JP2012026304A - Hermetic compressor and refrigerating cycle device - Google Patents

Abstract

An object of the present invention is to sufficiently return lubricating oil to a compression chamber even when the operating frequency is low, and to solve the lack of lubrication.
A compression mechanism unit 300 driven by an electric motor unit 220 and a rotating shaft 230 is housed in a sealed container 210, and a refrigerant compressed by the compression mechanism unit 300 is placed outside the sealed container 210. The oil separator 500 is connected to the discharge flow path for direct discharge, and the closed compressor 200 with the suction pressure in the sealed container 210 for supplying the lubricating oil separated by the oil separator 500 to the sliding portion of the compression mechanism unit 300. , The trochoid pump 400 that supplies the oil in the airtight container 210 to the oil separator 500 or the suction side of the compression mechanism unit 300 is provided at the lower end of the rotating shaft 230, and the upper side that forms the pump chamber P of the trochoid pump 400. Lubricating oil having been lubricated between the rotating shaft 230 and the bearing supporting the rotating shaft 230 is supplied to the sliding surface of the pump cover with the rotating shaft 230.
[Selection] Figure 2

Description

  Embodiments described herein relate generally to a hermetic compressor constituting a refrigeration cycle such as an air conditioner and a refrigeration cycle apparatus incorporating the hermetic compressor.

  A closed container low-pressure type compressor that introduces suction gas from the refrigeration cycle into the compression chamber after passing through the sealed container has been developed. In such a hermetic compressor, the lubricating oil is recovered by the oil separator from the refrigerant gas compressed and discharged in the compression chamber, and this recovered lubricating oil is transferred to the bearing portion via the crank chamber of the compression mechanism portion. Refuel. The lubricating oil that has lubricated the bearing portion accumulates in the lower part of the sealed container. This accumulated lubricating oil was returned to the suction side of the compression chamber by the ejector effect of the suction refrigerant sucked into the compression chamber of the compression mechanism.

JP-A-6-280761

  In the above-described hermetic compressor, since the ejector effect is reduced when the operating frequency is low, the amount of lubricating oil that lubricates the bearing portion and accumulates in the lower part of the container from the amount of lubricating oil returned to the suction side of the compression chamber. Will be more. For this reason, the performance as a compressor deteriorates, and there is a possibility that the supply of lubricating oil to the sliding portion is insufficient.

  Therefore, it is necessary to supply sufficient lubricating oil to the sliding portion even when the operation frequency is low.

  An air compressor unit and a compression mechanism unit driven by the motor unit via a rotating shaft are housed in a sealed container, and an oil is supplied to a discharge channel that directly discharges the refrigerant compressed by the compression mechanism unit to the outside of the sealed container. In the hermetic compressor that connects the separator and feeds the lubricating oil separated by the oil separator to the sliding portion of the compression mechanism and uses the suction pressure in the sealed container, the lower end of the rotating shaft is A positive displacement pump that supplies lubricating oil in the closed container to the oil separator or the suction side of the compression mechanism, and the rotary shaft of the upper pump cover that forms a pump chamber of the positive displacement pump. Lubricating oil that has been lubricated between the rotating shaft and the bearing that supports the rotating shaft is supplied to the sliding surface.

The schematic diagram which shows the refrigerating-cycle apparatus incorporating the hermetic type compressor which concerns on 1st Embodiment. The longitudinal cross-sectional view which shows the same hermetic compressor. Explanatory drawing which shows the principal part of the trochoid pump integrated in the same hermetic compressor. The top view which shows the same trochoid pump. The longitudinal cross-sectional view which shows the principal part of the hermetic compressor. Explanatory drawing which shows the relationship between the oil return amount and the operating frequency by the same hermetic compressor. The top view which shows the same trochoid pump. The longitudinal cross-sectional view which shows the principal part of the hermetic compressor.

  1 is a schematic view showing a refrigeration cycle apparatus 100 in which a hermetic compressor 200 according to an embodiment is incorporated, FIG. 2 is a longitudinal sectional view showing a hermetic compressor 200 and an oil separator 500, and FIG. 3 is a trochoid. 4 is a top view showing the trochoid pump 400, FIG. 5 is a longitudinal sectional view showing the main part of the hermetic compressor 200, and FIG. 6 is an oil return by the hermetic compressor 200. It is explanatory drawing which shows the relationship between quantity and an operating frequency.

  The refrigeration cycle apparatus 100 includes a hermetic compressor 200, a four-way valve 101, an outdoor heat exchanger 102 that is a heat source side heat exchanger, an expansion device 103, and an indoor heat exchanger 104 that is a use side heat exchanger. Are communicated in a cycle. 1 and 2, in the refrigeration cycle apparatus 100, the refrigerant discharged from the hermetic compressor 200 passes through the oil separator 500, and during cooling, the solid line passes through the four-way valve 101. As indicated by the arrow, the heat is supplied to the outdoor heat exchanger 102 where it is condensed by exchanging heat with the outside air. The condensed refrigerant flows out of the outdoor heat exchanger 102 and flows to the indoor heat exchanger 104 via the expansion device 103, where it evaporates by exchanging heat with the indoor air and cools the indoor air. The refrigerant that has flowed out of the indoor heat exchanger 104 is sucked into the hermetic compressor 200 through the four-way valve 101 and the suction pipe 212.

  Further, during heating, the refrigerant discharged from the hermetic compressor 200 is supplied to the indoor heat exchanger 104 through the oil separator 500 and through the four-way valve 101 as indicated by a broken line arrow. Heat is exchanged with air to condense and heat indoor air. The condensed refrigerant flows out of the indoor heat exchanger 104 and flows to the outdoor heat exchanger 102 through the expansion device 103, where it evaporates by exchanging heat with outdoor air. The evaporated refrigerant flows out of the outdoor heat exchanger 102 and is sucked into the hermetic compressor 200 through the four-way valve 101 and the suction pipe 212. Thereafter, the refrigerant is sequentially flown in the same manner, and the operation of the refrigeration cycle is continued.

  As shown in FIG. 2, the hermetic compressor 200 includes a hermetically sealed container 210, an electric motor unit 220 accommodated in the hermetic container 210, and a compression mechanism unit 300 coupled to the rotating shaft 230 of the electric motor unit 220. And a trochoid pump positive displacement pump 400 which is a positive displacement pump connected to the lowermost end of the rotating shaft 230.

  An oil reservoir 211 for storing lubricating oil is formed at the lowermost portion of the sealed container 210. In addition, two suction pipes 212 and a discharge pipe 213 are attached to the side surface of the sealed container 210. The two suction pipes 212 are joined to one suction pipe 212A outside the sealed container 210, and a bypass pipe 212B connected to the upper part of the sealed container 210 is branched from the suction pipe 212A. . Thereby, when the hermetic compressor 200 is operated, the pressure in the hermetic container 210 becomes the same suction pressure as the pressure of the refrigerant sucked into the compression mechanism unit 300.

  The compression mechanism unit 300 includes an upper bearing 310 and a lower bearing 320 that rotatably support the rotating shaft 230. Between the upper bearing 310 and the lower bearing 320, an upper cylinder 330, a partition plate 340, and a lower cylinder 350 are arranged from above in FIG. In the compression chambers 331 and 351 provided in the respective cylinders 330 and 350, rollers 332 and 352 rotated by the rotation shaft 230 are arranged.

  An oil supply path 341 is formed in the partition plate 340. One end of the oil supply path 341 is connected to the oil return pipe 510, and the other end is exposed on the outer peripheral surface side of the rotating shaft 230.

  As shown in FIGS. 2 to 5, the trochoid bump 400 houses a rotor 410 having four external teeth 411, a casing 420 formed with five internal teeth 421 a, and the rotor 410 and the casing 420. And an upper pump cover 422 covering the upper surface, and a lower lid plate 430 attached to the lower surface of the upper pump cover 422.

  The rotor 410 includes four external teeth 411 on the circumference, and a mounting hole 412 is formed in the center. A coupler shaft 231 formed at the shaft end of the rotating shaft 230 is fitted into the mounting hole 412.

  The casing 420 is substantially cylindrical, has a hollow portion 421 in which the rotor 410 is accommodated, and the upper surface is covered with the upper pump cover 422. Five inner teeth 421a are formed on the inner wall surface of the hollow portion 421, and five concave grooves 421b are formed between the inner teeth 421a. Further, the upper pump cover 422 is provided with a hole 423 through which the coupler shaft 231 passes. Four oil supply grooves 424 are provided on the upper surface of the upper pump cover 422. The oil supply groove 424 extends from the outer side of the hole 423 toward the outer side in the radial direction, and is provided up to a position corresponding to the outer peripheral surface of the rotating shaft 230.

  A pump chamber P whose volume changes depending on the rotation angle of the rotor 410 is formed between the external teeth 411 of the rotor 410 and the concave groove 421b of the casing 420 described above.

  The lower cover plate 430 is formed with a suction port 431 and a discharge port 432, and communicates with the hollow portion 421 in different regions in the rotation direction. The lower opening of the suction port 431 is immersed in the oil reservoir 211. One end of an oil pipe 433 is connected to the discharge port 432, and the other end of the oil pipe 433 communicates with the suction side (suction passage) of the compression chambers 331 and 351.

  The oil separator 500 separates the refrigerant gas and the lubricating oil, and supplies the lubricating oil to the oil supply path 341 of the partition plate 340 via the oil return pipe 510.

  In the trochoid pump 400 configured as described above, when the rotary shaft 230 is rotationally driven, the rotor 410 is rotationally driven via the coupler shaft 231. As the rotor 410 rotates, the casing 420 rotates through the contact point. With this rotation, the volume of the pump chamber P changes. Since the pump chamber P communicates with the suction port 431 during this stroke, the lubricating oil in the oil reservoir 211 is sucked into the pump chamber P. Next, when passing through the suction port 431, the volume decreases and the lubricating oil is discharged to the discharge port 432, and this lubricating oil is guided to the suction side of the compression chambers 331 and 351.

  The oil separator 500 has a function of separating the lubricating oil from the refrigerant gas compressed by the hermetic compressor 200 and returning it to the hermetic compressor 200.

  The hermetic compressor 200 configured as described above operates as follows. That is, when the electric motor unit 220 is energized, the compression mechanism unit 300 operates.

  As the rotating shaft 230 rotates, the rollers 332 and 352 rotate eccentrically in the compression chambers 331 and 351 to compress the introduced suction gas. Then, the oil is discharged from the discharge pipe 213 and introduced into the oil separator 500. In the oil separator 500, the refrigerant gas and the lubricating oil are separated, and the refrigerant gas goes to the four-way valve 101. Further, the lubricating oil is supplied from the oil return pipe 510 to the oil supply path 341 of the partition plate 340. The lubricating oil supplied to the oil supply path 341 is supplied to the outer peripheral surface of the rotating shaft 230. The lubricating oil flows down along the outer peripheral surface of the rotating shaft 230 and lubricates the sliding surface between the lower bearing 320 and the rotating shaft 230. Further, the lubricating oil flows down and reaches the upper surface of the upper pump cover 422 of the trochoid bump 400. Here, the lubricating oil is supplied to the sliding surface S between the lower end surface of the rotating shaft 230 and the upper surface of the upper pump cover 422 by the oil supply groove 424 and lubricated. Therefore, the sliding surface S between the lower end surface of the rotating shaft 230 and the upper surface of the upper pump cover 422 can be effectively lubricated.

  On the other hand, the lubricating oil in the oil reservoir 211 is sucked into the pump chamber P by the operation of the trochoid pump 400 and discharged by the pump action, and this lubricating oil is guided to the suction side of the compression chambers 331 and 351. . Since the trochoid pump 400 is a positive displacement pump, an amount of lubricating oil proportional to the operating frequency is returned to the suction side of the compression chambers 331 and 351 as shown in FIG. Therefore, even when the operating frequency is low, the lubricating oil can be sufficiently returned to the compression chambers 331 and 351, so that sufficient lubricating oil can be supplied to the sliding portion via the oil separator 500. It becomes possible. It can be seen that the pumping amount is higher when the operating frequency is lower than that using the ejector effect.

  As described above, the hermetic compressor 200 according to the present embodiment pumps up the lubricating oil by the trochoid pump 400 driven by the rotating shaft 230. Therefore, even when the operating frequency is low, the compression chamber 331 is used. , 351 can be sufficiently returned to the lubricating oil.

  FIG. 7 is a top view showing an upper pump cover 422A according to a modification of the trochoid pump 400. FIG. The upper pump cover 422A is provided with an oil supply groove 425 instead of the oil supply groove 424. The oil supply groove 425 has an inner side communicating with the hole 423 and is provided to a position G corresponding to the outer peripheral surface of the rotating shaft 230 toward the radially outer side.

  When configured in this manner, as shown in FIG. 8, the sliding surface between the lower end surface of the rotating shaft 230 and the upper surface of the upper pump cover 422A, as in the case where the oil supply groove 424 is provided. Lubricating oil is supplied to S and lubricated. Furthermore, since the oil supply groove 425 communicates with the hole 423, the lubricating oil is supplied to the sliding portion between the rotor 410 and the casing 420 through the gap between the hole 423 and the coupler shaft 231. . Therefore, the lubrication of the pump chamber P can be performed satisfactorily.

  According to each of these embodiments, the lubricating oil is pumped up by the positive displacement pump, so that the lubricating oil can be sufficiently returned to the compression chamber even when the operation frequency is low, and the lack of lubrication is solved. And a refrigeration cycle apparatus having the hermetic compressor can be provided. In addition, the lubricating oil that has been lubricated between the rotary shaft and the bearing that supports the rotary shaft is supplied to the sliding surface with the rotary shaft of the upper pump cover that forms the pump chamber of the positive displacement pump. The sliding surface can be effectively lubricated.

  In each of the above embodiments, an example in which a trochoid pump is used as a positive displacement pump has been described. However, the present invention is not limited to this, and other positive displacement pumps may be used.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 100 ... Refrigeration cycle apparatus, 200 ... Sealed compressor, 210 ... Sealed container, 220 ... Electric motor part, 230 ... Rotary shaft, coupler shaft 231, 300 ... Compression mechanism part, 310 ... Upper bearing, 320 ... Lower bearing, 330 ... Upper cylinder, 340 ... partition plate, 350 ... lower cylinder, 331, 351 ... compression chamber, 332, 352 ... roller, 340 ... partition plate, 341 ... oil supply path, 400 ... trochoid pump, 410 ... rotor, 411 ... external teeth 412 ... Mounting hole, 420 ... Casing, 421 ... Hollow part, 421a ... Internal tooth, 421b ... Groove, 423 ... Hole part, 424, 425 ... Oil supply groove, 430 ... Lower lid plate, 500 ... Oil separator, 510 ... Oil return pipe.

Claims (3)

An air compressor unit and a compression mechanism unit driven by the motor unit via a rotating shaft are housed in a sealed container, and an oil is supplied to a discharge channel that directly discharges the refrigerant compressed by the compression mechanism unit to the outside of the sealed container. In the hermetic compressor which connects the separator and supplies the lubricating oil separated by the oil separator to the sliding portion of the compression mechanism, and uses the suction pressure in the sealed container.
A positive displacement pump is provided at the lower end of the rotating shaft to supply the lubricating oil in the closed container to the oil separator or the suction side of the compression mechanism,
A lubricating oil having been lubricated between the rotary shaft and a bearing supporting the rotary shaft is supplied to a sliding surface of the upper pump cover forming the pump chamber of the positive displacement pump with the rotary shaft. A hermetic compressor. 2. The hermetic compressor according to claim 1, wherein the lubricating oil supplied to the sliding surface of the upper pump cover with the rotary shaft is further supplied to the pump chamber of the positive displacement pump. A refrigeration cycle apparatus comprising the hermetic compressor according to claim 1, a heat source side heat exchanger, an expansion device, and a use side heat exchanger.

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