JP4872839B2 - Hermetic compressor - Google Patents

Description

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

  In recent years, with regard to hermetic compressors used in refrigeration apparatuses such as refrigerators and refrigerators, high efficiency, low noise, and high reliability for reducing power consumption are desired.

  Conventionally, this type of hermetic compressor employs a thrust ball bearing for the purpose of improving efficiency and has a structure in which a shaft can freely rotate with respect to a main bearing (see, for example, Patent Document 1).

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

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

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

  A cylindrical compression chamber 22 is formed in the cylinder block 20 constituting the compression element 4, and a piston 24 is reciprocally inserted into the compression chamber 22. A main bearing 26 is fixed to the upper part of the cylinder block 20, and a thrust surface 28 is formed above the main bearing 26.

  The shaft 30 includes a main shaft portion 34 that is pivotally supported by the main bearing 26 in the vertical direction and has a spiral oil supply groove 32 on the outer periphery, and an eccentric shaft portion 36 formed below the main shaft portion 36. A pipe-shaped oil supply pipe 42 is press-fitted into an oil supply hole (not shown) formed in the lower end 38 of the shaft, and the eccentric shaft portion 36 and the piston 24 are connected by a connection mechanism 44.

  One end of the oil supply pipe 42 communicates with the spiral oil supply groove 32 from the oil supply hole, and a lower end opening 46 opens into the lubricating oil 6.

  The electric element 2 is composed of a stator 52 fixed above the cylinder block 20 and provided with a winding 50, and a rotor 54 fixed to the main shaft portion 34 of the shaft 30 by shrink fitting or the like.

  A bore plane 58 is formed in a counter bore 56 that is a recess in the lower portion 55 of the rotor 54, and a thrust surface 28 is formed at the upper end of the main bearing 26. Between the bore plane 58 and the thrust surface 28 in the counter bores 56, a thrust ball bearing 60 is disposed to support the shaft 30.

  The thrust ball bearing 60 includes a plurality of balls 62, a holder portion 64 that holds the balls 62, and an upper race 66 and a lower race 68 that are respectively disposed above and below the ball 62. The upper race 66 rotates. The lower race 68 is in contact with the thrust surface 28 of the main bearing 26.

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

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

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

  At this time, the oil supply pipe 42 draws up the lubricating oil 6 by centrifugal force and lubricates each sliding portion (not shown), and a part thereof is supplied from the helical oil supply groove 32 to the thrust surface 28 and is thrust ball bearing 60. Lubricate.

The weight of the shaft 30 and the rotor 54 is supported by a thrust ball bearing 60, and since the ball 62 rolls between the upper race 66 and the lower race 68 when the shaft 30 rotates, the torque for rotating the shaft 30 is a thrust slide bearing. Smaller than Therefore, loss in the thrust bearing can be reduced, input can be reduced, and high efficiency can be achieved.
JP-A 61-53474

  However, in the conventional configuration, when the hermetic compressor is operated for a long time, the upper race 66, the bore plane 58 with which the upper race 66 is in contact, and the shaft 30 on the inner diameter side of the upper race 66 slide. There was a possibility of wearing or scuffing.

  Further, due to sliding, scratching, and abrasion of the upper race 66, the bore plane 58, and the shaft 30, the input of the compressor is increased and the efficiency is lowered, or the wear powder slides with the lubricating oil 6 each time. There is a possibility that reliability may be reduced by being led to the part.

  The present invention solves the above-described conventional problems, and prevents the sliding at the contact portion between the upper race 66 and the bore plane 58 and the sliding between the inner diameter of the upper race 66 and the outer diameter of the shaft 30 in the thrust ball bearing 60. Further, it is possible to provide a highly efficient and highly reliable hermetic compressor that suppresses the occurrence of wear at the contact portion between the upper race 66 and the bore plane 58 and the wear at the inner diameter of the upper race 66 and the outer diameter of the shaft 30 and suppresses increase in input. The purpose is to do.

  In order to solve the above conventional problems, the hermetic compressor of the present invention is provided with a stopper between the upper race and the shaft so that the upper race and the shaft rotate integrally. Even during long-term driving, the upper race and the shaft rotate together, preventing slippage between the upper race and the bore plane. In this case, it is possible to suppress an increase in input and wear due to sliding.

  Further, since it is possible to prevent slippage between the upper race and the shaft, an increase in input due to sliding and generation of wear can be suppressed even at the inner diameter of the upper race and the outer diameter of the shaft. Have

  The hermetic compressor of the present invention is provided with a stopper between the upper race and the shaft so that the upper race and the shaft rotate integrally, and wear due to sliding between the upper race and the bore plane. Further, it is possible to provide a highly efficient and reliable hermetic compressor that can suppress the occurrence of wear due to sliding between the upper race and the shaft, and suppress an increase in input.

  According to the first aspect of the present invention, the lubricating oil is stored in a sealed container, and an electric element having a stator and a rotor, and a compression element driven by the electric element and disposed below the electric element, The compression element has an eccentric shaft portion and a main shaft portion, the shaft to which the rotor is fixed, a cylinder block having a cylindrical compression chamber, a piston that reciprocates in the compression chamber, A coupling mechanism that couples the piston and the eccentric shaft portion, a main bearing that is formed in the cylinder block and supports the main shaft portion of the shaft, and a thrust provided between the rotor and the main bearing A ball bearing, and the thrust ball bearing includes a plurality of balls, a holder portion for holding the balls, and an upper race and a lower race respectively disposed above and below the balls. A stopper is provided between the upper race and the shaft so that the upper race and the shaft rotate integrally, and the upper race and the shaft are integrated even during start-up and long-term driving. To prevent slippage between the upper race and the bore plane, or between the upper race and the shaft, so that the contact portion between the upper race and the bore plane, the upper race inner diameter and the shaft outer diameter can be prevented. Therefore, it is possible to suppress an increase in input and wear due to sliding, and thus it is possible to provide a highly efficient and highly reliable hermetic compressor that suppresses an increase in input.

  According to a second aspect of the present invention, in the first aspect of the present invention, the stop portion is a concave portion that is fitted to the convex portion provided on the inner peripheral portion of the upper race and the convex portion provided on the shaft. In the process of fixing the rotor to the main shaft of the shaft assembled to the main bearing by shrink fitting, etc., the lower race, the thrust ball bearing, and the upper race are placed on the thrust surface of the main bearing. 2. The projecting portion of the inner peripheral portion can be inserted while being fitted into the recessed portion of the shaft, and finally the rotor can be shrink-fitted, so that the assembling operation is easy and the working efficiency is improved. In addition to the effects of the invention, the working time can be further shortened and the productivity is good.

  The invention according to claim 3 is the invention according to claim 1 or 2, wherein the surface hardness of the upper race is higher than the surface hardness of the bore plane of the rotor, and the surface hardness of the lower race is the thrust of the main bearing. Since the upper and lower races are thin plates, the surface hardness can be easily secured by heat treatment, etc., and the flatness of the rotor bore plane and main bearing thrust surface is increased. Even if it is bad, the hardness of the upper and lower races can prevent the upper and lower races from being deformed. Therefore, the plane of the upper and lower races, which are in contact with the ball of the thrust ball bearing, is secured. In addition to the effects of the invention of claim 1 or claim 2, it is possible to further prevent the rolling surface of the ball from being worn and to improve the reliability of the thrust ball bearing. Rukoto can.

  The invention according to claim 4 is the invention according to any one of claims 1 to 3, wherein the surface hardness of the ball of the thrust ball bearing is higher than the surface hardness of the upper race and the lower race. In addition to the effects of the invention according to any one of claims 1 to 3, the ball can be further prevented from wearing before the rolling surfaces of the upper race and the lower race. It is possible to prevent the rolling surfaces of the upper race and the lower race from being damaged or worn due to the wear of the upper race, and the reliability of the thrust ball bearing can be improved.

  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)
1 is a longitudinal sectional view of a hermetic compressor according to Embodiment 1 of the present invention, FIG. 2 is an enlarged view of a main part of FIG. 1, FIG. 3 is a perspective view of the shaft of FIG. 1, and FIG. It is a perspective view of a race.

  1 to 4, an electric element 102 including a stator 151 and a rotor 152 and a compression element 104 that is rotationally driven by the electric element 102 are housed in a sealed container 101, and lubricated at the bottom. Oil 106 is stored. The electric element 102 and the compression element 104 are integrally assembled to form a compression mechanism 108, and the compression mechanism 108 is elastically supported in the sealed container 101 by a plurality of coil springs (not shown).

  A cylindrical compression chamber 122 is formed in the cylinder block 120 constituting the compression element 104, and a piston 124 is fitted into the compression chamber 122 so as to reciprocate. A main bearing 126 is fixed to the upper part of the cylinder block 120, and a thrust surface 128 is formed above the main bearing 126.

  The shaft 130 includes a main shaft portion 134 that is pivotally supported by the main bearing 126 in the vertical direction and has a spiral oil supply groove 132 on the outer periphery, and an eccentric shaft portion 136 formed below the main shaft portion 136. An oil supply pipe 142 formed of a steel pipe is press-fitted into an oil supply hole (not shown) formed in the lower end 138 of the nozzle 138, and the eccentric shaft portion 136 and the piston 124 are connected by a connection mechanism 144.

  The oil supply pipe 142 has one end communicating with the spiral oil supply groove 132 from the lower end 138 of the eccentric shaft part 136, and the lower end opening 146 of the oil supply pipe 142 is curved on an extension line of the central axis 148 of the main shaft part 134. 106 is open.

  The electric element 102 is formed of an easy-to-handle induction motor that can be rotated only by being connected to a commercial power source. The electric element 102 is fixed above the cylinder block 120 with a bolt (not shown) and includes a winding 151. And a rotor 152 fixed to the main shaft portion 134 of the shaft 130 by shrink fitting or the like.

  An annular bore plane 166 provided substantially perpendicular to the central axis 148 is formed in the counter bore 164 which is a recess of the lower portion 162 of the rotor 152 laminated with electromagnetic steel plates, and is a main bearing casted with aluminum. An annular thrust surface 128 provided substantially at a right angle to the central axis 148 is formed at the end 127 of 126.

  A thrust ball bearing 170 is disposed between the bore plane 166 in the counter bore 164 and the thrust surface 128 to support the weight of the shaft 130 and the rotor 152.

  The thrust ball bearing 170 includes a plurality of balls 172, a holder portion 174 that holds the balls 172, and an upper race 176 and a lower race 178 that are respectively disposed above and below the balls 172. The upper race 176 is in contact with the bore plane 166 of the rotor 152, and the lower race 178 is in contact with the thrust surface 128 of the main bearing 126.

  The ball 172 is formed of a carburized and hardened bearing steel with high wear resistance, and the surface hardness is in the range of HRC 60-70. The upper race 176 and the lower race 178 are heat treated carbon steel having a higher surface hardness and higher wear resistance than the electromagnetic steel plate forming the rotor 152 and the aluminum casting forming the main bearing 126. The surface hardness is in the range of HRC58-68. The surface hardness of the ball 172 is set slightly higher than the surface hardness of the upper race 176 and the lower race 178.

  The upper race 176 includes a projecting portion 180 having a part of the inner periphery that is a straight line. 182.

  The convex portion 180 of the upper race 176 and the concave portion 182 of the shaft 130 are assembled and assembled to constitute a stopper 184.

  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 152 rotates, and the shaft 130 rotates accordingly, and the rotational movement of the eccentric shaft portion 136 is transmitted via the coupling mechanism 144. By being transmitted to the piston 124, the piston 124 reciprocates in the compression chamber 122, and the compression element 104 performs a predetermined compression operation.

  As a result, the refrigerant gas is sucked into the compression chamber 122 from the cooling system (not shown), compressed, and then discharged to the cooling system again.

  At this time, one end of the oil supply pipe 142 is press-fitted into the lower end 138 of the eccentric shaft portion 136, and the lower end opening 146 is curved on an extension line of the central axis 148 of the main shaft portion 134. Thus, the lubricating oil 106 is pumped up and each sliding portion is lubricated, and a part thereof is supplied to the thrust surface 128 from the spiral oil supply groove 132 to lubricate the thrust ball bearing 170.

  The weight of the shaft 130 and the rotor 152 is supported by the thrust ball bearing 170, and the ball 172 rolls between the upper race 176 and the lower race 178 when the shaft 130 rotates. Smaller than a plain bearing. Therefore, loss in the thrust bearing can be reduced, input can be reduced, and high efficiency can be achieved.

  Next, by providing a stopper 184 between the upper race 176 and the shaft 130, wear due to sliding between the upper race 176 and the bore plane 166 and wear due to sliding between the upper race 176 and the shaft 130 are generated. The mechanism of suppression will be described.

  Since the convex portion 180 provided on the inner peripheral portion of the upper race 176 and the concave portion 182 provided on the outer peripheral portion of the shaft 130 are fitted, the upper race 176 is completely connected to the rotor 152 and the shaft 130. Therefore, the upper race 176, the shaft 130, and the bore plane 166 of the rotor 152 are not slid and rubbed, and the contact portion is not worn.

  In particular, the wear can be prevented in the bore plane 166 having a relatively low hardness and easy to wear.

  Further, the larger the flatness value of the bore plane 166 is, the worse the accuracy is, the wear-out the conventional hermetic compressor without the stop portion 184, but the bore plane 166 is worn. However, by providing the stop portion 184, the bore plane is improved. The wear of the bore plane 166 could be prevented without increasing the accuracy of the flatness of 166.

  This is because if the flatness of the bore plane 166 is poor and scratches are present, the contact area between the upper race 176 and the bore plane 166 will be reduced, the friction coefficient will be reduced, and the upper race 176 will be It is thought that this is because the conventional disadvantage that the slip was generated without rotating in synchronization with the rotation of the shaft 130 could be solved.

  Further, the larger the inclination of the bore plane 166, the more the conventional hermetic compressor without the stop portion 184 was scratched on the outer surface of the shaft 130 on the inner periphery of the upper race 176, and it was worn in the worst case. However, by providing the stopper 184, it was possible to prevent the outer surface of the shaft 130 from being scratched and worn without improving the inclination of the bore plane 166.

  This is because if the bore plane 166 is slightly inclined, the upper race 176 contacts the outer surface of the shaft 130, so that the upper race 176 does not rotate in synchronization with the rotation of the shaft 130, and the inner circumference of the upper race 176 This is considered to be due to the fact that the conventional disadvantage that the shaft 130 with low hardness was worn due to sliding with the outer surface of the shaft 130 could be solved.

  Further, since no friction due to rotation occurs between the upper race 176 and the bore plane 166 of the shaft 130 and the rotor 152, the input loss is small, the efficiency is high, and the noise is also quiet.

  The surface hardness of the upper race 176 is higher than the surface hardness of the bore plane 166 of the rotor 152, and the surface hardness of the lower race 178 is higher than the surface hardness of the thrust surface 128 of the main bearing 126. Since the 176 and the lower race 178 have a thin plate shape, the surface hardness can be easily ensured by heat treatment or the like, and the productivity can be high and the manufacturing cost can be reduced.

  Even when the flatness of the bore plane 166 of the rotor 152 and the thrust surface 128 of the main bearing 126 is poor, the upper race 176 and the lower race 178 have high hardness. The deformation along the thrust surface 128 can be prevented, and the flat surfaces of the upper race 176 and the lower race 178 that are the contact portions of the thrust ball bearing 170 with the ball 172 can be secured.

  As a result, it is possible to prevent the upper race 176 and the lower race 178 from which the ball 172 rolls from being worn, and to improve the reliability.

  Further, the ball 172, the upper race 176, and the lower race 178 have high surface hardness, and have excellent wear resistance. Further, the surface hardness of the ball 172 is set slightly higher than the surface hardness of the upper race 176 and the lower race 178, and the ball 172 is prevented from being worn before the upper race 176 and the lower race 178 that roll. can do.

  Therefore, it is possible to prevent the surface of the ball 172 from being rough and scratching or wearing the rolling surfaces of the upper race 176 and the lower race 178, and the surfaces of the upper race 176 and the lower race 178 are accelerated at the time of wear. There is nothing.

  Next, assembly of the thrust ball bearing 170 will be described.

  The stopper 184 in the first embodiment is composed of a projecting portion 180 provided on the inner peripheral portion of the upper race 176 and a recessed portion 182 provided on the shaft 130 so as to be fitted to the projecting portion 180. ing.

  Therefore, the lower race 178 and the plurality of balls 172 are held on the thrust surface 128 of the main bearing 126 in the process of fixing the rotor 152 to the main shaft portion 134 of the shaft 130 integrally assembled with the main bearing 126 by shrink fitting or the like. The holder portion 174 and the convex portion 180 on the inner periphery of the upper race 176 are inserted into the concave portion 182 of the shaft 130 while being inserted, and finally the rotor 152 is shrink-fitted to the main shaft portion 134 of the shaft 130. Assembling is possible, and there are no complicated assembly jigs or complicated procedures. Assembling work is easy, work efficiency is good, and productivity is good.

  In addition, about the stop part 184 of the shaft 130 and the upper race 176, another Example can also be considered.

(Embodiment 2)
FIG. 5 is a perspective view of the shaft of the hermetic compressor according to the second embodiment of the present invention, and FIG. 6 is a perspective view of the upper race of the hermetic compressor according to the second embodiment. In addition, the same code | symbol is attached | subjected about the same structure as the said Embodiment 1. FIG.

  As shown in FIGS. 5 and 6, for the stopper portion 185 of the shaft 130 and the upper race 176, the spiral oil supply groove 132 provided on the outer periphery of the main shaft portion 134 of the shaft 130 is extended to serve as the recessed portion 186. Further, it may be configured by a projecting portion 188 provided on the inner peripheral portion of the upper race 190 so as to be fitted to the recessed portion 186 of the shaft 130.

  As described above, the effectiveness of the upper race 176 rotating in complete synchronization with the rotor 152 and the shaft 130 has been described. Similarly, the stoppers 184 and 185 are formed between the lower race 178 and the main bearing 126. Thus, rubbing and sliding of the lower race 178 and the thrust surface 128 of the main bearing 126 are avoided, wear is prevented and reliability is improved, and loss of input due to rubbing and sliding is reduced and higher efficiency is achieved. This is effective for reducing noise.

  As described above, the hermetic compressor according to the present invention suppresses an increase in input by providing a stopper between the upper race and the shaft so that the upper race and the shaft rotate integrally. Since a highly efficient and highly reliable hermetic compressor can be provided, it can be applied to applications such as vending machines, refrigeration showcases, and dehumidifiers.

1 is a longitudinal sectional view of a hermetic compressor according to Embodiment 1 of the present invention. The principal part enlarged view of the hermetic type compressor in the embodiment The perspective view of the shaft of the hermetic compressor in the embodiment Perspective view of upper race of hermetic compressor in the same embodiment The perspective view of the shaft of the hermetic compressor in Embodiment 2 of the present invention. Perspective view of upper race of hermetic compressor in the same embodiment Vertical section of a conventional hermetic compressor Enlarged view of the main parts of a conventional hermetic compressor

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Airtight container 102 Electric element 104 Compression element 106 Lubricating oil 120 Cylinder block 122 Compression chamber 124 Piston 126 Main bearing 128 Thrust surface 130 Shaft 134 Main shaft part 136 Eccentric shaft part 144 Connection mechanism 151 Stator 152 Rotor 166 Bore plane 170 Thrust Ball bearing 172 Ball 174 Holder portion 176, 190 Upper race 178 Lower race 180, 188 Protruding portion 182, 186 Concavity portion 184, 185 Stopping portion

Claims (4)

  The lubricating oil is stored in a sealed container, and an electric element including a stator and a rotor and a compression element driven by the electric element and disposed below the electric element are accommodated, and the compression element includes: A shaft having an eccentric shaft portion and a main shaft portion, to which the rotor is fixed, a cylinder block having a cylindrical compression chamber, a piston reciprocating in the compression chamber, the piston and the eccentric shaft portion, A connecting mechanism for connecting the main shaft, a main bearing formed on the cylinder block for supporting the main shaft portion of the shaft, and a thrust ball bearing provided between the rotor and the main bearing. The ball bearing includes a plurality of balls, a holder portion that holds the balls, and an upper race and a lower race that are respectively disposed above and below the balls. As a Yafuto rotate together, the hermetic compressor provided with a stopper portion between the upper race and the shaft.   2. The hermetic compressor according to claim 1, wherein the stopper is configured by a protruding portion provided on an inner peripheral portion of the upper race and a recessed portion fitted to the protruding portion provided on the shaft.   The hermetic compressor according to claim 1 or 2, wherein the surface hardness of the upper race is higher than the surface hardness of the bore plane of the rotor, and the surface hardness of the lower race is higher than the surface hardness of the thrust surface of the main bearing.   The hermetic compressor according to any one of claims 1 to 3, wherein the surface hardness of the ball of the thrust ball bearing is higher than the surface hardness of the upper race and the lower race.

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