JP2009068386A - Hermetic compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compressor improving performances and reliability by preventing lubricating oil from a vent passage from flowing out to increase oil quantity. <P>SOLUTION: An oiling mechanism 260 pumping up and circulating lubricating oil 204 is provided with a centrifugal pump 262 provided at a lower part of a main shaft part 220 and a spiral groove 266 cut in an outer circumference part of a middle part of the main shaft part 220, and is provided with a communication part 264 keeping communication between an upper part of the centrifugal pump 262 and a lower end of the spiral groove 266, and the vent passage 270 communicating with the centrifugal pump 262 at one end thereof and communicating with an outer circumference part of the main shaft part 220 below the lower end of the spiral groove 266 at another end. Consequently, oil supply quantity is increased by preventing lubricating oil 204 from the vent passage 270 from flowing out while achieving function of discharging refrigerant from the vent passage 270, cooling and lubricating function by the lubricating oil 204 is surely carried out, disturbance of oil film formation at a sliding part by the vent passage 270 is prevented, and performances and reliability are improved. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

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

  Conventionally, as a compressor having an oil supply mechanism using a centrifugal pump on a shaft, a gas vent path is provided below the rotor in order to prevent gas from staying in the centrifugal pump and making it difficult for lubricating oil to flow. (For example, refer to Patent Document 1). In addition, in order to prevent a decrease in the amount of oil supply due to the lubricating oil being discharged from the gas vent path, there is also a gas vent path provided between the rotor and the lower end of the main bearing (for example, patents). Reference 2).

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

  First, a conventional compressor described in Patent Document 1 will be described.

  FIG. 3 is a longitudinal sectional view of a conventional compressor described in Patent Document 1, and FIG. 4 is a sectional view of a conventional oil supply mechanism.

  3 and 4, the lubricating oil 4 is stored at the bottom of the sealed container 2, and the compressor body 6 is elastically supported by the suspension container 8 with respect to the sealed container 2.

  The lubricating oil 4 is compatible with the refrigerant so as to improve fluidity and to easily return to the compressor when discharged into the refrigeration cycle.

  The compressor body 6 includes an electric element 10 and a compression element 12 disposed above the electric element 10. The electric element 10 includes a stator 14 and a rotor 16.

  The shaft 18 of the compression element 12 includes a main shaft portion 20 and an eccentric shaft portion 22. The main shaft portion 20 is rotatably supported by a main bearing 26 of the block 24, and the rotor 16 is fixed. And it is the structure of the cantilever bearing supported with the main axis | shaft part 20 and the main bearing 26 which are arrange | positioned only to the lower side of the eccentric shaft part 22 with respect to the eccentric shaft part 22 to which a load acts.

  The piston 30 is reciprocally inserted into a cylinder 34 having a substantially cylindrical inner surface formed in the block 24. Further, the coupling means 36 couples the eccentric shaft portion 22 and the piston 30 by fitting the hole portions provided at both ends into the piston pin 38 and the eccentric shaft portion 22 attached to the piston 30, respectively.

  The cylinder 34 and the piston 30 form a compression chamber 48 together with the valve plate 46 attached to the opening end surface of the cylinder 34. Further, the cylinder head 50 is fixed so as to cover the valve plate 46 and cover it.

  The suction muffler 52 is molded from a resin such as PBT, forms a silencing space inside, and is attached to the cylinder head 50.

  Further, the shaft 18 includes an oil supply mechanism 60, and the configuration will be described in detail below.

  The oil supply mechanism 60 opens to the lower end of the main shaft portion 20 of the shaft 18, and the centrifugal pump 62, which is a hole inclined in the eccentric direction of the eccentric shaft portion 22 from the shaft center of the main shaft portion 20 as it goes upward, A communication portion 64 that opens from the top to the sliding surface of the main shaft portion 20 that slides with the main bearing 26, and a spiral groove that is engraved on the surface of the main shaft portion 20 and extends from the communication portion 64 to the upper portion of the main shaft portion 20. A spiral groove (one-dot chain line) and an eccentric shaft communication portion 68 that communicates the upper end of the spiral groove and the eccentric shaft portion 22 are provided.

  The oil supply mechanism 60 reaches the upper end of the eccentric shaft portion 22 from the lower end of the main shaft portion 20 immersed in the lubricating oil 4 at the bottom of the sealed container 2 through the centrifugal pump 62, the communication portion 64, the spiral groove, and the eccentric shaft communication portion 68. A series of oil supply passages are formed.

  Further, the oil supply mechanism 60 is provided with a gas vent path 70 that is partly communicated with the inside of the sealed container 2 below the rotor 16 from the centrifugal pump 62. The communication part 64 is provided in a direction in which the upper part of the centrifugal pump 62 is separated from the main shaft part 20, whereas the gas vent path 70 is provided in a direction opposite to the communication part 64.

  About the compressor comprised as mentioned above, the operation | movement is demonstrated below.

  When the electric element 10 is energized, the rotor 16 rotates together with the main shaft portion 20 by the rotating magnetic field generated in the stator 14. Due to the rotation of the main shaft portion 20, the eccentric shaft portion 22 moves eccentrically, and the eccentric movement of the eccentric shaft portion 22 is transmitted to the piston 30 through the connecting means 36, and the piston 30 reciprocates in the cylinder 34.

  The refrigerant returned from the refrigeration cycle (not shown) outside the hermetic container 2 is introduced into the compression chamber 48 via the suction muffler 52, and is compressed by the piston 30 in the compression chamber 48, and the compressed refrigerant is sealed. It is delivered from the container 2 to a refrigeration cycle (not shown).

  Next, the operation of the oil supply mechanism 60 will be described.

  The lower end of the shaft 18 is immersed in the lubricating oil 4, and the lubricating oil 4 that has flowed into the lower portion of the centrifugal pump 62 rotates with the shaft 18 so that a centrifugal force acts, and a parabolic oil as shown by A in FIG. A surface is formed.

  Therefore, the lubricating oil 4 that has flowed into the centrifugal pump 62 flows upward in the vicinity of the wall surface in the centrifugal pump 62 and reaches the communicating portion 64 that is above the oil level B of the lubricating oil 4 at the bottom of the sealed container 2. .

  The lubricating oil 4 guided from the communication portion 64 to the spiral groove on the surface of the main shaft portion 20 flows upward in the spiral groove due to the viscous frictional force caused by the relative speed between the main shaft portion 20 and the main bearing 26.

  Then, the lubricating oil 4 that has flowed upward in the spiral groove reaches the upper end of the shaft 18 while lubricating the eccentric shaft communication portion 68 and the like, and scatters in the space in the sealed container 2.

  Further, since the lubricating oil 4 has compatibility with the refrigerant, a large amount of the refrigerant is dissolved in the lubricating oil 4 when the compressor is stopped. For this reason, when the lubricating oil 4 is stirred, the pressure is lowered, or the temperature is increased at the time of starting the compressor, the refrigerant in the lubricating oil 4 is vaporized or foamed.

  Bubbles due to foaming are also generated in the oil supply mechanism 60. At this time, if the bubbles block the passage of the oil supply mechanism 60, the flow of the lubricating oil 4 is obstructed and the amount of oil supply is reduced. The refrigerant generated by foaming from 70 is discharged from the oil supply mechanism 60 into the sealed container 2, thereby preventing the oil supply from being obstructed by foaming.

  Next, a conventional compressor described in Patent Document 2 will be described.

  FIG. 5 is a vertical cross-sectional view of a conventional compressor described in Patent Document 2, and FIG. 6 is a schematic diagram showing the acting force of each part of the compression element of the conventional compressor.

  5 and 6 show an intermediate position between the top dead center and the bottom dead center.

  In addition, about the same structure as patent document 1, the same code | symbol is attached | subjected and detailed description is abbreviate | omitted.

  In FIG. 5, the oil supply mechanism 160 provided in the shaft 18 opens at the lower end of the main shaft portion 20 of the shaft 18, and the eccentric direction of the eccentric shaft portion 22 increases from the axis of the main shaft portion 20 toward the upper side from the lower end of the main shaft portion 20. A centrifugal pump 162, which is a hole inclined to the main shaft 26, a communication portion 164 that opens from the top of the centrifugal pump 162 to the sliding surface of the main shaft portion 20 that slides with the main bearing 26, and a surface that is engraved on the surface of the main shaft portion 20. A spiral groove 166 that is a spiral groove extending from the portion 164 upward to the main shaft portion 20, an eccentric shaft communication portion (not shown) that communicates the upper end of the spiral groove 166 and the eccentric shaft portion 22, and the like.

  The oil supply mechanism 160 passes through a series of oil supply passages extending from the lower end of the main shaft portion 20 immersed in the lubricating oil 4 at the bottom of the sealed container 2 to the upper end of the eccentric shaft portion 22 via the centrifugal pump 162, the communication portion 164, and the spiral groove 166. Forming.

  Further, the oil supply mechanism 160 is provided with a gas vent passage 170 that partially communicates with the inside of the sealed container 2 at the lower end of the main bearing 26 from the centrifugal pump 162. The communication portion 164 is provided in a direction in which the centrifugal pump 162 is separated from the main shaft portion 20, whereas the gas vent path 170 is opened on the surface of the main shaft portion 20 in the direction opposite to the communication portion 164.

  Further, since the diameter of the gas vent path 170 is sufficiently large with respect to the axial gap between the rotor 16 and the main bearing 26, the gas vent path 170 faces at least a part of the sliding portion of the main bearing 26. It is open.

  About the compressor comprised as mentioned above, the operation | movement is demonstrated centering | focusing on the oil supply mechanism 160. FIG.

  The lower end of the shaft 18 is immersed in the lubricating oil 4, and the lubricating oil 4 flowing into the lower part of the centrifugal pump 162 rotates together with the shaft 18 so that a centrifugal force acts to form a parabolic oil surface.

  Therefore, the lubricating oil 4 that has flowed into the centrifugal pump 162 flows upward in the vicinity of the wall surface in the centrifugal pump 62 and reaches the communicating portion 164 that is above the oil level position of the lubricating oil 4 at the bottom of the sealed container 2.

  The lubricating oil 4 guided from the communication portion 164 to the spiral groove 166 on the surface of the main shaft portion 20 flows upward in the spiral groove 166 due to the viscous frictional force caused by the relative speed between the main shaft portion 20 and the main bearing 26.

  Then, the lubricating oil 4 that has flowed upward in the spiral groove 166 reaches the upper end of the shaft 18 via the eccentric shaft portion 22 and scatters into the space in the sealed container 2.

  Further, the refrigerant evaporated and foamed from the lubricating oil 4 in the centrifugal pump 162 is discharged from the gas vent path 170 to the space in the sealed container 2, thereby preventing the oil supply from being obstructed by the bubbles. Further, since the gas vent path 170 is located at the upper part of the centrifugal pump 162 similarly to the communication part 164, the parabolic oil surface G of the lubricating oil 4 does not flow as shown in FIG. is there.

  Accordingly, the lubricating oil 4 does not flow out from the gas vent passage 170 and the lubricating oil 4 supplied upward from the communication portion 164 does not decrease, so that the cooling effect and the lubricating effect by the lubricating oil 4 do not decrease. , Performance and reliability can be ensured.

  Next, the load acting on the main bearing 26 will be described with reference to FIG.

  As the shaft 18 rotates, the piston 30 reciprocates in the cylinder 34. Assuming that the top dead center is a crank angle of 0 degrees, the compression chamber 48 is reduced in volume and the refrigerant is compressed and the pressure is increased during the compression stroke from the crank angle of 180 degrees. Then, the pressure in the compression chamber 48 becomes the highest in the vicinity of the crank angle from 270 degrees to 360 degrees.

  When the pressure in the compression chamber 48 increases, a load C due to the pressure acts on the piston 30. This load is transmitted from the piston 30 to the eccentric shaft portion 22 via the piston pin 38 and the connecting means 36 and acts as a load D.

  Since the shaft 18 is supported only by the sliding portion of the main shaft portion 20 and the main bearing 26 disposed on the lower side of the eccentric shaft portion 22, the load D acting on the eccentric shaft portion 22 is A load E in the same direction as the load D acts on the upper sliding surface of the main bearing 26, and a load F opposite to the load D acts on the lower sliding surface.

  By the way, the sliding portion constituted by the main shaft portion 20 and the main bearing 26 constitutes a fluid lubrication type journal bearing that supports the load by generating an oil film pressure by the lubricating oil 4 being drawn into a small clearance. Yes.

Therefore, if there is a dent or the like at the position where the load on the sliding surface acts, the generated oil film pressure is reduced. For this reason, the spiral groove 166 and the communication part 164 are arranged so as not to coincide with the directions of the load E and the load F in the latter half of the compression stroke in which the load C during compression increases.
JP-A-63-138175 JP 2006-28065 A

  However, in the conventional configuration described in Patent Document 1, the gas vent path 70 is opened below the rotor 16, so that when the oil level as shown in FIG. The lubricating oil 4 flows out from 70, the lubricating oil 4 supplied upward from the communication part 64 decreases, the cooling effect and the lubricating effect by the lubricating oil 4 decrease, and the performance and reliability are adversely affected. Had.

  Further, in the conventional configuration described in Patent Document 2, since the gas vent passage 170 is disposed on the opposite side of the communicating portion 164 at the lower end of the sliding portion of the main shaft portion 20 and the main bearing 26, the load in the latter half of the compression stroke When the pressure increases, a load acts in the vicinity of the gas vent passage 170, and the oil vent pressure 170 decreases because the gas vent passage 170 exists.

  For this reason, when the viscosity of the oil is further lowered or the width of the sliding portion is made smaller than before, friction and wear due to metal contact occur near the opening of the gas venting path 170, thereby improving the performance. Had the problem of not being able to.

  The present invention solves the above-described conventional problems, and prevents the outflow of lubricating oil from the gas vent passage and the inhibition of oil film formation, and ensures high oil supply and oil film formation to ensure high performance and reliability of the compressor. It aims at realizing.

  In order to solve the above-described conventional problems, a hermetic compressor according to the present invention includes an oil supply mechanism that pumps up and circulates lubricating oil, one end that communicates with a centrifugal pump, and the other end that is below the lower end of the spiral groove. This is equipped with a gas venting path that communicates with the outer peripheral part of the tank, and prevents air supply obstruction due to bubbles in the oiling mechanism by discharging the refrigerant from the gas venting path against bubbles generated by foaming at the time of startup, etc. While increasing the amount of oil supplied, the flow of lubricating oil is prevented from flowing out of the gas vent during stable operation to prevent a decrease in the amount of oil supplied, ensuring cooling and lubrication functions with the lubricant, and the gas vent Has an effect of preventing the oil film formation inhibition of the sliding part due to the opening in the sliding part.

  The hermetic compressor of the present invention has a gas vent passage in which one end communicates with the centrifugal pump, the other end communicates with the outer peripheral portion of the main shaft portion below the lower end of the spiral groove, and at least a part thereof is inclined downward. Therefore, while discharging the refrigerant gas from the oil supply mechanism, the lubricant oil is prevented from flowing out from the gas vent path, thereby preventing a decrease in the amount of oil supplied, and the sliding section of the sliding section by opening the gas vent path to the slide section. Oil film formation inhibition can be prevented, and performance and reliability can be improved.

  The invention according to claim 1 stores lubricating oil in an airtight container, accommodates an electric element including a stator and a rotor, and a compression element driven by the electric element. A shaft having a main shaft portion and an eccentric shaft portion to which the rotor is fixed; a main bearing that supports the shaft; and an oil supply mechanism that pumps and circulates the lubricating oil. A centrifugal pump provided at a lower portion; a spiral groove engraved on an outer peripheral portion of the middle portion of the main shaft portion; a communication portion communicating the upper portion of the centrifugal pump and a lower end of the spiral groove; and one end of the centrifugal pump The other end communicates with the outer peripheral portion of the main shaft portion below the lower end of the spiral groove, and at least a part thereof is inclined downward, and the refrigerant gas is supplied from the oil supply mechanism. While discharging from the gas vent, Preventing lubricant from flowing out of the drainage passage increases oil supply and prevents the oil vent from opening to the sliding portion, preventing the sliding part from forming an oil film, improving performance and reliability To do.

  According to a second aspect of the present invention, in the first aspect of the present invention, one end communicates with the centrifugal pump, the other end reaches the fitting portion between the main shaft portion and the rotor, and the centrifugal pump A gas vent hole that is spaced apart and inclined downward; and a gas vent groove that is formed in a vertical direction, with one end communicating with the gas vent hole and the other end communicating with the inside of the sealed container; In addition to the effects of the invention according to claim 1, in addition to the effect of the invention according to claim 1, the angle at which the gas vent hole tilts downward from the horizontal direction can be reduced and the crossing angle with the centrifugal pump can be increased. It is possible to prevent the formation of a thin part around the opening of the gas vent hole, to prevent the material from falling off due to the tearing of the thin part, and to prevent a decrease in reliability. The shape of the opening is vertical By preventing the oil from flowing out and maintaining the position of the lower end of the opening upward, the outflow of the lubricating oil can be more reliably prevented, and the performance and reliability are improved by preventing a decrease in the oil supply amount. .

  The invention according to claim 3 is the invention according to claim 2, in which the communicating portion and the axial center of the gas vent hole coincide with each other. In addition to the effect of the invention according to claim 2, the communicating portion Since the gas vent holes can be processed simultaneously in one step, the processing is facilitated, the productivity is improved and the cost can be reduced.

  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 cross-sectional view of an oil supply mechanism in the same embodiment.

  In FIGS. 1 and 2, the lubricating oil 204 is stored in the bottom of the sealed container 202, and the compressor body 206 is internally suspended in the sealed container 202 by the suspension spring 208. The sealed container 202 is filled with R600a (isobutane), which is a refrigerant with a low global warming potential.

  The compressor body 206 includes an electric element 210 and a compression element 212 driven by the electric element 210, and a power supply terminal 213 for supplying power to the electric element 210 is attached to the sealed container 202.

  First, the electric element 210 will be described.

  The electric element 210 includes a stator 214 formed by winding a copper coil around an iron core in which thin plates are laminated, and a rotor 216 disposed on the inner diameter side of the stator 214. Is connected to a power supply (not shown) outside the compressor via a power supply terminal 213 by a conducting wire.

  Next, the compression element 212 will be described.

  The compression element 212 is disposed above the electric element 210.

  A shaft 218 constituting the compression element 212 includes a main shaft portion 220 and an eccentric shaft portion 222 parallel to the main shaft portion 220. A rotor 216 is fixed to the main shaft portion 220.

  The block 224 includes a main bearing 226 having a cylindrical inner surface, and the main shaft portion 220 is rotatably inserted into and supported by the main bearing 226. The compression element 212 is configured as a cantilever bearing that supports the load acting on the eccentric shaft portion 222 with the main shaft portion 220 and the main bearing 226 disposed below the eccentric shaft portion 222.

  The block 224 includes a cylinder 234 that is a cylindrical hole, and the piston 230 is reciprocally inserted into the cylinder 234.

  Further, the connecting means 236 is connected to the eccentric shaft portion 222 and the piston 230 by fitting the hole portions provided at both ends into the piston pin 238 and the eccentric shaft portion 222 attached to the piston 230, respectively.

  A valve plate 246 is attached to the end surface of the cylinder 234 and forms a compression chamber 248 together with the cylinder 234 and the piston 230. Further, the cylinder head 250 is fixed so as to cover the valve plate 246 and cover it. The suction muffler 252 is molded from a resin such as PBT, forms a silencing space inside, and is attached to the cylinder head 250.

  Next, the oil supply mechanism 260 provided on the shaft 218 will be described.

  A cap-shaped oil supply cone 261 having a hole at the center of the lower end is attached to the lower end of the main shaft portion 220 of the shaft 218, and the oil supply cone 261 is immersed in the lubricating oil 204 at the bottom of the sealed container 202 so that the inside of the oil supply cone 261 is inside. Also, the lubricating oil 204 flows in.

  The shaft 218 includes a centrifugal pump 262 that is a hole that is inclined away from the axial center of the main shaft portion 220 as it goes above the lower end of the main shaft portion 220, and the surface of the main shaft portion 220 that faces the main bearing 226 from above the centrifugal pump 262. A communication portion 264 that opens to the top, a spiral groove 266 that is a spiral groove carved on the surface of the main shaft portion 220 from the communication portion 264 to the upper portion of the main shaft portion 220, an upper end of the spiral groove 266, and an eccentric shaft portion 222. An eccentric shaft communication portion (not shown) that communicates is provided. A series from the oil supply cone 261 at the lower end of the main shaft portion 220 immersed in the lubricating oil 204 at the bottom of the sealed container 202 to the upper end of the eccentric shaft portion 222 through the centrifugal pump 262, the communication portion 264, the spiral groove 266, and the eccentric shaft communication portion. An oil supply mechanism 260 is formed.

  The oil supply mechanism 260 is provided with a gas vent passage 270. The gas vent passage 270 is a series of passages including a gas vent groove 272 and a gas vent hole 274.

  One end of the gas vent hole 274 communicates with the upper part of the centrifugal pump 262, the other end reaches the fitting portion between the main shaft portion 220 and the rotor 216, and is separated from the centrifugal pump 262 and inclined downward.

  The gas vent groove 272 is a vertical groove formed on the surface of the main shaft portion 220 of the shaft 218, and one end communicates with the gas vent hole 274 at the fitting portion between the main shaft portion 220 and the rotor 216. The end communicates with the sealed container 202.

  Further, the gas vent hole 274 and the communication portion 264 are holes of the same diameter sharing a central axis.

  Further, the communication part 264 is provided in a direction in which the centrifugal pump 262 is separated from the main shaft part 220, whereas the gas vent path 270 is provided in the direction opposite to the communication part 264.

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

  When the electric element 210 is energized from the power supply terminal 213, the rotor 216 rotates with the shaft 218 by the magnetic field generated in the stator 214. The eccentric rotation of the eccentric shaft portion 222 accompanying the rotation of the main shaft portion 220 is converted by the connecting means 236 and causes the piston 230 to reciprocate within the cylinder 234. Then, when the compression chamber 248 changes in volume, the refrigerant in the hermetic container 202 is sucked into the compression chamber 248 and compressed.

  In the suction stroke accompanying this compression operation, the refrigerant in the sealed container 202 is intermittently sucked into the compression chamber 248 via the suction muffler 252 and compressed in the compression chamber 248, and then the high-temperature and high-pressure refrigerant is discharged. It is sent to the refrigeration cycle (not shown) from the sealed container 202 via piping or the like.

  Next, details of the oil supply mechanism 260 will be described.

  The lubricating oil 204 that has flowed into the oil supply cone 261 rotates as the shaft 218 rotates. As a result, a centrifugal force acts on the lubricating oil 204 from the center of the main shaft portion 220 toward the outside, and a parabolic oil surface G as shown in FIG. 2 is formed.

  Therefore, the lubricating oil 204 flowing into the centrifugal pump 262 flows upward in the vicinity of the wall surface in the centrifugal pump 262 and reaches the communication portion 264 above the oil level H of the lubricating oil 204 at the bottom of the sealed container 202. .

  The lubricating oil 204 guided from the communication portion 264 to the spiral groove 266 on the surface of the main shaft portion 220 is a sliding portion between the main shaft portion 220 and the main bearing 226 due to the viscous frictional force generated by the relative speed between the main shaft portion 220 and the main bearing 226. The fluid flows upward in the spiral groove 266 while being lubricated.

  Then, the lubricating oil 204 that has flowed upward in the spiral groove 266 passes through the eccentric shaft communicating portion to the sliding portion of the eccentric shaft portion 222 and the connecting means 236 and the sliding portion of the connecting means 236 and the piston pin 238. Supplied and lubricates each sliding part.

  Further, the lubricating oil 204 scatters from the upper end of the eccentric shaft portion 222 into the space in the sealed container 202, supplies the lubricating oil 204 to the inner wall of the cylinder 234 and the back surface of the piston 230, and lubricates the sliding portion of the cylinder 234 and the piston 230. At the same time, the scattered lubricating oil 204 adheres to the inner wall of the hermetic container 202, thereby accelerating the heat radiation of the compressor from the hermetic container 202 and maintaining the temperature of the compressor low, thereby improving the performance and reliability.

  In addition, since the lubricating oil 204 is compatible with the refrigerant, a large amount of the refrigerant is dissolved in the lubricating oil 204 when the compressor is stopped. For this reason, at the time of starting the compressor, if the lubricating oil 204 is stirred, the pressure is decreased, or the temperature is increased, the refrigerant in the lubricating oil 204 is vaporized or foamed.

  The refrigerant evaporated and foamed from the lubricating oil 204 in the centrifugal pump 262 is discharged from the degassing passage 270 to the space in the sealed container 202. Accordingly, it is possible to prevent the oil supply inhibition that prevents the bubbles from staying in the oil supply mechanism 260 and hindering the flow of the lubricating oil 204, and to prevent the oil supply amount from decreasing.

  Further, since the gas vent hole 274 of the gas vent passage 270 is located at the upper part of the centrifugal pump 262, the parabolic oil surface A as shown in FIG. Moreover, the vent hole 274 does not open directly on the surface of the main shaft 220 below the rotor 216, but opens at the upper end of the vent groove 272 at an angle closer to the horizontal.

  If the inclination angle of the gas vent hole 274 is large and the angle intersecting with the centrifugal pump 262 is small, the opening 264a of the gas vent hole 274 to the centrifugal pump 262 becomes an ellipse that is extremely long in the vertical direction. Even if the center of the opening 274a of the hole 274 is at a high position, the lower end of the opening 274a is at a low position, and the lubricating oil 204 flows out from the gas vent hole 274. However, in the present invention, since the angle is closer to the horizontal, the opening 274a of the gas vent hole 274 to the centrifugal pump 262 can be prevented from becoming extremely long, so that the lubricating oil 204 flows out from the gas vent passage 270. Can be prevented and the amount of oil supply increases.

  Accordingly, the amount of oil supplied to the compression element 212 is increased and the lubrication state of each sliding portion is improved, so that the friction is reduced and the performance is improved, the occurrence of wear is prevented, and the reliability is improved.

  Further, the increase in the amount of oil supply also increases the amount of the lubricating oil 204 that scatters from the upper portion of the compressor body 206, and the lubricating oil 204 adheres to the sealed container 202, thereby promoting heat dissipation from the compressor and the temperature of the compressor. Since the refrigerant can be efficiently compressed, the performance of the compressor is improved. In addition, the temperature can be reduced to prevent an extremely low viscosity and deterioration of the lubricating oil 204, and the reliability is further improved.

  Further, the communication part of the gas vent path 270 into the sealed container 202 is the lower end of the gas vent groove 272 below the rotor 216, and there is an opening that affects the sliding part of the main shaft part 220 and the main bearing 226. Because it does not exist, even if the viscosity of the lubricating oil 204 is lowered or the area of the sliding portion is reduced for improving efficiency, the sliding portion does not cause an oil film breakage, while ensuring reliability. Efficiency can be improved.

  Further, since the inclination of the vent hole 274 to the surface of the centrifugal pump 262 or the main shaft portion 220 can be reduced, and an extremely thin portion can be prevented from being formed on the ridge line portion around the opening portion 274a, the material due to the tearing of the thin portion , Preventing wear due to the broken pieces and improving reliability.

  Further, the gas vent hole 274 and the communication portion 264 of the gas vent passage 270 are holes of the same diameter sharing the central axis, and can be formed by a single drilling process at the time of manufacture. Cost can be reduced.

  The gas vent groove 272 does not necessarily need to be processed, and the number of processing steps can be reduced by forming it with a mold during casting. Furthermore, by drilling the gas vent hole 274 with the gas vent groove 272 as a starting point, the drill tip can be brought into contact with the work at a substantially right angle, so that the drilling process becomes easy and the quality is stabilized.

  As described above, the hermetic compressor according to the present invention increases the amount of oil supply and can improve performance and reliability, so that it is not limited to an electric refrigerator-freezer for home use, but is an air conditioner, a vending machine or other refrigeration apparatus. Widely applicable to etc.

1 is a longitudinal sectional view of a hermetic compressor according to Embodiment 1 of the present invention. Sectional drawing of the oil supply mechanism in the same embodiment Vertical section of a conventional compressor Sectional view of a conventional lubrication mechanism Vertical section of a conventional compressor Schematic diagram showing the working force of each part of the compression element of a conventional compressor

Explanation of symbols

202 Sealed container 204 Lubricating oil 210 Electric element 212 Compression element 214 Stator 216 Rotor 218 Shaft 220 Main shaft part 222 Eccentric shaft part 226 Main bearing 260 Oil supply mechanism 262 Centrifugal pump 264 Communication part 266 Spiral groove 270 Gas vent path 272 Gas vent groove 274 Gas vent hole

Claims (3)

  The lubricating oil is stored in an airtight container, and an electric element having a stator and a rotor and a compression element driven by the electric element are accommodated, and the compression element includes a main shaft portion to which the rotor is fixed. A shaft having an eccentric shaft portion, a main bearing that supports the shaft, and an oil supply mechanism that pumps and circulates the lubricating oil, and the oil supply mechanism is a centrifugal pump provided at a lower portion of the main shaft portion; A spiral groove carved on the outer peripheral part of the middle part of the main shaft part, a communication part communicating the upper part of the centrifugal pump and the lower end of the spiral groove, one end communicating with the centrifugal pump, and the other end of the spiral pump A hermetic compressor provided with a gas vent passage that communicates with an outer peripheral portion of the main shaft portion below the lower end of the groove and at least a part thereof is inclined downward.   The degassing path has one end communicating with the centrifugal pump, the other end reaching the fitting portion between the main shaft portion and the rotor, a degassing hole spaced apart from the centrifugal pump and inclined downward, and a vertical direction 2. The hermetic compressor according to claim 1, further comprising a gas vent groove having one end communicating with the vent hole and the other end communicating with the inside of the sealed container.   The hermetic compressor according to claim 2, wherein the communicating portion and the axial center of the gas vent hole coincide with each other.