JP7660336B2 - Rotary Compressor - Google Patents

Description

The present invention relates to a rotary compressor .

Conventionally, a sealed electric rotary compressor, such as that shown in Patent Document 1, is known that includes a housing, a rotating shaft that extends vertically within the housing and is rotated by an electric motor, a rotary compression section having a cylinder supported by the rotating shaft, and upper and lower bearings that are rotatably supported by the rotating shaft and fixed above and below the cylinder.

JP 2015-17574 A

However, conventional rotary compressors have the following problems.
That is, in the past, the rotary compression section was generally made of a metal material because it needed to be strong enough to withstand the reaction force generated when compressing gas. On the other hand, there is a demand for rotary compressors to be small and lightweight to reduce noise. However, it is difficult to reduce the weight of a rotary compression section made of a metal material, and there is room for improvement in this regard.
Furthermore, since each component of the rotary compression section is made of metal material, it is necessary to mold them to highly accurate dimensions on the micron order in the cutting and grinding processes, which increases the number of processing steps and increases manufacturing costs.

The present invention has been made in consideration of the above-mentioned problems, and has an object to provide a rotary compressor that can reduce the weight of the entire rotary compressor and the manufacturing costs.

In order to achieve the above-mentioned object, a rotary compressor according to one embodiment of the present invention comprises a housing, a rotating shaft extending vertically within the housing, a cylinder supported by the rotating shaft and having a suction hole for allowing a refrigerant to flow into its interior, and an upper bearing and a lower bearing rotatably supported by the rotating shaft and fixed above and below the cylinder, wherein the housing has an opening formed at a position facing the outer peripheral surface of the cylinder, and further comprises a suction port inserted into the opening, one end communicating with the suction hole and the other end connected to a suction pipe that supplies the refrigerant, the cylinder is entirely molded from resin, the suction port is formed integrally with the cylinder by resin molding as a part of the cylinder, the cylinder is provided with a blade groove for slidably guiding a blade that divides an internal compression chamber in two, and a wear-resistant layer made of resin is formed on the inner surface of the blade groove as part of the cylinder .

According to the rotary compressor of the above aspect, the cylinder, which is the heaviest part of the rotary compressor, can be made lighter by molding it from resin, thereby making it possible to reduce the weight of the entire rotary compressor.
In addition, in this embodiment, the resin cylinder can be manufactured, for example, by extrusion molding or injection molding, and manufacturing costs can be reduced because there is no need for the high-precision, multi-step processing work such as cutting and grinding that is required for metal cylinders.
Furthermore, with this configuration, by forming an abrasion-resistant layer made of a material such as polyether ether ketone on the inner surface of the blade groove in the resin cylinder, the sliding characteristics of the blade guided in the blade groove can be improved.

The rotary compressor may also be configured such that at least one of the upper bearing and the lower bearing is made of resin.

According to this configuration, at least one of the upper bearing and the lower bearing fixed to the cylinder is made of resin by resin molding to reduce weight, thereby further reducing the weight of the entire rotary compressor.
Furthermore, with this configuration, a plastic bearing can be manufactured by, for example, extrusion molding or injection molding, eliminating the need for high-precision, multi-step processing such as cutting and grinding, as compared to metal bearings, and thereby reducing manufacturing costs.

In addition, it is preferable that the cylinder and the upper bearing or the lower bearing of the rotary compressor are integrally formed by resin molding.

With this configuration, the resin cylinder and either the upper or lower resin bearing can be molded as a single unit, reducing the number of processing steps and labor required compared to molding each separately, and molding can be done more efficiently, thereby reducing manufacturing costs.

According to the rotary compressor of the present invention, the weight of the entire rotary compressor can be reduced, and the manufacturing costs can be reduced.

1 is a vertical cross-sectional view showing a configuration of a rotary compressor according to an embodiment of the present invention. 2 is a cross-sectional view taken along line AA of FIG. 1, showing a horizontal cross-sectional view of a surface in the cylinder perpendicular to the central axis of the compressor.

The following describes a rotary compressor and a method for manufacturing a rotary compressor according to an embodiment of the present invention with reference to the drawings. This embodiment shows one aspect of the present invention, does not limit the present invention, and can be modified as desired within the scope of the technical concept of the present invention.

As shown in FIG. 1, the rotary compressor according to this embodiment (hereinafter simply referred to as compressor 1) is an example of a hermetically sealed electric rotary compressor used in, for example, air conditioners and refrigeration devices, and includes a compressor body 10, a suction pipe 11, and an accumulator 12.

The compressor body 10 includes a housing 2, a rotating shaft 3, an upper bearing 4A, a lower bearing 4B, an electric motor 5, and a rotary compression section 6. The rotary compression section 6 is provided with a disk-shaped cylinder 60 within the housing 2.
Here, the central axis of the housing 2 and the rotating shaft 3 are arranged on a common axis that extends vertically (up and down), and hereinafter this common axis is referred to as the rotation axis O. The rotating shaft 3 is arranged so that its extension direction is the vertical direction, and is accommodated within the housing 2 so as to be rotatable around the rotation axis O.

The housing 2 is sealed and extends in the vertical direction. The housing 2 has a cylindrical main body 21, and an upper lid 22 and a lower lid 23 that close the upper and lower openings of the main body 21. The housing 2 has an opening 24 formed in a position facing the outer circumferential surface of the cylinder 60 at the lower side wall. The cylinder 60 has an intake port 25 formed in a position facing the opening 24, which communicates with a predetermined position within the cylinder.

At the bottom of the housing 2, oil is stored to form an oil reservoir. When the oil is initially charged, the liquid level of the oil reservoir is located above the rotary compression section 6. This allows the rotary compression section 6 to be driven within the oil reservoir.

The upper lid 22 is provided with a discharge pipe 13 that penetrates in the thickness direction, has a lower portion disposed inside the housing 2, and an upper portion disposed outside the housing 2. The discharge pipe 13 discharges the compressed refrigerant, which contains oil, to the outside of the housing 2.

An accumulator 12 is provided on the outside of the housing 2 to separate the refrigerant into gas and liquid before supplying it to the compressor body 10. The accumulator 12 is fixed to the outer circumferential surface of the housing 2 via a bracket 14. The accumulator 12 is provided with the above-mentioned suction pipe 11 for sucking the refrigerant inside into the compressor body 10. The suction pipe 11 connected to the accumulator 12 is connected to the suction port 25 through an opening 24 of the housing 2. The accumulator 12 supplies the gas phase of the refrigerant to the rotary compression section 6 through the suction pipe 11.

The electric motor 5 is accommodated in the vertical center of the housing 2. The electric motor 5 has a rotor 51 and a stator 52. The rotor 51 is fixed to the outer circumferential surface of the rotating shaft 3, and is disposed above the rotary compression unit 6. The stator 52 is disposed so as to surround the outer circumferential surface of the rotor 51, and is fixed to the inner surface 21 a of the main body 21 of the housing 2.
A power source (not shown) is connected to the electric motor 5 configured as above. The electric motor 5 is configured to rotate the rotary shaft 3 by electric power from the power source.

The upper bearing 4A and the lower bearing 4B are arranged so as to sandwich the rotary compression unit 6 from above and below. The upper bearing 4A and the lower bearing 4B are each made of a metal material, and are fixed to a cylinder 60 constituting the rotary compression unit 6 with a bolt 61.
The rotating shaft 3 is supported rotatably about a rotation axis O by an upper bearing 4A and a lower bearing 4B.

The rotary compression section 6 is disposed at the bottom of the housing 2 below the electric motor 5. The rotary compression section 6 has a cylinder 60, an eccentric shaft section 62, and a piston rotor 63.

The cylinder 60 has a compression chamber 60A, a suction hole 60B, and a discharge hole (not shown). The compression chamber 60A is formed inside the cylinder 60. The compression chamber 60A houses a piston rotor 63.

The cylinder 60 is entirely made of resin. Resin materials that can be used for the cylinder 60 are lightweight, heat-resistant, and high-strength materials, such as PBT (polybutylene terephthalate), PPS (polyphenylene sulfide), and PEEK (polyether ether ketone). Such resin cylinders 60 can be manufactured using molding methods such as extrusion molding, injection molding, or print molding using a 3D printer.

The resin cylinder 60 is fixed to the inner surface 21a of the main body 21 of the housing 2. The symbol P in Figs. 1 and 2 indicates the fixing portion between the housing 2 and the cylinder 60. The method of fixing the cylinder 60 to the housing 2 can be shrink fitting, cold fitting, or resin melting.

The eccentric shaft portion 62 is provided at the lower end of the rotating shaft 3 and is offset in a direction perpendicular to the central axis of the rotating shaft 3 inside the piston rotor 63 .
The piston rotor 63 has a cylindrical shape with an outer diameter smaller than the inner diameter of the cylinder 60, is disposed inside the cylinder 60, and is inserted into and fixed to the eccentric shaft portion 62. The piston rotor 63 rotates eccentrically with respect to the rotation axis O in conjunction with the rotation of the rotating shaft 3.

The suction hole 60B is a hole that allows the refrigerant to flow into the inside of the cylinder 60.
The refrigerant compressed by the rotary compression section 6 is discharged through a discharge hole (not shown) into the internal space of the housing 2, which is kept at an intermediate pressure.

As shown in FIG. 2, the cylinder 60 is provided with a blade 64 that divides the compression chamber 60A into two. The cylinder 60 is formed with a blade groove 65 that extends in the radial direction. The blade 64 is slidably guided along the inner surface 65a of the blade groove 65 and is held so as to be able to move forward and backward in a direction toward and away from the piston rotor 63. The base end 64b of the blade 64 on the outer radial side is elastically pressed by a compression spring (not shown), and the tip end 64a is always pressed against the outer peripheral surface 63a of the piston rotor 63.

The blade groove 65 has an inner surface 65a, which is the sliding portion with the blade 64, on which an abrasion-resistant layer 66 that has the abrasion resistance of the resin cylinder 60 is formed. Examples of the abrasion-resistant layer 66 include resins such as PEEK (polyether ether ketone), PTFE (polytetrafluoroethylene), PES (polyethersulfone), and LCP (liquid crystal polymer).

The eccentric shaft portion 62 has an outer diameter slightly smaller than the inner diameter of the piston rotor 63. As a result, when the rotating shaft 3 rotates, the eccentric shaft portion 62 revolves around the rotating shaft 3, and the piston rotor 63 rolls eccentrically inside the cylinder 60. At this time, the blade 64 is pressed by a compression spring (not shown), so the tip portion 64a moves forward and backward following the movement of the piston rotor 63, and is constantly pressed against the piston rotor 63.

In this type of compressor 1, refrigerant is taken into the accumulator 12, the refrigerant is separated into gas and liquid within the accumulator 12, and the gas phase is supplied from the suction pipe 11 through the suction port 25 of the cylinder 60 to the compression chamber 60A, which is the internal space of the cylinder 60.
The eccentric rotation of the piston rotor 63 gradually reduces the volume of the compression chamber 60A, compressing the refrigerant. A discharge hole (not shown) for discharging the refrigerant is formed at a predetermined position of the cylinder 60, and this discharge hole is equipped with a reed valve (not shown). As a result, when the pressure of the compressed refrigerant increases, the reed valve is pushed open and the refrigerant is discharged to the outside of the cylinder 60. The discharged refrigerant is discharged from a discharge pipe 13 provided at the top of the housing 2 to an external piping (not shown).

Next, the operation of the above-described rotary compressor and the manufacturing method of the rotary compressor will be specifically described with reference to the drawings.
In the compressor 1 according to the present embodiment, as shown in FIGS. 1 and 2 , the cylinder 60, which is the heaviest part of the rotary compressor 1, is made of resin, thereby making it possible to reduce the weight, and thereby making it possible to reduce the weight of the entire rotary compressor 1.

In addition, in this embodiment, the resin cylinder 60 can be manufactured by, for example, extrusion molding or injection molding, and manufacturing costs can be reduced because there is no need for the high-precision, multi-step processing work of cutting and grinding required for metal cylinders.

Furthermore, in this embodiment, as shown in FIG. 2, an abrasion-resistant layer 66 made of a material such as polyether ether ketone is formed on the inner surface 65a of the blade groove 65 in the resin cylinder 60, thereby improving the sliding characteristics of the blade 64 guided into the blade groove 65.

Furthermore, as a manufacturing method for the compressor 1 according to this embodiment for fixing the resin-molded cylinder 60 to the housing 2, a fixing method can be adopted that includes a process of resin-molding the entire cylinder 60 and a process of fixing the resin-molded cylinder 60 to the inner surface 21a (fixing portion P) of the main body portion 21 of the housing 2 by shrink fitting, cold fitting, or resin melting. Therefore, the resin cylinder 60 can be reliably and easily fixed to the inner surface 21a of the housing 2.

The rotary compressor and the manufacturing method for the rotary compressor according to the present embodiment described above can reduce the weight of the entire compressor 1, thereby reducing manufacturing costs.

The above describes the embodiments of the rotary compressor and the manufacturing method for the rotary compressor according to the present invention, but the present invention is not limited to the above embodiments and can be modified as appropriate without departing from the spirit of the invention.

For example, in this embodiment, the upper bearing 4A and the lower bearing 4B are formed from a metal material, but they are not limited to being made of metal, and at least one of the upper bearing 4A and the lower bearing 4B may be configured to be molded from resin.
In this case, the weight of at least one of the resin-molded upper bearing and lower bearing can be reduced, further reducing the weight of the entire rotary compressor. Also, since resin bearings can be manufactured by, for example, extrusion molding or injection molding, they do not require the high-precision, many-manufacturing processes such as cutting and grinding that are required in comparison with metal bearings, thereby reducing manufacturing costs.

In addition, in this embodiment, the cylinder 60, the upper bearing 4A, and the lower bearing 4B are each configured as separate bodies, but either one of the upper bearing 4A and the lower bearing 4B may be formed integrally with the cylinder 60 by resin molding.
In this case, the number of processing steps and the labor required for the work can be reduced compared to when each part is resin molded separately, and molding can be performed efficiently, thereby reducing manufacturing costs. By molding the cylinder 60 and the bearing 4A (4B) as a single unit, it is no longer necessary to join them by bolting, which reduces the number of parts and the time and cost required for processing.

In addition, in this embodiment, the suction pipe 11 connected to the accumulator 12 is connected, and the suction port 25 that communicates with the compression chamber 60A of the cylinder 60 is also provided separately from the cylinder 60, but this suction port 25 can also be configured to be integral with the cylinder 60 by resin molding as part of the cylinder 60.

Furthermore, in this embodiment, a resin wear-resistant layer 66 is formed on the inner surface 65a of the blade groove 65 of the cylinder 60, but it is also possible to omit the wear-resistant layer 66 in this area (the inner surface 65a of the blade groove 65).

Furthermore, the shape, size, and other configurations of the housing 2, rotating shaft 3, upper bearing 4A, lower bearing 4B, electric motor 5, rotary compression section 6 (cylinder 60, eccentric shaft section 62, piston rotor 63), and accumulator 12 can be set as appropriate.

In addition, the components in the above-described embodiments may be replaced with well-known components as appropriate without departing from the spirit of the present invention, and the above-described embodiments may be combined as appropriate.

1. Compressor (rotary compressor)
Reference Signs List 2 Housing 3 Rotating shaft 4A Upper bearing 4B Lower bearing 5 Electric motor 6 Rotary compression section 10 Compressor body 12 Accumulator 21 Body section 21a Inner surface 60 Cylinder 60A Compression chamber 62 Eccentric shaft section 63 Piston rotor 64 Blade 65 Blade groove 65a Inner surface 66 Wear-resistant layer O Rotation axis P Fixed section

Claims (3)

Housing and
a rotating shaft extending vertically within the housing;
a cylinder supported by the rotating shaft and having a suction hole for allowing a refrigerant to flow therein;
an upper bearing and a lower bearing rotatably supported by the rotating shaft and fixed to the top and bottom of the cylinder;
Equipped with
The housing has an opening formed at a position facing an outer circumferential surface of the cylinder,
a suction port that is inserted through the opening, has one end that communicates with the suction hole, and has the other end that is connected to a suction pipe that supplies the refrigerant;
The cylinder is entirely made of resin,
the intake port is provided as a part of the cylinder by resin molding so as to be integrated with the cylinder ,
The cylinder is provided with a blade groove for slidably guiding a blade that divides the internal compression chamber into two.
A resin wear-resistant layer is formed on the inner surface of the blade groove as a part of the cylinder.
Rotary compressor. The rotary compressor according to claim 1, wherein at least one of the upper bearing and the lower bearing is made of resin. The rotary compressor according to claim 1 or 2, in which the cylinder and the upper bearing or the lower bearing are integrally formed by resin molding.

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