JP2013019328A - Hermetic compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem wherein reduction of a cross section of a chamfer provided on a thrust surface causes a discharge amount of a lubricant from an oil groove provided on the thrust surface to be reduced; a circulation amount of the lubricant to be reduced; and the efficiency of cooling the lubricant and lubrication to each sliding part to be shortage.SOLUTION: On the chamfer 127, the cross section on a side on which a compressive load acts away from a compression chamber 117 is larger than that on a side near the compression chamber 117. Accordingly, a sliding area is secured on a side where the compressive load is applied, and a sliding area is reduced on a side where the compressive load is not applied. As a result, the hermetic compressor maintains high reliability and efficiency.

Description

  The present invention relates to a hermetic compressor used in a refrigerator-freezer or the like.

  In recent years, high efficiency and high reliability are desired for hermetic compressors used in refrigeration apparatuses such as refrigerators and refrigerators in order to reduce power consumption.

  In general, this type of hermetic compressor has a structure in which a block as a support frame, a compression element at the lower part of the cylinder block, and an electric element at the upper part of the cylinder block are arranged in a hermetic container. ing.

  Then, the shaft on which the rotor of the electric element is fixed is rotatably supported by a bearing provided substantially at the center of the cylinder block, and the driving force of the electric element is transmitted to the compression element by the rotation of the shaft ( For example, see Patent Document 1).

  The conventional hermetic compressor will be described below with reference to the drawings.

  6 is a longitudinal sectional view of a conventional hermetic compressor described in Patent Document 1, FIG. 7 is an enlarged cross-sectional view of a main part of the conventional hermetic compressor, and FIG. 8 is a bearing in the conventional hermetic compression. FIG.

  6 to 8, the hermetic container 1 houses an electric element 2 composed of a stator 52 and a rotor 54, and a compression element 4 that is rotationally driven by the electric element 2, and has a lubricating oil at the bottom. 6 is stored. The electric element 2 and the compression element 4 are assembled together to form a compression mechanism 8. The compression mechanism 8 is elastically supported in the sealed container 1 by a plurality of coil springs (not shown). .

  A cylindrical compression chamber 22 is formed in the cylinder block 20 constituting the compression element 4, and a piston 24 is reciprocally inserted into the compression chamber 22. A bearing 26 is fixed to the upper part of the cylinder block 20, and an oil groove 56 for discharging oil is provided on a thrust surface 55 above the bearing 26, and a chamfer 57 is formed on the inner diameter side of the thrust surface 55.

  The shaft 30 includes a main shaft portion 34 that is pivotally supported by the bearing 26 in the vertical direction and has a spiral oil supply groove 32 on the outer periphery thereof, and an eccentric shaft portion 36 formed below the main shaft portion 34, and the eccentric shaft portion 36 and the piston 24. Are connected by a connecting mechanism 44.

  A pipe-shaped oil supply pipe 42 is press-fitted into an oil supply hole (not shown) formed at the lower end of the eccentric shaft portion 36, and one end of the oil supply pipe 42 communicates with the helical oil supply groove 32 from the oil supply hole. Yes.

  The electric element 2 includes a stator 52 fixed above the cylinder block 20 and a rotor 54 fixed to the main shaft portion 34 of the shaft 30 by shrink fitting or the like.

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

  When the electric element 2 is energized from an external power source, the rotor 54 rotates, and the shaft 30 rotates accordingly, and the rotational movement of the eccentric shaft portion 36 is transmitted to the piston 24 via the coupling mechanism 44. The piston 24 reciprocates in the compression chamber 22, and the compression element 4 performs a predetermined compression operation.

  Thereby, the refrigerant gas is sucked into the compression chamber 22 from a cooling system (not shown), compressed, and then discharged again to the cooling system.

  At this time, the oil supply pipe 42 pumps up the lubricating oil 6 by centrifugal force and lubricates each sliding portion (not shown), and a part thereof is provided on the thrust surface 55 through the spiral oil supply groove 32. The lubricating oil 6 discharged from the oil groove 56 returns to the bottom of the sealed container 1 by gravity.

Japanese Patent Laid-Open No. 62-247187

  However, in the conventional configuration, the cross-sectional area of the chamfered portion provided on the thrust surface may be reduced due to processing variations. When the cross-sectional area of the chamfered portion is reduced, the amount of lubricating oil discharged from the oil groove provided on the thrust surface is reduced, so the circulating amount of lubricating oil is reduced, and the cooling effect of the lubricating oil and the effect on each sliding portion are reduced. There was a possibility of insufficient lubrication. In addition, if the cross-sectional area of the chamfered portion is large from the beginning, the sliding area and thrust area of the bearing inner diameter portion are reduced, so that the surface pressure may increase and reliability may be lowered.

  The present invention solves the above-described conventional problems, and an object of the present invention is to obtain high reliability and high efficiency in a hermetic compressor.

  In order to solve the above conventional problems, a hermetic compressor according to the present invention is provided with a thrust washer between a thrust surface provided at the upper part of a bearing and a rotor, and an oil groove for discharging oil is provided on the thrust surface. A chamfered portion is provided on the inner diameter side of the thrust surface, and the chamfered portion is formed so that the cross-sectional area on the side farther from the compression chamber is larger than the side closer to the compression chamber side. By increasing the cross-sectional area of the chamfered portion on the opposite side to which the compressive load is applied, the sliding area on the side to which the compressive load is applied can be ensured while ensuring the cross-sectional area. Therefore, the sliding area on the side where the compressive load is not applied is reduced, and the reliability and efficiency are improved.

  The hermetic compressor of the present invention has a chamfered portion on the inner diameter side of the thrust surface, and the chamfered portion is formed so that the cross-sectional area on the side farther from the compression chamber is larger than the side closer to the compression chamber side. Thus, by increasing the cross-sectional area of the chamfered portion on the opposite side where the compressive load is applied, the sliding area on the side where the compressive load is applied can be ensured while ensuring the total cross-sectional area of the chamfered portion. Therefore, since the sliding area on the side where no compression load is applied can be reduced, a highly reliable and highly efficient hermetic compressor can be provided.

1 is a longitudinal sectional view of a hermetic compressor according to Embodiment 1 of the present invention. The principal part expanded sectional view of the thrust part of the hermetic compressor in Embodiment 1 Sectional drawing of the bearing of the hermetic compressor in Embodiment 1 Front view of the bearing of the hermetic compressor in the first embodiment The principal part expanded sectional view of the hermetic type compressor in Embodiment 1 Vertical section of a conventional hermetic compressor Main section enlarged sectional view of a conventional hermetic compressor Front view of a conventional hermetic compressor bearing

  According to the first aspect of the present invention, the lubricating oil is stored in the sealed container, and the electric element including the stator and the rotor, the electric element disposed below the electric element, and driven by the electric element. Containing a compression element, the compression element comprising a shaft having a main shaft portion to which an eccentric shaft portion and the rotor are fixed, a cylinder block having a compression chamber, a piston reciprocating in the compression chamber, and A thrust mechanism provided at the upper part of the bearing, further comprising: a coupling mechanism that couples the piston and the eccentric shaft portion; and a bearing that is provided in the cylinder block and supports the main shaft portion of the shaft. A thrust washer is provided between the surface and the rotor, an oil groove for discharging the lubricating oil is provided on the thrust surface, and a chamfered portion is provided on the inner diameter side of the thrust surface. Part of the one in which the cross-sectional area of the side away from the compression chamber than closer to the compression chamber side is formed to be larger.

  Thus, by increasing the cross-sectional area of the chamfered part on the opposite side to which the compressive load is applied, the sliding area on the side to which the compressive load is applied is ensured while ensuring the total cross-sectional area of the chamfered part, and the compressive load is applied. By reducing the sliding area on the non-side, high reliability and efficiency can be ensured.

  The invention according to claim 2 is the invention according to claim 1, wherein the shape of the chamfered portion is a two-step shape, and the inclination angle of the second step is larger than that of the first step.

  Accordingly, the cross-sectional area of the chamfered portion can be increased while ensuring the sliding area of the thrust surface and the inner diameter portion of the bearing, and therefore the lubricating oil can be stably discharged from the oil groove. In addition to the effect of the present invention, higher reliability can be ensured.

  The invention according to claim 3 is the invention according to claim 1 or 2, wherein the cross-sectional shape of the oil groove is formed such that the upper base length is equal to or greater than the lower base length.

  As a result, the cross-sectional area of the oil groove can be secured even when the machining allowance of the thrust surface is increased due to processing variations, so that the lubricating oil can be discharged from the oil groove stably, and the reliability is further increased. Sex can be secured.

  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 an enlarged sectional view of a main part of a thrust portion of the hermetic compressor according to Embodiment 1, and FIG. FIG. 4 is a front view of a bearing of the hermetic compressor in the first embodiment, and FIG. 5 is a front view of the bearing of the hermetic compressor in the first embodiment. It is a principal part expanded sectional view.

  1 to 5, an electric element 107 including a stator 103 and a rotor 105 and a compression element 109 that is rotationally driven by the electric element 107 are housed in a sealed container 101, and the bottom portion is lubricated. Oil 111 is stored. The electric element 107 and the compression element 109 are assembled together to form a compression mechanism 113, and the compression mechanism 113 is elastically supported in the sealed container 101 by a plurality of coil springs (not shown).

A cylindrical compression chamber 117 is formed in the cylinder block 115 constituting the compression element 109, and a piston 119 is fitted into the compression chamber 117 in a reciprocating manner. A bearing 121 is fixed to the upper part of the cylinder block 115, an oil groove 125 is provided in a part of the thrust surface 123 above the bearing 121, and a chamfered portion 127 is provided on the inner diameter side of the thrust surface 123. ing.

  The shaft 129 includes a main shaft portion 133 that is pivotally supported by the bearing 121 in the vertical direction and has a spiral oil supply groove 131 on the outer periphery thereof, and an eccentric shaft portion 135 formed therebelow. The piston 119 is connected by a connecting mechanism 137.

  Further, a pipe-shaped oil supply pipe 139 is press-fitted into an oil supply hole (not shown) formed at the lower end of the eccentric shaft portion 135, and one end of the oil supply pipe 139 opens into the lubricating oil 111, and one end extends from the oil supply hole. It communicates with the spiral oil supply groove 131.

  The electric element 107 includes a stator 103 fixed above the cylinder block 115 and a rotor 105 fixed to the main shaft portion 133 of the shaft 129 by shrink fitting or the like.

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

  When the electric element 107 is energized from an external power source (not shown), the rotor 105 rotates, and the shaft 129 rotates along with this, and the rotational movement of the eccentric shaft portion 135 is caused to move through the coupling mechanism 137 to the piston. 119. As a result, the piston 119 reciprocates in the compression chamber 117, and the compression element 109 performs a predetermined compression operation.

  As a result, the refrigerant gas is sucked into the compression chamber 117 from the cooling system (not shown), compressed, and then discharged again to the cooling system.

  Next, the oil supply path of the lubricating oil 111 stored at the bottom of the sealed container 101 will be described.

  The oil supply pipe 139 immersed in the lubricating oil 111 stored at the bottom of the hermetic container 101 pumps the lubricating oil 111 upward by centrifugal force, lubricates each sliding portion, and a part thereof is a spiral oil supply groove. 131 is further conveyed to the upper part. The conveyed lubricating oil 111 is stored in a chamfered portion 127 provided at the upper portion of the bearing 121, supplied to the thrust surface 123, and discharged through an oil groove 125 provided on the thrust surface 123.

  Thereafter, the lubricating oil 111 discharged to the outside of the bearing 121 is stored again at the bottom of the sealed container 101 by its own weight.

  Accordingly, if the cross-sectional area of the chamfered portion 127 and the oil groove 125 provided on the upper portion of the bearing 121 are reduced due to the variation in machining allowance of the thrust surface 123 disposed on the upper portion of the bearing 121, the chamfered portion 127 is reduced. The amount of the lubricating oil 111 that can be stored in the oil is reduced, and the amount of the lubricating oil 111 that is sent to the oil groove 125 is also reduced. Furthermore, since the cross-sectional area of the oil groove 125 is small, the amount of the lubricating oil 111 that can pass through the oil groove 125 is also reduced. Moreover, since the discharge amount of the lubricating oil 111 from the oil groove 125 decreases, the oil supply amount of the entire oil supply path decreases.

  Next, the horizontal load F2 and the load F3 due to the influence of the repulsive load F1 acting on the piston 119 will be described.

  The repulsive load F <b> 1 acting on the piston 119 is governed by the pressure in the compression chamber 117 and the inner diameter of the compression chamber 117, becomes maximum near the second half of the compression stroke, and acts greatly on the shaft 129 via the coupling mechanism 137.

  In the latter half of the compression stroke in which the maximum repulsive load F1 is generated, the eccentric shaft portion 135 is located on the compression chamber 117 side, and the repulsive load F1 acting on the piston 119 acts on the eccentric shaft portion 135 via the coupling mechanism 137. .

  Further, since a clearance of about 10 to 30 μm is set in the diameter of the main shaft portion 133 of the shaft 129 and the inner diameter of the shaft hole of the bearing 121, the shaft 129 is inclined. Along with this inclination, a repulsive load F1 acting on the eccentric shaft portion 135 causes a pressing load F2 to act on the lower side of the bearing 121 on the side far from the compression chamber 117 of the bearing 121. Along with this, a pressing load F3 acts on the upper side of the bearing 121 on the side close to the compression chamber 117 of the bearing 121, and a vertical load F4 acts on the thrust surface 123 on the side near the compression chamber 117. In addition, a load F4 of the weight of the rotor 105 and the shaft 129 acts on the thrust surface 123 disposed on the upper portion of the bearing 121 in the vertical direction.

  Therefore, a horizontal load F 2 acts on the lower side of the bearing 121 on the side far from the compression chamber 117, and a horizontal load F 3 acts on the upper side of the bearing 121 on the side closer to the compression chamber 117. Further, a vertical load F4 acts on the thrust surface 123 on the side closer to the compression chamber 117.

  Therefore, by increasing the chamfered portion 127 provided on the upper portion of the bearing 121, it is possible to avoid the chamfered portion 127 from becoming smaller due to variations in processing, and a stable oil supply amount can be ensured. Is increased, the sliding area on the bearing 121 where the horizontal load F3 is applied is reduced, and the sliding area of the thrust surface 123 on which the vertical load F4 is applied is also reduced. There was a possibility of lowering.

  Therefore, in the chamfered portion 127, the load F3 and the load F4 generated by the influence of the compression load acting on the piston 119 are applied, and the load F3 and the load F4 are not applied to the side closer to the compression chamber 117 than the compression chamber 117. By forming so that the cross-sectional area on the far side becomes larger, the total cross-sectional area of the chamfered portion 127 is secured, while the sliding area on the side receiving the load due to the effect of the compressive load is secured, and the influence of the compressive load Since the sliding area on the side not subjected to the pressure can be reduced, the amount of oil supply can be secured stably, the sliding loss can be reduced, and the reliability and efficiency of the hermetic compressor can be improved.

  In addition, the chamfered portion 127 has a two-stage shape, and the inclination angle of the second cut 143 with respect to the horizontal is larger than that of the first step 141, so that the sliding area of the upper portion of the bearing 121 and the sliding of the thrust surface 123 are increased. The cross-sectional area of the chamfered portion 127 can be further increased while securing the area. From this, it is possible to further improve the reliability of the hermetic compressor.

  Further, by forming the cross-sectional shape of the oil groove 125 so that the upper base length is equal to or greater than the lower base length, the cross-sectional area of the oil groove 125 can be reduced with respect to the variation in the machining allowance due to the processing of the thrust surface 123. The rate of change can be reduced. From this, the cross-sectional area of the oil groove 125 can be secured stably, the amount of oil supply can be secured more stably, and the reliability of the hermetic compressor can be achieved.

  In the first embodiment, the configuration in which the compression element 109 is disposed below the electric element 107 has been described. However, the hermetic compressor having the configuration in which the compression element 109 is disposed above the electric element 107 is described. The same action and effect can be expected.

As described above, the hermetic compressor according to the present invention reduces sliding loss while ensuring a stable amount of oil supply, and provides high reliability and efficiency, so that an air conditioner, a refrigerator-freezer, etc. It can be applied to refrigeration equipment.

DESCRIPTION OF SYMBOLS 101 Airtight container 103 Stator 105 Rotor 107 Electric element 109 Compression element 111 Lubricating oil 115 Cylinder block 117 Compression chamber 119 Piston 121 Bearing 123 Thrust surface 125 Oil groove 127 Chamfer 129 Shaft 133 Main shaft part 135 Eccentric shaft part 137 Connection mechanism

Claims (3)

The compression element stores lubricating oil in an airtight container, and includes an electric element having a stator and a rotor, and a compression element that is disposed below the electric element and driven by the electric element, A shaft having an eccentric shaft portion and a main shaft portion to which the rotor is fixed, a cylinder block having a compression chamber, a piston reciprocating in the compression chamber, and the piston and the eccentric shaft portion. And a coupling mechanism provided on the cylinder block and supporting the main shaft portion of the shaft, and further, between a thrust surface provided on an upper portion of the bearing and the rotor. A thrust washer is provided, an oil groove for discharging lubricating oil is provided on the thrust surface, a chamfered portion is provided on the inner diameter side of the thrust surface, and the chamfered portion is close to the compression chamber side. Hermetic compressor formed as the cross-sectional area of the side away from the compression chamber is greater than the side. 2. The hermetic compressor according to claim 1, wherein the chamfered portion has a two-stage shape and a larger second-stage inclination angle than the first stage. The hermetic compressor according to claim 1 or 2, wherein a cross-sectional shape of the oil groove is formed so that an upper base length is equal to or greater than a lower base length.