JP5873961B2 - Hermetic compressor - Google Patents

Description

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

  Conventionally, this type of hermetic compressor employs a thrust ball bearing between a shaft and a bearing for the purpose of improving efficiency to reduce sliding loss (for example, see Patent Document 1).

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

  16 is a front sectional view of a conventional hermetic compressor described in Patent Document 1, FIG. 17 is an enlarged cross-sectional view of a main part during operation of the conventional hermetic compressor, and FIG. 18 is a conventional hermetic type. The principal part cross-sectional enlarged view at the time of operation stop after a long-time driving | running of a compressor is shown.

  In FIG. 16 thru | or FIG. 18, in the airtight container 1, the electric element 2 and the compression element 4 rotationally driven by this electric element 2 are each accommodated, and the oil 6 is stored in the bottom part. The electric element 2 and the compression element 4 are assembled together and elastically supported in the sealed container 1 by a plurality of coil springs (not shown).

  The compression element 4 includes a shaft 16 having an eccentric shaft portion 14 formed via a main shaft portion 10 and a flange portion 12, a cylinder block 22 forming a compression chamber 20, and a shaft block provided in the cylinder block 22 to support the shaft 16. A bearing 26 that reciprocates in the compression chamber 20, a connecting rod 30 that connects the piston 28 and the eccentric shaft portion 14, a lower surface 31 of the flange portion 12, and an upper end surface 32 of the bearing 26. The thrust ball bearing 34 is provided to form a reciprocating compressor.

  One end of the shaft 16 is an oil supply mechanism 36 immersed in the oil 6 stored in the sealed container 1, and an oil supply groove 38 for supplying a part of the oil 6 pumped up to the main shaft portion 10 by the oil supply mechanism 36 to the upper end surface 32. have.

  The electric element 2 includes a stator 40 fixed below the cylinder block 22 and a rotor 42 fixed to the main shaft portion 10 by shrink fitting or the like.

  The thrust ball bearing 34 includes a plurality of balls 52 made of bearing steel such as SUJ2, a resin cage 54 that holds the balls 52, and an upper race 56 and a lower race 58 that are respectively disposed above and below the balls 52. have. The ball 52 is held in a ball storage unit 60 provided in the cage 54, and a small amount is provided between the ball 52 and the ball storage unit 60 so that the ball 52 can freely roll in the ball storage unit 60. A gap (not shown) is provided.

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

  When the electric element 2 is energized from an external power source (not shown), the rotor 42 rotates, and the shaft 16 rotates accordingly, and the movement of the eccentric shaft portion 14 is transferred to the piston 28 via the connecting rod 30. It is transmitted. Thereby, the piston 28 reciprocates in the compression chamber 20, and the compression element 4 performs a predetermined compression operation. At this time, the oil supply mechanism 36 of the shaft 16 pumps up the oil 6 and lubricates each sliding portion (not shown). A part of the oil supply mechanism 36 is supplied from the oil supply groove 38 to the upper end surface 32, and the thrust ball bearing 34 is installed. Lubricate.

  The thrust ball bearing 34 supports a vertically downward load due to the weight of the rotor 42 and the shaft 16 by a point contact with the ball 52, and generates a frictional force generated between the lower surface 31 of the flange portion 12 and the upper end surface 32 of the bearing 26. To reduce. This reduces the input of the hermetic compressor and improves efficiency.

JP 2005-127305 A

  However, in the above conventional configuration, since the ball 52 rotates while sliding in the ball storage portion 60 of the cage 54, the sliding time between the ball 52 and the ball storage portion 60 increases as the operation time becomes longer. The ball storage portion 60 is worn excessively, and the diameter of the ball storage portion 60 gradually increases.

  Even when the diameter of the ball storage section 60 is widened, during operation, both the cage 54 and the ball 52 rotate around the shaft 16, so that a large centrifugal force is generated in the ball 52 having a larger specific gravity than the cage 54, The ball 52 rotates while pressing the outer peripheral wall surface of the ball storage unit 60 outward by centrifugal force. Therefore, the cage 54 floats on the upper surface of the lower race 58 and rotates.

  However, since the diameter of the ball storage portion 60 increases as the operation time becomes longer, the cage 54 cannot be held on a part of the surface of the ball 52 when the operation is stopped, as shown in FIG. It slips down to the upper surface of the lower race 58, and the lower surface of the retainer 54 and the entire upper surface of the lower race 58 come into contact uniformly.

  When oil remains on the upper surface of the lower race 58, the retainer 54 and the lower race 58 are in an adsorbing state due to the surface tension of the oil 6. When the hermetic compressor is started in this state, the cage 54 generates a centrifugal force on the ball 52, and the ball 52 pushes the outer peripheral wall of the ball storage portion 60 outward by the centrifugal force, and in this state, the cage It rotates while sliding with the lower race 58 until 54 floats on the upper surface 66 of the lower race 58. As a result, the friction resistance between the cage 54 and the lower race 58 is increased in the initial stage of startup, and the input is increased.

  Further, the conventional configuration has a problem that the retainer 54 and the lower race 58 slide each time the actuator is started, so that the lower surface of the retainer 54 is worn and the strength of the retainer 54 is deteriorated.

  The present invention solves the above-described conventional problem. The diameter of the ball storage portion 60 is widened, and when the operation is stopped, the retainer 54 is caught on a part of the surface of the ball 52 and cannot be held, so that the upper surface of the lower race 58 is removed. Even if it slips down, it prevents full contact between the lower surface of the cage 54 and the upper surface of the lower race 58, prevents an increase in frictional resistance between the cage 54 and the lower race 58, and prevents wear on the lower surface of the cage 54. An object of the present invention is to provide a highly efficient and highly reliable hermetic compressor that suppresses generation and suppresses an increase in input.

In order to solve the above problems, the hermetic compressor of the present invention, the cage, the lower surface and the upper surface of the lower race of the retainer to form a contact avoidance mechanism to prevent the entire surface contact, the contact avoidance mechanism Is formed by a convex part that protrudes from the lower surface of the cage, and the convex part is provided at a position that overlaps the track on the rolling surface of the lower race where the ball rolls. Even if the portion wears out and the diameter of the ball storage portion increases, the contact avoidance mechanism provided in the cage can prevent full contact between the cage and the race when the operation is stopped and started. As a result, an increase in frictional resistance between the cage and the lower race can be suppressed, and the strength of the cage can be prevented from being deteriorated due to wear on the lower surface of the cage.
In addition, with this configuration, the convex portion slides around the track (surface) on the rolling surface of the lower race where the ball rolls, and remains on the track (surface) when stopped. It works to remove worn dust and fine dust.

The hermetic compressor of the present invention can prevent the entire contact between the lower surface of the cage and the upper surface of the race at the time of activation by the contact avoidance mechanism provided in the cage. Therefore, an increase in frictional resistance due to the cage and the lower race can be prevented, and an increase in input can be suppressed.
In addition, the reliability of the ball and the lower race can be improved.

Front sectional view of the hermetic compressor according to the first embodiment of the present invention. Cross-sectional enlarged view during operation of the thrust bearing that constitutes the hermetic compressor Plan view of the cage of the thrust bearing part constituting the hermetic compressor Cross-sectional enlarged view at the time of operation stop after long-time operation of the thrust bearing part constituting the hermetic compressor Sectional enlarged view at the time of operation | movement of the thrust bearing part which comprises the hermetic compressor in Embodiment 2 of this invention Plan view of the cage of the thrust bearing part constituting the hermetic compressor Cross-sectional enlarged view at the time of operation stop after long-time operation of the thrust bearing part constituting the hermetic compressor Sectional enlarged view at the time of operation | movement of the thrust bearing part which comprises the hermetic compressor in Embodiment 3 of this invention Plan view of the cage of the thrust bearing part constituting the hermetic compressor Cross-sectional enlarged view at the time of operation stop after long-time operation of the thrust bearing part constituting the hermetic compressor Sectional enlarged view at the time of operation | movement of the thrust bearing part which comprises the hermetic compressor in Embodiment 4 of this invention Plan view of the cage of the thrust bearing part constituting the hermetic compressor Cross-sectional enlarged view at the time of operation stop after long-time operation of the thrust bearing part constituting the hermetic compressor The cross-sectional enlarged view at the time of the driving | operation of the thrust bearing part which comprises the sealed compressor in Embodiment 5 of this invention. Cross-sectional enlarged view at the time of operation stop after long-time operation of the thrust bearing part constituting the hermetic compressor Front sectional view of a conventional hermetic compressor Cross-sectional enlarged view of the main part during operation of a conventional hermetic compressor Cross-sectional enlarged view of the main part of a conventional hermetic compressor when the operation is stopped after a long operation

  According to a first aspect of the present invention, an oil, an electric element including a stator and a rotor, and a compression element driven by the electric element are accommodated in an airtight container, and the compression element includes a main shaft portion and the main shaft. Cylinder that forms a compression chamber, a flange that is formed at the tip of the shaft, a shaft that is formed through the flange and extends in the axial direction parallel to the axis of the main shaft, and a compression chamber A block, a bearing that is provided in the cylinder block and supports the shaft, a piston that reciprocates in the compression chamber, a connecting rod that connects the piston and the eccentric shaft portion, a flange portion, and the bearing A thrust bearing disposed between the upper end surface and the thrust bearing; a plurality of balls; a cage made of resin that holds the balls in a freely rolling manner; and the balls of It is configured to include an upper race and a lower race respectively disposed below, and the retainer is provided with a contact avoidance mechanism that prevents full contact between the lower surface of the retainer and the upper surface of the lower race. is there.

By adopting such a configuration, even when the ball storage portion wears out and the diameter of the ball storage portion expands with long-term use, the contact avoidance mechanism provided in the retainer can be used to stop and start the operation. It is possible to prevent full contact between the cage and the lower race. As a result, it is possible to suppress an increase in frictional resistance due to contact between the cage and the lower race, and to suppress deterioration in strength of the cage due to wear, and an increase in input due to wear on the lower surface of the cage. And the reliability of the compressor can be improved.

  According to a second invention, in the first invention, the contact avoidance mechanism is configured by a convex portion protruding from a lower surface of the cage, and the convex portion is provided on an outer peripheral side of the cage.

  With this configuration, when oil is supplied between the cage and the lower race from the inside of the cage by the oil supply mechanism of the shaft, and when the oil scatters to the outer peripheral side of the cage and the lower race by centrifugal force Oil can collide with the convex portion. Since the oil colliding with the convex portion drops and is used for lubrication of the ball rolling on the upper surface of the lower race, the lubricity of the thrust bearing can be improved.

According to a third invention, in the first invention, the contact avoidance mechanism is constituted by a convex portion protruding from a lower surface of the cage, and the convex portion is provided on an inner peripheral side of the cage. .

  With this configuration, the outer peripheral side of the thrust bearing is in a state where exposure from the ball cage is ensured. Therefore, the oil which is supplied to the piston and the connecting rod by the oil supply mechanism of the shaft and rebounds easily flows from the outer peripheral side of the thrust bearing to the ball side. Accordingly, oil can be easily supplied from the outer peripheral side of the cage to the cage and the lower race, the lubrication of the ball rolling on the upper surface of the lower race can be improved, and the reliability of the ball and the lower race can be improved. .

According to a fourth invention, in the first invention, the contact avoidance mechanism is configured by a holder projecting from an outer peripheral side wall of the cage and a projecting portion projecting from a lower surface of the holder.

  By adopting such a configuration, the strength of the cage can be increased, and the durability of the cage for a long period can be ensured. In addition, even when the cage is exposed to a high temperature, the holder serves as a cooling fin, can suppress the temperature rise of the cage and suppress the thermal strain of the cage, and can improve the durability of the thrust bearing. Reliability can be improved.

According to a fifth invention, in the first invention, the contact avoidance mechanism is formed by an inclined surface on the lower surface of the cage that increases in thickness in the axial direction of the cage from the inner circumferential side toward the outer circumferential side. It is a thing.

By adopting such a configuration, with long-term use, even if the ball storage portion wears and the diameter of each ball storage portion widens, even when the cage slips down to the upper surface of the lower race when operation is stopped, Since only the outer peripheral side of the cage is in line contact with the lower race, it is possible to prevent full contact between the cage and the lower race at the time of activation. Accordingly, it is possible to suppress an increase in frictional resistance between the cage and the lower race at the time of starting, and to prevent the strength of the cage from being deteriorated due to wear of the lower surface of the cage due to friction. The input can be suppressed and the reliability can be improved.

  Furthermore, since the axial thickness is changed so that the lower surface of the cage becomes an inclined surface, the surface of the ball exposed from the cage is exposed more toward the inside. As a result, the oil supply mechanism of the shaft makes it easy for oil supplied from the inside of the cage to adhere to the ball, making the ball lubricated in a good state and further improving the reliability.

  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 front sectional view of a hermetic compressor according to the first embodiment of the present invention, and FIG. 2 is an enlarged cross-sectional view of the thrust bearing portion constituting the hermetic compressor according to the first embodiment during operation. 3 is a plan view of a retainer of a thrust bearing portion constituting the hermetic compressor, and FIG. 4 is an enlarged cross-sectional view of the thrust bearing portion constituting the hermetic compressor when the operation is stopped after a long time operation. is there.

  1 to 4, an electric element 102 and a compression element 104 that is rotationally driven by the electric element 102 are accommodated and disposed in the sealed container 101, and oil 106 is stored in the inner bottom portion. The electric element 102 and the compression element 104 are assembled together and elastically supported in the sealed container 101 by a plurality of coil springs 108.

  Next, the main configuration of the compression element 104 will be described.

  In the shaft 110, a flange portion 114 is formed at the tip of the main shaft portion 112, and an eccentric shaft portion 116 extending in the axial direction parallel to the axis of the main shaft portion 112 is formed in the flange portion 114.

  The cylinder block 120 is casted, and a compression chamber 122 on the cylinder and a bearing 124 that supports the main shaft portion 112 of the shaft 110 in the vertical direction are formed. The piston 126 is fitted in the compression chamber 122 so as to reciprocate. The piston 126 and the eccentric shaft portion 116 are connected by a connecting rod 128.

  The thrust bearing 130 is disposed between the lower surface 132 of the flange portion 114 and the upper end surface 134 of the bearing 124 and receives a load acting mainly on the shaft 110 in the thrust direction (vertical downward direction).

  The shaft 110 has an oil supply mechanism 138 that is immersed in the oil 106 stored in the sealed container 101 at the lower end 136, and a part of the oil 106 pumped up by the oil supply mechanism 138 is transferred to the main shaft portion 112 at the upper end surface 134. It has the oil supply groove | channel 140 led to.

  The electric element 102 includes a stator 142 fixed below the cylinder block 120 and a rotor 144 fixed to the main shaft portion 112 by shrink fitting or the like.

  The thrust bearing 130 is generally referred to as a thrust ball bearing, and includes a plurality of balls 152 made of bearing steel such as SUJ2, a cage 154 formed of a resin such as nylon that holds the balls 152, and a ball 152. An upper race 156 and a lower race 158 are provided respectively above and below. The ball 152 is held in a ball storage unit 160 provided in the cage 154, and the ball 152 is so small that the ball 152 can freely roll in the ball storage unit 160 between the ball 152 and the ball storage unit 160. A gap (not shown) is provided.

  On the outer peripheral side 164 of the lower surface 162 of the cage 154, four convex portions 168 that prevent the entire contact between the lower surface 162 of the cage 154 and the upper surface 166 of the lower race 158 are formed evenly, and a contact avoidance mechanism Is forming. The height H of the convex portion 168 is defined by a value calculated by the equation (H <D / 2−T / 2) where D is the diameter of the ball 152 and T is the wall thickness of the cage 154, and during operation. The convex portion 168 is defined so as not to contact the upper surface 166 of the lower race 158 and rotate.

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

  When the electric element 102 is energized from an external power source (not shown), the rotor 144 rotates, and the shaft 110 rotates accordingly, and the movement of the eccentric shaft portion 116 is transferred to the piston 126 via the connecting rod 128. It is transmitted. Accordingly, the piston 126 reciprocates in the compression chamber 122, and the compression element 104 performs a predetermined compression operation.

  At this time, the oil supply mechanism 138 of the shaft 110 pumps up the oil 106 and lubricates each sliding portion (not shown), and a part thereof is supplied from the oil supply groove 140 to the upper end surface 134 to lubricate the thrust bearing 130. To do.

  The thrust bearing 130 supports a vertically downward load due to the weight of the rotor 144 and the crankshaft 110 in a point contact with the ball 152, and reduces the frictional force generated between the lower surface 132 of the flange portion 114 and the upper end surface 134 of the bearing 124. Let For this reason, the input of the hermetic compressor is reduced, and the efficiency is improved.

  When the continuous operation time of the hermetic compressor is increased, the number of sliding between the ball 152 and the ball storage unit 160 is excessively increased, the ball storage unit 160 is worn, and the diameter of the ball storage unit 160 gradually increases. .

  During operation, the cage 154 and the ball 152 both rotate around the shaft 110 even when the diameter of the ball storage portion 160 increases, so that a large centrifugal force is applied to the ball 152 having a larger specific gravity than the cage 154. It has occurred. Therefore, the ball 152 rotates while pressing the outer peripheral wall surface of the ball storage unit 60 outward by centrifugal force. In this state, the cage 154 floats on the upper surface 166 of the lower race 158 and rotates.

  When the operation is stopped, as shown in FIG. 4, the retainer 154 cannot be held on a part of the surface of the ball 152 due to the increased diameter of the ball storage portion 160, and the upper surface of the lower race 158 Slide down to 166.

  However, in the first embodiment, the lower surface 162 of the cage 154 has a convex portion 168 that forms a contact avoidance mechanism for preventing the entire contact between the lower surface 162 of the cage 154 and the upper surface 166 of the lower race 158. Since the outer peripheral side 164 is uniformly formed at four locations, the retainer 154 is supported in a partial contact state by the convex portion 168 on the upper surface 166 of the lower race 158 without contacting the entire surface of the lower race 158.

  Therefore, even when the retainer 154 rotates on the upper surface 166 of the lower race 158 at the time of starting the compressor, the retainer 154 and the lower race 158 are not in full contact with each other, so that the frictional resistance can be kept small. As a result, it is possible to prevent the lower surface 162 of the retainer 154 from being worn and the strength of the retainer 154 from being deteriorated, and to realize a highly efficient and highly reliable hermetic compressor that suppresses an increase in input. be able to.

  Further, since the convex portion 168 is formed on the outer peripheral side 164 of the lower surface 162 of the cage 154, centrifugal force is applied from the inside of the cage 154 to between the cage 154 and the lower race 158 by the oil supply mechanism 138 of the shaft 110. The oil 106 supplied while being scattered at the position hits the convex portion 168 and drops. Therefore, the balls 152 rolling on the upper surface of the lower race 158 are improved in lubrication and can be further improved in reliability.

  In addition, in this Embodiment 1, it was set as the structure by which the convex part was uniformly formed in the lower surface of the holder | retainer 154, but if it is three or more places, the same effect can be acquired.

(Embodiment 2)
FIG. 5 is an enlarged cross-sectional view of the thrust bearing portion constituting the hermetic compressor according to the second embodiment of the present invention during operation, and FIG. 6 is a plan view of the cage of the thrust bearing portion constituting the hermetic compressor. FIG. 7 is an enlarged cross-sectional view of the thrust bearing portion constituting the hermetic compressor when the operation is stopped after a long time operation.

  In the second embodiment, since the configuration of the compressor excluding the thrust bearing portion is the same as the configuration of the compressor of the first embodiment, the configuration relating to the entire compressor is described in the first embodiment. FIG. 1 used in FIG. 1 and the description thereof are used, and the description thereof is omitted here.

  In the thrust bearing, the same components as those in the first embodiment will be described with the same reference numerals.

  5 to 7, the thrust bearing 130a is generally referred to as a thrust ball bearing, and is formed of a plurality of balls 152 made of bearing steel such as SUJ2 and a resin such as nylon that holds the balls 152. It has a cage 154a and an upper race 156 and a lower race 158 respectively disposed above and below the ball 152. The ball 152 is held in a ball storage portion 160a provided in the cage 154a, and the ball 152 is so small that the ball 152 can freely roll in the ball storage portion 160a between the ball 152 and the ball storage portion 160a. A gap (not shown) is provided.

  On the lower surface 162a of the cage 154a, a convex portion 168a for preventing the entire contact between the lower surface 162a of the cage 154a and the upper surface 166 of the lower race 158 on the center circumference 172 connecting the centers of the lateral widths of the cage 154a is even. Are formed at four locations to form a contact avoidance mechanism. In other words, the center circumference 172 is in a positional relationship overlapping the track on the rolling surface of the lower race 158 where the ball 152 rolls.

  Here, the height H of the convex portion 168a is (H <D / 2−T / 2) as in the first embodiment, where D is the diameter of the ball 152 and T is the thickness of the cage 154a. ) And is defined so that the convex portion 168a does not contact the upper surface 166 of the lower race 158 during driving.

  The operation and action of the thrust bearing 130a configured as described above will be described below.

  When the continuous operation time of the hermetic compressor is increased, the number of sliding between the ball 152 and the ball storage unit 160a is excessively increased, the ball storage unit 160a is worn, and the diameter of the ball storage unit 160a is gradually increased. .

During operation, even if the diameter of the ball storage portion 160a increases, both the cage 154a and the ball 152 rotate around the shaft 110, so that a large centrifugal force is applied to the ball 152 having a larger specific gravity than the cage 154a. It has occurred. Therefore, the ball 152 rotates while pressing the outer peripheral wall surface of the ball storage portion 160a outward with a centrifugal force. In this state, the cage 154a is rotated while floating on the upper surface 166 of the lower race 158.

  When the operation is stopped, as shown in FIG. 7, the retainer 154a cannot be held on a part of the surface of the ball 152 due to the diameter of the ball storage portion 160a being widened, and the upper surface of the lower race 158 Slide down to 166.

  However, in the second embodiment, on the center circumference 172 (the track on the rolling surface of the lower race 158 on which the ball 152 rolls) that connects the lower surface 162a of the cage 154a to the center of the lateral width of the cage 154a. In addition, since the convex portions 168a are uniformly formed at four places, the retainer 154a is supported in a partial contact state by the convex portions 168a on the upper surface 166 of the lower race 158 without contacting the entire surface of the lower race 158.

  Therefore, even when the cage 154a rotates on the upper surface 166 of the lower race 158 at the time of starting the compressor, the cage 154a and the lower race 158 are not in full contact with each other, so that the frictional resistance can be kept small. As a result, it is possible to prevent the lower surface 162 of the cage 154a from being worn and the strength of the cage 154 from being deteriorated, and to realize a highly efficient and highly reliable hermetic compressor that suppresses an increase in input. be able to.

  Further, at the initial stage of starting the compressor, the convex portion 168a is formed on the lower surface 162a of the cage 154a on the center circumference 172 connecting the centers of the lateral widths of the cage 154a. Slip around the raceway 158 raceway. As a result, abrasion powder and minute dust remaining on the rolling surface at the time of activation can be removed, and damage and wear of the ball 152 and the lower race 158 can be prevented, and reliability can be improved.

  In addition, in this Embodiment 2, although it was set as the structure by which the convex part was uniformly formed in the lower surface of the holder | retainer 154a, if 3 or more places, the same effect can be acquired.

(Embodiment 3)
FIG. 8 is an enlarged cross-sectional view of the thrust bearing portion that constitutes the hermetic compressor according to the third embodiment of the present invention, and FIG. 9 is a plan view of the cage of the thrust bearing portion that constitutes the hermetic compressor. FIG. 10 is an enlarged cross-sectional view of the thrust bearing portion constituting the hermetic compressor when the operation is stopped after long-time operation.

  Also in the third embodiment, since the configuration of the compressor excluding the thrust bearing portion is the same as the configuration of the compressor of the first embodiment, the configuration relating to the whole compressor is described in the first embodiment. FIG. 1 used in FIG. 1 and the description thereof are used, and the description thereof is omitted here.

  In the thrust bearing, the same components as those in the first embodiment will be described with the same reference numerals.

  8 to 10, the thrust bearing 130b is generally referred to as a thrust ball bearing, and is formed of a plurality of balls 152 made of bearing steel such as SUJ2 and a resin such as nylon that holds the balls 152. It has a cage 154b and an upper race 156 and a lower race 158 respectively disposed above and below the ball 152. The ball 152 is held in a ball storage unit 160b provided in the cage 154b so that the ball 152 can freely roll in the ball storage unit 160b between the ball 152 and the ball storage unit 160b. A minute gap (not shown) is provided.

  On the inner peripheral side 174 of the lower surface 162b of the retainer 154b, four convex portions 168b that prevent the entire contact between the lower surface 162b of the retainer 154b and the upper surface 166 of the lower race 158 are formed evenly to avoid contact. Forming mechanism. The height H of the convex portion 168b is expressed by the equation (H <D / 2−T / 2) as in the first embodiment, where D is the diameter of the ball 152 and T is the thickness of the cage 154b. It is defined that the convex portion 168b does not contact the upper surface 166 of the lower race 158 during driving.

  The operation and action of the thrust bearing 130b configured as described above will be described below.

  When the continuous operation time of the hermetic compressor is increased, the number of sliding between the ball 152 and the ball storage unit 160b is excessively increased, the ball storage unit 160b is worn, and the diameter of the ball storage unit 160b gradually increases. .

  During operation, even if the diameter of the ball storage portion 160b increases, both the ball 152 and the cage 154b rotate around the shaft 110, so that a large centrifugal force is applied to the ball 152 having a larger specific gravity than the cage 154b. It has occurred. Therefore, the ball 152 rotates while pressing the outer peripheral wall surface of the ball storage portion 160b outward with a centrifugal force. In this state, the cage 154b is rotated while floating on the upper surface 166 of the lower race 158.

  When the operation is stopped, as shown in FIG. 10, the retainer 154 b cannot be held on a part of the surface of the ball 152 due to the diameter of the ball storage portion 160 b expanding, and the upper surface of the lower race 158 Slide down to 166.

  However, in the third embodiment, since the convex portions 168b are uniformly formed on the inner peripheral side 174 of the lower surface 162b of the retainer 154b, the retainer 154b comes into full contact with the lower race 158. Instead, the upper surface 166 of the lower race 158 is supported in a partial contact state by the convex portion 168b.

  Therefore, even when the cage 154b rotates on the upper surface 166 of the lower race 158 at the time of starting the compressor, the cage 154b and the lower race 158 are not in full contact with each other, so that the frictional resistance can be kept small. As a result, it is possible to prevent the lower surface 162 of the cage 154b from being worn and the strength of the cage 154 from being deteriorated, and to realize a highly efficient and highly reliable hermetic compressor that suppresses an increase in input. be able to.

  Further, since the convex portions 168b forming the contact avoidance mechanism are equally formed at four locations on the inner peripheral side 174 of the lower surface 162b of the retainer 154b, the outer peripheral side 164b between the retainer 154b and the lower race 158 It has a configuration without a shield. Therefore, the oil 106 supplied by the oil supply mechanism 138 of the shaft 110 rebounds after being supplied to the piston 126 and the connecting rod 128, and the oil 106 that rebounds from the outer periphery side of the retainer 154 b from the retainer 154 b and the lower race 158. It is easy to be supplied in between. As a result, the lubrication of the ball 152 rolling on the upper surface of the lower race 158 is improved, and the reliability of the ball 152 and the lower race 158 can be further improved.

  In addition, in this Embodiment 3, it was set as the structure by which the convex part was uniformly formed in the lower surface of the holder | retainer 154b, but if it is three or more places, the same effect can be acquired.

(Embodiment 4)
FIG. 11 is an enlarged cross-sectional view of the thrust bearing portion that constitutes the hermetic compressor according to the fourth embodiment of the present invention, and FIG. 12 is a plan view of the cage of the thrust bearing portion that constitutes the hermetic compressor. FIG. 13 is an enlarged cross-sectional view of the thrust bearing portion constituting the hermetic compressor when the operation is stopped after long-time operation.

  Also in the fourth embodiment, since the configuration of the compressor excluding the thrust bearing portion is the same as the configuration of the compressor of the first embodiment, the configuration relating to the whole compressor is described in the first embodiment. FIG. 1 used in FIG. 1 and the description thereof are used, and the description thereof is omitted here.

  In the thrust bearing, the same components as those in the first embodiment will be described with the same reference numerals.

  11 to 13, the thrust bearing 230 is generally called a thrust ball bearing, and is formed of a plurality of balls 152 made of bearing steel such as SUJ2 and a resin such as nylon that holds the balls 152. It has a cage 254 and an upper race 156 and a lower race 158 respectively disposed above and below the ball 152. The ball 152 is held in a ball storage unit 260 provided in the cage 254 so that the ball 152 can freely roll in the ball storage unit 260 between the ball 152 and the ball storage unit 260. A minute gap (not shown) is provided.

  Four holders 280 are equally provided on the outer peripheral wall of the cage 254, and the lower surface 282 of the holder 280 is formed to be flush with the lower surface 262 of the cage 254.

  Then, on the lower surface 282 of the holder 280, convex portions 268 that prevent the entire surface contact between the lower surface 262 of the holder 254 and the upper surface 166 of the lower race 158 are formed, thereby forming a contact avoidance mechanism. The height H of the convex portion 268 is an expression of (H <D / 2−T / 2) as in the first embodiment, where D is the diameter of the ball 152 and T is the thickness of the cage 254. It is defined that the convex portion 268 does not contact the upper surface 166 of the lower race 158 during driving.

  The operation and action of the thrust bearing 230 configured as described above will be described below.

  If the continuous operation time of the hermetic compressor is increased, the number of sliding between the ball 152 and the ball storage unit 260 is excessively increased, the ball storage unit 260 is worn, and the diameter of the ball storage unit 260 gradually increases. .

  During operation, the cage 254 and the ball 152 both rotate about the shaft 110 even if the diameter of the ball storage portion 260 increases, so that a large centrifugal force is exerted on the ball 152 having a larger specific gravity than the cage 254. It has occurred. Therefore, the ball 152 rotates while pressing the outer peripheral wall surface of the ball storage portion 260 toward the outside with centrifugal force. In this state, the cage 254 is rotated while floating above the upper surface of the lower race 158.

  When the operation is stopped, as shown in FIG. 13, the retainer 254 cannot be held on a part of the surface of the ball 152 due to the increased diameter of the ball storage portion 260, and the upper surface of the lower race 158. It slips down to 166.

  However, in the fourth embodiment, since the convex portions 268 are formed on the lower surfaces 282 of the four holders 280 provided on the outer peripheral wall of the retainer 254, the lower surface 262 of the retainer 254 and the lower race 158 are formed. Full contact with the top surface 166 is prevented. Therefore, the retainer 254 is supported in a partial contact state by the convex portion 268 on the upper surface 166 of the lower race 158 without contacting the entire surface of the lower race 158.

  Therefore, even when the retainer 254 rotates on the upper surface 166 of the lower race 158 at the time of starting the compressor, the retainer 254 and the lower race 158 are not in full contact with each other, so that the frictional resistance can be kept small. As a result, it is possible to prevent the lower surface 262 of the cage 254 from being worn and the strength of the cage 254 from deteriorating, and to realize a highly efficient and highly reliable hermetic compressor that suppresses an increase in input. be able to.

  Moreover, since the strength of the cage 254 can be increased by providing a plurality of holders 280 on the outer peripheral wall of the cage 254, even if the operation time becomes long and the ball storage portion 260 is worn, Strength deterioration can be suppressed.

  Further, even when the cage 254 is exposed to a high temperature state, the holder 280 serves as a cooling fin and suppresses the temperature rise of the cage 254. Therefore, the thermal strain of the cage 254 is suppressed, and the cage 254 Durability can be improved.

  In the fourth embodiment, the holder 254 is configured such that four holders 280 having convex portions on the lower surface are formed evenly, but the same effect can be obtained if there are three or more.

(Embodiment 5)
FIG. 14 is an enlarged cross-sectional view of the thrust bearing portion constituting the hermetic compressor according to the fifth embodiment of the present invention during operation, and FIG. 15 shows the thrust bearing portion constituting the hermetic compressor after long-time operation. It is a cross-sectional enlarged view at the time of operation stop in.

  Also in the fifth embodiment, since the configuration of the compressor excluding the thrust bearing portion is the same as the configuration of the compressor of the first embodiment, the configuration relating to the whole compressor is described in the first embodiment. FIG. 1 used in FIG. 1 and the description thereof are used, and the description thereof is omitted here.

  In the thrust bearing, the same components as those in the first embodiment will be described with the same reference numerals.

  14 and 15, the thrust bearing 330 is generally called a thrust ball bearing, and is formed of a plurality of balls 152 made of bearing steel such as SUJ2 and a resin such as nylon that holds the balls 152. It has a cage 354 and an upper race 156 and a lower race 158 respectively disposed above and below the ball 152. The ball 152 is held in a ball storage portion (not shown) provided in the cage 354, and the ball 152 is placed between the ball 152 and the ball storage portion as in the first embodiment. A minute gap (not shown) is provided so that it can freely roll in the storage portion.

  The lower surface 362 of the cage 354 is formed on an inclined surface so that the vertical thickness (axial direction) of the cage 354 increases from the inner circumferential side 374 toward the outer circumferential side 364. Therefore, the edge of the outer peripheral side 364 of the lower surface 362 in the cage 354 is in line contact with the upper surface 166 of the lower race 158, thereby forming a contact avoidance mechanism for preventing full contact.

  The operation and action of the thrust bearing 330 configured as described above will be described below.

  When the continuous operation time of the hermetic compressor is increased, the number of sliding between the ball 152 and the ball storage portion is excessively increased, the ball storage portion is worn, and the diameter of the ball storage portion gradually increases.

  During operation, the cage 354 and the ball 152 both rotate around the shaft 110 even if the diameter of the ball storage portion increases, so that a large centrifugal force is generated in the ball 152 having a larger specific gravity than the cage 354. doing. Therefore, the ball 152 rotates while pressing the outer peripheral wall surface of the ball storage portion toward the outside with centrifugal force. In this state, the cage 354 floats on the upper surface of the lower race 158 and rotates.

  When the operation is stopped, as shown in FIG. 15, the retainer 354 cannot be held on a part of the surface of the ball 152 due to the increased diameter of the ball storage portion, and the upper surface 166 of the lower race 158 is not retained. Slip down.

  However, in the fifth embodiment, the lower surface 362 of the retainer 354 is inclined from the inner peripheral side 374 toward the outer peripheral side 364 so that the vertical thickness (axial direction) of the retainer 354 increases. As a result, the distance between the lower surface 362 and the upper surface 166 of the lower race 158 is such that the outer peripheral side 364 is shorter than the inner peripheral side 374, so that the retainer 354 does not come into full contact with the lower race 158. Only the outer peripheral side 364 makes line contact with the upper surface 166 of the lower race 158 and is supported.

  Therefore, even when the retainer 354 rotates on the upper surface 166 of the lower race 158 at the time of starting the compressor, the retainer 354 and the lower race 158 are not in full contact with each other, so that the frictional resistance can be kept small. As a result, it is possible to prevent the lower surface 362 of the retainer 354 from being worn and the strength of the retainer 354 from being deteriorated, and to realize a highly efficient and highly reliable hermetic compressor that suppresses an increase in input. be able to.

  Further, since the inner circumferential side 374 is thinner than the outer circumferential side 364 in the vertical direction (axial direction) thickness of the cage 354, the surface of the ball 152 is exposed from the cage 354 as much as the inner circumferential side 374. Therefore, the oil 106 supplied from the oil supply mechanism 138 of the shaft 110 to the inside of the cage 354 easily adheres to the ball 152. As a result, the lubrication of the ball 152 rolling on the upper surface 166 of the lower race 158 is improved, and the reliability can be improved.

  As described above, since the hermetic compressor according to the present invention has the contact avoidance mechanism formed in the cage, it can suppress an increase in input and improve the reliability. Therefore, the vending machine, the freezer showcase, the dehumidifier It can also be used for machines.

DESCRIPTION OF SYMBOLS 101 Airtight container 102 Electric element 104 Compression element 106 Oil 110 Shaft 112 Main shaft part 114 Head part 116 Eccentric shaft part 120 Cylinder block 122 Compression chamber 124 Bearing 126 Piston 128 Connecting rod 130 Thrust bearing 130a Thrust bearing 130b Thrust bearing 134 Upper end surface 142 Stator 144 Rotor 152 Ball 154 Cage 154a Cage 154b Cage 156 Upper race 158 Lower race 162 Lower surface 162a Lower surface 162b Lower surface 164 Outer peripheral side 164b Outer peripheral side 166 Upper surface 168 Convex portion 168a Convex portion 168b Convex portion 172 Peripheral side 230 Thrust bearing 254 Cage 268 Protruding part 280 Holder 282 Lower surface 330 Thrust bearing 354 Cage 362 Lower surface 364 Outer side 37 The inner circumferential side

Claims (5)

An oil container, an electric element including a stator and a rotor, and a compression element driven by the electric element are accommodated in a sealed container, and the compression element is formed at a main shaft portion and a tip of the main shaft portion. A flange portion, a shaft that is formed through the flange portion and includes an eccentric shaft portion that extends in an axial direction parallel to the axial center of the main shaft portion, a cylinder block that forms a compression chamber, and the cylinder block And a bearing that supports the shaft; a piston that reciprocates in the compression chamber; a connecting rod that connects the piston and the eccentric shaft portion; and a flange portion and an upper end surface of the bearing. The thrust bearing is provided with a plurality of balls, a resin-made cage that holds the balls in a freely rolling manner in a ball housing portion, and upper and lower portions of the balls, respectively. A configuration including a race and lower race on which, furthermore, the retainer, the contact avoidance mechanism for preventing entire contact with the upper surface of the lower race and the lower surface of the retainer is provided, the contact avoidance mechanism, the A hermetic compressor comprising a convex portion protruding from the lower surface of the cage, wherein the convex portion is provided at a position overlapping a track on a rolling surface of a lower race on which the ball rolls . The hermetic compressor according to claim 1, wherein the contact avoidance mechanism is configured by a convex portion protruding from a lower surface of the cage, and the convex portion is provided on an outer peripheral side of the cage. 2. The hermetic compressor according to claim 1, wherein the contact avoidance mechanism is configured by a convex portion protruding from a lower surface of the cage, and the convex portion is provided on an inner peripheral side of the cage. The hermetic compressor according to claim 1, wherein the contact avoidance mechanism includes a holder protruding from an outer peripheral side wall of the cage and a convex portion protruding from a lower surface of the holder. 2. The hermetic compressor according to claim 1, wherein the contact avoidance mechanism is formed by an inclined surface that increases in thickness in the axial direction of the cage from the inner circumferential side toward the outer circumferential side on the lower surface of the cage.