WO2018051567A1

WO2018051567A1 - Rotary compressor and refrigeration cycle device

Info

Publication number: WO2018051567A1
Application number: PCT/JP2017/015299
Authority: WO
Inventors: 平山　卓也; 鈴木　秀明; 昌宏畑山
Original assignee: 東芝キヤリア株式会社
Priority date: 2016-09-14
Filing date: 2017-04-14
Publication date: 2018-03-22
Also published as: CN109072917A; EP3514391B1; EP3514391A1; JP6703921B2; EP3514391A4; CN109072917B; JP2018044489A

Abstract

Provided are: a rotary compressor which is compact and has a large discharge capacity; and a refrigeration cycle device. This rotary compressor 2 has a maximum operating fluid discharge pressure of 3 MPa or higher. If the inner diameter of cylinder chambers 20a, 20b is designated D1, the sum of the heights of the cylinder chambers 20a, 20b is designated H, the distance from the upper end of a stator 14 to the upper inner wall surface of an enclosed case 7 is designated L1, the inner cross-sectional area of the inner case 7 is designated Ac, the total cross-sectional area of a discharge flow passage 15 is designated Ad, and the thickness of the stator core 14a of the stator 14 is designated T, then all of the following expressions (1)-(3) are satisfied: (1) 0.85 × D1 < H < L1, (2) 0.06 < Ad/Ac < 0.13, and (3) 1.2 < T/H < 1.5.

Description

Rotary compressor and refrigeration cycle apparatus

Embodiments of the present invention relate to a rotary compressor and a refrigeration cycle apparatus using the rotary compressor.

Operation that is compressed and discharged in a rotary compressor that accommodates an electric motor and a compression mechanism that is driven via a rotary shaft connected to the electric motor in a sealed case and compresses a working fluid such as a refrigerant. Various measures have been taken to increase the fluid discharge capacity. For example, the measures described in Patent Document 1 below have been taken.

In the rotary compressor described in Patent Document 1, when the inner diameter of the cylinder chamber is D and the height of the cylinder chamber is H, H / D ≦ 0.4 for the one cylinder type and H / D for the two cylinder type. ≦ 0.3.

Japanese Patent No. 4864572

However, in the rotary compressor described in Patent Document 1, in order to increase the discharge capacity, it is necessary to increase the inner diameter of the cylinder chamber, and accordingly, the inner diameter of the sealed case also increases, so the pressure resistance decreases. To do. In particular, when the discharge pressure is high, it is necessary to increase the thickness of the sealed case, resulting in an increase in the size, weight, and resource saving of the rotary compressor. For this reason, it is conceivable to increase the discharge capacity without increasing the H / D and without increasing the inner diameter of the sealed case. In this case, however, the diameter of the motor cannot be increased. Then, the compression load torque was excessive, and the compressor efficiency was reduced.

An object of an embodiment of the present invention is to provide a rotary compressor having a small discharge capacity and a large discharge capacity, and a refrigeration cycle apparatus using the rotary compressor.

According to the rotary compressor of the embodiment, a sealed case, an electric motor having six or more poles accommodated in the upper part of the sealed case, and a rotary shaft accommodated in the lower part of the sealed case and connected to the electric motor And a discharge pipe provided at the top of the sealed case. The compression mechanism has two cylinders that are closed at both the upper and lower ends and in which a cylinder chamber is formed. Then, the roller fitted to the rotating shaft in the cylinder chamber rotates eccentrically to compress the working fluid, and the compressed working fluid in the cylinder chamber is discharged into the sealed case. The electric motor rotates integrally with the rotating shaft. A discharge passage for guiding the working fluid discharged from the cylinder chamber to the discharge pipe side is formed, and the maximum discharge pressure of the working fluid is 3 MPa or more. In rotary compressor, The inner diameter of the Linda chamber is D1, the total height of the cylinder chambers of the two cylinders is H, the distance from the upper end of the stator to the upper inner wall surface of the sealed case is L1, the inner sectional area of the sealed case is Ac, and the discharge flow path The following relational expressions (1) to (3) are all satisfied, where Ad is the total cross-sectional area of T and T is the thickness of the stator core of the stator.

(1) 0.85 × D1 <H <L1
(2) 0.06 <Ad / Ac <0.13
(3) 1.2 <T / H <1.5

Thereby, it is possible to obtain a rotary compressor having a small discharge capacity and a large discharge capacity, and a refrigeration cycle apparatus using the rotary compressor.

It is the schematic of the refrigerating-cycle apparatus containing the rotary compressor shown by sectional drawing. It is a graph which shows COP ratio at the time of changing ratio of the height of a cylinder chamber, and an internal diameter in a 4-pole motor and a 6-pole motor. It is a graph which shows the relationship between Ad / Ac and the amount of lubricating oil discharged. It is a graph which shows the relationship between Ad / Ac and the efficiency ratio of an electric motor. It is a graph which shows the relationship between T / H and the efficiency ratio of an electric motor. It is a graph which shows the relationship between T / H and the ratio of the pressure loss of a discharge flow path. It is a graph which shows D2 / H and COP ratio.

An outline of the refrigeration cycle apparatus of the embodiment will be described with reference to FIG. As shown in FIG. 1, a refrigeration cycle apparatus 1 includes a rotary compressor 2, a condenser 3 that is a radiator connected to the rotary compressor 2, an expansion device 4 connected to the condenser 3, And an evaporator 5 that is a heat absorber connected to the expansion device 4. The rotary compressor 2 is provided with an accumulator 6. In this refrigeration cycle apparatus 1, the refrigerant that is the working fluid circulates while changing in phase between a gaseous gas refrigerant and a liquid liquid refrigerant, and is dissipated in the process of phase change from the gas refrigerant to the liquid refrigerant. Heat is absorbed during the phase change of the gas refrigerant, and heating, cooling, heating, cooling, and the like are performed using these heat dissipation and heat absorption.

In the rotary compressor 2, the gas refrigerant is compressed. In the condenser 3, the compressed gas refrigerant is condensed into a liquid refrigerant. In the expansion device 4, the condensed liquid refrigerant is decompressed. In the evaporator 5, the decompressed liquid refrigerant evaporates to become a gas refrigerant. In the accumulator 6 of the rotary compressor 2, when the liquid refrigerant is contained in the gas refrigerant evaporated in the evaporator 5, the liquid refrigerant is removed.

The rotary compressor 2 has a cylindrical sealed case 7 that is closed at both upper and lower ends to be airtight. An electric motor 8 is accommodated in an upper portion of the sealed case 7, and a gas is disposed in a lower portion of the sealed case 7. The compression mechanism part 9 which is a part which compresses a refrigerant | coolant is accommodated. A rotating shaft 10 is connected to the electric motor 8, and the compression mechanism unit 9 is driven through the rotating shaft 10. The gas refrigerant compressed by the compression mechanism 9 is discharged into the sealed case 7, and the sealed case 7 is filled with high-pressure gas refrigerant. A discharge pipe 11 is provided in the upper part of the sealed case 7, and the high-pressure gas refrigerant in the sealed case 7 is guided to the condenser 3 through the discharge pipe 11. A lubricating oil 12 is stored at the bottom of the sealed case 7.

The electric motor 8 includes a rotor 13 that is fixed to the rotating shaft 10 and rotates integrally with the rotating shaft 10, and a stator 14 that surrounds the outer periphery of the rotor 13, and has six or more poles. ing. The rotor 13 includes a rotor core 13a in which electromagnetic steel plates are laminated, and a plurality of permanent magnets 13b inserted into the rotor core 13a. The stator 14 has a stator core 14a in which electromagnetic steel plates are laminated, and a field winding 14b wound around the stator core 14a. In addition, the electric motor 8 includes a plurality of discharge passages 15, such as a rotor 13, that guide the gas refrigerant discharged from the compression mechanism 9 into the sealed case 7 to the discharge pipe 11 side, which is the upper side of the sealed case 7. A through hole formed so as to penetrate in the vertical direction, a gap between the inner peripheral surface of the sealing case 7 and the outer peripheral surface of the stator 14, and a gap between the outer peripheral surface of the rotor 13 and the inner peripheral surface of the stator 14 are formed. Has been.

The compression mechanism unit 9 includes two

cylinders

16a and 16b arranged in the vertical direction, a partition plate 17 arranged between the

cylinders

16a and 16b and closing one end face of the

cylinders

16a and 16b, The main bearing 18 which is one bearing which is disposed on the motor 8 side which is the upper side of the cylinder 16a and closes the upper end surface of the cylinder 16a and the motor 8 which is the lower side of the other cylinder 16b are opposite to the motor 8. The auxiliary bearing 19 is the other bearing that is disposed and closes the lower end face of the cylinder 16b. A cylinder chamber 20a is formed inside the cylinder 16a whose both end surfaces are closed by the main bearing 18 and the partition plate 17, and the cylinder chamber 20a is formed inside the cylinder 16b whose both end surfaces are closed by the partition plate 17 and the auxiliary bearing 19. A chamber 20b is formed. A rotary shaft 10 is inserted through the

cylinders

16 a and 16 b, and the rotary shaft 10 is pivotally supported by a main bearing 18 and a sub bearing 19.

The rotary shaft 10 is formed with two columnar

eccentric portions

21a and 21b. One eccentric portion 21a is disposed in the cylinder chamber 20a, and the other eccentric portion 21b is disposed in the cylinder chamber 20b. Yes. A roller 22a is fitted to the eccentric portion 21a, and a roller 22b is fitted to the eccentric portion 21b. These

rollers

22a and 22b are provided so as to be eccentrically rotated while the outer peripheral surface thereof is in sliding contact with the inner peripheral surfaces of the

cylinder chambers

20a and 20b as the rotary shaft 10 rotates. The cylinder 16a is provided with a reciprocating blade 23a, and the cylinder 16b is provided with a reciprocating blade 23b. These

blades

23a, 23b have tips at the outer peripheral surfaces of the

rollers

22a, 22b. The

cylinder chambers

20a and 20b are partitioned into a suction chamber for sucking in the low-pressure gas refrigerant and a compression chamber for compressing the sucked-in gas refrigerant.

The main bearing 18 is provided with a discharge hole 24a and a discharge valve 25a for discharging the gas refrigerant compressed in the cylinder chamber 20a into the sealed case 7. The sub bearing 19 is provided with a discharge hole 24 b and a discharge valve 25 b for discharging the gas refrigerant compressed in the cylinder chamber 20 b into the sealed case 7.

A muffler case 26a is attached to the main bearing 18 at a position surrounding the discharge valve 25a, and the gas refrigerant discharged by opening the discharge valve 25a is discharged into the muffler case 26a and then formed in the muffler case 26a. The discharge hole 27 is discharged into the sealed case 7. A muffler case 26b is attached to the auxiliary bearing 19 at a position surrounding the discharge valve 25b, and the gas refrigerant discharged by opening the discharge valve 25b is discharged into the muffler case 26b and then passes through a communication path (not shown). Then, it flows into the muffler case 26a and is discharged into the sealed case 7 from the discharge hole 27 of the muffler case 26a.

Here, the rotary compressor 2 is set so that the maximum discharge pressure of the gas refrigerant during operation is 3 megapascals (MPa) or more, and the dimensions of each part in the rotary compressor 2 are as follows. explain in detail.

The

cylinder chambers

20a and 20b have the same inner diameter, and the

cylinder chambers

20a and 20b have an inner diameter D1.

The height of one cylinder chamber 20a is H1, the height of the other cylinder chamber 20b is H2, and the total height H of the two

cylinder chambers

20a and 20b is (H = H1 + H2).

The distance from the upper end of the stator 14 to the upper inner wall surface of the sealed case 7 is L1.

The cross-sectional area of the space inside the sealed case 7 is Ac.

The total cross-sectional area of the discharge channel 15 is Ad.

The thickness of the stator core 14a of the stator 14 is T.

The dimensions described above are set so that the following relational expressions (1) to (3) are all satisfied.

(1) 0.85 × D1 <H <L1
(2) 0.06 <Ad / Ac <0.13
(3) 1.2 <T / H <1.5
Next, in the horizontal cross section at the position of the

cylinders

16a and 16b in the sealed case 7, the average cross-sectional area of the space S formed outside the

cylinder chambers

20a and 20b and extending in the vertical and circumferential directions is Av. .

Further, the distance from the lower end of the rotor 13 of the electric motor 8 to the lower inner wall surface of the sealed case 7 is L2.

The dimensions described above are set so that the following relational expressions (4) and (5) are established.

(4) Av / Ac> 0.1
(5) H <L2 / 2
Next, the inner diameter of the main bearing 18 and the auxiliary bearing 19 is D2.

The dimensions described above are set so that the following relational expression (6) is established.

(6) 0.3 <D2 / H <0.4
In such a configuration, the compressor 13 is driven by the rotation of the rotor 13 and the rotating shaft 10 by energization of the electric motor 8. By driving the compression mechanism 9, the low-pressure gas refrigerant passes through the accumulator 6 and is sucked into the

cylinder chambers

20a and 20b. The sucked gas refrigerant is compressed in the

cylinder chambers

20a and 20b.

The gas refrigerant compressed to high pressure in the cylinder chamber 20a is discharged from the discharge valve 25a into the muffler case 26a and discharged into the sealed case 7 from the discharge hole 27 of the muffler case 26a. The gas refrigerant compressed to high pressure in the cylinder chamber 20b is discharged from the discharge valve 25b into the muffler case 26b and flows into the muffler case 26a through a communication path (not shown). It is discharged from the discharge hole 27 into the sealed case 7. The gas refrigerant discharged from the discharge hole 27 into the sealed case 7 is guided to the discharge pipe 11 side, which is the upper side of the sealed case 7, through the discharge flow path 15 formed in the electric motor 8. It is led to the condenser 3 through.

FIG. 2 shows the inner diameter “D1” of the

cylinder chambers

20a and 20b and the inner diameter of the sealed case 7 under rated conditions using a refrigerant (for example, R410A, R32, carbon dioxide) having a maximum discharge pressure of 3 MPa or more during operation. “H / D1”, when using a 4-pole motor, and when using a 6-pole motor when the total height “H” of the

cylinder chambers

20a and 20b is increased to increase the gas refrigerant discharge capacity. COP (coefficient of performance) ratio (COP when using a 6-pole motor / 4 COP when using a 4-pole motor).

From FIG. 2, in the region of 0.85 <H / D1, that is, in the region where the compression load torque is large, the COP ratio becomes 1 or more, and the 6-pole motor is more effective in suppressing the copper loss and the distance between the iron cores at a large current. It turns out that efficiency becomes high by the iron loss reduction effect by peak magnetic flux reduction. Therefore, in the case of 0.85 × D1 <H, by using a 6-pole motor, it is possible to achieve both a reduction in the diameter of the sealed case 7, an increase in discharge capacity, and an increase in efficiency, and a high breakdown voltage. Thus, it is possible to provide a rotary compressor 2 that is small and light, has a large discharge capacity, and is highly resource-saving.

In FIG. 2, a case where a 6-pole motor is compared with a 4-pole motor is described as an example. However, the same effect can be obtained in a motor having 6 or more poles, for example, an 8-pole motor or a 10-pole motor. Is obtained.

FIG. 3 shows that when 0.85 × D1 <H is satisfied and the distance L1 from the upper end of the stator 14 to the upper inner wall surface of the sealed case 7 is larger than the total height H of the

cylinder chambers

20a and 20b ( The result of measuring the oil discharge amount of the lubricating oil 12 from the discharge pipe 11 with respect to Ad (total cross-sectional area of the discharge flow path 15) / Ac (cross-sectional area of the inner space portion of the sealed case 7) of H <L1) is shown. ing.

The oil discharge amount is expressed as a weight ratio to the circulation amount of the gas refrigerant. When the total height “H” of the

cylinder chambers

20a and 20b is changed without changing the inner diameters of the

cylinder chambers

20a and 20b and the inner diameter of the sealed case 7, the discharge flow path of the electric motor 8 is increased. Since the flow rate of the gas refrigerant at 15 increases, it becomes difficult for the lubricating oil to be separated from the gas refrigerant in the discharge flow path 15, and in particular, it is understood that the amount of discharged oil increases rapidly when Ad / Ac <0.06.

FIG. 4 shows the efficiency ratio of the 6-pole motor 8 with respect to Ad / Ac. The efficiency ratio of the electric motor 8 is expressed as a ratio to the electric motor efficiency when Ad / Ac = 0.13. From FIG. 4, when Ad / Ac> 0.13, the space factor of the field winding 14 b and the cross-sectional area of the permanent magnet 13 b are decreased in order to secure the area of the discharge flow path 15. It can be seen that the efficiency of is significantly reduced. From these facts, by satisfying H <L1 and 0.06 <Ad / Ac <0.13 (relational expression 2), it is possible to reduce the amount of oil discharged while suppressing the deterioration of the motor efficiency.

FIG. 5 shows that T (thickness of the stator core 14a) / when satisfying 0.85 × D1 <H <L1 (relational expression 1) and 0.06 <Ad / Ac <0.13 (relational expression 2). The efficiency ratio of the 6-pole motor 8 with respect to H (the total height of the

cylinder chambers

20a and 20b) is shown. The efficiency ratio of the motor 8 is expressed as a ratio to the motor efficiency at T / H = 1.2. It can be seen that when T / H <1.2, the thickness “T” of the stator core 14a is small with respect to the compression load torque, leading to a reduction in efficiency of the electric motor 8.

FIG. 6 shows the ratio (T / H) of the thickness T of the stator core 14a of the stator 14 to the total height H of the

cylinder chambers

20a and 20b, and the gas in the discharge passage 15 of the electric motor 8 with respect to the compressor theoretical work Wth. The relationship with the ratio of the pressure loss Wd of a refrigerant | coolant is shown. When 1.5 <T / H, Wd / Wth increases rapidly. From these things, 1.2 <T / H <1.5 (relational expression 3) can reduce the pressure loss of the discharge flow path 15 while suppressing the deterioration of the motor efficiency.

Therefore, by satisfying all of the relational expressions 1 to 3, the rotary compression has high pressure resistance, small size and light weight, large discharge capacity, high resource saving, and low oil discharge and high reliability. Machine 2 can be provided.

Further, when reducing the diameter of the sealed case 7 and increasing the discharge capacity, Av / Ac> 0.1 (relational expression 4) and H <L2 (from the lower end of the rotor 13 to the sealed case 7 When the lubricating oil 12 is discharged, a sufficient amount of the lubricating oil 12 can be stored at the bottom of the sealed case 7 by setting the distance to the lower inner wall surface) / 2 (relational expression 5). In addition, it is possible to prevent the oil level of the lubricating oil 12 in the sealed case 7 from being rapidly lowered, and to provide a more reliable rotary compressor 2.
FIG. 7 shows the COP ratio under rated conditions with respect to D2 / H, which is the ratio of the inner diameter D2 of the main bearing 18 and the auxiliary bearing 19 to the total height H of the

cylinder chambers

20a and 20b. The COP ratio is expressed as a ratio to COP when D2 / H = 0.3. In the region of D2 / H <0.3, increasing the distance H increases the distance between the main shafts. However, the rigidity of the rotating shaft 10 becomes insufficient, and the deflection of the rotating shaft 10 becomes excessive, resulting in an increase in COP. Decrease significantly. On the other hand, in the region of D2 / H> 0.4, the diameter of the rotating shaft 10 becomes larger than necessary with respect to the compression load torque, leading to an increase in shaft sliding loss and a decrease in COP. From these facts, by setting 0.3 <D2 / H <0.4 (relational expression 6), it is possible to provide the rotary compressor 2 with even higher efficiency.

As mentioned above, although embodiment of this invention was described, this embodiment is shown as an example and is not intending limiting the range of invention. The novel embodiment can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit 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 1 ... Refrigeration cycle apparatus 2 ... Rotary compressor 3 ... Condenser (radiator)
4 ... Expansion device 5 ... Evaporator (heat absorber)
DESCRIPTION OF SYMBOLS 8 ... Electric motor 9 ... Compression mechanism part 10 ... Rotating shaft 11 ... Discharge pipe 13 ... Rotor 14 ... Stator 14a ... Stator iron core 15 ...

Discharge flow path

16a, 16b ...

Cylinder

18, 19 ...

Bearing

20a, 20b ...

Cylinder chamber

22a, 22b ... Roller

Claims

A sealed case, a motor having 6 or more poles housed in the upper part of the sealed case, and a compression mechanism that is driven through a rotating shaft housed in the lower part of the sealed case and connected to the motor And a discharge pipe provided at an upper portion of the sealed case, and the compression mechanism portion includes two cylinders in which upper and lower ends are closed and a cylinder chamber is formed in the cylinder chamber. The roller fitted to the rotating shaft rotates eccentrically to compress the working fluid, discharge the working fluid compressed in the cylinder chamber into the sealed case, and the electric motor rotates integrally with the rotating shaft. A discharge passage for guiding the working fluid discharged from the cylinder chamber to the discharge pipe side is formed, and the maximum discharge pressure of the working fluid is 3 MPa or more. Rotation to become In the compressor, the inner diameter of the cylinder chamber is D1, the total height of the cylinder chambers of the two cylinders is H, the distance from the upper end of the stator to the upper inner wall surface of the hermetic case is L1, and When the inner cross-sectional area is Ac, the total cross-sectional area of the discharge flow path is Ad, and the thickness of the stator core of the stator is T, the following relational expressions (1) to (3) are all satisfied. Rotary compressor.
(1) 0.85 × D1 <H <L1
(2) 0.06 <Ad / Ac <0.13
(3) 1.2 <T / H <1.5
In a horizontal cross section at the position of the cylinder in the sealed case, Av represents an average cross-sectional area of the space formed outside the cylinder chamber and extending in the vertical direction, from the lower end of the rotor of the motor to the lower part of the sealed case The rotary compressor according to claim 1, wherein the following relational expressions (4) and (5) further hold when the distance to the inner wall surface is L2.
(4) Av / Ac> 0.1
(5) H <L2 / 2
The rotating shaft is pivotally supported by one bearing provided on the end face side of the one cylinder on the electric motor side and the other bearing provided on the end face side of the other cylinder opposite to the electric motor. The rotary compressor according to claim 1 or 2, wherein the following relational expression (6) further holds when the inner diameter of the bearing is D2.
(6) 0.3 <D2 / H <0.4
The rotary compressor according to any one of claims 1 to 3, a radiator connected to the rotary compressor, an expansion device connected to the radiator, the expansion device, and the rotary type A refrigeration cycle apparatus comprising a heat absorber connected between the compressor and the compressor.