JP2014034898A - Sealed compressor, and refrigerator or air conditioner including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent abrasion due to sliding at a contact portion of an upper race and a bore plane of a rotor, and generation of abrasion of an inner diameter of the upper race and an outer diameter of a shaft.SOLUTION: A compression element driven by a stator 52 and a rotor 54, includes: a shaft 30 to which the rotor 54 is fastened; a cylinder block 20; a reciprocating piston 24; a main bearing 26 for journaling the shaft fixed to the cylinder block 20; and a thrust ball bearing 60 disposed between a horizontal face 58 of a lower hollow portion 56 of the rotor 54 and a thrust face 28 of the main bearing 26. The thrust ball bearing 60 includes: an upper race 66 and a lower race 68 respectively disposed at upper and lower portions of balls 62; and stop portions 84 fitted to each other, are disposed between the upper race 66 and a vertical face A of the lower hollow portion 56 of the rotor 54. The stop portions are composed of a projecting portion disposed on an outer peripheral portion of the upper race and a recessed portion disposed on the vertical face of the lower hollow portion of the rotor, and fitted to each other.

Description

  The present invention relates to a hermetic compressor used in an apparatus having a refrigeration cycle such as a refrigerator, an air conditioner, a refrigerated showcase, and a refrigerator or an air conditioner provided with the same.

  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. As a prior art of this type of hermetic compressor, for example, Patent Document 1 employs a thrust ball bearing for the purpose of improving efficiency, and a shaft that drives a piston that reciprocates in a cylinder block is used with respect to the main bearing. A structure that can freely rotate is disclosed.

  The technique disclosed in Patent Document 1 will be described with reference to FIGS. 6 is a longitudinal sectional view showing a main part of a conventional hermetic compressor described in Patent Document 1, FIG. 7 is a perspective view of the shaft shown in FIG. 6, and FIG. 8 is an upper race shown in FIG. FIG.

  6 to 8, the hermetic container of the hermetic compressor accommodates an electric element composed of a stator and a rotor 152 and a compression element that is driven to rotate by the electric element, and lubricates the bottom of the electric element. Oil is stored. A main bearing 126 is fixed to an upper portion of a cylinder block of a compression element having a piston, and a thrust surface 128 is formed above the main bearing 126.

  The shaft 130 includes a main shaft part 134 having a spiral oil supply groove 132 on the outer periphery and an eccentric shaft part 136 formed below the main shaft part 134, and an oil supply pipe 142 is press-fitted into a lower end 138 of the eccentric shaft part 136. The eccentric shaft portion 136 and the piston are connected by a connecting mechanism.

  An annular bore plane 166 provided in a direction substantially perpendicular to the central axis 148 is formed in a counter bore 164 which is a recess formed in the lower portion 162 of the rotor 152, and is the main bearing. An annular thrust surface 128 provided in a direction substantially perpendicular 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 of the main bearing 126 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 hermetic compressor described above shows the basic configuration of the prior art described in Patent Document 1, and has the same configuration as that of the hermetic compressor according to the embodiment of the present invention shown in FIG. is there.

  Therefore, as shown in FIG. 8, the upper race 176 in the prior art described in Patent Document 1 includes a protruding portion 180 in which a part of the inner peripheral portion is a straight line, and the main shaft portion 134 of the shaft 130 is an outer peripheral portion. Is provided with a planar concave portion 182 into which the convex portion 180 of the upper race 176 is fitted (see FIG. 7). The planar convex portion 180 of the upper race 176 and the planar concave portion 182 of the shaft 130 are assembled and assembled to form a stopper 184. The upper race 170 rotates integrally with the shaft 130 by the stopper 184.

  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. Compared to plain bearings, it is smaller and the loss in thrust bearings can be reduced, and the power supplied to the electric elements is reduced, resulting in high efficiency. In addition, the lubricating oil at the bottom of the sealed container is pumped up by the centrifugal force and the inclined oil supply pipe 142 as the shaft 130 rotates, and the lubricating oil is supplied to the thrust surface 128 from the spiral oil supply groove 132 to lubricate the thrust ball bearing 170. .

JP 2012-36905 A

  However, the configuration in which the stopper 184 is provided between the upper race 176 and the shaft 130 disclosed in Patent Document 1 has the following problems. That is, in order to form the planar concave portion 182 on the outer peripheral portion of the shaft 130, the processing for that purpose is a newly added process, which increases the cost. Further, the shaft 130 and the rotor 152 are firmly fastened by means such as press fitting or shrink fitting, and when the planar concave portion 182 exists on the outer periphery of the shaft 130, the concave portion 182 escapes from the strong fastening described above. As a result, the contact area between the outer periphery of the shaft 130 and the inner periphery of the rotor 152 is reduced by the escape, and there is a concern that the fastening force is reduced.

  The present invention solves the above-described problems, and prevents wear caused by sliding at the contact portion between the upper race and the bore plane of the rotor and the inner diameter of the upper race without impairing the fastening force between the shaft and the rotor. An object of the present invention is to provide a highly efficient and highly reliable hermetic compressor that prevents the occurrence of wear at the outer diameter of the shaft and suppresses an increase in power supplied to the electric element.

In order to solve the above problems, the present invention mainly adopts the following configuration.
In the sealed container, an oil storage chamber for storing lubricating oil, an electric element including a stator and a rotor, and a compression element that is driven by the electric element and disposed below the electric element are housed, The compression element includes an eccentric shaft portion and a main shaft portion, a shaft to which the rotor is fastened, a cylinder block having a compression chamber, a piston that reciprocates in the compression chamber, the piston, and the eccentric shaft portion. A coupling mechanism that couples to the cylinder block, a main bearing that pivotally supports the main shaft portion of the shaft, a horizontal plane (bore plane) of the lower recess portion (counter bore) of the rotor, and the main bearing A thrust ball bearing provided between the thrust surface, and the thrust ball bearing includes a plurality of balls, a holder portion for holding the balls, and upper and lower portions of the balls. An upper race and a lower race arranged, and the upper race and a vertical surface (inner peripheral portion of the counter bore) of the lower recess portion (counter bore) of the rotor fastened to the shaft. A stopper is provided between the two to be fitted with each other.

  Further, in the hermetic compressor, the stopper portion includes a protruding portion provided on an outer peripheral portion of the upper race, and a concave portion provided on a vertical surface (an inner peripheral portion of the counter bore) of the lower recess portion of the rotor. , And the convex portion of the upper race and the concave portion of the rotor are fitted. Further, the upper race has the convex portion provided on the outer peripheral portion thereof, and the concave portion provided on the outer peripheral portion opposite to the convex portion passing through the central axis of the upper race, The convex portion and the concave portion have a corresponding opposite shape, and the convex portion and the concave portion are formed simultaneously by die-cutting of a progressive die press using a long steel plate. To do.

  According to the present invention, by providing a stopper between the upper race and the rotor so that the upper race and the shaft rotate integrally, wear prevention due to sliding between the upper race and the bore plane of the rotor is prevented. Further, it is possible to prevent wear due to sliding between the upper race and the shaft. As a result, it is possible to suppress the increase in the power supplied to the electric element and to improve the reliability with high efficiency.

1 is a longitudinal sectional view showing a basic configuration of a hermetic compressor according to an embodiment of the present invention. It is a longitudinal cross-sectional view which shows the principal part of the hermetic compressor which concerns on this embodiment. It is a perspective view which shows the counterbore which is a hollow part formed in the lower part in the rotor regarding this embodiment. It is a perspective view which shows the structure of the upper race of the thrust ball bearing in the sealed compressor which concerns on this embodiment. It is explanatory drawing which shows the die cutting manufacturing process of the upper race of the thrust ball bearing regarding this embodiment. It is a longitudinal cross-sectional view which shows the principal part of the conventional hermetic compressor described in patent document 1. It is a perspective view which shows the detailed structure of the shaft shown in FIG. It is a perspective view of the upper race shown in FIG.

  A hermetic compressor according to an embodiment of the present invention will be described below with reference to FIGS. In FIG. 1, first, a basic configuration of a hermetic compressor according to the present embodiment will be described. In the hermetic container 1, an electric element 2 composed of a stator 52 and a rotor 54 and a compression element 4 that is rotationally driven by the electric element 2 are housed, and lubricating oil 6 is stored at the bottom. . 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.

  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 (see FIG. 2) 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. An oil supply pipe 42 is press-fitted into the lower end 38 of the shaft, and the eccentric shaft portion 36 and the piston 24 are connected by a connecting mechanism 44.

  When the electric element 2 is energized by an external power source, the rotor 54 rotates, and the shaft 30 rotates accordingly, and the rotational movement of the eccentric shaft portion 36 is transmitted to the piston 24 via the coupling mechanism 44. The piston 24 reciprocates in the compression chamber 22, and the compression element 4 performs a predetermined compression operation. By this compression operation, the refrigerant gas is sucked into the compression chamber 22 from the cooling system, compressed, and then discharged to the cooling system again.

  One end of the oil supply pipe 42 communicates with the spiral oil supply groove 32 from the lower end 38 of the eccentric shaft part 36, and the lower end opening 46 of the oil supply pipe 42 is curved on an extension line of the central axis 48 of the main shaft part 34. 6 is open. One end of the oil supply pipe 42 is press-fitted into the lower end 38 of the eccentric shaft portion 36, and the lower end opening 46 is curved on an extension line of the central axis 48 of the main shaft portion 34. The oil 6 is pumped up and each sliding portion is lubricated, and a part thereof is supplied from the spiral oil supply groove 32 to the thrust surface 28 to lubricate the thrust ball bearing 60.

  The electric element 2 is formed of an induction motor, is bolted above the cylinder block 20, and includes a stator 52 provided with a winding 50, and a rotor 54 fixed to the main shaft portion 34 of the shaft 30 by shrink fitting, It is composed of

  An annular bore plane 58 provided substantially at right angles to the central axis 48 is formed in the counter bore 56 that forms a recess (dent) in the lower portion 55 of the rotor 54 laminated with electromagnetic steel plates (FIG. 2). ), An end portion 27 of the main bearing 26 is formed with an annular thrust surface 28 provided substantially at right angles to the central axis 48.

  A thrust ball bearing 60 is disposed between the bore plane 58 in the counter bore 56 and the thrust surface 28 above the main bearing 26 to support the weight of the shaft 30 and the rotor 54. 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 balls 62. The upper race 66 is in contact with the bore plane 58 of the rotor 54, and the lower race 68 is in contact with the thrust surface 28 of the main bearing 26.

  The upper race 66 is provided with a convex portion 80 on the outer peripheral portion, and the inner peripheral portion A of the counter bore (recessed portion) 56 of the rotor 54 has a longitudinal groove shape into which the convex portion 80 of the upper race is fitted. The recess 82 is provided. The convex portion 80 of the upper race 66 and the concave portion 82 of the rotor 54 are assembled and assembled to form a stopper 84. In the illustrated example shown in FIGS. 3 and 4, the projecting portion 80 and the recessed portion 82 have a substantially arc shape in cross section. However, the shape is not limited to this, and the both fitting portions may be in a substantially rectangular shape. Further, a concave portion may be provided in the outer peripheral portion, the upper race 66 may have the same shape as the lower race 68, and a protruding portion that fits in the outer peripheral portion concave portion may be provided in the inner peripheral portion of the counter bore 56.

  FIG. 3 is a perspective view showing the structure of the rotor 54 among the related structures of the rotor 54, the thrust ball bearing 60, and the main bearing 26 shown in FIG. 2 and 3, the inner peripheral portion of the counter bore 56 (recessed portion) is indicated by A, the concave portion 82 provided in the inner peripheral portion A is indicated by B, and is substantially perpendicular to the central axis 48 at the lowermost portion of the rotor 54. The bottom surface provided at is indicated by C. The sketch shown in FIG. 3 is upside down from the cross-sectional view of FIG. 2 for ease of viewing.

  The weight of the shaft 30 and the rotor 54 is supported by a thrust ball bearing 60, and when the shaft 30 rotates, the ball 62 rolls between the upper race 66 and the lower race 68, so that the torque for rotating the shaft 30 is thrust. Smaller than a plain bearing. Therefore, the loss in the thrust bearing can be reduced, the power supplied to the electric element 2 can be reduced, and high efficiency can be achieved.

  Next, by providing a stopper 84 between the upper race 66 and the rotor 54, which is one of the characteristics of the hermetic compressor according to the present embodiment, the sliding between the upper sleeve 66 and the bore plane 58 is achieved. A mechanism for preventing wear due to movement and preventing wear due to sliding between the upper race 66 and the shaft 30 will be described.

  As shown in FIG. 2 and FIG. 4, the convex portion 80 provided on the outer peripheral portion of the upper race 66 and the concave portion 82 provided on the inner peripheral portion of the rotor 54 are fitted. Rotates completely in synchronism with the rotor 54 and the shaft 30, so that the upper race 66 and the bore plane 58 of the shaft 30 and the rotor 54 do not slide and rub, and wear may occur at the contact portion. Absent. Next, the rotor 152 shown in FIG. 3 will be described. The inner periphery of the counter bore 56 of the rotor 54 is provided with a longitudinal groove-like recess 82 into which the upper race protrusion 80 is fitted. The longitudinal groove-shaped recess 82 is formed by punching the recess 82 at the same time in the process of laminating the electromagnetic steel sheets when manufacturing the rotor 54. There is no need to add. That is, in the place where the concave portion 82 is formed in the inner peripheral portion of the counter bore 56 and the portion where the concave portion is not formed, there is no change in the punching of the inner diameter in the same manner. It is not necessary.

  Furthermore, the manufacture of the upper race 66 shown in FIG. 4 will be described with reference to FIG. The upper race 66 is provided with a projecting portion 80 constituting a stopper 84, and the projecting portion 80 is provided with a recessed portion 81 on the opposite side of the outer peripheral portion on an extension line passing through the center of the upper race 66. The reason why the recessed portion 81 is provided is that, in the process of manufacturing the upper race 66, it is generally performed by punching the material of the long steel plate 85 wound around the coil with a progressive die press, The projecting portion 80 and the recessed portion 81 are shaped so as to be simultaneously punched. In contrast to the convex portion 80 of a certain upper race that has been punched out of a long steel plate, a concave portion 81 is produced in the upper race adjacent to the certain upper race. By providing the convex portion 80 on the upper race 66, the size of the outer shape is slightly increased. However, by providing the concave portion 81 corresponding to the convex portion 80, a decrease in the yield of the steel sheet material in the manufacturing process is avoided. (Suppressing offcuts).

  As described above, the hermetic compressor according to the present embodiment has a simple structure, reduces the number of manufacturing processes, suppresses cost increase, and does not impair the fastening force between the shaft and the rotor. By providing a stopper between the upper race and the rotor so that the shaft rotates integrally, it is possible to provide a highly efficient and highly reliable hermetic compressor that suppresses an increase in power supply. Therefore, it can be applied to applications such as vending machines, freezer showcases, and dehumidifiers.

DESCRIPTION OF SYMBOLS 1 Airtight container 2 Electric element 4 Compression element 6 Lubricating oil 20 Cylinder block 22 Compression chamber 24 Piston 26 Main bearing 28 Thrust surface 30 Shaft 34 Main shaft part 36 Eccentric shaft part 44 Connection mechanism 48 Center axis 49 Rotor end ring 52 Stator 54 Rotor 55 Rotor lower part 56 Counter bore (recessed or recessed part of rotor)
58 bore plane 60 thrust ball bearing 62 ball 64 holder portion 66 upper race 68 lower race 80 convex portion 81 concave portion 82 concave portion 84 stop portion 85 long steel plate 176 upper race 178 lower race 180 planar shape convex portion of the upper race 182 Planar concave portion of shaft 184 Stopping portion

Claims (6)

In the sealed container, an oil storage chamber for storing lubricating oil, an electric element including a stator and a rotor, and a compression element that is driven by the electric element and disposed below the electric element are housed,
The compression element includes an eccentric shaft portion and a main shaft portion, a shaft to which the rotor is fastened, a cylinder block having a compression chamber, a piston that reciprocates in the compression chamber, the piston, and the eccentric shaft portion. A coupling mechanism for coupling the shaft, a main bearing fixed to the cylinder block and pivotally supporting the shaft, and a thrust ball bearing provided between a horizontal surface of the lower recess of the rotor and a thrust surface of the main bearing And comprising
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 hermetic compression characterized in that a stopper for fitting the upper race and the rotor is provided between the upper race and the vertical surface of the lower recess of the rotor fastened to the shaft. Machine. In claim 1,
The stopping portion is composed of a protruding portion provided on the outer peripheral portion of the upper race, and a concave portion provided on a vertical surface of the lower recess portion of the rotor,
The hermetic compressor, wherein the convex portion of the upper race and the concave portion of the rotor are fitted. In claim 2,
The upper race has the convex portion provided on the outer peripheral portion thereof, and the concave portion provided on the outer peripheral portion opposite to the convex portion passing through the central axis of the upper race,
The convex portion and the concave portion have correspondingly opposite shapes,
The hermetic compressor is characterized in that the convex portion and the concave portion are formed simultaneously by die-cutting of a progressive die press using a long steel plate. In any one of claims 1 to 3,
The hermetic compressor is characterized in that the fitting stop has a substantially arc shape or a substantially rectangular shape. In claim 1,
The upper race and the lower race have the same shape having a recessed portion on the outer periphery thereof,
A hermetic compressor, wherein a projecting portion that fits into the recessed portion of the outer peripheral portion of the upper race is provided on a vertical surface of the lower recess portion of the rotor.   A refrigerator or an air conditioner in which the hermetic compressor according to any one of claims 1 to 5 is used as a compressor in a refrigeration cycle.

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