JP2006138210A - Hermetic electric compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent abrasion of a slide part occurring when the lubricating state of the slide part is worsened, in an inverter drive type hermetic electric compressor. <P>SOLUTION: In the hermetic electric compressor on which an inverter device 150 is loaded, by disposing a thrust ball bearing 114 on a thrust surface 107a of a bearing part 107 receiving the gravity load of a rotor 104, since a load applied in a thrust direction is all received by the thrust ball bearing 114 even in a state that a lubricating state is worsened, a friction factor in a rotation direction is decreased and friction can be prevented from occurring. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a hermetic electric compressor used in a freezer / refrigerator and the like.

  Conventionally, this type of hermetic electric compressor includes a thrust washer that forms fluid lubrication with oil (see, for example, Patent Document 1).

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

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

  7 and 8, the hermetic container 1 houses an electric element 2 including a stator 3 and a rotor 4 containing a permanent magnet (not shown), and a compression element 5 driven by the electric element 2. In the lower part, oil 6 is stored.

  The compression element 5 includes a cylinder block 9 having a bearing portion 7 and forming a cylinder 8, a crankshaft 10 having an eccentric portion 10a and a main shaft portion 10b, a piston 11 reciprocating in the cylinder 8, and a crankshaft 10 Connecting rod 12 for connecting the eccentric portion 10a and the piston 11 to each other. An oil supply pipe 13 constituting a centrifugal pump is attached to the lower end portion of the eccentric portion 10a of the crankshaft 10.

  Hardened steel thrust washers 14 a and 14 b are sandwiched between the stepped portion 10 c of the crankshaft 10 and the rotor 4, and slide between the thrust surface 7 a formed at the upper end of the bearing portion 7. To do. The bearing portion 7 is made of cast iron or aluminum, and has an oil outflow structure 7b through which oil 6 sucked up from the oil supply pipe 13 flows out on the thrust surface 7a at the upper end.

  The inverter device 50 is connected to the stator 3. The control circuit 51 controls the inverter device 50, and the commercial power supply 52 is connected to the control circuit 51 and the inverter device 50.

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

  The electric power supplied from the commercial power supply 52 is supplied to the electric element 2 via the control circuit 51 and the inverter device 50, and the rotor 4 of the electric element 2 is rotated at an arbitrary rotation speed.

  As the rotor 4 rotates, the crankshaft 10 rotates, and the piston 11 reciprocates in the cylinder 8 via the connecting rod 12 connected to the eccentric portion 10a of the crankshaft 10 to compress the refrigerant gas.

At this time, the oil supply pipe 13 sucks up the oil 6 stored in the sealed container 1 and supplies the oil 6 to the sliding portion, thereby lubricating each sliding portion and flowing out from the oil outflow structure 7b. At this time, the oil 6 flowing out from the oil outflow structure 7 b lubricates the sliding portion formed between the thrust surface 7 a formed at the upper end of the bearing portion 7.
Japanese Patent Laid-Open No. 10-54361

  However, in the conventional configuration described above, the motor equipped with the inverter device 50 is operated at a frequency lower than the commercial power supply frequency, unlike the induction motor. In an operation state at a frequency lower than the commercial power supply frequency, the amount of oil 6 supplied from the oil supply pipe 13 to the sliding portion is reduced, and the lubrication state is deteriorated.

  Further, immediately after the start-up, the oil 6 supplied from the oil supply pipe 13 is still slid by the sliding surface formed by the thrust surface 7a and the thrust washer 14a, or by the main shaft portion 10b of the crankshaft 10 and the bearing portion 7. It has not reached the surface and is not yet supplied to these sliding parts. Therefore, the lubrication of the sliding portion at this time is performed by the remaining adhered oil, and the lubrication state is deteriorated.

  Further, when the inverter device 50 is operated at an extremely low operating frequency such as 25 Hz or less, the hydraulic pressure generated on the sliding surface formed by the thrust surface 7a and the thrust washer 14a is low, and the metal contact is more likely to occur. It becomes.

  When such a state occurs, there is a problem that wear of the thrust surface 7a, the main shaft portion 10b of the crankshaft 10 and the bearing portion 7 easily proceeds.

  The present invention solves the above-described conventional problems, and an object thereof is to provide a highly reliable hermetic electric compressor equipped with an inverter device.

  In order to solve the above-described conventional problems, a hermetic electric compressor according to the present invention includes a thrust ball bearing disposed on a thrust surface of a bearing portion that receives a gravity load of a rotor in an inverter-driven hermetic electric compressor. Thus, even when the lubrication state is deteriorated, all the loads in the thrust direction are received by the ball bearing, so that the friction coefficient in the rotational direction is reduced and wear can be prevented.

  In order to solve the above-described conventional problems, the hermetic electric compressor of the present invention is an inverter-driven hermetic electric compressor in which two or more radial ball bearings are arranged between the crankshaft and the bearing portion. Even when the lubrication state is deteriorated, all the loads in the radial direction are received by the ball bearing, so that the friction coefficient in the rotational direction is reduced, and wear can be prevented.

  In order to solve the above-described conventional problems, the hermetic electric compressor according to the present invention is an inverter-driven hermetic electric compressor in which a solid lubricating coating is applied to the thrust surface of the bearing portion that receives the gravity load of the rotor. The thrust washer is provided, and even when the lubrication state is deteriorated, the friction coefficient is reduced by the self-lubricating action of the solid lubricant coating, and wear can be prevented.

  The hermetic electric compressor of the present invention can improve the reliability of the hermetic electric compressor by improving the sliding state of the sliding portion in the inverter-driven hermetic electric compressor.

  According to the first aspect of the present invention, a compression element that compresses a refrigerant and an electric motor that drives the compression element are housed in an airtight container. Driven at a frequency, the compression element includes a crankshaft that fixes the rotor and a bearing that supports the crankshaft, and a thrust ball bearing is disposed on a thrust surface of the bearing that receives the gravity load of the rotor. In an inverter-driven hermetic electric compressor, when the amount of oil to be supplied decreases during operation at a frequency lower than the commercial power supply frequency, Even if the lubrication condition of the thrust surface deteriorates when oil is not supplied to the moving part, a thrust ball bearing is provided on the thrust surface. Therefore, since all the load related to the thrust is received by the ball bearing, the sliding area in the rotational direction is reduced and the coefficient of friction is reduced, so that it is possible to provide a highly reliable hermetic electric compressor that can prevent the wear of the thrust surface. it can.

  The invention according to claim 2 is the invention according to claim 1, wherein the thrust ball bearing is sandwiched between two or more thrust plates, and the surface roughness is reduced by sandwiching between two or more thrust plates. Ball bearings can also be used for bad thrust parts, and a highly reliable hermetic electric compressor can be provided.

  The invention according to claim 3 is the invention according to claim 2, wherein at least one of the thrust ball bearing and the thrust washer is formed of a nonmagnetic material, and is formed of a nonmagnetic material. Since the material is not magnetized by the rare earth permanent magnet built in the stator of the hermetic electric compressor, it is difficult to attract dust such as iron powder to the thrust surface, and a highly reliable hermetic electric compressor can be provided. At the same time, it is possible to provide a hermetic electric compressor with reduced iron loss and high efficiency.

  According to a fourth aspect of the present invention, a compression element that compresses a refrigerant and an electric motor that drives the compression element are housed in an airtight container. Driven at a frequency, the compression element includes a crankshaft to which the rotor is fixed, a bearing portion that supports the crankshaft, and two or more radial ball bearings are disposed between the crankshaft and the bearing portion. A sealed electric compressor in which the crankshaft is held by the radial ball bearing. In an inverter-driven sealed electric compressor, the amount of oil supplied by operation at a frequency lower than the commercial power supply frequency. Crankshaft and bearing section when there is less or when oil is not supplied to the sliding section Even if the lubrication condition deteriorates, since two or more radial ball bearings are arranged between the crankshaft and the bearing, all the loads in the radial direction are received by the ball bearings, so the friction coefficient in the rotational direction is small. Therefore, it is possible to provide a highly reliable hermetic electric compressor that can prevent wear of the crankshaft and the bearing portion.

  According to a fifth aspect of the present invention, in the invention of the fourth aspect, at least one of the radial ball bearings is formed of a nonmagnetic material, and is formed of a nonmagnetic material so as to be sealed. Since the material is not magnetized by the rare earth permanent magnet built into the stator of the electric compressor, it is difficult to attract iron dust and other dust on the sliding surfaces of the crankshaft and bearings, and a highly reliable sealed electric compressor is It is possible to provide a hermetic electric compressor that can be provided and has high iron loss and high efficiency.

  According to a sixth aspect of the present invention, a compression element that compresses a refrigerant and an electric motor that drives the compression element are housed in an airtight container. Driven at a frequency, the compression element includes a crankshaft that fixes the rotor and a bearing portion that supports the crankshaft, and a solid lubricant coating is applied to a thrust surface of the bearing portion that receives the gravity load of the rotor. This is a hermetic electric compressor with a thrust washer. When the inverter-driven hermetic electric compressor is operated at a frequency lower than the commercial power supply frequency, Immediately after start-up, when the oil is not supplied to the sliding part, even if the lubrication state of the thrust surface deteriorates, the solid lubrication coating on the thrust surface Since disposed a thrust washer subjected to ring, the friction coefficient of the self-lubricating effect of the solid lubricant coating is reduced, it is possible to provide a thrust wear can be prevented with high reliability hermetic electric compressor.

  The invention according to claim 7 is the invention according to any one of claims 1 to 6, wherein a hydrocarbon-based refrigerant not containing chlorine and fluorine is used, and the hydrocarbon-based refrigerant is oil. The amount of oil supplied to the inverter-driven hermetic electric compressor is less than the frequency of the commercial power supply. Even if the lubrication state of the thrust surface and the crankshaft and the bearing portion deteriorates when the amount of oil is reduced or immediately after start-up, the oil is not supplied to the sliding portion, Since all such loads are received by the ball bearings, the sliding area in the rotational direction is reduced, the friction coefficient is reduced, and the radial load is all received by the ball bearings. Since the friction coefficient in the direction is reduced, and the friction coefficient is reduced by the self-lubricating action of the solid lubricant coating, it is possible to prevent wear of the thrust surface, crankshaft, and bearing portion and provide a highly reliable hermetic electric compressor Can do.

  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 side sectional view of a hermetic electric compressor according to Embodiment 1 of the present invention, and FIG. 2 is an enlarged view of a main part of the hermetic electric compressor according to the first embodiment.

  1 and 2, an airtight container 101 houses an electric element 102 including a rotor 103 containing a stator 103 and a permanent magnet (not shown), and a compression element 105 driven by the electric element 102. In the lower part, an oil 106 made of mineral oil is stored. Moreover, the refrigerant | coolant which does not contain chlorine and a fluorine is used for a refrigerant | coolant.

  The compression element 105 includes a bearing block 107 and a cylinder block 109 forming a cylinder 108, a crankshaft 110 having an eccentric portion 110a and a main shaft portion 110b, a piston 111 that reciprocates in the cylinder 108, and a crankshaft 110. The connecting rod 112 for connecting the eccentric portion 110a and the piston 111 is provided. An oil supply pipe 113 constituting a centrifugal pump is attached to the lower end portion of the eccentric portion 110a of the crankshaft 110.

  The bearing portion 107 is made of aluminum, and an upper end thrust surface 107 a is provided with an oil outflow structure 107 b through which oil 106 supplied from an oil supply pipe 113 flows out. A thrust ball bearing is provided between the thrust surface 107 a and the rotor 104. 114 is clamped.

  The thrust ball bearing 114 is provided with a guide plate 117 provided with a plurality of guide holes 116 for freely restraining the thrust ball 115 and above and below the thrust ball 115, and thrust plates 118a and 118b which are in rolling contact with the thrust ball 115, respectively. It is composed of

  Inverter device 150 is connected to stator 103. The control circuit 151 controls the inverter device 150, and the commercial power source 152 is connected to the control circuit 151 and the inverter device 150.

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

  The electric power supplied from the commercial power supply 152 is supplied to the electric element 102 via the control circuit 151 and the inverter device 150, and the rotor 104 of the electric element 102 is rotated at an arbitrary rotation speed.

  As the rotor 104 rotates, the crankshaft 110 rotates, and the piston 111 reciprocates in the cylinder 108 via the connecting rod 112 connected to the eccentric portion 110a of the crankshaft 110 to compress the gas.

  At this time, the oil supply pipe 113 sucks up the oil 106 stored in the sealed container 101 and supplies it to the sliding parts to lubricate each sliding part, and flows out from the oil outflow structure 107b. At this time, the oil 106 flowing out from the oil outflow structure 107b lubricates the thrust surface 107a, the thrust ball bearing 114, and the thrust plates 118a and 118b.

  Here, unlike the induction motor, the electric motor equipped with the inverter device 150 is operated at a frequency lower than the commercial power supply frequency such as 25 Hz or less. In an operation state at a frequency lower than the commercial power supply frequency, the amount of oil 106 supplied from the oil supply pipe 113 to the sliding portion decreases, and the lubrication state deteriorates. Further, at the time immediately after the start, the oil 106 supplied from the oil supply pipe 113 has not yet reached the sliding surface formed by the thrust surface 107a, the thrust ball bearing 114, and the thrust plates 118a and 118b, and enters the sliding portion. Is not yet supplied.

  Therefore, the lubrication of the sliding surface formed by the thrust surface 107a, the thrust ball bearing 141, and the thrust plates 118a and 118b is performed in a state where the amount of oil 106 supplied is small or the remaining adhered oil.

  However, in the thrust ball bearing 114, the thrust ball 115 and the thrust plates 118a and 118b are in rolling contact with each other, so that the friction coefficient in the rotational direction is reduced, and the amount of oil 106 supplied is small or even a small amount of oil is condensed. Wear can be prevented, and wear between the thrust ball 115 and the thrust plates 118a and 118b hardly occurs, and high reliability can be obtained.

  Furthermore, the reduction in the friction coefficient in the rotational direction reduces the sliding loss, resulting in improved efficiency.

  On the other hand, the thrust ball bearing 114 and the thrust plates 118a and 118b are made of a non-magnetic material, for example, ceramics, so that the thrust ball bearing 114 and the thrust plate are made by a permanent magnet (not shown) built in the rotor 104. Since 118a and 118b are not magnetized, dust such as iron powder is not adsorbed and the reliability is further improved.

  In the present embodiment, a hydrocarbon-based refrigerant that does not contain chlorine and fluorine is used as the refrigerant. However, the hydrocarbon-based refrigerant is very compatible with the oil 106 made of mineral oil. The refrigerant gas evaporates from 106 and plugs the oil supply pipe 113 with the refrigerant gas, and the oil supply state to the sliding surface formed by the thrust surface 107a, the thrust ball bearing 114, and the thrust plates 118a and 118b deteriorates. Even in this case, since the thrust ball bearing 114 is in rolling contact with the thrust plate 118a and 118b as described above, the friction coefficient in the rotational direction becomes small, and even a small amount of adhering oil can prevent adhesion. The wear of the thrust ball 115 and the thrust plates 118a and 118b is almost No throat occurs, it is possible to obtain a compressor having high reliability.

(Embodiment 2)
FIG. 3 is a side sectional view of the hermetic electric compressor according to the second embodiment of the present invention, and FIG. 4 is an enlarged sectional view of a main part of the hermetic electric compressor according to the second embodiment.

  3 and 4, the hermetic container 201 houses an electric element 202 including a stator 203 and a rotor 204 containing a permanent magnet (not shown), and a compression element 205 driven by the electric element 202. In the lower part, an oil 206 made of mineral oil is stored. Moreover, the refrigerant | coolant which does not contain chlorine and a fluorine is used for a refrigerant | coolant.

  The compression element 205 includes a cylinder block 209 having a bearing portion 207 and forming a cylinder 208, a crankshaft 210 having an eccentric portion 210a and a main shaft portion 210b, a piston 211 reciprocating in the cylinder 208, and the crankshaft 210 The connecting rod 212 that connects the eccentric portion 210a and the piston 211 is provided. An oil supply pipe 213 constituting a centrifugal pump is attached to the lower end portion of the eccentric portion 210a of the crankshaft 210.

  The bearing portion 207 is made of aluminum, and two radial ball bearings 214a and 214b are press-fitted into the electric element side and the compression element side, respectively, and the thrust load is received by the radial ball bearing 214a press-fitted into the upper side.

  Each of the two radial ball bearings 214a and 214b includes an inner circumferential guide 215a and 215b and a radial ball 217a and 217b that is rotatably held between the outer circumferential guide 216a and 216b.

  The inner diameters of the two radial ball bearings 214 a and 214 b are press-fitted into the main shaft portion 210 b of the crankshaft 210. A lead groove 218 communicating with the oil supply pipe 213 is formed on the outer periphery of the main shaft portion 210b until it reaches the radial ball bearing 214a.

  The inverter device 250 is connected to the stator 203. The control circuit 251 controls the inverter device 250, and the commercial power source 252 is connected to the control circuit 251 and the inverter device 250.

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

  The electric power supplied from the commercial power supply 252 is supplied to the electric element 202 via the control circuit 251 and the inverter device 250, and the rotor 204 of the electric element 202 is rotated at an arbitrary rotation speed.

  As the rotor 204 rotates, the crankshaft 210 rotates, and the piston 211 reciprocates in the cylinder 208 via the connecting rod 212 connected to the eccentric portion 210a of the crankshaft 210 to compress the gas.

  At this time, the oil supply pipe 213 sucks up the oil 206 stored in the sealed container 201 and supplies the oil 206 to the sliding portion, thereby lubricating each sliding portion and flowing out from the oil outflow structure 207b.

  Here, unlike the induction motor, the electric motor equipped with the inverter device 250 is operated at a frequency lower than the commercial power supply frequency such as 25 Hz or less. In an operation state at a frequency lower than the commercial power supply frequency, the amount of oil 206 supplied from the oil supply pipe 213 to the sliding portion is reduced, and the lubrication state is deteriorated. Further, immediately after the start-up, the oil 206 supplied from the oil supply pipe 213 has not yet reached the sliding surface formed by the crankshaft 210 and the bearing portion 207, and has not yet been supplied to the sliding portion.

  Therefore, the lubrication of the crankshaft 210 and the bearing portion 207 is performed in a state where the amount of oil 206 to be supplied is small or the remaining attached oil.

  However, in the radial ball bearings 214a and 214b, the radial balls 217a and 217b are rotatably contacted between the inner peripheral guides 215a and 215b press-fitted with the crankshaft and the outer peripheral guides 216a and 216b press-fitted into the bearing portion 207. As a result, the friction coefficient in the rotational direction is reduced, and even when the amount of oil 206 to be supplied is small or even a small amount of attached oil can be prevented from adhering, the radial balls 217a and 217b, the inner peripheral guides 215a and 215b, and the outer peripheral guide 216a. Wear with 216b hardly occurs, and high reliability can be obtained.

  Furthermore, the reduction in the friction coefficient in the rotational direction reduces the sliding loss, resulting in improved efficiency.

  On the other hand, when the radial ball bearings 214a and 214b are formed of a non-magnetic material such as ceramics, the radial ball bearings 214a and 214b are magnetized by a permanent magnet (not shown) built in the rotor 204. There is no such thing, and dust such as iron powder is not adsorbed and the reliability is further improved.

  In this embodiment, a hydrocarbon-based refrigerant that does not contain chlorine and fluorine is used as the refrigerant. However, the hydrocarbon-based refrigerant is very compatible with the oil 206 made of mineral oil, and as a result, the oil is The refrigerant gas evaporates from 206 and plugs the oil supply pipe 213 with the refrigerant gas, and further, the oil supply state on the sliding surface formed by the crankshaft 210 and the bearing portion 207 is deteriorated. Since the balls 217a, 217b, the inner peripheral guides 215a, 215b and the outer peripheral guides 216a, 216b are in rolling contact with each other, the friction coefficient in the rotational direction is reduced, and even a slight amount of oil can prevent adhesion. 217a, 217b, inner peripheral guides 215a, 215b and outer peripheral guides 216a, 216b hardly wear. , It is possible to obtain high reliability.

(Embodiment 3)
FIG. 5 is a side sectional view of a hermetic electric compressor according to Embodiment 3 of the present invention, and FIG. 6 is an enlarged view of a main part of the hermetic electric compressor according to the same embodiment.

  5 and 6, the hermetic container 301 houses an electric element 302 including a stator 303 and a rotor 304 containing a permanent magnet (not shown), and a compression element 305 driven by the electric element 302. In the lower part, oil 306 made of mineral oil is stored. Moreover, the refrigerant | coolant which does not contain chlorine and a fluorine is used for a refrigerant | coolant.

  The compression element 305 includes a cylinder block 309 having a bearing portion 307 and forming a cylinder 308, a crankshaft 310 having an eccentric portion 310 a and a main shaft portion 310 b, a piston 311 that reciprocates in the cylinder 308, and a crankshaft 310 The eccentric part 310a and the connecting rod 312 for connecting the piston 311 are provided. An oil supply pipe 313 constituting a centrifugal pump is attached to the lower end portion of the eccentric portion 310a of the crankshaft 310.

  The bearing portion 307 is made of aluminum, and has an oil outflow structure 307b through which oil 306 supplied from the oil supply pipe 313 flows out on the thrust surface 307a at the upper end, and a solid lubricating coating is provided between the thrust surface 307a and the rotor 304. Thrust washers 314a and 314b with 314c are sandwiched.

  Inverter device 350 is connected to stator 303. The control circuit 351 controls the inverter device 350, and the commercial power source 352 is connected to the control circuit 351 and the inverter device 350.

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

  The electric power supplied from the commercial power source 352 is supplied to the electric element 302 via the control circuit 351 and the inverter device 350, and the rotor 304 of the electric element 302 is rotated at an arbitrary rotation number.

  As the rotor 304 rotates, the crankshaft 310 rotates, and the piston 311 reciprocates in the cylinder 308 via the connecting rod 312 connected to the eccentric portion 310a of the crankshaft 310 to compress the gas.

  At this time, the oil supply pipe 313 sucks up the oil 306 stored in the sealed container 301 and supplies the oil 306 to the sliding parts to lubricate each sliding part, and flows out from the oil outflow structure 307b. At this time, the oil 306 flowing out from the oil outflow structure 307b lubricates the thrust surface 307a and the thrust washers 314a and 314b.

  Here, unlike the induction motor, the electric motor equipped with the inverter device 250 is operated at a frequency lower than the commercial power supply frequency such as 25 Hz or less. In an operation state at a frequency lower than the commercial power supply frequency, the amount of oil 306 supplied from the oil supply pipe 313 to the sliding portion is reduced, and the lubrication state is deteriorated. Further, immediately after the start-up, the oil 306 supplied from the oil supply pipe 313 has not yet reached the sliding surface formed by the thrust surface 307a and the thrust washers 314a and 314b, and has not yet been supplied to the sliding portion.

  Therefore, the lubrication of the sliding surface formed by the thrust surface 307a and the thrust washers 314a and 314b is performed in a state where the amount of oil 306 supplied is small or the remaining adhered oil.

  However, since the thrust washers 314a and 314b are provided with the solid lubricant coating 314c, the friction coefficient in the rotational direction is reduced, and adhesion can be prevented even when the amount of oil 306 supplied is small or even a small amount of oil is attached. Further, wear between the thrust surface 307a and the thrust washers 314a and 314b hardly occurs, and high reliability can be obtained.

  Furthermore, the reduction in the friction coefficient in the rotational direction reduces the sliding loss, resulting in improved efficiency.

  In this embodiment, a hydrocarbon-based refrigerant that does not contain chlorine and fluorine is used as the refrigerant. However, the hydrocarbon-based refrigerant is very compatible with the oil 306 made of mineral oil, and as a result, the oil is The refrigerant gas evaporates from 306 and plugs the oil supply pipe 313 with the refrigerant gas, and the oil supply state to the sliding surface formed by the thrust surface 307a and the thrust washers 314a and 314b deteriorates. Since the solid lubricant coating 314c is applied to the thrust washers 314a and 314b, the friction coefficient in the rotational direction is reduced, and even a slight amount of adhering oil can prevent adhesion, so the thrust surface 307a and the thrust washers 314a and 314b Wear hardly occurs, and a compressor with high reliability can be obtained.

  Although the solid lubricant coating 314c is applied to the thrust washers 314a and 314b, wear is similarly prevented even if shot dining of molybdenum disulfide or using tetrafluoroethylene as the material of the thrust washers 314a and 314b. An effect is obtained.

  As described above, the inverter-driven hermetic electric compressor according to the present invention can be self-lubricated even when the lubrication state of the sliding portion is deteriorated. Therefore, in addition to the refrigeration system, the air conditioner and the vending machine are used. It can also be applied to.

Side sectional view of hermetic electric compressor according to Embodiment 1 of the present invention. The principal part enlarged view of the hermetic type electric compressor in Embodiment 1 of this invention Side sectional view of a hermetic electric compressor according to Embodiment 2 of the present invention. The principal part expanded sectional view of the hermetic type electric compressor in Embodiment 2 of the present invention. Side sectional view of a hermetic electric compressor according to Embodiment 3 of the present invention. The principal part enlarged view of the hermetic type electric compressor in Embodiment 3 of this invention Side sectional view of a conventional hermetic electric compressor Enlarged view of the main parts of a conventional hermetic electric compressor

Explanation of symbols

101, 201, 301 Sealed container 102, 202, 302 Electric element 103, 203, 303 Stator 104, 204, 304 Rotor 105, 205, 305 Compression element 107, 207, 307 Bearing part 107a, 307a Thrust surface 110, 210 , 310 Crankshaft 114 Thrust ball bearing 118a, 118b Thrust plate 150, 250, 350 Inverter device 214a, 214b Radial ball bearing 314a, 314b Thrust washer 314c Solid lubricant coating

Claims (7)

  A compression element that compresses the refrigerant and an electric element that drives the compression element are housed in an airtight container. The electric element includes a stator and a rotor, and is driven at two or more specific frequencies by an inverter device. The element is a hermetic electric compressor including a crankshaft to which the rotor is fixed and a bearing portion that supports the crankshaft, and a thrust ball bearing is disposed on a thrust surface of the bearing portion that receives the gravity load of the rotor.   The hermetic electric compressor according to claim 1, wherein the thrust ball bearing is sandwiched between two or more thrust plates.   The hermetic electric compressor according to claim 2, wherein at least one of the thrust ball bearing or the thrust washer is formed of a non-magnetic material.   A compression element that compresses the refrigerant and an electric element that drives the compression element are housed in an airtight container. The electric element includes a stator and a rotor, and is driven at two or more specific frequencies by an inverter device. The element includes a crankshaft to which the rotor is fixed, and a bearing portion that supports the crankshaft, and two or more radial ball bearings are disposed between the crankshaft and the bearing portion, and the radial ball bearing is used as the element. A hermetic electric compressor holding a crankshaft.   The hermetic electric compressor according to claim 4, wherein at least one of the radial ball bearings is formed of a non-magnetic material.   A compression element that compresses the refrigerant and an electric element that drives the compression element are housed in an airtight container. The electric element includes a stator and a rotor, and is driven at two or more specific frequencies by an inverter device. The element includes a crankshaft to which the rotor is fixed, a bearing portion that supports the crankshaft, and a thrust washer that is provided with a solid lubricant coating on the thrust surface of the bearing portion that receives the gravity load of the rotor. Type electric compressor.   The hermetic electric compressor according to any one of claims 1 to 6, wherein a hydrocarbon-based refrigerant containing no chlorine and fluorine is used.

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