JP2014181600A - Sealed compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce such possibility of reducing efficiency due to fine vibration of an upper race and rubbing of a flange part of a shaft and an upper face of the upper race.SOLUTION: A compression element 106 comprises: a shaft having a main shaft part 121 to which a rotator is fixed, an eccentric shaft part 122 and a flange part 123; and a thrust ball bearing 150 arranged between a main bearing 121 and the flange part 123. A pressurizing part 161 is constituted below the flange part 123 of the shaft 120, and a pressure receiving part 162 is provided on the upper race 154. Hardness of the pressurizing part 161 is made not less than 0.7 times larger than hardness of the pressure receiving part 162, and therefore, a loss due to rubbing can be reduced, so as to provide a sealed compressor with good productivity.

Description

  The present invention relates to a hermetic compressor used for a freezer and 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. At the same time, cost reduction is required.

  Conventionally, this type of hermetic compressor employs a thrust ball bearing to improve efficiency (for example, see Patent Document 1).

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

  FIG. 5 is a longitudinal sectional view of a conventional hermetic compressor described in Patent Document 1, and FIG. 6 is a cross-sectional view of a main part of a thrust ball bearing of the conventional hermetic compressor described in Patent Document 1.

  5 and 6, the lubricating oil 2 is stored in the sealed container 1, and the electric element 5 having the stator 3 and the rotor 4 and the compression element 6 driven by the electric element 5 are accommodated. Yes.

  The compression element 6 includes a shaft 12 having a main shaft portion 10 and an eccentric shaft portion 11 to which the rotor 4 is fixed, a cylinder block 14 having a compression chamber 13, a piston 15 reciprocating in the compression chamber 13, A connecting means 16 for connecting the piston 15 and the eccentric shaft portion 11, a main bearing 17 provided on the cylinder block 14 for supporting the main shaft portion 10, and a thrust ball bearing 19 disposed on a thrust surface 18 of the main bearing 17. It has.

  The main bearing 17 includes a thrust surface 18 that is a plane portion substantially perpendicular to the shaft center, and a bearing extension portion 30 that extends further upward than the thrust surface 18 and has an inner surface facing the main shaft portion 10.

  The thrust ball bearing 19 includes a plurality of balls 21 held by a holder portion 20, and an upper race 22 and a lower race 23 disposed above and below the balls 21.

  The upper race 22 and the lower race 23 are annular and metal flat plates, and the upper and lower surfaces are parallel. Further, the holder portion 20 has an annular shape, and a ball 21 is rotatably accommodated in a plurality of holes (not shown) provided in the circumferential direction.

  The support member 29, the lower race 23, the ball 21, and the upper race 22 are stacked in contact with each other in this order on the thrust surface 18, and the flange portion 31 of the shaft 12 is seated on the upper surface of the upper race 22. A predetermined axial gap 32 is provided between the upper end of the shaft 12 and the flange portion 31 of the shaft 12.

  The inner diameter portion 33 of the upper race 22 is brought close to the outer diameter of the main shaft portion 10, and the inner diameter of the upper race 22 is configured to be smaller than the inner diameters of the lower race 23 and the holder portion 20.

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

  When the electric element 5 is energized, the shaft 12 is rotated together with the rotor 4 by the rotating magnetic field generated in the stator 3. The rotational movement of the eccentric shaft portion 11 of the shaft 12 is transmitted to the piston 15 through the connecting means 16, so that the piston 15 reciprocates in the compression chamber 13. Accordingly, the refrigerant gas from the cooling system (not shown) is repeatedly sucked and compressed into the compression chamber 13 and then discharged again to the cooling system.

  When the shaft 12 rotates, the flange portion 31 and the upper race 22 of the shaft 12 are brought into close contact with each other by friction due to a vertical downward thrust load caused by the weight of the rotor 4 and the shaft 12. The ball 21 makes revolution and rotation while being guided by the holder portion 20 by contacting the upper race 22.

JP 2010-255556 A

  However, in the above conventional configuration, when the gap between the inner diameter portion 33 of the upper race 22 and the outer diameter of the main shaft portion 10 is increased, the upper race 22 slightly vibrates, and the flange portion 31 of the shaft 12 and the upper surface of the upper race 22 are By rubbing, loss may occur and efficiency may be reduced.

  The present invention solves the above-described conventional problems, and since the loss can be reduced by reducing the hardness difference between the upper race and the flange portion, the inner race portion between the upper race and the outer diameter of the main shaft portion can be reduced. It is an object of the present invention to provide a hermetic compressor with good productivity.

  In order to solve the above-described conventional problems, the hermetic compressor of the present invention includes a pressing portion under the flange portion of the shaft, the upper race is provided with a pressure receiving portion, and the hardness of the pressing portion is the hardness of the pressure receiving portion. 0.7 times or more.

  As a result, the coefficient of friction between the pressure receiving portion and the pressing portion of the upper race can be kept low, so that the loss due to rubbing is reduced.

  The hermetic compressor of the present invention can provide a high-productivity hermetic compressor because the gap between the inner diameter portion of the upper race and the outer diameter of the main shaft portion can be set large.

1 is a longitudinal sectional view of a hermetic compressor according to Embodiment 1 of the present invention. Sectional drawing of the principal part of the hermetic compressor in the same embodiment Exploded perspective view around the thrust ball bearing in the same embodiment The perspective view of the thin plate in the same embodiment Vertical section of a conventional hermetic compressor Cross section of the main part of a conventional hermetic compressor

According to a first aspect of the present invention, lubricating oil is stored in a sealed container, and an electric element including a stator and a rotor and a compression element driven by the electric element are accommodated, and the compression element is A shaft having a main shaft portion to which a child is fixed, an eccentric shaft portion, and a flange portion, a cylinder block having a compression chamber, a piston that reciprocates in the compression chamber, and the piston and the eccentric shaft portion are coupled to each other. A coupling means; a main bearing provided on the cylinder block for supporting the main shaft portion; and a thrust ball bearing disposed between the main bearing and the flange portion, wherein the thrust ball bearing comprises a holder portion A plurality of balls held on the top and bottom of the ball, and an upper race and a lower race are respectively disposed above and below the ball, and constitute a pressing portion under the flange portion of the shaft, The race includes a pressure receiving portion, the hardness of the pressing portion is obtained by the above 0.7 times the hardness of the pressure receiving portion.

  As a result, the coefficient of friction between the pressure receiving portion and the pressing portion of the upper race can be kept low, so that the loss due to rubbing can be reduced, and between the inner diameter of the upper race and the outer diameter of the main shaft portion. Since the gap can be set large, a hermetic compressor with good productivity can be provided.

  According to a second invention, in the first invention, a thin plate is provided between the flange portion and the pressure receiving portion, the pressing portion is configured on the upper race side of the thin plate, and the thin plate includes a stopper portion, The stopper is attached to the shaft, and the hardness of the thin plate can be easily increased by quenching or the like, so that the productivity can be further improved.

  According to a third invention, in the first invention, the material of the shaft is carbon steel or alloy steel, and the hardness is increased by carburizing or nitriding after reducing the surface roughness of the pressing portion. Therefore, loss due to rubbing can be further reduced and efficiency can be improved.

  According to a fourth invention, in the second invention, the center of gravity of the thin plate does not coincide with the center of the inner diameter hole, and when the shaft rotates, the thin plate is moved toward the center of gravity by centrifugal force, and the inner diameter hole and the outer diameter of the main shaft portion Since the thin plate is stably fixed by the contact portion and the stop portion, the thin plate can be easily assembled and the productivity can be further improved.

  Hereinafter, embodiments of a hermetic compressor according to 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 a first embodiment of the present invention, FIG. 2 is a sectional view of a main part of the hermetic compressor according to the first embodiment, and FIG. 3 is a thrust ball according to the same embodiment. It is a disassembled perspective view of a bearing periphery. FIG. 4 is a perspective view of a thin plate in the same embodiment.

  In FIG. 1 to FIG. 4, lubricating oil 102 is stored in a sealed container 101 and a refrigerant (not shown) is sealed, and is driven by an electric element 105 including a stator 103 and a rotor 104, and the electric element 105. A compression element 106 is received.

  Both the electric element 105 and the compression element 106 are accommodated in a sealed container 101 and supported by a spring 110.

  A terminal 111 fixed to the sealed container 101 supplies electricity (not shown), and supplies electricity to the electric element 105 through the lead wire 112.

  An inverter control circuit 113 is connected to the terminal 111, and a commercial power supply 114 is supplied to the inverter control circuit 113.

  Next, the configuration of the compression element 106 will be described.

  The shaft 120 connects a main shaft portion 121 to which the rotor 104 is fixed, an eccentric shaft portion 122 disposed above the main shaft portion 121 and formed eccentric to the main shaft portion 121, the main shaft portion 121, and the eccentric shaft portion 122. And flange portion 123.

  The cylinder block 130 has a substantially cylindrical compression chamber 131, and a main bearing 132 that supports the main shaft 121 is integrally processed. The piston 133 is inserted into the compression chamber 131 of the cylinder block 130 so as to be slidable back and forth, and is connected to the eccentric shaft portion 122 by a connecting means 134.

  In the vicinity of the upper end of the main bearing 132 of the cylinder block 130, a thrust surface 140 formed in an annular shape substantially perpendicular to the axis of the main bearing 132, and an inner surface that extends further upward than the thrust surface 140 and faces the main shaft portion 121. And a bearing extension 141 having the same.

  The thrust ball bearing 150 is disposed on the thrust surface 140, and a plurality of balls 153 held by the lower race 151 and the holder portion 152 and the upper race 154 are sequentially stacked so that the bearing extension portion 141 is in contact with each other. A predetermined axial gap 155 is provided between the upper end of the upper race 154 and the upper race 154 to constitute an oil supply path to the thrust ball bearing 150. The inner diameter 156 of the upper race 154 is loosely fitted to the outer diameter 157 of the main shaft portion 121 with a gap of 0.1 mm or more.

  A thin plate 160 made of a tool steel plate SK85 material is formed below the flange portion 123 and quenched, and a pressing portion 161 is formed on the upper race 154 side of the thin plate 160, and the upper race 154 formed of bearing steel SUJ2 material receives pressure. The pressure portion 161 has a Vickers hardness of 480, and the pressure receiving portion 162 has a Vickers hardness of 650, which is 0.7 times or more. The thin plate 160 includes a stop portion 163, which is attached to the shaft 120. The thin plate 160 is restricted from moving in the rotation direction by contacting the flange portion 123 of the shaft 120. The center of gravity of the thin plate 160 (symbol A in FIG. 4) is set so as not to coincide with the center of the inner diameter hole 165 (symbol B in FIG. 4).

  As described above, in the present embodiment, in the compressor in which the inside of the hermetic container 101 is a low-pressure type compressor, the bearing that supports the shaft 120 is only one of the main bearings 132 provided below the compression chamber 131. There is a configuration in which the compression chamber 131 is cantilevered in the vertical direction.

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

  The rotor 104 of the electric element 105 rotates the shaft 120, and the rotational movement of the eccentric shaft portion 122 is transmitted to the piston 133 via the connecting means 134, so that the piston 133 reciprocates in the compression chamber 131. Thereby, the refrigerant is sucked into the compression chamber 131 from the cooling system (not shown), compressed, and then discharged to the cooling system again.

  Normally, when the shaft 120 rotates, the flange portion 123 of the shaft 120, the thin plate 160, and the upper surface of the upper race 154 are brought into close contact with each other by friction due to a vertical downward thrust load caused by the weight of the rotor 104 and the shaft 120. Turns and turns.

When the compressor is operated with a pressure difference that greatly fluctuates, the vibrational motion in the radial direction of the shaft 120 with respect to the main bearing 132 increases. For this reason, it is easy to cause radial vibration with the gap between the inner diameter 156 of the upper race 154 and the outer diameter 157 of the main shaft portion 121 as an amplitude, and the pressing portion 161 and the pressure receiving portion 162 of the upper race 154 are rubbed. Since the hardness of the pressing portion 161 is 0.7 times or more that of the pressure receiving portion 162, the friction coefficient between the pressure receiving portion 162 of the upper race 154 and the pressing portion 161 can be kept low, so that the loss due to rubbing Since the gap between the inner diameter 156 of the upper race 154 and the outer diameter 157 of the main shaft portion 121 can be set large, a highly productive hermetic compressor can be provided.

  Furthermore, since the hardness can be easily increased by quenching only the thin plate 160, the productivity can be improved.

  Further, when the shaft 120 rotates, the thin plate 160 is moved toward the center of gravity by centrifugal force, and comes into contact with the inner diameter hole 165 and the outer diameter 157 of the main shaft portion 121 and the thin plate 160 is stably fixed by the stop portion 163. Therefore, productivity can be further improved.

  Although the thin plate 160 is provided between the upper race 154 and the flange portion 123, and the pressing portion 161 is configured on the upper race 154 side of the thin plate 160, the pressing portion 161 is integrally formed under the flange portion 123. Even when the material of the shaft 120 is made of carbon steel or alloy steel, the hardness can be increased by carburizing treatment or nitriding treatment after reducing the surface roughness of the pressing portion 161. Can be further reduced and efficiency can be improved.

  As described above, since the hermetic compressor according to the present invention can increase productivity, the hermetic compressor is also suitable for use as a hermetic compressor of an air conditioner or a vending machine in addition to a refrigerator.

DESCRIPTION OF SYMBOLS 101 Airtight container 102 Lubricating oil 103 Stator 104 Rotor 105 Electric element 106 Compression element 120 Shaft 121 Main shaft part 122 Eccentric shaft part 123 Flange part 130 Cylinder block 131 Compression chamber 132 Main bearing 133 Piston 134 Connecting means 150 Thrust ball bearing 151 Bottom Race 152 Holder portion 153 Ball 154 Upper race 160 Thin plate 161 Pressing portion 162 Pressure receiving portion 163 Stopping portion 165 Inner diameter hole

Claims (4)

The lubricating oil is stored in a sealed container, and an electric element having a stator and a rotor and a compression element driven by the electric element are accommodated, and the compression element is a main shaft on which the rotor is fixed. A shaft having a portion, an eccentric shaft portion, and a flange portion, a cylinder block having a compression chamber, a piston reciprocating in the compression chamber, a connecting means for connecting the piston and the eccentric shaft portion, and the cylinder A main bearing provided on the block and supporting the main shaft portion; and a thrust ball bearing disposed between the main bearing and the flange portion, wherein the thrust ball bearing includes a plurality of holders held by a holder portion. A ball, and an upper race and a lower race are disposed above and below the ball, respectively, and a pressing portion is formed under the flange portion of the shaft. Comprising a part hermetic compressor hardness of the pressing portion is set to more than 0.7 times the hardness of the pressure receiving portion. 2. A thin plate is provided between the flange portion and the pressure receiving portion, the pressing portion is configured on the upper race side of the thin plate, the thin plate includes a stop portion, and the stop portion is attached to the shaft. The hermetic compressor described in 1. The hermetic compressor according to claim 1, wherein a material of the shaft is carbon steel or alloy steel. The hermetic compressor according to claim 2, wherein the thin plate is formed such that the center of gravity of the thin plate does not coincide with the center of the inner diameter hole.

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