JP2009275651A - Hermetic compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve reliability and efficiency by reducing the surface pressure of a piston sliding portion, and preventing uneven contact due to pinching, in a hermetic compressor equipped with a cantilever bearing. <P>SOLUTION: The hermetic compressor comprises a connecting rod 126 absorbing the tilting of an eccentric shaft portion 112 to an axis of a bearing portion 120 and having a large end hole tilting curved surface 128c tilted in a direction suppressing the tilting of a piston 123, thereby absorbing the tilting of the eccentric shaft portion 112 due to a clearance of the bearing portion 120 or the deformation of a shaft 110. Therefore, uneven contact due to pinching of the piston 123 sliding portion can be prevented, and the surface pressure of the sliding portion can be decreased, so that reliability and efficiency can be improved. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a hermetic compressor used in a refrigeration cycle such as a refrigerator-freezer.

  In recent years, with regard to hermetic compressors used in refrigeration apparatuses such as refrigerators and refrigerators, high efficiency, low noise, and high reliability for reducing power consumption are desired.

  Conventionally, as this type of hermetic compressor, there is one in which the method of supplying oil to the small end hole portion of the connecting rod is improved to improve efficiency and reliability (for example, see Patent Document 1).

  Hereinafter, the conventional hermetic compressor will be described with reference to the drawings.

  FIG. 15 is a longitudinal sectional view of a conventional hermetic compressor described in Patent Document 1, and FIG. 16 is a sectional view of an essential part of FIG. FIG. 17 is a cross-sectional view of a main part for explaining that a twist occurs between the piston and the compression chamber.

  As shown in FIGS. 15, 16, and 17, the hermetic container 1 accommodates an electric element 4 having a stator 2 and a rotor 3, and a compression element 5 driven by the electric element 4, Lubricating oil 6 is stored in the sealed container 1.

  The shaft 10 has a main shaft portion 11 to which the rotor 3 is fixed, and an eccentric shaft portion 12 formed eccentric to the main shaft portion 11, and the cylinder block 14 includes a substantially cylindrical compression chamber 15 and a bearing portion 20. Have.

  The piston 23 is inserted into the compression chamber 15 of the cylinder block 14 so as to be slidable back and forth, and the piston pin 25 is fixed.

  The connecting rod 26 includes a large end hole portion 28, a small end hole portion 29, and a rod portion 30. The eccentric shaft portion 12 is inserted into the large end hole portion 28, and the piston pin 25 is inserted into the small end hole portion 29. Thus, the eccentric shaft portion 12 and the piston pin 25 are connected.

  Further, when the piston pin 25 and the small end hole 29 come into contact with the inner wall of the small end hole 29 near the center in the axial direction of the small end hole 29, the upper end of the small end hole 29 in the vertical direction and A convex spherical portion 31 is formed so that a gap is formed at the lower end.

  An oil supply passage 35 is provided inside the shaft 10, and an oil distribution pipe 36 is inserted and fixed perpendicularly to the upper end of the oil supply passage 35. Further, the lower end portion 40 of the oil supply passage 35 opens into the lubricating oil 6.

  The operation of the hermetic compressor configured as described above will be described below.

  The rotor 3 of the electric element 4 rotates the shaft 10, and the rotational movement of the eccentric shaft portion 12 is transmitted to the piston 23 via the connecting rod 26 and the piston pin 25, so that the piston 23 reciprocates in the compression chamber 15. .

  Thereby, the refrigerant gas is sucked into the compression chamber 15 from the cooling system (not shown), compressed, and then discharged to the cooling system again.

  The lower end portion of the oil supply passage 35 is pumped by the rotation of the shaft 10, and the lubricating oil 6 at the bottom of the hermetic container 1 is pumped upward through the oil supply passage 35 by this pump action.

  The lubricating oil 6 reaching the upper part of the oil supply passage 35 is scattered from the upper part of the oil distribution pipe 36 into the hermetic container 1 by the centrifugal force in the horizontal circumferential direction, and a part of the lubricating oil 6 is supplied to the piston 23, the piston pin 25 and the like. Lubricate.

Further, since the inner wall of the small end hole 29 is a convex spherical portion 31, even if a force that squeezes the connecting rod 26 is generated, the contact portion of the spherical portion 31 is displaced, so that it is small from the piston pin 25. Local twisting with the end hole 29 can be prevented. Furthermore, a large amount of oil can be supplied to the sliding portion between the piston pin 25 and the small end hole portion 29, so that high reliability and high efficiency can be achieved.
JP 09-317644 A

  However, the above-described conventional configuration is insufficient to prevent twisting between the piston 23 and the compression chamber 15 that occurs when a compression load for compressing the refrigerant gas is applied. This will be described with reference to the cross-sectional view shown in FIG. As shown in FIG. 17, when a compression load F generated on the piston 23 in the compression stroke of the refrigerant gas acts on the eccentric shaft portion 12, there is a clearance between the main shaft portion 11 and the bearing portion 20. Is inclined by an angle Δγ with respect to the bearing portion 20, and the relative angle of the axial center between the compression chamber 15 and the bearing portion 20 also changes due to the deformation of the cylinder block 14. For this reason, as shown in the drawing, the axis of the piston 23 is inclined. In the conventional device described above, the inner wall of the small end hole 29 has a convex shape, so that the inclination of the piston 23 is suppressed. However, the twisting between the piston 23 and the compression chamber 15 cannot be prevented.

  Part of the sliding surface on which the piston 23 slides with the peripheral wall of the compression chamber 15 due to the occurrence of a twist between the piston 23 and the compression chamber 15, that is, a part of the edge of the upper end surface indicated by P in the figure The surface pressure increases locally. For this reason, even with the conventional hermetic compressor in which the inner wall surface of the small end hole 29 is convex, there is a problem to be solved that the wear of the piston 23 is accelerated and the sliding loss is increased. Was.

  The present invention has been made to solve the above-described problems, and its object is to prevent the occurrence of a twist between the piston and the compression chamber, thereby delaying the wear of the piston and reducing the sliding loss. Another object of the present invention is to provide a hermetic compressor that can achieve higher reliability and higher efficiency.

  In order to solve the above-described conventional problems, the hermetic compressor of the present invention includes an absorption mechanism that absorbs the inclination of the eccentric shaft portion with respect to the shaft center of the bearing portion and suppresses the inclination of the piston pin. The inclination of the eccentric shaft due to the bearing clearance and deformation due to compressive load in the bearing is absorbed by the slanting surface of the small end hole or large end hole of the connecting rod, and the piston sliding part is twisted. Prevents contact with each other.

  In the hermetic compressor of the present invention, the small end hole portion, the large end hole portion, and the sliding surface of each piston sliding portion are inclined, and the sliding surface of the connecting rod small end hole portion or large end hole portion is inclined. Since it can absorb by having, it can prevent the one-piece | unit contact by the twist of a piston sliding part, and can provide a highly reliable and highly efficient hermetic compressor.

  According to a first aspect of the present invention, the lubricating oil is stored in a sealed container and an electric element and a compression element driven by the electric element are accommodated, and the compression element includes a shaft having an eccentric shaft portion and a main shaft portion. , A bearing portion in which a cantilever bearing is formed by pivotally supporting the main shaft portion of the shaft, a cylinder block having a substantially cylindrical compression chamber, a piston reciprocating in the compression chamber, and a shaft on the piston A piston pin disposed so that its center is parallel to the eccentric shaft portion, and a small end hole that has a large end hole portion that pivotally supports the eccentric shaft portion at one end of the rod portion and pivotally supports the piston pin at the other end A connecting rod having a portion, and an absorption mechanism for absorbing the inclination of the eccentric shaft portion with respect to the shaft center of the bearing portion to suppress the inclination of the piston, and a small end hole portion or a large end hole of the connecting rod On at least one of the parts The absorption mechanism having an inclined curved surface that is inclined in a direction to suppress the inclination of the piston absorbs the inclination of the eccentric shaft portion due to the clearance of the bearing portion and the compressive load in the cantilever bearing. Since it is possible to prevent one-side contact due to twisting and to reduce the surface pressure of the sliding portion, it is possible to provide a highly reliable and highly efficient hermetic compressor.

  The invention according to claim 2 is the invention according to claim 1, wherein the inner diameter portion of the large end hole portion or the small end hole portion is at least an eccentric shaft portion with respect to the shaft center of the bearing portion when a compressive load is applied. It has an inclined curved surface that inclines in a direction that absorbs the inclination of the piston and suppresses the inclination of the piston. When a compressive load acts on the connecting rod or the eccentric shaft part and the eccentric shaft part inclines, the large end hole of the connecting rod Since the sliding surface of the part or small end hole has an inclined curved surface, it is possible to suppress the inclination and prevent the piston sliding part from twisting and reducing the surface pressure, so it is highly reliable and highly efficient. A hermetic compressor can be provided.

  The invention according to claim 3 is the invention according to claim 1, wherein the eccentric shaft portion or the outer peripheral portion of the piston pin has an inclination of the eccentric shaft portion with respect to the shaft center of the bearing portion at least when a compressive load is applied. It is equipped with an inclined curved surface that is inclined in a direction that suppresses the inclination of the piston, and when the eccentric shaft part or the axis of the piston pin is inclined due to a compressive load acting on the connecting rod or the eccentric shaft part. The sliding surface of the shaft or piston pin has an inclined curved surface, which suppresses the tilt of the sliding surface of the shaft center of the bearing and the eccentric shaft, prevents the piston sliding part from being squeezed and reduces the surface pressure. Therefore, it is possible to provide a highly reliable and highly efficient hermetic compressor.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a longitudinal sectional view of a hermetic compressor according to Embodiment 1 of the present invention, FIG. 2 is a sectional view of essential parts of FIG. 1 when a compressive load is not applied, and FIG. The principal part sectional drawing of FIG. 1 when the compressive load acts in embodiment is shown, FIG. 4 is sectional drawing of the connecting rod in the embodiment. In each drawing, the bearing gap is enlarged to make it easy to understand the inclination of each sliding portion.

  In FIGS. 1 to 4, an airtight container 101 contains an electric element 104 including a stator 102 and a rotor 103, and a compression element 105 driven by the electric element 104. The lubricating oil 106 is stored.

  The shaft 110 includes a main shaft portion 111 to which the rotor 103 is fixed, and an eccentric shaft portion 112 that is disposed above the main shaft portion 111 and is eccentric with respect to the main shaft portion 111. An oil supply passage 113 is provided, and a lower end portion of the oil supply passage 113 opens into the lubricating oil 106.

  The cylinder block 114 includes a substantially cylindrical compression chamber 115, and the bearing portion 120 forms a cantilever bearing by pivotally supporting the main shaft portion 111 of the shaft 110. An angle α formed by the first center line indicating the axis of the bearing portion 120 and the second center line indicating the axis of the compression chamber 115 is a right angle, that is, π / 2 rad.

  The piston 123 is inserted into the compression chamber 115 of the cylinder block 114 so as to be slidable in a reciprocating manner, and a piston pin 125 is fixed so that the shaft center is parallel to the eccentric shaft portion 112.

  The connecting rod 126 has a large end hole portion 128, a small end hole portion 129, and a rod portion 130. The eccentric shaft portion 112 is inserted into the large end hole portion 128, and the piston pin 125 is inserted into the small end hole portion 129. Thus, the eccentric shaft portion 112 and the piston pin 125 are connected.

  As shown in FIG. 4, the large end hole portion 128 is a taper-shaped large end hole inclination having an inner diameter D2 of the bearing side 128b larger than the inner diameter D1 of the non-bearing side 128a as an absorption mechanism 145 that suppresses the inclination of the piston 123. The large end hole inclined curved surface 128c is inclined such that the distance from the small end hole curved surface 129a is smaller in the bearing side distance L2 than in the counter bearing side distance L1.

  The refrigerant gas used in the hermetic compressor is R134a having a zero ozone depletion coefficient, or a hydrocarbon refrigerant that is a natural refrigerant having a low global warming coefficient represented by R600a. Combined with high lubricating oil.

  The operation and action of the hermetic compressor configured as described above will be described below.

  The rotor 103 of the electric element 104 rotates the shaft 110, and the rotational movement of the eccentric shaft portion 112 is transmitted to the piston 123 via the connecting rod 126 and the piston pin 125, so that the piston 123 reciprocates in the compression chamber 115. . By the reciprocating motion of the piston 123, the refrigerant gas is sucked into the compression chamber 115 from the cooling system (not shown), compressed, and then discharged to the cooling system again.

  The lower end portion of the oil supply passage 113 performs a pumping action by the rotation of the shaft 110, and by this pumping action, the lubricating oil 106 at the bottom of the sealed container 101 is pumped upward through the oil supply passageway 113, and each sliding Supplied to the department.

  A compression load generated when the refrigerant gas is compressed is pivotally supported by a bearing portion 120 having a cantilever support configuration via a piston 123, a connecting rod 126, and a shaft 110.

  At this time, since there is a clearance between the bearing portion 120 and the main shaft portion 111, the main shaft portion 111 is inclined by γrad with respect to the axis of the bearing portion 120 as shown in FIG. Further, since the bearing portion 120 and the eccentric shaft portion 112 are deformed by a compressive load, the eccentric shaft portion 112 is inclined by Δγ with respect to the axis of the eccentric shaft portion 112. Therefore, the sliding surface on the piston 123 side where the compression load acts on the inner diameter portion of the large end hole portion 128 of the connecting rod 126 is inclined by γ + Δγ along the inclination of the eccentric shaft portion 112.

  However, in the present invention, as shown in FIG. 4, the large end hole inclined curved surface 128c is inclined so that the distance from the small end hole curved surface 129a is smaller in the bearing side distance L2 than in the non-bearing side distance L1. Therefore, the inclination of the central axis of the connecting rod 126 in the vertical direction can be suppressed and absorbed, and the parallelism with the central axis of the compression chamber 115 can be maintained. For this reason, there is no deviation between the central axis of the piston 123 and the central axis of the compression chamber 115. Therefore, although the eccentric shaft portion 112 is inclined by γ + Δγ, the angle between the central axis of the piston 123 and the central axis of the bearing portion 120 can be maintained at π / 2 rad.

  Therefore, the piston 123 and the compression chamber 115 can be prevented from being twisted, the wear of the piston 123 is delayed, the sliding loss is reduced, and further higher reliability and higher efficiency can be achieved.

  In the present embodiment, the connecting rod 126 has a shape having the large end hole inclined curved surface 128c in the large end hole portion 128, but as shown in FIG. 5, the connecting rod 126 is inclined toward the compression load receiving side of the large end hole inner diameter portion. The piston 123 can be prevented from being twisted even if it has a shape having 128d, a shape having inclined curved surfaces 129b and 129c in the small end hole portions as shown in FIGS. Can be obtained.

  Further, by making the shape of the inclined curved surface provided in the large end hole portion 128 or the small end hole portion 129 into a tapered shape, the sliding area of the large end hole portion 128 or the small end hole portion 129 is reduced, and the sliding loss is reduced. The effect that it can reduce can be acquired.

(Embodiment 2)
FIG. 8 is a longitudinal sectional view of the hermetic compressor according to the second embodiment of the present invention, FIG. 9 is a sectional view of the main part of FIG. 8 when the compressive load does not act in the same embodiment, and FIG. It is principal part sectional drawing of FIG. 8 when the compressive load acts in embodiment. FIG. 11 is a cross-sectional view of the eccentric shaft portion in the same embodiment. In each drawing, the bearing gap is enlarged to make it easy to understand the inclination of each sliding portion.

  8 to 11, the sealed container 201 accommodates an electric element 204 having a stator 202 and a rotor 203, and a compression element 205 driven by the electric element 204, and a bottom portion in the sealed container 201. The lubricating oil 206 is stored in the tank.

  The shaft 210 includes a main shaft portion 211 to which the rotor 203 is fixed, and an eccentric shaft portion 212 that is disposed above the main shaft portion 211 and is eccentric with respect to the main shaft portion 211. An oil supply passage 213 is provided, and a lower end portion of the oil supply passage 213 opens into the lubricating oil 206.

  The cylinder block 214 includes a substantially cylindrical compression chamber 215, and the bearing portion 220 forms a cantilever bearing by supporting the main shaft portion 211 of the shaft 210. The angle α formed by the first center line indicating the axis of the bearing 220 and the second center line indicating the axis of the compression chamber 215 is a right angle, that is, π / 2 rad.

  The piston 223 is inserted into the compression chamber 215 of the cylinder block 214 so as to be slidable back and forth, and the piston pin 225 is fixed so that the shaft center is parallel to the eccentric shaft portion 212.

  The connecting rod 226 has a large end hole portion 228, a small end hole portion 229, and a rod portion 230. The eccentric shaft portion 212 is inserted into the large end hole portion 228, and the piston pin 225 is inserted into the small end hole portion 229. Thus, the eccentric shaft portion 212 and the piston pin 225 are connected.

  As shown in FIG. 11, the eccentric shaft portion 212 serves as an absorption mechanism 245 that suppresses the inclination of the piston 223, and has a tapered eccentric shaft inclination in which the outer diameter d2 on the non-bearing side 212b is larger than the outer diameter d1 on the bearing side 212a. It has a curved surface 212c.

  The refrigerant gas used in the hermetic compressor is R134a having a zero ozone depletion coefficient, or a hydrocarbon refrigerant that is a natural refrigerant having a low global warming coefficient represented by R600a. Combined with high lubricating oil.

  The operation of the hermetic compressor configured as described above will be described below.

  The rotor 203 of the electric element 204 rotates the shaft 210, and the rotational movement of the eccentric shaft portion 212 is transmitted to the piston 223 via the connecting rod 226 and the piston pin 225, so that the piston 223 reciprocates in the compression chamber 215. . The reciprocating motion of the piston 223 causes the refrigerant gas to be sucked into the compression chamber 215 from the cooling system (not shown), compressed, and then discharged to the cooling system again.

  The lower end portion of the oil supply passage 213 is pumped by the rotation of the shaft 210, and by this pump action, the lubricating oil 206 at the bottom of the sealed container 201 is pumped upward via the oil supply passage 213, and each slide Supplied to the department.

  A compression load generated when the refrigerant gas is compressed is pivotally supported by a bearing portion 220 having a cantilever support configuration via a piston 223, a connecting rod 226, and a shaft 210.

  At this time, since there is a clearance between the bearing portion 220 and the main shaft portion 211, the main shaft portion 211 is inclined by γrad with respect to the shaft center of the bearing portion 220 as shown in FIG. Further, since the bearing portion 220 and the eccentric shaft portion 212 are further deformed by a compressive load, the central axis of the eccentric shaft portion 212 is further inclined by Δγ.

  However, in the present invention, as shown in FIG. 11, the eccentric shaft inclined curved surface 212c has a tapered shape in which the outer diameter d2 on the non-bearing side 212b is larger than the outer diameter d1 on the bearing side 212a. It is possible to suppress and absorb the inclination of the vertical direction and maintain the parallelism with the central axis of the compression chamber 215. Therefore, there is no deviation between the central axis of the piston 223 and the central axis of the compression chamber 215. Therefore, although the central axis of the eccentric shaft portion 212 is inclined by γ + Δγ, the angle between the central axis of the piston 223 and the central axis of the bearing portion 220 can be maintained as π / 2 rad.

  Accordingly, the piston 223 and the compression chamber 215 can be prevented from being twisted, the wear of the piston 223 is delayed, the sliding loss is reduced, and further higher reliability and higher efficiency can be achieved.

  In the present embodiment, the eccentric shaft portion 212 has a shape having an eccentric shaft inclined curved surface 212c. However, as shown in FIG. 12, the eccentric shaft outer diameter portion has a shape having an inclination 212d on the compression load receiving side. As shown in FIGS. 13 and 14, even if the piston pin 225d has a shape having the inclined curved surfaces 225f and 225g or a combination thereof, the piston 223 can be prevented from being twisted, and the same effect can be obtained.

  Further, by making the shape of the inclined curved surface provided in the eccentric shaft portion 212 or the piston pin 225d into a tapered shape, the sliding area of the eccentric shaft portion 212 or the piston pin 225 is reduced, and the sliding loss can be reduced. Can be obtained.

  As described above, the hermetic compressor according to the present invention can prevent the piston sliding portion from being twisted due to the inclination of the eccentric shaft portion, so that high reliability and high efficiency are achieved by reducing piston wear. Therefore, it can be applied to air-conditioning and vending machine hermetic compressors in addition to refrigerator-freezers.

1 is a longitudinal sectional view of a hermetic compressor according to Embodiment 1 of the present invention. Sectional drawing of the principal part of FIG. 1 when the compressive load does not act in the same embodiment Sectional drawing of the principal part of FIG. 1 when the compressive load acts in the embodiment Cross-sectional view of the connecting rod in the same embodiment Connecting rod cross-sectional view when the large end hole in the same embodiment has an inclination Cross-sectional view of connecting rod having a tapered small end hole in the same embodiment Connecting rod cross-sectional view when the small end hole portion in the same embodiment has an inclination Vertical sectional view of a hermetic compressor according to Embodiment 2 of the present invention Cross-sectional view of the main part of FIG. 8 when the compressive load does not act in the same embodiment Cross-sectional view of the main part of FIG. 8 when the compressive load acts in the same embodiment Sectional drawing of the eccentric shaft part in the embodiment Cross-sectional view of main parts when the eccentric shaft has an inclination in the same embodiment Cross-sectional view of the main part of the taper shape of the piston pin in the same embodiment Cross-sectional view of main parts when the piston pin has an inclination in the same embodiment Vertical section of a conventional hermetic compressor Cross-sectional view of the main part of FIG. Cross-sectional view of the main part for explaining that the piston is twisted

Explanation of symbols

101, 201 Airtight container 104, 204 Electric element 105, 205 Compression element 106, 206 Lubricating oil 110, 210 Shaft 111, 211 Main shaft part 112, 212 Eccentric shaft part 114, 214 Cylinder block 115, 215 Compression chamber 120, 220 Bearing part 123,223 Piston 125,225 Piston pin 126,226 Connecting rod 128,228 Large end hole 128c Large end hole inclined curved surface 129,229 Small end hole 130,230 Rod part 145,245 Absorption mechanism

Claims (3)

  Lubricating oil is stored in an airtight container, and an electric element and a compression element driven by the electric element are accommodated. The compression element has a shaft having an eccentric shaft portion and a main shaft portion, and the main shaft portion of the shaft is pivoted. A bearing part that forms a cantilever bearing by supporting, a cylinder block that includes a substantially cylindrical compression chamber, a piston that reciprocates in the compression chamber, and an axis that is parallel to the eccentric shaft portion of the piston. A piston pin disposed so as to comprise a connecting rod having a large end hole portion that pivotally supports the eccentric shaft portion at one end of the rod portion and a small end hole portion that pivotally supports the piston pin at the other end, A hermetic compressor comprising an absorption mechanism that absorbs an inclination of the eccentric shaft portion with respect to an axis of the bearing portion and suppresses an inclination of the piston.   The inner diameter portion of the large end hole portion or the small end hole portion is an inclined curved surface inclined in a direction to absorb the inclination of the eccentric shaft portion with respect to the shaft center of the bearing portion and suppress the inclination of the piston at least when a compressive load is applied. The hermetic compressor according to claim 1, comprising:   The outer peripheral portion of the eccentric shaft portion or the piston pin is provided with an inclined curved surface inclined in a direction that absorbs the inclination of the eccentric shaft portion with respect to the shaft center of the bearing portion and suppresses the inclination of the piston at least when a compressive load is applied. The hermetic compressor according to claim 1.