WO2018169072A1

WO2018169072A1 - Rotary compressor

Info

Publication number: WO2018169072A1
Application number: PCT/JP2018/010583
Authority: WO
Inventors: 丈雄林; ちひろ遠藤
Original assignee: ダイキン工業株式会社
Priority date: 2017-03-17
Filing date: 2018-03-16
Publication date: 2018-09-20
Also published as: CN110418892B; CN110418892A; EP3597923A1; EP3597923A4; JPWO2018169072A1; ES2953629T3; EP3597923B1; JP6787480B2; MY195534A

Abstract

Provided is a rotary compressor which includes first and second cylinders arranged in the axial direction of a driving shaft, and in which a suction path for supplying a refrigerant, supplied through a suction pipe from an external apparatus, to each of compression chambers is formed. The surface area of a suction path-facing region in the second cylinder is smaller than the surface area of a suction path-facing region in the first cylinder. The difference between the height of the second cylinder in the axial direction and the height in the axial direction of a piston disposed in a compression chamber of the second cylinder is smaller than the difference between the height of the first cylinder in the axial direction and the height in the axial direction of a piston disposed in a compression chamber of the first cylinder (A3-A4 < A1-A2). Therefore, miniaturization of the compressor and inhibition of degradation in compressor efficiency can both be achieved.

Description

Rotary compressor

The present invention relates to a rotary compressor used in, for example, an air conditioner.

Japanese Unexamined Patent Publication No. 2016-118142 discloses a two-cylinder rotary compressor having an upper cylinder and a lower cylinder, in which refrigerant is compressed in a compression chamber formed in each cylinder. An accumulator is attached to the side of the compressor. Two suction pipes are connected to the accumulator. Of the two suction pipes, one is connected to the upper cylinder and the other is connected to the lower cylinder. Refrigerant is supplied from the accumulator to the upper cylinder and the lower cylinder via each suction pipe. A piston having a roller is disposed in a compression chamber formed in each of the upper cylinder and the lower cylinder. The compression chamber is partitioned into a low pressure chamber into which the refrigerant is introduced by a piston and a high pressure chamber into which the refrigerant is compressed.

JP 2016-118142 A

When downsizing a 2-cylinder rotary compressor, it is preferable to reduce the size of external equipment for supplying a refrigerant such as an accumulator. However, when two suction pipes are connected to the accumulator, it is difficult to reduce the size of the accumulator. As a countermeasure, it is conceivable to reduce the size of the accumulator by connecting the two-cylinder rotary compressor and the accumulator with one suction pipe. However, in this case, the suction resistance increases due to the branching of the suction pipe, and the compressor efficiency may decrease.

An object of the present invention is to provide a rotary compressor that can be reduced in size and can suppress a decrease in compressor efficiency.

A rotary compressor according to the present invention is a rotary compressor that houses a compression mechanism and a drive mechanism having a drive shaft that drives the compression mechanism, and the compression mechanism is a cylinder in which a compression chamber is formed. A plurality of cylinders arranged in the axial direction of the drive shaft so that the drive shafts are positioned in the plurality of compression chambers, and arranged at both ends of the cylinders in the axial direction, and partitioning the compression chambers A plurality of end plate members, and a plurality of pistons which are arranged inside each compression chamber and driven by the drive shaft. The plurality of cylinders include a first cylinder and a second cylinder adjacent to the first cylinder via one end plate member, and the rotary compressor is supplied from an external device via a suction pipe. A first passage for supplying the refrigerant to the compression chamber of the first cylinder, and a second passage for branching from the first passage and supplying the refrigerant to the compression chamber of the second cylinder A suction passage is formed. The surface area of the region facing the suction passage in the second cylinder is smaller than the surface area of the region facing the suction passage in the first cylinder. The difference between the height of the second cylinder in the axial direction and the height of the piston arranged in the compression chamber of the second cylinder in the axial direction is about the axial direction of the first cylinder. The difference between the height and the height of the piston disposed in the compression chamber of the first cylinder in the axial direction is smaller.

The external device may be an accumulator or an arbitrary device arranged between the accumulator and the rotary compressor according to the present invention.

In the present invention, the first passage passes through the first cylinder and does not pass through the second cylinder, and the second passage branches from the first passage inside the first cylinder, and It may pass through both the first cylinder and the second cylinder.

In the present invention, the suction pipe may be configured to be insertable into the first cylinder so that a distal end thereof is located in the first cylinder.

In the present invention, the suction pipe is configured to be insertable into the end plate member so that the tip thereof is positioned in the end plate member disposed on the opposite side of the first cylinder from the second cylinder. May have been.

In the present invention, preferably, in the plurality of cylinders, a difference between a height of the cylinder in the axial direction and a height of the piston disposed in the compression chamber of the cylinder in the axial direction is The smaller the surface area of the area facing the suction passage in the cylinder, the smaller.

Furthermore, in the present invention, preferably, for any of the plurality of cylinders, the height of the cylinder in the axial direction is Hc (mm), and the cylinder is disposed inside the compression chamber formed in the cylinder. The height of the piston in the axial direction is Hp (mm), the surface area of the region facing the suction passage in the cylinder is As (mm ² ), and the direction perpendicular to the axial direction of the suction passage in the cylinder is When the length is Ls (mm),
3.9 × 0.0001 ≦ (Hc−Hp) /Hc−1.4×0.0001×As/ (Hc · Ls) ≦ 6.7 × 0.0001
Is satisfied.

In the rotary compressor of the present invention, a first passage for supplying the refrigerant to the compression chamber of the first cylinder, a second passage that is a passage branched from the first passage and supplies the refrigerant to the compression chamber of the second cylinder, Is formed. The surface area of the region facing the suction passage in the second cylinder is smaller than the surface area of the region facing the suction passage in the first cylinder. Therefore, the second cylinder has a smaller temperature drop due to the refrigerant in the vicinity of the region facing the suction passage in the cylinder than the first cylinder. Therefore, the temperature difference between the second cylinder and the piston disposed in the compression chamber of the second cylinder becomes small, and the difference in dimensional change during thermal expansion becomes small. Therefore, in this rotary compressor, the difference between the height of the cylinder and the height of the piston (that is, the axial end surface of the piston and the axial end surface of the end plate member) is compared with the first cylinder. ) Is reduced, oil leakage from the inner peripheral portion of the piston to the compression chamber is reduced, thereby improving volumetric efficiency and illustration efficiency. Therefore, even when two cylinders and an external device are connected by a single suction pipe in order to reduce the size of the compressor, a decrease in compressor efficiency due to an increase in suction resistance can be compensated by an improvement in volumetric efficiency and illustration efficiency. As a result, a decrease in compressor efficiency can be suppressed. That is, it is possible to achieve both downsizing of the compressor and suppression of reduction in compressor efficiency.

It is a figure which shows the rotary compressor which concerns on 1st Embodiment of this invention with an accumulator. It is a top view of the upper cylinder of the rotary compressor shown in FIG. It is a top view of the lower cylinder of the rotary compressor shown in FIG. It is the elements on larger scale of the compression mechanism of the rotary compressor shown in FIG. It is a figure which shows the rotary compressor which concerns on 2nd Embodiment of this invention. It is a top view of the upper cylinder of the rotary compressor shown in FIG. It is a top view of the lower cylinder of the rotary compressor shown in FIG. It is the elements on larger scale of the compression mechanism of the rotary compressor shown in FIG. It is a figure which shows the rotary compressor which concerns on 3rd Embodiment of this invention. It is the elements on larger scale of the compression mechanism of the rotary compressor shown in FIG. It is a graph which shows the experimental result done about a plurality of rotary compressors.

[First Embodiment]
First, the rotary compressor 1 according to the first embodiment will be described with reference to FIGS. As shown in FIG. 1, the compressor 1 according to this embodiment is a two-cylinder rotary compressor, and includes a sealed container 2, a drive mechanism 3 and a compression mechanism 4 accommodated in the sealed container 2. Have. The sealed container 2 is a cylindrical container whose upper and lower ends are closed. An accumulator 5 is attached to the side of the sealed container 2. The accumulator 5 is connected to the compression mechanism 4 by a single suction pipe 6 for introducing a refrigerant. A discharge pipe 7 for discharging the refrigerant compressed by the compression mechanism 4 is provided on the top of the sealed container 2. Lubricating oil is stored at the bottom of the sealed container 2.

The compressor 1 is used by being incorporated in a refrigeration cycle in an air conditioner, for example, and compresses the refrigerant supplied from the suction pipe 6 and discharges it from the discharge pipe 7. In the compressor 1, for example, R32 or R410A is used as the refrigerant. The compressor 1 is installed in the direction shown in FIG. 1, that is, the direction in which the axial direction of the compressor 1 (the same as the axial direction of a drive shaft 3b described later) is the vertical direction.

The drive mechanism 3 is provided to drive the compression mechanism 4, and includes a motor 3a serving as a drive source and a drive shaft 3b attached to the motor 3a. The motor 3a includes a substantially annular stator 3aa fixed to the inner peripheral surface of the hermetic container 2, and a substantially annular rotor 3ab disposed on the radially inner side of the stator 3aa via an air gap. . The rotor 3ab has a magnet (not shown), and the stator 3aa has a coil (not shown).

The drive shaft 3b is fixed to the inner peripheral surface of the rotor 3ab, and rotates together with the rotor 3ab to drive the compression mechanism 4. The drive shaft 3b has

eccentric portions

3c and 3d in a compression chamber 31 and a compression chamber 51, which will be described later (see FIGS. 2A, 2B, and 3). The

eccentric parts

3c and 3d are all formed in a columnar shape, and the central axis thereof is eccentric with respect to the rotation center of the drive shaft 3b.

Pistons

32 and 52 of the compression mechanism 4 are mounted on the

eccentric portions

3c and 3d, respectively.

Also, an oil supply passage (not shown) is formed in the lower half of the drive shaft 3b. The oil supply passage extends in the vertical direction and branches in the radial direction of the drive shaft 3b at several locations. A spiral blade-shaped pump member (not shown) is attached to the lower end of the drive shaft 3b to suck up lubricating oil into the oil supply path as the drive shaft 3b rotates. The lubricating oil sucked up from the lower end of the drive shaft 3b by the pump member is discharged from the side surface of the drive shaft 3b and supplied to each sliding portion of the compression mechanism 4 such as the

compression chambers

31 and 51, for example.

The compression mechanism 4 includes an

upper muffler

10a, 10b, an upper head 20 (end plate member), an upper cylinder 30 (cylinder), a middle plate 40 (end plate member), a lower cylinder 50 (cylinder), and a lower head. 60 (end plate member) and a lower muffler 70 are included. These are arranged in order from top to bottom along the axial direction of the drive shaft 3b.

As shown in FIGS. 1 and 2A, the upper cylinder 30 is a substantially circular plate-like member. A compression chamber 31 which is a circular hole penetrating the upper cylinder 30 in the axial direction of the drive shaft 3b is formed at the center of the upper cylinder 30. A piston 32 is disposed in the compression chamber 31. The piston 32 includes an annular roller 32a and a blade 32b extending radially outward from the outer peripheral surface of the roller 32a. The roller 32 a is mounted in the compression chamber 31 so as to be rotatable relative to the outer peripheral surface of the eccentric portion 3 c.

As shown in FIGS. 2A and 3, the upper cylinder 30 is formed with a transverse passage 30 a extending in the radial direction of the upper cylinder 30 as a suction passage for introducing the refrigerant into the compression chamber 31. The radially inner end of the lateral passage 30 a opens to the compression chamber 31, and the radially outer end of the lateral passage 30 a opens to the outer peripheral surface of the upper cylinder 30. The suction pipe 6 is inserted into the lateral passage 30a from the radially outer end of the lateral passage 30a, and the tip thereof is located near the center of the lateral passage 30a. The upper cylinder 30 is formed with a vertical passage 30b extending vertically downward from the horizontal passage 30a as a suction passage for introducing the refrigerant into the compression chamber 51. The vertical passage 30 b branches from between the radially inner end of the horizontal passage 30 a and the tip position of the suction pipe 6, extends vertically downward, and opens to the lower surface of the upper cylinder 30.

Further, as shown in FIG. 2A, the upper cylinder 30 is formed with a blade accommodating portion 33 having a shape that is recessed radially outward from the peripheral wall surface of the compression chamber 31. A pair of bushes 34 facing the circumferential direction of the upper cylinder 30 are arranged in the blade accommodating portion 33. The pair of bushes 34 has a shape obtained by semi-dividing a substantially cylindrical member. The pair of bushes 34 can swing in the blade accommodating portion 33 with the blade 32b disposed therebetween. Further, the blade 32 b is disposed between the pair of bushes 34 so as to advance and retreat in the radial direction of the upper cylinder 30. The compression chamber 31 is divided into a low pressure chamber and a high pressure chamber by a blade 32b.

As shown in FIG. 1, the upper head 20 is disposed so as to contact the upper end surface of the upper cylinder 30, and the compression chamber 31 is partitioned by closing the upper end of the compression chamber 31. The upper head 20 is a substantially annular member, and the drive shaft 3b is rotatably inserted in the center thereof. The upper head 20 is fixed to the inner peripheral surface of the sealed container 2 by welding or the like.

Upper mufflers

10a and 10b are disposed above the upper head 20. An upper muffler space is formed between the upper head 20 and the upper muffler 10b and between the upper muffler 10a and the upper muffler 10b. The upper muffler space reduces noise caused by the refrigerant discharge.

As shown in FIG. 2A, the upper head 20 is provided with a discharge hole 35 that allows the compression chamber 31 and the upper muffler space to communicate with each other and discharges the refrigerant compressed in the compression chamber 31 to the upper muffler space. The discharge hole 35 is closed by a plate-like discharge valve (not shown). The discharge valve is elastically deformed to open the discharge hole 35 when the pressure in the compression chamber 31 becomes equal to or higher than a predetermined pressure.

The middle plate 40 is a circular plate-like member, and is disposed so as to contact the lower end surface of the upper cylinder 30 and the upper end surface of the lower cylinder 50 as shown in FIG. As shown in FIG. 3, the middle plate 40 closes the lower end of the compression chamber 31 of the upper cylinder 30 to partition the compression chamber 31 and closes the upper end of the compression chamber 51 of the lower cylinder 50 to compress the compression chamber 51. Is partitioned. The middle plate 40 is formed with a vertical passage 40 a connected to the vertical passage 30 b of the upper cylinder 30 as a suction passage for introducing the refrigerant into the compression chamber 51. The vertical passage 40a connects the vertical passage 30b of the upper cylinder 30 and the horizontal passage 50a of the lower cylinder 50 described later.

As shown in FIGS. 1 and 2B, the lower cylinder 50 adjacent to the upper cylinder 30 via the middle plate 40 is a substantially circular plate-like member like the upper cylinder 30. A compression chamber 51, which is a circular hole that penetrates the lower cylinder 50 in the axial direction of the drive shaft 3b, is formed at the center of the lower cylinder 50. A piston 52 is disposed in the compression chamber 51. The piston 52 includes an annular roller 52a and a blade 52b extending radially outward from the outer peripheral surface of the roller 52a. The roller 52a is mounted in the compression chamber 51 so as to be rotatable relative to the outer peripheral surface of the eccentric portion 3d.

As shown in FIGS. 2B and 3, the lower cylinder 50 is formed with a transverse passage 50 a extending in the radial direction of the lower cylinder 50 as a suction passage for introducing the refrigerant into the compression chamber 51. The lateral passage 50a is formed by cutting out the upper surface of the lower cylinder 50. The radially inner end of the lateral passage 50 a opens to the compression chamber 51. The radially outer end of the lateral passage 50a is closed by the wall surface of the lower cylinder 50 in the radial direction and opens upward. As shown in FIG. 3, the radially outer end of the horizontal passage 50a is connected to the vertical passage 40a of the middle plate 40 through the upper opening. A portion of the lateral passage 50 a excluding the opening is closed by the lower surface of the middle plate 40.

Further, as shown in FIG. 2B, the lower cylinder 50 is formed with a blade accommodating portion 53 having a shape recessed from the peripheral wall surface of the compression chamber 51 radially outward. A pair of bushes 54 facing the circumferential direction of the lower cylinder 50 are arranged in the blade accommodating portion 53. The pair of bushes 54 has a shape in which a substantially cylindrical member is divided in half. The pair of bushes 54 can swing in the blade accommodating portion 53 with the blade 52b disposed therebetween. The blade 52b is disposed between the pair of bushes 54 so as to be able to advance and retract in the radial direction of the lower cylinder 50. The compression chamber 51 is divided into a low pressure chamber and a high pressure chamber by a blade 52b.

As shown in FIG. 1, the lower head 60 is arranged so as to contact the lower end surface of the lower cylinder 50, and the compression chamber 51 is partitioned by closing the lower end of the compression chamber 51. The lower head 60 is a substantially annular member, and the drive shaft 3b is rotatably inserted in the center thereof.

A lower muffler 70 is disposed below the lower head 60. A lower muffler space is formed between the lower head 60 and the lower muffler 70. The lower muffler space reduces noise associated with refrigerant discharge.

As shown in FIG. 2B, the lower head 60 is provided with a discharge hole 55 that allows the compression chamber 51 and the lower muffler space to communicate with each other and discharges the refrigerant compressed in the compression chamber 51 to the lower muffler space. The discharge hole 55 is closed by a plate-like discharge valve (not shown). The discharge valve is elastically deformed to open the discharge hole 55 when the pressure in the compression chamber 51 becomes equal to or higher than a predetermined pressure.

The lower muffler space communicates with the upper muffler space through through holes formed in the lower head 60, the lower cylinder 50, the middle plate 40, the upper cylinder 30 and the upper head 20, respectively.

The rotary compressor 1 of the present embodiment includes an upper suction passage (first passage) for supplying refrigerant to the compression chamber 31 of the upper cylinder 30 and a passage branched from the upper suction passage (first passage). A suction passage including a lower suction passage (second passage) for supplying the refrigerant to the compression chamber 51 of the cylinder 50 is formed. In the present embodiment, the upper suction passage is a horizontal passage from the distal end of the suction pipe 6 to the compression chamber 31 among the lateral passages 30a formed in the upper cylinder 30, and passes through the upper cylinder 30 and The lower cylinder 50 is not passed. The lower suction passage includes a vertical passage 30b formed in the upper cylinder 30, a vertical passage 40a formed in the middle plate 40, and a horizontal passage 50a formed in the lower cylinder 50 (see FIG. 3). The lower suction passage passes through both the upper cylinder 30 and the lower cylinder 50.

In other words, the horizontal passage from the front end of the suction pipe 6 to the compression chamber 31 in the horizontal passage 30a (not including from the front end of the suction pipe 6 to the radially outer end of the horizontal passage 30a in the horizontal passage 30a). ) And the vertical passage 30 b form a suction passage in the upper cylinder 30. The lateral passage 50 a forms a suction passage in the lower cylinder 50. In the present embodiment, the surface area of the region facing the suction passage in the lower cylinder 50 is smaller than the surface area of the region facing the suction passage in the upper cylinder 30.

“The surface area of the region facing the suction passage in the cylinder” is the surface area of the inner peripheral surface of the wall forming the suction passage in the cylinder, and the surface area of the wall surface through which the refrigerant sucked from the accumulator 5 passes. Therefore, the surface area of the region facing the suction passage in the upper cylinder 30 is the surface area of the region facing the horizontal passage from the distal end of the suction pipe 6 to the compression chamber 31 in the lateral passage 30a and the vertical passage 30b. The surface area of the region facing the suction passage in the lower cylinder 50 is the surface area of the region facing the lateral passage 50a.

In the lower cylinder 50 where the surface area of the region facing the suction passage is smaller than that of the upper cylinder 30, the temperature drop due to the refrigerant in the vicinity of the region facing the suction passage is smaller than that of the upper cylinder 30. Therefore, the temperature difference between the lower cylinder 50 and the piston 52 disposed in the compression chamber 51 of the lower cylinder 50 is reduced, and the difference in dimensional change during thermal expansion is reduced.

Therefore, in the compressor 1 of this embodiment, as shown in FIG. 3, the difference between the height A3 of the lower cylinder 50 and the height A4 of the piston 52 disposed in the compression chamber 51 of the lower cylinder 50 is It is smaller than the difference between the height A1 of the cylinder 30 and the height A2 of the piston 32 disposed in the compression chamber 31 of the upper cylinder 30 (A3-A4 <A1-A2). Here, the difference between the height A1 of the upper cylinder 30 and the height A2 of the piston 32 and the difference between the height A3 of the lower cylinder 50 and the height A4 of the piston 52 are determined when the compressor 1 is stopped (at room temperature). Time).

The rotary compressor 1 of the present embodiment includes an upper suction passage for supplying refrigerant to the compression chamber 31 of the upper cylinder 30 to which the suction pipe 6 is connected, a passage branched from the upper suction passage, and compression of the lower cylinder 50. A suction passage including a lower suction passage for supplying the refrigerant to the chamber 51 is formed. The surface area of the region facing the suction passage of the lower cylinder 50 is smaller than the surface area of the region facing the suction passage of the upper cylinder 30. Therefore, in the lower cylinder 50, the temperature drop due to the refrigerant near the area facing the suction passage in the cylinder is smaller than that in the upper cylinder 30. Therefore, the temperature difference between the lower cylinder 50 and the piston 52 disposed in the compression chamber 51 of the lower cylinder 50 is reduced, and the difference in dimensional change during thermal expansion is reduced. Therefore, in the lower cylinder 50, as compared with the upper cylinder 30, there is a problem even if the gap between the axial end surface of the piston 52 and the axial end surfaces of the

end plate members

40 and 60 adjacent thereto is reduced. Hateful. Then, by reducing the oil leakage from the inner peripheral portion of the piston to the compression chamber, the volumetric efficiency and the illustration efficiency can be improved, so that the two

cylinders

30, 50 can be reduced in order to reduce the size of the compressor 1. And the accumulator 5 can be connected by a single suction pipe 6, a decrease in compressor efficiency due to an increase in suction resistance can be compensated by an improvement in volumetric efficiency and illustrated efficiency, and a decrease in compressor efficiency can be suppressed. Thus, in this embodiment, it is possible to achieve both downsizing of the compressor 1 and suppression of reduction in compressor efficiency.

In the present embodiment, the upper suction passage (first passage) passes through the upper cylinder 30 and does not pass through the lower cylinder 50, and the lower suction passage (second passage) is located in the upper cylinder 30. It branches from the suction passage and passes through both the upper cylinder 30 and the lower cylinder 50. Thereby, the structure that the surface area of the region facing the suction passage in the lower cylinder 50 is smaller than the surface area of the region facing the suction passage in the upper cylinder 30 can be easily obtained.

Furthermore, in the present embodiment, the suction pipe 6 is configured to be insertable into the upper cylinder 30 so that the tip thereof is located in the upper cylinder 30. As a result, only the linear lateral passage 30a constitutes the refrigerant passage from the tip of the suction pipe 6 to the compression chamber 31 of the upper cylinder 30, and an increase in suction resistance can be suppressed.

[Second Embodiment]
Next, a compressor according to a second embodiment will be described with reference to FIGS. In the compressor 1 of the first embodiment, the case where the suction pipe 6 of the accumulator 5 is configured to be insertable into the upper cylinder 30 has been described. However, the compressor 101 according to the present embodiment has the suction pipe 6 of the accumulator 5 being The second embodiment is different from the first embodiment in that it can be inserted into the upper head 120. In addition, in this embodiment, about the thing which has the structure similar to the said 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted suitably.

The compressor 101 according to the present embodiment accommodates the drive mechanism 3 and the compression mechanism 104. In this compressor 101, as shown in FIGS. 5A and 6, the compressor 101 is disposed on the opposite side of the upper cylinder 130 from the lower cylinder 50 as a suction passage for introducing refrigerant into the compression chamber 31 of the upper cylinder 130. The upper head 120 is formed with a lateral passage 120a extending in the radial direction of the upper head 120 and a longitudinal passage 120b extending vertically downward from the lateral passage 120a. The radially inner end of the horizontal passage 120a is closed by the wall surface of the upper head 120 in the radial direction and opens downward. The radially inner end of the lateral passage 120a is connected to the lateral passage 130a of the upper cylinder 130 through the lower opening. The radially outer end of the lateral passage 120 a opens to the outer peripheral surface of the upper head 120. The suction pipe 6 is inserted from the lateral passage 120a into the lateral passage 120a, and the tip thereof is located near the center of the lateral passage 120a.

The upper cylinder 130 is formed with a lateral passage 130 a extending in the radial direction of the upper cylinder 130 as a suction passage for introducing the refrigerant into the compression chamber 31 of the upper cylinder 130. The lateral passage 130a is formed by cutting out the upper surface of the upper cylinder 130. The radially inner end of the lateral passage 130 a opens to the compression chamber 31. The radially outer end of the lateral passage 130a is closed by the wall surface of the upper cylinder 130 in the radial direction and opens upward. The radially outer end of the horizontal passage 130a is connected to the vertical passage 120b of the upper head 120 through the upper opening. A portion of the lateral passage 130 a except the opening is closed by the lower surface of the upper head 120. The upper cylinder 130 is formed with a vertical passage 130b extending vertically downward from the horizontal passage 130a as a suction passage for introducing the refrigerant into the compression chamber 51 of the lower cylinder 150. The vertical passage 130b branches off from the horizontal passage 130a, extends vertically downward, and opens to the lower surface of the upper cylinder 130.

In the middle plate 40, a vertical passage 40a connected to the vertical passage 130b of the upper cylinder 130 is formed as a suction passage for introducing the refrigerant into the compression chamber 51 of the lower cylinder 50. The vertical passage 40a connects the vertical passage 130b of the upper cylinder 130 and the horizontal passage 50a of the lower cylinder 50 described later.

As shown in FIGS. 5B and 6, the lower cylinder 50 adjacent to the upper cylinder 130 via the middle plate 40 extends in the radial direction of the lower cylinder 50 as a suction passage for introducing the refrigerant into the compression chamber 51. The existing lateral passage 50a is formed. The lateral passage 50a is formed by cutting out the upper surface of the lower cylinder 50. The radially inner end of the lateral passage 50 a opens to the compression chamber 51. The radially outer end of the lateral passage 50a is closed by the wall surface of the lower cylinder 50 in the radial direction and opens upward. As shown in FIG. 6, the radially outer end of the horizontal passage 50a is connected to the vertical passage 40a of the middle plate 40 through the upper opening. A portion of the lateral passage 50 a excluding the opening is closed by the lower surface of the middle plate 40.

The rotary compressor 101 according to the present embodiment includes an upper suction passage (first passage) for supplying refrigerant to the compression chamber 31 of the upper cylinder 130, and a passage branched from the upper suction passage (first passage). A suction passage including a lower suction passage (second passage) for supplying the refrigerant to the compression chamber 51 of the cylinder 50 is formed. In the present embodiment, the upper suction passage includes a horizontal passage and a vertical passage 120b from the front end of the suction pipe 6 to the radially inner end of the horizontal passage 50a in the horizontal passage 120a formed in the upper head 120. , And a lateral passage 130a formed in the upper cylinder 130. The lower suction passage includes a vertical passage 130b formed in the upper cylinder 130, a vertical passage 40a formed in the middle plate 40, and a horizontal passage 50a formed in the lower cylinder 50 (see FIG. 6).

In other words, the horizontal passage 130a and the vertical passage 130b form a suction passage in the upper cylinder 130. The lateral passage 50 a forms a suction passage in the lower cylinder 50. In the present embodiment, the surface area of the region facing the suction passage in the lower cylinder 50 is smaller than the surface area of the region facing the suction passage in the upper cylinder 130.

In the lower cylinder 50 where the surface area of the region facing the suction passage is smaller than that of the upper cylinder 130, the temperature drop due to the refrigerant near the region facing the suction passage is smaller than that of the upper cylinder 130. Therefore, the temperature difference between the lower cylinder 50 and the piston 52 disposed in the compression chamber 51 of the lower cylinder 50 is reduced, and the difference in dimensional change during thermal expansion is reduced.

Therefore, in the compressor 101 of this embodiment, as shown in FIG. 6, the difference between the height A3 of the lower cylinder 50 and the height A4 of the piston 52 disposed in the compression chamber 51 of the lower cylinder 50 is It is smaller than the difference between the height A1 of the cylinder 130 and the height A2 of the piston 32 disposed in the compression chamber 31 of the upper cylinder 130 (A3-A4 <A1-A2). Here, the difference between the height A1 of the upper cylinder 130 and the height A2 of the piston 32 and the difference between the height A3 of the lower cylinder 50 and the height A4 of the piston 52 are determined when the compressor 101 is stopped (at room temperature). Time).

In the rotary compressor 101 of the present embodiment, an upper suction passage that supplies refrigerant to the compression chamber 31 of the upper cylinder 130 and a passage branched from the upper suction passage and supplies refrigerant to the compression chamber 51 of the lower cylinder 50. A suction passage including a lower suction passage is formed. The surface area of the region facing the suction passage of the lower cylinder 50 is smaller than the surface area of the region facing the suction passage of the upper cylinder 130. Therefore, in the lower cylinder 50, the temperature drop due to the refrigerant near the area facing the suction passage in the cylinder is smaller than that in the upper cylinder 130. Therefore, the temperature difference between the lower cylinder 50 and the piston 52 disposed in the compression chamber 51 of the lower cylinder 50 is reduced, and the difference in dimensional change during thermal expansion is reduced. Therefore, in the lower cylinder 50, as compared with the upper cylinder 130, there is a problem even if the gap between the axial end surface of the piston 52 and the axial end surfaces of the

end plate members

40 and 60 adjacent thereto is reduced. Hateful. Then, by reducing the oil leakage from the piston inner peripheral portion to the compression chamber, the volumetric efficiency and the illustration efficiency can be improved, so that the two

cylinders

130, 50 can be reduced in order to reduce the size of the compressor 101. And the accumulator 5 can be connected by a single suction pipe 6, a decrease in compressor efficiency due to an increase in suction resistance can be compensated by an improvement in volumetric efficiency and illustrated efficiency, and a decrease in compressor efficiency can be suppressed. In this way, in the present embodiment, it is possible to achieve both downsizing of the compressor 101 and suppression of reduction in compressor efficiency.

In the present embodiment, the upper suction passage (first passage) passes through the upper cylinder 130 and does not pass through the lower cylinder 50, and the lower suction passage (second passage) is located in the upper cylinder 130. It branches from the suction passage and passes through both the upper cylinder 130 and the lower cylinder 50. Thus, a configuration in which the surface area of the region facing the suction passage in the lower cylinder 50 is smaller than the surface area of the region facing the suction passage in the upper cylinder 130 can be easily obtained.

Further, in the present embodiment, the suction pipe 6 has an upper head 120 such that the tip of the suction pipe 6 is positioned in the upper head 120 which is an end plate member disposed on the opposite side of the upper cylinder 130 from the lower cylinder 50. It is configured to be insertable. As a result, the upper suction passage has one portion where the traveling direction of the refrigerant changes from the vertical to the horizontal in the upper cylinder 130, and the lower suction passage has the traveling direction of the refrigerant in the lower cylinder 50 from the vertical to the horizontal. It will have one point that changes to. That is, it is difficult for a large difference in suction resistance to occur between the upper suction passage and the lower suction passage.

[Third Embodiment]
Next, the compressor concerning 3rd Embodiment is demonstrated, referring FIG.7 and FIG.8. The compressor 1 according to the third embodiment is different from the first embodiment in that the suction pipe 6 of the accumulator 5 is configured to be inserted into the lower cylinder 250. In addition, in this embodiment, about the thing which has the structure similar to the said 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted suitably.

The compressor 201 according to the present embodiment accommodates the drive mechanism 3 and the compression mechanism 204. As shown in FIGS. 7 and 8, as a suction passage for introducing the refrigerant into the compression chamber 51 of the lower cylinder 250, a lateral passage 250 a extending in the radial direction of the lower cylinder 250 is formed in the lower cylinder 250. ing. The radially inner end of the lateral passage 250 a opens into the compression chamber 51, and the radially outer end of the lateral passage 250 a opens at the outer peripheral surface of the lower cylinder 250. The suction pipe 6 is inserted into the lateral passage 250a from the radially outer end of the lateral passage 250a, and the tip thereof is located near the center of the lateral passage 250a. The lower cylinder 250 is formed with a vertical passage 250b extending vertically upward from the horizontal passage 250a as a suction passage for introducing the refrigerant into the compression chamber 31 of the upper cylinder 230. The vertical passage 250 b branches from the radial inner end of the horizontal passage 250 a and the tip position of the suction pipe 6, extends vertically upward, and opens on the upper surface of the lower cylinder 250. Further, the lower cylinder 250 is formed with a vertical passage 250c extending vertically downward from the horizontal passage 250a. The vertical passage 250c branches from the radially inner end of the horizontal passage 250a and the tip position of the suction pipe 6 (a position overlapping the vertical passage 250b vertically) and extends vertically downward to the lower surface of the lower cylinder 250. Is open. This opening is closed by the lower head 60.

The middle plate 240 is formed with a vertical passage 240 a connected to the vertical passage 250 b of the lower cylinder 250 as a suction passage for introducing the refrigerant into the compression chamber 31. The vertical passage 240a connects the vertical passage 250b of the lower cylinder 250 and the horizontal passage 230a of the upper cylinder 230 described later.

In the upper cylinder 230 adjacent to the lower cylinder 250 via the middle plate 240, a lateral passage 230a extending in the radial direction of the upper cylinder 230 is formed as a suction passage for introducing the refrigerant into the compression chamber 31. . The lateral passage 230a is formed by cutting out the lower surface of the upper cylinder 230. The radially inner end of the lateral passage 230 a opens to the compression chamber 31. The radially outer end of the lateral passage 230a is closed by the wall surface of the upper cylinder 230 in the radial direction and opens downward. The radially outer end of the lateral passage 230a is connected to the longitudinal passage 240a of the middle plate 240 through the lower opening. A portion of the lateral passage 230 a excluding the opening is closed by the upper surface of the middle plate 240.

The compressor 201 of the present embodiment includes a lower suction passage (first passage) for supplying refrigerant to the compression chamber 51 of the lower cylinder 250, and a passage branched from the lower suction passage (first passage) and the upper cylinder. A suction passage including an upper suction passage (second passage) for supplying the refrigerant to the compression chamber 31 of 230 is formed. In the present embodiment, the lower suction passage is a horizontal passage from the front end of the suction pipe 6 to the compression chamber 51 in the lateral passage 250a formed in the lower cylinder 250, and the upper suction passage is the lower cylinder. The vertical passage 250 b is formed in the vertical plate 250 b, the vertical passage 240 a is formed in the middle plate 240, and the horizontal passage 230 a is formed in the upper cylinder 230.

In other words, the horizontal passage from the front end of the suction pipe 6 to the compression chamber 51 in the horizontal passage 250a (not including from the front end of the suction pipe 6 to the radially outer end of the horizontal passage 250a in the horizontal passage 250a). ) And the vertical passage 250 b form a suction passage in the lower cylinder 250. The lateral passage 230 a forms a suction passage in the upper cylinder 230. In the present embodiment, the surface area of the region facing the suction passage in the upper cylinder 230 is smaller than the surface area of the region facing the suction passage in the lower cylinder 250.

In the upper cylinder 230 in which the surface area of the region facing the suction passage is smaller than that of the lower cylinder 250, the temperature drop due to the refrigerant in the vicinity of the region facing the suction passage is smaller than that of the lower cylinder 250. Therefore, the temperature difference between the upper cylinder 230 and the piston 32 disposed in the compression chamber 31 of the upper cylinder 230 is reduced, and the difference in dimensional change during thermal expansion is reduced.

Therefore, in the compressor 201 of this embodiment, as shown in FIG. 8, the difference between the height A1 of the upper cylinder 230 and the height A2 of the piston 32 disposed in the compression chamber 31 of the upper cylinder 230 is lower. It is smaller than the difference between the height A3 of the cylinder 250 and the height A4 of the piston 52 disposed in the compression chamber 51 of the lower cylinder 250 (A1-A2 <A3-A4). Here, the difference between the height A3 of the lower cylinder 250 and the height A4 of the piston 52 and the difference between the height A1 of the upper cylinder 230 and the height A2 of the piston 32 are determined when the compressor 201 is stopped (at room temperature). Time).

In the rotary compressor 201 of the present embodiment, a refrigerant is supplied to the compression chamber 31 of the upper cylinder 230, which is a lower intake passage that supplies refrigerant to the compression chamber 51 of the lower cylinder 250 and a passage branched from the lower intake passage. A suction passage including an upper suction passage is formed. The surface area of the region facing the suction passage of the upper cylinder 230 is smaller than the surface area of the region facing the suction passage of the lower cylinder 250. Therefore, in the upper cylinder 230, the temperature drop due to the refrigerant in the vicinity of the region facing the suction passage in the cylinder is smaller than in the lower cylinder 250. Therefore, the temperature difference between the upper cylinder 230 and the piston 32 disposed in the compression chamber 31 of the upper cylinder 230 is reduced, and the difference in dimensional change during thermal expansion is reduced. Therefore, in the upper cylinder 230, as compared with the lower cylinder 250, there is a problem even if the gap between the axial end surface of the piston 32 and the axial end surfaces of the

end plate members

20 and 240 adjacent thereto is reduced. Hateful. Then, by reducing the oil leakage from the piston inner peripheral portion to the compression chamber, the volumetric efficiency and the illustration efficiency can be improved. Therefore, in order to reduce the size of the compressor 201, the two

cylinders

230 and 250 are reduced. And the accumulator 5 can be connected by a single suction pipe 6, a decrease in compressor efficiency due to an increase in suction resistance can be compensated by an improvement in volumetric efficiency and illustrated efficiency, and a decrease in compressor efficiency can be suppressed. In this way, in the present embodiment, it is possible to achieve both reduction in size of the compressor 201 and suppression of reduction in compressor efficiency.

Further, in the present embodiment, the lower suction passage (first passage) passes through the lower cylinder 250 and does not pass through the upper cylinder 230, and the upper suction passage (second passage) is located inside the lower cylinder 250. It branches from the suction passage and passes through both the lower cylinder 250 and the upper cylinder 230. Thereby, the configuration in which the surface area of the region facing the suction passage in the upper cylinder 230 is smaller than the surface area of the region facing the suction passage in the lower cylinder 250 can be easily obtained.

Furthermore, in the present embodiment, the suction pipe 6 is configured to be insertable into the lower cylinder 250 so that the tip thereof is located in the lower cylinder 250. Thereby, only the linear lateral passage 250a constitutes the refrigerant passage from the tip of the suction pipe 6 to the compression chamber 51 of the lower cylinder 250, and an increase in suction resistance can be suppressed.

[Verification test with actual machine]
Here, the results of tests performed on a plurality of rotary compressors will be described. As described above, in the rotary compressor according to the present invention, the second cylinder reduces the difference between the height of the cylinder and the height of the piston as compared with the first cylinder, so that the compression chamber extends from the piston inner peripheral portion. This reduces the oil leakage to the compressor, thereby improving the compressor efficiency. As the difference between the height of the cylinder and the height of the piston is smaller, the compressor efficiency can be improved. On the other hand, seizure due to sliding friction between the piston and the end plate member is likely to occur, and the reliability is lowered. Conversely, as the difference between the cylinder height and the piston height increases, seizure due to sliding friction between the piston and the end plate member is less likely to occur, and the reliability is improved while the compressor efficiency decreases. End up.

Therefore, the present inventors conducted a verification test using a plurality of rotary compressors (including several types) to determine whether acceptable compressor efficiency can be obtained while ensuring reliability. In this test, the height Hc (mm) in the drive shaft axial direction of the cylinder, the height Hp (mm) in the axial direction of the piston arranged inside the compression chamber formed in the cylinder, the suction passage in the cylinder The surface area As (mm ² ) of the facing region and the length Ls (mm) of the suction passage in the cylinder were used as variables. The length Ls is the length of the suction passage in a plane orthogonal to the drive shaft axis direction, and is the length in the radial direction of the cylinder in the above-described embodiment. Examples of the length Ls are shown as L1 and L2 in FIGS.

For each compressor with the four variables Hc, Hp, As, and Ls changed, whether seizure occurs due to sliding friction between the piston and the end plate member, and whether acceptable compressor efficiency is obtained. Evaluated. FIG. 9 is a graph depicting the results.

In FIG. 9, the parameter on the vertical axis is (the difference in height between the cylinder and the piston (Hc−Hp) / cylinder height Hc), which represents the rate of change of the cylinder height as the temperature changes. When the temperature near the area facing the suction passage in the cylinder is reduced by the refrigerant, the cylinder is thermally contracted, and the height difference (Hc−Hp) from the piston is reduced. When this becomes zero, the piston is sandwiched between the end plate members and seizure occurs, which may damage the compressor. As the numerical value on the vertical axis increases, seizure hardly occurs.

The parameter on the horizontal axis is (surface area As of the area facing the suction passage in the cylinder / cylinder height Hp × length Ls in the extending direction of the suction passage), and represents the ease of temperature change of the cylinder. . That is, the larger the surface area of the area facing the suction passage in the cylinder, the more the cylinder is cooled by the refrigerant and the temperature is likely to decrease. On the other hand, as the cylinder height and the length in the extending direction of the suction passage are larger, the temperature of the cylinder is less likely to decrease due to the increase in heat capacity. As described above, the temperature in the vicinity of the region facing the suction passage in the cylinder varies according to the balance between the surface area As, the cylinder height Hp, and the length Ls in the extending direction of the suction passage. .

In FIG. 9, an approximate line A represented as a straight line is a limit line indicating a lower limit of performance in terms of compressor efficiency. That is, an acceptable compressor efficiency is obtained in the region below the approximate line A. The approximate line B expressed as a straight line having the same inclination as the approximate line A is a limit line that is acceptable in terms of reliability (no seizure occurs). That is, the region where the seizure does not occur is above the approximate line B. here,
The approximate line A is
(Hc−Hp) /Hc=1.4×0.0001×As/ (Hc · Ls) + 6.7 × 0.0001
And
The approximate line B is
(Hc−Hp) /Hc=1.4×0.0001×As/ (Hc · Ls) + 3.9 × 0.0001
It is.

Therefore, the values of the four variables Hc, Hp, As, and Ls are expressed by the relational expression 3.9 × 0.0001 ≦ (Hc−Hp) /Hc−1.4×0.0001×As/ (Hc · Ls). ≦ 6.7 × 0.0001
By setting it as the value which satisfy | fills, the compressor which satisfy | fills both compressor efficiency and reliability can be obtained.

[Modification]
In the first embodiment described above, the first cylinder may be the lower cylinder 50 and the second cylinder may be the upper cylinder 30. That is, the surface area of the region facing the suction passage in the upper cylinder 30 may be smaller than the surface area of the region facing the suction passage in the lower cylinder 50. Similarly, in the second embodiment, the first cylinder may be the lower cylinder 50 and the second cylinder may be the upper cylinder 130. That is, the surface area of the region facing the suction passage in the upper cylinder 130 may be smaller than the surface area of the region facing the suction passage in the lower cylinder 50. In the third embodiment, the first cylinder may be the upper cylinder 230 and the second cylinder may be the lower cylinder 250. That is, the surface area of the region facing the suction passage in the lower cylinder 250 may be smaller than the surface area of the region facing the suction passage in the upper cylinder 230.

The configuration (arrangement, cross-sectional shape, etc.) of the suction passage is not limited to that shown in the first to third embodiments, and may be changed as appropriate. As an example, in the first to third embodiments, the example in which the

lateral passages

30a, 50a; 130a; 230a, 250a extend in the radial direction of the cylinder has been described, but these lateral passages communicate with the compression chamber. As long as it is, it may extend in any direction within a plane perpendicular to the axial direction of the drive shaft.

In the first to third embodiments, the accumulator fixed to the rotary compressor according to the present invention is exemplified as the external device, but is not limited to this. The external device may be, for example, an accumulator that is not fixed to the rotary compressor according to the present invention, or a device (evaporator or the like) other than the accumulator.

In the first to third embodiments, the piston roller and the blade are integrally formed, but the roller and the blade may be formed separately.

In the first to third embodiments, a two-cylinder rotary compressor having an upper cylinder and a lower cylinder has been described. However, a rotary compressor having three or more cylinders may be used. In this case, in three or more cylinders, the difference between the height in the drive shaft axial direction of the cylinder and the height in the axial direction of the piston disposed in the compression chamber of the cylinder is a region facing the suction passage in the cylinder. The smaller the surface area, the smaller.

As mentioned above, although embodiment of this invention was described based on drawing, it should be thought that a specific structure is not limited to these embodiment. The scope of the present invention is shown not by the above description of the embodiment but by the scope of the claims, and further includes meanings equivalent to the scope of the claims and all modifications within the scope.

DESCRIPTION OF SYMBOLS 1; 201 Rotary compressor 3 Drive mechanism 4; 204 Compression mechanism 20; 120 Upper head (end plate member)
30; 130; 230 Upper cylinder (cylinder, first cylinder)
31, 51

Compression chamber

32, 52 Piston 40; 240 Middle plate (end plate member)
50; 250 Lower cylinder (cylinder, second cylinder)
60 Lower head (end plate member)

Claims

A rotary compressor containing a compression mechanism and a drive mechanism having a drive shaft for driving the compression mechanism,
The compression mechanism is
A plurality of cylinders arranged in the axial direction of the drive shaft so that the drive shafts are positioned in the plurality of compression chambers, respectively.
A plurality of end plate members disposed at both ends of each cylinder in the axial direction and defining the compression chamber;
A plurality of pistons disposed inside each compression chamber and driven by the drive shaft;
The plurality of cylinders include a first cylinder and a second cylinder adjacent to the first cylinder via one end plate member,
The rotary compressor includes a first passage for supplying a refrigerant supplied from an external device through a suction pipe to the compression chamber of the first cylinder, and a passage branched from the first passage. A suction passage including a second passage for supplying a refrigerant to the compression chamber of two cylinders is formed;
The surface area of the region facing the suction passage in the second cylinder is smaller than the surface area of the region facing the suction passage in the first cylinder,
The difference between the height of the second cylinder in the axial direction and the height of the piston arranged in the compression chamber of the second cylinder in the axial direction is the height of the first cylinder in the axial direction. The rotary compressor characterized by being smaller than the difference with the height about the said axial direction of the said piston arrange | positioned at the said compression chamber of a said 1st cylinder.
The first passage passes through the first cylinder and does not pass through the second cylinder;
2. The rotary compressor according to claim 1, wherein the second passage is branched from the first passage inside the first cylinder and passes through both the first cylinder and the second cylinder. .
3. The rotary compressor according to claim 2, wherein the suction pipe is configured to be inserted into the first cylinder so that a tip thereof is located in the first cylinder.
The suction pipe is configured to be insertable into the end plate member so that a tip of the suction pipe is located in the end plate member disposed on the opposite side of the first cylinder from the second cylinder. The rotary compressor according to claim 2.
In the plurality of cylinders, a difference between a height of the cylinder in the axial direction and a height of the piston arranged in the compression chamber of the cylinder in the axial direction is a region facing the suction passage in the cylinder. The rotary compressor according to any one of claims 1 to 4, wherein the rotary compressor has a smaller surface area.
For any of the plurality of cylinders, the height of the cylinder in the axial direction is Hc (mm), and the height of the piston disposed in the compression chamber formed in the cylinder in the axial direction. Hp (mm), the surface area of the cylinder facing the suction passage is As (mm 2 ), and the length of the cylinder in the direction perpendicular to the axial direction of the suction passage is Ls (mm). sometimes,
3.9 × 0.0001 ≦ (Hc−Hp) /Hc−1.4×0.0001×As/ (Hc · Ls) ≦ 6.7 × 0.0001
The rotary compressor according to any one of claims 1 to 5, wherein: