JP6437204B2 - Rotary compressor - Google Patents

Description

  The present invention relates to a rotary compressor.

  Conventionally, as a compressor constituting a refrigeration cycle in an air conditioner, a refrigerator, or the like, a rotary compressor including a cylinder and a rotor that rotates eccentrically from the axis of the cylinder inside the cylinder is known. The rotary compressor sucks low-pressure refrigerant circulating in the refrigerant circuit through a suction pipe connected to the side wall of the cylinder into the cylinder chamber, and discharges the high-pressure refrigerant compressed in the cylinder chamber from the discharge pipe as the rotor rotates. To the outside.

  In such a rotary compressor, a structure in which members such as a cylinder main body, an upper bearing, a lower bearing, and a muffler forming a muffler chamber constituting a rotary compression mechanism are fastened by bolts. In the two-cylinder rotary compression mechanism, the separator plate that partitions the cylinders is similarly fastened to the cylinder body and the like by bolts.

  In the rotary compressor disclosed in Patent Document 1 below, bolt tightening is performed at a position closer to the inner peripheral side (cylinder chamber side) than the bolt fastening portion of the cylinder, that is, between the cylinder inner wall and the bolt hole. Grooves are provided to alleviate distortion caused by the above.

Japanese Unexamined Patent Publication No. 63-186888

As described above, the conventional rotary compressor employs a structure in which the cylinder body, bearings, and muffler constituting the rotary compression mechanism are overlapped and integrated by bolt tightening. There is a concern that the inner diameter of the cylinder may be deformed by tightening the bolt.
That is, as shown in FIG. 7, when a bolt is screwed into a bolt hole 9a of a cylinder body 9 provided with an inner screw and fastened, the inner wall surface 9b of the cylinder chamber 8 in the cylinder body 9 is in the vicinity of the bolt fastening portion. It may be deformed so as to bulge inward (in the direction of the center of the cylinder chamber). When such deformation occurs, the gap (inter-surface distance) between the outer peripheral surface of the rotating rotor 12 and the inner wall surface 9b of the cylinder body 9 forming the cylinder chamber 8 is the smallest in the peripheral region of the bolt hole 9a. In FIG. 7, the deformation due to bolt tightening is greatly exaggerated for the sake of clarity.

Accordingly, the rotational axis center position of the rotor 12 is adjusted so as to ensure a predetermined clearance set value g in the bolt hole peripheral region with the smallest clearance so that the rotor 12 does not contact the inner wall surface 9b of the cylinder body 9. Is done. That is, the rotational axis center position of the rotor 12 is changed from C to C ′ when there is no deformation.
However, such adjustment of the gap setting value g increases the gap dimension in other regions spaced from the bolt holes 9a in the circumferential direction. For this reason, at the time of compression, the leakage amount of the compressed fluid flowing out from the high pressure side to the low pressure side increases, and as a result, the compression efficiency of the rotary compressor decreases. Therefore, in a rotary compressor that employs bolt fastening to integrate the rotary compression mechanism, the cylinder inner diameter change (deformation) due to bolt tightening is suppressed, and the amount of compressed fluid leakage during compression is reduced, resulting in higher efficiency. It is desirable to achieve.
The present invention has been made to solve the above-described problems, and the object of the present invention is to suppress a change in the inner diameter of the cylinder due to bolt tightening and to reduce the amount of compressed fluid leakage during compression, thereby improving efficiency. It is to provide a rotary compressor that can be achieved.

In order to solve the above problems, the present invention employs the following means.
In the rotary compressor according to the present invention, a rotary compression mechanism driven via a crankshaft connected to a drive source is installed on each of a cylinder body forming a cylinder chamber and upper and lower surfaces of the cylinder body. A bearing that supports the shaft, and a rotor that is fitted in an eccentric portion of the crankshaft and rotates in the cylinder chamber, and at least a bolt that penetrates the cylinder body and the bearing in the axial direction of the crankshaft. A rotary compressor integrated by fastening, wherein a deformation absorbing portion that guides deformation at the time of bolt fastening to at least one of a radially outward direction and a circumferential direction is provided in a region around the bolt hole of the cylinder body. It is a feature.

According to such a rotary compressor, a deformation absorbing portion that guides deformation at the time of bolt tightening to at least one of the radially outward direction and the circumferential direction is provided in the region around the bolt hole of the cylinder body. The deformation of the cylinder body is directed from the bolt fastening portion toward the outer circumferential direction or the circumferential direction of the cylinder body. Therefore, it is possible to prevent or suppress the inner wall surface of the cylinder chamber from bulging toward the axial center and reducing the cylinder inner diameter when the bolt is fastened.
In other words, the above-described deformation absorbing portion thins the radial direction of the cylinder body on the outer peripheral side from the bolt fastening portion, for example, so that the deformation of the cylinder body caused by bolt tightening is guided in other directions except the inside of the cylinder chamber. Thus, it is a region where the rigidity is lowered.

  In the above rotary compressor, the deformation absorbing portion is preferably a groove provided in a region excluding the inner side in the radial direction from the bolt hole and penetrating in the axial direction of the crankshaft. The deformation of the main body is directed outward in the radial direction and in the circumferential direction from the bolt fastening portion over the entire region in the thickness direction (axial direction). For this reason, the deformation in which the inner diameter of the cylinder chamber bulges toward the axial center side can be prevented or suppressed throughout the thickness direction of the cylinder body. Moreover, since such a penetration groove functions also as a hollow heat insulation layer, it can suppress that the heat from outer periphery is transmitted to compression space.

  In the above rotary compressor, the deformation absorbing portion may be cut out by penetrating the outer peripheral surface of the cylinder body in the axial direction of the crankshaft. By providing such a notch, the radial dimension of the cylinder body is reduced over the entire area in the thickness direction on the outer peripheral side of the bolt fastening portion. Therefore, the deformation of the cylinder body due to the bolt fastening is directed radially outward from the bolt fastening portion having low rigidity. Can be prevented or suppressed.

  According to the rotary compressor of the present invention described above, the deformation of the cylinder body caused by the bolt fastening can be guided in a direction other than the inside in the radial direction, so that the deformation such that the inner wall of the cylinder chamber bulges out to the cylinder chamber inner side. Can be prevented or suppressed. For this reason, the gap between the outer peripheral surface of the rotor and the inner wall surface of the cylinder main body forming the cylinder chamber can be made uniform over the entire circumference to a predetermined gap set value g (see FIG. 7). It is possible to reduce the amount of compressed fluid that flows out from the high pressure side to the low pressure side during compression, thereby achieving high efficiency.

It is a figure which shows 1st Embodiment of the rotary compressor which concerns on this invention, (a) is a top view of the cylinder main body which provided the through-slot as a deformation | transformation absorption part, (b) is A- of FIG. 1 (a). It is A sectional drawing. It is a top view of the cylinder main body which shows the deformation | transformation of the through groove shown to Fig.1 (a). It is a top view of the cylinder main body which shows the 1st modification of the through groove | channel shown to Fig.1 (a). It is a top view of the cylinder main body which shows the 2nd modification of the through groove | channel shown to Fig.1 (a). It is a figure which shows 2nd Embodiment of the rotary compressor which concerns on this invention, and is a top view of the cylinder main body which provided the thin part as a deformation | transformation absorption part. It is a longitudinal cross-sectional view which shows the structural example of the sealed single cylinder as an example of the rotary compressor which concerns on this invention. It is a top view which shows the conventional structure of a cylinder main body.

Hereinafter, an embodiment of a rotary compressor according to the present invention will be described with reference to the drawings.
FIG. 6 is a longitudinal sectional view showing a configuration example of a sealed single cylinder as an example of a rotary compressor. In the following, an embodiment applied to a single-cylinder rotary compressor will be described for the sake of convenience, but the present invention can be similarly applied not only to a two-cylinder rotary compressor but also to a rotary compression mechanism of a compressor having a plurality of different compression mechanisms. Needless to say.

The hermetic rotary compressor 1 includes a housing 2 having a hermetic structure. The housing 2 includes a cylindrical center housing 2A, an upper housing 2B that seals the upper part of the center housing 2A, and a lower housing 2C that seals the lower part of the center housing 2A. An electric motor 4 composed of a stator 5 and a rotor 6 is fixedly installed as a drive source on the upper side in the center housing 2A.
A crankshaft (rotary shaft) 7 is integrally coupled to the rotor 6.

  As is well known, this electric motor 4 has an axial offset amount between the stator 5 and the rotor 6, and uses an axial magnet pull force acting between the stator 5 and the rotor 6 to stabilize operation. It sometimes has a function of lifting the rotor 6 and the crankshaft 7 upward. With this function, a thrust reduction mechanism that reduces a thrust force acting between a thrust end surface formed at an eccentric portion of the crankshaft 7 and end surfaces of an upper bearing 10 and a lower bearing 11 described later is configured.

  A single-cylinder rotary compression mechanism 3 is installed below the electric motor 4. The rotary compression mechanism 3 includes a cylinder body 9 in which a cylinder chamber 8 is formed, an upper bearing 10 and a lower bearing 11 that are fixedly installed on the upper and lower portions of the cylinder body 9 and seal the upper and lower portions of the cylinder chamber 8. A rotor 12 that is fitted to the eccentric portion 7A of the crankshaft 7 and rotates on the inner peripheral surface of the cylinder chamber 8, a blade and a blade pressing spring (not shown) that divides the inside of the cylinder chamber 8 into a suction side and a discharge side It is set as the structure provided with.

  This rotary compression mechanism 3 is fixedly installed by either plug welding or caulking and fixing either of the cylinder body 9 or the upper bearing 10 to the inner peripheral surface of the center housing 2A at a plurality of positions on the circumference. Can be integrally assembled to the fixedly installed member.

The rotary compression mechanism 3 sucks the low-pressure refrigerant gas of the compressed fluid into the cylinder chamber 8 from the accumulator 14 provided integrally with the rotary compressor 1 via the suction pipe 13, and rotates the rotor 12 with this refrigerant gas. After being compressed, the air is discharged into the upper muffler chamber 15 and the lower muffler chamber 16 which are formed using the upper bearing 10 and the lower bearing 11. The compressed high-pressure refrigerant gas is combined in the upper muffler chamber 15 and then discharged into the center housing 2A. In addition, the inside of the upper muffler chamber 15 and the lower muffler chamber 16 and the inside of the center housing 2 </ b> A are in a state where there is substantially no pressure difference.
The high-pressure refrigerant gas flows through a gas passage hole (not shown) provided around the electric motor 4 and is guided to the upper space of the electric motor 4. It is sent out to the outside, that is, the refrigeration cycle side.

The rotary compression mechanism 3 described above includes a cylinder body 9, an upper bearing 10 and a lower bearing 11 disposed above and below the cylinder body 9, and a lower muffler 16 </ b> A that forms a lower muffler chamber 16 below the lower bearing 11. Are integrated by screwing and fastening bolts 18 penetrating in the axial direction of the crankshaft 7.
Both the upper muffler chamber 15 and the lower muffler chamber 16 are portions where there is no pressure difference between inside and outside. However, in the illustrated configuration example, since the sealing performance against the lubricating oil is required, only the lower muffler 16A is fastened by the bolt 18, but both the upper muffler 15A and the lower muffler 16A are fastened by the bolt 18. There is no particular limitation on the structure, or a structure in which only one of the bolts 18 is fastened.

<First Embodiment>
As described above, the rotary compression mechanism 3 driven via the crankshaft 7 connected to the electric motor 4 serving as the drive source is installed on the cylinder body 9 forming the cylinder chamber 8 and the upper and lower surfaces of the cylinder body 9 respectively. An upper bearing 10 and a lower bearing 11 that support the crankshaft 7 and a rotor 12 that is fitted in the eccentric portion 7A of the crankshaft 7 and rotates in the cylinder chamber 8, and includes at least a cylinder body 9 and an upper portion. In the rotary compressor 1 having a structure in which the bearing 10 and the lower bearing 11 are integrated by fastening bolts 18 penetrating in the axial direction of the crankshaft 7, for example, as shown in FIG. Is provided with a through-groove 20 of a deformation absorbing portion provided in a peripheral region of the bolt hole 9a.
When the bolt 18 is fastened, the through-groove 20 is deformed by the bolt 18 screwed into the bolt hole 9a of the cylinder body 9 so that at least one of the cylinder body 9 in the radially outward direction and the circumferential direction is deformed. A low-rigidity region is formed so as to be guided to

The through groove 20 of the embodiment shown in FIG. 1 is an arc-shaped groove formed in the vicinity of the outer peripheral side of the bolt hole 9a, and is directed through the thickness t of the cylinder body 9 in the axial direction of the crankshaft 7. ing. In the periphery of the bolt hole 9a, the dimension L2 on the outer peripheral side in the radial direction is set to be smaller than the dimension L1 on the inner peripheral side (L2 <L1).
As a result, in the periphery of the bolt hole 9a, the rigidity on the outer peripheral side in the radial direction with the dimension L2 smaller than the dimension L1 is lower than that on the inner peripheral side. A rigid region is formed.

  The rotary compressor 1 provided with such a through-groove 20 receives an input in a direction of expanding the bolt hole 9a generated when the bolt 18 is screwed and fastened, so that the periphery of the bolt hole 9a of the cylinder main body 9 is received. Is deformed. For example, as shown in FIG. 2, this deformation bulges into the through groove 20 toward the radially outer peripheral side having low rigidity around the bolt hole 9 a. In this case as well, the deformation due to bolt tightening is greatly exaggerated for the sake of convenience of clearly illustrating the deformation.

That is, when the bolt 18 is fastened, the cylinder body 9 inner wall surface 20a of the through groove 20 expands in the direction of the groove space 20b by releasing the deformation of the cylinder body 9 toward the radially outer peripheral side of the bolt hole 9a and absorbing the input. Since the bulging portion 21 is formed by being deformed so as to come out, deformation in the direction of reducing the cylinder inner diameter can be prevented or suppressed. In other words, in the present embodiment, a through groove 20 is provided between the bolt hole 9a and the outer wall surface 9c of the cylinder body 9 so as to escape deformation caused by bolt tightening, and the outer peripheral side of the bolt hole 9a is preferentially provided. Since it is made to deform | transform, it can suppress that a cylinder inner diameter of the cylinder chamber 8 deform | transforms.
As a result, in the rotary compression mechanism 3, the rotational axis center position of the rotor 12 is set to C, and a predetermined clearance set value g can be secured over the entire circumference, so that the compressed fluid leaking from the high pressure side to the low pressure side can be secured. The amount of leakage can be reduced.

Further, since the through groove 20 is provided so as to penetrate in the axial direction of the crankshaft 7, the deformation of the cylinder body 9 due to the bolt fastening is directed outward in the radial direction from the bolt hole 9a over the entire region of the thickness t. . For this reason, deformation at the time of bolt fastening that reduces the inner diameter of the cylinder chamber 8 can be prevented or suppressed throughout the thickness direction of the cylinder body 9.
Furthermore, the provision of such a through groove 20 also forms a hollow heat insulating layer on the outer peripheral side of the cylinder chamber 8, so that heat input from the outer periphery on the high temperature side enters the low temperature cylinder chamber 8. Suppresses transmission and contributes to improvement of compression efficiency.

By the way, the groove serving as the deformation absorbing portion described above is not limited to the arc-shaped through groove 20 shown in FIGS. 1 and 2, and various modifications as described below, for example, are possible.
In the first modification shown in FIG. 3, a substantially semicircular through groove 20A is formed on the outer peripheral side in the radial direction from the bolt hole 9a. The through groove 20A forms a low rigidity region so as to surround a substantially semicircular region on the outer peripheral side from the bolt hole 9a, and not only absorbs deformation at the time of bolt fastening to the outer peripheral side in the radial direction but also in the circumferential direction. Further, since the deformation is absorbed, the deformation of the cylinder inner diameter of the cylinder chamber 8 can be suppressed as in the above-described embodiment.

  Further, in the second modification shown in FIG. 4, arc-shaped through grooves 20L and 20R are formed on both sides in the circumferential direction of the bolt hole 9a. The through-grooves 20L and 20R form a low rigidity region on both sides in the circumferential direction of the bolt hole 9a so as to absorb deformation at the time of bolt fastening mainly in the circumferential direction. And similarly to a 1st modification, it can suppress that a cylinder inner diameter of the cylinder chamber 8 deform | transforms.

<Second Embodiment>
In the embodiment described below, for example, as shown in FIG. 5, a notch forming portion 30 formed by providing a recessed groove portion 9 d that is notched through the outer peripheral surface of the cylinder body 9 in the axial direction of the crankshaft 7. Let it be a deformation absorber. In addition, the same code | symbol is attached | subjected to the part similar to embodiment mentioned above and its modification, and the detailed description is abbreviate | omitted.
The illustrated recessed groove portion 9d is a groove in the thickness direction having a substantially semicircular cross section provided on the outer wall surface 9c of the cylinder body 9, and on the radial extension line passing through the centers of the cylinder chamber 8 and the bolt hole 9a. , Provided over the entire thickness t. Note that the cross-sectional shape of the groove portion 9 d, for example, be a rectangular cross-sectional shape or a triangular cross-sectional shape and is not particularly limited.

By providing such a groove portion 9 d, the radial dimension of the cylinder body 9 is smaller than the inner circumferential side over the entire outer peripheral side thickness direction of the bolt holes 9a in the notch forming section 30. That is, the notch forming portion 30 on the outer peripheral side of the bolt hole 9a is a low rigidity region having a smaller radial dimension than the inner peripheral side of the bolt hole 9a. More outward in the radial direction. As a result, the deformation in which the inner diameter of the cylinder chamber 8 bulges toward the axial center is prevented or suppressed in the entire thickness direction of the cylinder body 9.
The formation of the low-rigidity area by such groove part 9 d is also possible to combine through groove 20 and as appropriate with the variation of the embodiment described above.

  As described above, according to the above-described embodiment, the deformation main body 9 is deformed by the bolt tightening, and the deformation absorbing portion is configured to be guided in the other direction except the inside of the cylinder chamber 8. The deformation of the cylinder main body 9 is directed from the bolt hole 9a of the bolt fastening portion toward the outer peripheral direction (radially outward) or the circumferential direction of the cylinder main body 9. Such a deformation absorbing portion is made rigid by reducing the size in the radial direction and the circumferential direction of the cylinder main body 9 on the outer peripheral side from the bolt hole 9a serving as a bolt fastening portion (the size in which the material of the cylinder main body 9 exists). Therefore, when the bolt is fastened when assembling the rotary compression mechanism 3, the inner wall surface 9b of the cylinder chamber 8 is expanded toward the axial center side by inducing deformation toward the low rigidity side. Deformation that reduces the inner diameter can be prevented or suppressed.

  For this reason, since the space between the outer peripheral surface of the rotor 12 and the inner wall surface 9b of the cylinder body 9 forming the cylinder chamber 8 can be uniformized to a predetermined gap set value g over the entire periphery, the rotary compressor 1 High efficiency can be achieved by reducing the amount of compressed fluid leaking from the high pressure side to the low pressure side during compression. Such high efficiency of the rotary compressor 1 becomes more conspicuous particularly when a compressed fluid (for example, R32 refrigerant) used at a high pressure is used as a target.

Moreover, this embodiment which provides a deformation | transformation absorption part in an outer peripheral side ensures miniaturization of the rotary compressor 1 and favorable sealing performance compared with the patent document 1 which provided the groove | channel in the inner peripheral side from the bolt hole 9a. It also has the advantage of being easy to do.
The present invention is not limited to the above-described embodiment, and can be applied to a rotary compression mechanism of a compressor in which a rotary compression mechanism and a scroll compression mechanism are combined. Can be changed as appropriate.

DESCRIPTION OF SYMBOLS 1 Rotary compressor 2 Housing 2A Center housing 3 Rotary compression mechanism 4 Electric motor 7 Crankshaft 7A Eccentric part 8 Cylinder chamber 9 Cylinder main body 9a Bolt hole 9b Inner wall surface 9c Outer wall surface 9d Groove part 10 Upper bearing 11 Lower bearing 12 Rotor 15 Upper part Muffler chamber 15A Upper muffler 16 Lower muffler chamber 16A Lower muffler 20, 20A, 20L, 20R Through groove (deformation absorbing part)
21 bulge part 30 notch formation part (deformation absorption part)

Claims (2)

A rotary compression mechanism driven via a crankshaft connected to a drive source; a cylinder body that forms a cylinder chamber; a bearing that is installed on each of the upper and lower surfaces of the cylinder body and supports the crankshaft; and the crank A rotary compressor having a rotor fitted in an eccentric part of a shaft and rotating in the cylinder chamber, wherein at least the cylinder body and the bearing are integrated by fastening bolts penetrating in the axial direction of the crankshaft. Because
A deformation absorbing portion that guides deformation at the time of bolt fastening to at least one of a radially outward direction and a circumferential direction is provided in a region around the bolt hole of the cylinder body,
The rotary compressor according to claim 1, wherein the deformation absorbing portion is a groove provided in a region excluding a radially inner side from the bolt hole and penetrating in an axial direction of the crankshaft. A rotary compression mechanism driven via a crankshaft connected to a drive source; a cylinder body that forms a cylinder chamber; a bearing that is installed on each of the upper and lower surfaces of the cylinder body and supports the crankshaft; and the crank A rotary compressor having a rotor fitted in an eccentric part of a shaft and rotating in the cylinder chamber, wherein at least the cylinder body and the bearing are integrated by fastening bolts penetrating in the axial direction of the crankshaft. Because
The bolt hole peripheral area of the cylinder body is provided with a deformation absorbing portion for guiding the deformation during bolting to-out radially outward,
The deformation absorbing portion has a shape in which an outer peripheral surface of the cylinder main body is cut out in an axial direction of the crankshaft, and is located outside the bolt hole in the radial direction. Rotary compressor.

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