JP5945683B2 - Hermetic compressor and refrigeration apparatus provided with the same - Google Patents

Description

  The present invention relates to an improvement in a bearing of a hermetic compressor.

  In recent years, due to demands for the global environment, household refrigerators and air conditioners are increasingly moving toward energy saving.

  As a conventional hermetic compressor, there is one that has an oil supply mechanism including a concentric hole or the like provided in a main shaft portion, thereby increasing the supply amount of lubricant and improving the lubrication performance (see, for example, Patent Document 1). . In addition, in order to prevent the cantilever bearing from coming into contact with each other, there is one provided with an inclined portion in which the diameter of the main shaft surface that slides with the end portion of the bearing is reduced (see, for example, Patent Document 2).

  The prior art hermetic compressor will be described below with reference to the drawings. In the following description, the upper and lower relationships are based on a state in which the hermetic compressor is installed in a normal posture.

  FIG. 15 is a longitudinal sectional view of a conventional hermetic compressor described in Patent Document 1, and FIG. 16 is an enlarged view of the vicinity of a rotor mounting portion in the hermetic compressor.

  15 and 16, the lubricating oil 4 is stored at the bottom of the sealed container 2, and the compressor body 6 is elastically supported by the suspension container 8 with respect to the sealed container 2.

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

  The shaft 18 of the compression element 12 includes a main shaft portion 20 and an eccentric shaft portion 22 that extends above the main shaft portion 20, and the main shaft portion 20 is inserted into a main bearing 26 of the cylinder block 24.

  On the outer diameter surface of the main shaft portion 20, there are an upper sliding portion 50, a lower sliding portion 52, an upper sliding portion 50 and a lower sliding portion having a diameter slightly smaller by about 10 to 20 μm than the inner diameter of the main bearing 26. A hollow portion 54 formed between the upper slide portion 50 and the diameter of the upper slide portion 50 is smaller than the lower slide portion 52 by about 200 μm. And it becomes the structure of the cantilever slide bearing which supports the compressive load etc. which act on the eccentric shaft part 22 with the oil film pressure which generate | occur | produces between the main bearing 26, the upper sliding part 50, and the lower sliding part 52. ing.

  The main shaft portion 20 has a cylindrical hole 58 concentric with the outer diameter surface of the main shaft portion 20 in order to supply oil to the sliding portions of each portion, and the upper end 80 of the hole portion 58 has a lower sliding portion. 52 in the middle of the length. The upper end 80 of the hole 58 has a communication hole 60 that communicates with the surface of the lower sliding part 52 on the outer side in the radial direction, and is formed in a disk shape. The throttle part 64 is mounted at the opening end of the hole part 58, and the stirrer 66 is a plate that is press-fitted and fixed in the hole part 58 adjacent to the upper part of the throttle part 64.

  The lower part of the main bearing 26 is housed in a cylindrical recess 16a provided in the rotor 16, and the lower end of the main bearing 26 and the bottom 16b of the recess 16a of the rotor 16 are opposed to each other with a gap of about 0.3 mm. doing.

  FIG. 19 is a longitudinal sectional view of a conventional hermetic compressor described in Patent Document 2, and FIG. 20 is a cross-sectional view of a main part of the conventional hermetic compressor described in Patent Document 2.

  19 and 20, the outer surface of the main shaft portion 20 of the shaft 18 includes a cylindrical portion 86 having a constant outer diameter, and an inclined surface 70 having a smaller outer diameter than the cylindrical portion 86. In the range of the rotation angle of the shaft 18 in which the load acting on the piston 30 is maximum, it is arranged in the concentrated load portion on the compression mechanism portion side.

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

  When the electric element 10 is energized, the rotor 16 rotates, and the shaft 18 rotates accordingly, and the compression element 12 performs a predetermined compression operation.

JP 2009-270551 A Japanese Patent Laid-Open No. 7-4355

  However, in the conventional configuration described in Patent Document 1, when the rotor 16 is fitted to the main shaft portion 20, the main shaft portion 20 is deformed and adversely affects the lubrication state between the main shaft portion 20 and the main bearing 26. give.

  Hereinafter, the state of the conventional sliding portion will be described with reference to FIGS. 17 and 18.

  FIG. 17 schematically shows the deformation caused by fitting the rotor 16 to the main shaft portion 20 and the state of inclination of the shaft 18 when a load is received.

  In FIG. 17, the rotor 16 is fitted into the thin main shaft portion 20 having a hole 58 therein by a method such as shrink fitting, whereby the main shaft portion 20 that is in contact with the rotor 16. The outer diameter is deformed to be reduced. The deformation of the outer diameter portion of the main shaft portion 20 occurs in the range of the thin portion around the hole portion 58, and the deformation portion is formed in the lower sliding portion 52 on the outer diameter side of the upper end 80 (FIG. 16) of the hole portion 58. Is located at the end 20a. Then, the further away from the rotor 16, the larger the diameter and the original outer diameter at the terminal end 20a.

  The distance between the end 20a of the deformed portion and the fitting portion of the rotor 16 is approximately half of the sliding width of the lower sliding portion 52, and the diameter change occurs in this narrow range. Will do.

  In the cantilever bearing, when a load is applied, the main shaft portion 20 is inclined within the clearance, but the inclination of the deformed portion due to the fitting of the rotor 16 is larger than the inclination of the main shaft. As a result, as shown in FIG. 17, in the lower sliding portion 52, the oil film closest to the main bearing 26 becomes the thin part at the end 20a of the deformation, and the gap becomes larger below the end 20a.

  FIG. 18 schematically shows an oil film generation state of the lower sliding portion 52.

As shown in FIG. 18, the oil film pressure 72 is maximized because the gap is small at the end 20a of the deformed portion. On the other hand, on the upper side and the lower side of the terminal end 20a, the oil film pressure at which a large gap is generated is small. As a result, since the oil film pressure generated as a whole is small, the oil film thickness in the vicinity of the terminal end 20a of the deformed portion becomes thin, local metal contact is likely to occur at the terminal end 20a, and efficiency decreases due to an increase in sliding loss. There is a problem that reliability decreases due to occurrence of wear and the like.

  Moreover, even when the inclined surface 70 is formed in the concentrated load portion on the compression mechanism portion side as in the configuration described in Patent Document 2, the lower sliding portion 52 of the main shaft portion 20 when the rotor 16 is fitted. Since the problem of deformation cannot be solved, the problem that local metal contact easily occurs in the lower sliding portion 52 remains unchanged.

  The present invention solves the above-mentioned conventional problems, prevents the occurrence of local metal contact of the lower sliding portion of the main shaft portion due to the fitting of the rotor, reduces the sliding loss, and improves the efficiency. The purpose is to improve the reliability, prevent the occurrence of wear, and improve the reliability.

In order to solve the above-mentioned conventional problems, the hermetic compressor of the present invention has a deformation mitigating means for mitigating deformation of the lower sliding portion of the main shaft portion due to the engagement of the rotor , and the deformation mitigation. The means is configured by arranging the upper end of the hole provided in the main shaft portion up to the position of the hollow portion .

  Thereby, it has the effect | action of preventing generation | occurrence | production of the local metal contact of the main bearing resulting from a deformation | transformation of the main-shaft part by a rotor being fitted, and a main-shaft part.

  The hermetic compressor of the present invention can prevent local metal contact at the sliding portion and reduce friction, thereby reducing input and improving efficiency. It is possible to improve the reliability by suppressing the occurrence of scratches and wear at the spindle sliding portion due to the contact.

1 is a longitudinal sectional view of a hermetic compressor according to Embodiment 1 of the present invention. Sectional drawing of the principal part in Embodiment 1 Schematic diagram showing the deformation state in the first embodiment The schematic diagram which shows the oil film pressure of the sliding part of the Embodiment 1 Vertical sectional view of a hermetic compressor according to Embodiment 2 of the present invention Sectional drawing of the principal part in Embodiment 2 Schematic diagram showing a deformed state in the second embodiment The schematic diagram which shows the oil film pressure of the sliding part of the same Embodiment 2 Vertical sectional view of a hermetic compressor according to Embodiment 3 of the present invention Sectional drawing of the principal part in Embodiment 3 Schematic diagram showing the deformation state in the third embodiment Vertical sectional view of a hermetic compressor according to Embodiment 4 of the present invention Sectional drawing of the principal part in Embodiment 4 Schematic diagram showing a deformed state in the fourth embodiment A longitudinal sectional view of a hermetic compressor showing a conventional example Cross section of the main part of the hermetic compressor Schematic diagram showing the deformation state of the sliding part of the hermetic compressor Schematic showing the oil film pressure at the sliding part of the same hermetic compressor Vertical sectional view of a hermetic compressor showing a different conventional example Cross section of the main part of the hermetic compressor

According to a first aspect of the present invention, an electric element including a stator and a rotor and a compression element disposed above the electric element are accommodated in a sealed container storing lubricating oil, and the compression element is disposed inside. A shaft having a cylindrical hole portion concentric with the outer diameter surface, the main shaft portion having the outer diameter surface fitted with the rotor and an eccentric shaft portion, a cylinder block having a cylinder, and the interior of the cylinder A piston inserted in a reciprocating manner, a connecting means for connecting the piston and the eccentric shaft portion, and a main bearing formed on the cylinder block for supporting the main shaft portion of the shaft. On the outer diameter surface of the main shaft portion, the upper sliding portion and the lower sliding portion are interposed between the upper sliding portion, the lower sliding portion, and the upper sliding portion and the lower sliding portion. A hollow portion having a smaller diameter than the portion, and the lower sliding by having the hole portion Is a thin-walled cylinder, and when the load accompanying the compression operation is applied to the shaft, the main shaft portion is inclined inside the main bearing, and the rotor is fitted therein. A deformation mitigating means for mitigating deformation of the lower sliding portion of the main shaft portion associated with the main shaft portion is provided , and the upper end of the hole portion provided in the main shaft portion is disposed up to the position of the hollow portion It is composed by doing .

By adopting such a configuration, the occurrence of local metal contact at the sliding portion due to deformation caused by the fitting of the rotor is prevented, and the friction at the sliding portion is reduced, thereby reducing input and efficiency. In addition, the occurrence of wear at the sliding portion can be suppressed and the reliability can be improved.
Further, by adopting such a configuration, the range of deformation of the lower sliding portion of the main shaft portion due to the fitting of the rotor can include the entire lower sliding portion, and the inclination due to the deformation of the lower sliding portion can be made gentle. Thus, local metal contact at the sliding portion can be prevented. As a result, by reducing the friction of the sliding portion, it is possible to further reduce the input and improve the efficiency in addition to the effects of the first or second invention. Moreover, the occurrence of wear at the sliding portion can be suppressed and the reliability can be improved, and the sliding surface due to deformation can be obtained without extremely reducing the width of the fitting portion to the main shaft portion of the rotor. The inclination of the rotor can be made gentle, the fixing to the main shaft portion by the fitting of the rotor can be ensured to prevent the rotor from falling off, and the reliability can be improved.

  According to a second invention, in the first invention, the deformation mitigating means is an inner diameter enlarged portion provided at an upper portion of a fitting surface with the main shaft portion of the rotor.

  As a result, by separating the fitting portion with the rotor from the lower sliding portion of the main shaft portion, the slope of the sliding surface of the lower sliding portion due to deformation is moderated, and the local in the sliding portion is reduced. Can be prevented from occurring. As a result, by reducing the friction of the sliding portion, it is possible to reduce the input, improve the efficiency, suppress the occurrence of wear at the sliding portion, and improve the reliability.

According to a third invention, in the first invention, the deformation mitigating means is a low-rigidity member having a lower rigidity than at least iron disposed between the rotor and the main shaft portion , the shaft being iron. It is.

  As a result, when the rotor is fitted, the low-rigidity member is deformed, while the deformation of the main shaft portion becomes minor, the inclination of the sliding surface of the lower sliding portion due to the deformation becomes gentle, and the local in the sliding portion is reduced. Generation of typical metal contact can be prevented. As a result, the friction of the sliding portion can be reduced, the input can be reduced to improve the efficiency, and the occurrence of wear at the sliding portion can be suppressed, and the reliability can be improved.

According to a fourth invention, in the first invention, the deformation mitigating means includes a circumferential groove provided on an outer surface of the main shaft portion between a position where the rotor is fitted to the main shaft portion and a lower sliding portion. It is a configuration.

By adopting such a configuration, when the rotor is fitted to the main shaft portion, the deformation of the main shaft portion on the upper side of the circumferential groove is reduced, so that the inclination due to the deformation of the lower sliding portion is moderated, Occurrence of local metal contact at the sliding portion can be prevented. As a result, the friction of the sliding portion can be reduced, the input can be reduced to improve the efficiency, and the occurrence of wear at the sliding portion can be suppressed, and the reliability can be improved.
In a fifth aspect based on the first aspect, the lower sliding portion has an inclined surface whose outer diameter gradually decreases in a direction approaching the rotor .
A sixth invention is a refrigeration apparatus including the hermetic compressor according to any one of the first to fifth inventions.

  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 the first embodiment of the present invention, and FIG. 2 is a cross-sectional view of a main part of the hermetic compressor according to the first embodiment.

  1 and 2, the lubricating oil 104 is stored at the bottom inside the sealed container 102, and the compressor body 106 is suspended inside by a suspension spring 108. The sealed container 102 is filled with R600a (isobutane), which is a refrigerant with a low global warming potential.

  The compressor body 106 includes an electric element 110 and a compression element 112 driven by the electric element 110, and a power supply terminal 113 for supplying power to the electric element 110 is attached to the sealed container 102.

  First, the electric element 110 will be described.

  The electric element 110 includes an iron core in which steel plates are laminated, a stator 114 having windings, and a rotor 116 disposed on the inner diameter side of the stator 114, and the windings of the stator 114 provide power terminals 113. Via, it is connected to a power source (not shown) outside the hermetic compressor by a conducting wire.

  Next, the compression element 112 will be described.

  The compression element 112 is disposed above the electric element 110. The shaft 118 constituting the compression element 112 includes a main shaft portion 120 and an eccentric shaft portion 122 extending from the upper end of the main shaft portion 120 and parallel to the main shaft portion 120. Further, the main shaft portion 120 has a hole portion 158 concentric with the outer diameter inside, and the rotor 116 is fixed to the outer diameter surface by a method such as shrink fitting.

  The cylinder block 124 includes a main bearing 126 having a cylindrical inner surface, and the shaft 118 is supported by the main shaft portion 120 being inserted into the main bearing 126 in a rotatable state. The compression element 112 has a configuration of a cantilever bearing that supports the load acting on the eccentric shaft portion 122 by the main shaft portion 120 and the main bearing 126 arranged below the eccentric shaft portion 122.

  The cylinder block 124 includes a cylinder 134 that is a cylindrical hole, and a piston 130 is reciprocally inserted into the cylinder 134.

  Further, the connecting means 136 connects the eccentric shaft portion 122 and the piston 130 by the holes provided at both ends being respectively inserted into the piston pin 138 attached to the piston 130 and the eccentric shaft portion 122. .

  A valve plate 140 is attached to the end face of the cylinder 134 and forms a compression chamber 142 together with the cylinder 134 and the piston 130. Further, a cylinder head 144 is fixed so as to cover the valve plate 140 and cover it. The suction muffler 146 is molded from a resin such as PBT, forms a silencing space inside, and is attached to the cylinder head 144.

  Next, details of the main shaft 120 will be described.

  On the outer diameter surface of the main shaft portion 120, there are an upper sliding portion 150 and a lower sliding portion 152 having a diameter smaller by about 10 to 20 μm than the inner diameter of the main bearing 126, and the upper sliding portion 150 and the lower sliding portion 152. In the meantime, a hollow portion 154 having a diameter smaller than the upper sliding portion 150 and the lower sliding portion 152 by about 200 μm or more is disposed.

  In addition, a cylindrical hole 158 concentric with the outer diameter surface is provided inside the main shaft 120. The upper end 180 of the hole 158 is provided with a communication hole 160 that communicates with the spiral oil supply groove 174 in the lower sliding portion 152 on the surface of the main shaft 120. A portion from the middle to the lower side of the lower sliding portion 152 in which the inside of the main shaft portion 120 is a hole portion 158 has a thin cylindrical shape.

  Further, the lower end of the main shaft portion 120 of the shaft 118 is immersed in the lubricating oil 104 stored in the bottom of the sealed container 102, and is formed in a disk shape inside the hole portion 158, with a hole portion at the center thereof. A throttle part (not shown) having a hole with a smaller diameter than 158 and attached to the lower opening end of the hole part 158, and a plate press-fitted and fixed in the hole part 158 adjacent to the upper part of the throttle part A stirrer (not shown) which is a body is arranged.

  The lower portion of the main bearing 126 is housed in a cylindrical recess 116a provided in the rotor 116, and the lower end of the main bearing 126 and the bottom 116b of the recess 116a of the rotor 116 have a gap of about 0.1 to 1 mm. Is facing through. The gap between the lower end of the main bearing 126 and the bottom 116b of the recess 116a of the rotor 116 is set so as to regulate the position of the shaft 118 and prevent the occurrence of unwanted contact between parts at other parts. .

  Furthermore, the rotor 116 includes an inner diameter enlarged portion 178 as a deformation relaxation means 176 between the bottom 116b of the recess 116a and the fitting surface 116c with the main shaft portion 120. The inner diameter enlarged portion 178 has an inner diameter that is about 0.2 to 1 mm larger than the fitting surface 116 c and has a vertical width in the range of about 1 to 5 mm.

  More specifically, the fitting portion of the rotor 116 with the main shaft portion 120 is an iron core portion formed by laminating electromagnetic steel plates having a plate thickness of 0.3 to 0.5 mm, and the inner diameter enlarged portion 178 is a fitting portion. Manufactured by a method of stacking several magnetic steel sheets whose inner diameters have been punched in advance from the mating surface 116c.

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

  When the electric element 110 is energized from the power supply terminal 113, the rotor 116 rotates together with the shaft 118 by the magnetic field generated in the stator 114. The eccentric rotation of the eccentric shaft portion 122 accompanying the rotation of the main shaft portion 120 is converted by the connecting means 136 and causes the piston 130 to reciprocate within the cylinder 134. Then, when the volume of the compression chamber 142 changes, a compression operation is performed in which the refrigerant in the sealed container 102 is sucked into the compression chamber 142 and compressed.

  In the suction stroke accompanying the compression operation, the refrigerant in the sealed container 102 is intermittently sucked into the compression chamber 142 via the suction muffler 146 and compressed in the compression chamber 142, and then the high-temperature and high-pressure refrigerant is discharged. It is sent from the sealed container 102 to the refrigeration cycle (not shown) via the pipe 148 and the like.

Further, as the shaft 118 rotates, the lubricating oil 104 introduced into the hole 158 from the hole provided in the center of the throttle portion is rotated at the same speed as the shaft 118 by the stirrer, and centrifugal force acts. Then, it moves upward of the outer peripheral surface in the hole 158. And it is conveyed further upward, lubricating the sliding part of the main bearing 126 and the main-shaft part 120 by being supplied to the oil supply groove | channel 174 of the main-shaft part 120 from the communicating hole 160. FIG.

  Further, the load accompanying the compression operation acts on the eccentric shaft portion 122 of the shaft 118 from the connecting means 136, and the shaft 118 is supported by the main shaft portion 120 and the main bearing 126 arranged below the eccentric shaft portion 122, At this time, the main shaft portion 120 is inclined within the clearance of the main bearing 126.

  FIG. 3 schematically shows the inclination when a load is applied to the shaft 118 and the deformation when the rotor 116 is fitted to the main shaft portion 120 by shrink fitting.

  The outer diameter of the main shaft portion 120 in contact with the rotor 116 is reduced by fitting the rotor 116 to the thin main shaft portion 120 by a shrink fitting method or the like. doing. The deformation of the outer diameter portion continues in a range where the main shaft portion 120 has a thin shape from the contact portion of the main shaft portion 120 and the rotor 116, and approaches the original outer diameter as the distance from the rotor 116 increases. . Further, the upper end of this deformation range is a terminal end 120 a located on the outer diameter side of the upper end 180 of the hole 158, and is located in the middle of the lower sliding portion 152.

  The lower end of this deformation range is not the bottom 116b of the recess 116a, but the lower end of the inner diameter enlarged portion 178 provided below the bottom portion 116b. The diameter gradually changes with a longer width compared to the case without the inner diameter enlarged portion 178. As a result, a gentle inclined surface is formed.

  The state of the oil film pressure when the main shaft portion 120 thus deformed is inclined inside the main bearing 126 will be described with reference to FIG.

  FIG. 4 schematically shows the oil film distribution in the lower sliding portion 152 when the main shaft portion 120 is inclined in the main bearing 126.

  In FIG. 4, the lower sliding portion 152 is formed with an inclined surface whose outer diameter is gradually reduced on the lower side of the end 120a of the deforming portion. Since the inclination of the inclined surface is close to the inclination of the main shaft portion 120 in the clearance, the deformed portion forms a surface substantially parallel to the inner diameter surface of the main bearing 126, and the oil film pressure 172 is generated with a wide width. As a result, the oil film thickness at this site can be increased, and local metal contact can be prevented from occurring. Accordingly, it is possible to prevent a decrease in efficiency due to an increase in sliding loss, and it is also possible to prevent the occurrence of metal contact, thereby preventing a decrease in reliability due to the occurrence of wear or the like.

  In addition, in this Embodiment 1, although it formed by changing the shape of the iron plate which laminates | stacks the internal diameter expansion part 178, you may process and provide after lamination | stacking. In addition, although the cross-sectional shape of the inner diameter enlarged portion 178 is rectangular, the inner diameter enlarged portion 178 may be formed as a triangle or a curved surface as long as it does not prevent the inclined portion from being gently inclined.

  In the first embodiment, the hole portion 158 is concentric with the outer diameter of the main shaft portion 120. However, even when the hole portion 158 is not concentric, the same effect can be obtained for the deformation of the thin portion.

(Embodiment 2)
FIG. 5 is a longitudinal sectional view of the hermetic compressor according to the second embodiment of the present invention, and FIG. 6 is a main part sectional view of the hermetic compressor according to the second embodiment.

  5 and 6, lubricating oil 204 is stored in the bottom of the sealed container 202, and the compressor body 206 is suspended inside by a suspension spring 208. The sealed container 202 is filled with R600a (isobutane), which is a refrigerant with a low global warming potential.

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

  First, the electric element 210 will be described.

  The electric element 210 includes an iron core in which steel plates are laminated, a stator 214 having a winding, and a rotor 216 disposed on the inner diameter side of the stator 214, and the winding of the stator 214 is connected to a power supply terminal 213. And is connected to a power source (not shown) outside the hermetic compressor by a conductive wire.

  Next, the compression element 212 will be described.

  The compression element 212 is disposed above the electric element 210. The shaft 218 constituting the compression element 212 includes a main shaft portion 220 and an eccentric shaft portion 222 extending from the upper end of the main shaft portion 220 and parallel to the main shaft portion 220. Further, the main shaft portion 220 has a hole portion 258 concentric with the outer diameter inside, and the rotor 216 is fixed to the outer diameter surface by a method such as shrink fitting.

  The cylinder block 224 includes a main bearing 226 having a cylindrical inner surface, and the shaft 218 is supported by the main shaft portion 220 being inserted into the main bearing 226 in a rotatable state. The compression element 212 is configured as a cantilever bearing that supports the load acting on the eccentric shaft portion 222 with the main shaft portion 220 and the main bearing 226 disposed below the eccentric shaft portion 222.

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

  Further, the coupling means 236 couples the eccentric shaft portion 222 and the piston 230 by the holes provided at both ends being fitted and inserted into the piston pin 238 attached to the piston 230 and the eccentric shaft portion 222, respectively. .

  A valve plate 240 is attached to the end face of the cylinder 234 and forms a compression chamber 242 together with the cylinder 234 and the piston 230. Further, a cylinder head 244 is fixed so as to cover the valve plate 240 and cover it. The suction muffler 246 is molded from a resin such as PBT, forms a silencing space inside, and is attached to the cylinder head 244.

  Next, details of the main shaft portion 220 will be described.

  On the outer diameter surface of the main shaft portion 220, there are an upper sliding portion 250 and a lower sliding portion 252 having a diameter smaller than the inner diameter of the main bearing 226 by about 10 to 20 μm, and the upper sliding portion 250 and the lower sliding portion 252. In the meantime, a hollow portion 254 having a diameter smaller than the upper sliding portion 250 and the lower sliding portion 252 by about 200 μm or more is disposed.

  In addition, a cylindrical hole portion 258 concentric with the outer diameter surface is provided inside the main shaft portion 220. The upper end 280 of the hole 258 is located on the inner diameter side of the hollow portion 254.

  Further, a communication hole 260 that communicates from the inner diameter portion of the lower sliding portion 252 of the hole portion 258 to the spiral oil supply groove 274 on the outer surface of the main shaft portion 220 is provided. A portion from the middle to the lower side of the hollow portion 254 in which the inside of the main shaft portion 220 is a hole portion 258, that is, the entire lower sliding portion 252 forms a thin cylindrical shape.

  Further, the lower end of the main shaft portion 220 of the shaft 218 is immersed in the lubricating oil 204 stored in the bottom portion of the sealed container 202, and is formed in a disk shape inside the hole portion 258, and a hole portion is formed at the center portion thereof. A throttle part (not shown) having a hole smaller in diameter than 258 and mounted on the lower opening end of the hole part 258, and a plate body press-fitted and fixed in the hole part adjacent to the upper part of the throttle part A stirring bar (not shown) is arranged.

  The lower portion of the main bearing 226 is housed in a cylindrical recess 216a provided in the rotor 216, and the lower end of the main bearing 226 and the bottom 216b of the recess 216a of the rotor 216 have a gap of about 0.1 to 1 mm. Is facing through. Note that the gap between the lower end of the main bearing 226 and the bottom 216b of the recess 216a of the rotor 216 is set so as to regulate the position of the shaft 218 and prevent the occurrence of undesired contact between parts at other parts. .

  Furthermore, the rotor 216 includes an inner diameter enlarged portion 278 between the bottom portion 216b of the recess 216a and the fitting surface 216c with the main shaft portion 220. The inner diameter enlarged portion 278 has an inner diameter that is about 0.2 to 1 mm larger than the fitting surface 216c, and a vertical width of about 1 to 5 mm.

  More specifically, the fitting portion of the rotor 216 with the main shaft portion 220 is an iron core portion formed by laminating electromagnetic steel plates having a thickness of 0.3 to 0.5 mm, and the inner diameter enlarged portion 278 is fitted. Manufactured by a method of stacking several magnetic steel sheets whose inner diameters have been punched in advance from the mating surface 216c.

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

  When the electric element 210 is energized from the power supply terminal 213, the rotor 216 rotates with the shaft 218 by the magnetic field generated in the stator 214. The eccentric rotation of the eccentric shaft portion 222 accompanying the rotation of the main shaft portion 220 is converted by the connecting means 236 and causes the piston 230 to reciprocate within the cylinder 234. Then, when the compression chamber 242 changes in volume, a compression operation is performed in which the refrigerant in the sealed container 202 is sucked into the compression chamber 242 and compressed.

  In the suction stroke accompanying the compression operation, the refrigerant in the sealed container 202 is intermittently sucked into the compression chamber 242 via the suction muffler 246 and compressed in the compression chamber 242, and then the high-temperature and high-pressure refrigerant is discharged. It is sent from the sealed container 202 to the refrigeration cycle (not shown) via the pipe 248 and the like.

  Further, as the shaft 218 rotates, the lubricating oil 204 introduced into the hole 258 from the hole provided in the center of the throttle portion is rotated at the same speed as the shaft 218 by the stirrer, and centrifugal force acts. Then, it moves above the outer peripheral surface in the hole 258. And it is conveyed further upward, lubricating the sliding part of the main bearing 226 and the main shaft part 220 by being supplied to the oil supply groove 274 of the main shaft part 220 from the communication hole 260.

  Further, the load accompanying the compression operation acts on the eccentric shaft portion 222 of the shaft 218 from the connecting means 236, and the shaft 218 is supported by the main shaft portion 220 and the main bearing 226 disposed below the eccentric shaft portion 222. At this time, the main shaft portion 220 is inclined within the clearance of the main bearing 226.

  FIG. 7 schematically shows the inclination when a load is applied to the shaft 218 and the deformation when the rotor 216 is fitted to the main shaft portion 220 by shrink fitting.

The outer diameter of the main shaft portion 220 that is in contact with the rotor 216 is reduced by fitting the rotor 216 to the thin main shaft portion 220 by a shrink fitting method or the like. doing. The reduction of the outer diameter portion continues in a range where the main shaft portion 220 has a thin shape from the contact portion of the main shaft portion 220 and the rotor 216, and approaches the original outer diameter as the distance from the rotor 216 increases. . Further, the upper end of this deformation range is located in the hollow portion 254 on the outer diameter side of the upper end 280 of the hole 258, and the entire lower sliding portion 252 is included in this deformation range.

  The lower end of this deformation range is not the bottom 216b of the recess 216a, but the lower end of the inner diameter enlarged portion 278 provided below the bottom 216b. The diameter gradually changes with a longer width compared to the case without the inner diameter enlarged portion 278. As a result, a gentle inclined surface is formed.

  The state of the oil film pressure when such a main shaft portion 220 is inclined inside the main bearing 226 will be described with reference to FIG.

  FIG. 8 schematically shows the oil film distribution in the lower sliding portion 252 when the main shaft portion 220 is inclined in the main bearing 226.

  In FIG. 8, the lower sliding portion 252 is entirely included in the deformed portion, and forms an inclined surface whose outer diameter gradually decreases toward the bottom. Since the inclination of the inclined surface is close to the inclination of the main shaft portion 220 in the clearance, the oil film thickness of the entire lower sliding portion 252 becomes uniform, and an oil film pressure 272 is generated over the lower sliding portion 252. Therefore, there is no portion where the oil film thickness is locally small, and local metal contact can be prevented from occurring. Accordingly, it is possible to prevent a decrease in efficiency due to an increase in sliding loss, and it is also possible to prevent the occurrence of metal contact, thereby preventing a decrease in reliability due to the occurrence of wear or the like.

  Further, in the second embodiment, the deformation relaxing means 276 includes the inner diameter enlarged portion 278 to prevent the occurrence of local metal contact, and at the same time the position of the upper end 280 of the hole 258 is the position of the hollow portion 254. Therefore, the inclination of deformation due to the fitting of the rotor 216 can be further reduced, and local metal contact can be prevented from occurring.

  Moreover, even if the vertical width of the inner diameter enlarged portion 278 is reduced by disposing the position of the upper end 280 of the hole portion 258 to the position of the hollow portion 254 as the deformation mitigating means 276, the lower sliding portion 252 is provided. It can be a gentle inclined surface. As a result, a sufficient contact width between the rotor 216 and the main shaft portion 220 can be secured, and the rotor 216 can be reliably fitted and fixed, thereby improving reliability.

  In the second embodiment, the hole 258 is concentric with the outer diameter. However, even if the hole is not concentric, the same effect can be obtained for the deformation of the thin portion.

(Embodiment 3)
FIG. 9 is a longitudinal sectional view of the hermetic compressor according to the third embodiment of the present invention, and FIG. 10 is a main part sectional view of the hermetic compressor according to the third embodiment.

  9 and 10, lubricating oil 304 is stored in the bottom of the sealed container 302, and the compressor body 306 is suspended inside by a suspension spring 308. The sealed container 302 is filled with R600a (isobutane), which is a refrigerant with a low warming potential.

  The compressor body 306 includes an electric element 310 and a compression element 312 driven by the electric element 310, and a power supply terminal 313 for supplying power to the electric element 310 is attached to the sealed container 302.

  First, the electric element 310 will be described.

  The electric element 310 includes a stator 314 having an iron core laminated with steel plates and a winding, and a rotor 316 disposed on the inner diameter side of the stator 314, and the winding of the stator 314 is connected to a power supply terminal 313. And is connected to a power source (not shown) outside the hermetic compressor by a conductive wire.

  Next, the compression element 312 will be described.

  The compression element 312 is disposed above the electric element 310. The shaft 318 constituting the compression element 312 includes a main shaft portion 320 and an eccentric shaft portion 322 extending from the upper end of the main shaft portion 320 and parallel to the main shaft portion 320. Further, the main shaft portion 320 has a hole portion 358 concentric with the outer diameter inside, and the rotor 316 is fixed to the outer diameter surface via a low-rigidity member 382 as the deformation relaxation means 376. The low-rigidity member 382 is, for example, a substantially cylindrical type having a lower rigidity than iron, which is a material of the shaft 318 and the rotor 316, desirably made of an elastic material, and specifically made of a material such as aluminum. It is a shaped member.

  The cylinder block 324 includes a main bearing 326 having a cylindrical inner surface, and the shaft 318 is supported by the main shaft portion 320 being rotatably inserted into the main bearing 326. The compression element 312 has a configuration of a cantilever bearing that supports the load acting on the eccentric shaft portion 322 with the main shaft portion 320 and the main bearing 326 arranged below the eccentric shaft portion 322.

  The cylinder block 324 includes a cylinder 334 that is a cylindrical hole, and a piston 330 is reciprocally inserted into the cylinder 334.

  Further, the coupling means 336 couples the eccentric shaft portion 322 and the piston 330 by the holes provided at both ends being fitted and inserted into the piston pin 338 attached to the piston 330 and the eccentric shaft portion 322, respectively. .

  A valve plate 340 is attached to the end surface of the cylinder 334 and forms a compression chamber 342 together with the cylinder 334 and the piston 330. Further, a cylinder head 344 is fixed so as to cover the valve plate 340 and cover it. The suction muffler 346 is molded from a resin such as PBT, forms a silencing space inside, and is attached to the cylinder head 344.

  Next, details of the main shaft portion 320 will be described.

  On the outer diameter surface of the main shaft portion 320, there are an upper sliding portion 350 and a lower sliding portion 352 having a diameter smaller than the inner diameter of the main bearing 326 by about 10 to 20 μm, and an upper sliding portion 350 and a lower sliding portion 352. In the meantime, a hollow portion 354 having a diameter smaller than the upper sliding portion 350 and the lower sliding portion 352 by about 200 μm or more is disposed.

  In addition, a cylindrical hole 358 concentric with the outer diameter surface is provided inside the main shaft portion 320. The upper end 380 of the hole 358 is located on the inner diameter side of the lower sliding portion 352.

  Further, a communication hole 360 that communicates from the inner diameter portion of the lower sliding portion 352 of the hole portion 358 to the spiral oil supply groove 374 on the outer surface of the main shaft portion 320 is provided. The inside portion of the main shaft portion 320 is a hole portion 358, and the portion from the middle to the lower side of the lower sliding portion 352 forms a thin cylindrical shape.

Further, the lower end of the main shaft portion 320 of the shaft 318 is immersed in the lubricating oil 304 stored in the bottom portion of the hermetic container 302, and is formed in a disk shape inside the hole portion 358. 358 is a plate having a smaller diameter than 358, a throttle part 364 mounted on the lower opening end of the hole part 358, and a plate body press-fitted and fixed in the hole part 358 adjacent to the upper part of the throttle part 364. A stir bar 366 is disposed.

  Furthermore, the lower part of the main bearing 326 is housed in a cylindrical recess 316a provided in the rotor 316, and the lower end of the main bearing 326 and the bottom 316b of the recess 316a of the rotor 316 are about 0.1 to 1 mm apart. Is facing through.

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

  When the electric element 310 is energized from the power supply terminal 313, the rotor 316 rotates together with the shaft 318 by the magnetic field generated in the stator 314. The eccentric rotation of the eccentric shaft portion 322 accompanying the rotation of the main shaft portion 320 is converted by the connecting means 336 and causes the piston 330 to reciprocate within the cylinder 334. Then, when the volume of the compression chamber 342 changes, the refrigerant in the hermetic container 302 is sucked into the compression chamber 342 and compressed.

  In the suction stroke accompanying the compression operation, the refrigerant in the sealed container 302 is intermittently sucked into the compression chamber 342 via the suction muffler 346 and compressed in the compression chamber 342, and then the high-temperature and high-pressure refrigerant is discharged. It is sent to the refrigeration cycle (not shown) from the sealed container 302 via the pipe 348 and the like.

  In addition, as the shaft 318 rotates, the lubricating oil 304 introduced into the hole 358 from the hole provided in the center of the throttle portion is rotated at the same speed as the shaft 318 by the stirrer, and centrifugal force acts. Then, it moves upward of the outer peripheral surface in the hole 358. And it is conveyed further upward, lubricating the sliding part of the main bearing 326 and the main-shaft part 320 by being supplied from the communicating hole 360 to the oil supply groove 374 of the main-shaft part 320.

  Further, the load accompanying the compression operation acts on the eccentric shaft portion 322 of the shaft 318 from the connecting means 336, and the shaft 318 is supported by the main shaft portion 320 and the main bearing 326 arranged below the eccentric shaft portion 322. At this time, the main shaft portion 320 is inclined within the clearance of the main bearing 326.

  FIG. 11 schematically shows the inclination when a load is applied to the shaft 318 and the deformation when the rotor 316 is fitted to the main shaft portion 320 by shrink fitting.

  When the rotor 316 is attached to the thin main shaft portion 320 having the hole portion 358, the low rigidity member is fixed by the low rigidity member 382 by the tightening force by shrink fitting. Although 382 greatly deforms, the deformation of the main shaft portion 320 is slight.

  As a result, the slope of the sliding surface of the lower sliding portion 352 accompanying the deformation of the main shaft portion 320 due to the fitting of the rotor 316 is moderated to prevent the occurrence of local metal contact at the sliding portion, By reducing the friction of the sliding portion, it is possible to reduce the input and improve the efficiency, suppress the occurrence of wear at the sliding portion, and improve the reliability.

(Embodiment 4)
FIG. 12 is a longitudinal sectional view of the hermetic compressor according to the fourth embodiment of the present invention, and FIG. 13 is a main part sectional view of the hermetic compressor according to the fourth embodiment.

In FIGS. 12 and 13, lubricating oil 404 is stored at the bottom inside the sealed container 402, and the compressor body 406 is suspended inside by a suspension spring 408. The sealed container 402 is filled with R600a (isobutane), which is a refrigerant with a low global warming potential.

  The compressor body 406 includes an electric element 410 and a compression element 412 driven by the electric element 410, and a power supply terminal 413 for supplying power to the electric element 410 is attached to the sealed container 402.

  First, the electric element 410 will be described.

  The electric element 410 includes an iron core laminated with steel plates, a stator 414 having windings, and a rotor 416 arranged on the inner diameter side of the stator 414, and the windings of the stator 414 are connected to the power supply terminal 413. And is connected to a power source (not shown) outside the hermetic compressor by a conductive wire.

  Next, the compression element 412 will be described.

  The compression element 412 is disposed above the electric element 410. The shaft 418 constituting the compression element 412 includes a main shaft portion 420 and an eccentric shaft portion 422 extending from the upper end of the main shaft portion 420 and parallel to the main shaft portion 420. Further, the main shaft portion 420 has a hole portion 458 concentric with the outer diameter inside, and the rotor 416 is fitted to the outer diameter surface by a method such as shrink fitting.

  The cylinder block 424 includes a main bearing 426 having a cylindrical inner surface, and the shaft 418 is supported by the main shaft portion 420 being inserted into the main bearing 426 in a rotatable state. The compression element 412 has a configuration of a cantilever bearing that supports the load acting on the eccentric shaft portion 422 with the main shaft portion 420 and the main bearing 426 disposed below the eccentric shaft portion 422.

  The cylinder block 424 includes a cylinder 434 that is a cylindrical hole, and a piston 430 is reciprocally inserted into the cylinder 434.

  Further, the connecting means 436 connects the eccentric shaft portion 422 and the piston 430 by the hole portions provided at both ends being fitted and inserted into the piston pin 438 attached to the piston 430 and the eccentric shaft portion 422, respectively. .

  A valve plate 440 is attached to the end surface of the cylinder 434 and forms a compression chamber 442 together with the cylinder 434 and the piston 430. Further, a cylinder head 444 is fixed so as to cover the valve plate 440 and cover it. The suction muffler 446 is molded from a resin such as PBT, forms a silencing space inside, and is attached to the cylinder head 444.

  Next, details of the main shaft 420 will be described.

  On the outer diameter surface of the main shaft portion 420, there are an upper sliding portion 450 and a lower sliding portion 452 having a diameter that is about 10 to 20 μm smaller than the inner diameter of the main bearing 426, and the upper sliding portion 450 and the lower sliding portion 452. In the meantime, a hollow portion 454 having a diameter smaller than the upper sliding portion 450 and the lower sliding portion 452 by about 200 μm or more is disposed.

  In addition, a cylindrical hole 458 concentric with the outer diameter surface is provided inside the main shaft 420. The upper end 480 of the hole 458 is located on the inner diameter side of the lower sliding portion 452.

  Further, a communication hole 460 that communicates from the inner diameter portion of the lower sliding portion 452 of the hole portion 458 to the spiral oil supply groove 474 on the outer surface of the main shaft portion 420 is provided. The middle portion of the lower sliding portion 452 in which the inside of the main shaft portion 420 is a hole portion 458 has a thin cylindrical shape.

  Further, the lower end of the main shaft portion 420 of the shaft 418 is immersed in the lubricating oil 404 stored in the bottom portion of the sealed container 402, and is formed in a disk shape inside the hole portion 458, and a hole portion is formed in the center portion thereof. A throttle part 464 having a hole with a smaller diameter than 458 and mounted at the lower opening end of the hole part 458, and a plate body press-fitted and fixed in the hole part 458 adjacent to the upper part of the throttle part 464. A stir bar 466 is arranged.

  Further, the lower portion of the main bearing 426 is housed in a cylindrical recess 416a provided in the rotor 416, and the lower end of the main bearing 426 and the bottom 416b of the recess 416a of the rotor 416 are about 0.1 to 1 mm apart. Is facing through.

  Further, an annular circumferential groove 484 serving as a deformation relaxation means 476 is provided between the lower sliding portion 452 of the outer surface of the main shaft portion 420 and the fitting portion surface of the rotor 416.

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

  When the electric element 410 is energized from the power supply terminal 413, the rotor 416 rotates together with the shaft 418 by the magnetic field generated in the stator 414. The eccentric rotation of the eccentric shaft portion 422 accompanying the rotation of the main shaft portion 420 is converted by the connecting means 436 and causes the piston 430 to reciprocate within the cylinder 434. Then, when the compression chamber 442 changes in volume, the refrigerant in the sealed container 402 is sucked into the compression chamber 442 and compressed.

  In the suction stroke accompanying the compression operation, the refrigerant in the sealed container 402 is intermittently sucked into the compression chamber 442 through the suction muffler 446 and compressed in the compression chamber 442, and then the high-temperature and high-pressure refrigerant is discharged. It is sent to the refrigeration cycle (not shown) from the sealed container 402 via the pipe 448 and the like.

  Further, as the shaft 418 rotates, the lubricating oil 404 introduced into the hole 458 from the hole provided in the center of the throttle portion is rotated at the same speed as the shaft 418 by the stirrer, and centrifugal force acts. Then, it moves above the outer peripheral surface in the hole 458. Then, by being supplied from the communication hole 460 to the oil supply groove 474 of the main shaft portion 420, the sliding portion between the main bearing 426 and the main shaft portion 420 is lubricated and further conveyed upward.

  Further, the load accompanying the compression operation acts on the eccentric shaft portion 422 of the shaft 418 from the connecting means 436, and the shaft 418 is supported by the main shaft portion 420 and the main bearing 426 disposed below the eccentric shaft portion 422. At this time, the main shaft portion 420 is inclined within the clearance of the main bearing 426.

  FIG. 14 schematically shows the inclination when a load is applied to the shaft 418 and the deformation when the rotor 416 is fitted to the main shaft portion 420 by shrink fitting.

  When the rotor 416 is attached to the main shaft portion 420 having a hole portion 458 and having a thin shape, the main shaft portion 420 is deformed so that the diameter is reduced by a tightening force by shrink fitting. However, a circumferential groove 484 is provided above the mounting portion of the rotor 416, and the rigidity of the shaft 418 is low in the circumferential groove 484 portion. Therefore, by absorbing the distortion due to the fitting of the rotor 416, the lower sliding portion 452 above the circumferential groove 484 hardly deforms.

As a result, it is possible to prevent the problem that no oil film pressure is generated at the lower end of the main shaft portion 420 in the lower sliding portion 452 and to effectively use the length of the main bearing 426. The surface pressure can be lowered. Therefore, it is possible to prevent a decrease in efficiency due to an increase in sliding loss due to the occurrence of local metal contact, and it is possible to prevent a decrease in reliability due to the occurrence of wear or the like.

  As described above, the hermetic compressor according to the present invention can prevent deformation of the main shaft sliding portion when the rotor is attached and improve efficiency and reliability by the deformation mitigation means. However, the present invention can be widely applied to air conditioners, vending machines, other refrigeration apparatuses, and the like.

102, 202, 302, 402 Airtight container 104, 204, 304, 404 Lubricating oil 110, 210, 310, 410 Electric element 112, 212, 312, 412 Compression element 114, 214, 314, 414 Stator 116, 216, 316 416 Rotor 118, 218, 318, 418 Shaft 120, 220, 320, 420 Main shaft part 122, 222, 322, 422 Eccentric shaft part 124, 224, 324, 424 Cylinder block 126, 226, 326, 426 Main bearing 130 , 230, 330, 430 Piston 134, 234, 334, 434 Cylinder 136, 236, 336, 436 Connecting means 150, 250, 350, 450 Upper sliding part 152, 252, 352, 452 Lower sliding part 154, 254, 354, 454 hollow section 158, 258, 358, 458 Hole 176, 276, 376, 476 Deformation mitigating means 178, 278 Inner diameter enlarged portion 280 Upper end 382 Low rigidity member 484 Annular groove

Claims (6)

In an airtight container storing lubricating oil, an electric element including a stator and a rotor, and a compression element disposed above the electric element are accommodated,
The compression element has a cylindrical hole portion concentric with the outer diameter surface inside, a shaft having a main shaft portion and an eccentric shaft portion in which the rotor is fitted on the outer diameter surface, and a cylinder having a cylinder A block, a piston inserted in the cylinder so as to be capable of reciprocating, a connecting means for connecting the piston and the eccentric shaft portion, and a cylinder block, which supports the main shaft portion of the shaft. With a main bearing
On the outer diameter surface of the main shaft portion, the upper sliding portion, the lower sliding portion, and the upper sliding portion and the lower sliding portion between the upper sliding portion and the lower sliding portion. A hollow portion having a small diameter is disposed,
By having the hole portion, a part of the lower sliding portion is a thin cylindrical shape,
When the load accompanying the compression operation is applied to the shaft, the main shaft portion is inclined inside the main bearing,
A deformation relaxation means for relaxing the deformation of the lower sliding portion of the main shaft portion when the rotor is fitted ;
A hermetic compressor in which the deformation relaxation means is configured by disposing an upper end of a hole provided in the main shaft portion to a position of a hollow portion . The hermetic compressor according to claim 1, wherein the deformation relaxation means is an enlarged inner diameter portion provided on an upper portion of a fitting surface with a main shaft portion of a rotor. 2. The hermetic compressor according to claim 1, wherein the shaft is iron and the deformation mitigating means is a low-rigidity member having a rigidity lower than at least iron disposed between the rotor and the main shaft portion. 2. The hermetic compression according to claim 1, wherein the deformation relaxation means includes a circumferential groove provided on an outer surface of the main shaft portion between a position where the rotor is fitted to the main shaft portion and a lower sliding portion. Machine. The hermetic compressor according to claim 1, wherein the lower sliding portion has an inclined surface whose outer diameter gradually decreases in a direction approaching the rotor . A refrigeration apparatus comprising the hermetic compressor according to any one of claims 1 to 5 .