Rotary Compressor

Abstract

To improve a lubricating oil circulation rate in a rotary compressor by suppressing the release of the lubricating oil associated with reduction in size and weight of the rotary compressor.SOLUTION: The rotary compressor is provided that comprises: a housing 2; a rotary shaft 3 having a lower portion on which a cylinder 60 is supported and extending in the vertical direction in the housing 2; and a delivery pipe 13 which penetrates through an upper lid portion 22 of the housing 2 in the thickness direction and has a lower portion 13A disposed in the housing 2 and an upper portion 13B disposed outside the housing 2 and delivers a refrigerant compressed in the housing 2 to the outside of the housing 2. A lower end 13a of the delivery pipe 13 is disposed close to a position facing an upper end 3a of the rotary shaft 3. The rotary compressor satisfies a numerical expression (1): D≤L≤5D, where D (mm) denotes the inner diameter of the delivery pipe 13 and L (mm) denotes a distance between the upper end 3a of the rotary shaft 3 and the lower end 13a of the delivery pipe 13.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a rotary compressor. [Background technology]

[0002] Conventionally, as an example of a hermetic electric rotary compressor, as shown in Patent Document 1, there has been known one that includes a housing, a rotating shaft that extends vertically within the housing and has a cylinder supported at its lower part, and a discharge pipe that penetrates the top wall of the housing in the thickness direction, has a lower part located within the housing and an upper part located outside the housing, and discharges refrigerant compressed within the housing to the outside of the housing. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-17574 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, conventional rotary compressors are required to be smaller and lighter. When the space required for a rotary compressor is reduced by making it smaller and lighter, some of the lubricating oil that is mixed in the refrigerant and circulates with the refrigerant is easily discharged outside the housing through the discharge pipe, which increases the oil circulation rate, leaving room for improvement in this respect.

[0005] 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 oil circulation rate by suppressing the release of lubricating oil that accompanies size and weight reduction. [Means for solving the problem]

[0006] In order to achieve the above object, a rotary compressor according to one aspect of the present invention includes a housing, a rotating shaft having a cylinder supported at a lower portion thereof and extending in a vertical direction within the housing, and a discharge pipe provided coaxially with the rotating shaft, penetrating a top wall portion of the housing in a thickness direction, and discharging a refrigerant compressed within the housing to an outside of the housing, wherein the rotating shaft is a first cylindrical member having a constant outer diameter over its entire length. and a shaft tapered portion having a diameter that decreases from the upper end of the first cylindrical member toward the upper side, The discharge pipe is a second cylindrical member having a constant outer diameter over its entire length. and a different diameter portion extending upward from the second cylindrical member, The discharge pipe 2 Cylindrical member At the bottom a chisel protruding downward from the top wall of the housing; Second cylindrical member The lower end of Shaft taper and the upper end of the housing are disposed in close proximity to each other at a position directly opposed to each other through only the internal space of the housing, Second cylindrical member When the inner diameter of the Shaft taper The upper end and Second cylindrical member The distance L (mm) between the lower end of the

[0007]

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[0008] According to the rotary compressor of the above aspect, by bringing the rotating shaft close to the discharge pipe and setting the distance L between the upper end of the rotating shaft and the lower end of the discharge pipe within the range of the above formula (1), the lubricating oil can be collided with the rotating shaft near the discharge pipe, and the oil droplet flow rate can be reduced. This makes it possible to prevent the lubricating oil from being discharged to the outside of the housing through the discharge pipe. Note that when the distance L is smaller than D and the discharge pipe and the rotating shaft are close to each other, pressure loss is likely to occur in the compressed refrigerant. Also, when the distance L is larger than 5D and the discharge pipe and the rotating shaft are separated from each other, the amount of lubricating oil discharged increases. In this way, in the rotary compressor according to the present embodiment, the release of lubricating oil that accompanies the reduction in size and weight can be suppressed, and therefore the oil circulation rate can be reduced. Therefore, even a small and lightweight rotary compressor can be operated without improving the oil circulation rate.

[0009] The rotary compressor further comprises: Second cylindrical member The inner diameter D may be configured to satisfy the following formula (2).

[0010]

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[0011] In this case, by setting the inner diameter D of the discharge pipe within the range of the above formula (2), the lubricating oil can be made to collide with the rotating shaft near the discharge pipe, and the effect of slowing down the flow rate of the oil droplets can be more effectively achieved. If the inner diameter D of the discharge pipe is smaller than 2 mm, a pressure loss occurs due to the smaller inner diameter of the discharge pipe. Also, if the inner diameter D of the discharge pipe is larger than 15 mm, the area of ​​collision with the rotating shaft when the lubricating oil droplets flow into the discharge pipe with the discharge gas flow decreases, making it impossible to slow down the flow rate of the lubricating oil droplets, and the oil circulation rate remains the same as that of the current market products. Effect of the Invention

[0012] According to the rotary compressor of the present invention, the oil circulation rate can be reduced by suppressing the release of lubricating oil that accompanies reduction in size and weight. [Brief description of the drawings]

[0013] [Figure 1] 1 is a vertical cross-sectional view showing a configuration of a rotary compressor according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, a rotary compressor according to an embodiment of the present invention will be described with reference to the drawings. The embodiment shows one aspect of the present invention, and does not limit the present invention. The embodiment can be arbitrarily modified within the scope of the technical concept of the present invention.

[0015] As shown in FIG. 1, the rotary compressor according to this embodiment (hereinafter simply referred to as compressor 1) is an example of a hermetic electric rotary compressor used in, for example, an air conditioner or a refrigeration device, and includes a compressor body 10, a suction pipe 11, and an accumulator 12.

[0016] 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 unit 6. The rotary compression unit 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.

[0017] 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 (top wall) 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 a cylinder 60 at the lower part of the side wall. The cylinder 60 has a suction port 25 formed in a position facing the opening 24, which communicates with a predetermined position within the cylinder 60.

[0018] An oil sump is formed by storing oil (lubricating oil) at the bottom of the housing 2. The liquid level of the oil sump when the lubricating oil is initially charged is located above the rotary compression section 6. This allows the rotary compression section 6 to be driven within the oil sump.

[0019] Upper cover 22 is provided with discharge pipe 13 that penetrates in the thickness direction, has a lower portion 13A disposed inside housing 2, and has an upper portion 13B disposed outside housing 2. Discharge pipe 13 discharges the compressed refrigerant, which contains lubricating oil, to the outside of housing 2.

[0020] The lower end 13a of the discharge pipe 13 is disposed adjacent to a position facing the upper end 3a of the rotating shaft 3. In this embodiment, the pipe axis of the discharge pipe 13 is disposed coaxially with the rotation axis O (the central axis of the rotating shaft 3), but they are not limited to being coaxial. In other words, the rotating shaft 3 and the discharge pipe 13 may be misaligned from each other when viewed from the direction of the rotation axis O.

[0021] In the compressor 1, when the inner diameter of the discharge pipe 13 is D (mm), the distance L (mm) between the upper end 3a of the rotating shaft 3 and the lower end 13a of the discharge pipe 13 is set to satisfy the following formula (1). When the distance L is smaller than D and the discharge pipe 13 and the rotating shaft 3 are close to each other, pressure loss is likely to occur in the compressed refrigerant. When the distance L is larger than 5D and the discharge pipe 13 and the rotating shaft 3 are far apart, the amount of lubricating oil discharged increases. It is more preferable that the range of the inner diameter D of the discharge pipe 13 is set so as to satisfy the following formula (2). In other words, if the inner diameter D of the discharge pipe 13 is smaller than 2 mm, a pressure loss occurs due to the small inner diameter of the discharge pipe. Also, if the inner diameter D of the discharge pipe 13 is larger than 15 mm, the area of ​​collision with the rotating shaft 3 when the lubricating oil droplets flow into the discharge pipe 13 with the discharge gas flow decreases, making it impossible to decelerate the flow rate of the lubricating oil droplets, and the oil circulation rate remains the same as that of the current market product. Further, it is more preferable that the inner diameter D of the discharge pipe 13 is 2.5 mm or more and 13 mm or less (2.5 mm≦D≦13 mm).

[0022]

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[0023]

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[0024] An accumulator 12 is provided outside the housing 2 for separating the refrigerant into gas and liquid phases before supplying the refrigerant 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 a suction port 25 through an opening 24 of the housing 2. The accumulator 12 supplies the gas phase refrigerant to the rotary compression section 6 through the suction pipe 11.

[0025] 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 21a of the main body portion 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 rotating shaft 3 by the electric power from the power source.

[0026] 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 that constitutes 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.

[0027] The rotary compression unit 6 is disposed at the bottom within the housing 2 below the electric motor 5. The rotary compression unit 6 has a cylinder 60, an eccentric shaft portion 62, and a piston rotor 63.

[0028] 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 accommodates a piston rotor 63. The cylinder 60 is fixed to the inner surface 21 a of the main body 21 of the housing 2 .

[0029] The eccentric shaft portion 62 is provided at the lower end of the rotating shaft 3 and is provided inside the piston rotor 63 in a state where it is offset from the central axis of the rotating shaft 3 in a direction perpendicular to the central axis of the rotating shaft 3 . 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 as the rotating shaft 3 rotates.

[0030] 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.

[0031] The cylinder 60 is provided with a blade (not shown) that divides the compression chamber 60A into two and is elastically pressed by a compression spring (not shown) so that its tip is always pressed against the outer circumferential surface of the piston rotor 63.

[0032] 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 within the cylinder 60.

[0033] In such a 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. Then, due to the eccentric rotation of the piston rotor 63, the volume of the compression chamber 60A gradually decreases, 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).

[0034] Next, the operation of the above-mentioned rotary compressor will be specifically described with reference to the drawings. In the compressor 1 according to this embodiment, as shown in FIG. 1, by bringing the rotating shaft 3 close to the discharge pipe 13 and setting the distance L between the upper end 3a of the rotating shaft 3 and the lower end 13a of the discharge pipe 13 within the range of the above formula (1), the lubricating oil can be made to collide with the rotating shaft 3 near the discharge pipe 13, thereby slowing down the oil droplet flow velocity. This makes it possible to prevent the lubricating oil from being discharged to the outside of the housing 2 via the discharge pipe 13.

[0035] Furthermore, in this embodiment, by setting the inner diameter D of the discharge pipe 13 within the range of the above formula (2), the lubricating oil can be collided with the rotating shaft 3 near the discharge pipe 13, and the effect of slowing down the oil droplet flow rate can be more effectively achieved.

[0036] In this way, the compressor 1 according to the present embodiment can suppress the release of lubricating oil that accompanies the reduction in size and weight, and therefore can reduce the oil circulation rate. Therefore, even the small and lightweight rotary compressor 1 can be operated without improving the oil circulation rate.

[0037] Although the embodiment of the rotary compressor according to the present invention has been described above, the present invention is not limited to the above embodiment and can be modified as appropriate without departing from the spirit and scope of the present invention.

[0038] For example, in this embodiment, the inner diameter D of the discharge pipe 13 is set to satisfy the above (2), but the inner diameter D of the discharge pipe 13 may be configured only by setting the distance L between the upper end 3a of the rotating shaft 3 and the lower end 13a of the discharge pipe 13 without limiting the numerical range of the inner diameter D of the discharge pipe 13.

[0039] In addition, in this embodiment, the upper lid portion 22 is the top wall portion through which the discharge pipe 13 passes in the housing 2, but the discharge pipe 13 may also be provided in the top wall portion of a housing having a configuration in which the main body portion 21 and the upper lid portion 22 are integrated.

[0040] In addition, 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 to any appropriate configuration.

[0041] In addition, within the scope of the invention, the components in the above-described embodiments may be replaced with well-known components, and the above-described embodiments may be combined as appropriate. [Explanation of symbols]

[0042] 1 Compressor (rotary compressor) 2. Housing 3 Rotating shaft 3a top edge 4A Upper bearing 4B Lower bearing 5. Electric motor 6 Rotary Compression Section 10 Compressor body 12 Accumulator 13 Discharge pipe 13a Bottom end 21 Main body 22 Upper lid (top wall) 23 Lower lid 60 cylinders O Rotation axis

Claims

1. Housing and a rotating shaft having a cylinder supported at its lower portion and extending vertically within the housing; a discharge pipe that is provided coaxially with the rotating shaft, that penetrates a top wall portion of the housing in a thickness direction, and that discharges the refrigerant compressed in the housing to an outside of the housing; Equipped with The rotating shaft includes a first cylindrical member having a constant outer diameter over its entire length, and a shaft taper portion whose diameter decreases from an upper end of the first cylindrical member toward an upper portion, an upper portion of the first cylindrical member protrudes above a rotor fixed to an outer circumferential surface of the rotating shaft; the discharge pipe includes a second cylindrical member having a constant outer diameter over the entire length, and a different diameter portion extending upward from the second cylindrical member, Only a lower portion of the second cylindrical member of the discharge pipe protrudes downward from the top wall portion of the housing, The lower end of the second cylindrical member and the upper end of the shaft tapered portion are disposed in close proximity to each other in a position directly facing each other with only the internal space in the housing interposed therebetween, a distance L (mm) between an upper end of the shaft tapered portion and a lower end of the second cylindrical member satisfies the following formula (1), when an inner diameter of the second cylindrical member is D (mm). [0010]

2. The rotary compressor according to claim 1 , wherein an inner diameter D of the second cylindrical member satisfies the following formula (2): [0025]

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