JP2009085125A - Hermetic compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hermetic compressor having a small sliding loss, high efficiency, and high reliability. <P>SOLUTION: Lubricating oil is collected in a sealed container. An electric element equipped with a stator and a rotor, and a compressing element driven by the electric element are stored in the sealed container. The compressing element comprises a crank shaft to which the rotor is foxed, and equipped with an oiling mechanism communicating into the lubricating oil at one end and supplying the lubricating oil to the compressing oil; a bearing portion forming a cantilever bearing by journaling a main shaft portion of the crank shaft; a cylinder block 105 equipped with a generally cylindrical compression chamber; and a piston reciprocating in the compression chamber. In a thrust sliding portion supporting a load in a gravity direction of the crank shaft or the rotor, a thrust non-sliding surface 152 which is a non-sliding portion is unevenly distributed, so that an area of the sliding surface is decreased and the sliding loss can be reduced. The lubricating oil can be easily supplied from the thrust non-sliding surface 152 to the thrust sliding surface 151 to reduce friction, and the hermetic compressor having high efficiency and high reliability can be provided. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a hermetic compressor mainly used for a household refrigerator or the like.

  In recent years, there has been an increasing demand for hermetic compressors with high efficiency in household refrigerators and the like from the viewpoint of energy saving. In addition, there is a great demand for a hermetic compressor with high efficiency, high reliability, and good productivity.

  As a conventional hermetic compressor, there is one for the purpose of improving the lubrication characteristics of a thrust sliding portion (see, for example, Patent Document 1).

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

  FIG. 18 is a longitudinal sectional view of a conventional hermetic compressor, and FIG. 19 is a cross-sectional view of a main part of a thrust sliding portion of the conventional hermetic compressor.

  The hermetic compressor 1 houses a compressor unit 6 in which an electric element 3 and a compression element 4 are integrated by a cylinder block 5 in a hermetic container 2. The crankshaft 7 is pivotally supported by the bearing portion 8 of the cylinder block 5, and the large end portion 11a of the connecting rod 11 is connected to the eccentric shaft 10 protruding from the flange 9 at the upper end, and the small end portion 11b is connected to the small end portion 11b. A piston 14 that slides in the compression chamber 13 is connected via a piston pin 12.

  The lower end surface of the flange 9 is a shaft thrust surface 15. Further, the upper end surface of the bearing portion 8 is a bearing portion thrust surface 16, and the shaft thrust surface 15 and the bearing portion thrust surface 16 constitute a thrust sliding portion 17.

  Lubricating oil 20 is stored at the bottom of the airtight container 2, and an oil supply cone 19 having a smaller diameter than the crankshaft 7 provided at the lower end of the crankshaft 7 opens into the lubricating oil 20.

  An in-shaft oil supply passage 23 is provided in the crankshaft 7, and an eccentric passage 18 is provided in the eccentric shaft 10, and an oil supply cone 19, an in-shaft oil supply passage 23, an eccentric passage 18 and the like are provided. Thus, the oil supply mechanism 24 is configured.

  An oil supply path 25 provided in the flange 9 of the crankshaft 7 communicates with the shaft thrust surface 15 from the upper end surface of the flange 9, and a tapered portion 21 is provided on the inner peripheral side of the bearing portion thrust surface 16. Yes.

  The electric element 3 is composed of a rotor 26 and a stator 27.

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

  When the stator 27 of the electric element 3 is energized, the rotor 26 and the crankshaft 7 to which the rotor 26 is fixed rotate. The rotation of the eccentric shaft 10 of the crankshaft 7 is converted into a reciprocating motion by the connecting rod 11, and the piston 14 reciprocates in the compression chamber 13 of the cylinder block 5 via the small end portion 11 b and the piston pin 12, and is compressed. Refrigerant gas is sucked and compressed by expanding and reducing the volume of the chamber 13.

  The load acting on the thrust sliding portion 17 via the connecting rod 11 and the eccentric shaft 10 is supported by the weight of the crankshaft 7 and the rotor 26 of the electric element 3 and the pressure received by the piston 14.

  Next, supply of lubricating oil to each sliding part such as the thrust sliding part 17 will be described.

  Lubricating oil 20 sucked up from an oil supply cone 19 provided on the crankshaft 7 is stored in a tapered portion 21 provided inside the bearing portion thrust surface 16 via an oil supply mechanism 24 such as an oil supply passage 23 in the shaft. .

  A part of the lubricating oil 20 stored in the tapered portion 21 is discharged into the sealed container 2 from holes (not shown) provided on the upper and side surfaces of the eccentric shaft 10, and is connected to the connecting rod 11 and the piston 14. The remaining lubricant 20 is supplied to the thrust sliding portion 17 by being scattered.

  In addition, the lubricating oil 20 that has fallen onto the flange 9 of the crankshaft 7 reaches the thrust sliding portion 17 through the oil supply path 25.

As described above, the lubricating oil 20 is supplied to the thrust sliding portion 17 as the crankshaft 7 rotates.
JP 2001-295766 A

  However, in the conventional configuration, in order to reduce the loss caused by the sliding of the shaft thrust surface 15 and the bearing portion thrust surface 16, the width of the shaft thrust surface 15 and the bearing portion thrust surface 16 in the centrifugal direction is reduced. If it is narrowed and the sliding area is reduced, the surface pressure increases and the wear of the thrust surface increases, and the thrust sliding portion 17 on the side of the anti-compression chamber 13 is particularly close to the top dead center where the pressure in the compression chamber 13 is high. Since a great amount of surface pressure acts, there is a problem that the wear of the shaft thrust surface 15 and the bearing portion thrust surface 16 on the anti-compression chamber 13 side is increased, and the reliability is improved while reducing the sliding loss. There is a problem that it is difficult to ensure.

  The present invention solves the above-described problems, and reduces the loss generated in the thrust sliding portion, suppresses wear that increases due to a compression load or a load such as a crankshaft, and reduces the sliding loss. An object of the present invention is to provide a hermetic compressor in which reliability is sufficiently ensured by increasing the efficiency and reducing wear of the thrust sliding portion 17.

  In order to solve the above-described conventional problems, a compressor according to the present invention stores lubricating oil in an airtight container, and houses an electric element having a stator and a rotor, and a compression element driven by the electric element. The compression element is supported by a crankshaft having a rotor fixed and an oil supply mechanism having one end communicating with the lubricating oil and supplying the compression element to the compression element, and a main shaft portion of the crankshaft. A thrust slide that supports a load in the direction of gravity of the crankshaft and the rotor, including a bearing portion that forms a cantilever bearing, a cylinder block that includes a substantially cylindrical compression chamber, and a piston that reciprocates in the compression chamber. The thrust non-sliding surface, which becomes the non-sliding part, is unevenly distributed in the part, the total area of the thrust sliding surface is reduced, sliding loss can be reduced, and the lubricating oil is not thrust non-sliding. From the moving surface Since it can be easily supplied to the thrust sliding surface and the load acting on the thrust sliding surface can be distributed appropriately, both the sliding loss reduction effect and the wear reduction effect on the thrust sliding surface can be reduced. It has the effect of preparing.

  The hermetic compressor of the present invention can be unevenly distributed in the thrust sliding portion so that the thrust load can be properly distributed and the sliding area can be reduced. It is possible to provide a hermetic compressor capable of improving reliability.

  According to the first aspect of the present invention, the lubricating oil is stored in a sealed container, and an electric element including a stator and a rotor, and a compression element driven by the electric element are accommodated, and the compression is performed. The element is supported by the crankshaft having an oil supply mechanism with one end communicating with the lubricating oil and supplying the lubricating oil to the compression element, and a main shaft portion of the crankshaft. And a cylinder block having a substantially cylindrical compression chamber, and a piston that reciprocates in the compression chamber. The load in the gravity direction of the crankshaft and the rotor is Thrust non-sliding surface that becomes non-sliding part is unevenly distributed in the supporting thrust sliding part, and it is unevenly distributed so that the load received by the thrust sliding surface can be properly distributed and the sliding area is reduced. Therefore, it is possible to achieve both the sliding loss reduction effect and the wear reduction effect at the thrust sliding part, and it is possible to achieve both high efficiency by reducing sliding loss and improved reliability by reducing wear. A hermetic compressor can be provided.

  According to a second aspect of the present invention, in the first aspect of the present invention, the thrust sliding portion includes a thrust sliding surface which is a sliding portion and a thrust non-sliding surface alternately in the circumferential direction. If the sliding area in the radial direction of the thrust sliding part is narrowed to reduce the sliding area, the sliding in the circumferential direction approaches line contact and accelerates wear, resulting in increased reliability. The thrust sliding surface and the non-thrust sliding surface are alternately arranged in the circumferential direction to reduce the sliding area of the thrust sliding portion, but the sliding in the circumferential direction approaches a line contact. Therefore, in addition to the effect of the first aspect of the invention, it is possible to achieve high efficiency by reducing sliding loss while ensuring reliability.

  The invention according to claim 3 of the present invention is the invention according to claim 1 or 2, wherein when the piston is in the vicinity of the top dead center, the thrust sliding portion is anti-compressed with respect to the axial center of the main shaft portion. When there is more thrust non-sliding surface on the compression chamber side than on the chamber side, and the piston is near top dead center, the crankshaft is tilted within the clearance with the bearing due to the compression load, and the crankshaft is bent. Therefore, in the thrust sliding part, a larger load acts on the sliding surface on the anti-compression chamber side than on the compression side, but there are few non-sliding surfaces on the anti-compression side so that there are many sliding surfaces. In addition to the effects of the invention according to claim 1 or 2, the surface pressure on the side of the non-compression chamber (load side) on which a large load acts is reduced to reduce wear and improve reliability. Securing and sliding loss Reduced, it is possible to secure and reliable high efficiency.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the thrust non-sliding surface communicates with an oil supply mechanism provided in the crankshaft. The lubricating oil is supplied in an abundant manner to the thrust non-sliding surface, and as a result, the lubricating oil is stably supplied to the thrust sliding portion, so that the effect of the invention according to any one of claims 1 to 3 is achieved. In addition, the lubrication state of the thrust sliding portion can be maintained well, and high reliability can be ensured.

  According to a fifth aspect of the present invention, in the invention according to any one of the first to fourth aspects, the step difference between the thrust sliding surface and the thrust non-sliding surface is in the range of 10 μm to 0.2 mm. Some of the lubricating oil supplied to and discharged from the thrust non-sliding surface can be reliably supplied to the thrust sliding surface for lubrication, and the remaining lubricating oil can be removed from the eccentric part of the crankshaft. From the upper end of the connecting rod and eccentric part through the pipe, it is supplied to the inner surface of the sealed container, the cylinder block, the piston, etc., so that the lubricating oil can be appropriately distributed and supplied to each sliding part. In addition to the effect of the invention according to any one of the items 4, the lubricating state of each sliding portion as well as the thrust sliding portion can be well maintained, and high reliability can be ensured.

  Further, when the step is in the range of 10 μ to 0.1 mm, the step can be provided by pressing, and when the step is in the range of 0.05 to 0.2 mm, the step can be formed by casting. Therefore, it is possible to form the non-sliding surface by a very simple method, and high productivity can be obtained.

  According to a sixth aspect of the present invention, in the invention according to any one of the first to fourth aspects, the lubricating oil reservoir portion to which the lubricating oil is supplied from the oil supply mechanism is formed in the cylinder block, and the thrust is Since at least a part of the sliding part is surrounded by the lubricating oil reservoir, and the lubricating oil is stored in the lubricating oil reservoir, at least a part of the thrust sliding part surrounded by the lubricating oil reservoir is Since it is always immersed in the lubricating oil, it is possible to prevent the lubricating oil from being depleted at the thrust sliding portion, and the thrust sliding portion is cooled by the lubricating oil, causing a local temperature rise. In addition to the effects of the invention according to any one of claims 1 to 4, it is possible to maintain the lubrication state of the thrust sliding portion satisfactorily. Ensure sufficiently high reliability Can.

  According to a seventh aspect of the present invention, in the invention according to any one of the first to sixth aspects, the position of the rotor in the axial direction is shifted with respect to the stator, and the magnetism generated in the rotor Supports at least part of the load in the gravitational direction of the crankshaft and the rotor with an attractive force. A magnetic attractive force acts between the rotor and the stator, and the rotor fixed to the crankshaft is perpendicular to the rotor. Since the force which pulls up acts, the load which acts on a thrust sliding part is reduced, and the surface pressure which acts on a thrust sliding part decreases, Therefore The invention of any one of Claim 1 to 6 In addition to the effect, it is possible to ensure reliability and reduce sliding loss, and to ensure high efficiency and high reliability.

  According to an eighth aspect of the present invention, in the invention according to any one of the first to seventh aspects, a C chamfer, an R chamfer, or an inclined crowning is formed at an edge of the thrust sliding portion. The lubricating oil can be smoothly and reliably supplied from the thrust non-sliding surface to the thrust sliding surface by C chamfering, R chamfering, or inclined crowning, according to any one of claims 1 to 7. In addition to the effects of the described invention, the lubrication state of the thrust sliding surface can be stabilized, reliability can be ensured, and sliding loss can be reduced.

  The invention according to claim 9 of the present invention is the invention according to any one of claims 1 to 8, wherein the thrust sliding surface is provided with a concave oil retaining portion for storing lubricating oil. The lubrication of the thrust sliding surface is ensured by the lubricating oil held in the recess until the lubricating oil reaches the thrust sliding surface, such as at the initial stage of starting the machine. In addition to the effects of the invention described above, the occurrence of wear is reduced even in severe conditions such as the initial stage of startup, and reliability can be ensured.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Further, 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 bottom view of a cylinder block in the hermetic compressor of the same embodiment, and FIG. FIG. 4 is a cross-sectional view taken along line AA of FIG. 3, FIG. 5 is a cross-sectional view of the main part of the hermetic compressor in the same embodiment, and FIG. It is principal part sectional drawing of the hermetic compressor in the form.

  7 is a characteristic diagram of the compressor input according to the embodiment, FIG. 8 is a characteristic diagram of the compressor input and the maximum wear amount according to the embodiment, and FIG. 9 is a hermetic compressor according to the embodiment. It is a characteristic view of the amount of oil supply in.

  1 to 6, the hermetic compressor houses a compressor unit 106 in which an electric element 103 and a compression element 104 are integrated in a cylinder block 105 in a hermetic container 102.

  The crankshaft 107 is pivotally supported by the bearing portion 108 of the cylinder block 105, and the large end portion 111a of the connecting rod 111 is connected to the eccentric shaft 110 protruding from the flange 109 at the upper end, and the small end portion 111b is connected to the small end portion 111b. A piston 114 that slides in the compression chamber 113 is connected via a piston pin 112.

  The lower end surface of the flange 109 is a shaft thrust surface 115. The upper end surface of the bearing portion 108 is a bearing portion thrust surface 116, and the shaft thrust surface 115 and the bearing portion thrust surface 116 constitute a thrust sliding portion 117.

  Lubricating oil 120 is stored at the bottom of the sealed container 102, and an oil supply cone 119 having a smaller diameter than the crankshaft 107 provided at the lower end of the crankshaft 107 is opened in the lubricating oil 120.

  An in-shaft oil supply passage 123 is provided in the crankshaft 107, and an eccentric passage 118 is provided in the eccentric shaft 110. The oil supply cone 119, the in-shaft oil supply passage 123, the eccentric passage 118, etc. Thus, the oil supply mechanism 124 is configured. A tapered portion 121 is provided on the inner peripheral side of the bearing portion thrust surface 116.

  The rotor 126 is fixed to the main shaft portion 140 of the crankshaft 7 by a method such as press fitting or shrink fitting. The stator 127 generates a rotating magnetic field when the winding 141 is energized, and rotates the rotor 126.

  The weights of the crankshaft 107 and the rotor 126 are received by a thrust sliding portion 117 composed of a shaft thrust surface 115 and a bearing portion thrust surface 116.

  The thrust sliding portion 117 is formed by thrust sliding surfaces 151 and thrust non-sliding surfaces 152 that are alternately arranged in the circumferential direction. In the present embodiment, the thrust non-sliding surface 152 is formed on the bearing portion thrust surface 116 side. The thrust non-sliding surface 152 is formed so that the compression chamber 113 side is larger than the axial center of the main shaft portion 140. The thrust non-sliding surface 152 is in communication with an oil supply mechanism 124 provided on the crankshaft 107 and an upper end portion 156 of the spiral groove 155.

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

  When the winding 141 of the stator 127 is energized, the rotor 126 and the crankshaft 107 are rotated by the generation of the rotating magnetic field. Due to the rotation of the crankshaft 107, the eccentric motion of the eccentric shaft 110 is converted into a linear motion via the connecting rod 111, and the piston 114 sucks and compresses the refrigerant gas in the compression chamber 113.

  The crankshaft 107 receives the weight of the crankshaft 107, the rotor 126, and the like at the thrust sliding portion 117.

  Further, when the piston 114 is compressed toward the top dead center, the piston 114 receives a large pressure of the refrigerant gas, particularly in the vicinity of the top dead center. The thrust sliding portion 117 receives the contact with the contact portion of the bearing portion 108.

  The load received by the thrust sliding portion 117 is that the eccentric shaft 110 side is inclined to the anti-compression chamber 113 side in the clearance between the main shaft portion 140 of the crankshaft 107 and the bearing portion 108. A larger load is applied to the counter compression chamber 113 side.

  The thrust sliding portion 117 receives a load due to supporting the weight of the crankshaft 107 and the rotor 126 and a load due to the pressure of the refrigerant gas received by the piston 114, and a sliding loss occurs in the thrust sliding portion 117. .

  In order to reduce the sliding loss, the area of the thrust sliding portion 117 may be reduced. However, when the area is reduced by reducing the radial width of the thrust sliding portion 117, the thrust sliding portion 117 is reduced. Approaches line contact.

  At this time, the load applied by the pressure of the refrigerant gas is received by the thrust sliding portion 117 having a very narrow width, and the surface pressure becomes very high. Further, since the width of the thrust sliding portion 117 is narrowed, it is difficult to form an oil film, and a partial oil film breakage causes a closer to a linear contact state.

  However, since the thrust sliding portion 117 having the configuration of the present embodiment forms the thrust sliding surface 151 and the thrust non-sliding surface 152 alternately in the circumferential direction, the radial width can be increased. Yes, it will not be in line contact.

  Further, since there are a plurality of thrust non-sliding surfaces 152 in the circumferential direction, the lubricating oil 120 flowing out to the thrust non-sliding surface 152 is more easily supplied to the thrust sliding surface 151 and oil film formation is facilitated. It is possible to prevent stranded contact, and to reduce the oil film breakage of the thrust sliding portion 117.

  Further, the thrust non-sliding surface 152 has more thrust non-sliding surfaces 152 on the compression chamber 113 side than thrust non-sliding surfaces 152 on the anti-compression chamber 113 side with respect to the plane 160 passing through the axis of the bearing portion 108. Since the thrust sliding surface 151 on the side of the anti-compression chamber 113 can be kept sufficiently large, the thrust load on the side of the anti-compression chamber 113 generated when the piston 114 compresses the refrigerant gas is provided. It can be received with a low surface pressure, and it is possible to achieve both high efficiency and ensuring reliability by reducing sliding loss.

  FIG. 7 shows a state where the thrust non-sliding surface 152 is not provided, that is, the area ratio of the thrust sliding surface 151 is 100%, and machining is added to the same cylinder block 105 as shown in FIG. According to the specifications, the thrust non-sliding surface 152 is provided in stages, and the maximum non-sliding surface 152 of the thrust, that is, the area ratio of the thrust sliding surface 151 is changed to 40%, and the compressor capacity is actually measured. It is the characteristic figure of the compressor input with respect to the thrust sliding area ratio which showed the relationship with a result.

  In addition, since there was some variation in the capacity of the actually measured compressor, the input is converted and graphed so that the capacity becomes constant.

  As can be seen from FIG. 7, as the thrust sliding surface 151 decreases, the sliding loss decreases, so the compressor input decreases, and the thrust sliding area ratio decreases to about 50%. Yes.

  FIG. 8 shows the specifications as shown in FIG. 3, and the ratio between the thrust non-sliding surface 152 and the thrust sliding surface 151 is fixed to 50%, and then the formation of the thrust non-sliding surface 152 is anti-compressed. When the chamber 113 side and the compression chamber 113 side are set to the same 50%, the ratio of the thrust non-sliding surface 152 on the compression chamber 113 side is increased to 80%, and the relationship with the actually measured compressor input is indicated by a solid line. It is the characteristic view which showed the maximum wear amount with the dotted line (approximation line) from the measurement result of the maximum wear amount of the thrust sliding surface 151 on reliability test conditions while showing with (approximate line).

  From FIG. 8, by forming the thrust non-sliding surface 152 around 70% on the compression chamber 113 side, the wear amount of the thrust sliding surface 151 can be minimized, and the slide that can be evaluated by the compressor input can be minimized. It can be confirmed that the dynamic loss is minimized by forming the thrust non-sliding surface 152 around 65% on the compression chamber 113 side.

  From the viewpoint of both minimizing the compressor input and reducing the amount of wear, the thrust non-sliding surface 152 is formed on the compression chamber 113 side in the range of 55% to 75%, more optimally 65 to 70%. This is optimal from the viewpoint of improving efficiency by reducing input loss and improving reliability by reducing the amount of wear on the thrust sliding surface 151.

  Next, the relationship between the oil supply to the thrust sliding surface 151, the oil supply to each sliding portion such as the eccentric shaft 110, the connecting rod 111, and the piston 114 of the crankshaft 107, and the depth of the thrust non-sliding surface 152. Will be described.

  FIG. 9 is a characteristic diagram showing the depth of the thrust non-sliding surface 152 with respect to the thrust sliding surface 151 and the amount of lubrication oil 120 supplied to each part.

  Each part includes the amount of outflow from the thrust sliding portion 117, the amount of outflow from the eccentric shaft 110 of the crankshaft 107 and the connecting rod 111, and the oil supply hole (not shown) inside the connecting rod 111, This is the amount of outflow from the upper end of the eccentric shaft 110.

  The lubricating oil 120 flowing out from the thrust sliding portion 117 is used for lubrication of the thrust sliding portion 117 and cooling of the cylinder block 105, and the lubricating oil 120 flowing out from the gap between the connecting rod 111 and the eccentric shaft 110 is connected to the thrust sliding portion 117. Lubricating oil 120 that is used to lubricate the rod 111 and the eccentric shaft 110 and flows out from the upper end of the eccentric shaft 110 is used to lubricate and cool the compression chamber 113 and the piston 114 of the cylinder block 105. Used to reduce wear and improve performance and reliability by cooling.

  It has been found by the inventors that the lubricating oil 120 supplied to the periphery of the thrust sliding portion 117 and the piston 114 should be approximately 30 ml / min or more. The depth is suitably set from 10 μm to 0.2 mm.

  For example, when it is desired to cool the periphery of the piston 114 and the compression chamber 113 intensively, the depth of the thrust non-sliding surface 152 can be reduced within the above range in order to reduce the outflow from the thrust sliding portion 117. Good.

  The appropriate value of the depth of the thrust non-sliding surface 152 is also related to the processing method.

  When the step (depth) of the thrust non-sliding surface 152 is in the range of 10 μm to 0.1 mm, the method of forming the thrust non-sliding surface 152 by pressing the thrust non-sliding surface 152 is easy.

  When the step (depth) of the thrust non-sliding surface 152 is in the range of 0.05 mm to 0.2 mm, an appropriate step is formed on the thrust non-sliding surface 152 at the manufacturing stage of castings, aluminum alloys, etc. When finishing the sliding surface 151, a method of processing in the range of 0.05 mm to 0.2 mm is easy.

  Any of the methods does not require a special processing man-hour for forming the thrust non-sliding surface 152, so that the productivity is very good.

  Next, the oil supply to the thrust sliding part 117 is demonstrated.

  As described above, the crankshaft 107 is formed with the oil supply mechanism 124 including the oil supply cone 119, the oil supply passage 123 in the shaft, the spiral groove 155, the eccentric passage 118, and the like from below, and the upper end 156 of the spiral groove 155. Is in communication with the thrust non-sliding surface 152 via the tapered portion 121, and the guided lubricating oil 120 flows out of the thrust non-sliding surface 152.

  The lubricating oil 120 supplied to the thrust non-sliding surface 152 is continuously and stably supplied to the thrust sliding surface 151 by the rotation of the thrust sliding portion 117, and the oil film formation on the thrust sliding surface 151 is stabilized. , Improve reliability.

  Next, specifications for further stabilizing the oil supply to the thrust sliding portion 117 will be described.

  In particular, from the viewpoint of reducing sliding loss, when the low-viscosity lubricating oil 120 is used, the lower the viscosity is, the more easily the lubricating oil 120 evaporates, and local parts generated by partial metal contact at each sliding part. As the temperature rises, the possibility of local exhaust of the lubricating oil 120 increases.

  Also, if the supply of the lubricating oil 120 is insufficient and the cooling of the thrust sliding portion 117 is insufficient, the temperature of the thrust sliding portion 117 rises, and the adverse effect of sliding lubrication due to excessive decrease in the viscosity of the lubricating oil 120 may occur. There is also sex.

  In response to these problems, the lubricating oil reservoir 165 is always formed in the cylinder block 105 so that the lubricating oil 120 is accumulated in the vicinity of the thrust sliding surface 151 of the thrust sliding portion 117. Thus, the lubricating oil 120 is held, the lubricating oil 120 is always supplied to the thrust sliding portion 117, and the thrust sliding portion 117 is cooled.

  Further, since the thrust non-sliding surface 152 of the thrust sliding portion 117 is always filled with the lubricating oil 120, the supply of the lubricating oil 120 to the thrust sliding surface 151 is also stable.

  Further, as described above, even when the step of the thrust non-sliding surface 152 is reduced and the amount of oil supplied from the thrust sliding portion 117 (the amount of outflow of the lubricating oil 120) is reduced, the lubricating oil 120 is stably As a result, high efficiency and improved reliability can be obtained by reducing sliding loss.

  Further, since the lubricating oil reservoir 165 may be formed when the cylinder block 105 is cast, the productivity is very good.

  Further, since the chamfered portion 170 is formed at the edge of the thrust sliding surface 151 constituting the thrust sliding portion 117, the supply of the lubricating oil 120 from the thrust non-sliding surface 152 to the thrust sliding surface 151 is as follows. Since it becomes smoother, the lubrication state of the thrust sliding surface 151 becomes more stable, and the effect of reducing the sliding loss and improving the reliability can be further improved.

  As described above, the hermetic compressor according to the first embodiment can achieve high efficiency by reducing sliding loss, has little wear on the thrust sliding surface, is highly reliable, and has extremely high productivity. good.

  In the first embodiment, the thrust non-sliding surface 152 is formed on the bearing thrust surface 116. However, the thrust non-sliding surface 152 is formed on the shaft thrust surface 115 based on the same idea. Even if the thrust non-sliding surface 152 is formed on both the bearing thrust surface 116 and the shaft thrust surface 115 based on the same idea, the same effect can be obtained.

(Embodiment 2)
FIG. 10 is a longitudinal sectional view of a hermetic compressor according to the second embodiment of the present invention, FIG. 11 is a bottom view of a cylinder block in the hermetic compressor of the same embodiment, and FIG. 12 is a diagram of the same embodiment. The principal part enlarged view of a hermetic compressor, Drawing 13 is a longitudinal section of the hermetic compressor in the embodiment, and Drawing 14 is a characteristic figure showing magnetic thrust and compressor input in the embodiment.

  10 to 14, the hermetic compressor houses a compressor unit 206 in which an electric element 203 and a compression element 204 are integrated by a cylinder block 205 in a hermetic container 202.

  The crankshaft 207 is pivotally supported by the bearing portion 208 of the cylinder block 205, and the large end portion 211a of the connecting rod 211 is connected to the eccentric shaft 210 protruding from the flange 209 at the upper end, and the small end portion 211b is connected to the small end portion 211b. A piston 214 that slides in the compression chamber 213 is connected via a piston pin 212.

  The lower end surface of the flange 209 is a shaft thrust surface 215. The upper end surface of the bearing portion 208 is a bearing portion thrust surface 216, and the shaft thrust surface 215 and the bearing portion thrust surface 216 constitute a thrust sliding portion 217.

  Lubricating oil 220 is stored at the bottom of the sealed container 202, and an oil supply cone 219 having a smaller diameter than the crankshaft 207 provided at the lower end of the crankshaft 207 opens into the lubricating oil 220.

  An in-shaft oil supply passage (not shown) is provided in the crankshaft 207, and an eccentric passage 218 is provided in the eccentric shaft 210, and an oil supply cone 219, an in-shaft oil supply passage (not shown). The oil supply mechanism 224 is configured by the eccentric passage 218 and the like.

  The rotor 226 is fixed to the main shaft portion 240 of the crankshaft 207 by a method such as press fitting or shrink fitting. The stator 227 generates a rotating magnetic field by energizing the winding 241 and rotates the rotor 226. The weights of the crankshaft 207, the rotor 226, and the like are received by a thrust sliding portion 217 including a shaft thrust surface 215 and a bearing portion thrust surface 216.

  The thrust sliding portion 217 is formed of thrust sliding surfaces 251 and thrust non-sliding surfaces 252 that are alternately arranged in the circumferential direction. In the present embodiment, the thrust non-sliding surface 252 is formed on the bearing portion thrust surface 216 side. The thrust non-sliding surface 252 is formed so that the compression chamber 213 side is larger than the axial center of the main shaft portion 240. The thrust non-sliding surface 252 communicates with an oil supply mechanism 224 provided on the crankshaft 207 at the upper end portion of the spiral groove 255.

  In FIG. 13, 270 indicates the magnetic center line of the stator 227, and 271 indicates the magnetic center line of the rotor 226.

  The dimension H in the height direction is the difference between the magnetic center line 270 of the stator 227 and the magnetic center line 271 of the rotor 226. The magnetic center of the rotor 226 is perpendicular to the stator 227 by the dimension H (thrust). (Below the direction of load action).

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

  When the winding 241 of the stator 227 is energized, the rotor 226 and the crankshaft 207 are rotated by the generation of the rotating magnetic field. Due to the rotation of the crankshaft 207, the eccentric motion of the eccentric shaft 210 is converted into a linear motion via the connecting rod 211, and the piston 214 sucks and compresses the refrigerant gas in the compression chamber 213.

  The crankshaft 207 receives the weight of the crankshaft 207, the rotor 226, and the like at the thrust sliding portion 217.

  Further, when the piston 214 is compressed toward the top dead center, the piston 214 receives a large pressure of the refrigerant gas, particularly in the vicinity of the top dead center, and this pressure is finally applied to the main shaft portion 240 of the crankshaft 207. The thrust sliding portion 217 receives the contact with the contact portion of the bearing portion 208.

  The load received by the thrust sliding portion 217 is such that the eccentric shaft 210 side is inclined to the anti-compression chamber 213 side in the clearance between the main shaft portion 240 of the crankshaft 207 and the bearing portion 208, so that the axial center of the main shaft portion 240 is A larger load acts on the side of the anti-compression chamber 213.

  The thrust sliding portion 217 receives a load due to supporting the weight of the crankshaft 207 and the rotor 226 and a load due to the pressure of the refrigerant gas received by the piston 214, and a sliding loss occurs at the thrust sliding surface 217. .

  In order to reduce the sliding loss, the area of the thrust sliding portion 217 may be reduced. However, when the area is reduced by reducing the width of the thrust sliding portion 217 in the centrifugal direction, the thrust sliding portion 217 is reduced. Approaches line contact.

  At this time, the load applied by the pressure of the refrigerant gas is received by the thrust sliding portion 217 having a very narrow width, and the surface pressure becomes very high. Further, since the width of the thrust sliding portion 217 is narrowed, it is difficult to form an oil film, and when the oil film is partially cut, it becomes closer to a line contact state.

  However, since the thrust sliding portion 217 having the configuration of the present embodiment forms the thrust sliding surface 251 and the thrust non-sliding surface 252 alternately in the circumferential direction, the radial width can be increased. Yes, it will not be in line contact.

  Further, since there are a plurality of thrust non-sliding surfaces 252 in the circumferential direction, the lubricating oil 220 flowing out to the thrust non-sliding surface 252 is more easily supplied to the thrust sliding surface 251 and oil film formation is facilitated. It is possible to prevent stranded contact, and to reduce the oil film breakage of the thrust sliding portion 217.

  Further, the thrust non-sliding surface 252 has more thrust non-sliding surfaces 252 on the compression chamber 213 side than thrust non-sliding surfaces 252 on the anti-compression chamber 213 side with respect to the plane 260 passing through the axis of the bearing 208. Since the thrust sliding surface 251 on the side of the anti-compression chamber 213 can be kept sufficiently wide, the thrust load on the side of the anti-compression chamber 213 generated when the piston 214 compresses the refrigerant gas. Can be received at a low surface pressure, and it is possible to achieve both high efficiency and reliability by reducing sliding loss.

  The magnetic center line 271 of the rotor 226 is configured to be in a range (dimension H) of about 0.5 mm to 2 mm vertically below the magnetic center line 270 of the stator 227. A vertically upward force is applied from the stator 227.

  In FIG. 14, the horizontal axis represents the deviation (dimension H) between the magnetic center line 271 of the rotor 226 and the magnetic center line 270 of the stator 227, and the vertical axis represents the magnetic center line 271 of the rotor 226 and the stator 227. The magnetic center deviation (the gravity direction is positive) due to the deviation from the magnetic centerline 270 of the motor and the input of the hermetic compressor based on the actual measurement results of the inventors etc. is taken as the vertical axis, the deviation of the magnetic center and the theoretical thrust, input It is the graph which showed this relationship.

  The dimension H is positive when the magnetic center line of the rotor 226 is vertically above the magnetic center line of the stator 227.

  When this magnetic thrust is negative, it acts as a force that supports the gravity of the rotor 226 and the crankshaft 207.

  Further, the thrust sliding portion 217 having the specifications shown in FIG. 12 is used for actual measurement of the input of the hermetic compressor, and the area ratio of the thrust sliding surface 251 and the thrust non-sliding surface 252 is the same 50%. The area ratio of the thrust non-sliding surface 252 on the compression chamber 213 side to the area of the thrust non-sliding surface 252 is set to 65%, and the depth of the thrust non-sliding surface 252 is set to 0.05 mm.

  As can be seen from FIG. 14, a large input reduction effect is obtained when the dimension H is in the range of −0.5 mm or less.

  However, although not shown, it is known that when the magnetic center is set to -2 mm or less, the efficiency of the electric element 203 deteriorates due to the shift of the magnetic center, and the input increases conversely. It is desirable to set in the range of 5 mm.

  As described above, in the thrust sliding portion 217, the thrust sliding surface 251 and the thrust non-sliding surface 252 are formed to be unevenly distributed, and the rotor 226 is further shifted in the axial direction to thereby rotate the rotor. A magnetic thrust (magnetic attractive force) is applied to 226, and a part of the load in the gravity direction such as the gravity of the rotor 226 and the crankshaft 207 can be supported by this magnetic thrust.

  Therefore, the load acting on the sliding surface of the thrust sliding portion 217 can be reduced, the efficiency can be improved due to the input reduction effect of the compressor, and the reliability of the thrust sliding portion 217 can be improved.

  Further, shifting the magnetic centers of the rotor 226 and the stator 227 can be easily performed without adding parts, and the productivity is good.

(Embodiment 3)
FIG. 15 is a longitudinal sectional view of a hermetic compressor according to the third embodiment of the present invention, FIG. 16 is a bottom view of a cylinder block in the hermetic compressor of the same embodiment, and FIG. It is a principal part enlarged view of a hermetic compressor.

  In addition, the arrow shown in FIG. 17 has shown the rotation direction of the shaft thrust surface 315 facing the bearing part thrust surface 316. FIG.

  15 to 17, the hermetic compressor accommodates a compressor unit 306 in which an electric element 303 and a compression element 304 are integrated in a cylinder block 305 in a hermetic container 302.

  The crankshaft 307 is pivotally supported by the bearing portion 308 of the cylinder block 305, the large end portion 311a of the connecting rod 311 is connected to the eccentric shaft 310 protruding from the flange 309 at the upper end, and the small end portion 311b is A piston 314 that slides in the compression chamber 313 is connected via a piston pin 312.

  The lower end surface of the flange 309 is a shaft thrust surface 315. Further, the upper end surface of the bearing portion 308 is a bearing portion thrust surface 316, and the shaft thrust surface 315 and the bearing portion thrust surface 316 constitute a thrust sliding portion 317.

  Lubricating oil 320 is stored at the bottom of the sealed container 302, and an oil supply cone 319 having a smaller diameter than the crankshaft 307 provided at the lower end of the crankshaft 307 opens into the lubricating oil 320.

  The crankshaft 307 is provided with an in-shaft oil supply passage (not shown), and the eccentric shaft 310 is provided with an eccentric passage 318. An oil supply cone 319 and an in-shaft oil supply passage (not shown) are provided. The oil supply mechanism 324 is constituted by the eccentric passage 318 and the like.

  The rotor 326 is fixed to the main shaft portion 340 of the crankshaft 307 by a method such as press fitting or shrink fitting. The stator 327 generates a rotating magnetic field by energizing the winding 341 and rotates the rotor 326. The weights of the crankshaft 307, the rotor 326, and the like are received by a thrust sliding portion 317 including a shaft thrust surface 315 and a bearing portion thrust surface 316.

  The thrust sliding portion 317 is formed of thrust sliding surfaces 351 and thrust non-sliding surfaces 352 that are alternately arranged in the circumferential direction. In the present embodiment, the thrust non-sliding surface 352 is formed on the bearing portion thrust surface 316 side. The thrust non-sliding surface 352 is formed so that the compression chamber 313 side is larger than the axial center of the main shaft portion 340. The thrust non-sliding surface 352 communicates with the oil supply mechanism 324 provided on the crankshaft 307 at the upper end portion of the spiral groove 355.

  The thrust sliding surface 351 is formed with a recessed oil retaining portion 361, and the oil retaining portion 361 includes an introduction groove 363 and a reservoir portion 362.

  The introduction groove 363 of the oil retaining portion 361 opens in the counter-rotating direction of the shaft thrust surface 315 that is a counterpart member that slides and communicates with the reservoir portion 362.

  Further, the oil retaining portion 361 is formed by pressing or the like, and the depth is formed in the range of 10 μm to 0.1 mm.

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

  When the winding 341 of the stator 327 is energized, the rotor 326 and the crankshaft 307 are rotated by the generation of the rotating magnetic field. By the rotation of the crankshaft 307, the eccentric motion of the eccentric shaft 310 is converted into a linear motion via the connecting rod 311, and the piston 314 performs the suction and compression of the refrigerant gas in the compression chamber 313.

  The crankshaft 307 receives the weight of the crankshaft 307, the rotor 326, and the like at the thrust sliding portion 317.

  Further, when the piston 314 is compressed toward the top dead center, the piston 314 receives a large pressure of the refrigerant gas, particularly in the vicinity of the top dead center, but this pressure is finally reduced by the main shaft portion 340 of the crankshaft 307. The thrust sliding portion 317 receives the contact with the contact portion of the bearing portion 308.

  The load received by the thrust sliding portion 317 is such that the main shaft portion 340 of the crankshaft 307 is inclined to the anti-compression chamber 313 side in the clearance with the bearing portion 308, so that the axial center of the main shaft portion 340 is A larger load is applied to the anti-compression chamber 313 side.

  The thrust sliding portion 317 receives a load due to supporting the weight of the crankshaft 307 and the rotor 326 and a load due to the pressure of the refrigerant gas received by the piston 314, and a sliding loss occurs on the thrust sliding surface 317. .

  In order to reduce the sliding loss, the area of the thrust sliding portion 317 may be reduced. However, when the area is reduced by reducing the width of the thrust sliding portion 317 in the centrifugal direction, the thrust sliding portion 317 is reduced. Approaches line contact.

  At this time, the load applied by the pressure of the refrigerant gas is received by the thrust sliding portion 317 having a very narrow width, and the surface pressure becomes very high. Further, since the width of the thrust sliding portion 317 becomes narrower, it becomes difficult to form an oil film, and when the oil film is partially cut, it becomes closer to a line contact state.

  However, the thrust sliding portion 317 having the configuration of the present embodiment forms the thrust sliding surface 351 and the thrust non-sliding surface 352 alternately in the circumferential direction, so that the radial width can be increased. Yes, but not line contact.

  Further, since there are a plurality of thrust non-sliding surfaces 352 in the circumferential direction, the lubricating oil 320 that has flowed out to the thrust non-sliding surface 352 is more easily supplied to the thrust sliding surface 351, and oil film formation is facilitated. It is possible to prevent stranded contact, and to reduce the oil film breakage of the thrust sliding portion 317.

  Furthermore, the thrust non-sliding surface 352 has more thrust non-sliding surfaces 352 on the compression chamber 313 side than thrust non-sliding surfaces 352 on the anti-compression chamber 313 side with respect to the plane 360 passing through the axis of the bearing portion 308. Since the thrust sliding surface 351 on the side of the anti-compression chamber 313 can be kept sufficiently wide, the thrust load on the side of the anti-compression chamber 313 generated when the piston 314 compresses the refrigerant gas. Can be received at a low surface pressure, and it is possible to achieve both high efficiency and reliability by reducing sliding loss.

  Further, the lubricating oil that lubricates the thrust sliding surface 351 flows in the rotational direction due to viscous resistance as the crankshaft 307 rotates. Since the thrust sliding surface 351 has an introduction groove 363 that opens in the counter-rotating direction of the shaft thrust surface 315 that is a counterpart member that slides, the lubricating oil 320 flows from the introduction groove 363 into the reservoir portion 362 and accumulates. Oil is retained in the portion 362.

  As a result, the lubricating oil 320 is always held in the oil retaining portion 361 of the thrust sliding surface 352, and especially at the initial stage of starting the hermetic compressor, the lubricating oil 320 on the bottom surface of the hermetic container 302 is provided by the oil supply mechanism 324 of the crankshaft 307. Until the thrust sliding surface 351 reaches the thrust sliding surface 351, the lubricating oil 320 held in the reservoir portion 362 ensures the lubrication of the thrust sliding surface 351, and the occurrence of wear is reduced even in a severe state at the beginning of startup. Reliability can be ensured.

  Note that the oil retaining portion 361 having the introduction groove 363 and the reservoir portion 362 has a surface area with respect to the thrust load greatly increased on the thrust sliding surface 351 by providing the thrust sliding surface 351 with a greatly reduced area. Never do.

  As described above, since the compressor according to the present invention can achieve both high efficiency and high reliability, it can also be applied to a hermetic compressor used in an air conditioner, a refrigerator-freezer, and the like.

1 is a longitudinal sectional view of a hermetic compressor according to Embodiment 1 of the present invention. Bottom view of cylinder block in hermetic compressor of the embodiment The principal part enlarged view of the hermetic type compressor in the embodiment Sectional drawing in the AA line of FIG. Sectional drawing of the principal part of the hermetic compressor in the same embodiment Sectional drawing of the principal part of the hermetic compressor in the same embodiment Characteristic diagram of compressor input in hermetic compressor of the embodiment Characteristic diagram of compressor input and maximum wear in the hermetic compressor of the same embodiment Characteristics diagram of oil supply amount in hermetic compressor of the same embodiment Vertical sectional view of a hermetic compressor according to Embodiment 2 of the present invention Bottom view of cylinder block in hermetic compressor of the embodiment The principal part enlarged view of the hermetic type compressor in the embodiment Vertical sectional view of a hermetic compressor in the same embodiment Characteristic chart showing magnetic thrust and compressor input in hermetic compressor of the same embodiment Vertical sectional view of a hermetic compressor according to Embodiment 3 of the present invention Bottom view of cylinder block in hermetic compressor of the embodiment The principal part enlarged view of the hermetic type compressor in the embodiment Vertical section of a conventional hermetic compressor Cross section of the main part of the thrust sliding part of a conventional hermetic compressor

Explanation of symbols

102, 202, 302 Sealed container 103, 203, 303 Electric element 104, 204, 304 Compression element 105, 205, 305 Cylinder block 107, 207, 307 Crankshaft 108, 208, 308 Bearing part 113, 213, 313 Compression chamber 114 , 214, 314 Piston 117, 217, 317 Thrust sliding portion 120, 220, 320 Lubricating oil 124, 224, 324 Lubrication mechanism 126, 226, 326 Rotor 127, 227, 327 Stator 140, 240, 340 Main shaft portion 151 , 251, 351 Thrust sliding surface 152, 252, 352 Thrust non-sliding surface 165 Lubricating oil reservoir 361 Oil retaining portion

Claims (9)

  The lubricating oil is stored in a sealed 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 is fixed to the rotor, A crankshaft provided with an oil supply mechanism in which one end communicates with the lubricating oil and supplies the lubricating oil to the compression element; and a bearing portion that forms a cantilever bearing by pivotally supporting the main shaft portion of the crankshaft; A non-sliding portion is provided on a thrust sliding portion that includes a cylinder block having a substantially cylindrical compression chamber and a piston that reciprocates in the compression chamber, and supports a load in the gravity direction of the crankshaft and the rotor. A hermetic compressor in which the non-sliding thrust surface is unevenly distributed.   2. The hermetic compressor according to claim 1, wherein the thrust sliding portion includes a thrust sliding surface and a thrust non-sliding surface which are sliding portions arranged alternately in a circumferential direction.   The thrust sliding portion provided with more thrust non-sliding surfaces on the compression chamber side than on the non-compression chamber side in the thrust sliding portion when the piston is near the top dead center position. 2. The hermetic compressor according to 2.   The hermetic compressor according to any one of claims 1 to 3, wherein the thrust non-sliding surface communicates with an oil supply mechanism provided in the crankshaft.   The hermetic compressor according to any one of claims 1 to 4, wherein a step between the thrust sliding surface and the non-thrust sliding surface is in a range of 10 µm to 0.2 mm.   The lubricating oil reservoir portion to which lubricating oil is supplied from the oil supply mechanism is formed in the cylinder block, and at least a part of the thrust sliding portion is surrounded by the lubricating oil reservoir portion. The hermetic compressor described in 1.   The position of the rotor in the axial center direction is shifted with respect to the stator, and at least a part of the load in the gravity direction of the crankshaft and the rotor is supported by a magnetic attractive force generated in the rotor. The hermetic compressor according to claim 1.   The hermetic compressor according to any one of claims 1 to 7, wherein a C chamfer, an R chamfer, or an inclined crowning is formed at an edge of the thrust sliding portion.   The hermetic compressor according to any one of claims 1 to 8, wherein an oil retaining portion for storing lubricating oil is recessed in the thrust sliding surface.