JP2013096326A - Hermetic compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hermetic compressor in which a local metallic contact between the large end aperture section of a connecting means and an eccentric shaft resulting from a tilt of the shaft is prevented from occurring, and reliability is improved.SOLUTION: The local metallic contact between the eccentric shaft 125 in a shaft 119 and the large end aperture section 145 of the connecting means 143 can be prevented so as to suppress wear caused by the local metallic contact, because the tilt of the eccentric shaft 125 in the shaft 119 caused by the compressing load taking place in a compression stroke can be absorbed by allowing a thinned section 180 provided to the connecting means 143 to be warped, as at least a part of the end of the large end aperture section 145 in the connecting means 143 has the thinned section 180 thinner than the thickness in the radius direction at the central position in the axial direction of the large end aperture section 145.

Description

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

  As a conventional hermetic compressor, there is one having a connecting means having a large end hole, a small end hole, and a rod for connecting the eccentric shaft of the piston and the shaft (see, for example, Patent Document 1). ).

  Further, as a means for suppressing wear caused by local metal contact between the large end hole of the connecting means and the shaft eccentric shaft, which is a problem of the conventional hermetic compressor, a spherical bearing is provided in the large end hole of the connecting means. Some are provided (for example, see Patent Document 2).

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

  FIG. 8 is a longitudinal sectional view of a conventional hermetic compressor described in Patent Document 1, and FIG. 9 is an enlarged sectional view of a main part of the compressor.

  As shown in FIGS. 8 and 9, lubricating oil 3 is stored at the bottom of the sealed container 1, and the compressor body 5 is elastically supported by the suspension container 7 with respect to the sealed container 1. .

  The compressor main body 5 includes an electric element 11 and a compression element 17 disposed above the electric element 11. The electric element 11 includes a stator 13 and a rotor 15.

  The shaft 19 of the compression element 17 includes a main shaft 23, a flange portion 21 provided at the upper end of the main shaft 23, and an eccentric shaft 25 extending from the upper surface of the flange portion 21, and the main shaft 23 is a bearing for the cylinder block 29. The rotor 15 is fixed to the shaft 31 so as to be freely rotatable. And it is the structure of the cantilever bearing which supports the main axis | shaft 23 arrange | positioned under the eccentric shaft 25 with the bearing 31 with respect to the eccentric shaft 25 to which a load acts.

  Further, the shaft 19 includes an oil supply mechanism 27 including a spiral groove provided on the surface of the main shaft 23.

  The piston 33 is reciprocally inserted into a cylinder 37 having a substantially cylindrical inner surface formed in the cylinder block 29.

  The cylinder 37 and the piston 33 form a compression chamber 41 together with a valve plate 39 attached to the opening end surface of the cylinder 37. Further, the cylinder head 53 is fixed so as to cover the valve plate 39 and cover it.

  The suction muffler 55 is molded from a resin such as PBT, forms a silencing space inside, and is attached to the cylinder head 53.

The connecting means 43 includes a large end hole 45, a small end hole 47, and a rod part 49. The eccentric shaft 25 is inserted into the large end hole 45, and the piston 33 is connected to the small end hole 47. The fitted piston pin 35 is inserted. With this configuration, the connecting means 43 is connected to the eccentric shaft 25 and the piston 33.
Are connected.

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

  When the electric element 11 is energized, the rotor 15 rotates together with the main shaft 23 due to the rotating magnetic field generated in the stator 13. The eccentric shaft 25 moves eccentrically by the rotation of the main shaft 23, and the eccentric movement of the eccentric shaft 25 is transmitted to the piston 33 through the connecting means 43, and the piston 33 reciprocates in the cylinder 37.

  The refrigerant returned from the refrigeration cycle (not shown) outside the hermetic container 1 is introduced into the compression chamber 41 via the suction muffler 55, and is compressed by the piston 33 in the compression chamber 41, and the compressed refrigerant is sealed. It is sent from the container 1 to the refrigeration cycle.

  Next, the flow of the lubricating oil 3 will be described.

  The lower end of the shaft 19 is immersed in the lubricating oil 3, and as the shaft 19 rotates, the lubricating oil 3 is supplied to each part of the compression element 17 by the oil supply mechanism 27 of the shaft 19 to lubricate the sliding part.

  10 is a longitudinal sectional view of a conventional hermetic compressor described in Patent Document 2, FIG. 11 is a longitudinal sectional view of a connecting means of the compressor, and FIG. 12 is a compression load in the compressor. It is principal part sectional drawing at the time.

  As shown in FIGS. 10 and 11, the connecting means 43 has a large end hole portion 45, a small end hole portion 47, and a rod portion 49. The inner surface of the large end hole portion 45 of the connecting means 43 is processed into a spherical surface, and a journal type spherical bearing 51 having a spherical surface portion 52 is fitted into the inner surface. The eccentric shaft 25 is inserted into the cylindrical hole 57 of the spherical bearing 51, the small end hole portion 47 is fitted into the piston 33, and the piston pin 35 is inserted, whereby the connecting means 43 is connected to the eccentric shaft 25 and the piston 33. Are connected.

JP-A-60-125785 JP-A-3-153912

  However, in the configuration described in Patent Document 1, when a compression load is applied to the piston 33 as the refrigerant is compressed, the load acts on the eccentric shaft 25 via the connecting means 43, so that the gap between the main shaft 23 and the bearing 31 is not affected. A slight tilt in the range is inevitable, and the eccentric shaft 25 is similarly tilted.

  Therefore, the gap between the eccentric shaft 25 and the inner surface of the large end hole 45 of the connecting means 43 is partially reduced, and the oil film is locally thinned. As a result, when the compressive load becomes large as in overload operation, local metal contact occurs at the thin portion of the oil film of the eccentric shaft 25 and the connecting means 43, and there is a problem that wear tends to occur. It was.

On the other hand, the configuration described in Patent Document 2 is a cantilever bearing configuration as shown in FIG. 12, and is slightly inclined in the range of the gap between the main shaft 23 and the bearing 31 when a compression load F is applied to the piston 33. Inevitably, the eccentric shaft 25 is similarly inclined. However, the inner surface of the large end hole portion 45 is spherically processed, and is inclined in an arbitrary direction following the inclination of the eccentric shaft 25 by the spherical bearing 51 provided in the large end hole portion 45 of the connecting means 43. It is a configuration.

  Thereby, the structure of patent document 2 suppresses generation | occurrence | production of the local metal contact of the eccentric shaft 25 and the large end hole part 45 of the connection means 43 by the inclination of the eccentric shaft 25, and obtains the high reliability which suppressed wear. be able to.

  On the other hand, in the configuration of Patent Document 2, in order to suppress wear due to local metal contact between the eccentric shaft 25 of the shaft 19 and the large end hole 45 of the connecting means 43 due to a compressive load, the large end of the connecting means 43 is arranged. Since the spherical bearing 51 is disposed inside the hole 45, the number of parts increases, the structure of the large end hole 45 becomes complicated, and the weight of the connecting means 43 increases. Therefore, the centrifugal force accompanying the eccentric motion of the eccentric shaft 25 of the shaft 19 increases. As a result, when the compressive load becomes large as in overload operation, the load applied to the large end hole 45 increases and wears even if local metal contact between the shaft 19 and the large end hole 45 is suppressed. There was a problem that could occur.

  The present invention solves the above-described conventional problems, and does not increase the number of parts by a simple mechanism so as not to increase the load applied to the large end hole 45 of the connecting means 43 due to an increase in weight. An object of the present invention is to provide a hermetic compressor in which wear due to local metal contact of the large end hole 45 is suppressed.

  In order to solve the above-described conventional problems, the hermetic compressor of the present invention has a radial thickness at a central position in the axial direction of the large end hole at least at a part of the end of the large end hole of the connecting means. A thinner thin part is provided.

  With this configuration, the inclination of the eccentric shaft of the shaft due to the compressive load generated during the compression stroke can be absorbed by the bending of the thin wall portion provided in the coupling means, so the gap between the eccentric shaft of the shaft and the large end hole of the coupling means It is possible to suppress wear due to the occurrence of local metal contact. As a result, a simple mechanism does not increase the number of parts and weight, and does not increase the load applied to the large end hole of the connecting means, thereby suppressing wear of the eccentric shaft of the shaft and the large end hole of the connecting means. Can do.

  Since the hermetic compressor of the present invention can suppress the occurrence of wear due to local metal contact of the sliding portion, it is possible to provide a highly reliable hermetic compressor.

1 is a longitudinal sectional view of a hermetic compressor according to Embodiment 1 of the present invention. Longitudinal sectional view of connecting means of hermetic compressor in the first embodiment Sectional drawing of the principal part when the compression load of the hermetic compressor in Embodiment 1 acts Vertical sectional view of a hermetic compressor according to Embodiment 2 of the present invention The longitudinal cross-sectional view of the connection means of the hermetic compressor in Embodiment 2 The top view of the connection means of the hermetic compressor in the second embodiment Sectional drawing of the principal part when the compression load of the hermetic compressor in Embodiment 2 acts A longitudinal sectional view of a hermetic compressor showing a conventional example Main section enlarged sectional view of the same hermetic compressor Vertical sectional view of a hermetic compressor showing a different conventional example Longitudinal sectional view of connecting means of the hermetic compressor Cross-sectional view of main parts when compressive load is applied in the same hermetic compressor

  According to a first aspect of the present invention, the lubricating oil is stored in a sealed container, and an electric element including a stator and a rotor, and a compression element disposed above the electric element are accommodated, and the compression element is A cylinder block including a shaft having a main shaft, an eccentric shaft, and a flange portion to which a rotor is fixed, a cylinder and a bearing that supports the main shaft of the shaft, and a reciprocating motion inserted in the cylinder. And a connecting means for connecting the piston and the eccentric shaft, and an end of the large end hole portion of the connecting means. A thin part thinner than the radial thickness of the axial center position of the large end hole is formed on at least a part of the part.

  As a result, the inclination of the eccentric shaft of the shaft due to the compressive load generated during the compression stroke can be absorbed by the deflection of the thin wall portion provided in the connecting means, so the gap between the eccentric shaft of the shaft and the large end hole of the connecting means It is possible to suppress wear due to the occurrence of local metal contact. Therefore, since the load applied to the large end hole of the connecting means is not increased by a simple mechanism without increasing the number of parts and weight, it is possible to suppress wear of the eccentric shaft of the shaft and the large end hole of the connecting means. Therefore, the reliability can be improved.

  According to a second invention, in the first invention, the thin portion is provided over the entire circumference of the end portion of the large end hole portion of the connecting means.

  As a result, the inclination of the eccentric shaft due to the compressive load generated during the compression stroke can be absorbed in all directions, and wear due to local metal contact between the eccentric shaft of the shaft and the large end hole can be suppressed. Can be improved.

  According to a third invention, in the first or second invention, the axial length of the thin portion is set larger than the radial thickness of the thin portion.

  As a result, the strength of the thin portion can be intentionally weakened, and the thin portion of the connecting means can be structurally easily bent. As a result, even when the compression load generated during the compression stroke is small and the inclination of the eccentric shaft of the shaft is small, the thin wall portion can be bent and the inclination of the eccentric shaft can be absorbed. Therefore, wear due to local metal contact between the eccentric shaft of the shaft and the large end hole of the connecting means can be suppressed, and the reliability can be further improved.

  According to a fourth invention, in any one of the first to third inventions, a groove portion and an outer wall portion are provided on an outer peripheral side of the thin portion, and from a vertical center position of the large end hole portion to an end portion of the outer wall portion. Is made longer than the length from the vertical center position of the large end hole to the end of the thin portion.

  As a result, the lubricating oil can be stored in the groove provided on the outer periphery of the thin wall portion, and the height of the thin wall portion is lower than the outer wall portion. Can be supplied to the inner surface of the large end hole, and a sufficient oil film can be formed between the large end hole and the shaft eccentric shaft. As a result, metal contact between the eccentric shaft of the shaft and the large end hole of the connecting means can be suppressed, and wear can be suppressed to further improve reliability.

  According to a fifth invention, in any one of the first to fourth inventions, a part of the thin part is provided with a dividing groove that connects an outer peripheral surface of the thin part and an inner surface of the large end hole part. .

According to such a configuration, the thin portion is divided by the dividing groove, whereby the rigidity of the thin portion is lowered and the thin portion is easily bent. As a result, even when the compression load generated during the compression stroke is increased as in the overload operation and the inclination of the shaft is increased, the inclination of the eccentric shaft can be absorbed by the thin portion. Therefore, wear due to local metal contact between the eccentric shaft of the shaft and the large end hole portion of the connecting means can be suppressed, and the reliability can be further improved. In addition, when the end surface of the large end hole portion of the connecting means has a groove portion, the lubricating oil accumulated in the groove portion can be efficiently supplied to the inner surface of the large end hole portion, and the gap between the large end hole portion and the eccentric shaft of the shaft. A sufficient oil film can be formed. Thereby, generation | occurrence | production of the metal contact of the eccentric shaft of a shaft and the large end hole part of a connection means can be suppressed, and wear can be suppressed and reliability can be improved further.

  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 longitudinal sectional view of the connecting means in the first embodiment. FIG. 3 is a cross-sectional view of the main part when the compressive load acts in the first embodiment.

  As shown in FIG. 1, lubricating oil 103 is stored at the bottom of the sealed container 101, and the compressor body 105 is elastically supported by the suspension container 107 with respect to the sealed container 101.

  The compressor main body 105 includes an electric element 111 and a compression element 117 disposed above the electric element 111. The electric element 111 includes a stator 113 and a rotor 115.

  The shaft 119 of the compression element 117 includes a main shaft 123, a flange portion 121 provided at the upper end of the main shaft 123, and an eccentric shaft 125 extending from the upper surface of the flange portion 121, and the main shaft 123 is a bearing 131 of the cylinder block 129. And the rotor 115 is fixed. And it has the structure of the cantilever bearing supported with the main axis | shaft 123 and the bearing 131 which are arrange | positioned under the eccentric shaft 125 with respect to the eccentric shaft 125 to which a load acts.

  The shaft 119 includes an oil supply mechanism 127 including a spiral groove provided on the surface of the main shaft 123.

  The piston 133 is reciprocally inserted into a cylinder 137 having a substantially cylindrical inner surface formed in the cylinder block 129.

  The cylinder 137 and the piston 133 form a compression chamber 141 together with the valve plate 139 attached to the opening end surface of the cylinder 137. Further, a cylinder head 153 is fixed so as to cover the valve plate 139 and cover it.

  The suction muffler 155 is molded from a resin such as PBT, forms a silencing space inside, and is attached to the cylinder head 153.

  The connecting means 143 has a large end hole portion 145, a small end hole portion 147, and a rod portion 149. The eccentric shaft 125 is inserted into the large end hole portion 145, and the piston 133 is fitted into the small end hole portion 147. By inserting the formed piston pin 135, the eccentric shaft 125 and the piston 133 are connected.

In the first embodiment, the difference from the conventional hermetic compressor is that the center position in the axial direction of the large end hole 145 is located at the end of the large end hole 145 of the connecting means 143 as shown in FIG. The thin-walled portion 180 is thinner than the radial thickness, the axial length of the thin-walled portion 180 is H1, the radial thickness at the vertical center position of the large end hole 145 is T1, and the thin-walled portion at the end 180 radial thickness T
In the case of 2, the relationship of T1> T2 and H1> T2 is established.

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

  When the electric element 111 is energized, the rotor 115 rotates together with the main shaft 123 by the rotating magnetic field generated in the stator 113. Due to the rotation of the main shaft 123, the eccentric shaft 125 moves eccentrically, and the eccentric movement of the eccentric shaft 125 is transmitted to the piston 133 via the connecting means 143, and the piston 133 reciprocates in the cylinder 137.

  The refrigerant returned from the refrigeration cycle (not shown) outside the hermetic container 101 is introduced into the compression chamber 141 through the suction muffler 155, and is compressed by the piston 133 in the compression chamber 141. It is sent from the sealed container 101 to the refrigeration cycle.

  Next, the flow of the lubricating oil 103 will be described. The lower end of the shaft 119 is immersed in the lubricating oil 103. When the shaft 119 rotates, the lubricating oil 103 is supplied to each part of the compression element 117 by the oil supply mechanism 127 of the shaft 119 to lubricate the sliding part. Do.

  Next, the operation of the thin portion 180 provided in the connecting means 143 will be described. As shown in FIG. 3, in the hermetic compressor, the compression load F generated in the piston 133 during the compression stroke of the refrigerant gas acts on the eccentric shaft 125 via the connecting means 143. When the compressive load F acts on the eccentric shaft 125, there is a clearance between the main shaft 123 and the bearing 131, so the shaft 119 is inclined within the clearance range. If the shaft center of the main shaft 123 is tilted by the angle γ as shown in FIG. 3 with respect to the shaft center of the bearing 131, the eccentric shaft 125 is similarly tilted by the angle γ. As a result, the lower end gap b is smaller than the gap a between the upper end of the large end hole 145 and the eccentric shaft 125, and the oil film is thin.

  However, since the oil film pressure is large at the portion where the oil film is thin and the thin portion 180 can be bent to absorb the inclination, the local metal between the eccentric shaft 125 of the shaft 119 and the large end hole portion 145 of the connecting means 143. Wear due to contact can be suppressed. Thereby, wear due to local metal contact between the eccentric shaft 125 of the shaft 119 and the large end hole 145 of the connecting means 143 can be suppressed by a simple mechanism without increasing the number of parts, thereby improving reliability. Can do.

  Further, by forming the thin portion 180 on the entire circumference of the end portion of the large end hole portion 145 of the connecting means 143, the inclination of the eccentric shaft 125 of the shaft 119 due to the compressive load applied to the piston 133 during the compression stroke is all directions. Since the wear due to the occurrence of local metal contact between the eccentric shaft 125 of the shaft 119 and the large end hole portion 145 of the connecting means 143 is suppressed, the reliability can be further improved.

  Further, as shown in FIG. 2, the axial length of the thin portion 180 of the connecting means 143 is H1, the radial thickness of the vertical center position of the large end hole portion 145 is T1, and the thin portion 180 of the end portion is When the thickness in the radial direction is T2, the relationship of T1> T2 and H1> T2 is established, so that the thin portion 180 of the connecting means 143 is easily bent even with a small load. Therefore, even when the compression load generated during the compression stroke is small and the inclination of the eccentric shaft 125 of the shaft 119 is small, the thin portion 180 can be bent. Thereby, the inclination of the eccentric shaft 125 can be absorbed, and wear due to local metal contact between the eccentric shaft 125 of the shaft 119 and the large end hole portion 145 of the connecting means 143 can be suppressed, so that the reliability can be further improved. .

Specifically, when the outer diameter of the piston 133 is 20 mm, the distance by which the eccentric shaft 125 of the shaft 121 tilts due to the compressive load generated under the operating conditions used in the refrigerator, that is, the difference between a and b is 3 μm at the maximum. Then, when H1 which is the axial length of the thin portion 180 provided at the end of the large end hole portion 145 of the connecting means 143 is 2 mm and T2 which is the radial thickness is 1 mm, the deformation due to the load is 3 μm. The thin portion 180 of the large end hole portion 145 of the connecting means 143 is deformed according to the inclination of the eccentric shaft 125. As a result, the thin-walled portion 180 of the large end hole portion 145 undergoes substantially the same deformation with respect to the inclination of the eccentric shaft 125, so that local metal contact can be prevented from occurring.

  In the first embodiment, the thin-walled portion 180 at the end is provided on the entire circumference, but the same effect can be obtained by providing it on a part where the load increases.

(Embodiment 2)
FIG. 4 is a longitudinal sectional view of a hermetic compressor according to Embodiment 2 of the present invention. FIG. 5 is a longitudinal sectional view of the connecting means in the second embodiment. FIG. 6 is a top view of the connecting means in the second embodiment. FIG. 7 is a cross-sectional view of the main part when the compressive load acts in the second embodiment.

  As shown in FIG. 4, lubricating oil 203 is stored at the bottom of the sealed container 201, and the compressor body 205 is elastically supported by the suspension container 207 with respect to the sealed container 201.

  The compressor main body 205 includes an electric element 211 and a compression element 217 disposed above the electric element 211. The electric element 211 includes a stator 213 and a rotor 215.

  The shaft 219 of the compression element 217 includes a main shaft 223, a flange portion 221 provided at the upper end of the main shaft 223, and an eccentric shaft 225 extending from the upper surface of the flange portion 221, and the main shaft 223 is a bearing 231 of the cylinder block 229. And a rotor 215 is fixed. And it is the structure of the cantilever bearing supported with the main axis | shaft 223 arrange | positioned under the eccentric shaft 225 and the bearing 231 with respect to the eccentric shaft 225 where a load acts.

  The shaft 219 includes an oil supply mechanism 227 including a spiral groove provided on the surface of the main shaft 223.

  The piston 233 is reciprocally inserted into a cylinder 237 having a substantially cylindrical inner surface formed in the cylinder block 229.

  The cylinder 237 and the piston 233 form a compression chamber 241 together with the valve plate 239 attached to the open end surface of the cylinder 237. Further, a cylinder head 253 is fixed so as to cover the valve plate 239 and cover it.

  The suction muffler 255 is molded from a resin such as PBT, forms a silencing space inside, and is attached to the cylinder head 253.

  The connecting means 243 has a large end hole 245, a small end hole 247, and a rod 249. An eccentric shaft 225 is inserted into the large end hole 245, and the piston 233 is fitted into the small end hole 247. By inserting the piston pin 235, the eccentric shaft 225 and the piston 233 are connected.

The second embodiment is different from the conventional hermetic compressor in that the end of the large end hole 245 of the connecting means 243 is arranged in the axial direction of the large end hole 245 as shown in FIGS. It has a thin part 280 thinner than the radial thickness of the center position, the axial length of the thin part 280 is H1, the radial thickness of the vertical center position of the large end hole 245 is T1, and the end part When the thickness of the thin portion 280 in the radial direction is T2, the relationship of T1> T2 and H1> T2 is established.

  Further, a groove 284 and an outer wall 282 are provided on the outer peripheral side of the thin portion 280, and the length from the vertical center position of the large end hole 245 to the end of the thin portion 280 is H2, and the large end hole 245 is. When the length from the vertical center position to the end of the outer wall portion 282 is H3, the relationship of H3> H2 is established. Furthermore, a part of the thin part 280 is provided with a dividing groove 286 that connects the outer peripheral surface of the thin part 280 and the inner surface of the large end hole part 245.

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

  When the electric element 211 is energized, the rotor 215 rotates together with the main shaft 223 by the rotating magnetic field generated in the stator 213. Due to the rotation of the main shaft 223, the eccentric shaft 225 moves eccentrically, and the eccentric movement of the eccentric shaft 225 is transmitted to the piston 233 via the connecting means 243, and the piston 233 reciprocates in the cylinder 237.

  The refrigerant returned from the refrigeration cycle (not shown) outside the hermetic container 201 is introduced into the compression chamber 241 through the suction muffler 255, and is compressed by the piston 233 in the compression chamber 241. It is sent from the sealed container 201 to the refrigeration cycle.

  Next, the flow of the lubricating oil 203 will be described. The lower end of the shaft 219 is immersed in the lubricating oil 203. When the shaft 219 rotates, the lubricating oil 203 is supplied to each part of the compression element 217 by the oil supply mechanism 227 of the shaft 219, and lubricates the sliding portion. Do.

  Next, the operation of the thin portion 280 provided in the connecting means 243 will be described. As shown in FIG. 7, in the hermetic compressor, a compression load F generated in the piston 233 during the refrigerant gas compression stroke acts on the eccentric shaft 225 via the connecting means 243. When the compression load F acts on the eccentric shaft 225, there is a clearance between the main shaft 223 and the bearing 231, and therefore the shaft 219 is inclined within the clearance range. If the shaft center of the main shaft 223 is tilted by the angle γ as shown in FIG. 7 with respect to the shaft center of the bearing 231, the eccentric shaft 225 is similarly tilted by the angle γ. As a result, the lower end gap b is smaller than the gap a between the upper end of the large end hole 245 and the eccentric shaft 225, and the oil film is thin.

  However, since the oil film pressure is large in the portion where the oil film is thin, the inclination can be absorbed by the thin wall portion 280 being bent, so that the local metal between the eccentric shaft 225 of the shaft 219 and the large end hole portion 245 of the connecting means 243. Wear due to contact can be suppressed. Accordingly, wear due to local metal contact between the eccentric shaft 225 and the large end hole portion 245 of the connecting means 243 can be suppressed by a simple mechanism without increasing the number of parts and weight, thereby improving reliability. it can.

  Further, by forming the thin portion 280 on the entire circumference of the end portion of the large end hole portion 245 of the connecting means 243, the inclination of the eccentric shaft 225 of the shaft 219 due to the compression load generated during the compression stroke is absorbed in all directions. Further, since wear due to local metal contact between the eccentric shaft 225 and the large end hole 245 of the connecting means 243 can be suppressed, the reliability can be further improved.

Further, as shown in FIG. 5, the axial length of the thin portion 280 of the connecting means 243 is H1, the radial thickness of the vertical center position of the large end hole portion 245 is T1, and the thin portion 280 of the end portion is When the thickness in the radial direction is T2, the relationship of T1> T2 and H1> T2 is established, so that the thin portion 280 of the connecting means 243 is easily bent even with a small load. Therefore, even when the compression load generated during the compression stroke is small and the inclination of the eccentric shaft 225 of the shaft 219 is small, the thin portion 280 can be bent. Thereby, the inclination of the eccentric shaft 225 can be absorbed, and wear due to local metal contact between the eccentric shaft 225 of the shaft 219 and the large end hole portion 245 of the connecting means 243 can be suppressed, so that the reliability can be further improved. .

  Further, a groove 284 and an outer wall 282 are provided on the outer peripheral side of the thin wall portion 280. The length from the vertical center position of the large end hole 245 to the end of the thin wall portion 280 is H2, and the length of the large end hole 245 is When the length from the vertical center position to the end of the outer wall portion 282 is H3, the relationship of H3> H2 is established, and a part of the lubricating oil 203 scattered inside the sealed container 201 by the operation of the compressor is thin-walled. It becomes possible to store in the groove portion 284 provided on the outer periphery of the portion 280.

  Further, since the height of the thin wall portion 280 is lower than the outer wall portion 282 stored in the groove portion 284, the lubricating oil 203 overflowing from the groove portion 284 is supplied to the inner surface of the large end hole portion 245 of the connecting means 243 beyond the thin wall portion 280. This is possible, and an oil film can be sufficiently formed between the large end hole 245 and the eccentric shaft 225 of the shaft 219. Thereby, generation | occurrence | production of the metal contact of the eccentric shaft 225 of the shaft 219 and the large end hole part 245 of the connection means 243 can be suppressed, and since wear can be suppressed, reliability can be improved further.

  Specifically, when the outer diameter of the piston 233 is 20 mm, the distance that the eccentric shaft 225 of the shaft 219 tilts due to the compressive load generated under the operating conditions used in the refrigerator, that is, the difference between a and b is 3 μm at the maximum. Then, when H1 which is the axial length of the thin portion 280 provided at the end of the large end hole 245 of the connecting means 243 is 2 mm and T2 which is the radial thickness is 1 mm, the deformation due to the load is 3 μm. The thin portion 280 of the large end hole 245 of the connecting means 243 is deformed following the inclination of the eccentric shaft 225. As a result, the thin-walled portion 280 of the large end hole portion 245 undergoes almost the same deformation with respect to the inclination of the eccentric shaft 225, so that local metal contact can be prevented.

  Further, by providing a dividing groove 286 for connecting the outer peripheral surface of the thin portion 280 and the inner surface of the large end hole 245 in a part of the thin portion 280, the rigidity of the thin portion 280 is reduced by the dividing groove 286, and the thin portion The amount by which 280 can bend increases. As a result, even when the compression load generated during the compression stroke is large as in the overload operation and the inclination of the shaft 219 is increased, the inclination of the eccentric shaft 225 can be absorbed by the thin portion 280. Therefore, since wear due to local metal contact between the eccentric shaft 225 of the shaft 219 and the large end hole 245 of the connecting means 243 can be suppressed, the reliability can be further improved. Further, when the groove portion 284 is provided on the end surface of the large end hole portion 245 of the connecting means 243, the lubricating oil 203 stored in the groove portion 284 can be efficiently supplied to the inner surface of the large end hole portion 245. And an oil film can be sufficiently formed between the shaft 219 and the eccentric shaft 225. Thereby, the metal contact of the eccentric shaft 225 of the shaft 219 and the large end hole 245 of the connecting means 243 can be suppressed, and wear can be suppressed to further improve the reliability.

  In the second embodiment, the thin-walled portion 280 at the end is provided on the entire circumference, but the same effect can be obtained even if it is provided on a portion where the load increases.

  As described above, since the hermetic compressor according to the present invention can improve the reliability by providing a thin wall portion at the end of the large end hole of the connecting means, the air conditioner is not limited to an electric refrigerator-freezer for home use. It can be widely applied to vending machines and other refrigeration equipment.

101, 201 Airtight container 103, 203 Lubricating oil 111, 211 Electric element 113, 213 Stator 115, 215 Rotor 117, 217 Compression element 119, 219 Shaft 121, 221 Flange part 123, 223 Main shaft 125, 225 Eccentric shaft 129, 229 Cylinder block 131, 231 Bearing 133, 233 Piston 137, 237 Cylinder 143, 243 Connection means 145, 245 Large end hole portion 147, 247 Small end hole portion 149, 249 Rod portion 180, 280 Thin portion 282 Outer wall portion 284 Groove portion 286 Dividing groove

Claims (5)

The lubricating oil is stored in an airtight container, and an electric element having a stator and a rotor and a compression element disposed above the electric element are accommodated, and the compression element is fixed to the rotor. A cylinder block including a shaft having a main shaft, an eccentric shaft, and a flange; a cylinder; and a bearing for supporting the main shaft of the shaft; a piston inserted in the cylinder so as to be reciprocally movable; An end hole portion, a small end hole portion, a rod portion, and a connecting means for connecting the piston and the eccentric shaft are provided, and at least a part of the end portion of the large end hole portion of the connecting means is provided. A hermetic compressor in which a thin portion thinner than the radial thickness of the axial center position of the large end hole is formed. The hermetic compressor according to claim 1, wherein the thin portion is provided over the entire circumference of the end of the large end hole of the connecting means. The hermetic compressor according to claim 1 or 2, wherein a length dimension in an axial direction of the thin portion is set larger than a thickness dimension in a radial direction of the thin portion. A groove portion and an outer wall portion are provided on the outer peripheral side of the thin wall portion, and the length from the vertical center position of the large end hole portion to the end portion of the outer wall portion is determined from the vertical center position of the large end hole portion of the thin wall portion. The hermetic compressor according to any one of claims 1 to 3, wherein the hermetic compressor is longer than the length to the end. The hermetic compressor according to any one of claims 1 to 4, wherein a part of the thin part includes a dividing groove that connects an outer peripheral surface of the thin part and an inner surface of the large end hole.