JP5286010B2 - 2-cylinder rotary compressor and refrigeration cycle equipment - Google Patents

Description

  The present invention relates to a two-cylinder rotary compressor capable of switching between full-capacity operation and half-capacity operation, and a refrigeration cycle apparatus including the two-cylinder rotary compressor and constituting a refrigeration cycle.

  A two-cylinder rotary compressor having a cylinder chamber in each of the first cylinder constituting the first compression mechanism and the second cylinder constituting the second compression mechanism is often used. In this type of compressor, it is advantageous if variable capacity operation can be performed in which the compression action is performed simultaneously in two cylinder chambers or the compression action in one of the cylinder chambers is interrupted to reduce the compression work.

  For example, a two-cylinder rotary compressor disclosed in [Patent Document 1] includes two cylinder chambers, and includes a compression mechanism including a roller that rotates eccentrically in each cylinder chamber, a blade that elastically contacts the roller, and the like. And a high pressure introducing means for holding the blade of one cylinder chamber away from the roller and increasing the pressure of the cylinder chamber to interrupt the compression action.

In the rotary hermetic compressor disclosed in [Patent Document 2], a vane that bisects the cylinder chamber of the first cylinder and the second cylinder is accommodated in the vane chamber, and the vane on the first cylinder side is a spring member. The vane on the second cylinder side is pressed and urged by a differential pressure between the pressure inside the case guided to the vane chamber and the suction pressure or discharge pressure guided to the cylinder chamber.
JP-A-1-247786 JP 2004-301114 A

  By the way, in such a two-cylinder rotary type compressor capable of switching between full-capacity operation and half-capacity operation, the motor efficiency of the electric motor section decreases as the rotational speed decreases. Therefore, it is necessary to improve motor efficiency by doubling the number of rotations of the rotating shaft in the low capacity range where the capacity is reduced by half.

  In the above-described compressor, the portion with the largest shaft sliding loss is the eccentric portion of the rotating shaft, so the sliding loss at the eccentric portion must be reduced. However, in both the compressors of [Patent Document 1] and [Patent Document 2], as the rotational speed is increased, the shaft sliding loss ratio increases, and it is difficult to improve the motor efficiency during the half-capacity operation. .

  The rotating shaft has a main shaft portion that is supported by the main bearing and a sub shaft portion that is supported by the sub bearing. However, when the eccentric roller is incorporated in the eccentric portion of the rotating shaft, the axial length is reduced. If the eccentric roller is inserted from the side of the sub shaft shorter than the main shaft, the operation can be easily performed. Therefore, in order to make the insertion of the eccentric roller easier, it can be considered that the shaft diameter of the auxiliary shaft portion is simply set small.

  However, if the shaft diameter of the auxiliary shaft portion is simply set to be small, the surface pressure of the shaft surface of the auxiliary shaft portion is likely to increase during actual compression operation. In particular, it becomes difficult to form an oil film of a lubricating oil in a low rotation range (low performance range), leading to a decrease in reliability.

  The present invention has been made on the basis of the above circumstances. The purpose of the present invention is a two-cylinder type, on the premise that the capacity can be varied between full capacity operation and half capacity operation, while ensuring reliability. An attempt is made to provide a two-cylinder rotary compressor that can reliably improve the motor efficiency during half operation, and a refrigeration cycle apparatus that includes this two-cylinder rotary compressor and that can improve the refrigeration cycle efficiency. To do.

In order to satisfy the above object, a two-cylinder rotary compressor of the present invention houses an electric motor part and a compression mechanism part in a hermetic container, and the compression mechanism part has an inner diameter part with an intermediate partition plate interposed therebetween. The first cylinder and the second cylinder are provided, and the main bearing that forms the first cylinder chamber is formed on the motor part side of the first cylinder so as to cover the intermediate partition plate and the inner diameter part of the first cylinder, A sub-bearing that covers the intermediate partition plate and the inner diameter portion of the second cylinder to form a second cylinder chamber is attached to the counter-motor portion side of the cylinder, and the rotary shaft connected to the motor portion is connected to the first cylinder chamber and the second cylinder chamber . One eccentric portion is provided in each of the two cylinder chambers, and the eccentric portion of the first cylinder chamber and the eccentric portion of the second cylinder chamber are arranged at positions where the rotation angles are shifted from each other by 180 °. A main shaft portion that is supported, and a sub-shaft portion that is supported by the auxiliary bearing; It is possible to switch between compression operation and non-compression operation in the second cylinder chamber by fitting an eccentric roller to the eccentric portion of the rotation shaft and rotationally driving it in the first cylinder chamber and the second cylinder chamber. The sub-shaft portion shaft diameter φDb of the rotary shaft that is pivotally supported by the sub-bearing is configured so that the formula (1) is established.

φDa: The diameter of the main shaft portion of the rotary shaft supported by the main bearing. L1: An axial distance from the axial center position of the first cylinder to the axial load position of the rotary shaft main shaft portion (distance half the main shaft portion shaft diameter from the first cylinder chamber side end portion of the main shaft portion). L2: An axial distance from the axial center position of the first cylinder to the axial center position of the second cylinder. L3: Axial distance from the axial center position of the second cylinder to the axial load position of the rotary shaft countershaft portion (distance from the second cylinder chamber side end of the subshaft portion to a half of the shaft diameter of the subshaft portion) . L4: sliding length between the eccentric portion of the rotating shaft and the eccentric roller. E: The amount of eccentricity of the eccentric part of the rotating shaft.
In order to satisfy the above object, a refrigeration cycle apparatus of the present invention comprises the above-described two-cylinder rotary compressor, a condenser, an expansion device, and an evaporator to constitute a refrigeration cycle.

  According to the present invention, it is possible to reliably improve the motor efficiency during half-capacity operation while ensuring reliability on the premise that the two-cylinder type is capable of variable capacity between full-capacity operation and half-capacity operation. It is possible to provide a two-cylinder rotary compressor and a refrigeration cycle apparatus that includes this two-cylinder rotary compressor and that can improve the refrigeration cycle efficiency.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a longitudinal sectional view of a two-cylinder rotary compressor R and a diagram showing a refrigeration cycle configuration of a refrigeration cycle apparatus. FIG. 2 is an enlarged longitudinal section of a main part of the two-cylinder rotary compressor R. FIG. 3 is an exploded perspective view of a part of the two-cylinder rotary compressor R. (In order to avoid complications in the drawings, there are parts that are not denoted by reference numerals even if they are explained, and there are parts that are not explained even if they are shown. The same applies hereinafter).
First, a description will be given of the two-cylinder rotary compressor R. Reference numeral 1 denotes a sealed container, in which a compression mechanism unit 3 is provided in the lower part and the motor part 4 is provided in the upper part. The compression mechanism unit 3 and the motor unit 4 are connected by a rotating shaft 5.

  The compression mechanism section 3 includes a first cylinder 6A on the upper surface portion of the intermediate partition plate 2 via the intermediate partition plate 2, and a second cylinder 6B on the lower surface portion. Further, the main bearing 7 is attached and fixed to the upper surface portion of the first cylinder 6A, and the auxiliary bearing 8 is attached and fixed to the lower surface portion of the second cylinder 6B.

  The main bearing 7 supports the main shaft portion 5 a of the rotating shaft 5, and the auxiliary bearing 8 supports the auxiliary shaft portion 5 b of the rotating shaft 5. Further, the rotating shaft 5 penetrates through the first and second cylinders 6A and 6B, and the first eccentric part a and the second eccentric part b formed with a phase difference of about 180 ° are integrated. I have.

  The first and second eccentric parts a and b have the same shaft diameter and are assembled so as to be positioned at the inner diameter parts of the first and second cylinders 6A and 6B. A first eccentric roller 9a is fitted to the peripheral surface of the first eccentric part a, and a second eccentric roller 9b is fitted to the peripheral surface of the second eccentric part b.

  An inner diameter portion of the first cylinder 6A is surrounded by the main bearing 7 and the intermediate partition plate 2, and a first cylinder chamber Sa is formed. The inner diameter portion of the second cylinder 6B is surrounded by the auxiliary bearing 8 and the intermediate partition plate 2, and a second cylinder chamber Sb is formed.

  The cylinder chambers Sa and Sb are formed to have the same shaft diameter and height, and the eccentric rollers 9a and 9b are partly accommodated so that they can be eccentrically rotated while being in line contact with the peripheral walls of the cylinder chambers Sa and Sb. Is done.

  In particular, as shown in FIG. 3, the first cylinder 6A is provided with a first vane chamber 10a communicating with the first cylinder chamber Sa, and the first vane 11a is movably accommodated therein. The second cylinder 6B is provided with a second vane chamber 10b communicating with the second cylinder chamber Sb, and the second vane 11b is movably accommodated therein.

  The tip ends of the first and second vanes 11a and 11b are formed in a semicircular shape in a plan view, and project into the opposing cylinder chambers Sa and Sb to have a circular shape in the plan view. Line contact can be made with the peripheral walls of the rollers 9a and 9b regardless of the rotation angle.

  Only the first cylinder 6A is provided with a lateral hole f that communicates the first vane chamber 10a with the outer peripheral surface of the cylinder 6A, and accommodates a spring member 12 that is a compression spring. The spring member 12 is interposed between the rear end side end face of the first vane 11a and the inner peripheral wall of the sealed container 1, and applies an elastic force (back pressure) to the vane 11a.

  The second vane chamber 10b contains no members other than the second vane 11b. However, depending on the setting environment of the second vane chamber 10b and the operation of the switching mechanism K as will be described later. The tip edge of the second vane 11b can come into contact with the peripheral surface of the second eccentric roller 9b.

  That is, a part of the outer shape of the second cylinder 6B is exposed in the sealed container 1 due to the relationship between the outer dimensions of the second cylinder 6B and the outer diameters of the intermediate partition plate 2 and the auxiliary bearing 8. The exposed portion of the hermetic container 1 is designed to correspond to the vane chamber 10b. Therefore, the rear end portions of the vane chamber 10b and the vane 11b directly receive the pressure in the case.

  In particular, since the second cylinder 6B and the second vane chamber 10b are structures, there is no influence even if they are subjected to pressure inside the case, but the second vane 11b is slidable in the second vane chamber 10b. And the rear end thereof is located in the second vane chamber 10b, so that the pressure in the sealed container 1 is directly received.

  Furthermore, the tip of the second vane 11b faces the second cylinder chamber Sb, and the tip of the vane 11b receives the pressure in the cylinder chamber Sb. Eventually, the second vane 11b is configured to move in a direction from a higher pressure to a lower pressure according to the mutual pressure received by the front end and the rear end.

  As shown in FIG. 1 again, a refrigerant pipe P is connected to the upper end of the sealed container 1. The refrigerant pipe P is connected to an accumulator 18 through a condenser 15, an expansion device 16, and an evaporator 17, and further connected from the accumulator 18 to the two-cylinder rotary compressor R to constitute a refrigeration cycle.

  More specifically, two suction refrigerant pipes Pa and Pb are connected to the two-cylinder rotary compressor R from the bottom of the accumulator 18. One suction refrigerant pipe Pa penetrates the sealed container 1 and the side of the first cylinder 6A, and communicates directly with the first cylinder chamber Sa. The other suction refrigerant pipe Pb passes through the side of the second cylinder 6B via the hermetic container 1 and directly communicates with the second cylinder chamber Sb.

  Further, a branch refrigerant pipe Pc is branched from a midway part of the refrigerant pipe P communicating with the two-cylinder rotary compressor R and the condenser 15. The branch refrigerant pipe Pc is provided with a first on-off valve 20 in the middle, and is connected to a middle part of the suction refrigerant pipe Pb that communicates the accumulator 18 and the second cylinder chamber Sb.

  Furthermore, a second on-off valve 21 is provided upstream of the connection portion of the branch refrigerant pipe Pc in the suction refrigerant pipe Pb. Each of the first on-off valve 20 and the second on-off valve 21 is an electromagnetic on-off valve.

  Thus, the switching mechanism K is constituted by the suction refrigerant pipe Pb, the branch refrigerant pipe Pc, the first on-off valve 20 and the second on-off valve 21 connected to the second cylinder chamber Sb. In accordance with the switching operation of the switching mechanism K, the suction pressure or the discharge pressure is guided to the cylinder chamber Sb of the second cylinder 6B.

  Next, the operation of the refrigeration cycle apparatus including the above-described two-cylinder rotary compressor R will be described.

a) When normal operation (full capacity operation) is selected:
When a normal operation instruction is input, the control unit controls the first on-off valve 20 of the switching mechanism K to be closed and the second on-off valve 21 to be opened, and the operation signal is sent to the motor unit 4 via the inverter. Send. The rotary shaft 5 is rotationally driven, and the first and second eccentric rollers 9a and 9b simultaneously perform eccentric rotation in the first and second cylinder chambers Sa and Sb.

  In the first cylinder 6A, since the first vane 11a is always elastically pressed and biased by the spring member 12, the leading edge of the first vane 11a is in sliding contact with the peripheral wall of the first eccentric roller 9a. The first cylinder chamber Sa is divided into a suction chamber and a compression chamber.

  The first cylinder chamber Sa is in a state in which the position of the inner peripheral surface of the first cylinder chamber Sa to which the peripheral surface of the first eccentric roller 9a is in rolling contact is coincident with the tip of the first vane 11a and the first vane 11a is most retracted. The space capacity of Sa is maximized. The refrigerant gas is sucked into the first cylinder chamber Sa from the accumulator 18 through the suction refrigerant pipe Pa and is filled.

  Further, along with the eccentric rotation of the first eccentric roller 9a, the rolling contact position of the first eccentric roller 9a with the inner peripheral surface of the first cylinder chamber Sa moves and the first cylinder chamber Sa is partitioned. The volume of the compression chamber is reduced. That is, the gas previously introduced into the first cylinder chamber Sa is gradually compressed.

  The rotary shaft 5 is continuously rotated, the capacity of the compression chamber partitioned into the first cylinder chamber Sa is further reduced, the gas is compressed, and the discharge valve is opened when the pressure rises to a predetermined pressure. The high pressure gas is discharged into the sealed container 1 through the valve cover and is filled. And it discharges from the refrigerant | coolant pipe | tube P connected to the airtight container 1 upper part.

  On the other hand, since the first on-off valve 20 constituting the switching mechanism K is closed, the discharge pressure (high pressure) is not led to the second cylinder chamber Sb. Since the second on-off valve 21 is opened, the low-pressure evaporative refrigerant evaporated by the evaporator 17 and gas-liquid separated by the accumulator 18 is guided to the second cylinder chamber Sb.

  The second cylinder chamber Sb is in a suction pressure (low pressure) atmosphere, while the second vane chamber 10b is exposed in the sealed container 1 and is under a discharge pressure (high pressure). In the 2nd vane 11b, the front-end | tip part becomes low-pressure conditions, and a rear-end part becomes high-pressure conditions, and a differential pressure | voltage exists in a front-and-back end part.

  Due to the effect of this differential pressure, the tip of the second vane 11b is pressed and urged so as to be in sliding contact with the second eccentric roller 9b. Therefore, the compression action is performed also in the second cylinder chamber Sb, and the full capacity operation is performed in which the compression action is performed in both the first cylinder chamber Sa and the second cylinder chamber Sb.

  The high-pressure gas discharged from the sealed container 1 through the refrigerant pipe P is condensed and liquefied by exchanging heat with outside air or water in the condenser 15, adiabatically expanded in the expansion device 16, and evaporated from the heat exchange air in the evaporator 17. Takes out latent heat and freezes.

  Then, the evaporated refrigerant is guided to the accumulator 18 and separated into gas and liquid, and again from the suction refrigerant pipes Pa and Pb to the first cylinder chamber Sa and the second cylinder chamber Sb2 in the two-cylinder rotary compressor R. Inhaled, the above-mentioned action is performed, and the above-mentioned route is circulated.

b) When special operation (capacity half operation) is selected:
When the special operation (operation that halves the compression capacity) is selected, the switching mechanism K switches and sets so that the first on-off valve 20 is opened and the second on-off valve 21 is closed. In the first cylinder chamber Sa, the normal compression action is performed as described above, and the high-pressure gas discharged into the hermetic container 1 is filled to become a high pressure in the case.

  A part of the high-pressure gas discharged from the refrigerant pipe P is divided into the branch refrigerant pipe Pc, and is introduced into the second cylinder chamber Sb through the opened first on-off valve 20 and the suction refrigerant pipe Pb. While the second cylinder chamber Sb is in a discharge pressure (high pressure) atmosphere, the second vane chamber 10b remains in the same situation as the high pressure in the case.

  Therefore, the second vane 11b is affected by the high pressure at both the front and rear ends, and there is no differential pressure at the front and rear ends. The second vane 11b is kicked with the rotation of the eccentric roller 9b, and keeps the stopped state at a position away from the peripheral surface.

  The second eccentric roller 9b remains idling, and no compression action is performed in the second cylinder chamber Sb (non-compression operation state). Eventually, only the compression action in the first cylinder chamber Sa is effective, and an operation with half the capacity is performed.

  Note that the switching mechanism K that switches between the compression operation and the non-compression operation in the second cylinder chamber Sb is not limited to that shown in the above embodiment. For example, the pressure in the second vane chamber 10b is switched between high pressure and low pressure, the compression operation is performed in the second cylinder chamber Sb when the pressure in the second vane chamber 10b is high, and the non-compression operation is performed when the pressure is low. May be performed.

As described above, in the two-cylinder rotary compressor R that enables switching between the compression operation and the non-compression operation in the cylinder chamber on the side of the auxiliary bearing 8, that is, the second cylinder chamber Sb, the auxiliary bearing 8 is pivotally supported. The subshaft portion 5b shaft diameter φDb of the rotating shaft 5 is set so that the following expression (1) is established.

Here, φDa: the diameter of the main shaft portion 5a of the rotary shaft 5 supported by the main bearing 7.
L1: The axial load position of the rotary shaft main shaft portion 5a from the axial center position of the first cylinder 6A (the distance Da / 2 from the end of the main shaft portion 5a on the first cylinder chamber Sa side to a half of the main shaft portion 5a shaft diameter φDa) Axial distance to).
L2: An axial distance from the axial center position of the first cylinder 6A to the axial center position of the second cylinder 6B.
L3: The axial load position of the rotary shaft countershaft portion 5b from the axial center position of the second cylinder 6B (the distance half the shaft diameter φDb from the end of the subshaft portion 5b on the second cylinder chamber Sa side to the subshaft portion 5b) Axial distance to Db / 2).
L4: A sliding length between the eccentric portion b of the rotating shaft 5 and the eccentric roller 9b.
E: The amount of eccentricity of the eccentric part b of the rotating shaft 5.

  That is, in the above-described two-cylinder rotary compressor R, the efficiency of the motor that is the electric motor section 4 is reduced when the rotational speed of the rotary shaft 5 is reduced. Therefore, in the low capacity region, the second cylinder chamber Sb is in an uncompressed operation state (hereinafter referred to as “cylinder operation”), and the motor efficiency is controlled to be increased by doubling the rotational speed. .

  However, in this case, the shaft sliding loss is increased by increasing the rotation speed, and in the design specification having a large shaft sliding loss ratio, the motor efficiency cannot be improved by the cylinder resting operation. In particular, in the two-cylinder rotary compressor R, the portions with the largest shaft sliding loss are the eccentric portions a and b formed on the rotary shaft 5, and therefore it is necessary to reduce the sliding loss at these eccentric portions a and b. There is.

  As shown in FIG. 2 in an enlarged manner, the sliding length of the first eccentric portion a and the second eccentric portion b formed on the rotating shaft 5 with respect to the first eccentric roller 9a and the second eccentric roller 9b. Is L4, and the shaft diameters of the first eccentric part a and the second eccentric part b are φDcr.

  FIG. 4 is a characteristic diagram of L4 / φDcr and eccentric part sliding loss when (L4 / φDcr) is taken on the horizontal axis and eccentric part sliding loss [W] is taken on the vertical axis. Comparisons are made under the same capacity for both the hour and the idle cylinder operation.

The value of the eccentric portion sliding loss [W] is set such that the sliding length L4 of the first and second eccentric portions a and b with respect to the first and second eccentric rollers 9a and 9b is constant, The second eccentric portion shaft diameter φDcr is changed and led. Further, it is assumed that the number of revolutions during the cylinder resting operation is twice that during the two cylinder operation, and the sliding loss of the second eccentric portion b which is the cylinder eccentric side eccentric portion is “0”.
The change during the two-cylinder operation is indicated by a broken line, and the change during the non-cylinder operation is indicated by a solid line. From this figure, it can be seen that the loss difference increases as the L4 / φDcr value decreases.

FIG. 5 is a characteristic diagram of L4 / φDcr and total efficiency at the same capacity under the cooling intermediate condition as an air conditioner. Also here, L4 / φDcr is taken on the horizontal axis, the eccentric portion sliding length L4 is constant, and the eccentric portion shaft diameter φDcr is changed. The vertical axis is the overall efficiency.
From this figure, in order to obtain the efficiency improvement due to idle cylinder operation,
L4 / φDcr ≧ 0.43 (2)
It is necessary to satisfy the formula (2).

The measurement conditions for obtaining the above-mentioned cooling intermediate conditions are shown in [Table 1] below.

In Table 1, kPaA is an absolute pressure.

As shown in FIG. 2 again, the first eccentric portion a has a first diameter between the shaft diameter φDcr of the first and second eccentric portions a and b and the shaft diameter φDb of the auxiliary shaft portion 5b. In order to incorporate the eccentric roller 9a from the auxiliary shaft portion 5b side
φDcr ≧ φDb + 2 × E (3)
It is necessary to satisfy the formula (3).

Therefore, as a condition for expanding the expressions (2) and (3) and obtaining the efficiency improvement by the idle cylinder operation,
φDb ≦ L4 / 0.43-2 × E (4)
(4) Formula must be satisfied.

  On the other hand, as the shaft diameter φDb of the auxiliary shaft portion 5b is reduced, the surface pressure with respect to the shaft surface increases, and the oil film of the lubricating oil is difficult to be formed particularly in the low rotation region (low performance region), and the reliability deteriorates. .

In the above-described two-cylinder rotary compressor R, in order to rest the second cylinder chamber Sb on the side of the auxiliary shaft portion 5b in the low capacity region, the gas load Fa applied to the main shaft portion 5a of the rotating shaft 5, The ratio with the gas load Fb applied to the shaft portion 5b is as shown in FIG.
Fa: Fb = (L2 + L3): 1 (5)
It becomes.

Further, the ratio of the surface pressure Pa to the main shaft portion 5a and the surface pressure Pb to the sub shaft portion 5b is such that the sliding length ratio under load is equal to the shaft diameter ratio.
Pa: Pb = (L2 + L3) / φDa ² : L1 / φDb ² (6)
It becomes.

Here, in order to ensure a surface pressure equal to or greater than that of the main shaft portion 5a in the sub shaft portion 5b of the rotating shaft 5,

It is necessary to satisfy the formula (7).

So from these things

Equation (1) is derived.
That is, by satisfying the above-described expression (1), it is possible to sufficiently improve the efficiency by the idle cylinder operation while ensuring the reliability.

Table 2 below is a design example that specifically expresses the expression (1).

  And the refrigerating cycle apparatus which comprises such a 2 cylinder rotary compressor R and comprises a refrigerating cycle can obtain the improvement of refrigerating efficiency further.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the above-described embodiments.

1 is a schematic longitudinal sectional view of a two-cylinder rotary compressor and a refrigeration cycle configuration diagram of a refrigeration cycle apparatus according to an embodiment of the present invention. The expanded longitudinal cross-sectional view of the 2-cylinder rotary compressor principal part which concerns on the same embodiment. The partial exploded perspective view of the 2-cylinder rotary compressor principal part which concerns on the embodiment. The characteristic figure of the eccentric part sliding loss with respect to the eccentric part sliding length / eccentric part axial diameter based on the embodiment. The characteristic figure of the total efficiency with respect to the eccentric part sliding length / eccentric part axial diameter based on the embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Sealed container, 4 ... Electric motor part, 3A ... 1st compression mechanism part, 3B ... 2nd compression mechanism part, 2 ... Intermediate partition plate, 6A ... 1st cylinder, 6B ... 2nd cylinder, Sa ... 1st cylinder chamber, 7 ... main bearing, Sb ... 2nd cylinder chamber, 8 ... sub bearing, a ... 1st eccentric part, b ... 2nd eccentric part, 5 ... rotating shaft, 9a ... 1st Eccentric roller, 9b ... second eccentric roller, K ... switching mechanism, R ... two-cylinder rotary compressor, 15 ... condenser, 16 ... expansion device, 17 ... evaporator.

Claims (2)

The motor part and the compression mechanism part are accommodated in the sealed container,
The compression mechanism is
A first cylinder and a second cylinder each provided with an intermediate partition plate, each having an inner diameter;
A main bearing attached to the motor part side of the first cylinder and covering the inner diameter part of the first cylinder together with the intermediate partition plate to form a first cylinder chamber;
A sub-bearing attached to the anti-motor part side of the second cylinder and covering the inner diameter part of the second cylinder together with the intermediate partition plate to form a second cylinder chamber;
Each of the first cylinder chamber and the second cylinder chamber is provided with an eccentric portion, and the eccentric portion of the first cylinder chamber and the eccentric portion of the second cylinder chamber are shifted from each other by 180 °. Placed in
A main shaft portion that is pivotally supported by the main bearing, and a rotary shaft that is pivotally supported by the sub-bearing and is coupled to the electric motor portion;
An eccentric roller fitted into each of the eccentric portions of the rotating shaft and driven to rotate in the first cylinder chamber and the second cylinder chamber;
A switching mechanism for switching between compression operation and non-compression operation in the second cylinder chamber;
A two-cylinder rotary compressor comprising:
The shaft diameter φDb of the auxiliary shaft portion of the rotary shaft supported by the auxiliary bearing is:

φDa: Main shaft portion shaft diameter of the rotating shaft supported by the main bearing L1: From the axial center position of the first cylinder to the axial load position of the rotating shaft main shaft portion (from the first cylinder chamber side end of the main shaft portion to the main shaft L2: Axial distance from the axial center position of the first cylinder to the axial center position of the second cylinder L3: Axial center position of the second cylinder Axial distance from the shaft load position of the rotary shaft subshaft portion (the distance from the second cylinder chamber side end of the subshaft portion to the half of the shaft diameter of the subshaft portion) L4: Eccentric portion and eccentric roller of the rotary shaft Sliding length E: Eccentric amount of the eccentric portion of the rotating shaft A two-cylinder rotary compressor characterized in that the above formula (1) is established.   A refrigeration cycle apparatus comprising the two-cylinder rotary compressor according to claim 1, a condenser, an expansion device, and an evaporator to constitute a refrigeration cycle.

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