JP4652125B2 - Hermetic compressor - Google Patents

Description

  The present invention relates to a hermetic compressor, and is particularly suitable for a hermetic compressor in which a spherical portion provided on a connecting rod and a ball seat provided on a piston are connected.

  As this type of conventional example, there is a hermetic compressor disclosed in Japanese Patent Application Laid-Open No. 2003-184751 (Patent Document 1). This hermetic compressor will be described with reference to FIGS. FIG. 17 is a longitudinal sectional view of a conventional hermetic compressor, FIG. 18 is a diagram showing a coupling relationship between the connecting rod and the piston used in FIG. 17, and FIG. 19 is a diagram of the coupling rod and piston coupled in FIG. It is a figure which shows a relationship.

  Generally, a hermetic compressor used in a refrigeration cycle houses an electric motor 22 and a compression mechanism 23 in a hermetic container 21. The compression mechanism 23 has a crankshaft 26 that rotates eccentrically at the upper end of a shaft 25 that is pivotally supported by a frame 24. A piston 28 that reciprocates in the cylinder 27 is connected to the crankshaft 26 via a connecting rod 29. The sliding portion between the piston 28 and the cylinder 27 and the sliding portion between the connecting rod 29 and the piston 28 are lubricated by lubricating oil scattered from the upper opening 26a of the crankshaft 26 as indicated by an arrow P.

  In particular, in Patent Document 1, in order to make it easy to guide the lubricating oil between the ball seat 34 and the spherical portion 31, the lubricating oil that protrudes from the arrow direction P can be received in the spherical portion 31. A flat portion 31a is formed. That is, the connecting rod 29 is composed of a ring portion 32, a rod portion 33, and a sphere portion 31, and the lubricating oil received by the rod portion 33 is guided to the flat portion 31a of the sphere portion 31, and the spherical portion 31a It leads to the seat 34 part. The ball seat 34 and the sphere 31 are a ball joint connection mechanism that changes the rotational movement of the crankshaft 26 into a reciprocating movement.

Japanese Patent Laid-Open No. 2003-184751

  In Patent Document 1, since the lubrication oil supply to the sliding portion between the ball seat 34 and the sphere portion 31 relies on the intake of the lubricant scattered from the tip of the shaft 25, the lubrication is performed when, for example, the rotational speed drops. There is a possibility that the oil cannot be taken into the ball joint part well. In this case, the oil film is cut off at the sliding part, and the spherical part 31 is burned out.

  By the way, the ball seat 34 of the piston 28 is processed by a precision processing apparatus, and the processing method will be described with reference to FIG.

  As shown in FIG. 20, the ball seat 34 has a small-diameter opening 34a. A shaft 38a of a processing jig 38 is connected to the main shaft 36 of the precision processing apparatus via a universal joint 37, and a spherical blade 38b is provided at the tip of the shaft 38a. The spherical blade 38b rotates at a high speed based on the rotation of the main shaft 36, and processes the ball seat 34 of the piston 28 as a workpiece into a predetermined dimension.

  The outer diameter of the spherical blade 38b is smaller than the inner diameter of the ball seat 34, but has an outer diameter of a certain size. In other words, the circumferential speed of the spherical blade 38b is different from the peripheral speed of the diameter D1 (thickest portion) and the peripheral speed in the vicinity of the central portion (A) of the spherical blade 38b. In the vicinity processed at the portion (A), the finishing accuracy of the portion (B) is high, and the accuracy processed at the portion (A) is low.

  When the spherical seat 38b is processed by the spherical cutter 38b, the portion processed by the (A) portion of the spherical cutter 38b has a plus tolerance dimension when the center 34b of the spherical seat 34 is used as a reference. This is because the part to be machined by the part becomes excessively shaved due to the difference in peripheral speed, resulting in a minus tolerance.

  And when processing the ball seat 34 with the undercut part by the latching | locking part 34a, the axis | shaft 38a is bent like a broken line using the universal joint 37, or the piston side used as a workpiece is moved, The said undercut part Is to process.

  That is, the processing method of the ball seat 34 of the piston 28 is to make the ball seat 34 by mounting the spherical blade 38b on the rotating shaft 36 of the finishing device and rotating the spherical blade 38b. Accordingly, a universal joint is interposed between the rotary shaft 36 and the spherical blade 38b, and the spherical blade 38b is inclined as shown by the broken line in FIG. The ball seat is processed by moving along the shape.

  For example, as shown in FIG. 20, the spherical blade 38b has an elliptical spherical shape when viewed from the front. Therefore, the peripheral speed at the time of machining differs between the center of the spherical blade 38b and the outer periphery of the spherical blade 38b by the difference in diameter. ing. Therefore, in any of the above-described processing methods, a place processed at a place where the peripheral speed is fast has good finishing precision, and a part processed at a place where the peripheral speed is low is not good. In other words, the finishing accuracy at a position away from the center of the ball seat is good, but the finishing accuracy near the center is not as good as the others. When the spherical body portion 31 on the connecting rod side is received at a place where the surface finish is poor and the processing accuracy is not good, the spherical body portion 31 or the spherical seat 34 may be damaged due to friction, which may cause abnormal noise.

  Furthermore, according to the drawing of Patent Document 1, although the concave portion is provided in the ball seat, the relevance to the oil supply mechanism is not taken into consideration, and the sliding portion between the ball seat and the spherical portion is not considered. The relationship with the supply of lubricating oil was unclear.

  An object of the present invention is to provide a hermetic compressor having an advantageous structure in terms of cost, high efficiency, and excellent reliability. Other objects and advantages of the present invention will become apparent from the following description.

In order to achieve the above-described object, the present invention provides a crankshaft for transmitting a rotational force from an electric motor, a piston having a spherical seat having a spherical portion on the crankshaft side, and a spherical portion connected to the spherical seat at one end. A connecting rod having a ring portion fitted to the crankshaft at the other end, a rod portion connecting the ring portion and the spherical portion, and lubricating oil stored in a sealed container, and the crank In a hermetic compressor in which the lubricating oil is supplied through a shaft, the crankshaft is provided with a first oiling hole, and the connecting rod receives the lubricating oil from the first oiling hole in the ball seat. the second oil supply hole is provided in the first oil pocket for storing temporarily lubricating oil flowing out from the second oil supply hole by the recess provided in the ball seat to be supplied to provided, the first outer peripheral surface of the crankshaft Communicate with 1 oiling hole Forming a second oil pocket, the tip of the spherical portion which slides in the ball seat is a shape recessed from a true spherical shape, and the upper and lower surfaces of the spherical body is removed a predetermined range of spherical An oil supply groove that communicates with the first oil pocket and extends to the flat cut portion on the outer surface of the spherical body portion , and is provided with movement of the piston and the connecting rod. A groove is configured to intermittently communicate with the first oil pocket, and in the gas suction step of the piston, the oil supply groove and the first oil pocket communicate with each other, and the second oil pocket The second oil supply hole is communicated, and in the gas compression step, the communication between the oil supply groove and the first oil pocket and the communication between the second oil pocket and the second oil supply hole are released. ,and The lubricating oil of the oil supply groove lies in that is configured to lubrication between the spherical portion and the spherical base.

According to the present invention, the first oil pocket for temporarily storing the lubricating oil from the second oil supply hole is provided by the concave portion provided in the ball seat, and the upper and lower surfaces of the spherical body portion are a flat cut portion in which a predetermined range is removed from the spherical shape. And an oil supply groove that communicates with the first oil pocket and extends to the flat cut portion is provided on the outer surface of the sphere, and the oil supply groove is provided in the first oil pocket as the piston and the connecting rod move. In the piston gas suction step, the oil supply groove and the first oil pocket are in communication with each other, the second oil pocket and the second oil supply hole are in communication, and the gas compression step. Then, the communication between the oil supply groove and the first oil pocket and the communication between the second oil pocket and the second oil supply hole are released, and the lubricating oil in the oil supply groove is removed from the ball seat. Between the sphere Since the oil is supplied, the lubricating oil enters the oil supply groove from the first oil pocket in the gas suction step, and at that time, the first oil hole, the second oil pocket, and the second oil supply hole pass through the first oil pocket. Lubricating oil is supplied to the oil pocket, and the communication between the first oil pocket and the oil supply groove is released in the gas compression process under load, and the lubricating oil in the oil supply groove is supplied to the sliding part between the ball seat and the sphere part. since the sliding portion according to the time of gas compression process load is Ki out possible to prevent the sintered by oil film shortage, in which hermetic compressor with excellent reliability can be obtained.
In addition, since the tip of the sphere that slides inside the sphere seat has a shape that is recessed from the true sphere shape, sliding between the inferior processing accuracy in the sphere seat and the sphere portion can be avoided, Deterioration of the ball joint portion due to friction can be reduced.
Furthermore, since the first oil pocket is constituted by the recess provided in the ball seat, the first oil pocket can be easily formed.
Further, since the second oil pocket communicating with the first oil supply hole is formed on the outer peripheral surface of the crankshaft, the second oil pocket is supplied when the lubricating oil is supplied to the first oil pocket. Sufficient lubricating oil can be supplied to the second oil supply hole and the first oil pocket through the oil pocket.

  The details of the present invention will be described with reference to an embodiment shown in the drawings.

  First, a description will be given with reference to FIGS. 1 is a longitudinal sectional view showing an embodiment of a hermetic compressor according to the present invention, FIG. 2 is a longitudinal sectional view showing the shape of the piston of FIG. 1, and FIG. 3 is a side view of the piston of FIG. 4 and 4 are side sectional views showing an example in which the connecting rod and the crankshaft of FIG. 1 are combined.

  As shown in FIG. 1, the hermetic compressor is provided with an electric motor 2 and a compression mechanism unit 3 inside a hermetic container 1. The frame 4 supports the electric motor 2 and the compression mechanism unit 3 in the sealed container 1. The shaft 5 is supported by the frame 4 to which the rotor of the electric motor 2 is fixed. A crankshaft 6 is provided at the upper end of the shaft 5. In order to drive the piston 8 with respect to the cylinder 7, a connecting rod 9 is provided between the crankshaft 6 and the piston 8.

  Thus, the connection between the piston 8 and the connecting rod 9 is generally a connection of a ball joint type. That is, the sphere 11 of the connecting rod 9 is slidably fitted to the ball seat 8a on the piston 8 side. The connecting rod 9 includes a rod portion 10, a spherical body portion 11 that is in solid contact with one end of the rod portion 10, and a ring 12 that slides on the crankshaft 6 that is in solid contact with the other end of the rod portion 10.

  As described above, in the hermetic compressor used in the refrigeration cycle, the electric motor 2 and the compression mechanism unit 3 are accommodated in the hermetic container 1.

  The compression mechanism 3 is configured at the upper end of a shaft 5 that is pivotally supported by the frame 4. As the compression mechanism portion 3, an eccentric rotating crankshaft 6, a piston 8 reciprocatingly sliding inside the cylinder 7, a ring 12 connected to the crankshaft 6, and a sphere portion 11 connected to the piston 8 are integrated with a rod portion 10. It is comprised from the connecting rod 9 fixed to.

  As shown in FIG. 1, the connecting rod 9 and the piston 8 are connected by a ball joint method in which a spherical body portion 11 and a ball seat 8a of the piston 8 are combined.

  As shown in FIGS. 2 and 3, the piston 8 is provided with a ball seat 8 a for accommodating the spherical body portion 11 of the connecting rod 9. Further, the piston 8 is provided with a hole 8c which is enlarged in an umbrella shape from the opening 8b (FIG. 3) having an arbitrary size smaller than the inner diameter of the ball seat 8a to the piston end face side. Further, the insertion groove 8d serving as an insertion port for inserting the spherical portion 11 has a bottom portion 8e extending to a position on an extension line of the spherical diameter center of the spherical seat 8a, and is provided symmetrically with respect to the center line YY of the piston 8. ing.

As shown in FIG. 4, the connecting rod 9, the spherical portion 11 at one end of the rod 1 0 is joined to the other end of the rod portion 1 0 of the ring 12 by welding or the like. The spherical body part 11 has a plane cut part 11a in which a certain range in the vertical direction is removed from the spherical shape shown by the one-dot chain line in FIG. The flat cut portion 11a is formed in parallel with the end surface 12a of the ring 12, that is, in parallel with the upper and lower surfaces. These flat cut portions 11 a do not necessarily have to be parallel, but are preferably formed in parallel in terms of the formation of the opening 8 b of the piston 8 and the strength of the connecting rod 9.

  The second oil supply hole 18 is provided in the shaft core of the connecting rod 9, and the first oil supply hole 19 is provided in the crankshaft 6. The first oil supply hole 19 and the second oil supply hole 8 communicate with each other when the holes of the crankshaft 6 coincide with each other, and the lubricating oil that has risen in the crankshaft 6 is directed to the connecting rod 9 side. Refueled. Then, the lubricating oil supplied to the connecting rod 9 from the first oil supply hole 19 passes through the first oil supply hole 18 and is supplied into the oil pocket 20. By doing so, the lubricating oil is almost forcibly supplied to the oil pocket 20 from one to the next, so that the new lubricating oil is sent out between the sphere 11 and the ball seat 8a via the oil pocket 20. is there.

  Of course, the clearance between the sphere 11 and the ball seat 8a is very small, 2 to 5 microns, so that the amount of lubricating oil delivered is small, but the amount required when both slide can be satisfied. It is. That is, the clearance is always protected by the oil film without breaking the oil film.

  Further, the supply of the lubricating oil to the oil pocket 20 is satisfied even at the time of a low speed rotation of a recent hermetic compressor that changes the rotation speed.

  Further, the lubricating oil that blows out from the upper opening of the crankshaft 6 is lubricated in the same manner as in the past between the compression mechanism portion 3 and between the spherical portion 11 and the ball seat 8a. Thus, the compression mechanism portion 3 and the ball joint portion 13 are surely lubricated and cooled.

  Next, a description will be given with reference to FIGS. 5 is a cross-sectional view showing the first step of the method of assembling the piston and connecting rod of FIG. 1, FIG. 6 is a cross-sectional view taken along the line AA of FIG. 5, and FIG. 7 is a cross-sectional view showing the next step of FIG. 8 is a cross-sectional view taken along line BB in FIG. These drawings show an assembling method of the ball joint portion 13 of the piston 8 and the connecting rod 9. 5 and 7 show that the connecting rod 9 is inserted into the piston 8 in a state where the ring 12 is tilted at a substantially right angle to the direction in which the ring 12 is actually used inside the hermetic compressor (the ring 12 is tilted vertically). It is sectional drawing which shows the ball joint part 13 when it did.

  First, as shown in FIG. 6, the positions of the insertion groove 8d of the piston 8 and the flat cut portion 11a of the connecting rod 9 are aligned, and the sphere portion 11 is inserted into the insertion groove 8d, and then the sphere as shown in FIG. The part 11 is brought into close contact with the ball seat 8a. That is, the spherical body part 11 enters the undercut part (umbrella-shaped hole 8c) of the ball seat 8a.

  Further, as shown in FIGS. 7 and 8, by rotating the piston 8 and the connecting rod 9 by substantially a right angle, the sphere 11 is connected to the opening 8b having a smaller diameter (using an undercut portion). ), The ball joint portion 13 is completed without coming off. A space 14 is formed by the insertion groove 8d of the piston 8 and the flat cut portion 11a of the spherical body 11, and a part of the spherical seat 8a is exposed.

  Next, a description will be given with reference to FIGS. FIG. 9 is a longitudinal sectional view showing a method of supplying oil to the ball joint portion of FIG. 1, FIG. 10 is a view showing the point immediately before starting oil supply to the ball joint portion of FIG. 1, and FIG. FIG. 12 is a diagram showing the transition of the oil supply mechanism, FIG. 12 is a diagram showing the moment when the oil supply to the ball joint portion in FIG. 1 is finished, and FIG. 13 is a diagram in which an oil supply groove is provided on the outer surface of the connecting rod in FIG. 14 is an enlarged cross-sectional view taken along the line CC of FIG. 13, FIG. 15 is a view showing a second oil pocket provided including the first oil supply hole provided in the crankshaft of FIG. 1, and FIG. It is DD expanded sectional drawing.

In the assembled state of the hermetic compressor shown in FIG. 9, the lubricating oil scattered from the tip of the crankshaft 6 is supplied to the lubrication of the ball seat 8a, and the sliding reliability of the ball joint portion 13 can be ensured. That is, the lubricating oil pulled up from the oil reservoir through the hole 6 a provided in the crankshaft 6 through the shaft 5 scatters from the tip of the crankshaft 6. Part of the scattered lubricating oil flows toward the inside of the piston 8 along the rod portion 10 of the connecting rod 9. The lubricating oil that has flown into the piston 8 flows along the hole 8 c of the piston 8 into the space 14 formed by the insertion groove 8 d and the flat cut portion 11 a of the sphere 11. Further, in the present embodiment, the lubricant oil is supplied to the ball seat 8a when the lubricant oil reaches the space formed by the ball seat 8a and the plane cut portion 11a that communicates with the space 14.

  In the present embodiment, the oil supply to the ball joint portion 13 is not only due to the scattering from the upper end of the crankshaft 6 described above, but also the following three forcibly supplying the lubricant oil directly to the ball joint portion 13. There is a means.

  First, the first means is a means for supplying the lubricating oil lifted on the crankshaft 6 to the ball joint portion 13 by a spiral groove or the like in the shaft 5.

  As shown in FIG. 9, the first oil supply hole 19 is provided in the crankshaft 6 and the second oil supply hole 18 is provided in the connecting rod 9, and the second on the connecting rod 9 side in the course of one rotation of the crankshaft 6. When the oil supply hole 18 and the first oil supply hole 19 coincide with each other, oil is supplied from the crankshaft 6 side to the connecting rod 9 side, and the supplied oil is connected to the spherical body portion 11 at the tip of the connecting rod 9. It is means for supplying oil to the ball joint portion 13 in which the ball seat 8a and the sphere portion 11 slide through the hole 18.

  By adopting this first means, lubricating oil is sufficiently supplied to the ball joint portion 13, but there is an insufficient point in that an oil film is formed on the entire ball joint portion 13. . This is because the clearance between the ball portion 11 forming the ball joint portion 13 and the ball seat 8a is as very small as 2 to 5 microns, so that the lubricating oil discharged from the second oil supply hole 18 is fed to the entire surface. In terms of spreading, the diameter of the second oil supply hole 18 was about 3 mm, which was too small. Since the diameter of the connecting rod 9 of the hermetic compressor originally used in a refrigerator or the like is about 6 mm, the second oil supply hole 18 is naturally about 3 mm for reasons of strength. It is difficult to spread the lubricating oil over the entire ball joint portion 13 including the spherical body portion 11 having a size of about 3 mm at about 3 mm.

  Therefore, in the present embodiment, as a second means, an oil pocket is provided between the ball seat 8a and the spherical body portion 11 for temporarily storing the lubricating oil that has come out from the second oil supply hole 18. More specifically, the ball seat 8a corresponding to the opening of the second oil supply hole 18 is formed with an oil pocket 20 that is a recess of 6 mm corresponding to a diameter larger than 3 mm of the diameter of the second oil supply hole 18. It is. By the formation of the oil pocket 20, the supply of lubricating oil to the ball joint portion 13 is almost achieved, and an oil film is formed on the entire clearance portion.

  It should be noted that the provision of the oil pocket 20 facilitates the formation of the ball seat 8a as described above.

  There is also a means for further improving the efficiency by further reinforcing the second means. This is the third means. That is, it is a means for forming the oil supply groove 17 on the outer surface of the spherical portion 11. The oil supply groove 17 is formed by forming a groove having a width of about 1.5 mm and a depth of about 1 mm on the outer surface of the sphere 11 as shown in FIGS.

  The relationship between the oil supply groove 17 and the oil pocket 20 is to supply the ball joint portion 13 evenly as shown in FIGS. That is, when the relationship between the piston 8 and the cylinder 7 is divided into a suction process and a compression process, the oil supply groove 17 enters the compression process when the oil supply groove 17 enters the opening of the oil pocket 20 in the suction process. By providing it at a position away from 20, the lubricating oil in the oil pocket 20 is supplied to the ball joint portion 13 so as not to cause an oil film breakage when a load is applied in the compression process.

  This will be described with reference to FIGS. FIG. 10 is a diagram showing a state immediately before the start of oil supply to the ball joint portion 13, FIG. 11 is a diagram showing a state in which oil supply to the ball joint portion 13 is being performed, and FIG. FIG. Of course, since the piston 8 is connected to the crankshaft 6 via the connecting rod 9, the connecting rod 9 and the crankshaft 6 are variable as shown in FIGS. In the drawing, 0 to 197 degrees and 343 degrees to 360 degrees, which are in the compression process, are omitted, and the description will be focused on how the oil pocket 20 is supplied to the oil supply groove 17.

  First, the oil supply groove 17 is disengaged from the oil pocket 20 before the suction start of FIG. At this time, the first oil supply hole 19 provided in the crankshaft 6 and the second oil supply hole 18 provided in the connecting rod 9 are in a mismatched state as shown in the drawing. Accordingly, no new lubricating oil is supplied to the oil pocket 20 at this stage.

  As shown in FIG. 11, when the rotation angle of the crankshaft 6 reaches 198 degrees, the oil supply groove 17 enters the oil pocket 20. At this stage, since the first oil supply hole 19 and the second oil supply hole 18 are not yet communicated with each other, sufficient lubricating oil does not exist in the oil pocket 20, but the rotation angle of the crankshaft 6 is 235. When the angle is about 315 degrees, lubricating oil is supplied to the oil pocket 20 from the crankshaft 6 side. When the supplied lubricating oil is filled in the oil pocket 20, the lubricating oil enters the oil supply groove 17 to prepare for the next movement.

  Then, as shown in FIG. 12, when entering the compression process in which communication between the first oil supply hole 19 and the second oil supply hole 18, the oil supply groove 17, and the oil pocket 20 is released, only the lubricating oil in the oil supply groove 17 The joint part 13 will be refueled. And when the compression process ends, the movement of entering the suction process again is repeated.

  By providing a second oil pocket 16 as shown in FIG. 10 around the first oil supply hole 19 provided in the crankshaft 6, the communication time with the second oil supply hole 18 is increased, thereby further ensuring the amount of oil supply. It is something that can be done.

  Since the present embodiment has the configuration as described above, it has the following effects.

That is, a crankshaft transmitting torque from the electric motor, a piston having a spherical seat having a spherical surface on the crankshaft side, a spherical portion connected to the spherical seat at one end, and the crankshaft at the other end A connecting rod having a ring part and a rod part connecting the ring part and the spherical body part, and a lubricating oil stored in a sealed container, and the lubricating oil is supplied through the crankshaft. In the hermetic compressor, the crankshaft is provided with a first oil supply hole, and the connecting rod is provided with a second oil supply hole for supplying lubricating oil from the first oil supply hole to the ball seat, Since an oil pocket is provided between the ball seat and the sphere portion to temporarily store the lubricating oil that has come out of the second oil supply hole, the lubricating oil is directly supplied to the oil pocket through the oil supply hole, and the connecting lock is provided. The sliding part between the ball part on the side and the ball seat on the piston side can be lubricated with the lubricating oil in the oil pocket, and it is possible to prevent the sliding part from being sintered due to oil film breakage. A hermetic compressor excellent in performance can be obtained. In addition, since no special member is required to supply the lubricating oil to the sliding portion, an efficient hermetic compressor can be obtained with a structure advantageous in terms of cost.

  Further, since the oil pocket is constituted by the concave portion provided in the ball seat, the oil pocket can be easily formed.

  Further, since the opening of the oil pocket is made larger than the diameter of the second oil supply hole, when the spherical portion on the connecting rod side slides in the piston side ball seat, it contacts the lubricating oil in the oil pocket. The surface is enlarged, and the lubricating oil around the sliding portion is further improved.

In addition, an oil pocket provided between the ball seat and the sphere portion is used as a first oil pocket, and the second oil pocket is formed to include the first oil supply hole by using either the crankshaft or the ring portion. since those formed, when the supply of lubricating oil to the second oil supply hole communicating with one crankshaft revolution is Ru performed, the first oil through the second oil supply hole from the second oil pocket Sufficient lubricating oil can be supplied to the pocket.

  In addition, since the second oil pocket is formed within the thickness of the crankshaft, the second oil pocket can be simultaneously processed at the time of processing the first oil supply hole provided in the crankshaft, and the productivity is good. Since no special parts are used, it can be advantageous in terms of cost.

  Also, since the oil supply groove communicating with the oil pocket is provided on the outer surface of the sphere that slides inside the ball seat, lubricating oil is supplied to the sliding portion between the ball seat and the ball portion via the oil supply mechanism. Therefore, the oil film can be more reliably prevented from being cut.

  Also, since the oil supply groove is configured so that the oil pocket and the outside of the ball seat are intermittently communicated with the movement of the piston and the connecting rod, the lubricating oil stored in the oil pocket is gradually released to the outside. It can be discharged and replaced with fresh lubricating oil, and the sliding characteristics can be improved from this point.

  In addition, the oil supply groove and the oil pocket are connected in the gas suction process of the piston and the communication is released in the gas compression process. Since the lubricating oil can be supplied to the moving part, it is possible to provide a structure in which the lubricating oil in the ball joint part is easily replaced and is not easily removed, and the reliability can be greatly improved.

  In addition, since the spherical part of the connecting rod is formed on the spherical part of the piston side spherical seat processed by the central part of the spherical cutter, a concave oil pocket is formed in the spherical seat so that it does not come into contact with the spherical part. The ball seat or the sphere part is not damaged by sliding with the part.

  Furthermore, since the concave oil pocket 20 is provided in the center portion on the back side of the ball seat 8a, the ball joint portion 13 of the connecting rod 9 is caused by sliding with a portion of the ball seat 8a having inferior processing accuracy. Wear can be reduced. Further, a second oil supply hole 18 is provided at the tip of the ball joint part (sphere part) 13, and the tip of the sphere part that is most likely to be worn by sliding has a shape that is recessed in advance than the true spherical shape. Therefore, sliding between the inferior machining accuracy portion in the ball seat 8a and the spherical portion can be avoided, and deterioration of the ball joint portion 13 due to friction can be reduced.

1 is a longitudinal sectional view showing an embodiment of a hermetic compressor according to the present invention. It is a longitudinal cross-sectional view which shows the shape of the piston of FIG. It is the side view which looked at the piston of FIG. 2 from the arrow direction. It is a sectional side view which shows an example which combined the connecting rod and crankshaft of FIG. It is a figure which shows the first process of the assembly method of the piston of FIG. 1, and a connecting rod. It is AA sectional drawing of FIG. It is a figure which shows the next process of FIG. It is BB sectional drawing of FIG. It is a longitudinal cross-sectional view which shows the oil supply method to the ball joint part of FIG. It is a figure which shows the just before starting the oil supply to the ball joint part of FIG. It is a figure which shows the transition of the oil supply mechanism to the ball joint part of FIG. It is a figure which shows the moment which complete | finished the oil supply to the ball joint part of FIG. It is the figure which provided the oil supply groove | channel in the spherical body part outer surface of the connecting rod of FIG. It is CC sectional enlarged view of FIG. It is a figure which shows the 2nd oil pocket part provided including the 1st oil supply hole provided in the crankshaft of FIG. It is DD expanded sectional drawing of FIG. It is a longitudinal cross-sectional view of the conventional hermetic compressor. It is a figure which shows the connection relation of the connecting rod and piston which are used for FIG. It is a figure which shows the relationship between the connecting rod couple | bonded in FIG. 18, and a piston. It is a figure which shows the processing method of the ball seat formed in the piston side.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Sealed container, 2 ... Electric motor, 3 ... Compression mechanism part, 4 ... Frame, 5 ... Shaft, 6 ... Crankshaft, 6a ... Hole, 7 ... Cylinder, 8 ... Piston, 8a ... Ball seat, 8b ... Small diameter opening Part, 8c ... Umbrella-shaped hole, 8d ... insertion groove, 8e ... bottom part, 9 ... connecting rod, 10 ... rod part, 11 ... sphere part, 11a ... plane cut part, 12 ... ring part, 12a ... end face, 13 ... ball joint portion, 14 ... space, 16 ... second oil pocket, 17 ... feed oil grooves, 18 ... second oil supply hole, 19 ... first oil supply hole, 20 ... oil pocket (first oil pocket )

Claims (1)

A crankshaft that transmits the rotational force from the motor,
A piston with a spherical seat having a spherical surface on the crankshaft side;
A connecting rod having a sphere part connected to the spherical seat at one end, a ring part fitted to the crankshaft at the other end, and a rod part connecting the ring part and the sphere part;
Lubricating oil stored in a sealed container,
In the hermetic compressor in which the lubricating oil is supplied through the crankshaft,
Providing a first oiling hole in the crankshaft;
The connecting rod is provided with a second oil supply hole for supplying the lubricating oil from the first oil supply hole to the ball seat,
Providing a first oil pocket for temporarily storing the lubricating oil from the second oil supply hole by a recess provided in the ball seat;
Forming a second oil pocket communicating with the first oil supply hole on the outer peripheral surface of the crankshaft;
The tip of the sphere that slides inside the sphere seat has a shape that is recessed from the true sphere, and the upper and lower surfaces of the sphere have a plane cut portion that removes a predetermined range from the sphere. the oil groove that extends to the plane cut portion communicated with provided on the outer surface of the spherical body in the first oil pocket,
The oil supply groove is configured to intermittently communicate with the first oil pocket as the piston and the connecting rod move.
In the gas suction step of the piston, the oil supply groove and the first oil pocket communicate with each other, and the second oil pocket and the second oil supply hole communicate with each other. In the gas compression step, the oil supply groove and The communication with the first oil pocket and the communication between the second oil pocket and the second oil supply hole are released, and the lubricating oil in the oil supply groove is removed between the ball seat and the spherical body portion. A hermetic compressor characterized in that it is configured to refuel .

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