CN104074764A - rotary compressor - Google Patents

Abstract

The invention relates to a rotary compressor (100). A motor (2) and a compression mechanism (3) driven by a crankshaft (4) via the motor (2) are disposed in a sealed container (1). A first cylinder (8) and a second cylinder (9) are disposed in the compression mechanism (3), and are independently connected with suction pipes (43,44)of coolant gas. The cylinders (8,9) are respectively provided with cylindrical cylinder chambers (30,31), which are provided with suction ports (50,51) in a radially-penetrating manner. The rotary compressor is provided with connecting suction ports (50,51) and connecting pipes (60,61) of the suction pipes (43,44). The central shafts of the suction port side connecting parts (60a,61a) of the connecting pipes (60,61) are eccentric toward the adjacent direction by comparing with the central shaft of the suction pipe side connection parts (60b,61b).

Description

rotary compressor

technical field

The present invention relates to a rotary compressor for compressing refrigerant gas used in a refrigerating cycle of a refrigerating and air-conditioning apparatus such as an air conditioner or a refrigerator.

Background technique

Conventionally, in refrigerating and air-conditioning apparatuses such as air conditioners and refrigerators, rotary compressors having a plurality of cylinders are used. Furthermore, an accumulator storing refrigerant is connected to the suction side of the rotary compressor, and the refrigerant from the accumulator is sucked into the suction port of each cylinder through each suction pipe provided with the same number as the cylinders. The accumulator has a structure in which the container and the respective suction pipes are fixed, and the ends of the respective suction pipes of the accumulator are connected to respective connection portions provided on the surface of the airtight container of the rotary compressor.

Moreover, in such a rotary compressor, when the suction pipes are close to each other, that is, when the intervals between the connecting parts provided in the airtight container are close, the welding workability will be reduced, so as not to hinder the welding work. sexual structure. Therefore, a rotary compressor has been proposed in which, in an airtight container, the connecting parts arranged at different height positions are shifted along the circumferential direction of the airtight container, thereby, compared with the case of adopting the same position in the circumferential direction, the The distance between the connection parts is increased (for example, refer to Patent Document 1). In this rotary compressor, by increasing the distance between the connecting parts, the distance between the respective suction pipes can be widened, and the welding workability can be improved.

In addition, as another technique for improving welding workability, there is a rotary compressor in which the suction port of each cylinder is connected to each suction pipe through a connecting pipe (for example, refer to Patent Document 2). Assuming that the connection pipe is not used, the suction pipes are inserted into the connection portions of the airtight container and connected to the suction ports of the further cylinders. However, when connecting pipes are used, the length of the suction pipe itself can be correspondingly shortened, so that the welding work can be improved compared with the case where each suction pipe is directly inserted into the inner side of the airtight container and connected to each suction port of each cylinder. sex.

[Prior Art Literature]

【Patent Literature】

[Patent Document 1] Japanese Patent Application Laid-Open No. 9-079161 (page 3, Figures 1 to 3)

[Patent Document 2] Japanese Patent Laid-Open No. 2003-214370 (page 4, Fig. 1)

In the rotary compressor described in Patent Document 1, the positions of the connection parts provided in the airtight container are shifted in the circumferential direction, so the suction pipes are shifted from each other rather than overlapping positions when viewed from a plane. Accordingly, each time each suction pipe is connected to each suction port of each cylinder, the connecting portion of the airtight container is inserted obliquely from different directions with respect to the airtight container. The suction pipes are fixed to the container of the accumulator as described above, so there is a problem that it is difficult to simultaneously insert the suction pipes into the connecting portion of the airtight container from an oblique direction while holding the container.

In addition, the rotary compressor described in Patent Document 1 does not use a connecting pipe as in Patent Document 2, but has a structure in which a suction pipe is directly connected to a suction port, and this also becomes a factor of lowering workability.

In order to improve such a decrease in workability, it is conceivable to increase the hole diameter and suction port diameter of each connection part of the airtight container to easily insert each suction pipe into each connection part and each suction port. However, in this case, the gaps between the suction pipes and the connection parts, and the gaps between the suction pipes and the suction ports become large, and problems such as welding failure and sealing failure newly arise.

Incidentally, in a rotary compressor having a plurality of cylinders, a main bearing and a sub-bearing which rotatably support a crankshaft are arranged so as to sandwich the plurality of cylinders from above and below. The main bearing and the sub-bearing serve as support points for the compressed gas load, and as the distance between the main bearing and the sub-bearing becomes longer, the crankshaft tends to deflect. In other words, as the axial distance between the cylinders becomes longer, the crankshaft becomes more likely to deflect.

When the deflection of the crankshaft 4 increases, the inclination of the crankshaft with respect to the main bearing or the sub bearing increases, and a decrease in bearing reliability due to one-sided contact occurs. In order to prevent such bending of the crankshaft, it is sufficient to increase the rigidity by increasing the shaft diameter. However, when the shaft diameter of the crankshaft is increased, the shaft sliding loss increases accordingly, leading to a reduction in the efficiency of the compressor. Therefore, in a rotary compressor having a plurality of cylinders, a structure capable of reducing the axial distance between the cylinders is required.

But, in order to reduce the axial interval of each cylinder, it is necessary to reduce the interval of each connecting part of the airtight container, so when considering the workability of welding each suction pipe to the suction port of each cylinder, it is necessary to reduce the axial interval of each cylinder. limit.

Contents of the invention

The present invention was developed to solve the above-mentioned problems, and an object of the present invention is to obtain a high-efficiency rotary compressor capable of reducing the axial distance of each cylinder without interfering with the welding workability of the airtight container and the suction pipe.

The rotary compressor of the present invention has a motor and a compression mechanism driven by the motor via a crankshaft in an airtight container, and suction pipes for refrigerant gas are independently connected to a plurality of cylinders provided in the compression mechanism, wherein the plurality of cylinders are respectively It has a cylindrical cylinder chamber, and a suction port is formed radially through the cylinder chamber. The rotary compressor has a connecting pipe connecting the suction port and the suction pipe. The connecting pipe has a suction port side connection part and a suction pipe side connection part, For each of the two connection pipes connected to at least two adjacent cylinders among the plurality of cylinders, the central axis of the suction port side connection part is eccentric to the direction closer to each other than the central axis of the suction pipe side connection part.

According to the present invention, a high-efficiency rotary compressor can be obtained, and the axial distance between the cylinders can be reduced without hindering the workability of welding the airtight container and the suction pipe.

Description of drawings

Fig. 1 is a longitudinal sectional view of a rotary compressor 100 according to Embodiment 1 of the present invention.

FIG. 2 is an enlarged view of the compression mechanism 3 of FIG. 1 .

FIG. 3 is a cross-sectional view of the first cylinder 8 of FIG. 1 .

Fig. 4 is a comparison diagram between the rotary compressor 100 according to Embodiment 1 of the present invention and a conventional one.

Fig. 5 is a diagram showing a cross-sectional shape of the suction port 50 of the rotary compressor 100 according to Embodiment 1 of the present invention.

FIG. 6 is an explanatory view of the cross-sectional shape of the flow path of the connection pipe 60 in FIG. 1 , and is a view that combines a front sectional view, a left side sectional view, and a right sectional view.

FIG. 7 is an explanatory diagram of a modification example of the cross-sectional shape of the flow path of the connecting pipe 60 in FIG. 1 , and is a diagram that includes a cross-sectional view viewed from the front, a cross-sectional view viewed from the left side, and a cross-sectional view viewed from the right side.

Fig. 8 is an enlarged sectional view taken along line B-B of Fig. 3 .

9 shows that the suction pipe side connection part 60b is circular and the suction port side connection part 60a is a non-circular shape. The explanatory drawing of the same connecting pipe 60A is a cross-sectional view viewed from the front, a view showing the cross-sectional shape of the flow path viewed from the left, and a view showing the cross-sectional shape of the flow path viewed from the right.

10 is a cross-sectional view of the first cylinder 8 of the rotary compressor 100 according to Embodiment 1 of the present invention, and is an explanatory view of the compression process angle θ determined by the suction port edge 50b and the discharge port edge 70a.

Fig. 11 is a sectional view of essential parts of a rotary compressor according to Embodiment 2 of the present invention.

FIG. 12 is a comparison example in which the cross-sectional shape of the suction port-side connecting portion 60a of the connecting pipe 60 is a long hole without a convex shape as in Embodiment 1, and shows that the connecting pipe 60 is pressed into the suction port whose cross-sectional shape is a long hole. A schematic diagram of the direction of the internal stress of the connecting pipe 60 at 50.

FIG. 13 is a schematic diagram showing a state in which the connecting pipe 60 is deformed by the internal stress in FIG. 12 .

Explanation of reference signs

1 airtight container, 1a main body part, 1b upper plate container, 1d connection part, 1e connection part, 2 electric motor, 2a stator, 2b rotor, 3 compression mechanism, 4 crankshaft, 4a main shaft part, 4b counter shaft part, 4c eccentric shaft part , 4d eccentric shaft part, 4e intermediate shaft part, 5 middle partition, 5a first blade, 6 main bearing, 7 auxiliary bearing, 8 first cylinder, 8a inner periphery, 8b blade groove, 9 second cylinder, 11a first Piston, 11b second piston, 11c outer periphery, 25 compressor discharge pipe, 26 glass terminal, 27 lead wire, 30 first cylinder chamber, 30a suction chamber, 30b compression chamber, 31 second cylinder chamber, 40 accumulator, 41 container, 42 Inlet pipe, 43 Suction pipe, 44 Suction pipe, 50 Suction port, 50b Suction port edge, 51 Suction port, 60 Connection pipe, 60A Connection pipe, 60a Suction port side connection, 60b Suction pipe side connection, 60c Long side 60d curved part, 60e convex shape, 61 connecting pipe, 61a suction port side connecting part, 61b suction pipe side connecting part, 70 discharge port, 70a discharge port edge, 100 rotary compressor.

Detailed ways

Embodiment 1

Fig. 1 is a longitudinal sectional view of a rotary compressor 100 according to Embodiment 1 of the present invention. FIG. 2 is an enlarged view of the compression mechanism 3 of FIG. 1 . FIG. 3 is a cross-sectional view of the first cylinder 8 of FIG. 1 . The drawings show a two-cylinder rotary compressor with two cylinders, but the rotary compressor of the present invention is not limited to a two-cylinder structure, and may also adopt a multi-cylinder structure.

The rotary compressor 100 includes a motor 2 and a compression mechanism 3 driven by the motor 2 via a crankshaft 4 in a sealed container 1 .

The airtight container 1 has a structure in which the upper container 1b and the main body 1a are integrated by welding. Refrigerator oil (not shown) for lubricating the sliding portion of the compression mechanism 3 is stored in the bottom of the airtight container 1 . In addition, on the upper portion of the airtight container 1 , a compressor discharge pipe 25 is provided so as to communicate with the inner space of the airtight container 1 . In addition, connection portions 1d and 1e respectively independently connected to suction pipes 43 and 44 of the accumulator 40 described later are welded to the main body portion 1a of the airtight container 1 .

The motor 2 is variable in rotation speed by, for example, frequency conversion control, and has a stator 2a and a rotor 2b. The motor 2 is usually a brushless DC motor using permanent magnets for the rotor 2b. However, there are also cases where induction motors are used. The stator 2a is formed in a substantially cylindrical shape, and its outer peripheral portion is fixed to the airtight container 1 by, for example, thermal fitting.

The stator 2 a has a structure in which a coil is wound, and electric power is supplied to the stator 2 a from an external power source (not shown) through glass terminals 26 and lead wires 27 . The rotor 2b has a substantially cylindrical shape, and is disposed on the inner peripheral portion of the stator 2a at a predetermined interval from the inner peripheral surface of the stator 2a. A crankshaft 4 is fixed to the rotor 2 b , and the electric motor 2 and the compression mechanism 3 are connected via the crankshaft 4 . That is, the electric motor 2 rotates, whereby rotational power is transmitted to the compression mechanism 3 via the crankshaft 4 .

As shown in FIG. 2, the crankshaft 4 is composed of the following parts: a main shaft portion 4a constituting the upper portion of the crankshaft 4; a sub shaft portion 4b constituting a lower portion of the crank shaft 4; The eccentric shaft parts 4c, 4d and the intermediate shaft part 4e. Here, the central axis of the eccentric shaft portion 4c is eccentric by a predetermined distance from the central axes of the main shaft portion 4a and the sub shaft portion 4b, and the eccentric shaft portion 4c is arranged in the first cylinder chamber 30 of the first cylinder 8 described later. The central axis of the eccentric shaft portion 4d is eccentric by a predetermined distance from the central axes of the main shaft portion 4a and the sub shaft portion 4b, and the eccentric shaft portion 4d is arranged in the second cylinder chamber 31 of the second cylinder 9 described later.

In addition, the eccentric shaft portion 4c and the eccentric shaft portion 4d are provided with a phase shift of 180 degrees. The eccentric shaft portion 4c and the eccentric shaft portion 4d are connected by the intermediate shaft portion 4e. In addition, the intermediate shaft portion 4e is disposed in a through hole of the intermediate partition plate 5 described later. In the crankshaft 4 configured in this way, the main shaft portion 4 a is rotatably supported by the main bearing 6 , and the sub shaft portion 4 b is rotatably supported by the sub bearing 7 . That is, the crankshaft 4 has a structure in which the eccentric shaft portions 4 c and 4 d rotate eccentrically in the first cylinder chamber 30 and the second cylinder chamber 31 .

The compression mechanism 3 has a first air cylinder 8 on the main shaft portion 4 a side and a second air cylinder 9 on the sub shaft portion 4 b side, and is disposed below the electric motor 2 . The compression mechanism 3 is configured by stacking a main bearing 6 , a first cylinder 8 , a second cylinder 9 , and a sub-bearing 7 sequentially from the upper side toward the lower side.

The first cylinder 8 is a flat plate member in which a substantially cylindrical through hole substantially concentric with the crankshaft 4 (more specifically, the main shaft portion 4 a and the sub shaft portion 4 b ) is formed penetrating in the vertical direction. One end of the through hole (the upper end in FIG. 1 ) is closed by the flange of the main bearing 6 having a substantially T-shaped cross section, and the other end (the lower end in FIG. 1 ) is closed by a The partition plate 5 is closed to form the first cylinder chamber 30 .

A first piston 11 a is provided in the first cylinder chamber 30 of the first cylinder 8 . The first piston 11 a is formed in an annular shape, and is slidably provided on the eccentric shaft portion 4 c of the crankshaft 4 . In addition, in the first cylinder 8 , a vane groove 8 b communicating with the first cylinder chamber 30 and extending in the radial direction of the first cylinder chamber 30 is formed (see FIG. 3 ). Furthermore, the first vane 5a is slidably provided in the vane groove 8b. The front-end|tip part of the 1st vane 5a contacts the outer peripheral part of the 1st piston 11a, As a result, the 1st cylinder chamber 30 is partitioned into the suction chamber 30a and the compression chamber 30b.

In addition, in the first cylinder 8, a suction port 50 for sucking the low-pressure fluid of the refrigerating cycle into the suction chamber 30a of the first cylinder chamber 30 is pierced in the radial direction.

The second cylinder 9 is also a flat plate member through which a substantially cylindrical through hole substantially concentric with the crankshaft 4 (more specifically, the main shaft portion 4 a and the sub shaft portion 4 b ) is formed penetrating in the vertical direction. One end of the through hole (the upper end in FIG. 1 ) is closed by the intermediate partition plate 5 , and the other end (the lower end in FIG. 1 ) is closed by the sub-bearing 7 with a substantially T-shaped cross section. The flange portion is closed to form the second cylinder chamber 31 .

A second piston 11 b is provided in the second cylinder chamber 31 of the second cylinder 9 . The second piston 11b is formed in an annular shape, and is slidably provided on the eccentric shaft portion 4d of the crankshaft 4 . In addition, a vane groove (not shown) extending in the radial direction of the second cylinder chamber 31 communicating with the second cylinder chamber 31 is formed in the second cylinder 9 . Furthermore, a second vane (not shown) is slidably provided in the vane groove (not shown). The tip end portion of the second vane (not shown) contacts the outer peripheral portion of the second piston 11 b, whereby the second cylinder chamber 31 is partitioned into a suction chamber and a compression chamber similarly to the first cylinder chamber 30 .

In addition, in the second cylinder 9, a suction port 51 for sucking the low-pressure fluid of the refrigerating cycle into the suction chamber of the second cylinder chamber 31 is pierced in the radial direction.

To the first cylinder 8 and the second cylinder 9 , an accumulator 40 for allowing gaseous refrigerant to flow into the first cylinder chamber 30 and the second cylinder chamber 31 is connected. Specifically, the accumulator 40 has a container 41 for storing low-pressure refrigerant flowing from an evaporator constituting a refrigeration cycle; an inflow pipe 42 for introducing the low-pressure refrigerant from the evaporator into the container 41 ; and suction pipes 43 and 44 . The suction pipe 43 introduces gaseous refrigerant stored in the container 41 into the first cylinder chamber 30 of the first cylinder 8 , and is connected to the suction port 50 of the first cylinder 8 through a connection pipe 60 . In addition, the suction pipe 44 is used to introduce gaseous refrigerant stored in the container 41 into the second cylinder chamber 31 of the second cylinder 9 , and is connected to the suction port 51 of the second cylinder 9 through the connection pipe 61 .

The connecting pipes 60, 61 have: the suction port side connection parts 60a, 61a on the suction port 50, 51 side; into the suction port 50, 51 side. The suction pipe side connection parts 60b, 61b protrude outside the airtight container 1 and are located in the connection parts 1d, 1e provided on the airtight container 1 . And the ends of the suction pipes 43, 44 are inserted into the suction pipe side connection parts 60b, 61b, the suction pipe side connection parts 60b, 61b, the connection parts 1d, 1e (see FIG. 1 ) of the airtight container 1 and the suction pipes 43, 44 is connected by welding. In addition, of course, the respective lengths of the suction port side connection parts 60a, 61a and the suction pipe side connection parts 60b, 61b can be set arbitrarily.

The connection parts 1d and 1e of the airtight container 1 are installed in the airtight container so as not to interfere with the insertion of the connecting pipes 60 and 61, and are perpendicular to the center line extending in the vertical direction of the airtight container 1 and toward the center of the airtight container 1. 1. In addition, although the height positions of the connection parts 1d and 1e of the airtight container 1 are different, they are formed at overlapping positions when viewed from a plane. In addition, the connection between the connection pipes 60, 61 and the suction ports 50, 51 may be performed by press fitting, or a sealing member may be used.

In addition, the connecting pipes 60 and 61 are used to connect the suction pipes 43 and 44 to the suction ports 50 and 51, so that the suction pipes 43 and 44 can be shortened compared to the shape in which the suction pipes 43 and 44 are directly connected to the suction ports 50 and 51. length. With these structures, the workability at the time of connecting the suction pipes 43, 44 to the suction pipe side connection portions 60b, 61b of the connection pipes 60, 61 is improved. Therefore, the clearance between the suction pipes 43 , 44 and the suction pipe side connection portions 60 b , 61 b of the connection pipes 60 , 61 can be minimized without enlarging conventionally, and occurrence of poor welding or sealing failure can be suppressed.

Fig. 4 is a comparison diagram between the rotary compressor 100 according to Embodiment 1 of the present invention and a conventional one. FIG. 4( a ) is the present embodiment, and FIG. 4( b ) is a conventional example.

The distance between the connection portion 1d and the connection portion 1e of the airtight container 1 is set at a predetermined interval L1 so as not to hinder welding workability or be affected by welding strain. In this point, this embodiment is the same as the conventional example.

Furthermore, in the conventional connecting pipes 600 and 601 , the central axis on the side of the suction ports 50 and 51 and the central axis on the side of the suction pipes 43 and 44 are coaxial as shown by the dotted line in FIG. 4( b ). On the other hand, in the connecting pipes 60 and 61 according to the first embodiment, as shown by the dotted line in FIG. eccentric. More specifically, the central axes of the suction port side connection parts 60a and 61a are eccentric to the direction side closer to each other than the central axes of the suction pipe side connection parts 60b and 61b. In addition, the distance between the suction pipe side connection parts 60b and 61b is the same as the distance between the suction port side connection parts 60a and 61a.

Thereby, the predetermined distance L1 between each connection part 1d, 1e is ensured, and in this example, the axial distance between the 1st cylinder 8 and the 2nd cylinder 9 can be set by reducing L2. By reducing the axial distance between the first cylinder 8 and the second cylinder 9, the distance between the main bearing 6 and the sub-bearing 7, which are the support points of the compressed gas load, becomes shorter, and the crankshaft 4 caused by the compressed gas load can be suppressed. flex.

According to the extent to which deflection of the crankshaft 4 can be suppressed in this way, design changes such as reducing the rigidity of the crankshaft 4 such as reducing the shaft diameter can also be performed, and high efficiency of the compressor by reducing shaft sliding loss can be realized. In addition, here, the distance between the suction pipe side connection parts 60b, 61b is the same as the distance between the suction port side connection parts 60a, 61a, but it does not necessarily have to be the same, as long as the distance between the suction pipe side connection parts 60b, 61b is equal to or It only needs to be larger than the distance between the suction port side connection parts 60a and 61a. In addition, of course, the amount of eccentricity can be set arbitrarily.

Incidentally, the respective flow path cross-sectional areas of the suction port 50 of the first cylinder 8 and the suction port 51 of the second cylinder 9 are when the refrigerant is sucked into the suction chamber 30 a of the first cylinder chamber 30 and the suction port 31 of the second cylinder chamber 31 . When the chamber is used, it is set to an area that does not cause suction pressure loss. The cross-sectional area of the flow path that does not cause suction pressure loss varies depending on the circulating flow rate of the compressor or the characteristics of the refrigerant used. Therefore, in general, among rotary compressors, there are various types of compressors in which the flow passage cross-sectional areas of the suction ports 50 and 51 are different.

Furthermore, from the viewpoint of not increasing the suction pressure loss when sucking the refrigerant into the rotary compressor 100, the suction pipes 43, 44 of the accumulator 40 need to have a flow path cross-sectional area equal to or larger than the flow path cross-sectional area of the suction ports 50, 51. . Therefore, in general, several types of accumulators 40 having different flow path cross-sectional areas of suction pipes 43 and 44 are also prepared corresponding to various types of compressors having different flow path cross-sectional areas of suction ports 50 and 51 . Therefore, when configuring the refrigerating and air-conditioning apparatus, it is necessary to select the accumulator 40 according to the type of the rotary compressor to be used, which has a disadvantage that component management is complicated.

Therefore, if a general-purpose accumulator can be used regardless of the flow path cross-sectional area of the suction ports 50 and 51 , advantages such as elimination of cumbersome parts management can be obtained. Here, consider the case where parts are unified for the accumulator 40 of the suction pipes 43 and 44 having larger pipe diameters than the accumulator 40 shown in FIG. 4 using the conventional connection pipes 600 and 601 shown in FIG. 4( b ). As mentioned above, in the conventional connecting pipes 600 and 601 of FIG. 4( b ), the central axes of the suction port side connecting parts 60 a and 61 a and the central axes of the suction pipe side connecting parts 60 b and 61 b are coaxial. Thus, a predetermined interval L1 between the connection parts 1d and 1e is ensured, and when connecting the suction pipes 43 and 44 with large pipe diameters, the axial direction between the first cylinder 8 and the second cylinder 9 must be enlarged. interval. Therefore, in the conventional structure, it is difficult to unify the accumulators 40 without increasing the distance between them in the axial direction.

On the other hand, in the first embodiment, by using the connecting pipes 60 and 61 in which the central axes of the suction port side connecting parts 60a and 61a and the central axes of the suction pipe side connecting parts 60b and 61b are eccentric, it is possible to ensure the necessary flow. The accumulator with the large pipe diameter of the road area unifies the parts. That is to say, in FIG. 4 , when the accumulator 40 of the suction pipes 43 and 44 having a pipe diameter larger than that of the illustrated accumulator 40 is unified, only the diameters of the suction pipe side connecting parts 60 b and 61 b are used. Larger connecting pipes 60, 61 are sufficient. By using the connecting pipes 60, 61, it is possible to ensure the predetermined interval L1 between the respective connection parts 1d, 1e, and to make the interval between the first air cylinder 8 and the second air cylinder 9 as shown in Fig. 4(a). In a state where the position of the tube is narrowed, the accumulator 40 with a large pipe diameter is used. Thereby, it is possible to enjoy the advantages of quantification of parts manufacturing costs, eliminate cumbersome parts management, etc., and improve productivity.

Hereinafter, the cross-sectional shape of the connecting pipes 60 and 61 will be discussed. In addition, since the cross-sectional shape of the connecting pipes 60 and 61 is determined in accordance with the cross-sectional shape of the suction port 50, first, the cross-sectional shape of the suction port 50 will be described.

Fig. 5 is a diagram showing a cross-sectional shape of the suction port 50 of the rotary compressor 100 according to Embodiment 1 of the present invention.

The cross-sectional shape of the suction port 50 is a non-circular cross-sectional shape in which the dimension D in the rotational direction is larger than the axial dimension H1 of the crankshaft 4 . Therefore, compared with a circular cross-sectional shape having the same flow path cross-sectional area, the axial dimension H1 can be reduced.

In this way, the suction port 50 adopts a non-circular shape so that H1<D, whereby the height H in the axial direction of the first cylinder 8 can be set small. In addition, here, the suction port 50 has been described, but the same applies to the suction port 51 .

6 is an explanatory diagram of the cross-sectional shape of the flow path of the connecting pipe 60 in FIG. 1 , (a) is a transverse sectional view, (b) is a longitudinal sectional view of the suction port side connecting portion 60 a , and (c) is a cross-sectional view of the suction pipe side connecting portion 60 b. Longitudinal view. Here, the connection pipe 60 is shown, but the connection pipe 61 side also has the same structure.

As shown in FIG. 6 , the flow path cross section of the suction port side connecting portion 60 a is formed in a non-circular shape similarly to the suction port 50 , and the flow path cross section of the suction pipe side connecting portion 60 b is circular. In addition, since the suction pipe 43 is generally circular, the cross-sectional shape of the flow path of the suction pipe side connecting portion 60b is also circular. However, in consideration of the suction pressure loss, when the suction port side connecting portion 60a has a non-circular shape, as shown in FIG. 7, the suction pipe side connecting portion 60b is also preferably non-circular. In this way, the cross-sectional shapes of the flow passages of the suction port side connecting portion 60 a and the suction pipe side connecting portion 60 b can be arbitrarily combined with circular and non-circular cross-sectional shapes.

In addition, here, a long hole is used as an example of a non-circular shape as the flow path cross-sectional shape of the suction port side connecting portion 60a. However, the non-circular shape is not limited to the elongated hole in which opposing sides are straight lines parallel to each other as shown in FIGS. In addition, the non-circular shape is a shape in which a plurality of curved portions are arranged on opposite sides to form a straight line, and an elliptical shape is also included.

Fig. 8 is an enlarged sectional view taken along line B-B of Fig. 3 .

As shown in FIG. 8, a gap W needs to be provided between the inner periphery 8a of the first cylinder 8 and the outer periphery 11c of the first piston 11a to avoid mutual contact. The leakage surface of the area S obtained from the product of the clearance W and the axial height H of the first cylinder 8 serves as a leakage flow path communicating the compression chamber 30b and the suction chamber 30a, and is known to cause a decrease in compressor efficiency. Thus, by setting the axial height H of the first cylinder 8 small, the area S of the leakage surface is reduced, and the compressor efficiency can be improved.

In addition, by reducing the axial height H of the first cylinder 8 and the second cylinder 9, the compressed gas load acting on the eccentric shaft portion 4c or 4d of the crankshaft 4 can be reduced. Furthermore, by reducing the height H in the axial direction of the first cylinder 8 and the second cylinder 9, the distance between the main bearing 6 and the sub-bearing 7 serving as a support point for the compressed gas load can also be shortened. Therefore, deflection of the crankshaft 4 due to the compressed gas load can be suppressed, and further efficiency improvement of the compressor can be achieved.

The conditions required for the suction pipe side connection part 60b in the case where the flow path cross-sectional shape of the suction port side connection part 60a is a non-circular shape (a non-circular shape whose axial dimension is smaller than the rotational direction dimension) will be described below. .

9 shows that the suction pipe side connecting portion 60b is circular, the suction port side connecting portion 60a is non-circular, and the flow path cross-sectional area of the suction pipe side connecting portion 60b and the flow path of the suction port side connecting portion 60a Explanatory views of the connecting pipe 60A having the same cross-sectional area, (a) is a transverse sectional view, (b) is a longitudinal sectional view of the suction port side connecting portion 60a, and (c) is a longitudinal sectional view of the suction pipe side connecting portion 60b.

When the same channel cross-sectional area Sa is composed of a non-circular shape and a case of a circular shape, the radial dimension is longer when it is composed of a non-circular shape as shown in FIG. 9 (D1>D0 ). In this way, in the case of connecting the connecting pipe 60A with the same flow path area by making the suction pipe side connection part 60b circular and the suction port side connection part 60a a non-circular shape long in the rotation direction, it is necessary to have a reduced diameter. part, the suction pressure loss caused by the flow resistance of the refrigerant gas cannot be avoided. When the cross-sectional shape of the flow path of the suction pipe side connecting portion 60b is circular, in order to avoid suction pressure loss, the diameter of the suction pipe side connecting portion 60b needs to be equal to or larger than the rotational dimension D1 of the suction port side connecting portion 60a. This corresponds to the condition required for the suction pipe side connecting portion 60b when the flow path cross-sectional shape of the suction port side connecting portion 60a is a non-circular shape (a non-circular shape in which the axial dimension is smaller than the rotational direction dimension).

In this way, in order to reduce the axial height H of the first cylinder 8 and make the cross-sectional shape of the flow path of the suction port side connecting portion 60a a non-circular shape with a short axial dimension, it is necessary to increase the size of the suction pipe 43 . path. Here, in the conventional structure shown in FIG. 4( b ), when the pipe diameters of the suction pipes 43 and 44 are increased as described above, it is necessary to increase the axial distance between the first cylinder 8 and the second cylinder 9 . That is, even if the respective axial heights H of the first cylinder 8 and the second cylinder 9 can be reduced, the axial distance between the first cylinder 8 and the second cylinder 9 must be enlarged, and as a result, the crankshaft 4 cannot be obtained. deflection suppression effect.

On the other hand, when the connecting pipes 60 and 61 of the first embodiment are used, when the pipe diameters of the suction pipes 43 and 44 are increased, it is not necessary to enlarge the axial direction between the first cylinder 8 and the second cylinder 9 . interval. Accordingly, it is possible to reduce the respective axial heights H of the first cylinder 8 and the second cylinder 9 and to reduce the axial distance between the first cylinder 8 and the second cylinder 9 at the same time.

In the following, the influence of the cross-sectional shape of the flow path of the suction port side connecting portion 60a on the compression operation of the rotary compressor 100 will be discussed, and the preferred non-circular shape of the flow path cross-sectional shape of the suction port side connecting portion 60a will be discussed. shape is discussed.

10 is a cross-sectional view of the first cylinder 8 of the rotary compressor 100 according to Embodiment 1 of the present invention, and is an explanatory view of the compression process angle θ determined by the suction port edge 50b and the discharge port edge 70a.

When the size of the suction port 50 in the rotational direction becomes larger, as shown in FIG. The compression process angle θ determined by the opposite side edge portion of the first vane 5a decreases, and the excluded volume decreases.

Here, a comparison is made between the case where an oblong cross-sectional shape of the flow path of the suction port 50 is used and the case where an ellipse is used. When the cross-sectional area of the flow path is the same under the oblong circle and the ellipse, the rotation direction dimension of the suction port 50 on the side of the ellipse is larger than that of the oblong circle. As a result, the compression process angle θ decreases, and the excluded volume decreases. Therefore, when the cross-sectional shape of the flow path of the suction port 50 is non-circular, an oval is more preferable than an ellipse.

As described above, in Embodiment 1, the central axes of the suction port side connection parts 60a and 61a of the connection pipes 60 and 61 are eccentric to the directions closer to each other than the central axes of the suction pipe side connection parts 60b and 61b. Accordingly, the axial distance between the first air cylinder 8 and the second air cylinder 9 can be reduced without hindering the workability of welding with the airtight container 1 . Therefore, the deflection of the crankshaft 4 can be suppressed, the shaft diameter can be reduced without reducing the reliability of the crankshaft 4, and a high-efficiency rotary compressor can be obtained.

Embodiment 2

In the second embodiment, the pressure-tightness of the connecting pipes 60 , 61 to the suction ports 50 , 51 is improved.

The connection pipes 60 , 61 of Embodiment 2 differ from Embodiment 1 in cross-sectional shape on the suction port side connection portions 60 a , 61 a side, and are the same as Embodiment 1 except for that. Hereinafter, the differences between Embodiment 2 and Embodiment 1 will be mainly described. In addition, the structure for improving pressure-tightness is the same in the connection pipes 60 and 61, and below, the connection pipe 60 is demonstrated as a representative.

Fig. 11 is a sectional view of key parts of a rotary compressor according to Embodiment 2 of the present invention, showing when the suction port-side connecting portion 61a of the connecting pipe 60 of Fig. 9(a) is pressed into the suction port 50 whose cross-sectional shape is a long hole. A schematic diagram of the direction of internal stress of the connecting pipe 60 .

The cross-sectional shape of the connection part 60 a on the suction port side of the connection pipe 60 is an elongated hole, and the opposite long side part 60 c of the long hole is a protrusion protruding outward within the range of the press-fit margin of the connection pipe 60 relative to the suction port 50 . Shape 60e. By adopting this structure, it is possible to improve the pressure-tightness of the connection pipe 60 with respect to the suction port 50 . In this regard, as a comparative example, the cross-sectional shape of the suction port-side connecting portion 60 a of the connecting pipe 60 will be described in comparison with the case where the cross-sectional shape of the connecting pipe 60 is a long hole without a convex shape as in the first embodiment.

FIG. 12 shows that as a comparative example, the cross-sectional shape of the suction port-side connecting portion 60a of the connecting pipe 60 is a long hole without a convex shape as in Embodiment 1, and the connecting pipe 60 is pressed into the suction port whose cross-sectional shape is a long hole. A schematic diagram of the direction of the internal stress of the connecting pipe 60 at 50. FIG. 13 is a schematic diagram showing a state in which the connecting pipe 60 is deformed by the internal stress in FIG. 12 .

As shown in FIG. 12 , when the connecting pipe 60 having a cross-sectional shape of a long hole is pressed into the suction port 50 of the long hole, the internal stress generated by the bent portion 60d at both ends of the long hole is transmitted to the bent portion 60d connecting the two ends. A pair of long side portions 60c. In this case, as shown in FIG. 13 , the long side portion 60c is deformed inward as indicated by a blank arrow. When the long side portion 60c is deformed inward, the press-fit sealing performance of the connection pipe 60 with respect to the suction port 50 is reduced. As a result, refrigerant gas in a high-pressure environment in the airtight container 1 flows into the suction chamber 30a from the gap between the deformed portion and the suction port 50, resulting in a decrease in compressor efficiency.

Therefore, in Embodiment 2, the cross-sectional shape of the connection part 60 a on the suction port side of the connection pipe 60 is an elongated hole, and a pair of long side parts 60 c of the long hole facing each other are formed in the shape of the connection pipe 60 relative to the suction port 50 . The convex shape 60e protruding outward within the range of the allowance is pressed. By adopting this structure, by press-fitting the connection pipe 60 into the suction port 50, the internal stress generated by the bent portion 60d is transmitted in a direction in which the convex shape 60e is deformed outward. Thereby, it is possible to obtain the connection pipe 60 in which the decrease in press-fit sealing performance is improved without the long side portion 60c being deformed inward.

As described above, according to the second embodiment, the same effect as that of the first embodiment is obtained, and the long hole facing the long side portion 60 c protrudes outward within the range of the press-fit margin of the connection pipe 60 to the suction port 50 . The convex shape 60e. Accordingly, compared with Embodiment 1, it is possible to obtain the rotary compressor 100 in which the decrease in press-fit sealing performance of the connecting pipe 60 with respect to the suction port is improved.

Claims (9)

1. a rotary compressor has motor and passes through described motor via the driven compressing mechanism of bent axle in seal container, for a plurality of cylinders that are arranged in described compressing mechanism, connects independently respectively the suction pipe of refrigerant gas,

It is characterized in that,

Described a plurality of cylinder has respectively cylinder chamber cylindraceous, and from described cylinder chamber, radially run through and be formed with inhalation port,

This rotary compressor has the connecting pipe that links described inhalation port and described suction pipe,

Described connecting pipe has inhalation port side linking department and suction pipe side linking department,

In 2 described connecting pipes that are connected for the described cylinder adjacent with in described a plurality of cylinders at least 2 each, the central shaft of described inhalation port side linking department is compared to direction close to each other eccentric with the central shaft of described suction pipe side linking department.

2. rotary compressor as claimed in claim 1, it is characterized in that, for 2 described connecting pipes that are connected with described at least 2 adjacent described cylinders, described suction pipe side linking department interval is each other equal to or greater than described inhalation port side linking department interval each other.

3. rotary compressor as claimed in claim 1 or 2, is characterized in that, the flowing path section shape separately of the described inhalation port side linking department of described inhalation port and described connecting pipe is the non-circular shape that axial dimension is less than sense of rotation size.

4. rotary compressor as claimed in claim 3, is characterized in that, the flowing path section shape of the described suction pipe side linking department of described connecting pipe is round-shaped.

5. rotary compressor as claimed in claim 3, is characterized in that, the flowing path section shape of the described suction pipe side linking department of described connecting pipe is the non-circular shape that axial dimension is less than sense of rotation size.

6. rotary compressor as claimed in claim 3, is characterized in that, described non-circular shape is oval or oval.

7. the rotary compressor as described in claim 4 or 5, is characterized in that, described non-circular shape is oval or oval.

8. the rotary compressor as described in any one in claim 1,2,4,5, it is characterized in that, the flowing path section shape of the described inhalation port side linking department of described connecting pipe is slotted hole, described slotted hole has the curved part and a pair of long leg that is connected the curved part at described two ends at two ends, and described a pair of long leg has respectively outstanding laterally convex form.

9. rotary compressor as claimed in claim 3, it is characterized in that, the flowing path section shape of the described inhalation port side linking department of described connecting pipe is slotted hole, described slotted hole has the curved part and a pair of long leg that is connected the curved part at described two ends at two ends, and described a pair of long leg has respectively outstanding laterally convex form.