compressor is likely to be lowered due to a decrease in the pressure.

  Therefore, an object of the present invention is to provide a hermetic compressor that can improve the efficiency and reliability of the compressor by improving the lubricating oil retention between the piston and the cylinder, and a refrigerator including the same.

  In order to solve the above problems, for example, the configuration described in the claims is adopted. The present application includes a plurality of means for solving the above-described problems. For example, the application includes a compression element and an electric element housed in a sealed container, and the compression element includes a piston and a cylinder, and the electric element The lower end of the crankshaft driven by the cylinder is immersed in the lubricating oil stored in the sealed container, and the lubricating oil is raised by the centrifugal force of an oil pump provided at the lower end of the crankshaft. In a hermetic compressor for supplying the lubricating oil ejected from an oil supply hole of an eccentric shaft eccentrically formed between the cylinder and the piston, a lubricating oil supply section provided in the cylinder, and a lubrication provided in the piston An oil holding portion, and when the lubricating oil is supplied from the lubricating oil supply portion to the lubricating oil holding portion, the gas vent portion that suppresses the retention of the refrigerant gas in the lubricating oil holding portion Characterized by comprising the da.

  According to the present invention, it is possible to provide a hermetic compressor capable of improving the efficiency and reliability of the compressor by improving the lubricating oil retention between the piston and the cylinder, and a refrigerator including the same.

1 is a longitudinal sectional view of a hermetic compressor according to a first embodiment of the present invention. It is AA sectional drawing of FIG. It is a longitudinal cross-sectional view of the refrigerator in which the hermetic type compressor concerning this embodiment was carried. It is a principal part expanded sectional view near piston bottom dead center position. It is a principal part expanded sectional view of piston top dead center position vicinity. It is the cylinder block side view which looked at the cylinder side from the spindle center. It is a perspective view which shows the lubricating oil supply part formed in the cylinder bore inner wall in FIG. It is a cylinder block appearance perspective view of a hermetic compressor concerning this embodiment. It is a BB cross-sectional schematic diagram of FIG. 4 explaining the lubricating oil retainability of the piston according to the present embodiment. It is a principal part expanded sectional view of the hermetic compressor concerning a 2nd embodiment of the present invention. It is a perspective view which shows the oil supply hole position penetrated and formed in the cylinder inner wall in FIG.

(Embodiment 1)
Hereinafter, a first embodiment of the present invention will be described in detail with reference to FIGS. First, the overall configuration will be described with reference to FIGS. 1 is a longitudinal sectional view of a hermetic compressor according to the first embodiment of the present invention, FIG. 2 is a sectional view taken along the line AA of FIG. 1, and FIG. 3 is a state where the hermetic compressor according to the present embodiment is mounted. It is a longitudinal cross-sectional view of a refrigerator.

  In FIG. 3, the hermetic compressor 50 of this embodiment is mounted on a refrigerator 60. The refrigerator main body 61 includes a cooler 66 and uses a natural refrigerant R600a having a small warming coefficient. In addition, it has an internal space consisting of a refrigerator compartment 62, an upper freezer compartment 63, a lower freezer compartment 64, and a vegetable compartment 65, and the hermetic compressor 50 and the cooler are connected by a refrigerant pipe, and a refrigerating cycle (not shown). It is cooled by operating.

  The hermetic compressor 50 of the present embodiment houses an electric element 2 and a compression element 3 including a stator 2 a and a rotor 2 b in a hermetic container 1. In the compression element 3, the piston 7 connected to the eccentric shaft 8b of the crankshaft 8 by the connecting rod 6 reciprocates in the cylinder 5a formed in the cylinder block 5 in which the bearing portion 5c and the frame portion 5b are integrally formed. This is a so-called reciprocating type. The crankshaft 8 is fixed to the rotor 2 b of the electric element 2 at the lower part of the main shaft 8 a that is rotatably fitted to the bearing portion 5 c of the cylinder block 5. The compression element 3 is elastically supported on the bottom of the hermetic container 1 by a coil spring via a stator 2a of the electric element 2 fixed to the lower part of the frame part 5b.

  As the rotor 2b of the electric element 2 rotates, the crankshaft 8 rotates, and the piston 7 reciprocates in the bore of the cylinder 5a via the connecting rod 6 that is eccentrically rotated and connected to the eccentric shaft 8b. It has become.

  The upper end portion of the cylinder 5 a is closed by a cylinder head 10 in which a suction valve and a discharge valve (not shown) are incorporated, and a compression chamber 12 is formed between the cylinder 5 a and the piston 7. In the compression chamber 12, the refrigerant is sucked and compressed by the reciprocating motion of the piston 7 and discharged from the discharge valve.

  Note that the lubricating oil 4 stored at the bottom of the sealed container 1 is pulled up by the centrifugal pump action of the oil pump 8 c attached to the lower end of the crankshaft 8 by the rotation of the crankshaft 8. The ball joint portion connected to the piston 7 and the large end bearing portion of the connecting rod 6 guided upward through a spiral groove formed on the outer periphery of the main shaft 8a and further rotatably fitted to the eccentric shaft 8b. Lubricating is performed and injected from a lubricating oil radiation hole 8bb provided so as to partially penetrate a balance weight 9 attached to the upper end of the eccentric shaft 8b, and finally injected from the upper end portion of the eccentric shaft 8b to the periphery. Lubrication and sealing between the piston 7 and the cylinder 5a are mainly performed by the injected lubricating oil 4.

  The refrigerant that has flowed in through the suction pipe 16 connected in the sealed container 1 passes through the plastic suction silencer 17 and enters the compression chamber 12 of the cylinder 5a. The compressed refrigerant enters the discharge chamber in the head cover 11 from the cylinder head 10, passes through the discharge silencer 18 formed integrally with the cylinder block 5 from here, passes through the discharge pipe 19, and is provided outside the discharge pipe 20. It flows out to the refrigeration cycle.

  Next, the oil supply structure between the piston and the cylinder bore will be described in detail with reference to FIGS. 4 is an enlarged cross-sectional view of the main part near the piston bottom dead center position, FIG. 5 is an enlarged cross-sectional view of the main part near the piston top dead center position, and FIG. 6 is a side view of the cylinder block as seen from the center of the spindle. FIG. 8 is a perspective view showing a lubricating oil supply section formed on the inner periphery of the cylinder bore in FIG. 6, FIG. 8 is a perspective view of the cylinder block of the hermetic compressor according to the present embodiment, and FIG. 9 is a piston lubrication according to the present embodiment. It is a BB cross section schematic diagram of Drawing 4 explaining oil retention.

  Two annular grooves 15 are formed on the outer periphery of the piston 7 of the present embodiment as a lubricating oil holding portion. Between the inner peripheral surface of the cylinder 5a and the outer peripheral surface of the piston 7 is a sliding surface, and the bore inner diameter of the cylinder 5a is generally larger than the outer diameter of the piston 7 by about 10 μm in the diameter gap. . The annular groove 15 is recessed from the outer peripheral surface of the piston 7 by about 50 μm, and holds lubricating oil in the space in the groove. The holding amount of the lubricating oil 4 is determined by the width and depth dimensions of the annular groove 15. When the groove depth is about 50 μm, the width dimension is about 1 mm, but these dimensional relationships can be arbitrarily set.

  An oil reservoir 13 for receiving the lubricating oil 4 scattered from the eccentric shaft 8b of the crankshaft 8 by the partition wall 13a is provided on the upper surface of the outer periphery of the cylinder 5a, and the bottom surface of the oil reservoir 13 is the crankshaft 8 By inclining toward the side, lubricating oil is supplied to the sliding surfaces of the cylinder and the piston 7.

  When the piston 7 is positioned near the bottom dead center, as shown in FIG. 4, the annular groove 15 on the lower side of the piston 7 is chamfered in two stages by changing the chamfering angle on the main shaft side end surface of the cylinder 5a. The annular groove 15 on the upper (top) side of the piston 7 is opened through a taper groove 14 of a lubricating oil supply part formed on the upper inner wall of the cylinder 5a. It opens to the space inside the sealed container 1. The lubricating oil 4 pumped up by the rotation of the crankshaft 8 is injected from the lubricating oil radiation hole 8bb of the eccentric shaft 8b, passes through the taper groove 14 positioned substantially at the same height as the lubricating oil radiation hole 8bb, and is located above the piston 7. To the annular groove 15. A reference numeral 15 ′ in FIG. 7 indicates a groove width position in the vicinity of the bottom dead center of the annular groove 15 on the upper side of the piston 7 by a two-dot chain line, and shows a state of communicating with the tapered groove 14.

  When the piston 7 is located near the top dead center, as shown in FIG. 5, the tapered groove 14 opens into the bore space of the cylinder 5a, and the lubricating oil 4 accumulated in the oil reservoir 13 at the upper part of the cylinder is transferred to the cylinder 5a. Flows into the bore.

  In the compression stroke in which the piston 7 moves from the bottom dead center to the top dead center, the lubricating oil 4 held in the two annular grooves 15 of the piston 7 keeps the lubrication and sealing performance between the piston and the cylinder good. It will be.

  In the oil supply structure of the present embodiment, as shown in FIGS. 6 to 8, together with the tapered groove 14 as the oil supply portion, a part of the main shaft side end side surface of the cylinder 5 a is deleted, and the piston 7 is near the bottom dead center. A communication portion 14 a communicating with the upper annular groove 15 is formed. This ensures that the lubricating oil is taken into the annular groove 15 that is the lubricating oil holding portion.

  This operation will be described with reference to the schematic diagram of FIG. Reference numeral C1 is a clearance between the cylinder and the piston sliding portion, and is about 5 μm. Reference numeral C2 is a depth of the annular groove 15 and is about 50 μm. Lubricating oil that has flowed into the annular groove 15 from the tapered groove 14 serving as the lubricating oil supply part is communicated with the annular groove 15 so that the communicating part 14a can be connected to the annular groove 15 even when gas is present in the annular groove 15. It becomes easy to be discharged as a gas escape port.

  As a result, the vapor lock phenomenon in which the gas stays in the annular groove 15 and hinders the inflow of the lubricating oil can be prevented, and the lubricating oil 4 can be spread throughout the groove as shown by the arrows. The lubricating oil retention of the piston 7 can be improved.

  The communication portion 14a is formed at a position where the connecting rod 6 fitted to the eccentric shaft 8b can be introduced into the cylinder 5a. The connecting portion 14a is connected to the piston 7 at the small end of the connecting rod 6 to assemble the compression element 5. Is also used in combination. In the present embodiment, the tapered groove 14 is formed by cutting a part of the inner peripheral wall of the cylinder 5a as the lubricating oil supply portion. However, the present invention is not limited to this, and is not a tapered groove but a parallel groove or a cross-sectional cylinder. It may be a V-shaped cross section instead of a shape.

(Embodiment 2)
Next, a second embodiment of the present invention will be described with reference to FIGS. In the present embodiment, an oil supply hole structure that can be processed more simply is adopted instead of the tapered groove formed in a part of the inner peripheral surface of the cylinder in the shape of the lubricating oil supply portion. FIG. 10 is an enlarged cross-sectional view of a main part of a hermetic compressor according to the second embodiment of the present invention, and FIG. 11 is a perspective view showing positions of oil supply holes formed in the cylinder in FIG.

  In the present embodiment, an oil supply hole 30 penetrating the cylinder wall is formed from the oil reservoir portion 13 formed on the outer peripheral upper surface portion of the cylinder 5a. The position of the oil supply hole 30 is formed so as to communicate with the annular groove 15 on the upper side of the piston 7 when the piston 7 is positioned near the bottom dead center. Reference numeral 15 ′ in FIG. 11 indicates a groove width position in the vicinity of the bottom dead center of the annular groove 15 on the upper side of the piston 7 by a two-dot chain line, and shows a state of communicating with the oil supply hole 30.

  Also in this embodiment, the basic oil supply function between the piston and the cylinder bore is realized in the same manner as in the first embodiment. Since the lubricating oil supply unit is configured by simple drilling, the number of processing steps can be shortened and the cost of the compressor can be reduced.

  In the embodiment described in detail above, the formation of an oil film between the piston and the cylinder is ensured, the sealing performance is improved, and the compressor efficiency at the time of low speed operation in the rotation speed control compressor by the inverter having a large influence of leakage is improved. In addition, it is possible to provide a hermetic compressor that can improve the reliability of the compressor.

  Further, the system to which the hermetic compressor of the present invention is applied is not limited to a refrigerator, and can be applied to a system such as a room air conditioner or a refrigerator for refrigeration and air conditioning applications. Can be improved.

DESCRIPTION OF SYMBOLS 1 Airtight container 2 Electric element 2a Stator 2b Rotor 3 Compression element 4 Lubricating oil 5 Cylinder block 5a Cylinder 5b Frame part 5c Bearing part 6 Connecting rod 7 Piston 8 Crankshaft 8a Main shaft 8b Eccentric shaft 8ba Oil supply groove 8bb Lubricating oil radiation hole 8c Oil pump DESCRIPTION OF SYMBOLS 9 Balance weight 10 Cylinder head 11 Head cover 12 Compression chamber 13 Oil sump part 13a Partition wall 14 Tapered groove 14a Communication part 15 Annular groove 16 Suction pipe 17 Suction silencer 18 Discharge silencer 19 Discharge pipe 20 Discharge pipe 30 Oil supply hole 50 Sealing type compressor 60 Refrigerator 61 Refrigerator main body 62 Refrigerated room 63 Upper freezer room 64 Lower freezer room 65 Vegetable room 66 Cooler

Claims (7)

A compression element and an electric element housed in an airtight container are provided, the compression element has a piston and a cylinder, and a lower end portion of a crankshaft driven by the electric element is immersed in lubricating oil stored in the airtight container. The lubricating oil is raised by the centrifugal force of an oil pump provided at the lower end portion of the crankshaft, and the lubricating oil ejected from an oil supply hole of the eccentric shaft formed eccentrically at the upper portion of the crankshaft is supplied to the cylinder and the piston. In the hermetic compressor supplied during
A lubricating oil supply section provided in the cylinder; and a lubricating oil holding section provided in the piston. The lubricating oil holding section when the lubricating oil is supplied from the lubricating oil supply section to the lubricating oil holding section. A hermetic compressor, wherein the cylinder is provided with a degassing part that suppresses retention of refrigerant gas in the part. A compression element and an electric element housed in an airtight container are provided, the compression element has a piston and a cylinder, and a lower end portion of a crankshaft driven by the electric element is immersed in lubricating oil stored in the airtight container. The lubricating oil is raised by the centrifugal force of an oil pump provided at the lower end portion of the crankshaft, and the lubricating oil ejected from an oil supply hole of the eccentric shaft formed eccentrically at the upper portion of the crankshaft is supplied to the cylinder and the piston. In the hermetic compressor supplied during
The piston has an annular groove on the outer peripheral surface thereof, and two or more communicating portions are provided on the crankshaft side end surface of the cylinder, and the communicating portion is connected to the annular groove when the piston is located near the bottom dead center. A hermetic compressor that communicates with an inner periphery of a cylinder bore when the piston is located near top dead center.   The hermetic compression according to claim 1 or 2, wherein a partition wall constituting an oil reservoir is provided on the upper surface of the cylinder, and a bottom surface of the oil reservoir is inclined downward toward the crankshaft side. Machine.   2. The lubricating oil supply portion is a tapered groove formed in an inner wall of an upper cylinder on an end surface on the crankshaft side of the cylinder, and the gas venting portion is provided below the lubricating oil supply portion. The hermetic compressor as described.   3. The hermetic compressor according to claim 2, wherein the communication portion is provided on an inner wall of the upper cylinder on the crankshaft side end surface of the cylinder.   The hermetic compressor according to claim 1 or 2, wherein the hermetic compressor is driven by an inverter at a plurality of operating frequencies including an operating frequency equal to or lower than a power supply frequency. In a refrigerator comprising a hermetic compressor, and a cooler connected to the hermetic compressor and a refrigerant pipe,
The hermetic compressor includes a compression element and an electric element housed in a hermetic container, the compression element includes a piston and a cylinder, and a lower end portion of a crankshaft driven by the electric element is stored in the hermetic container. The lubrication oil is immersed in the lubrication oil, lifted by the centrifugal force of an oil pump provided at the lower end of the crankshaft, and ejected from an oil supply hole of the eccentric shaft formed eccentrically on the upper portion of the crankshaft Supplying oil between the cylinder and the piston;
The piston has an annular groove on the outer peripheral surface thereof, and two or more communicating portions are provided on the crankshaft side end surface of the cylinder, and the communicating portion is connected to the annular groove when the piston is located near the bottom dead center. A refrigerator that communicates with an inner periphery of a cylinder bore when the piston is located near top dead center.

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