JP6080646B2 - Rotary compressor - Google Patents

Description

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

  Conventionally, in a refrigerating and air-conditioning apparatus such as an air conditioner or a refrigerator, a rotary compressor having a plurality of cylinders is used. An accumulator for storing refrigerant is connected to the suction side of the rotary compressor so that the refrigerant from the accumulator is sucked into the suction port of each cylinder through the same number of suction pipes as the cylinder. It has become. The accumulator has a configuration in which the container and each suction pipe are fixed, and the end of each suction pipe of the accumulator is connected to each connection portion provided on the surface of the hermetic container of the rotary compressor.

  In this type of rotary compressor, if the suction pipes are close to each other, that is, if the distance between the connection portions provided in the sealed container is close, the welding workability is reduced. Therefore, a structure that does not hinder welding workability is required. Therefore, by shifting the connecting portions provided at different height positions in the sealed container in the circumferential direction of the sealed container, the interval between the connecting portions is increased compared to the case where the same position is set in the circumferential direction. (For example, refer to Patent Document 1). In this rotary compressor, by increasing the interval between the connecting portions, the interval between the suction pipes can be increased, and the welding workability is improved.

  Further, as another technique for improving the workability of welding, there is a rotary compressor in which the suction port of each cylinder and each suction pipe are connected via a connecting pipe (for example, see Patent Document 2). If the connecting pipe is not used, it is necessary to insert each suction pipe into each connection portion of the hermetic container and further connect to each suction port of each cylinder behind it. However, if a connecting pipe is used, the length of the suction pipe itself can be shortened accordingly, so welding is performed compared to the case where each suction pipe is directly inserted into the sealed container and connected to each suction port of each cylinder. Workability can be improved.

Japanese Patent Laid-Open No. 9-079161 (page 3, FIGS. 1 to 3) Japanese Patent Laying-Open No. 2003-214370 (page 4, FIG. 1)

  Since the rotary compressor described in Patent Document 1 shifts the positions of the connecting portions provided in the sealed container in the circumferential direction, the suction pipes are shifted from each other instead of being overlapped in plan view. For this reason, when each suction pipe is connected to each suction port of each cylinder, it is inserted into the connection portion of the sealed container obliquely from different directions with respect to the sealed container. Since each suction pipe is fixed to the accumulator container as described above, there is a problem that it is difficult to simultaneously insert each suction pipe into the connection part of the sealed container from the oblique direction while holding the container.

  Further, the rotary compressor described in Patent Document 1 has a configuration in which the suction pipe is directly connected to the suction port without using the connecting pipe as in Patent Document 2, and this point also causes a decrease in workability. ing.

  In order to improve these workability degradations, a method is conceivable in which the hole diameter and the suction port diameter of each connection portion of the sealed container are increased so that each suction pipe can be easily inserted into each connection portion and each suction port. However, in this case, since the gap between each suction pipe and each connection portion and the gap between each suction pipe and each suction port are increased, there is a concern that a new problem of poor welding or poor sealing may occur.

  By the way, in a rotary compressor having a plurality of cylinders, a main bearing and a sub-bearing that rotatably support the 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 the crankshaft is easily bent as the distance between the main bearing and the sub-bearing increases. In other words, the crankshaft is easily bent as the axial interval between the cylinders becomes longer.

  When the deflection of the crankshaft 4 is increased, the inclination of the crankshaft with respect to the main bearing or the sub-bearing is increased, and the bearing reliability is reduced due to the one-side contact. In order to prevent such bending of the crankshaft, the shaft diameter may be increased to increase the rigidity. However, when the shaft diameter of the crankshaft is increased, the shaft sliding loss is correspondingly increased, leading to a reduction in the efficiency of the compressor. Therefore, a rotary compressor having a plurality of cylinders is required to have a structure that can narrow the axial interval of each cylinder.

  However, narrowing the axial spacing of each cylinder leads to narrowing the spacing of each connection part of the sealed container. Therefore, considering the workability of welding each suction pipe to the suction port of each cylinder, the shaft of each cylinder There was a limit to narrowing the direction interval.

  The present invention has been made in order to solve the above-described problems, and can reduce the axial interval between the cylinders without impairing the welding workability between the sealed container and the suction pipe. Is to obtain a simple rotary compressor.

A rotary compressor according to the present invention has an electric motor in a hermetically sealed container and a compression mechanism that is driven by the electric motor via a crankshaft, and independently sucks refrigerant gas into a plurality of cylinders provided in the compression mechanism. Each of the plurality of cylinders has a cylindrical cylinder chamber, and a suction port is formed through the cylinder chamber in a radial direction. The suction port, the suction pipe, Each of the two connecting pipes connected to at least two adjacent cylinders among the plurality of cylinders. The central axis of the suction port side coupling part is eccentric in the direction closer to each other than the central axis of the suction pipe side coupling part , and the interval between the suction pipe side coupling parts is the same as the interval between the suction port side coupling parts. those are

  According to the present invention, the axial interval between the cylinders can be reduced without impeding the welding workability between the sealed container and the suction pipe, and a highly efficient rotary compressor can be obtained.

It is a longitudinal cross-sectional view of the rotary compressor 100 which concerns on Embodiment 1 of this invention. It is an enlarged view of the compression mechanism 3 of FIG. It is a cross-sectional view of the first cylinder 8 of FIG. It is a comparison figure of the rotary compressor 100 which concerns on Embodiment 1 of this invention, and the conventional form. It is a figure which shows the cross-sectional shape of the suction port 50 of the rotary compressor 100 which concerns on Embodiment 1 of this invention. It is explanatory drawing of the flow-path cross-sectional shape of the connecting pipe 60 of FIG. It is explanatory drawing of the modification of the flow-path cross-sectional shape of the connecting pipe 60 of FIG. It is BB expanded sectional drawing of FIG. A connection pipe in which the suction pipe side connection part 60b is circular, the suction port side connection part 60a is non-circular, and the flow path cross-sectional area of the suction pipe side connection part 60b is the same as the flow path cross-sectional area of the suction port side connection part 60a. It is explanatory drawing of 60A. It 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 diagram of the compression process angle θ determined by the suction port edge 50b and the discharge port edge 70a. It is principal part sectional drawing of the rotary compressor which concerns on Embodiment 2 of this invention. 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 having no convex shape as in the first embodiment, and the connecting pipe 60 is press-fitted into the suction port 50 having a long cross-sectional shape. It is the schematic diagram which showed the direction of the internal stress of the connecting pipe 60 at the time of doing. It is the schematic diagram which showed the state which the connecting pipe 60 deform | transformed by the internal stress of FIG.

Embodiment 1 FIG.
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. FIG. 3 is a cross-sectional view of the first cylinder 8 of FIG. Although the drawing shows a two-cylinder rotary compressor having two cylinders, the rotary compressor of the present invention is not limited to a two-cylinder type, and may be a multi-cylinder type.
The rotary compressor 100 includes an electric motor 2 and a compression mechanism 3 driven by the electric motor 2 via a crankshaft 4 in the sealed container 1.

  The sealed container 1 has a configuration in which the upper dish container 1b and the body 1a are integrated by welding. Refrigerating machine oil (not shown) that lubricates the sliding portion of the compression mechanism 3 is stored at the bottom of the sealed container 1. In addition, a compressor discharge pipe 25 is provided above the sealed container 1 so as to communicate with the internal space of the sealed container 1. Further, connection portions 1d and 1e to which suction pipes 43 and 44 of an accumulator 40 to be described later are independently connected are welded to the body portion 1a of the sealed container 1.

  The electric motor 2 is, for example, variable in rotation speed by inverter control or the like, and includes a stator 2a and a rotor 2b. The electric motor 2 is usually a brushless DC motor that uses a permanent magnet for the rotor 2b. However, an induction motor may be used. The stator 2a is formed in a substantially cylindrical shape, and the outer peripheral portion is fixed to the sealed container 1 by shrink fitting or the like.

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

  As shown in FIG. 2, the crankshaft 4 includes a main shaft portion 4a constituting the upper portion of the crankshaft 4, a subshaft portion 4b constituting the lower portion of the crankshaft 4, and the main shaft portion 4a and the subshaft portion 4b. It is composed of eccentric shaft portions 4c and 4d and an intermediate shaft portion 4e formed therebetween. Here, the center axis of the eccentric shaft portion 4c is eccentric by a predetermined distance from the center axes of the main shaft portion 4a and the sub-shaft portion 4b, and the first shaft 8 in the first cylinder chamber 30 to be described later. Placed in. Further, the eccentric shaft portion 4d has a central axis that is eccentric by a predetermined distance from the central axes of the main shaft portion 4a and the sub-shaft portion 4b, and is placed in a second cylinder chamber 31 of the second cylinder 9 described later. Is to be placed.

  Further, the eccentric shaft portion 4c and the eccentric shaft portion 4d are provided with a phase difference of 180 degrees. The eccentric shaft portion 4c and the eccentric shaft portion 4d are connected by an intermediate shaft portion 4e. 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 is configured such that the eccentric shaft portions 4c and 4d are eccentrically rotated in the first cylinder chamber 30 and the second cylinder chamber 31.

  The compression mechanism 3 includes a first cylinder 8 on the main shaft portion 4 a side and a second cylinder 9 on the sub shaft portion 4 b side, and is disposed below the electric motor 2. The compression mechanism 3 includes a main bearing 6, a first cylinder 8, a second cylinder 9, and a sub bearing 7 that are sequentially stacked from the upper side to the lower side.

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

  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 a ring shape, and is slidably provided on the eccentric shaft portion 4 c of the crankshaft 4. The first cylinder 8 is formed with a vane groove 8 b (see FIG. 3) that communicates with the first cylinder chamber 30 and extends in the radial direction of the first cylinder chamber 30. A first vane 5a is slidably provided in the vane groove 8b. The first cylinder chamber 30 is divided into a suction chamber 30a and a compression chamber 30b by the front end portion of the first vane 5a coming into contact with the outer peripheral portion of the first piston 11a.

  The first cylinder 8 is provided with a suction port 50 in the radial direction for sucking the low-pressure fluid of the refrigeration cycle into the suction chamber 30 a of the first cylinder chamber 30.

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

  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 a ring shape and is slidably provided on the eccentric shaft portion 4d of the crankshaft 4. The second cylinder 9 has a vane groove (not shown) that communicates with the second cylinder chamber 31 and extends in the radial direction of the second cylinder chamber 31. A second vane (not shown) is slidably provided in the vane groove (not shown). When the tip of the second vane (not shown) abuts on the outer peripheral portion of the second piston 11 b, the second cylinder chamber 31 is similar to the first cylinder chamber 30 in the suction chamber and the compression chamber. And divided.

  The second cylinder 9 is provided with a suction port 51 in the radial direction for sucking the low-pressure fluid of the refrigeration cycle into the suction chamber of the second cylinder chamber 31.

  The first cylinder 8 and the second cylinder 9 are connected to an accumulator 40 for allowing a gaseous refrigerant to flow into the first cylinder chamber 30 and the second cylinder chamber 31. Specifically, the accumulator 40 includes a container 41 that stores low-pressure refrigerant that has flowed out of the evaporator constituting the refrigeration cycle, an inflow pipe 42 that guides the low-pressure refrigerant from the evaporator to the container 41, and suction pipes 43 and 44. Yes. The suction pipe 43 guides the gaseous refrigerant out of the refrigerant stored in the container 41 to the first cylinder chamber 30 of the first cylinder 8, and connects the connection pipe 60 to the suction port 50 of the first cylinder 8. Connected through. The suction pipe 44 guides the gaseous refrigerant out of the refrigerant stored in the container 41 to the second cylinder chamber 31 of the second cylinder 9, and is connected to the suction port 51 of the second cylinder 9. 61 is connected.

  The connection pipes 60 and 61 have suction port side connection parts 60a and 61a on the suction ports 50 and 51 side, and suction pipe side connection parts 60b and 61b on the suction pipes 43 and 44 side. The parts 60a and 61a are press-fitted to the suction ports 50 and 51 side. The suction pipe side connecting portions 60b and 61b protrude outside the sealed container 1 and are located in connecting portions 1d and 1e provided in the sealed container 1. Then, end portions of the suction pipes 43 and 44 are inserted into the suction pipe side connection parts 60b and 61b, and the suction pipe side connection parts 60b and 61b, the connection parts 1d and 1e (see FIG. 1) of the sealed container 1 and the suction pipe. The pipes 43 and 44 are connected by welding. As a matter of course, the lengths of the suction port side coupling portions 60a and 61a and the suction pipe side coupling portions 60b and 61b can be arbitrarily set.

  The connection portions 1d and 1e of the hermetic container 1 are sealed so as not to interfere with the insertion of the connecting pipes 60 and 61 so as to be perpendicular to the center line extending in the vertical direction of the hermetic container 1 and to face the center of the hermetic container 1. It is attached to the container 1. Further, the connection portions 1d and 1e of the sealed container 1 are formed at overlapping positions when viewed in plan, although the height positions are different. Note that the connection between the connection pipes 60 and 61 and the suction ports 50 and 51 may be press-fitted or a seal material may be used.

  Further, since the connecting pipes 60 and 61 are used for the connection between the suction pipes 43 and 44 and the suction ports 50 and 51, the suction pipes 43 and 44 are compared with the shape in which the suction pipes 43 and 44 are directly connected to the suction ports 50 and 51. The length of 44 can be shortened. With these configurations, workability when connecting the suction pipes 43 and 44 to the suction pipe side connection portions 60b and 61b of the connection pipes 60 and 61 is improved. For this reason, it is possible to minimize the gap between the suction pipes 43 and 44 and the suction pipe side connection portions 60b and 61b of the connection pipes 60 and 61 as in the prior art, thereby causing poor welding and poor sealing. Can be suppressed.

FIG. 4 is a comparison diagram between rotary compressor 100 according to Embodiment 1 of the present invention and a conventional embodiment. FIG. 4A shows the present embodiment, and FIG. 4B shows a conventional example.
The distance between the connecting portion 1d and the connecting portion 1e of the hermetic container 1 is set to a predetermined interval L1 so as not to hinder welding workability or be affected by welding distortion. This point is the same in this embodiment and the conventional example.

  In the conventional connecting pipes 600 and 601, the central axis on the suction ports 50 and 51 side and the central axis on the suction pipes 43 and 44 side are coaxial, as shown by a one-dot chain line in FIG. On the other hand, the connection pipes 60 and 61 of the first embodiment are configured so that the central axis of the suction port side connection parts 60a and 61a and the suction pipe side connection parts 60b and 61b are shown by the one-dot chain line in FIG. The center axis is eccentric. More specifically, the central axes of the suction port side coupling portions 60a and 61a are eccentric to the direction side closer to each other than the central axes of the suction pipe side coupling portions 60b and 61b. Further, the interval between the suction pipe side connecting portions 60b and 61b is the same as the interval between the suction port side connecting portions 60a and 61a.

  For this reason, the axial interval between the first cylinder 8 and the second cylinder 9 can be set small by L2 in this example while maintaining a predetermined interval L1 between the connecting portions 1d and 1e. It becomes possible. 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 that serve as a support point for the compressed gas load is shortened. The bending of the crankshaft 4 can be suppressed.

  Thus, the design change that reduces the rigidity of the crankshaft 4 such as the reduction of the shaft diameter can be made by the amount that the bending of the crankshaft 4 can be suppressed, and the efficiency of the compressor can be increased by reducing the shaft sliding loss. Here, the interval between the suction pipe side connection portions 60b and 61b is the same as the interval between the suction port side connection portions 60a and 61a, but it is not necessarily the same, and the suction pipe side connection portions 60b, The interval between 61b may be the same as or more than the interval between the suction port side connecting portions 60a and 61a. Of course, the amount of eccentricity can be set arbitrarily.

  By the way, the flow passage cross-sectional areas of the suction port 50 of the first cylinder 8 and the suction port 51 of the second cylinder 9 are such that the refrigerant is in the suction chamber 30 a of the first cylinder chamber 30 and the second cylinder chamber 31. The area is set so as not to cause a suction pressure loss when sucked into the suction chamber. The cross-sectional area of the flow path that does not cause suction pressure loss differs depending on the circulating flow rate of the compressor and the characteristics of the refrigerant used. Therefore, in general, there are a plurality of types of compressors having different flow path cross-sectional areas of the suction ports 50 and 51 in the rotary compressor.

  Further, the suction pipes 43 and 44 of the accumulator 40 have a flow path cut-off equal to or larger than the flow path cross-sectional area of the suction ports 50 and 51 from the viewpoint of not increasing the suction pressure loss when the rotary compressor 100 sucks the refrigerant. Requires area. For this reason, in general, in accordance with a plurality of types of compressors having different flow passage cross-sectional areas of the suction ports 50 and 51, a plurality of types of accumulators 40 having different flow passage cross-sectional areas of the suction pipes 43 and 44, It is prepared. 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 causes inconvenience of complicated parts management.

  For this reason, if a common accumulator can be used regardless of the flow path cross-sectional area of the suction ports 50 and 51, advantages such as elimination of complexity of parts management can be obtained. Here, a case is considered in which parts are unified in the accumulator 40 of the suction pipes 43 and 44 having a pipe diameter larger than that of the accumulator 40 shown in FIG. 4 using the conventional connecting pipes 600 and 601 of FIG. In the conventional connecting pipes 600 and 601 in FIG. 4B, the central axis of the suction port side connecting parts 60a and 61a and the central axis of the suction pipe side connecting parts 60b and 61b are coaxial as described above. For this reason, if it is going to connect the suction pipes 43 and 44 with a large pipe diameter, maintaining the predetermined space | interval L1 between each connection part 1d and 1e, between the 1st cylinder 8 and the 2nd cylinder 9 will be carried out. The axial spacing must be increased. Therefore, in the conventional configuration, it is difficult to unify the accumulator 40 without increasing the axial interval.

  On the other hand, in the first embodiment, it is necessary to use the connection pipes 60 and 61 in which the central axis of the suction port side connection parts 60a and 61a and the central axis of the suction pipe side connection parts 60b and 61b are eccentric. Parts can be unified into an accumulator with a large pipe diameter that can secure the flow path area. That is, in FIG. 4, when the parts are unified in the accumulator 40 of the suction pipes 43 and 44 having a pipe diameter larger than that of the accumulator 40 shown in the figure, the connection pipes 60 and 61b having larger diameters of the suction pipe side connection portions 60b and 61b. 61 may be used. By using the connecting pipes 60 and 61, the predetermined distance L1 between the connecting portions 1d and 1e is maintained, and the distance between the first cylinder 8 and the second cylinder 9 is set as shown in FIG. The accumulator 40 having a large pipe diameter can be used while being narrowed to the position of). As a result, it is possible to improve productivity such as enjoying the quantitative merit of parts production cost and eliminating the complexity of parts management.

  Next, the cross-sectional shape of the connecting pipes 60 and 61 will be examined. In addition, since the cross-sectional shape of the connection pipes 60 and 61 is determined according to 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 rotational dimension D is larger than the axial dimension H1 of the crankshaft 4. Therefore, the axial dimension H1 can be reduced as compared with the circular cross-sectional shape having the same flow path cross-sectional area.

  As described above, the suction port 50 is non-circular and H1 <D, whereby the axial height H of the first cylinder 8 can be set small. Although the suction port 50 has been described here, the same applies to the suction port 51.

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

  As shown in FIG. 6, the flow path cross section of the suction port side connection portion 60 a is configured in a non-circular shape like the suction port 50, and the flow path cross section of the suction pipe side connection 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, considering the suction pressure loss, when the suction port side connecting portion 60a has a non-circular shape, it is desirable that the suction pipe side connecting portion 60b also has a non-circular shape as shown in FIG. As described above, the flow path cross-sectional shapes of the suction port side coupling portion 60a and the suction pipe side coupling portion 60b can be arbitrarily combined with circular and non-circular cross sectional shapes.

  Here, the cross-sectional shape of the flow path of the suction port side connecting portion 60a is a long hole as an example of a non-circular shape. However, as shown in FIGS. 6 and 7, the non-circular shape is not limited to a long hole in which the opposite sides are straight lines parallel to each other, and the shape in which the opposite sides are not perfect straight lines but curves is also possible. Shall be included. In addition, the non-circular shape includes a shape in which the opposite sides are arranged in a straight line by arranging a plurality of curved portions, and also includes an elliptical shape.

8 is an enlarged cross-sectional view taken along line BB in FIG.
As shown in FIG. 8, it is necessary to provide a clearance W between the inner periphery 8a of the first cylinder 8 and the outer periphery 11c of the first piston 11a in order to avoid mutual contact. The leakage surface having an area S obtained by the product of the clearance W and the axial height H of the first cylinder 8 becomes a leakage flow path that connects the compression chamber 30b and the suction chamber 30a, and causes a reduction in compressor efficiency. It is known to be. For this reason, by setting the axial height H of the first cylinder 8 small, it is possible to reduce the area S of the leakage surface and improve the compressor efficiency.

  Further, 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 the eccentric shaft portion 4d of the crankshaft 4 can be reduced. Furthermore, the axial height H of the first cylinder 8 and the second cylinder 9 can be reduced, so that the distance between the main bearing 6 and the sub-bearing 7 serving as a support point for the compressed gas load can be shortened. Connected. Therefore, the bending of the crankshaft 4 due to the compressed gas load can be suppressed, and the compressor can be further improved in efficiency.

  Next, requirements required for the suction pipe side coupling portion 60b when the flow path cross-sectional shape of the suction port side coupling portion 60a is a non-circular shape (a non-circular shape whose axial direction dimension is smaller than the rotational direction dimension) will be described.

  FIG. 9 shows that the suction pipe side coupling portion 60b is circular, the suction port side coupling portion 60a is non-circular, and the flow path sectional area of the suction pipe side coupling portion 60b and the flow path sectional area of the suction port side coupling portion 60a are It is explanatory drawing of 60 A of connecting pipes made the same, (a) is a cross-sectional view, (b) is a longitudinal cross-sectional view of the suction port side connection part 60a, (c) is a longitudinal cross-sectional view of the suction pipe side connection part 60b. .

  In the case where the same channel cross-sectional area Sa is configured in a non-circular shape and in the case where it is configured in a circular shape, the radial dimension is longer when configured in a non-circular shape as shown in FIG. 9 (D1> D0). As described above, in the case of the connecting pipe 60A in which the suction pipe side connecting part 60b is circular and the suction port side connecting part 60a is connected in the same flow area with a non-circular shape that is long in the rotation direction, the reduced diameter part must be provided. Therefore, the suction pressure loss due to the flow path resistance of the refrigerant gas is inevitable. In order to avoid the suction pressure loss while the cross-sectional shape of the flow path of the suction pipe side connection part 60b is circular, the diameter of the suction pipe side connection part 60b is equal to or larger than the rotational direction dimension D1 of the suction port side connection part 60a. There is a need to. This corresponds to the requirement required for the suction pipe side coupling portion 60b when the flow path cross-sectional shape of the suction port side coupling portion 60a is a non-circular shape (a non-circular shape whose axial direction dimension is smaller than the rotational direction dimension).

  In this way, when the cross-sectional shape of the flow path of the suction port side coupling portion 60a is a non-circular shape with a short axial dimension in order to reduce the axial height H of the first cylinder 8, the pipe diameter of the suction pipe 43 is reduced. Need to be increased. Here, in the conventional structure shown in FIG. 4B, when the pipe diameters of the suction pipes 43 and 44 are increased as described above, the axial distance between the first cylinder 8 and the second cylinder 9 is increased. Need to spread. That is, even if the axial height H of each 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 increased. After all, the effect of suppressing the deflection of the crankshaft 4 cannot be obtained.

  On the other hand, when the connection pipes 60 and 61 according to the first embodiment are used, the axial distance between the first cylinder 8 and the second cylinder 9 is increased when the pipe diameters of the suction pipes 43 and 44 are increased. There is no need to spread For this reason, reducing the axial height H of each of the first cylinder 8 and the second cylinder 9 and reducing the axial distance between the first cylinder 8 and the second cylinder 9. Can be achieved.

  Next, 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 is examined, and a preferable shape as the non-circular shape of the cross section of the flow path of the suction port side connecting portion 60a is examined. To do.

  FIG. 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 diagram of the compression process angle θ determined by the suction port edge 50b and the discharge port edge 70a.

  As the rotational direction dimension of the suction port 50 increases, as shown in FIG. 10, the suction port edge 50b (Y point, the opposite edge of the first vane 5a) and the discharge port edge 70a of the discharge port 70 (Z point, first point) The compression process angle θ determined by the opposite side edge of the vane 5a of the first vane 5a decreases, and the excluded volume decreases.

  Here, the case where the cross-sectional shape of the flow path of the suction port 50 is an ellipse is compared with the case where it is an ellipse. If the cross-sectional areas of the ellipse and the ellipse are the same, the ellipse has a larger rotational direction dimension of the suction port 50 than the ellipse. For this reason, the compression process angle θ decreases and the excluded volume decreases. Therefore, when the cross-sectional shape of the suction port 50 is a non-circular shape, an ellipse is preferable to an ellipse.

  As described above, in the first embodiment, the central axes of the suction port side connection portions 60a and 61a of the connection pipes 60 and 61 are eccentric in the direction closer to each other than the central axes of the suction pipe side connection portions 60b and 61b. doing. For this reason, the axial direction space | interval between the 1st cylinder 8 and the 2nd cylinder 9 can be made small, without inhibiting the welding workability | operativity with the airtight container 1. FIG. Therefore, the bending of the crankshaft 4 can be suppressed, the shaft diameter can be reduced without reducing the reliability of the crankshaft 4, and a highly efficient rotary compressor can be obtained.

Embodiment 2. FIG.
In the second embodiment, the pressure sealability of the connection pipes 60 and 61 with respect to the suction ports 50 and 51 is improved.

  The second embodiment is different from the first embodiment in the cross-sectional shape of the connection pipes 60, 61 on the suction port side connecting portions 60a, 61a side, and the other parts are the same as those in the first embodiment. In the following, the second embodiment will be described focusing on the differences from the first embodiment. In addition, since the structure for improving the pressure sealing property is the same in the connecting pipes 60 and 61, the connecting pipe 60 will be described below as a representative.

FIG. 11 is a cross-sectional view of a main part of the rotary compressor according to the second embodiment of the present invention. The suction port side connection portion 61a of the connection pipe 60 in FIG. It is the schematic diagram which showed the direction of the internal stress of the connection pipe 60 at the time of press-fitting in.
The suction port side connection part 60a of the connection pipe 60 has a cross-sectional shape as a long hole, and the long side part 60c opposite to the long hole projects outwardly within the range of the press-fitting allowance for the suction port 50 of the connection pipe 60. It was set as the convex shape 60e. With this structure, it is possible to improve the pressure sealing performance of the connecting 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 60a of the connecting pipe 60 will be described in comparison with a case where the elongated hole has no convex shape as in the first embodiment.

  FIG. 12 shows, as a comparative example, the cross-sectional shape of the suction port side connection portion 60a of the connection pipe 60 is a long hole without a convex shape as in the first embodiment, and the connection pipe 60 is a suction hole having a cross-sectional shape of a long hole. FIG. 5 is a schematic diagram showing the direction of internal stress of a connecting pipe 60 when press-fitted into a port 50. FIG. 13 is a schematic view showing a state where the connecting pipe 60 is deformed by the internal stress of FIG.

  As shown in FIG. 12, when a connecting tube 60 having a long hole in cross-sectional shape is press-fitted into the long hole suction port 50, the internal stress generated in the curved portions 60d at both ends of the long hole is caused by the curved portions 60d at both ends. Is transmitted to the pair of long side portions 60c. If it does so, there exists a possibility that the long side part 60c may deform | transform inside as shown by the white arrow as shown in FIG. When the long side part 60c deform | transforms inside, the press-fit sealing property with respect to the suction port 50 of the connection pipe 60 will fall. For this reason, the refrigerant gas in the high-pressure atmosphere in the hermetic container 1 flows into the suction chamber 30a from the gap between the deformed portion and the suction port 50, and there is a possibility that the compressor efficiency is lowered.

  Therefore, in the second embodiment, the cross-sectional shape of the suction port side connection portion 60a of the connection pipe 60 is a long hole, and a pair of long side portions 60c of the long hole facing each other are connected to the suction port 50 of the connection pipe 60. It was set as the convex shape 60e protruded outward in the range of the press-fitting allowance with respect to. With this structure, the internal stress generated in the curved portion 60d due to the press-fitting of the connecting pipe 60 into the suction port 50 is transmitted in the direction of deforming the convex shape 60e outward. For this reason, it becomes possible to obtain the connecting pipe 60 in which the press-fit sealing property is reduced without the long side portion 60c being deformed inward.

  As described above, according to the second embodiment, the same effects as those of the first embodiment can be obtained, and the long side portions 60c of the elongated holes can be connected to the suction port 50 of the connecting pipe 60 with respect to the press-fitting margin. In this range, a convex shape 60e protruding outward is formed. Thereby, it is possible to obtain the rotary compressor 100 in which the deterioration of the press-fit sealing property with respect to the suction port of the connecting pipe 60 is improved as compared with the first embodiment.

  DESCRIPTION OF SYMBOLS 1 Airtight container, 1a trunk | drum, 1b Top 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 Subshaft part, 4c Eccentric shaft part, 4d Eccentric shaft part, 4e Intermediate shaft part, 5 Intermediate partition plate, 5a First vane, 6 Main bearing, 7 Sub bearing, 8 First cylinder, 8a Inner circumference, 8b Vane groove, 9 2nd cylinder, 11a 1st piston, 11b 2nd piston, 11c outer periphery, 25 compressor discharge pipe, 26 glass terminal, 27 lead wire, 30 1st cylinder chamber, 30a suction chamber, 30b compression chamber, 31 Second cylinder chamber, 40 accumulator, 41 container, 42 inflow pipe, 43 suction pipe, 44 suction pipe, 50 suction port, 50b suction port edge, 51 suction port, 60 connecting pipe, 60A Connection pipe, 60a Suction port side connection part, 60b Suction pipe side connection part, 60c Long side part, 60d Curved part, 60e Convex shape, 61 Connection pipe, 61a Suction port side connection part, 61b Suction pipe side connection part, 70 Discharge Port, 70a Discharge port edge, 100 rotary compressor.

Claims (6)

A rotary type having an electric motor in a hermetic container and a compression mechanism driven by the electric motor via a crankshaft, and refrigerant gas suction pipes are independently connected to a plurality of cylinders provided in the compression mechanism A compressor,
Each of the plurality of cylinders has a cylindrical cylinder chamber, and a suction port is formed through the cylinder chamber in a radial direction.
A connecting pipe connecting the suction port and the suction pipe;
The connection pipe has a suction port side connection part and a suction pipe side connection part,
Among the plurality of cylinders, each of the two connecting pipes connected to at least two adjacent cylinders has a central axis of the suction port side connecting portion closer to each other than a central axis of the suction pipe side connecting portion. A rotary compressor characterized by being eccentric in the direction and having an interval between the suction pipe side connecting portions equal to an interval between the suction port side connecting portions . 2. The rotation according to claim 1, wherein a flow path cross-sectional shape of each of the suction port and the suction port side connection portion of the connection pipe is a non-circular shape having an axial dimension smaller than a rotational dimension. Compressor. The rotary compressor according to claim 2, wherein a flow path cross-sectional shape of the suction pipe side connection portion of the connection pipe is a circular shape. The rotary compressor according to claim 2, wherein a flow path cross-sectional shape of the suction pipe side connection portion of the connection pipe is a non-circular shape whose axial dimension is smaller than the rotational dimension. The rotary compressor according to any one of claims 2 to 4, wherein the non-circular shape is an ellipse or an ellipse. The inlet port side connecting portion of the connecting pipe has an elongated channel cross-sectional shape, and the elongated hole has a curved portion at both ends and a pair of long sides connecting the curved portions at both ends, each long side portion, rotary compressor according to any one of claims 1 to 4, characterized in that it has a convex shape projecting outwardly.

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