JP4806552B2 - Hermetic compressor and refrigeration cycle apparatus - Google Patents

Description

  The present invention relates to a rotary-type hermetic compressor including a plurality of compression mechanisms and a refrigeration cycle apparatus that is a refrigerating cycle using the hermetic compressor, for example, an air conditioner.

In recent years, a two-cylinder rotary hermetic compressor including two sets of cylinders constituting a compression mechanism is being standardized. This type of compressor includes a cylinder chamber that always performs a compression action and a cylinder chamber that can be switched between a compression operation and a non-compression operation (cylinder operation) that is stopped according to the magnitude of the load. If possible, the specifications will be expanded and advantageous.
In view of this, the applicant of the present invention disclosed in [Patent Document 1] a hermetic compressor provided with two cylinder chambers and switching means for stopping the compression action in one cylinder chamber or performing the compression action as necessary. And it came to provide the refrigerating-cycle apparatus which is a refrigerating-cycle circuit provided with this compressor, for example which is an air conditioner.
Specifically, a vane (blade) provided in one of the cylinder chambers is pressed and urged by a spring member so as to always perform a compression action. In the other cylinder chamber, the vane chamber for storing the vane is exposed in the sealed case and exposed to the pressure in the case (high-pressure atmosphere). Then, a high pressure or a low pressure is introduced to the other cylinder chamber, a differential pressure is generated between the leading end and the trailing end of the vane, or switching is performed so that no differential pressure is generated, and the vane is pressed and urged to contact the roller. Alternatively, it is separated from the roller.
JP 2004-301114 A

By adopting such a configuration, the pressure biasing structure for the vanes can be simplified, and the change from the large capacity operation to the low capacity operation can be facilitated. However, on the other hand, a pressure switching device such as an open / close valve is required in the refrigerant suction passage communicating with the cylinder chamber. As a result, resistance is generated in the suction passage, which may lead to a decrease in compression performance.
Moreover, the technique of the above-mentioned [Patent Document 1] is a so-called high pressure type in the case in which the high pressure gas compressed by the compression mechanism unit is once discharged into the sealed case and then filled out and then led out of the sealed case. Intended for compressors. The vane chamber on the pressure switching side is exposed to the case internal pressure (high pressure atmosphere).
On the other hand, in-case low pressure type hermetic compressors are often used. That is, the refrigerant gas whose pressure has been reduced in the refrigeration cycle is guided into the sealed case and filled. The inside of the sealed case and each cylinder chamber communicate directly with each other through a suction pipe, and the low-pressure gas in the sealed case is sucked into each cylinder chamber from the suction pipe and compressed. The above [Patent Document 1] makes no mention of this type of in-case low pressure type hermetic compressor.

  The present invention has been made on the basis of the above circumstances, and the object thereof is a low pressure type in the case, and the rear end side of the vane in a specific compression mechanism portion is set to a low pressure or a high pressure so that a large capacity operation and a low capacity are achieved. It is an object of the present invention to provide a hermetic compressor that can reliably switch to operation and a refrigeration cycle apparatus that includes this hermetic compressor and obtains improved refrigeration cycle performance.

In order to satisfy the above object, the hermetic compressor of the present invention accommodates the motor unit and a plurality of compression mechanism units in a sealed case via a rotating shaft, and the sealed case has a low pressure atmosphere.
The inside of the sealed case has a low pressure atmosphere,
The refrigerant compressed by the plurality of compression mechanisms is discharged through an oil separator provided outside the sealed case,
The plurality of compression mechanisms are each provided with a cylinder chamber in which a roller is housed so as to be eccentrically rotatable, and the rotation direction of the roller is urged so that the tip is in contact with the circumferential surface of the roller. The vane that bisects the cylinder chamber along the line, and the rear end of the vane and the bottom of the oil separator communicate with each other, and the high pressure lubricating oil in the oil separator is guided from the bottom of the oil separator to the rear end of the vane. Has an introduction passage,
At least one compression mechanism portion in the plurality of compression mechanism portions has a pressure switching mechanism that controls communication of the high pressure introduction passage and switches the rear end side of the vane to low pressure or high pressure,
A high-capacity operation in which a compression switching operation is performed with all the compression mechanism sections using a pressure switching mechanism according to the size of the load, with the rear end side of the vane in a specific compression mechanism section being a high pressure, and the vane is removed from the roller by switching to a low pressure. It was possible to switch to low-capacity operation that was separated and not compressed.
In order to satisfy the above object, a refrigeration cycle apparatus of the present invention includes the above-described hermetic compressor, a condenser, an expansion device, and an evaporator to constitute a refrigeration cycle circuit.

According to the hermetic compressor of the present invention, it is a low pressure type in the case, and the operation can be reliably switched according to the magnitude of the load, and the effect of improving the compression efficiency can be obtained.
And according to the refrigerating-cycle apparatus which comprises a refrigerating-cycle circuit using the hermetic compressor of this invention, there exists an effect which can obtain the improvement of refrigerating efficiency.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a configuration diagram of a sectional structure of a rotary type hermetic compressor R and a refrigeration cycle circuit K of a refrigeration cycle apparatus including the hermetic compressor R.
First, the hermetic compressor R will be described. 1 is a hermetic case, and a lower part in the hermetic case 1 is provided with a first compression mechanism part 2A and a second compression mechanism part 2B, which will be described later. Is provided with an electric motor section 3. The electric motor unit 3 and the first and second compression mechanism units 2A and 2B are connected via the rotating shaft 4 and are integrally accommodated in the sealed case 1.

The electric motor unit 3 includes a stator 5 that is fitted and fixed to the inner peripheral wall of the hermetic case 1, and a rotor 6 that is disposed inside the stator 5 with a predetermined gap and is fitted to the rotating shaft 4. Consists of
The first and second compression mechanism portions 2A and 2B are respectively disposed above and below the rotating shaft 4 via an intermediate partition plate 7, and each of the first and second compression mechanism portions 2A and 2B includes a first cylinder 8A and a second cylinder 8B. I have. The first and second cylinders 8A and 8B are formed to have the same outer shape and inner diameter, and the outer peripheral surfaces of the cylinders 8A and 8B are fitted and fixed to the inner peripheral wall of the hermetic case 1. There is no.

  A main bearing 9 composed of a flange portion 9a and a boss portion 9b is superimposed on the upper surface portion of the first cylinder 8A. The main bearing flange portion 9a is placed on the first cylinder 8A, and the main valve cover B1 is overlaid on the flange portion 9a, and is fixedly attached to the first cylinder 8A via the mounting bolts a. A sub bearing 10 composed of a flange portion 10a and a boss portion 10b is overlaid on the lower surface portion of the second cylinder 8B. The sub-valve cover B2 is overlaid on the lower surface of the flange portion 9a of the sub-bearing 10, and is attached and fixed to the first cylinder 8A via mounting bolts b.

  A seal structure is employed for the mating surface of the main valve cover B1 and the main bearing flange portion 9a and the through portion of the main bearing boss portion 9b with respect to the main valve cover B1. A seal structure is also adopted for the mating surface of the sub valve cover B2 and the sub bearing flange portion 10a and the through portion of the sub bearing boss portion 10b with respect to the sub valve cover B2. Furthermore, it goes without saying that sealing structures are also employed for the mating surfaces of the main bearing 9, the first cylinder 8A, the intermediate partition plate 7, the second cylinder 8B, and the auxiliary bearing 10, respectively.

The upper surface and the lower surface of the first cylinder 8A are partitioned by the main bearing 9 and the intermediate partition plate 7, and a first cylinder chamber 12a is formed in the inner diameter portion. The second cylinder 8B is divided into an upper surface and a lower surface by the auxiliary bearing 10 and the intermediate partition plate 7, and a second cylinder chamber 12b is formed in the inner diameter portion.
Each of the cylinders 8A and 8B is provided with suction holes 13a and 13b extending from the outer peripheral surface to the inner diameter portion, and one end of each of the suction holes 13a and 13b is connected to the first cylinder chamber 12a formed in each cylinder 8A and 8B and the first cylinder chamber 12a. Communicates with the second cylinder chamber 12b. The end of each suction hole 13a, 13b that opens to the outer peripheral surface of the cylinder 8A, 8B is connected to the end of a suction pipe S provided through the sealed case 1. Each suction pipe S merges with the outside of the sealed case 1, the end of this combined suction pipe S is connected to the upper part of the sealed case 1, and the open end faces the sealed case 1.

  On the other hand, the flange portion 9a of the main bearing 9 is provided with a first discharge valve mechanism Ta covered with the main valve cover B1. Further, the flange portion 10a of the auxiliary bearing 10 is also provided with a second discharge valve mechanism Tb covered with the auxiliary valve cover B2. Each discharge valve mechanism Ta, Tb is provided with a recess in the main and auxiliary bearing flange portions 9a, 10a, and a discharge port is provided in a thin portion left between the recess and the cylinder chamber facing surface of the flange portion. A discharge valve is attached to the recess, and the discharge valve opens and closes the discharge port.

Therefore, the first discharge valve mechanism Ta communicates with the first cylinder chamber 12a, and the second discharge valve mechanism Tb communicates with the second cylinder chamber 12b. As will be described later, a refrigerant pipe P is connected to the main valve cover B1 covering the first discharge valve mechanism Ta, and no piping is connected to the sub valve cover B2 covering the second discharge valve mechanism Tb.
However, although not shown in particular, it extends from the auxiliary bearing flange portion 10a covered by the auxiliary valve cover B2 to the second cylinder 8B, the intermediate partition plate 7, the first cylinder 8A and the main bearing flange portion 9a. A gas guide hole is provided, and the inside of the main valve cover B1 communicates with the sub valve cover B2.

  The rotating shaft 4 is pivotally supported at the midway portion and the lower end portion thereof on the boss portions 9b and 10b of the main bearing 9 and the sub bearing 10, respectively. Further, the rotary shaft 4 penetrates through the inner diameter portions of the cylinders 8A and 8B, and integrally includes two eccentric portions 4a and 4b formed with a phase difference of about 180 °. Each eccentric part 4a, 4b makes the same diameter mutually, and is assembled so that it may be located in each cylinder chamber 12a, 12b. Eccentric rollers 14a and 14b having the same diameter are fitted on the peripheral surfaces of the eccentric portions 4a and 4b.

The eccentric roller 14a is accommodated in the first cylinder chamber 12a so as to be eccentrically rotatable, and a part of the circumferential surface along the axial direction is in rolling contact with the circumferential surface of the cylinder chamber 12a (that is, line contact). As the eccentric roller 14a rotates eccentrically in the cylinder chamber 12a, the rolling contact position of the eccentric roller 14a with respect to the cylinder chamber 12a gradually changes along the circumferential surface of the cylinder chamber 12a.
The eccentric roller 14b is also accommodated in the second cylinder chamber 12b so as to be eccentrically rotatable, and a part of the circumferential surface along the axial direction is in rolling contact (line contact) with the circumferential surface of the cylinder chamber 12b. Therefore, when the eccentric roller 14b rotates eccentrically in the cylinder chamber 12b, the rolling contact position of the eccentric roller 14b with respect to the cylinder chamber 12b gradually changes along the circumferential surface of the cylinder chamber 12b.

  The first and second cylinder chambers 12a and 12b are formed to have the same diameter and height, and the height of each eccentric roller 14a and 14b is the same as the height of the first and second cylinder chambers 12a and 12b. Are formed substantially the same. Accordingly, the eccentric rollers 14a and 14b have a phase difference of 180 ° from each other, but are set to the same excluded volume in the first and second cylinder chambers 12a and 12b by rotating eccentrically.

  The first cylinder 8A and the second cylinder 8B are provided with vane chambers 15a and 15b communicating with the first and second cylinder chambers 12a and 12b. The vane chamber 15a provided in the first cylinder 8A is closed by the main bearing flange portion 9a and the intermediate partition plate 7, and the vane chamber 15b provided in the second cylinder 8B is provided by the intermediate partition plate 7 and the auxiliary bearing flange portion 10a. It is blocked by. That is, each vane chamber 15a, 15b is a sealed space.

  The vanes 16a and 16b are slidably accommodated in the respective vane chambers 15a and 15b. The tips of the vanes 16a and 16b can protrude and retract with respect to the first and second cylinder chambers 12a and 12b. In particular, a spring member 17 is accommodated in a vane chamber 15a provided in the first cylinder 8A. The spring member 17 is interposed between the rear end of the vane 16a and the back surface of the vane chamber 15a, and applies an elastic force (back pressure) to the vane 16a to elastically contact the tip of the vane 16a with the circumferential surface of the eccentric roller 14a. It is a compression spring.

  While the vane 16b accommodated in the vane chamber 15b on the second cylinder 8B side is formed of a magnetic material, the rear end side that contacts the inner peripheral wall of the sealed case 1 of the vane chamber 15b (that is, the rear of the vane 16b). A holding member 18 made of a permanent magnet is attached to the end side. If the rear end of the vane 16b comes into contact with the holding member 18 under the condition that no high pressure is applied to the vane chamber 15b, the holding member 18 can magnetically attract the vane 16b to fix and hold the position of the vane 16b.

The tips of the vanes 16a and 16b are each formed in a semicircular shape in a plan view, and when pressed and biased as described later, the tips are axial directions of circular eccentric rollers 14a and 14b in a plan view. Can be brought into line contact regardless of the rotation angle of the eccentric rollers 14a, 14b.
An oil reservoir 19 is formed on the inner bottom of the sealed case 1 to store lubricating oil. The first compression mechanism portion 2A, the second compression mechanism portion 2B, and the intermediate partition plate 7 are provided with oil guide holes (not shown) penetrating in the upper and lower surfaces. It is in an immersion state. The lower end surface of the rotating shaft 4 is exposed from the auxiliary bearing boss 10b and is exposed to the lubricating oil. Although not shown, an oil supply passage is provided from the lower end surface of the rotating shaft 4, and oil is supplied to the sliding contact portions of the compression mechanism portions 2 </ b> A and 2 </ b> B as the rotating shaft 4 rotates.

The hermetic compressor R is incorporated in a refrigeration cycle circuit K constituting a refrigeration cycle apparatus. That is, as described above, the refrigerant pipe P connected to the main valve cover B1 extends from the bottom of the oil separator 20 that extends through the sealed case 1 to the outside and is integrally attached to the side of the sealed case 1. Inserted inside.
The oil separator 20 is provided with a plurality of perforated plates 21 provided in parallel with a large number of holes c at predetermined intervals. The upper end of the refrigerant pipe P is attached so as to open at a lower portion of the lowermost porous plate 21. The perforated plate 21 is attached so that the positions of the holes c do not oppose each other and are shifted from each other, and the gas flowing through the holes c of the lower side porous plate 21 always collides with the plate surface of the upper side porous plate 21, and then A so-called baffle plate that circulates the hole c is formed.

A refrigerant pipe P is also connected to the upper end of the oil separator 20. The refrigerant pipe P is sequentially provided with a condenser 22, an expansion mechanism (expansion device) 23, and an evaporator 24. The refrigerant pipe P is connected from the evaporator 24 to the upper end portion of the hermetic case 1 of the hermetic compressor R, and the open end portion faces the inside of the hermetic case 1.
A pressure switching mechanism 25 is provided across the refrigeration cycle circuit K configured in this manner and the hermetic compressor R. The pressure switching mechanism 25 includes a high-pressure introduction pipe (high-pressure introduction passage) 26 and an electromagnetic opening / closing valve 27 provided at a predetermined portion of the high-pressure introduction pipe 26.

  In other words, one end of the high-pressure introduction pipe 26 is connected to the bottom of the oil separator 20, and the lubricating oil separated from the high-pressure gas by the high-pressure gas in the oil separator 20 or the perforated plate 21 in the oil separator 20. Can be led. The high pressure introduction pipe 26 is branched into two outside the oil separator 20, and the first branch high pressure introduction pipe 26a penetrates the sealed case 1 and communicates with the vane chamber 15a from the outer peripheral surface of the first cylinder 8A. As described above, the spring member 17 that elastically presses and biases the vane 16a of the first cylinder chamber 12a is provided in the vane chamber 15a, and the opening end of the first branch high-pressure introduction pipe 26a is a spring. It opens facing the member 17.

  Further, the electromagnetic branch valve 27 is provided in the second branch high-pressure introduction pipe 26b, and this end portion is connected so as to penetrate the sealed case 1 and communicate with the vane chamber 15b from the outer peripheral surface of the second cylinder 8B. . As described above, the holding member 18 is provided at the end of the second cylinder 8B forming the vane chamber 15b, and the opening end of the second branch high-pressure introduction pipe 26b extends along the radial direction of the holding member 18. It opens to the guide hole part d penetrating through.

  Due to the configuration of the pressure switching mechanism 25 described above, the separated lubricating oil (some of which may contain high-pressure gas) in the oil separator 20 is guided to the high-pressure introduction pipe 26, and the first branch high-pressure introduction pipe 26a. To the vane chamber 15a provided in the first cylinder 8A. Further, if the electromagnetic on-off valve 27 provided in the second branch high-pressure introduction pipe 26b is opened, the lubricating oil in the oil separator 20 is supplied from the branch high-pressure introduction pipe 26b to the vane chamber 15b provided in the second cylinder 8B. To be introduced. If the electromagnetic on-off valve 27 is closed, the flow is cut off and is not led to the vane chamber 15b.

Next, the operation of the refrigeration cycle apparatus provided with the above-described hermetic compressor R will be described. As will be described later, the hermetic compressor R can be switched between a large capacity operation (twin operation) and a low capacity operation (single operation) by switching the pressure switching mechanism 25.
First, the high-capacity operation will be described. The control unit sends an operation start signal to the motor unit 3 and sends an open signal to the electromagnetic on-off valve 27 of the pressure switching mechanism 25. The rotary shaft 4 is rotationally driven, and the first compression mechanism 2A and the second compression mechanism 2B act simultaneously. The eccentric rollers 14a and 14b rotate eccentrically in the first and second cylinder chambers 12a and 12b, respectively.

  In the first compression mechanism portion 2A, the vane 16a is always elastically pressed and biased by the spring member 17, and the tip of the vane 16a is in sliding contact with the circumferential surface of the eccentric roller 14a to compress the inside of the first cylinder chamber 12a with the suction chamber. Divide into rooms. The first cylinder chamber 12a has a maximum space capacity in a state in which the inner circumferential surface rolling contact position of the eccentric roller 14a coincides with the vane 16a tip position, and the vane 16a is retracted most.

The low-pressure refrigerant gas filled in the sealed case 1 is sucked into the first cylinder chamber 12a and the second cylinder chamber 12b through the suction pipe S. In the first cylinder chamber 12a, as the eccentric roller 14a rotates eccentrically, the rolling contact position of the eccentric roller 14a with respect to the inner peripheral surface of the cylinder chamber 12a moves, and the volume of the compression chamber partitioned by the vane 16a decreases. That is, the gas previously introduced into the cylinder chamber 12a is gradually compressed.
The rotary shaft 4 continues to rotate, the capacity of the compression chamber in the first cylinder chamber 12a further decreases, the refrigerant gas is compressed, and the first discharge valve mechanism Ta operates when the refrigerant gas rises to a predetermined pressure. The refrigerant gas compressed in the first cylinder chamber 12a and having a high pressure is discharged into the main valve cover B1 and further led to the oil separator 20 through the refrigerant pipe P.

In the oil separator 20, the high-pressure refrigerant gas flows through a large number of holes c formed in the plurality of perforated plates 21 to separate the lubricating oil contained in the refrigerant gas, and only the pure gas is oil. It is led from the separator 20 to the condenser 22. The high-pressure refrigerant is condensed and liquefied by the condenser 22, is adiabatically expanded by the expansion mechanism 23, and takes the latent heat of evaporation from the heat exchange air by the evaporator 24 to perform a cooling (refrigeration) action.
Then, the refrigerant gas evaporated and reduced in pressure by the evaporator 24 is guided and filled in the sealed case 1, and again from the suction pipe S, the first and second compression mechanism portions 2A and 2B are supplied with the first and second refrigerant gases. Sucked into the cylinder chambers 12a and 12b.

Note that the high-pressure refrigerant gas compressed by the hermetic compressor R and guided to the oil separator 20 is separated here, and lubricating oil accumulates in the inner bottom portion. The high-pressure lubricating oil is guided from the high-pressure introduction pipe 26 to the vane chamber 15a provided in the first cylinder 8A through the first branch high-pressure introduction pipe 26a. As described above, since the vane chamber 15a is a sealed space, the high-pressure lubricant is filled in the vane chamber 15a to increase the pressure.
Although the spring member 17 is provided in the vane chamber 15a and an elastic force is applied to the rear end of the vane 16a, the high-pressure lubricating oil is filled and a higher back pressure is applied to the rear end of the vane 16a. The tip of the vane 16a reliably contacts the circumferential surface of the roller 14a that rotates eccentrically, and bisects the first cylinder chamber 12a in a constantly stable state.

The high-pressure lubricating oil introduced from the oil separator 20 to the second branch high-pressure introduction pipe 26b through the high-pressure introduction pipe 26 is a vane chamber provided in the second cylinder 8B from the position where the electromagnetic on-off valve 27 is opened. It fills 15b. Since the vane chamber 15b is also a sealed space, the pressure is increased by high-pressure lubricating oil, and a high back pressure is applied to the rear end of the vane 16b.
As described above, the low-pressure refrigerant is introduced into the second cylinder chamber 12b from the suction pipe S to form a low-pressure atmosphere, while the vane chamber 15b is increased in pressure by the high-pressure lubricant. Therefore, the tip of the vane 16b provided in the second cylinder chamber 12b has a low pressure atmosphere, the rear end has a high pressure atmosphere, and differential pressure is generated at both ends. Under the influence of this differential pressure, the tip of the vane 16b is pressed and urged so as to be in sliding contact with the circumferential surface of the eccentric roller 14b. The vane 16b reliably contacts the circumferential surface of the eccentric rotating roller 14b and bisects the cylinder chamber 12b in a constantly stable state.

Note that the holding member 18 exerts a magnetic force so as to magnetically attract the rear end of the vane 16b, but the magnetic force is based on a differential pressure between the suction pressure of the second cylinder chamber 12b and the pressure of the vane chamber 15b. Is also small. Therefore, there is no influence of the holding member 18 on the vane 16b.
The same compression action is performed in the second cylinder chamber 12b as the vane 16a on the first cylinder chamber 12a side is pressed and urged by the spring member 17 and the compression action is performed. Eventually, in the hermetic compressor R, a large capacity operation is performed in which the compression action is performed by both the first compression mechanism 2A and the second compression mechanism 2B.

Next, low-performance driving will be described.
When the low-capacity operation start signal enters the control unit, the control unit issues a closing signal to the electromagnetic opening / closing valve 27 to close the electromagnetic opening / closing valve 27. That is, the high-pressure lubricating oil in the oil separator 20 is blocked from flowing into the vane chamber 15b provided in the second cylinder 8B. Then, an operation start signal is sent to the electric motor unit 3 to drive the rotary shaft 4 to rotate.
In the first cylinder chamber 12a, the vane 16a is pressed and urged by the spring member 17, and the high-pressure lubricating oil in the oil separator 20 is continuously guided to the vane chamber 15b and filled. A sufficiently high back pressure is applied to the rear end of the vane 16a, and the front end of the vane 16a reliably contacts the circumferential surface of the roller 14a that rotates eccentrically. In the first cylinder chamber 12a, a stable compression operation similar to that in the large capacity operation described above is performed.

On the other hand, when the electromagnetic on-off valve 27 is closed, the high-pressure lubricating oil is not guided to the vane chamber 15b provided in the second cylinder 8B. The high-pressure lubricating oil that is led to and filled in the vane chamber 15b during the previous large-capacity operation leaks from the gap between the vane 16b side surfaces and the vane chamber 15b groove portion that stores the vane 16b as the vane 16b reciprocates.
If the electromagnetic on-off valve 27 is in the open state, the high pressure lubricating oil is introduced into the vane chamber 15b from the oil separator 20 and replenished, so that the high pressure condition can be maintained. However, since the supply is shut off, the vane chamber 15b changes to a low pressure. . Moreover, since the second compression mechanism 2B is immersed in the lubricating oil in the oil reservoir 19, the lubricating oil in the oil reservoir 19 enters through the gap between the vane 16b and the groove 15b and the vane chamber 15b. To ensure low pressure.

By the action of the first compression mechanism portion 2A, the low pressure refrigerant gas is guided to the second cylinder chamber 12b together with the first cylinder chamber 12a, and the second cylinder chamber 12b is in a low pressure atmosphere. Therefore, the tip of the vane 16b is in a low pressure atmosphere, the rear end is also in a low pressure atmosphere, and both ends are under substantially equal pressure conditions.
There is no back pressure urging force against the rear end of the vane 16b, the vane 16b is pushed away by the first rotation of the eccentric roller 14b, and the tip of the vane 16b is separated from the outer peripheral surface of the eccentric roller 14b. At the same time, the rear end of the vane 16b comes into contact with the holding member 18 and is magnetically attracted and held so that the tip of the vane 16b is separated from the peripheral surface of the eccentric roller 14b. Since there is nothing that bisects the second cylinder chamber 12b in contact with the eccentric roller 14b, the eccentric roller 14b rotates idly in the second cylinder chamber 12b.

Eventually, the compression action in the second cylinder chamber 12b is not performed, and the second compression mechanism portion 2B enters a non-compression operation state (also referred to as a cylinder resting state). Only the compression action in the first compression mechanism 2A is effective, and the low-capacity operation that halves the large-capacity operation described above is performed.
In addition, you may provide the low pressure inlet pipe 31 which provided the auxiliary | assistant on-off valve 30 as shown with a dashed-two dotted line in a figure. One end of the low pressure introduction pipe 31 is connected to the inner bottom part of the sealed case 1 and the other end is connected to a midway part of the second branch high pressure introduction pipe 26 b provided with the electromagnetic switching valve 27. The auxiliary on-off valve 30 is controlled to be closed during high capacity operation and to be opened during low capacity operation.

  In particular, when the low-capacity operation is performed, since the electromagnetic on-off valve 27 of the second branch high-pressure introduction pipe 26b is closed, the oil at the bottom of the sealed case 1 is passed through the auxiliary on-off valve 30 opened from the low-pressure introduction pipe 31. Lubricating oil collected in the reservoir 19 is guided to the vane chamber 15b. The sealed case 1 has a low-pressure atmosphere, the lubricating oil in the oil reservoir 19 is a low-pressure lubricating oil, and the vane chamber 15b becomes a low-pressure atmosphere in a short time.

  That is, when switching from the high-capacity operation to the low-capacity operation, the electromagnetic on-off valve 27 is closed and the flow of the high-pressure lubricating oil to the vane chamber 15b is blocked. At the same time, the high-pressure lubricant filled in the vane chamber 15b leaks out of the vane chamber 15b. On the other hand, low-pressure lubricating oil collected in the oil sump 19 at the bottom of the sealed case 1 is introduced into the vane chamber 15 b through the opened auxiliary on-off valve 30 and the low-pressure introduction pipe 31. In the vane chamber 15b, instead of the low pressure condition at an early stage, immediately after the operation is switched, there is no differential pressure at both ends of the vane 16b, and the switching time in which the rear end of the vane 16b is held and fixed to the holding member 18 is shortened. Is obtained.

According to such a hermetic compressor R, the flow rate of the circulating refrigerant can be reduced without reducing the rotational speed of the electric motor unit 3, and the compression efficiency can be improved in a low flow rate region. Since no components of the pressure switching mechanism 25 are required for the suction pipe S that guides the refrigerant to the first cylinder chamber 12a and the second cylinder chamber 12b, there is no generation of suction passage resistance and a high performance compressor. Can provide.
During the low capacity operation, the second cylinder chamber 12b becomes the suction pressure of the compressor R (low pressure of the refrigeration cycle). This is equivalent to the pressure in the sealed case 1, and there is no differential pressure between the second cylinder chamber 12 b and the sealed case 1. Therefore, the refrigerant leak from the second cylinder chamber 12b can be prevented, and the compression performance is prevented from being lowered.

  By switching the electromagnetic on-off valve 27 of the pressure switching mechanism 25, it is possible to switch between the compression operation and the non-compression operation in the second cylinder chamber 12b, and the reliability is improved by acting reliably with a simple configuration. It is done. Since the high-pressure lubricating oil separated by the oil separator 20 is guided to the vane chambers 15a and 15b provided in the first and second cylinders 8A and 8B, it is sufficiently high at the rear ends of the vanes 16a and 16b. Back pressure can be applied and each vane can be operated more reliably.

  Further, the high-pressure lubricant introduced into the vane chambers 15a and 15b leaks out from the gap between the vanes 16a and 16b and the groove portions of the vane chambers 15a and 15b. For this reason, oil supply to the sliding portions of the vanes 16a and 16b is reliably performed, and the vanes 16a and 16b operate more smoothly. In other words, the sealing performance of the vane clearance portion is improved, and a highly efficient and reliable hermetic compressor R can be provided.

In addition, as a refrigerant | coolant used for the refrigerating cycle circuit K, it is good to use either hydrocarbons, such as isobutane and a propane, or a carbon dioxide, for example. In other words, in the hermetic compressor R, since the hermetic case 1 is in a low-pressure condition, the refrigeration cycle circuit K can reduce the amount of enclosed refrigerant, and by using a flammable hydrocarbon-based refrigerant, it is safer. Equipment can be provided. Even when a high-pressure refrigerant such as carbon dioxide is used, there is an advantage that the pressure-resistant design of the sealed case 1 becomes easy.
In addition, the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying constituent elements without departing from the scope of the invention in the implementation stage, and a plurality of components disclosed in the above-described embodiment. Various inventions can be formed by appropriately combining the components.

BRIEF DESCRIPTION OF THE DRAWINGS The longitudinal cross-sectional view and refrigeration cycle block diagram of a hermetic type compressor which concern on one embodiment in this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Sealing case, 3 ... Electric motor part, 4 ... Rotary shaft, 2A ... 1st compression mechanism part, 2B ... 2nd compression mechanism part, 14a, 14b ... Eccentric roller, 12a ... 1st cylinder chamber, 12b ... Second cylinder chamber, 8A ... first cylinder, 8B ... second cylinder, 16a, 16b ... vane, 25 ... pressure switching mechanism, R ... closed compressor, 22 ... condenser, 23 ... expansion mechanism (expansion) Device), 24 ... evaporator, K ... refrigeration cycle circuit.

Claims (2)

In a hermetic compressor including a hermetic case, an electric motor unit accommodated in the hermetic case, and a plurality of compression mechanisms connected to the electric motor unit via a rotating shaft,
The inside of the sealed case has a low pressure atmosphere,
The refrigerant compressed by the plurality of compression mechanisms is discharged through an oil separator provided outside the sealed case,
The plurality of compression mechanisms are each provided with a cylinder chamber in which a roller is housed so as to be eccentrically rotatable, and the tip provided on the cylinder is pressed and urged so as to abut the circumferential surface of the roller to rotate the roller. A vane that bisects the cylinder chamber along the direction, and the rear end side of the vane and the bottom of the oil separator communicate with each other, and high-pressure lubricating oil in the oil separator is communicated from the oil separator bottom to the rear end side of the vane. A high-pressure introduction passage that leads,
At least one compression mechanism in the plurality of compression mechanisms has a pressure switching mechanism that controls communication of the high pressure introduction passage and switches the rear end side of the vane to low pressure or high pressure.
The above-described pressure switching mechanism is operated according to the magnitude of the load, and the high-capacity operation in which the compression operation is performed in all the compression mechanism parts with the vane rear end side in the specific compression mechanism part as a high pressure, and in the specific compression mechanism part A hermetic compressor characterized in that the rear end side of the vane is set to a low pressure and can be switched to a low-capacity operation in which the vane is separated from the roller and is not compressed.   A refrigeration cycle apparatus comprising the hermetic compressor according to claim 1, a condenser, an expansion device, and an evaporator to constitute a refrigeration cycle circuit.

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